11th International Symposium on High-Temperature Metallurgical Processing

A hydraulic modelHydraulic model with a similarity ratio of 1:4 was used to simulate the blowing parameters of 65t electric arc furnaceElectric arc furnace (EAF) (EAFElectric arc furnace (EAF)). The molten bath stirring effects of different bottom blowing arrangements and flow ratesFlow Rates under different combined blowingCombined blowing conditions were studied. On this basis, orthogonal experiments were designed to study the effects of bottom blowing rate, side blowing rate, and bottom blowing arrangement on the mixingMixing time of molten bath. The results showed that the bottom blowing arrangement has little effect on the mixingMixing time of molten pool. Under the condition of combined blowingCombined blowing, the degree of influencing factors on mixingMixing time from big to small was the side blowing rate, bottom blowing rate, and bottom blowing arrangement. The industrial experiment showed that, compared with traditional process, the combined blowingCombined blowing process can increase the decarbonization rate and reduce the consumption of ironIron and steelSteel materials.

A new argon blowing modeArgon blowing mode with different flowrates for two purging bricks of a 70t steelmaking ladleLadle has been explored in the present work. The mixingMixing behaviour of the molten steelSteel and the slag eyeSlag eye change were revealed by using a 1:3 scale factor of water model. The results show that, compared with the conventional mode with the same flowrate for each brick, the new mode effectively decreases the mixingMixing time, and the total area of the slag eyeSlag eye changes slightly. The shortest mixingMixing time was obtained by the case in which the brick locations are at 0.6 R with a 180° relative angleAngle and a 22 L/min total flowrate.

In this work, the interaction of FeO with MgOMgO-14.5 wt% C refractoryRefractory under the conditions of the novel flash ironmakingFlash ironmaking technology (FIT) has been investigated. Carbon from the refractoryRefractory was oxidized and the formation of magnesiowustite (MgxFe1−xO) solid solution took place as a result of the interaction between FeO and MgOMgO. A kinetic model for the growth of magnesiowustite was developed based on the counterdiffusion of Fe2+ and Mg2+ cations and experiments were conducted with FeO and MgOMgO-14.5 wt% C refractoryRefractory in the temperatureTemperature range 1200–1400 °C. The analyses of samples using SEM-EDX and EPMAEPMA confirmed the oxidation of carbon and the formation of magnesiowustite.Magnesiowustite. Using the kinetic model and the composition profiles determined from EPMAEPMA scans, the values of interdiffusion coefficient, averaged over the composition range ($$ \bar{D}_{Fe - Mg} $$), were calculated at all the experimental temperatures. The activation energyActivation energy for the solid-state diffusionSolid-state diffusion process was obtained to be 398 kJ/mol.

The narrow window controlNarrow window control of the converter end-point carbon content and temperatureTemperature is the main target for improving the refining level and achieving intelligent manufacturing. According to the practical data of Q235 steelSteel obtained in converter production, the operation process parameters were discreted based on the chi-square boxing methodChi-square boxing method combined with the ideal target interval of end-point carbon content and temperatureTemperature. At the same time, the key process parameter affecting the ideal end-point of the converter was guided by WOE value, and the coded data was scored by logistic regressionLogistic regression algorithm. The evaluation modelEvaluation model of converter operation process established in this paper can reasonably identify the bad operating process parameters, and the recall ratio of the converter production data that does not meet the ideal end-point target interval is 84%, and the accuracy ratio of evaluation modelEvaluation model is 88%. In addition, the evaluation results indicate that the carbon content and silicon content of the hot metal are the main factors affecting the convert end-point of this steelSteel plant, and thus, optimizing the condition of hot metal can achieve the purpose of narrow window controlNarrow window control on the converter endpoint.

This work models the design of a preheater (shaft kilnShaft kiln ) to demonstrate preheating of manganese oresManganese ores with hot air at 800 °C produced by concentrating solar thermal energy on a pilot scale. This paper reports the methodology for the development of a heat and mass transferHeat and mass transfer model that informs the effective control of the shaft kilnShaft kiln air flow ratesFlow Rates . A continuum approach is followed through the discretisation of the fluid and solid phases of a packed bedPacked bed of randomly packed lumpy mineral ore. The fluid dynamics of the packed bedPacked bed is solved using correlations for fluid flow through packed beds and the dimensionless constants for flow, heat convectionConvection and conductionConduction are quantified for a packed bedPacked bed of manganese ore. The required pressure drop across the shaft kilnShaft kiln with fluid flow up to 5 m/s is less than 100 kPa. It was also found that a lumped system does not exist in the solid phase. The validity of the model will be studied theoretically and through experimental work. Outstanding work on the methodology includes the solution to the radiative heat transfer, convective mass transfer, and the method to measure the extent to which the wall effect impacts on the radial temperatureTemperature distribution.

In this paper, according to the large-capacity tundish with single-strand and rectangular structure, the mathematical simulation method is used to study the effect of the flow control devicesFlow control devices of the weir and the dam on the flow fieldFlow field, temperatureTemperature field, and inclusionsInclusions trajectories of molten steelSteel. The orthogonal experiment method is used to study the effect of the distance between the weir and the bottom of the tundish, the distance from the weir to the long nozzle, the distance between the weir and the dam, the heightHeight of the dam on the flow pattern, temperatureTemperature distribution, and inclusion removal rateInclusion removal rate of the molten steelSteel in tundish. The reasonable flow control devicesFlow control devices and the installation position could be obtained by analyzing the results of mathematical simulation, and it can provide theoretical guidance for actual production.

The combined coal gasificationCoal gasification and flash ironmakingFlash ironmaking process (CG-FI) was the latest technology practice of the alternative ironmaking process, and it can also be recognized as a multi-generation systemMulti-generation system for high-quality syngas and reduced ironIron . The computational fluid dynamicsComputational Fluid Dynamics (CFD) model was established to explore the process conditions based on the pilot-scalePilot-scale equipment. The turbulent flow, gas–particle coupling, and kinetic reaction model were considered in the model, which was already validated in the prior researches. In this study, the different material ratio combinations, including oxygen/coal ratio (0.6–0.8) and ore/coal ratio (0.2–1.6), were investigated to illuminate the interrelationship during the gasification–reduction coupling processGasification–reduction coupling process . The results demonstrated that the qualified reduced ironIron (ReductionReduction Degree = 52.47%) could be obtained even in the worst case (oxygen/coal ratio = 0.6, ore/coal ratio = 1.6). Moreover, the dispersed hematite particles replaced the role of H2O as the coolant and partial oxidant in the traditional coal gasificationCoal gasification process to improve the gasificationGasification performance.

Lead anode slimeLead anode slime (LAS), a significant by-product for Ag and Au recoveryRecovery, is produced from lead electro-refining process. The volume of Ag recycled from LAS accounts for approximately 60% share of global silverSilver production. Limited understanding of complex characteristics of the metals in LAS and prominent problems of difficult efficient separation, complex process, and serious environmental pollution in traditional LAS processing for PMs recoveryRecovery have been highlighted as significant knowledge gaps. An innovative directional vacuum volatilization of LAS for Ag and Au enrichment is therefore proposed. Results indicated that Ag and Au were successfully enriched in residues, while impurities of As2O3, Sb2O3, etc., were collected in volatiles. The direct recoveryRecovery of Ag and Au reached 99.0%. Vacuum strategy not only effectively extracted Ag and Au but also avoided arsenic contamination. The finding will be significant to benefit decision-making direction for clean-efficient utilization of LAS.

The element boron has an important influence on the conversion efficiency of solar cells of silicon. In this study, the effects of the electrolytic parametersElectrolytic parameters (electrolysisElectrolysis temperatureTemperature , current density, and concentration of Si in melt) on the deposition of B at the cathode were studied during the molten salt electrolysis for siliconMolten salt electrolysis for silicon in Na3AlF6–SiO2 meltNa3AlF6–SiO2 melt . ICP analysis shows that the deposition content of B at the cathode is decreased with the increase in electrolysisElectrolysis temperatureTemperature , but is increased with the increase in current density. Moreover, increasing the concentration of Si in melt is unfavorable for B to deposit at the cathode. Accordingly, by adjusting the electrolytic parametersElectrolytic parameters , the deposition of B can be controlled.

TCOX9 is a thermodynamicThermodynamic database (developed using CALPHADCALPHAD) which describes the thermochemical interactions between liquid steelSteel and slagSlag during steel makingSteel making and refining. It contains all the major steelSteel alloying elements (Fe–C–Co–Cr–Cu–Mn–Mo–Nb–Ni–V–W–Ti) as well as the most important slagSlag elements (Ca–Mg–Si–Al–F–O–P–S). The ionic liquid model describes the liquid phase over the whole composition range from metallic liquid (steelSteel) to oxide liquid (slagSlag). The database also contains the most important metallic and non-metallic solid phases, allowing the calculation of inclusionInclusion formation, inclusionInclusion modification, steelSteel solidificationSolidification, slagSlag solidificationSolidification, steelSteel–refractoryRefractory reactions, slagSlag–refractoryRefractory reactions, and steelSteel–mould powder reactions. For use with this database, a new process metallurgyProcess metallurgy module has been developed within Thermo-Calc which makes it easy to set up calculations for steelSteel and slagSlag. An extension to the module is under development that incorporates a kinetic model of the steelmaking process based on the concept of effective equilibrium reaction zones. This model is outlined in detail in this paper and applied to a ladleLadle furnace steel refiningSteel refining process.

The effect of oxygen supply systems and slagSlag composition on dephosphorization rateDephosphorization rate in the early stage of smelting was studied. Metal samples, slagSlag samples, and molten steelSteel temperatures of a 300t converter300t converter at different smelting stages were analyzed. The alkalinity of slagSlag was found to be the lowest at 1.33 during the early stage of the experiment, superheat was 7 °C, the mass fraction of C3MS2 phase was 35 wt%, and average dephosphorization rateDephosphorization rate was 32.2%. By optimizing the oxygen supply system and charging system of the converter, the alkalinity of slagSlag was controlled in the range of 1.6–2.1 and the average content of T.Fe was 15 wt%. The results demonstrated a 10.2% increasment in dephosphorization rateDephosphorization rate during the early stage of smelting, 5.9% increasment in the scrap steelSteel ratio, 31 °C increasment in the tapping temperatureTemperature, and 0.65% increasment in the final dephosphorization rateDephosphorization rate.

A crack-free cube was manufactured by depositing spherical GE Ti4822Ti4822 alloy alloyAlloy powder using a laser direct metal deposition technique. Tensile specimens were wire cut and tested for tensile propertiesTensile properties. Three kinds of specimen were tested: the as-built and those that were heat treated in an argon rich environment at 1200 °C and 1400 °C and oven cooled. The results showed that the as-built samples had high UTS (440.68 MPa) and very poor elongation (0.11%) while samples that were heat treated at 1200 °C and 1400 °C had UTS of 382.95 MPa and 297.60 MPa, respectively. All samples lacked plasticity. This study concluded that a coarse-grained fully lamellar microstructureMicrostructure had low tensile strength which would suggest moderate toughness and ductility at room temperatureTemperature.

