10th International Symposium on High-Temperature Metallurgical Processing

A carbon lossCarbon loss mathematical model was established based on the Fe–O–C balance and traditional engineering method. The cokeCoke carbon lossCarbon loss and carbon lossCarbon loss of coupled direct reductionDirect reduction are calculated based on this model and actual production data of B# blast furnaceBlast furnace in Bayisteel. And then, the model is applied to research the effect of coal ratio, burden metallization rate, blast temperature, oxygen enrichmentEnrichment rate and blast humidity on carbon lossCarbon loss of direct reductionDirect reduction and carbon lossCarbon loss of coupled direct reductionDirect reduction . The results show that burden metallization rate and oxygen enrichmentEnrichment rate have significant influences on carbon lossCarbon loss of direct reductionDirect reduction . The burden metallization rate, oxygen enrichmentEnrichment rate and coal ratio have significant influences on carbon lossCarbon loss of coupled direct reductionDirect reduction . In addition, comparing with 4# blast furnaceBlast furnace in Baosteel, the high-quality cokeCoke can observably reduce carbon lossCarbon loss of coupled direct reductionDirect reduction .

AlkaliAlkali metalMetal can be circulated and accumulated in blast furnaceBlast furnace . In this work, the distributionDistribution of alkaliAlkali in blast furnaceBlast furnace is determined by the calculation of alkaliAlkali balance. Combined with the cyclic of alkaliAlkali in the blast furnaceBlast furnace , the influence of alkaliAlkali on coke ratioCoke ratio is calculated by using blast furnace operation lineBlast furnace operation line . The results show that the circulationCirculation of alkaliAlkali in the blast furnaceBlast furnace increases the coke ratioCoke ratio .

Induction heatingInduction heating is widely used for heat treatmentHeat treatment , providing fastFAST and precise heating effect. A wide range of electromagnetic parameters, such as the structureStructure parameters of coil and the electrical operating parameters, have significant influences on the temperature distributionTemperature distribution of the workpiece in induction heatingInduction heating process, which is important for the subsequent heat treatmentHeat treatment process. In this work, the main factors including exciting current, power frequency, coil inner diameter and coil spacing are chosen to be studied by numerical simulationNumerical simulation . Meanwhile the single-factor experimental design and the Fuzzy Gray Relational AnalysisFuzzy Grey Relational Analysis are combined to investigate the impacts of the four factors on the temperature distributionTemperature distribution , providing great reference value for further research of induction heatingInduction heating . The result shows that, for axial temperature difference of specimen, the impacts of the four factors are ranked from the most important to the least important as coil inner diameter, coil spacing, power frequency and exciting current. While for radial temperature difference, the ranking list of importance becomes exciting current, power frequency, coil inner diameter and coil spacing.

It is of great importance to remove the inclusions as much as possible in the molten steelSteel . The inclusionInclusion collision rate is significantly improved by generating centrifugal flowCentrifugal flow in the tundishTundish with an electromagnetic device, which induces the inclusions to grow and float. However, the electromagnetic device requires an external equipment component that is difficult to maintain. Additionally, a turbulence inhibitorTurbulence inhibitor is commonly used to optimize the turbulence flow in the tundishTundish . This paper describes a novel tundishTundish design with a turbulence inhibitorTurbulence inhibitor that generates swirl flow in a cylindrical zone, which produced an effect similar to the electromagnetic device. The gravitational potential energy of the molten steelSteel from the nozzle is converted into kinetic energy of the swirling flow in the tundishTundish . The inclusion removalInclusion removal rates with various nozzle diameters were investigated, and the optimal turbulence inhibitorTurbulence inhibitor size and structureStructure were identified by numerical simulationNumerical simulation .

In this paper, the design and optimization of tundishTundish size for single-strand slab are studied. A three-dimensional mathematical model is established for calculating the flow field and temperature field of molten steelSteel in the tundishTundish with different length to height (L/H) ratios, width to height ratios (W/H), and angles of edges. The concentration distributionDistribution curves of the tracer at the outlet are calculated by using component transfer equation. On this basis, the average residence times and flow patterns of the molten steelSteel can be obtained. The trajectories and the removal ratios of the inclusions are calculated by using Lagrange particles tracking model and DPM model. The validity of the mathematical model is verified by the results of water model experiment. The optimized L/H ratio and W/H ratio are obtained from the numerical simulationNumerical simulation results, and it can provide a theoretical basis for the tundishTundish used in steelSteel mill.

Developments in blast furnaceBlast furnace (BF) sector have long focused on coke savingCoke saving in ironmaking. In this research, high-carbon metallic briquetteHigh-carbon metallic briquette was proposed as a novel BF feeding material for coke saving in BF. The preparing condition of the proposed high-carbon metallic briquetteHigh-carbon metallic briquette was optimized regarding its carbon contentCarbon content , cold strength and crushing strength after the reaction. GasificationGasification behaviour of the optimally prepared briquette was examined using a custom-built thermalgravimetric analysis device. Results showed that the optimal preparation condition was mhematite/mcoal = 2.0. The activation energyActivation energy of carbon gasificationGasification in the briquette was 166 kJ/mol; analysis of the effective application of the briquette indicated that a suitable addition level of high-carbon metallic briquetteHigh-carbon metallic briquette in the ore layer in BF could suppress the lump cokeCoke gasificationGasification .

The development and utilization of sideriteSiderite is worldwide difficult problem. The conventional beneficiation methods only can get iron concentrate with iron grade 45–50% and recovery 40–55%; the resource utilization is low. The research creatively applies fluidizationFluidization technology in aluminium industry to refractory iron ore roasting, aiming at sideriteSiderite with TFe35.19% and iron carbonate content 91.28%, in the best fluidizedFluidization magnetization roasting conditions, by one magnetic separationMagnetic separation ; the magnetic concentrate with iron grade 59.17% and recovery rate 73.74% was obtained; and the index is good. FluidizedFluidization magnetization roasting is the proper process for refractory sideriteSiderite resource; it is of great significance to enhance the competitiveness of domestic iron ore concentrate and ensure the safety of China’s iron ore supply.

Controlling the emission of ultra-fine particulate matters (PM10 and PM2.5 PM10 and PM2.5 ) in sinteringSintering process is significant for green ironIron & steelSteel manufacturing. In this investigation, the emission profileEmission profile and control technique of PM10 and PM2.5 PM10 and PM2.5 during sinteringSintering process were studied. PM10 and PM2.5 PM10 and PM2.5 characterized high emission concentration in special sinteringSintering areas, which were sinteringSintering stage-4 to stage-6, and sinteringSintering stage-4 to stage-5, respectively. The emission load of PM10 and PM2.5 PM10 and PM2.5 in special areas accounted for about 63.5 and 47.0% of the total, respectively. Based on these propertiesProperties , spraying organic binder solution on granules during granulationGranulation process was found to improve the absorption efficiency of sinteringSintering bed to PM10 and PM2.5 PM10 and PM2.5 , which made them intensively emitted within sinteringSintering stage-5 and stage-6, with accounting for 74.8 and 74.2% of the total. The research findings were helpful to realize the efficient and economic control of PM10 and PM2.5 PM10 and PM2.5 in practical sinteringSintering plants.

The effects of magnetic field intensity, magnetic field frequency and Al2O3 content on the viscosityViscosity of molten slag in a low-frequencyLow frequency magnetic field were studied in this paper. The flow field of mould fluxMold flux under low-frequencyLow frequency electromagnetic field was simulated by the finite element software. The experimental results showed that under the condition of this experiment, the magnetic field intensity increased from 0 to 30mT, and the viscosityViscosity of mould fluxMold flux (1573 K) increased by 0.8–1.7 poise; the magnetic field frequency ranged from 6 to 12 Hz, and the viscosityViscosity (1573 K)increased by 0.9–1.6 poise; the content of Al2O3 increased from 3 to 7%, and the viscosityViscosity (1573 K) increased by 0.9–2.1 poise. Numerical simulationNumerical simulation results showed that the flow field of mould fluxMold flux is changed under low-frequency electromagnetic field, the amount of the slag in the disordered flow state increased and the viscosityViscosity increased.

In this study, the effects of Cr2O3, FeO and CaO/SiO2 ratio on the apparent viscosityApparent viscosity of the CaO-SiO2-MgO-MnO-FeO-Cr2O3 slags are investigated at 1500 °C. Apparent viscosityApparent viscosity of the slags is measured using the rotating cylinder method and the liquid and solid phases are calculated using the thermodynamic calculationThermodynamic calculation software FactSage. The experimental results showed that the apparent viscosityApparent viscosity of slags increases with increasing CaO/SiO2 ratio and Cr2O3 content and decreases with the FeO addition. The thermodynamicThermodynamic calculations results showed that Cr2O3 content has a minor effect on the mass fraction of liquid phases, nevertheless it can promote the formation of spinels resulting in increased amount of solid phases as well as, increased slag apparent viscosityApparent viscosity . The liquid slag phases were increased with increasing of FeO content therefore, the apparent viscosityApparent viscosity of the slag was reduced. However, the liquid slag phases were decreased with increasing of CaO/SiO2 ratio, which resulted in increased slag apparent viscosityApparent viscosity .

Electric arc furnaceElectric arc furnace (EAF) dust is a kind of secondary resource which contains multiple metallic elements, including Fe, Mn and Cr. Pyrometallurgical processes for recovering metalMetal elements from EAF dustEAF dust have been investigated for many years although they are suffered from high energy consumption due to the spinel-structured components of EAF dustEAF dust . In this study, the thermodynamic analysisThermodynamic analysis of carbothermic reductionCarbothermic reduction of EAF dustEAF dust was performed. The main components of EAF dustEAF dust were magnetite (Fe3O4), hausmannite (Mn3O4) and chromate spinel (FeCr2O4). The gangue minerals were mainly composed of magnesium silicates. The thermodynamic analysisThermodynamic analysis indicated that magnetite and hausmannite can be reduced to metallic ironIron and MnO, respectively. Meanwhile, the chromateChromite spinel will be reduced to chromium oxide and then to form CaCr2O4. The results also demonstrated that the gangue components can promote the separation of Fe and Cr, agreeing well with the experimental results.

Viscosities of Cr2O3-bearing slags were examined under different situations. The influence of Cr2O3 content on slag viscosityViscosity greatly depends on slag basicityBasicity and temperature. In CaO–SiO2–Cr2O3 ternary slags (R = 1.2, 0.8, and 0.5) with a Cr2O3 content lower than 6%, viscosityViscosity decreases with an increase in Cr2O3 content; with increasing Cr2O3 content, the slag viscosityViscosity tends to decrease, especially in the cases of higher basicityBasicity . For CaO–SiO2–10%Al2O3–Cr2O3 (R = 1.2) quaternary slags, when holding at 1953 K for 2 h and measurement was performed during cooling down to 1773 K, viscosities of this slag gradually increased with decreasing temperature to a point and then a sharp increase on viscosityViscosity appeared with further decreasing temperature; above 1873 K, the viscosityViscosity decreased with increasing Cr2O3 content, while below 1853 K, a raise in Cr2O3 content increased the viscosityViscosity . However, in the case of measurement performed from 1813 to 1673 K, the viscosityViscosity increased with an increase in Cr2O3 content. It revealed that the slag viscosityViscosity showed greater dependency on the precipitation of Cr2O3 and their morphologies.

Several slag compositions of differing reactivity were designed as a potential measure for reducing erosion on submergence entry nozzle during continuous casting of high-Mn high-Al steelSteel . Reactivities were determined according to the SiO2 content of the slag considering the reaction between [Al] and (SiO2) at the steelSteel –slag interface. The erosion rate was evaluated by means of the rotating cylinder method; a ZrO2-C rod was immersed in the 1673 K slag sample for two hours, and the erosion rate was evaluated according to the reduction of rod diameter. The effect of slag components Na2O, Li2O, CaF2 and B2O3 on the erosion rate was investigated. The main results indicate that slag with low SiO2 content was more effective in decreasing the erosion rate than conventional high-SiO2 slag. Listed in decreasing order of intensity, the effects of the individual components on the erosion rate are Na2O, CaF2, Li2O and B2O3. The ultimate aim of the mould slag optimization effort is stabilizing the operation by extending the submergence entry nozzle service life.