As people pay more and more attention to environmental protection, energy conservation in the whole process of steelSteel manufacturing has become a hot research object. China’s steelSteel manufacturing process has a history of energy conservation for more than 40 years. The total energy consumption per ton of steelSteel of large and medium-sized enterprises has dropped from 1.646tce/t to 555.24kgce/t. This paper puts forward a new theory of process reconstructionProcess reconstruction, which is mainly explained from the following three aspects: analysis-optimization of the set of procedures’ functions, coordination-optimization of the set of procedures’ relations, and reconstruction-optimization of the set of process’ procedures. Then, the paper expounds the relationship between process reconstructionProcess reconstruction and energy savingEnergy saving from two aspects: interface technologyInterface technology and synergy of material flowMaterial flow and energy flow. After applying the new process reconstructionProcess reconstruction technology, the energy-savingEnergy-saving effect of about 5% was achieved in the steelSteel plant experiment. Finally, the research direction of energy conservation in steelSteel manufacturing process is proposed.

Mould fluxFlux is of great importance in the metal continuous casting process, and mainly the calcium fluoride is always added. On the other hand, electromagnetic field is also used in the mould for improving the quality of metal. Thus, the knowledge of the structural and transported properties ofCaO–SiO2–CaF2 flux CaO–SiO2–CaF2CaF2 fluxFlux under magnetic fieldMagnetic field are relevant properties for industry applications for the sake of prevention of operation problem and product defect. In this paper, molecular dynamicsMolecular dynamics is used to investigate the effect of magnetic fieldMagnetic field on the CaO–SiO2–CaF2CaF2 fluxesCaO–SiO2–CaF2 flux at 1773 K, applying 12 models changed on their chemical compositions and intensities of magnetic fieldMagnetic field . The results show that the magnetic fieldMagnetic field can increase the complexity of micro-structures and the mobility of F− ion in fluxes, revealing the growth of summation of Q3 and Q4 species as the intensity of magnetic climbing, as well as with the concentration of bridging oxygen rising.

A better understanding of crack initiation and propagation in duplex stainless steelSteel (DSS) during hot workingHot working process is significant for improving production efficiency, due to the frequent occurrence of cracking during deformation process of duplex stainless steels. In this work, the cracking mechanism of S32750 super duplex stainless steelSteel (SDSSSDSS) during hot rolling was researched in detail. The results showed that uneven deformation can easily cause the crack initiation and propagation. The hard and brittle sigma phases with high Cr and Mo, which were observed near the cracksCracks, seriously damaged the hot workingHot working properties of SDSSSDSS. During hot deformation, nitride, as another high temperatureTemperature phases, precipitated along grain boundaries to prevent grain boundary migration, and further to reduce the hot ductility of steelSteel. InclusionsInclusions can also cause crack initiation and propagation, especially Al2O3. In addition, the surface microcracks resulting from oxide layer rolled into the matrix.

Al2O3 and ZrO2 refractories are widely used in the steelSteel industry as lining materials for many metallurgical reactors. Since the refractoryRefractory material is in direct contact with the slagSlag and molten steelSteel, it is susceptible to corrosionCorrosion and degradation, particularly on the slagSlag line. The corrosionCorrosion behavior of high-basicity refining slagHigh-basicity refining slag to refractories was studied in this paper. The results show that Al2O3 refractories would partially dissolve into the slagSlag, and form a transition layer composed of CaAl12O19 and CaAl4O7. For ZrO2 refractories, the slagSlag and the ZrO2 crucible produce a transition layer composed of CaZrO3, CaZr4O9, and Ca6Zr19O44, which prevents the further corrosionCorrosion of the crucible. The corrosionCorrosion mechanism was studied by experiments combined with thermodynamicThermodynamic calculations and the establishment of new corrosionCorrosion models. This study is expected to serve as a guide for the production and industrial application of the refractoryRefractory materials.

Al2O3–MnO–SiO2Al2O3–MnO–SiO2 is an important base system related to steelmaking, ferromanganeseFerromanganese and silicomanganese production, and lithium ion battery treatment. Phase equilibriaPhase equilibria in this system have been extensively and repeatedly studied since 1943 due to significant discrepancies. The early experimental studies were carried out under nitrogenNitrogen gas flow which was considered as inert atmosphere. Recent studies showed that nitrogenNitrogen can dissolve into the oxide melts under reducing conditions causing different liquidus temperatures and phase compositions. Clearly, the experimental conditions and results have to be identified to be N-containing or N-free for various applications. Careful experiments and comparison of experimental techniques explained the discrepancies in this system reported by different researchers. ThermodynamicThermodynamic modelingModeling calculations are also performed for the N-containing and N-free systems to demonstrate the importance in the selection of the parameters.

Thermodynamic analysisThermodynamic analysis of chlorinationChlorination of zinc-bearing phases in pyrite cinder was conducted by FactSageFactSage thermochemical software. The effects of temperatureTemperature and main components of pyrite cinder on the chlorinationChlorination of ZnO and ZnFe2O4Zinc ferrite were studied. The results show that the presence of CaO and MgOMgO has no effect on the chlorinationChlorination of ZnO while the starting chlorinationChlorination temperatures of ZnO decrease from 1525 °C to 1200, 950, 850 °C with the presence of Fe2O3, SiO2, and Al2O3, respectively. In contrast, the presence of Fe2O3 and MgOMgO has no effect on the chlorinationChlorination of ZnFe2O4 while the starting chlorinationChlorination temperatures of ZnFe2O4 change from 1350 °C to 825, 1075, 1525 °C with the presence of SiO2, Al2O3, and CaO, respectively. The thermodynamic analysisThermodynamic analysis is consistent with the experimental results available in the literature.

Based on the problem of the heightHeight and angleAngle of the burnerBurner setting of a rotary furnace in a steelSteel plant, the three-dimensional model was built using ANSYS software to simulate the influence of the burnerBurner on the temperatureTemperature field and flow fieldFlow field in the rotary hearth furnaceRotary hearth furnace at different heights and different inclination angles. The results show that the lower the heightHeight of the burnerBurner , the more uneven the temperatureTemperature distribution near the carbon-containing pelletPellet layer and the lower the temperatureTemperature ; the inclination angleAngle of the burnerBurner is too small, which will cause the temperatureTemperature near the layer to be too high; large, will cause the flow fieldFlow field near the material layer to be disordered, which is not conducive to the reductionReduction reaction. By comparing the simulation results, a reasonable arrangement heightHeight and angleAngle are obtained to provide reliable data for the production of the rotary hearth furnaceRotary hearth furnace .

A simple method for calculating thermodynamicThermodynamic properties such as enthalpy, entropyEntropy, and molar heat capacityMolar heat capacity of sodium magnesium silicatesSodium magnesium silicates from their constituent polyhedra is introduced in this work. If it is assumed that the complex silicates are made up of different polyhedron constituents, the thermodynamicThermodynamic properties of complex compounds can be calculated from the linear combination of their polyhedron constituents. ThermodynamicThermodynamic properties of 18 polyhedra were obtained by weighted multiple linear regression analysis based on thermodynamicThermodynamic properties of 48 silicates compounds, which were collected from FactSageFactSage database. Standard enthalpy, entropyEntropy, Gibbs free energy, and molar hear capacity for the formation of five different sodium magnesium silicates (Na2MgSiO4, Na2Mg2Si2O7, Na4Mg2Si3O10, Na2MgSi4O10, Na2Mg2Si6O15) provide the foundation for evaluating the possibilities and priorities of reactions involving these compounds.

In this paper, the influence of distributorDistributor structure on the flow uniformity of molten steelSteel in the twin-roll thin strip continuous casting pool with 900 mm roll diameter and 1800 mm roll width is studied by numerical simulationNumerical simulation. The effects of the length of distributorDistributor, the number of side holes, and the arrangement of side holes on the fluctuation of molten pool level and the mixingMixing of molten steelSteel in the upper part of molten pool are studied. The optimal structure of the distributorDistributor is analyzed and obtained. The research results can provide theoretical guidance for the design of twin-roll strip distributorDistributor in practical production.

The experiments were carried out to determine the transient behavior of the inclusionInclusion in Si-deoxidized stainless steelSi-deoxidized stainless steel for high-grade plate. The samples were taken from three heats of the steelSteel during the whole production process from the AOD to the mold, which were subsequently examined by an automatic scanning electron microscope with field energy dispersive spectrometer (FE-SEM and EDS). It can be summarized that appropriate calcium treatment intensity could modify inclusionsInclusions into liquid ones. Excessive calcium treatment above ([Ca] = 25 ppm) will increase the melting point of the inclusionsInclusions, which cannot keep in the liquid region at the solidificationSolidification temperatureTemperature. Therefore, the calcium addition in Si-deoxidized stainless steel should be controlled to a relatively lower value ([Ca] = 10 ppm). In addition, the content of aluminum in steelSteel also has an important influence on the control of inclusionInclusion. When the content of aluminum ([Al] = 0.012%) is too high, the inclusionsInclusions in steelSteel are difficult to be controlled within the liquid phase. The chemical evolution of the inclusionsInclusions in steelSteel at high temperatureTemperature and during solidificationSolidification process were comprehensively calculated, considering all types of inclusionsInclusions such as calcium oxide, aluminum oxide, silicon oxide, calcium aluminate, calcium silicate, mullite, and liquid inclusionInclusion. The thermodynamicThermodynamic calculations are in good agreement with experimental results, which can predict the formation of the inclusionsInclusions in Si-deoxidized stainless steels.

Calcium treatment is an important method to reduce nozzle clogging and modify inclusionsInclusions in steelSteel . However, the problems of the low yield and stability of Ca in the molten steelSteel , and the low accuracy of the modification inclusionsInclusions caused by the experiential calcium addition are always a key issue of the calcium treatment for high-quality steels. The current modelingModeling of Precise Calcium TreatmentPrecise Calcium Treatment was built according to the laboratory experiment, theoretical calculation, and plant trial. Compared with the traditional method, the modelingModeling first built a database based on the actual molten steelSteel composition. Considering the different operating parameters in the plant, the calculation results of the suitable calcium wire were returned in time. The software was mainly composed of four parts: input of steelSteel composition, calculation result, operation parameter, and function selection. The current modelingModeling can save costs, improve efficiency, and give precise guiding suggestions.