High-temperature wettability of bonding phase can be elucidated by its contact angle which is an important property reflecting the bonding behaviour between bonding phases and unmelted components. A new method for determining the high-temperature wettability of bonding phase was developed and applied to analyse the liquid phase generation capability, liquid quantity and bonding strength. Results showed that two cryogenic liquid generated areas of andradite and calcium ferriteFerrite formation appeared in Fe2O3–CaO–SiO2 ternary system phase by thermodynamic analysisThermodynamic analysis and the initial temperature of liquid phase formation was divided into three parts. The contact angle will decrease gradually with the increase of furnace temperature until a constant value was reached which measured by a professional software (PolyPro). A positive correlation has been found between contact angle and liquid phase generation ability. This method is meaningful for studying the high-temperature wettabilityHigh temperature wettability of bonding phase.

In this paper, research on dezincificationDezincification in ironmaking and steelmaking processes was carried out. AshesAshes of ironmaking and steelmaking, amylum and bentonite were used as the experimental materials. Bentonite has no significant effect on quality of green pellet by pelletizingPelletizing process; pressing pressure should be controlled at 10 MPa while using press machine to produce cold-bonded pelletCold-bonded pellet ; falling strength of cold-bonded pelletCold-bonded pellet would have a sharp increase while adding a little sodium hydroxide in amylum; ZnO will be removed at a high temperature with carbon contained in experimental materials, but removal rate decreases with the increase of CaCl2; less than 30% of ZnO would be removed by adding calcium chloride without carbon.

In this paper, metallurgical cokes containing different proportion of alkali carbonateAlkali carbonate were subjected to treatment with annealing under N2 temperature from 1100 to 1600 °C to investigate graphitization and metallurgical propertiesProperties of cokeCoke . The annealed cokeCoke powder was characterized using weight method, I-drum tumbling, X-ray diffraction and optical microscope. The results clearly showed that the weight loss increased with the increasing of temperature. The Na2CO3 (or K2CO3) also effectively accelerated the weight loss. Combined with the crystallite structureStructure , it could be shown that the La and Lc of cokeCoke increased with the increasing of temperature, while the d002 revealed the opposite trend. It could also be shown that alkaliAlkali carbonates destroyed crystallite structureStructure . From optical micrographs, it could be seen that the porosityPorosity of cokeCoke increased with the increasing of temperature. The large pores decreased while the micropores increased gradually which revealed that alkaliAlkali carbonates destroyed pore structureStructure . The destruction of potassium carbonate was more obvious.

Turbine discs are currently made of nickelNickel -based superalloys, known for their high strength and creep resistance at high temperatures. Hybrid or dual-microstructureMicrostructure turbine discs allow for significant weight savings, but current methods of joining dissimilar nickelNickel -based superalloys such as friction welding exhibit a heat-affected zoneHeat Affected Zone and localized melting at the interface, leading to weak bonding. Here, we show that field-assisted sinteringSintering technology may be used to sinter the nickelNickel -based superalloy powder CM247LC to high relative density, and the effect of sinteringSintering temperature and time on porosityPorosity , grain size, and mechanical propertiesMechanical properties of CM247LC is investigated. We also show that the same technology may be used to form hybrid discs with a solid Inconel 718 core and a powder-sintered CM247LC rim without the formation of a heat-affected zoneHeat Affected Zone at the interface. Two different joining angles between the two materials in the hybrid discs are explored, and preliminary results suggest that the joining angle does not affect the tensile propertiesProperties of the material interface.

The limoniteXE “Limonite was from Australia, the Fe grade was 56.09%, the grade was up to about 61.88% after ignition, the SiO2 content was 5.62%, Al2O3 content was 3.87%, the gangue content was a little high, the harmful element S,P and alkaliXE “Alkali metalXE “Metal was low, the main metallic minerals are haematite and limoniteXE “Limonite , pyrolusite and pyrite is little; for gangue minerals, quartz is in majority, followed by kaolinite. The proportion of limoniteXE “Limonite was high up to 30% for sinteringXE “Sintering , through rational combination with other iron oreXE “Iron ore and process parameter optimization, the sinteringXE “Sintering was qualified for blast furnaceXE “Blast furnace .

The superheat degreeSuperheat degree in the process of aluminiumAluminum electrolysisElectrolysis is an important indicator for judging the condition of the electrolysis cellElectrolysis cell . In the actual production process, the artificial observation of the fire holeFire hole is usually used for judgment and decision of cell condition. However, the decreasing number and frequent flow of experienced technicians make it difficult to guarantee the accuracy of this complex work. Although there exist some methods for state identification of superheat degreeSuperheat degree , they do not consider flame interferenceFlame interference , resulting in decreasing of accuracy. In view of this fact, a method for state identification of superheat degreeSuperheat degree with flame interferenceFlame interference is proposed, and the proposed method is compared with the existing method on 17 aluminiumAluminum electrolysisElectrolysis cells. The vilification result shows that the proposed method has a better performance than the existing methods. Moreover, it reveals that the proposed method is feasible for identification with flame interferenceFlame interference . In addition, it can provide suggestions for the technicians to judge the state of superheat degreeSuperheat degree .

The tin-bearing middlingTin-bearing middling obtained by flotation in Huanggang, Inner Mongolia, is with SnO2 content of 3–5 wt%, which was stacked and cannot be utilized, leading to the tin resource wasting and environmental pollution. In order to recover this tin resource, the tin volatilization behaviour in the tin-bearing middlingTin-bearing middling during carbothermic reductionCarbothermic reduction in rotary kiln process was studied in this paper. The results show that the volatilization rateVolatilization rate can reach 87.4% and the SnO2 content in the residue decreased to 0.57 wt% under the conditions of Kiln tail: Kiln middle: Kiln head (coal addition ratio) with 1:2:7, the proportion of ball and coal was 20 kg: 20 kg and the pelletsPellets size was 5–10 mm at 1000 °C for 2 h. The research could provide a technical reference for the utilization of the tin-bearing middlingTin-bearing middling .

Sulphation roastingSulfation roasting offers the potential to simultaneously extract valuable metals from multi-metalMetal sulphide mineralsSulfide minerals . In this study, the influences of roastingRoasting temperature and sodium sulphateSodium sulfate addition on the sulphation of valuable metals were investigated under isothermal condition in a static air atmosphere. Additionally, the reaction mechanismReaction mechanism during sulphation roastingSulfation roasting process was characterized by thermogravimetry and differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD) and scanning electronic microscopy (SEM). The results show that the optimum sulphation roastingSulfation roasting temperature range is 600–700 °C. The leach extraction efficiencies of Ni, Co and Cu exceeded 60% when about 10 wt% sodium sulphateSodium sulfate was added during roastingRoasting . The role of sodium sulphateSodium sulfate as a sulphation promoter is attributed to an intermediate phase that acts as a reservoir of SO2.