In order to better study the application of CO2 in the vanadium extractionVanadium extraction process of a combined blowingCombined blowing converter, the simulation experiment of combined injection was carried out under laboratory conditions by changing the injection ratioInjection Ratio of CO2 and O2 at the initial injection temperatureTemperature of 1:10, 2:10 and 3:10 (the flow rate of O2 is 600 ml/min and the flow rate of CO2 varies proportionally according to the flow rate of O2). The oxidation of carbon and vanadiumVanadium in the molten pool and the thermal effectThermal Effect of molten pool under different bottom blowing flow ratesFlow Rates were studied. The experimental result shows that with the increase of bottom blowing strength, vanadiumVanadium -extraction and carbon conservation can be improved. If the flow rate of CO2 increases by 10%, the temperatureTemperature of molten pool decreases by about 5–7 °C and the heat from molten pool decreases by about 1.3857–2.0214 kJ.

Ampere Scientific has previously developed and provided industrial validation of the VARmetricTM measurement system to measure the location of electric arcs during vacuum arc remeltingVacuum Arc Remelting (VAR) of high temperatureTemperature specialty alloys. With the advent of VARmetricTM, it is now possible to continuously monitor and control arc distributions in order to tailor the heat fluxFlux that drives solidificationSolidification during the VAR process. Laboratory experiments have applied transverse magnetic fields to generate specified Lorentz forces as a control mechanism across the arc gap in order to drive arc locations to predetermined distributions. This type of control makes it possible to react to undesirable arc conditions during VAR operations or to provide a continuous control to specify a thermal profile for heat input to the melt pool necessary for ensuring defect-free ingots.

Tungsten is extraordinarily important for a broad range of industrial processes. It has the highest melting point of all metals (3410 °C) and a high density of 19.3 g/cm3. Tungsten carbide is known as one of the hardest materials. Tungsten is economically extractable from the two minerals wolframite ((Fe,Mn)WO4) and scheelite (CaWO4) through the intermediate ammonium paratungstate (APT). Tungsten concentrates are usually digested either by concentrated NaOH solution or by soda to form sodium tungstate solution which is further converted to APT. The leachingLeaching residue (tungsten slagTungsten slag) separated from the sodium tungstate solution consists of significant valuable metals such as W, Mo, Cu, SnSn, Mn and Fe. These metals can be efficiently recovered by high temperatureTemperature process with optimum conditions. Experimental work and thermodynamicThermodynamic calculations confirmed that most of the valuable metals can be concentrated to a low-melting point alloyAlloy and the clean slagSlag can be used for cement additivesAdditives.

FayaliteFayalite is one of the major components in many metallurgical slagsMetallurgical slags , such as copperCopper slagSlag and nickelNickel slagSlag , which contains higher ironIron grade than that in minable iron oresIron ores . It is believed that the carbothermal reductionCarbothermal reduction process at high temperatureTemperature is an effective way to reutilize fayaliteFayalite -bearing slags. In this paper, the non-isothermal reduction kineticsReduction kinetics of fayaliteFayalite were conducted using a thermogravimetric differential thermal analyzer heated to 1400 °C with different heating rates. The methods of Flynn-Wall-Ozawa and Málek were adapted to handle the kinetic data. The results show that the activation energyActivation energy increases until the conversion rate is 50% due to the deterioration of kinetic conditions, and then decreases. The average activation energyActivation energy is 514.20 kJ/mol. When the conversion rate is lower than 50%, the reaction model is the secondary chemical reaction model with the integral form of (1−α)2. Subsequently, with the conversion rate increasing, the model changes to the uniform growth of one-dimensional nucleation with the integral form of lnα.

MINTEK in South Africa is investigating the effect of preheating on smelter operations mainly to reduce the electrical energy requirement for smelters.Steenkamp, Joalet Dalene A pilot-scalePilot-scale facility is being developed which includes a one t/h rotary kilnRotary kiln coupled to an electric arc furnaceElectric arc furnace (EAF) (EAF) optionally served by either an alternating currentAlternating current (AC) (AC) or direct currentDirect current (DC) (DC) power supply.Denton, Glen Michael The facility also includes integrated materials handling, product handling, and water-cooling systems. It allows for the evaluation of cold versus hot feed (up to 900 °C) on smelter operations over periods of 2–3 weeks continuous operation.Pieters, Tertius The first application will study the effect of preheating on the smelting of titaniferous magnetite (15% TiO2) using a DCDirect current (DC)-furnace as part of the TiMag project. The second application will evaluate the effect of preheating on the production of high carbonHigh carbon ferromanganeseFerromanganese (targeting 78%Mn) using an AC-furnace as part of the PreMa project. The paper presents the results of the basic engineering of the project.

Molten blast furnaceBlast furnace (BF) slagSlag is a kind of liquid resource with abundant waste heat which has not been recycled in the ironIron and steelSteel industry. At present, the treatment of blast furnaceBlast furnace slagSlag is usually water quenching and air cooling accumulation. But, there are some disadvantages in this way to the treatment of blast furnaceBlast furnace slagSlag , such as serious air pollution and high water consumption. This paper describes the preparation of expanded slagSlag ball with blast furnaceBlast furnace slagSlag by rotary cupRotary cup . The effects of rotating speed, diameter of rotary cupRotary cup and water content on particle size distribution, vitreous contentVitreous content , and grind abilityGrind ability of slagSlag ball were studied. The blast furnaceBlast furnace slagSlag ball produced by this method is capable of self-drying because of its own heat. It does not need follow-up dehydration, drying, and other processes to save energy.

Cold heading process has been applied in the production of gear to improve production efficiency and reduce energy and steelSteel consumption. To increase the ductility of FAS3420H steelSteel and solve the cracking problem during cold heading, the Ostwald ripening behaviorOstwald ripening behavior of carbidesCarbides in steelSteel was studied during different annealing processes. Intercritical annealing process not only reduces the formation of spheroidal carbidesCarbides , but also causes pearlite to become coarser and larger, deteriorating the cold heading performance of the steelSteel . After 850 °C normalizing and 705 °C subcritical annealingSubcritical annealing , the lamellar pearlite in the sample was almost dissolved and a large number of small, evenly dispersed spherical carbidesCarbides formed, meeting the requirements of cold heading. In addition, a formula was presented to quantitatively characterize the progress of Ostwald ripening of the carbidesCarbides and the spheroidization mechanism of carbidesCarbides was analyzed from the perspective of kinetics and the experimental results.

In this paper, the converter steelmaking process is studied using numerical simulations and hydraulic modelHydraulic model experiments, in order to examine the influence of the angleAngle between the bottom blowing elements and the gas flow rate, on the flow characteristics of the molten pool. A 300t converter300t converter is used. The results demonstrated that the mixingMixing time and velocity field distribution, of the molten pool, changed with the angleAngle between the bottom blowing nozzles. Increasing the bottom blowing gas flow rate improved the dynamic conditions of the bath, accelerating the mass transfer process and reducing the volume fraction of the dead zone. Two arrangements with angles of 90° and 105° were applied to two furnace regimes. The industrial experiments showed that a large angleAngle between the nozzles was favorable because it accelerated the decarburization and dephosphorization. This reduced the endpoint carbon–oxygen equilibrium of molten steelSteel and reduced the content of iron oxide and TFe in the endpoint slagSlag.

Ferronickel slagFerronickel slag is a hazardous industrial waste containing a relatively high amount of chromiumChromium , which poses a great potential threat to the environment. It is of great significance to recover chromiumChromium from the slagSlag for both economic and environmental benefits. In this study, recoveryRecovery of chromiumChromium from ferronickel slagFerronickel slag via alkaline roastingAlkaline roasting followed by water leachingWater leaching was investigated, with an emphasis on the effect of roasting atmosphereRoasting atmosphere on the phase transformation of ferronickel slagFerronickel slag during the alkaline roastingAlkaline roasting process.

In this paper, vacuum distillationVacuum distillation technology was developed to purify crude seleniumSelenium produced by the hydrometallurgical seleniumSelenium removal treatment of copper anode slimeCopper anode slime and recover gold and silverSilver. Theoretical analysis of the saturated vapor pressure was performed to determine the feasibility of vacuum distillationVacuum distillation. Laboratory and semi-industrial experiments were carried out to determine the optimum process parameters. The kilogram-scale experiments showed that the purity of seleniumSelenium can be increased from 91.35 to 98.91% under the conditions of 50 Pa, 693 K, and 90 min. It is difficult to separate seleniumSelenium and tellurium completely by vacuum distillationVacuum distillation. The semi-industrial experiments showed that when the feed mass was 100 kg, under the conditions of 50 Pa, 693 K, and 160 min, the daily output of refined seleniumSelenium was more than 350 kg, the comprehensive power consumption for producing refined seleniumSelenium (per ton) was 587 kW h, the direct yield of Se was 96.78%, and the direct yields of Au and Ag were 99.72% and 99.56%, respectively, representing enrichment by more than 20 times. The process is an environmentally friendly and efficient metallurgical cleaning processCleaning process in the treatment of crude seleniumSelenium.

For the efficient recoveryRecovery of Ti from Ti-bearing blast furnace slagTi-bearing blast furnace slag, an innovative method was proposed in this paper by investigating the effect of P2O5P2O5 on the recoveryRecovery of Ti by super-gravity. Firstly, the precipitationPrecipitation behaviors of rutileRutile in Ti-bearing blast furnace slagTi-bearing blast furnace slag with different P2O5P2O5 content were investigated. The mineral compositions and microstructureMicrostructure of rutileRutile precipitated from various slags with different P2O5P2O5 content were analyzed through XRD and SEM-EDS methods, which presented that the P2O5P2O5 in slagSlag could effectively enrich Ti element through promoting the nucleation and growth of rutileRutile. As the P2O5P2O5 content in slagSlag increased from 0 to 3 wt%, the volume fractions and equivalent diameters of rutileRutile increased from 2.64% to 25.25% and 19.75 μm to 61.9 μm, respectively. Subsequently, the separation of rutileRutile from the slagSlag was conducted in a super-gravity field. After super-gravity separationSupergravity separation with G = 800 at 1310 °C for 5 min, the slagSlag melt went through the filter and entire high-purity rutileRutile was intercepted by the filter and effectively recovered from Ti-bearing blast furnace slagTi-bearing blast furnace slag.

Red mudRed mud is a waste material of the Bayer process for alumina production from bauxite ore. Red mudRed mud is generally pumped to disposal in an artificial pond which is accompanied by great land occupation and environmental issues. Many researches in different fields have been carried out to evaluate the red mudRed mud . Of these, researches on recovering valuable metals from red mudRed mud are the most successful. In this study, recoveryRecovery of ironIron , which is the most abundant metal in red mudRed mud , was investigated. A red mudRed mud sample with 34% Fe2O3 was used. Solid state carbothermic reductionCarbothermic reduction followed by wet magnetic separationMagnetic separation was performed to recover ironIron . ReductionReduction was carried out at temperatures 1000–1200 °C. Reduced samples were ground and subjected to wet magnetic separation.Magnetic Separation. The effect of reductionReduction temperatureTemperature and grindingGrinding time were investigated on the metallization of ironIron and the ironIron content of the final concentrate.

Electric arc furnaceElectric arc furnace (EAF) (EAFElectric arc furnace (EAF) ) dust is an important secondary resource from which valuable elements can be recovered. The recovery process can be intensified by the self-reductionSelf-reduction of core-shell EAFElectric arc furnace (EAF) dustEAF dust -biochar Biochar composite pellets under microwaveMicrowave irradiation. In this study, the effects of various parameters on reductionReduction of the core-shell EAFElectric arc furnace (EAF) dustEAF dust -biochar Biochar composite pellets in N2 were explored. It was demonstrated that under the optimal conditions of reductionReduction temperatureTemperature of 1050 °C, dwell time of 20 min, total C/Fe mass ratioMass ratio of 0.24, C/Fe mass ratioMass ratio of pelletPellet core of 0.30, and diameter of pelletPellet core of 6–8 mm, the resulting metallized pelletsMetallized pellets had total ironIron content of 70.13 wt %, ironIron metallization degree of 97.97%, volatilization percentage of zinc of 99.52%, volatilization percentage of lead of 98.49%, manganese content of 2.83 wt % and chromiumChromium content of 0.22 wt %. The great reductionReduction performance was attributed to strong gasificationGasification of carbon in association with selective distributionSelective distribution of biocharBiochar in the composite pellets with good microwaveMicrowave absorption.

A new process is proposed for recovering copperCopper from smelting slagSlag using waste cooking oil as a green reductant. More than 70% of waste cooking oil pyrolysisPyrolysis products is hydrogenHydrogen . In this study, a 70% H2-30% N2 gas mixture was used to simulate pyrolysisPyrolysis products for copperCopper slagSlag reductionReduction experiments. The equilibrium composition, oxygen potential, reductionReduction degree of Fe3O4 and the content of copperCopper dissolved in the slagSlag were calculated using FactSageFactSage software. The experimental results show that the Fe3O4 in the slagSlag is reduced from 12.9 to 2.9%, and the copperCopper from 17.82 to 0.53%. The unrecovered copperCopper is mainly dissolved in the slagSlag .

A large number of studies of vanadium extractionVanadium extraction based on sodium roastingSodium roasting experiments have been carried out in the laboratory through the self-designed converter vanadium extractionVanadium extraction device. The content of the main elements was analyzed by X-ray fluorescence spectrometer. The optimal conditions of roasting process of vanadium slagVanadium slag were obtained as follows: addition of 19% Na2CO3, roasting temperatureTemperature of 800 °C, roasting time of 120 min, and the particle size of vanadium slagVanadium slag was less than 125um. While the leachingLeaching process was conducted by water and the optimal conditions were obtained as follows: the leachingLeaching temperatureTemperature of 90 °C, leachingLeaching time of 30 min, and the liquid–solid ratio of 8.0 mL/g. Under those optimal conditions, the leachingLeaching efficiency of vanadiumVanadium was greater than 89.4%. And the enlarged experiments confirmed the stability of those parameters.

In this study, a novel process is proposed to produce titanium slagTitanium slag from Panzhihua ilmenite concentrateIlmenite concentrate. The carbothermic reductionCarbothermic reduction of ilmenite concentrateIlmenite concentrate, followed by wet magnetic separationMagnetic separation, was performed to generate metallic ironIron and a titanium-rich slagSlag in the presence of sodium sulfate and sodium carbonate. This work investigated the influence of reaction time, sodium sulfate additive, and sodium carbonate additive on the metallization, the TiO2 grade in the non-magnetic fractions, and recoveryRecovery of titanium dioxide. The results show that sodium carbonate increases the metallization, while sodium sulfate decreases the metallization of the reduced sample. In the presence of sodium carbonate, the highest metallization and recoveryRecovery of titanium dioxide can reach up to 90.57% and 0.83, respectively. In addition, the mechanism of additivesAdditives influence on the reductionReduction process is also discussed.

Experiments with different lanthanum (La) addition were carried out to investigate the component, size and distribution of inclusions and the change of microstructure in C-Mn steel treated by Ti-Mg-Ca. The samples exacted from the experimental steels were analyzed by scanning electron microscope (SEM), energy dispersive spectrometer (EDS), and optical microscope (OM). The results showed that inclusionsInclusions in steelSteel changed from MgOMgO –Al2O3, CaO+TixOy, and MnS to La2O2S, LaAlO3, and MnS after adding La. The content of La2O2S gradually increased, while the content of LaAlO3 and MnS in the composite inclusionsInclusions decreased with the increase of La content. In addition, the amount of inclusions increased first and then decreased with increasing La content. The size of effective inclusions was mainly less than 3 μm in different samples. The distribution of inclusions was dispersive and more acicular ferrite (AF) were obtained when the content of La was in the range of 0.011–0.025 wt%.

As the three-level management system for material consumptionMaterial consumption in the EAFElectric arc furnace (EAF) steelmakingEAF steelmaking plant cannot obtain statistics and carry calculation of material consumptionMaterial consumption for each furnace, the data from the system cannot provide guidance for actual smelting operation. In this paper, the field PLC process smelting data of the material consumptionMaterial consumption in “EAFElectric arc furnace (EAF) -LF-CC” process were collected from Kepware as OPC Server and by VS2010 as development tool. Then, they were classified (in categories of scrap charging, auxiliary materials, gas consumption, injection information, power supply data, etc.) and stored into Microsoft SQL Server 2008 database to build a database of furnace material consumptionMaterial consumption . The database construction provides guidance for reducing the material consumptionMaterial consumption and optimizing smelting operation for each furnace.

Non-blast furnaceBlast furnace ironmaking technology of metallurgical slagsMetallurgical slags with high-grade ironIron and low gradeLow-grade ironIron ore is of great importance and becoming increasingly valued. This paper presents a new type of continuous smelting reductive reaction for non-blast furnaceBlast furnace ironmaking technology. Cold water model experiment based on principle of similitude establishes a new type of reactor. This paper studies the core problem of two-phase separation and investigates the relationship among material factors, operating factors, equipment factors. Finally, according to the analysis of theoretical and experimental data, we can obtain the empirical equation between the oil phase entrainmentOil phase entrainment and each factor, in order to provide a theoretical basis for further thermal experiments and has certain reference value.

It is a feasible method to improve the quality of steelSteel products by adding rare earth to change the state of arsenic in steelSteel to avoid its harm. In this study, the As-bearingAs-bearing inclusions, The rare earth inclusionsInclusions in steelSteel were extracted by non-aqueous electrolysisElectrolysis method, and their types were fully understood. Wagner activity model and non-equilibrium solidificationSolidification model were used to calculate the formation process of rare earth inclusionsInclusions in liquid and solidificationSolidification process. The formation mechanism of single-phase and complex As-bearingAs-bearing inclusions, The rare earth inclusionsInclusions was verified by laboratory experiments. The results showed that La2O3 and La2O2S were formed in the liquid phase, then the As-bearingAs-bearing inclusions, The rare earth inclusionsInclusions La–S–As and La–As began to form during the solidificationSolidification process of steelSteel liquid. The composite inclusionsInclusions of La–O–S–As with distinct stratification were further precipitated.

The phosphorus content of the hot metal is higher than the range and optimal content of hot metal normally used for steel makingSteel making in LD converters at EISCO. Therefore, adequate care is necessary to investigate slagSlag /metal partition of phosphorus. The activity of total ferrous oxide in the slagSlag was estimated according to the model of regular ionic solutions, it was used to find the concentration of oxygen in the metal. The activity coefficient of phosphorus and oxygen in the metal is 1.1195 and 0.8367, respectively. By using the phosphate capacityPhosphate Capacity , phosphorus distributionPhosphorus Distribution between slagSlag and metal could be calculated; the effect of temperatureTemperature on both phosphate capacityPhosphate Capacity and phosphorus distributionPhosphorus Distribution ratio is large, while the influence of slagSlag composition is small.

Red mudRed mud or bauxite residue can be regarded as a by-product of aluminum extraction process since it contains a significant amount of ironIron and some valuable elements. Therefore, the treatment of red mudRed mud has been a hot topic for some decades. Last year, the authors started a laboratory-scale project dealing with stepwise recoveryRecovery of valuable elements from red mudRed mud of Seydisehir Aluminum Plant, Turkey. The first step is related to the recoveryRecovery of ironIron and pyrometallurgical methods (solid-state reductionSolid-state reduction and smelting) are currently being performed. Nonferrous metals will then be selectively leached in the second step. In TMS 2019, the authors outlined the literature related to the smelting studies for iron recoveryIron recovery from bauxite residue. In the extent of the present work, a literature review relevant to the solid-state reductionSolid-state reduction studies for recoveryRecovery of ironIron from red mudRed mud was presented.

This study focuses on the recycling of scandium from high-temperatureTemperature processing metallurgical slagsMetallurgical slags through pyrometallurgical routes. For the optimization of the rare earth (scandium) recycling route, the distribution of scandium inCaO–Al2O3–Sc2O3 CaO–Al2O3–Sc2O3 slagSlag system is worth investigation, and the precipitationPrecipitation behavior of scandium in CaO–Al2O3–Sc2O3CaO–Al2O3–Sc2O3 slagSlag system during slagSlag cooling progress is of significance. In this work, the precipitationPrecipitation and solidificationSolidification behaviors were recorded by a confocal scanning laser microscope (CSLM) combined with an infrared imaging furnace heating (IIF). The compositions and microstructures of the equilibrated phases of these systems were determined by an electron probe microanalyzer with standardized wavelength dispersive spectroscopy (EPMAEPMA /WDS). It is observed that there is a remarkable influence of B2O3 addition on the precipitationPrecipitation and solidificationSolidification behaviors in the CaO–Al2O3–Sc2O3CaO–Al2O3–Sc2O3 system. By choosing different cooling rates (20, 50, and 100 K/min) the CCT diagram was constructed, which can be employed to guide the rare earth recoveryRecovery in industrial practice.

With the recycling of scrap steelSteel , the accumulation of SnSn deteriorates the properties of high-strength low-alloyAlloy structural steelSteel . The effect of intercritical heat treatmentIntercritical heat treatment (IHT) on microstructureMicrostructure and the mechanical propertiesMechanical properties of SnSn bearing 33MnCrB5 steelSteel has been studied. Results indicated that a composite microstructureMicrostructure of ferrite and martensite was obtained by adding the intercritical quenching to the conventional quenching and tempering. Compared with the conventional heat-treated samples, the impact energy increased evidently from 30 J to 77 J and the strength decreased slightly. The loss of strength resulting from the IHT is reduced by the modification of tempering conditions. Furthermore, AES showed that the grain boundary segregationGrain boundary segregation of SnSn can be alleviated via the IHT. Based on different heat treatment results, the optimum heat treatment technology, that is, 910 °C normalizing, 860 °C pre-quenching, 770 °C intercritical quenching, 450 °C tempering, was obtained to balance the strength and toughness.