Oxidative roastingOxidative roasting -ammonia leachingLeaching is the most popular method to extract Mo from molybdenite concentrates. However, the pyrometallurgical process has long suffered from the exhaust gas treatment for acid-making using low-concentration SO2. Technically, gas circulationCirculation can work as an effective means to enrich SO2 in exhaust gas and meantime to reduce overall emissions. However, with SO2-enriched atmosphere, roastingRoasting behaviours of the components in concentrates would be changed, thereby influencing the recoveryRecovery of Mo. In this study, both thermodynamicThermodynamic and experimental studies were carried out to explore the thermal transformations of main components in molybdenite concentrates under SO2-containing atmosphere. Thermal behaviours including oxidation of sulphides and formation of molybdates and sulphates were discussed. It was found that SO2 has a minor effect on sulphides oxidation, and raising the temperature and proportion of SO2 and O2 are effective means to extract the associated Mo from molybdates, which demonstrate the potential of applying exhaust gas circulationExhaust gas circulation (EGC) technology in oxidative roastingOxidative roasting of molybdenite concentrates.

A novel method of effectively recovering rare earthsRare earths (REEs) from rare-earth concentrateRare-earth Concentrate under super-gravity was proposed in this paper. The reconstructions of rare-earth phases in normal gravity and the separation behaviours of REEs under super-gravity were investigated. It was indicated by the results of the mineral phase reconstructions that the rare-earth phases were transformed from original minerals of bastnaesite and monazite into britholite, rare-earth oxide fluoride, rare-earth ferrate and monazite particles at 1423–1523 K, and there was the only solid phase—rare-earth oxide fluoride phase in the sample at 1773 K. In a super-gravity fieldSuper-gravity field , all the rare-earth oxide fluoride crystals were overall intercepted by the filter along the super-gravity direction and effectively separated from the slag melts. The mass fractions of ∑ReO and Ce2O3 in the separated rare-earth oxide fluoride phase increased to 88.31 and 60.76 wt%, the recoveryRecovery of ∑ReO and Ce2O3 were 90.22 and 95.41%, respectively.

A study on sinteringSintering of chromite finesChromite fines was conducted through sinteringSintering pot test. The effect of sinteringSintering parameters including mix moisture content, coke breezeCoke breeze rate, bentonite dosage and sinteringSintering suction was investigated. It was found that conventional sinteringSintering process can be applied to the agglomeration of chromite finesChromite fines as well. Appropriate parameters for chromite finesChromite fines sinteringSintering were 8.0% moisture, 7.0% coke breezeCoke breeze , 2.0% bentonite and 14 kPa sinteringSintering suction. Furthermore, the consolidation characteristicConsolidation characteristic of chromiteChromite sinter was observed by using a microscope, scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). It can be found that the sinter mainly consisted of chromohercynite, forsterite and monticellite. Besides, the element distributionDistribution of Fe and Cr in chromohercynite was quite different. Fe mainly distributed on the outer layer while Cr distributed in the inner layer. The chromohercynite formed from liquid phase has higher Fe and Mg content.

Shougang Jingtang iron and steelIron and steel plant is a new generation recyclable iron and steelIron and steel plant designed according to the concept and principle of circular economyCircular economy . The steelSteel plant is provided with the comprehensive functions of high quality steelSteel product manufacture, high-efficiency energy conversion and waste disposal. In order to realize the cooperation and high efficiency of iron and steelIron and steel manufacturing process, a full process energy flow networkEnergy flow network with carbon flow as the core is designed and constructed to realize energy high efficiency conversion and low carbon green manufacturing. Since Jingtang steelSteel plant was put into production, the efficiency of energy conversion has been continuously improved, and remarkable results have been obtained in high-efficiency energy utilization and high value conversion. The emission of CO2 and pollutants has been greatly reduced, and cleaning production and low-carbon metallurgy have been realized.

Using a Bridgman directional solidificationDirectional solidification furnace, the solidification experiments of a non-quenched and tempered steelSteel were directionally conducted at a temperature ingredient with various growth rates (v = 10–300 μm/s). The values of the dendriteDendrite arm spacing and mean diameter of MnSMnS (dMnS) inclusions in the steady uni-solidification zone were measured. Based on these results, dMnS is more directly related to the secondary dendriteDendrite arm spacing (λ2) than the primary one. Besides, the values of dMnS and λ2 decrease with increasing growth rateGrowth rate . The relationship between λ2 and dMnS with growth rateGrowth rate was determined by linear regression analysis. Therefore, λ2 = 472.06 v−0.375, dMnS = 4.45 v−0.125, and the linear fitting exponent values obtained in this work were nearly same with the previous data in similar systems.

To reduce the construction cost and period of steelSteel structureStructure , high-efficiency welding methods applying high heat input have been widely employed. However, deterioration of the strength and toughness, especially low-temperature impact toughness, due to the coarse grains in the heat-affected zoneHeat Affected Zone (HAZ) of weld steels often comes along with high heat input weldingHigh heat input welding . Thick offshore steelOffshore steel has been developed by Ti deoxidization for the use of high heat input weldingHigh heat input welding . The inclusionsInclusion of the steelSteel were analysed by EPMA and SEM, and the major inclusions were identified to be Al2O3-(MgO) and Al2O3-CaO-(TiO2 TiO2 ) types. The steelSteel plates with different thickness over 40 mm were welded with heat input over 100 kJ/cm, and Charpy impact energies of the welding joints at −40 °C were over 75 J. The nano-sized TiN particles in HAZ were observed and were considered to retard the grain coarsening in the HAZ during high heat input weldingHigh heat input welding .

The concept of “basicityBasicity ” has been central to our understanding of slag chemistrySlag Chemistry for many decades. Traditionally, basicityBasicity has been connected to the level of networking present in a slag, acid slags having a great deal of networking and basic slag having less networking. Qualitatively, this approach provides quite reasonable explanations to the viscosityViscosity of slags, their general interaction with refractories and their ability to dissolve oxidised elements from the metalMetal /matte phase. Various quantitative measures of basicityBasicity have been proposed, such as optical basicityBasicity and the NBO/T ratio, and there have some successful attempts to link these measurements to important propertiesProperties . However, in general, these measures have not been successfully linked to common thermodynamicThermodynamic relationships (other than empirically) or direct measurements from the plant. In industry, weight ratio’s and empirical relationships dominate the control logic of the metallurgical processes. In this paper, we will review what is the current state of knowledge of “basicityBasicity ”, recent research into connecting NBO/T ratios to quantitative measurements and thermodynamicThermodynamic quantities and propose a way forward towards a more rigorous and useful understanding of “basicityBasicity ”.