A novel way of producing a cobalt–nickelNickel–ironIron alloyAlloy containing 55% Co, 9% Ni, and 36% Fe from an oxide ore with 1.8% copperCopper, 0.26% cobalt, 2.8% ironIron, and 0.08% nickelNickel has been established. The ore is initially treated hydrometallurgically via leachingLeaching and precipitationPrecipitation steps to upgrade copperCopper, cobalt, ironIron, and nickelNickel as a bulk sulphide concentrate. PrecipitationPrecipitation is carefully carried out to lower down ironIron in the bulk sulphide concentrates. The sulphide concentrate is smelted at 1,220 °C to produce blister copperCopper and slagSlag containing 11% Co, 1.8% Ni, and 7.2% Fe. The effects of basic and acidic fluxes in promoting good metal/slagSlag separation were studied. The slagSlag is then smelted under reducing environment at 1,400 °C to yield cobalt–nickelNickel–ironIron alloyAlloy. There is a broad agreement between thermodynamicThermodynamic prediction and experimental results. The alloyAlloy was characterised using scanning electron microscopy (SEM) technique.

The inevitable particle segregationParticle segregation behaviors of granular materials are undesirable in the industrial processes. It will directly affect the heat transfer efficiency between gas and solid phases during the ironmaking process of blast furnaceBlast furnace. Therefore, the understanding and prediction on the particle segregationParticle segregation behaviors are vital to optimize the process and improve the production efficiency. This work first employs the Discrete Element MethodDiscrete element method (DEM) to investigate the effects of the parameters, such as the particle density, the mean diameter, the mass of particles, the particles mass ratioMass ratio, and the angleAngle of chute, on the mass segregationSegregation and size segregationSegregation behaviors at the bell-less topBell-less top blast furnaceBlast furnace with the serial type hopper. Then, the Artificial Neural NetworkArtificial neural network (ANN) model is proposed to predict the aforementioned behaviors in the radial direction based on the numerical data. The results show that the predicted segregationSegregation behaviors by the established ANN model are in a good agreement with the simulated results.

Li4SiO4 is a promising material for CO2 capture at high temperatures. A high capture capacity up to 36.7 wt% between 450 and 700 °C, fast carbonation/decarbonation kinetics, good mechanical propertiesMechanical properties, and also cyclic usage can be counted as the advantages of this solid. Li4SiO4 can be synthesized using different methods: the solid-state reaction, the precipitationPrecipitation method, the impregnation suspension method, and the sol–gel method. However, all the processes which are mentioned above requires high energy consumption and result in products having a large grain size. Combustion synthesisSynthesis techniques are energy-efficient and advantageous in terms of obtaining nano-sized ceramic powders. Therefore, the main purpose of this study is producing Li4SiO4 powders with volume combustion synthesisVolume combustion synthesis (VCS) available to use as a high temperatureTemperature sorbent in CO2 capture, instead of the conventional and commercial methods.

Blast furnaceBlast furnace dust and electric arc furnaceElectric arc furnace (EAF) dustEAF dust are two typical solid wastes in ironIron and steelSteel industry. In order to overcome the shortcomings of traditional processes, such as low metal recoveryRecovery efficiency and high secondary pollution, microwaveMicrowave energy was applied in this study to intensify the self-reductionSelf-reduction of core-shell BF dustBF dust-EAFElectric arc furnace (EAF) dustEAF dust composite pellets based on impedance matchingImpedance matching for realizing highly efficient migration and separation of ironIron, zinc, and lead. By reducing the composite pellets in microwaveMicrowave field, it was found that under the optimal conditions of proportion of EAFElectric arc furnace (EAF) dustEAF dust in shell to all EAFElectric arc furnace (EAF) dustEAF dust in the pelletPellet of 20%, reductionReduction temperatureTemperature of 1000 °C, and dwell time of 15 min, metallized pelletsMetallized pellets with the total ironIron content of 68.73 wt %, ironIron metallization degree of 95.87%, zinc removal percentage of 88.78%, lead removal percentage of 94.38%, and compressive strength of 190.4 N/p were obtained.

Tundish with induction heatingTundish with channel type induction heating appliance has been attracting more and more attention in steelmaking process in recent years. The double induction heater will occupy a large tundish capacity, which consequently decreases the output of steelSteel plant. A single-induction heater tundish technology has been put forward in the present work. Its flow characteristic is studied by water modelling with considering both non-isothermal and isothermal service situations and compared with that of double induction heater. The results show that the flowing consistency between different strands is a bit weaker with single-induction heater than with double induction heater. Despite this, the optimized case can completely meet the industrial requirement with its dead volume fraction 15% and the minimum break time 92 s.

The strength, ductility, and cutting performance can be seriously affected by the size and distribution of inclusionsInclusions in the steelSteel . Using a high-temperatureTemperature tube electric resistance furnace, the effect of Mg addition on the evolution of inclusionsInclusions in 16MnCrS5 steelSteel was investigated. Besides, the deformation behavior of inclusionsInclusions was carried out by a simulated testing rolling mill (Gleeble-3500). The results showed that the ratio of compound inclusionsInclusions (MgOMgO ·Al2O3 wrapped by MnS) increased after Mg addition in steelSteel , and the same trend was obtained in the aspect ratio of inclusionInclusion together with the ability of resisting the deformation of inclusionsInclusions after hot-extruding. With the increasing of Mg addition from 8 ppm to 42 ppm, the mean area of inclusionsInclusions in experimental ingots first decreased and then increased. Additionally, the peak mean area of inclusionsInclusions occurred under the Mg content of 35 ppm.

High-quality transition metal nitridesNitrides have been prepared by direct reductionReduction and nitridationNitridation of transition metal oxidesTransition metal oxides with ammoniaAmmonia as reductant and nitrogenNitrogen source. The thermodynamicsThermodynamics of reductionReduction and nitridationNitridation process was initially analyzed. Then, two kinds of nitridesNitrides prepared by the specified process were compared. The effects of reaction temperatureTemperature and reaction time on the product quality were investigated. It was found that the reaction temperatureTemperature and time had a significant effect on the reductionReduction and nitridationNitridation process. With the increase of reaction temperatureTemperature and time, the oxygen content was decreased in the product. This method avoids the introduction of other impurity elements except the negligible trace elements accompanied with the raw materials. In the meantime, the final product contains relatively high-nitrogenNitrogen content and low residual oxygen content. The quality of the products has been greatly improved and fully meets the standards of industrial products.

The liquid phase fluidity of iron oresIron ores reflects the effective bonding range in the binder phase. It is usually evaluated by a liquid fluidityLiquid fluidity index, which increases with the liquid amount and decreases with the liquid viscosityViscosity . The liquid fluidityLiquid fluidity index compares the area growth rate of ironIron ore sample before and after melting. Other parameters such as the liquid flowing timeLiquid flowing time also have an important impact on the liquid phase fluidity. The composite liquid fluidity indexComposite liquid fluidity index is proposed to characterize liquid phase fluidity of ironIron ore. The composite liquid fluidity indexComposite liquid fluidity index is calculated from area growth rate, initial melting temperatureTemperature , liquid flowing timeLiquid flowing time , heating rate and maximum temperatureTemperature . Compared with liquid fluidityLiquid fluidity index, the composite liquid fluidity indexComposite liquid fluidity index is better suited as a means to evaluate the liquid fluidityLiquid fluidity of iron oresIron ores and predict the liquid fluidityLiquid fluidity of ironIron ore by its chemical composition.

The existing sinteringSintering process is to add a certain proportion of water to the sinteringSintering raw materials such as ironIron ore powder, coke powder, and quicklime. After mixingMixing and pelletizing, the raw materials are sintered on the pallet train to cause a series of high temperatureTemperature physical and chemical changes. Existing sinteringSintering processes have high energy consumption and high pollution. In order to reduce energy consumption and pollution in the existing sinteringSintering process, it was developed as Magnetite carbon-freeCarbon-free Sintering sinteringSintering process based on electromagnetic inductionElectromagnetic induction. Compared with the existing sinteringSintering process, this new magnetite sinteringSintering process could achieve high thermal efficiency, with no coke added. It could reduce pollutant emissionEmission, e.g. COX, NOX, SOX. etc., decreasing energy consumption and return fines rate. In this study, we focus on the influences of ironIron powder’s addition amount, insulation time, insulation temperatureTemperature, and heating power on sinter, and we will evaluate its performances by using the mineral phase composition of sinter, XRD analysis, compressive strength, and other indicators. Moreover, we find that this new sinteringSintering process can achieve better metallurgical propertiesMetallurgical properties and mechanical strength.

Aiming at the problem of low efficiency in high bed sinteringSintering, a new process, namely double layer pre-sinteringDouble layer pre-sintering was developed by AISC IronIron and SteelSteel Research Institute. The new process can obviously improve the bed permeability and sinteringSintering productivity with a large proportion of fine ironIron concentrate. However, the cold strength of sinter for the new process decreases to a certain extent, which is mainly caused by the lack of oxygen in the lower sinteringSintering layer. At present, by properly prolonging the pre-sinteringSintering time, the oxygen deficiency in the lower sinteringSintering layer can be alleviated to a certain extent, and the cold strength of sinter can be significantly improved. The industrial test results of 360 m2 sinteringSintering machine in No. 2 sinteringSintering workshop and the No. 4 and No. 5 blast furnaces of IronIron-making Plant of Angang SteelSteel Co. Ltd for nearly 7 months show that the new double layer pre-sinteringDouble layer pre-sintering process is completely feasible in production practice, and 16.11% of the sinteringSintering output has been achieved. The blast furnaceBlast furnace runs smoothly with the sinter of double layer pre-sinteringDouble layer pre-sintering process. Furnace productivity, fuel ratio and air volume are basically consistent with the reference period. The implementation of this new process is the first case in China. However, the new process needs to be further improved in order to achieve the best sinteringSintering output, reduce sinter solid fuel consumption and emissionEmission of nitrogenNitrogen oxides and carbon oxides.

The ironmaking processes that directly use the raw materials of ironIron ore fines are expected to significantly reduce energy consumption, carbon dioxideCarbon dioxide emissionEmission and have great advantages in ironIron ore resource utilization. In this paper, the reductionReduction behavior of the in-flight fine hematite particles in CO and H2 mixture atmosphere is studied with a modified high-temperatureTemperature drop tube furnace. The kinetic mechanism of the gas-solid reductionReduction of hematite ore finesHematite ore fines is determined in the temperatureTemperature range of 1450 ~ 1550 K. The particle size is 53 ~ 64 μm and the reaction time is less than 2 s. The effect of carbon monoxideCarbon monoxide concentration in the gas mixture on the reaction rate is examined. Based on the kinetic analysis and the morphologyMorphology observation, the unreacted shrinking core model is used as the mathematical description for the reductionReduction mechanism. The reaction rate equation is obtained and the calculated results are in good agreement with the experimental ones.

For the uneven gas–solid distributionGas–solid distribution in the process of fluidized bedFluidized bed ironmaking, the effect of the distributorDistributor on gas–solid homogeneity in fluidized bedFluidized bed was investigated by using physical simulationPhysical simulation . Statistical analysis and spectral analysis were used to investigate the pressure fluctuations in the fluidized bedFluidized bed with the distributorDistributor of different perforated ratioPerforated ratio , and the results were verified by optical analysis. The results reveal that the smaller perforated ratioPerforated ratio of the distributorDistributor can reduce the bubble size of the whole bed and reduce the pressure fluctuationPressure fluctuation . Thus, the gas–solid dispersion is uniform, and the fluidization quality of the fluidized bedFluidized bed is improved. However, the distributorDistributor has a limited effect area, which has a great influence on the lower part of the fluidized bedFluidized bed . As the gas velocity and the heightHeight increase, the effect becomes weaker. Under the operating conditions of 100 L/min, the perforated ratioPerforated ratio of 0.91% can reduce the pressure drop of the entire bed by 65%. It can also reduce the pressure drop deviation in the lower part of the bed by more than 79%.

Sinter is the main ironIron-containing raw material for blast furnaces. As ironIron ore resources are gradually depleted, the types of raw materials for sinter are complicated, so their chemical composition often changes. At present, the common method for studying the sintering performanceSintering performance of ironIron ore is the sinteringSintering pot test. This method is cumbersome and needs a long process time, and it is impossible to recognize the rapid reaction change of the raw material. Therefore, a prediction modelPrediction model was established by building a sinteringSintering experimental database and using statistical analysis methods such as correlation, regression and sequence quadratic programmingSequence quadratic programming analysis to analyze the relationship between the chemical composition and the tumbler strength of sinter, so as to simplify the sinteringSintering blending technology. The regression coefficient of the model is 0.803, indicating that the model has good prediction potential for sinter strengthSinter strength.

Aiming at reductionReduction of carbon and nitrogenNitrogen oxides emissionEmission in Iron ore sinteringIron ore sintering process and increasing of sinteringSintering productivity, a new technology of double-layer pre-sinteringDouble-layer pre-sintering has been developed. The new technology is quite different from the conventional single-layer sinteringSintering and has been adopted in No. 2 sinteringSintering workshop of Anshan IronIron and SteelSteel Group Co. Ltd. During the industrial-scale pilot at a 360 m2 sinteringSintering machine for 26 weeks, the total emissionEmission of carbon and nitrogenNitrogen oxides was decreased by 45239.8 tons and 615.4 tons, respectively, the productivity of sinteringSintering machine increased from 450.6 to 523.2 t/h that is equal to a 16.11% increase of output. The blast furnaceBlast furnace used for the sinter produced through the new process is in good condition and a good economic and environmental result has been achieved.

The growth rate of ring formationRing formation increased when titanium-containing powder had been added into Shougang grate-kilnGrate-kiln to produce titanium-containing pellets, which had a strong impact on the production processes. In this article, the mechanism and influencing factors of the ring formationRing formation problem had been studied, based on sampling and analyzing samples from different parts of kiln. The result indicated that liquid phase of low-melting point and particles were the main reason of ring formationRing formation. The ring formationRing formation was difficult to clean up because its strength increased in the high-temperatureTemperature oxidability atmosphere. The desiccation and preheat of green-ball were degraded when the titanium-containing fines had been added. A large amount of powder and particles were produced in kiln because of the lower compressive strength of dry-ball, which led to the rapid growth of rings.

The ultrahigh-basicityBasicity (R = 1.75) mold fluxFlux has been proved to be effective in coordinating heat transfer and lubrication during continuous casting of peritectic steelSteel in industry, Properties of the mold fluxFlux may be further improved through the adjustment of the Li2OLi2O content in the fluxFlux . The effects of Li2OLi2O content on the properties of ultrahigh-basicity mold fluxUltrahigh-basicity mold flux were systematically investigated. With the increase of the Li2OLi2O content from 0.8 to 2.4%, the viscosityViscosity of the ultra-high basicityBasicity mold fluxFlux at the temperatureTemperature of 1573 K increased and then decreased, and the maximum viscosityViscosity was 0.148 Pa·s at the Li2OLi2O content of 2.0%. With the increase of the Li2OLi2O content from 0.8 to 2.4%, the break temperatureTemperature was reduced from 1484 to 1435 K, the initial crystallization temperatureTemperature , which was measured by an in-house apparatus, could decline by approximately 100 K with 2.4% Li2OLi2O addition while the crystallization rate represented an increasing trend except for the case with 2.0% Li2OLi2O . This study enhances the understanding of specified mold fluxFlux for peritectic steelSteel .

Commercial production of carbide materials is often associated with high energy costs due to the high temperatures and long milling times required to produce a powder carbide product. A process for synthesizing Mo2C was developed to reduce carburization temperatures and product particle size. Precursor material, produced by adsorbing molybdate anions onto activated carbon, was carburized under a reducing gas atmosphere to produce Mo2C at temperatures below 800 °C. MolybdenumMolybdenum adsorption was measured using inductively coupled plasma spectroscopy, and carburization products were characterized using X-ray diffraction and scanning electron microscopy. Response surface analyses were used to mathematically model the adsorption and carburization processes and to determine optimal parameters for Mo-loading and Mo2C synthesisSynthesis . The effects of temperatureTemperature , time, pH, and initial Mo concentration were used to model adsorption behavior while the carburization process was modelled using the effects of temperatureTemperature , reaction time, and reducing gas atmosphere on the synthesisSynthesis of Mo2C.

The effect of different refining slagSlag components on the cleanlinessCleanliness of 25Cr2Ni4MoV turbine rotor steelSteel was studied through four industrial experiments. It is found that less total oxygen, dissolved oxygen, inclusionInclusion quantity and smaller inclusionInclusion size could be obtained with a basicityBasicity of the refining slagSlag between 3 and 4 and a C/A ratio between 7 and 10. FactSageFactSage 7.0 was used to study the influence of slagSlag composition on dissolved oxygen in molten steelSteel and Al2O3 inclusionInclusion adsorption. The results reveal that high basicityBasicity is beneficial to reduce dissolved oxygen in molten steelSteel , and less Al2O3 inclusionsInclusions exist with high basicityBasicity and high C/A. Then, the evolution of typical inclusionsInclusions in the refining process was discussed. Next, the physicochemical parameters of refining slagSlag were analyzed, the viscosityViscosity and melting point of the four groups of refining slagSlag showed that the addition of SiO2 and Al2O3 in the slagSlag can reduce the amount of CaF2CaF2 . Finally, the influence of the composition of refining slagSlag on the lining erosion was investigated.

The end-point temperatureTemperature prediction modelPrediction model of molten steelSteel for RH refiningRh refining process, based on principal component analysisPrincipal component analysis (PCA) and case-based reasoningCase-based reasoning (CBR), was established for the precise control of end-point molten steel temperatureMolten steel temperature . Six principal components were selected from eleven factors influencing molten steel temperatureMolten steel temperature based on PCA, which were taken as the principal component analysisPrincipal component analysis and case-based reasoningCase-based reasoning (PCA-CBR) model inputs to construct the corresponding model. The precision of the model was verified by the actual production data of a steelSteel plant, which was compared with the prediction modelPrediction model based on conventional CBR model as well as the back propagation neural network (BPNN) model. The results show that the precision of the model based on PCA-CBR reaches 69.67%, 83.67%, and 97%, respectively, when its prediction error is in the range of [−5, 5], [−7, 7], and [−10, 10], respectively. Therefore, the model can predict the end-point temperatureTemperature of molten steelSteel for RH refiningRh refining process more precisely.

TheHigh-carbon Ferromanganese EU-funded PreMa project investigates the potential for a preheating stage to reduce the electrical energy requirement and CO$$_2$$ emissions produced, during the production of high-carbonHigh carbon ferromanganeseFerromanganese in a submerged arc furnace.Steenkamp, Joalet Dalene A pilot-scalePilot-scale campaign will be conducted at MINTEK in South Africa to demonstrate the potential effect of preheating on furnace operation. For the pilot-scalePilot-scale campaign, the design of the process flowsheet and sizing of the furnace and ancillary equipment were based on predictive mass and energy balance calculations. FactSageFactSage thermodynamicThermodynamic software and Microsoft Excel were utilised. The paper reports on the method applied and results obtained.

It is recently found that oxide inclusionsOxide inclusions played a significant effect on the microstructureMicrostructure and magnetic properties in low-aluminum non-oriented electrical steelsNon-oriented electrical steels . In the current study, inclusionsInclusions with different characteristics were generated through different production process. InclusionsInclusions were characterized using an automatic scanning electron microscope and thermodynamic analysisThermodynamic analysis was conducted using FactSageTM. It is observed that the deformation behavior of SiO2–Al2O3–MnO inclusionsInclusions was closely related to their composition. InclusionsInclusions forming during the solidificationSolidification process showed a smaller size and a higher fraction of SiO2, which was hardly deformed after rolling and had little pinning effect on the grain growth. On the contrast, large inclusionsInclusions had a lower fraction of SiO2 and were easily deformed after rolling process. From the view of improving the magnetic properties of non-oriented electrical steelsNon-oriented electrical steels , inclusionsInclusions should be controlled to be undeformed and larger composite SiO2–Al2O3–MnO inclusionsInclusions should be removed.

Bottom-blowing O2–CaO converters have been used in steelmaking plants for a long time owing to their superior metallurgical performanceMetallurgical performance . Furnace life has been known to restrict their wide application; however, this can be overcome by mixingMixing CO2 with a bottom-blowing gas to reduce the temperatureTemperature of the fire spot zone above the tuyere, thus prolonging the furnace life. In our study, a materials and heat balance model was established, and the effect of bottom-blowing O2–CaO mixed with CO2 was studied. Results showed that with increased CO2 in the gas mix, surplus heat decreased, and the amount of ore required was reduced. The optimal mixingMixing ratio for bottom-blown CO2 was 55.6%, at which point the fire spot zone temperatureFire spot zone temperature decreased by 795 °C and the ferrous charge consumption requirement decreased by 10.1 kg/t.