CloggingClogging of submerged entry nozzles for GCr15 bearing steels has been investigated by industrial experiments coupled with mathematical simulations. It was found that clogs on the submerged entry nozzle with four ports were mainly CaO-MgO-Al2O3 inclusions with the size of 2–6 μm, which cannot be avoided by removal of inclusions from the liquid steelLiquid steel . Cathodoluminescence microscopy was also applied for the characterisation of submerged entry nozzle cloggingClogging . Mathematical simulations were carried out to predict the main cloggingClogging location at the submerged entry nozzle with different types. The results showed that the percentage of inclusions entrapped on the cylindrical submerged entry nozzle and four-port one was 39.7 and 46.5%, respectively. It indicated that the cylindrical submerged entry nozzle helped reduce the probability of submerged entry nozzle cloggingClogging and was beneficial for the improvement of the fatigue property of bearing steels.

The effects of electrolytic parametersElectrolytic parameters on the content of Sc in Al–Sc master alloyAl–Sc master alloy prepared by electrolysisElectrolysis in Na3AlF6-K3AlF6-AlF3 meltNa3AlF6-K3AlF6-AlF3 melt were studied. It is observed that the content of Sc in Al–Sc master alloyAl–Sc master alloy increases and then decreases with increasing the electrolysisElectrolysis temperature and the cathodic current density. Under the electrolysisElectrolysis condition (temperature 950 °C, cathodic current density 1.50 A cm−2 and concentration of Al2O3 1.0 wt%), the content of Sc in the production is increased from 0.81 to 3.87 wt% as the value of the concentration ratio of Sc2O3 to Al2O3 ([Sc2O3]/[Al2O3]) increased from 2 to 6. The analysis of SEM indicates that the production of Al–Sc master alloyAl–Sc master alloy is composed of the aluminumAluminum and the Al3Sc. The distributionDistribution of Sc in Al–Sc master alloyAl–Sc master alloy is uniform.

Based on 300 t top-bottom combined blowing converter bottom air brick location layout problems, ANSYS Fluent software is adopted to establish the three-dimensional model, which simulated the change after the location of the four air brick at the bottom of the flow of molten steel in the converter. The results show that when the bottom blow flow is constant, the four bottom permeable bricks should adopt asymmetric staggered layout, which is beneficial to uniform converter flow field. At the same time, it was found that the angle of the bottom-blown gas supply element is different and the influence on the wall scour is different. When the position of the bottom blown air brick is determined, the inclination angle of the air supply element is 10°, the molten steel has relatively less erosion on the furnace wall of the converter, the flow field in the converter is more reasonable, and the cost is saved for the converter smelting.

Vacuum distillationVacuum distillation of Zn-Al-Fe alloyZn-Al-Fe alloy was discussed based on the experimental investigations of the distillation temperature, the holding time and the pressure of pressing block by response surfaceResponse surface methodology. The experimental results showed that zinc can be satisfactorily obtained from Zn-Al-Fe alloyZn-Al-Fe alloy with suitable distillation temperature, holding time and the pressure of pressing block. The zinc in Zn-Al-Fe alloyZn-Al-Fe alloy was effectively recovered at 1073–1123 K for 60–75 min, and pressure of pressing block was below 50 MPa. When the temperature was 1073 K, the holding time was 75 min and the pressure of pressing block was 40 MPa, the zinc content in the volatiles was about 98.35% and the aluminium content in the residue was about 92.22%.

As one of the important strategic materials, chromium has been widely used in metallurgical, refractory, and chemical industry. Ferrochrome is an important additive in the production of alloy steelSteel. According to the carbon contentCarbon content , it is classified as high-carbon ferrochrome (carbon 4–8%), medium-carbon ferrochrome (0.5–4%), low-carbon ferrochrome (0.15–0.50%), micro-carbon ferrochrome (carbon 0.06%), and ultra-micro-carbon ferrochrome (less than 0.03%). But the most widely used one in metallurgical is the first three. This article mainly summarizes the current development of domestic and international medium-low-carbon ferrochrome and summarizes the preparation methods and the influence factorsInfluence factors in the smeltingSmelting process including reduction temperature, reduction time, the reduction agent, and alkalinity.

Sn-Sb alloySn-Sb alloy is the secondary resources of tin and antimony in metal recovery process and massively exist in the smelting and refining of crude tin. Vacuum distillationVacuum distillation has many advantages such as high recovery efficiency, less pollution and easy operation in disposing of the Sn-Sb alloysSn-Sb alloy . In this study, important factors of Sn-Sb alloySn-Sb alloy separationSeparation by vacuum distillationVacuum distillation were researched, which includes distillation temperature, soaking time and feeding materials (thickness). The optimal experimental conditions of Sn-Sb alloySn-Sb alloy for vacuum distillationVacuum distillation were determined. Under these conditions, temperature was 1474 K, soaking time was 45 min and feeding materials (thickness) were 125 g(0.8 cm), the content of Sn in liquid phase was 98.77%, and the content of Sb in gas phase was 98.77% and the direct yield of Sn was 96.01%. It was indicated that vacuum distillationVacuum distillation is an effective method for Sn-Sb alloySn-Sb alloy separationSeparation and tin and antimony collection.

Commercial methods for synthesizing tungsten carbideTungsten Carbide require large energy inputs due to the high temperatures and grinding processes associated with production. In this study, tungsten carbideTungsten Carbide was synthesized by adsorbing tungstate anions from aqueous solutions onto an activated carbon matrix. The tungsten-loaded precursor was carburized under mixtures of hydrogen, methane, and carbon monoxide to produce tungsten carbideTungsten Carbide at temperatures significantly lower than most commercial operations. Tungsten carbideTungsten Carbide was synthesized at temperatures below 1000 °C with conversion to tungsten carbideTungsten Carbide exceeding 90%. The adsorptionAdsorption and carburization processes were modelled and optimized using experimental design techniques. The effects of time, temperature, initial tungsten concentration, and pH were considered for modelling adsorptionAdsorption behaviour, while carburization behaviour was modelled on the effects of time, temperature, carbon contentCarbon content , and reducing gas compositionComposition . Carburization products were characterized using X-ray diffraction and scanning election microscopy. The adsorptionAdsorption of tungstate anions was measured using inductively coupled plasma optical emission spectroscopy.