In order to optimize the bakingBaking of RH vesselRH vessel , numerical simulationNumerical simulation of gas flow, combustion and heat transfer in vacuum vessel during the bakingBaking process was conducted. The FLUENT code with finite volume and SIMPLEC methods was adopted to investigate the influence of top lance position on the temperatureTemperature distribution of RH vesselRH vessel . The numerical model was verified with the experimental data. Results show that the different heightHeight of RH top lance could cause significant changes of temperatureTemperature distribution in the vertical direction. There is an ideal and uniformity in temperatureTemperature distribution when the top lance heightHeight is 4.5 m, which is benefited for removing the remaining solid steelSteel in RH vesselRH vessel . When the heightHeight of top lance is 5 m, the bottom of the vacuum vessel and the immerge tube are in high bakingBaking temperatureTemperature . The two bakingBaking schemes could be used in combination in the production process to improve the bakingBaking effect.

Nickeliferous pyrrhotite (Pyrr) tailingsTailings represent a promising Ni resource. Previous work has demonstrated that heating of nickeliferous Pyrr in the presence of suitable additivesAdditives under a non-oxidizing atmosphere is capable of recovering the Ni value in the form of ferronickelFerronickel alloyAlloy . In this study, the Pyrr concentrate, a flotationFlotation product of nickeliferous Pyrr tailingsTailings , was thoroughly mixed with metallic Fe and activated carbon, and then pressed into briquettes. The resultant briquettes were heat-treated at 900 °C for varying periods of time in Ar, followed by an Ar-quenching operation to retain the high-temperatureTemperature structure. The calcine microstructureMicrostructure was examined as a function of treatment time, together with the composition of Ni-bearing phases. It was shown that progression of the ironIron sulfidization was companied by the formation of ferronickelFerronickel alloyAlloy via multiple mechanisms, and prolonged treatment time promoted the uniformity of phase compositions and coarseningCoarsening of the alloyAlloy particles.

The lack of knowledge regarding the mineralogical and metallurgical propertiesMetallurgical properties of Mn ores is a common problem in the production of ferromanganeseFerromanganese alloys. DecrepitationDecrepitation , which is the breakage of solid particles upon heating, is an important quality parameter of manganese oresManganese ores which has not been adequately studied. This work will study the effect of different parameters on the decrepitationDecrepitation index when the ores are preheated in a rotary kilnRotary kiln . These parameters are the rotational speed, heating rate, temperatureTemperature , and mineralogical composition. Three South African ores, two from the same mine, will be used for this study. The purpose of the paper is to report on method development.

A novel method to smelt high-carbon ferrochromiumHigh-carbon ferrochromium by synergistic reductionReduction with vanadium extractionVanadium extraction tailingsTailings with high content chromiumChromium and chromite is proposed in this paper, which can efficiently recoverRecover chromiumChromium and ironIron from vanadium extractionVanadium extraction tailingsTailings with high content chromiumChromium and produce high value-added products. The recoveries of chromiumChromium and ironIron reach 95.79% and 98.06%, respectively, and decrease with the increase of mass ratioMass ratio. The smelting timeSmelting time has little influence on the recoveries of chromiumChromium and ironIron. The recoveries of chromiumChromium and ironIron decreased with the increase of reductant amountReductant amount. The content of chromiumChromium and ironIron in the high-carbon ferrochromiumHigh-carbon ferrochromium is between 47.00% to 52.00%, and 35.00% to 60.00%, respectively. The contents of impurity elements in the high-carbon ferrochromiumHigh-carbon ferrochromium meet the expected requirements except nos. 7 and 8. The content of chromiumChromium reached 52.01% in the high-carbon ferrochromiumHigh-carbon ferrochromium. The optimum smelting conditions are mass ratioMass ratio at 5:1, smelting 10 min, and C/O at 1.

In blast furnaceBlast furnace smelting, MgOMgO can play a role in improving slagSlag performance. In the production process of pellets, the suitable MgOMgO content is easy to reduce the strength of pellets, but other metallurgical propertiesMetallurgical properties of pelletPellet can be improved. In this paper, dolomite is used as the main additive of MgOMgO , and the effects of 0, 1, 3, 8, and 11% different magnesium additive contents on the metallurgical performanceMetallurgical performance of pellets are studied. The results show that with the increase of magnesium additive, the drop strength of the green ball increases, and it increases to 8.3 times when the magnesium additive content is 1.5%. The compressive strength of the green ball first decreases and then rises. When the content is 1.5%, the highest value of 1.5N was reached. The strength of the finished ball gradually decreased to 1990N. The highest reductionReduction degree increased to 80%, and reductionReduction swelling index decreased 10.02%. Meanwhile, the softening and smelting properties of magnesium pellets are improved. The softening and smelting temperatureTemperature range of single magnesium pellets and mixed burden becomes narrow.

The properties and mineralizationMineralization behaviour of a heavy metal industrial sludgeIndustrial sludge with Cu and Ni content of 2.61 and 2.28% were investigated. The main phases of the sludge are calcium hydrophosphate, gypsum and amorphous hydroxide, silica gel. Heavy metals such as copperCopper and nickelNickel are dispersed in various physical phases, and the mixture of calcium hydrogenHydrogen phosphate is the main carrier of the valuable metals nickelNickel and copperCopper, which are difficult to be extracted by physical methods. MineralizationMineralization test results show that a concentrate with Cu content of 6.96% and Ni content of 6.15% can be obtained by flotationFlotation of the sintered product under these conditions: the dosages of bituminous, sodium sulfate, quartz and borax are 15%, 20%, 20% and 2% respectively, the sinteringSintering temperatureTemperature is 1150 °C, the sinteringSintering time is 60 min. The recoveries of copperCopper and nickelNickel in concentrate are 87.63% and 88.64%, respectively, and the Cu and Ni grade in tailing can reduce to 0.54% and 0.44%, respectively.

With a growing demand for high-grade pelletPellet feeds as well as a considerable increase in ore price, using cost-effective and high-grade sinter feeds for oxidized pellets production becomes more attractive. In this paper, one hematite concentrate from the wet grindingGrinding of a typical coarse sinter feedSinter feed (GSF#) was used as raw material for manufacturing oxidized pellets. The effect of GSF# proportion in ore mixture, up to 40 wt% on roasting and metallurgical propertiesMetallurgical properties of oxidized pellets was investigated. Moreover, the effects of binary basicityBasicity and MgOMgO content were also studied. The results show that in the case of natural basicityBasicity and MgOMgO content, increasing the proportion of GSF# improves high-temperatureTemperature softening–melting properties of oxidizing pellets, whereas imposes negative impacts on pelletPellet strength as well as reductionReduction swelling performance. The adverse effects can be eliminated by increasing binary basicityBasicity and MgOMgO content to produce Mg-bearing fluxed pellets, which indicates the feasibility of using high proportion of ground sinter feedSinter feed to manufacture high-quality oxidized pellets at low production cost.

The effects of smelting temperatureTemperature , slagSlag basicityBasicity and smelting timeSmelting time on the slagSlag -metal separation and slag phaseSlag phase after smelting-separationSmelting-separation for vanadiumVanadium titanomagnetiteTitanomagnetite metallized pelletsMetallized pellets were investigated in the present work. The results show that the increase of smelting temperatureTemperature could decrease the viscosityViscosity of molten slagSlag and promote slagSlag -metal separation. Meanwhile, the diffraction peaks intensity of magnesia-alumina spinel in slagSlag obviously increases. Within proper basicityBasicity range, increasing slagSlag basicityBasicity is conductive to decreasing the liquidus temperatureTemperature and viscosityViscosity of molten slagSlag , and accelerating the settling velocities of ironIron drops. However, further increasing slagSlag basicityBasicity to 1.0 would cause abundant generation of perovskite with high melting point in slagSlag . Appropriate extension of smelting timeSmelting time contributes to the coalescence and settlement of ironIron droplets, but excessive smelting timeSmelting time may lead to the formation of TiC in slagSlag , which is bad for the slagSlag -metal separation.

FerronickelFerronickel tailingsTailings , by-products from nickelnickel laterite direct reductionReduction -magnetic separationMagnetic separation process, are now stored up in large quantities with low utilization because of the high MgOMgO content. In this paper, ferronickel tailingFerronickel tailing with 5.82% Fe, 0.51% Ni, 44.08% SiO2, and 31.98% MgOMgO was adopted to replace the traditional Mg-bearing fluxFlux , i.e. serpentine. The laboratory pot sinteringSintering tests show that, this new technique increases sinter productivity and tumble index by 4.12% and 10.63%, respectively, and reduces solid fuel rate by 6.35%. The mineralogical studySintering mineralogical study of product sinter shows that the addition of ferronickel tailingFerronickel tailing contributes to the increase of the amount of SFCA by 4.03%. Mg and Al elements were found to migrate into magnetite grains to form three types of spinel solid solutions, i.e. (Fe, Mg)Fe2O4, Fe (Fe, Al)2O4, and (Fe, Mg)·(Fe, Al)2O4. Meanwhile, eutectic compound melts were obtained by the co-melting of kirschsteinite (CaO·FeO·SiO2), monticellite (CaO·MgOMgO ·SiO2), and fayaliteFayalite (2FeO·SiO2).

The growth of iron whiskersIron whiskers during the reductionReduction of ironIron ore fines is the main cause of fluidized bedFluidized bed bond loss. In this paper, the influence of mechanical carbon coatingMechanical carbon coating on the reductionReduction behavior of magnetic ore powderMagnetic ore powder is studied in detail. Firstly, the reduction kineticsReduction kinetics of bituminous coal-coated magnetic ore powderMagnetic ore powder and anthracite-coated magnetic ore powderMagnetic ore powder under different conditions is studied. Then, the influence of reductionReduction temperatureTemperature on the surface morphologyMorphology of bituminous coal-coated magnetic ore powderMagnetic ore powder and anthracite-coated magnetic ore powderMagnetic ore powder after reductionReduction is studied. The scanning electron microscope results show that the carbon source of bituminous coal-coated magnetite ore powders can effectively inhibit the formation of iron whiskersIron whiskers in the reductionReduction process of ironIron ore powders.

In order to solve the pollution caused by waste plasticsWaste plastics and improve the reductionReduction rate of carbon-bearing pelletsCarbon-bearing pellets , a new idea of co-carbonizationCarbonization of plastics with different kinds of coal was put forward in order to achieve the purpose of clean treatment of waste plasticsWaste plastics and cost-saving in ironIron and steelSteel industry. Basic research on the application of this new type of mixed carbonizationCarbonization reductant has been carried out. Effects of reductionReduction temperatureTemperature , types of reducing agents, types of iron oresIron ores and batching methods on the metallization degrees, and morphologies of reduced carbon-bearing pelletsCarbon-bearing pellets were systematically studied. The results show that when the raw material is magnetite ironIron concentrate, the addition of mixed carbonizationCarbonization reductant carbonized by anthracite and PE plastics can improve the reductionReduction rate of carbon-bearing pelletsCarbon-bearing pellets , but it will cause a certain degree of expansion.

In order to further explore the application of CO2 in vanadium extractionVanadium extraction in combined blowingCombined blowing converter, the initial injection temperatureTemperature was 1300 and 1320 °C, and the CO2 ratio changed with the injection time of 1, 3, 6, and 10 min when the initial proportion was 10, 15, 20, and 25%, and finally reached 40% for segmented combined blowingSegmented combined blowing. The variation of C and V contents and bath temperatureTemperature at different initial injection temperaturesTemperatures was investigated, and compared with the constant-ratio combined blowingCombined blowing with CO2 ratio of 10, 15, 20, 25% at 1320 °C. It was concluded that the optimal initial injection temperatureTemperature of segmented blowing is 1300 °C and the optimal initial injection flow is 15%, which has little impact on the vanadiumVanadium oxidation rate, and the carbon retention effect is better than the constant-ratio blowing, and the end temperatureTemperature can be properly controlled.

GasificationGasification behaviors of biomassBiomass using vanadiumVanadium titanomagnetiteTitanomagnetite (VTM) as oxygen carrierOxygen carrier was studied in this paper. Effects of temperatureTemperature and presence of VTM on the gasificationGasification rate of C and H, and syngas components were investigated. The results of biomassBiomass gasificationGasification without VTM showed that the gasificationGasification rate of C and H increased from 24.8 and 34.8% to 42.5 and 54.8%, and the proportion of CO and H2 in syngas increased from 34.9 and 2.6% to 40.4 and 5.2%, respectively, as the temperatureTemperature increased from 700 to 1000 °C. When the VTM was added in biomassBiomass gasificationGasification at 1000 °C, the gasificationGasification rate of C and H and proportion of CO increased by 14.8%, 10.2%, and 14.0%, respectively. The VTM promoted the cracking of tar, and the lattice oxygen participated in biomassBiomass gasificationGasification . Meanwhile, the ironIron metallization ratio and reductionReduction degree were 82.6% and 90.1%.

Tantalum joined the list of 43 critical raw materials (CRM) within the latest report of the European Commission, published in 2017. Global Ta and Nb ore production, publicly known as Coltan, is dominated by D.R. Congo and Rwanda accounting for a combined share of at least 60%. Recycling constitutes an evolving chance for European countries to lower their complete reliance on importation. Consequently, tin slags as well as process residues like dusts or sludges are processed by pyrometallurgical treatment and hence offer great economic potential due to the content of valuable Ta2O5. FlowabilityFlowability tests with various atmospheres are performed to evaluate the similarity of industrial and synthetic slags. These experiments, thermodynamicThermodynamic FactSageFactSage simulations plus slagSlag viscosityViscosity calculations provide a solid foundation for follow up high-temperatureTemperature furnace rheometer trials which deepen fundamental knowledge about such melts and improve existing process steps.

MolybdenumMolybdenum belongs to the group of refractoryRefractory and alloying rare elements, which are used in industry mainly as pure metals and as alloying components in ferrous and non-ferrous alloys. The effect of the electron beamElectron beam melting and refiningMelting and refining technology on the processing of molybdenumMolybdenum concentrate under different process conditions is examined in the present work. The influence of the electron beamElectron beam power and refining time on the composition variation, microstructures of the metal samples, and degree of refining of molybdenumMolybdenum is studied in order to improve the quality of the obtained metal ingots. ThermodynamicThermodynamic conditions of melting and refiningMelting and refining of molybdenumMolybdenum and the removal efficiency of the controlled impurities are also evaluated and discussed. The results show that a maximal overall removal efficiency is seen at 17 kW beam power for a 5 min melting time and allow us to formulate requirements on the process conditions in order to improve the quality of the obtained metal material.

Stainless steel pickling sludgeStainless steel pickling sludge is a kind of hazardous solid waste, which mainly contains CaF2CaF2 , CaSO4, and Fe(OH)3 depending on the pickling and precipitating procedure. In order to depress the decomposition of CaF2CaF2 to form toxic fluorine-containing gas at high-temperatureTemperature metallurgical process, this work was aiming at the utilization of CaF2CaF2 from stainless pickling sludge by preparing cuspidine glass-ceramicsCuspidine glass-ceramics . Firstly, carbothermic reductionCarbothermic reduction and magnetic separationMagnetic separation were conducted to recover ironIron , in which pickling sludge was reduced at 1000 °C for 1 h by using 5% coke as a reducing agentReducing agent and separated by magnetic separationMagnetic separation with the magnetic intensity of 0.1 T. The main composition of the magnetic concentrate was Fe and Fe3O4 with the corresponding iron recoveryIron recovery more than 80%. Subsequently, the non-magnetic material was mixed with Ca(OH)2 and cullet to prepare cuspidine glass-ceramic. After roasted at 900 °C for 2 h, a cuspidine glass-ceramic with compressive strength of 65 MPa and porosity of 39.74% could be obtained.

PyrolysisPyrolysis has recently received much attention as a promising technology for recycling all the valuable materials from wastes. This study investigated the thermal degradation behaviors of the waste steel tailingsWaste steel tailings and the recoveryRecovery of ironIron from waste steel tailingsWaste steel tailings using magnetic separationMagnetic separation after pyrolysisPyrolysis . Thermogravimetric (TG) and differential thermogravimetric (DTG) analyses were performed to study the mass loss characteristics. The main pyrolysisPyrolysis temperatureTemperature range of the waste steel tailingsWaste steel tailings was approximately from 100 to 800 ℃ and the total mass loss was about 30%. The pyrolysisPyrolysis process of waste steel tailingsWaste steel tailings could be classified into four stages. The optimum pyrolysisPyrolysis temperatureTemperature and pyrolysisPyrolysis time of waste steel tailingsWaste steel tailings were at 700 ℃ for 60 min. The pyrolysisPyrolysis residues generated during the process under optimal condition were detailed analyzed by X-ray powder diffraction (XRD). The result showed that the phase composition of ironIron in the pyrolysisPyrolysis residues was magnetite. The results of magnetic separationMagnetic separation showed that the recoveryRecovery of ironIron was 92.66%.

Based on ENFI’s self-developed bottom-blowing continuous copperCopper smelting process, the normal operation bottom-blown copper smelting furnaceCopper smelting furnace is the research object. Based on the determination of the physical parameters of the slag phaseSlag phase and matte phase in the furnace, the bottom-blow furnace model consistent with the actual bottom blowing system is established by using the commercial software platforms. The VOF multiphase flow model and the standard k−ε turbulence model are used to simulate the three-phase flow process of gas-slagSlag -matte in the furnace. The gas–liquid two-phase flowGas–liquid two-phase flow law in the furnace, the velocity field of each phase in the furnace, and the splashing mechanism of the melting furnace are analyzed. The characteristics of each flow region in the furnace are obtained. This study can also provide a reference for the design and operational system formulation of the bottom blowing furnace.

High-temperature centrifugationHigh temperature centrifugation is an efficient and environmentally friendly method for separating and recycling comminuted waste printed circuit boardsPrinted circuit boards (WPCBs). In this research, it was used to recover copperCopper (Cu) from metal-rich particles of WPCBs. Two steps separation process were conducted, and two alloys (SnSn –Cu and Cu–Zn) were obtained at different temperatures. The results indicate that temperatureTemperature has a great influence on the composition of Cu alloyAlloy , while the gravity coefficient only affects the recoveryRecovery rate. At an optimized temperatureTemperature of 1300 °C and a gravity coefficient of 1000, the total recoveryRecovery values of Cu, Zn, Pb, and SnSn were 98.84%, 86.96%, 98.33%, and 92.62%, respectively. By a combination of appropriate hydrometallurgical process and centrifugal separation of metals, this clean and efficient technology achieved a new way of recycling valuable metals from PCBs and effectively preventing environmental pollution of WPCBs.

Lead–silverSilver –antimonyAntimony (Pb–Ag–Sb) melts are obtained during the pyrometallurgical processing of jamesonite (Pb4FeSb6S14). This work examined a new method of super-gravity technologySuper-gravity technology to effectively enrich silverSilver and antimonyAntimony metals contained in Pb–Ag–Sb. The experimental results demonstrate that the silverSilver mainly migrates to the denser lead matrix while most of the antimonyAntimony -rich phase accumulates above it. Following super-gravity enrichment under conditions of 533 K (260 °C), G = 600 and t = 5 min, the mass fraction of Sb in the antimonyAntimony -rich phase reached 90 wt%, and more than 95 wt% of the silverSilver migrated to the lead-rich phase, which could be further recovered during the subsequent electrolytic refining process of lead. The microstructures of samples obtained by super-gravity enrichment and the corresponding enrichment mechanism are discussed.

In this study, a compact process was introduced to prepare the sulfate-based polyanionic nano cathode material Na2(Ni, Fe)(SO4)2 from nickelNickel sulfide concentrate. The Na2(Ni, Fe)(SO4)2 was synthesized with a four-step process, including sulfate roastingSulfation roasting, leachingLeaching-purificationPurification, co-precipitationCo-precipitation, and annealing processes. The crystalline phase identification and microstructure characterization of the final product was performed by X-ray diffraction (XRD) and Scanning electronic microscopy (SEM), respectively. The XRD result shows that the obtained product which was composed of eldfellite compounds Na2(Ni, Fe)(SO4)2 and sodium-rich phase Na6Fe(SO4)4. The SEM reveals that the synthesized material was with a microstructureMicrostructure of nanopore, which might be owing to the nanocarbon powder as nucleation particles can promote the formation of nanometer pore. The nanomaterial Na2(Ni, Fe)(SO4)2, expected to be a promising candidate in energy storage applications as sodium-ion battery, has been synthesized from nickelNickel sulfide concentrate.

The use of zinc kiln slagZinc kiln slag to prepare cermetCermet can realize the recycling of zinc kiln slagZinc kiln slag and promote sustainable development. The thermodynamic analysisThermodynamic analysis of the preparation process was carried out to develop a new method based on sinteringSintering with suitable temperatureTemperature and atmosphere, and obtain suitable component ingredients to prepare excellent properties cermetCermet . The preparation method was powder metallurgyPowder metallurgy method, sinteringSintering temperatureTemperature was 1300–1600 °C. Fe2O3, Al2O3, and Fe powder were added to the zinc kiln slagZinc kiln slag to balance the content of each component in the kiln residue. The mass ratioMass ratio of Fe2O3 to Al2O3 in cermetCermet was 0.53. The content of CaO should be minimized. The content of SiO2 should be 2–5%, and the content of TiO2 should be 24%.