Effects of CeO2CeO2 on melting temperatureMelting Temperature , viscosityViscosity and structureStructure of mold fluxes for the continuous casting of rare earthsRare earths alloyed heavy railway steels were studied. Results showed that the melting temperatureMelting Temperature of mold fluxes with 0, 4, 8 and 12 wt% CeO2CeO2 contents were 1066, 1088, 1090 and 1102 °C, respectively. Moreover, the viscosityViscosity values at 1300 °C were 0.40, 0.38 and 0.34 Pa s, but the viscosityViscosity of slags with 12 wt% CeO2CeO2 could not be measured because slags were solid. Therefore, the viscosityViscosity at 1300 °C decreased with the increasing of CeO2CeO2 contents, although the melting temperatureMelting Temperature increased. Raman spectroscopyRaman spectroscopy and X-ray photoelectron spectroscopy (XPS) confirmed that CeO2CeO2 enhanced the de-polymerization of mold fluxes, and the relative percentage content of O2− in melts increased, leading to the viscosityViscosity decrease at 1300 °C.

Under vacuumVacuum conditions, ranging 5 to 80 Pa, orthogonal experiments were conducted by controlling the distillation temperature and holding time to study the lead vaporLead vapor condensationCondensation conditions and nucleationNucleation growth mechanism. The results showed that the condensing temperature range of lead vaporLead vapor concentrates in the region between 510 and 720 °C. Among them, the condensationCondensation effect was best in the region from 550 to 660 °C, and more than 80% of the lead condensed in this region. When the ambient pressure changed from 5 to 80 Pa, the temperature of the lead vaporLead vapor condensate would change around 50 °C. By scanning electron microscopy, the condensationCondensation of lead vaporLead vapor was found to be droplet condensationCondensation . The presence of temperature, pressure and gas all affected the nucleationNucleation and growth of lead. As the degree of undercooling increases, the condensed particles of lead gradually decreased.

To clarify the effect of aluminiumAluminum on the formation of intragranular acicular ferriteFerrite (IAF) in Al–Ti–Mg deoxidized and rare earth-treated steels with different S content, the thermodynamic calculationThermodynamic calculation and scanning electron microscope (SEM) with energy dispersive spectrometer (EDS) were used to study the distributionDistribution and compositionComposition of inclusionsInclusion . The results showed that the addition of Al led to the increase of mean size of effective inclusions. With the content of Al increasing from 0.0027 to 0.0086 wt%, the main inclusionsInclusion in the low S steels changed from La2O3 to LaAlO3 and the proportion of IAF decreased rapidly. However, the inclusions in the high S samples were mainly composed of La2O2S or LaAlO3 and MgO with MnSMnS precipitating on the surface of them. As the Al content increased from 0.0030 to 0.0097 wt%, the main compositionComposition of core evolved from La2O2S to LaAlO3, but the proportion of IAF slightly changed. As the Al content approached 0.03 wt%, the proportion of IAF decreased rapidly and a plenty of upper bainite or widmanstatten were discovered.

FactSage software and SEM + EDS were introduced to determine the compositionComposition of nucleation inclusionNucleation inclusion in Ce-treated Ti–Mg deoxidized C–Mn steelSteel with Ce content ranging from 0 to 0.036 wt%. The nucleation mechanism of inclusionInclusion in tested steels was investigated simultaneously. The experimental results showed that the compositionComposition of inclusionInclusion in the Ti–Mg complex deoxidizedTi–Mg complex deoxidized steelSteel changed from MgO + MgAl2O4/MgTi2O4 + MnSMnS to MgO + MgAl2O4/MgTi2O4 + CeAlO3/Ce2O2S + MnSMnS after Ce treatmentCe treatment , while there was no significant change in the content of Ti(C, N). The mass fraction of Ce2O2S was markedly increased with the increase of Ce. The addition of Ce enhanced the probability of nucleation of acicular ferriteFerrite on inclusionInclusion . The nucleation mechanism of acicular ferriteFerrite induced by inclusionInclusion containing Ce was manganese-depleted zone (MDZ) based on the line scanning results and the low lattice mismatch between Ce2O2S and ɑ-Fe.

The effects of La additionLa addition on the inclusions, microstructures, and high-temperature mechanical propertiesMechanical properties of as-cast FeCrAl alloysFeCrAl alloys were investigated by using scanning electron microscope (SEM), energy disperse spectroscopy (EDS), and hot tensile tests. The characteristics of inclusions were examined, and further discussions focused on the analysis of thermodynamicThermodynamic calculations. The results showed that after La additionLa addition , AlN inclusions were likely to have cores of La-containing particles. Under the conditions of this study, La2O2S and La2O3 inclusions were the main La-containing precipitates and could act as the nucleus for the heterogeneous nucleation of δ-Fe to refine grains. The microstructureMicrostructure comparison of the two studied alloy ingots indicated that both the columnar and the equiaxed grains were refined after La additionLa addition . A series of tensile tests were carried out at temperatures from 973 to 1673 K under a constant strain rate of 1 × 10−3 s−1 to investigate the high-temperature mechanical propertiesMechanical properties . Both the tensile stress and the hot ductility were improved at the studied temperatures after La additionLa addition .

Impurities such as copperCopper , tin, zinc are included in a steelSteel scrap. It is needed to remove these impurities when the steelSteel scraps are recycled, since the elements are harmful for mechanical characteristic and workability of some steels. However, copperCopper cannot be removed by a traditional smeltingSmelting by oxidation. In this study, it is investigated to remove copperCopper from steelSteel by using iodineIodine . IodineIodine was added to molten Fe–Cu alloy at high temperature, CopperCopper iodide (CuI2) gas was formed, and the copperCopper content in the alloy decreased. By this method, the copperCopper in the alloy can be removed to gaseous phase easily. The relationships between removal rate of copperCopper and experimental conditions, such as temperature, mass of iodineIodine , and so on, were investigated.

In order to figure out the effect of chemical compositionComposition on the crystallization behaviourCrystallization behavior of rare earth phase in rare earth slagRare earth slag , the quaternary system SiO2–CaO–CaF2–Ce2O3 SiO2–CaO–CaF2–Ce2O3 slags were made by pure chemical reagent at 1673 K in muffle furnace. The mineral phases and micromorphology of slags were detected by the X-ray diffraction and scanning electron microscope (SEM), respectively. The results show that grains of RE-containing mineral grow very well and the equivalent diameter of grains is about 100 μm when the basicityBasicity is about 1. The effect of CaF2 on the crystallization of the rare earth phase is complex. With the increase of basicityBasicity , the crystallization of the rare earth phase is increasing and the RE-concentrating phase exists in a rod-like structureStructure . But when the alkalinity is up to 2.0, the distributionDistribution of RE-concentrating phase becomes dispersive and the crystals of rare earth phase have no definite shape. The major minerals are fluorite, cuspidine, RE-concentrating phase and substrate phase.

The electric arc furnaceElectric arc furnace (EAF) is used to produce steelSteel , primarily from steelSteel scraps, using electricity and chemical energy. Oxy-fuel burners firing natural gas (NG) are widely used in EAF operation during both the scrap preheating and melting stages. Excess oxygen is normally used to improve heating efficiency. SteelSteel scrap oxidation increases the scrap temperature and reduces the scrap melting point. In this paper, a numerical study is conducted to simulate the steelSteel scrap preheating process using oxy-fuel combustionCombustion . A three-dimensional computational fluid dynamics (CFDCFD ) model was developed with detailed consideration of gas flow, oxy-fuel combustionCombustion , scrap oxidation and multi-mode heat transferHeat transfer between gas and solid scrap. The effects of scrap oxidation on the scrap preheating were also investigated. Model validation was conducted using experimental data obtained from a small-scale scrap preheating furnace. The model can be applied to industrial EAFs to investigate the effects of operating parameters on the scrap preheating process.

Hot-dip galvanizing drossGalvanizing dross is a valuable by-product and contains high levels of zinc and some ironIron impurities. In this work, the super-gravity technology was applied to removing ironIron impurities from an industrial galvanizing drossGalvanizing dross . Firstly, the enriching behaviour of ironIron phase was investigated in different super-gravity fields. The floatation movement of ironIron phase was greatly intensified by super gravitySuper gravity , leading to an ironIron -rich layer in the top area of the sample. Then, the separation of ironIron impurity from galvanizing drossGalvanizing dross was further carried out via filtration enhanced by super gravitySuper gravity . The majority of the ironIron impurities were retained in the upper residue by a filter felt, with the filtered zinc purified significantly. The efficiency of separating increased with increasing gravity coefficient (G). At G = 600, about 99.2 wt% ironIron was removed and the filtered zinc with a purity of about 99.9 wt% can be directly used as galvanizing zinc.

In this paper, we presented an investigation of the theoretical and the industrial definitions of the metallic calcium production by metallothermic process in the vacuum atmosphere. In the studies, Al is the only reductant that is used for the metallothermic calcium production. In experiments, effects of percentage of Al stoichiometry as a reductant, time variances of reduction and temperature of reduction were investigated. In this study, experiments were carried out at 1200, 1250, 1300 °C and 100% Al, 125% Al and 150% Al stoichiometry to produce metallic calcium from the residue of metallic magnesium production residue. All raw materials and residue phases were characterized by using atomic absorption spectrometry (AAS), X-Ray Diffraction Spectrometry (XRD) and chemical analysis techniques. From the results of these experiments, it was understood that the use of Al with the increasing stoichiometry increases the efficiency of the metallic calcium production with the increase of reduction time.

Red mudRed mud can be regarded as a by-product of aluminiumAluminum 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. The authors have recently started a laboratory-scale project dealing with stepwise recoveryRecovery of valuable elements from red mudRed mud of Seydisehir AluminumAluminum Plant, Turkey. The first step is related to recoveryRecovery of ironIron and pyrometallurgical methods (smeltingSmelting and solid-state reduction) will be performed. Nonferrous metals will then be selectively leached in the second step. In the extent of the present work, a literature review relevant to the smeltingSmelting studies for recoveryRecovery of ironIron from red mudRed mud was presented.

In this paper, the technology that acid leaching slagAcid leaching slag was dried by microwave heating was studied. The influence of microwave power, microwave dryingMicrowave drying time, material mass and their interaction on the relative dehydration rateDehydration rate of acid leaching slagAcid leaching slag were investigated using response surface methodologyResponse surface methodology (RSM). Based on the central composite design (CCD), a quadratic model was developed to correlate the preparation variables to the dehydration rateDehydration rate . The optimum conditions for drying acid leaching slagAcid leaching slag has been identified to be a drying temperature of 100 °C, drying duration of 12 min, microwave power of 750 W and material mass of 50 g. The relative dehydration rateDehydration rate of microwave dryingMicrowave drying acid leaching slagAcid leaching slag could reach 97.87% which is very close to the predicted dehydration rateDehydration rate of 98.81%, indicating that the response surface methodologyResponse surface methodology optimization of process parameters for dehydration rateDehydration rate of acid leaching slagAcid leaching slag by microwave roastingRoasting are reliable.

The effect of core diameterCore diameter on the compressive strengthCompressive strength and porosityPorosity of Itakpe iron oreIron ore pelletsPellets has been studied. The holes at the centre of the pelletsPellets were introduced using balls of combustible materials (palm kernel husk, rice husk and sugar cane husk) of various sizes (2, 3, 4, 5 and 6 mm). The produced green pellets were dried and fired, chemical composition, physical and mechanical properties were determined using standard methods. The results showed that the chemical compositionComposition of the pelletsPellets produced is acceptable and can be used commercially and the palm kernel husk has the best compressive strengthCompressive strength with 7.16 KN/mm2 while the porosities were in the range of 25–31%. The result also showed that good porosityPorosity and maximum compressive strengthCompressive strength were achieved with hollow pelletsPellets formed with combustible materials of diameter 4 mm for all the samples.

With increasing application of oxygen-enriched or even oxygen blast furnaceBlast furnace ironmaking technologies, more intensive indirect reduction, followed by softening and melting, of iron oreIron ore pelletsPellets may take place in the blast furnaceBlast furnace . In this study, the correlation between reduction degreeReduction degree and softening and melting propertiesProperties of pelletsPellets was investigated. The results showed that with the increased of the reduction degreeReduction degree , the softening start temperature (Ts) of pelletsPellets did not change significantly and melting start temperature (Tm) obviously increased. The dropping temperature of the pelletsPellets slightly increased with the reduction degreeReduction degree of the pelletsPellets increase. Since the increased temperature range of the softening zone interval (ΔTS/°C) of the pellet was greater than the reduced temperature range of the melting zone interval (ΔTM/°C), the range of the cohesive of the pellet was increased. The permeabilityPermeability of the pelletsPellets was obviously improved as the reduction degreeReduction degree increased. This study provided important guidance for blast furnaceBlast furnace production under high reduction degreeReduction degree conditions.

In the present work, the effect of TiO2TiO2 on the viscosityViscosity and the free running temperatureFree running temperature of the CaO–SiO2–Al2O3–MgO–TiO2TiO2 slag system were studied. At fixed CaO/SiO2 ratio of 1.1, 14 mass pct Al2O3 and 8 mass pct MgO, the viscosityViscosity decreases with an increase in TiO2TiO2 content between 20 and 30 mass pct due to depolymerization of slag structureSlag structure , which means that TiO2TiO2 behaves as a network modifier. The free running temperatureFree running temperature decreases with the increase of TiO2TiO2 content. The change of the apparent activation energyActivation energy is in accordance with the change of viscosityViscosity . Five different viscosity modelsViscosity models and FactSage software were employed to predict the viscosityViscosity . Yan’s model agrees well with experimental data.

SemisteelSemisteel , the main by-product of titania slag smeltingSmelting process of ilmenite concentrate with an electric furnace, is of high sulphur and low carbon. As a result, the semisteelSemisteel cannot be widely used in the steeling process and the market value is relatively low. In order to enhance the added value of semisteelSemisteel , a novel process which was based on a rotary disc atomizerRotary disc atomizer was suggested on semisteelSemisteel to produce ironIron powders in the present study. The oxidation degree of the obtained ironIron granules was studied by thermogravimetric analysis (TG) in the mixture gas of nitrogen and hydrogen.

Adding titanium ore in the blast furnaceBlast furnace is an efficient method to prolong its hearth life. The content of titanium is important for prolonging blast furnaceBlast furnace life. In this study, the dissolution kineticsDissolution kinetics of titanium in carbon-saturated ironIron was studied. The carbon-saturated pig ironCarbon-saturated pig iron was heated to 1200, 1250 and 1300 °C, respectively, and then an appropriate amount of titanium-ironIron alloy powder was added. After a certain period of time, a quartz tube was used to take out the samples from the molten ironIron and the solubility of titanium was measured by an inductive coupled plasma emission spectrometer (ICP). By fitting the experimental results with different solid–liquid reaction kineticsKinetics models, the limiting step of the whole process was determined. The results show that in the process of dissolutionDissolution the mass diffusion is the limiting step. According to the Arrhenius empirical equation, the activation energyActivation energy of the dissolutionDissolution is about 450.96 kJ/mol.

In this study, mineral structures and compositions of Peru raw orePeru raw ore (PRO) were investigated by optical microscope, scanning electron microscope and X-ray diffraction. The results show that PRO is primarily composed of magnetite, haematite, gangue and sulphideSulfide . A small amount of chalcopyrite and calcium phosphate also exist in PRO. Gangues are mainly quartz minerals. Sulphides exist as FeS, Fe2S3 and FeS2, respectively. Sulphides, most of which accrete with gangues, are embedded among ferrous bodies in the form of banding, schistose, or porphyritic structures. The particle sizes of sulphides and gangues are between 200 and 500 μm. Some of them are over 1000 μm. It can be concluded that high liberation degree of sulphides and gangues will be obtained after crushing. After flotation and magnetic separation in Shougang Jingtang dressing plant, the Fe content of PRO was improved from 56.68 to 65.75%. The sulphur content dropped to 0.48% from 3.44%.

Heat capacityHeat capacity is the fundamental thermodynamicThermodynamic parameter, which always be used to obtain enthalpy, entropy and Gibbs energy. Those thermodynamicThermodynamic parameters are critical for chemical reaction, phase equilibrium, material synthesisSynthesis and design. Various calorimetric methodsCalorimetric methods for the measurement of the heat capacityHeat capacity have been reviewed and compared. The measurement methods of the heat capacityHeat capacity can be divided into two types: low-temperature and high-temperature heat capacityHeat capacity measurement, according to the temperature. The principle and equipment have been introduced systematically. It is recognized that the Drop methodDrop method is becoming increasingly important, as it can provide more precise calorimetric data at high temperature that was attributed to its special 3D heat sensor.

Using gas analysis to predict the carbon contentCarbon content at the end point is a new technology within steelmaking. The offgas data of a 100 ton BOF during steelmaking were analysed. The changing rules of the CO, CO2 and O2 volume fractions in the offgas played an important role in judging the status of decarburizationDecarburization in the converter during steelmaking. The carbon deposition reaction error, the CO2 dissolutionDissolution in the west dedusting and the added CO2 from air into offgas had little influence on the predicted carbon contentCarbon content . The carbon integral model had serious errors regarding the predicted results. A new model based on the correlation between the volume fraction of CO and the carbon contentCarbon content in converter was built to predict the carbon contentCarbon content near the end point. The hit rate of the carbon predictionPrediction model was 95.79% for the end point carbon contentCarbon content ≤0.088% with a precision of ±0.03%.

The calcinationCalcination of the strontium carbonate in the rotary kiln is usually carried out at temperatures as high as 1300 °C in practical applications. During the calcinationCalcination process, partial melting of powders occurs at about 1150 °C, due to the partial pressure of CO2. Because of adhesion of the melts to the furnace walls, a ring formation can be seen in the progressive stages. Nevertheless, carbon additions to the SrCO3SrCO3 before calcinationCalcination can prevent the agglomerations by reducing the partial pressure of CO2. In this study, calcinationCalcination of SrCO3SrCO3 is determined by adding metallurgical cokeCoke (0–30%) in a laboratory-scale rotary kiln furnaceRotary Kiln Furnace . Experiments were run at the temperatures between 1100 and 1300 °C. The calcined powders were analysed by XRD. The maximum calcinationCalcination efficiency was obtained with 15% cokeCoke addition at 1200 °C.

In this study, the structural propertiesProperties of the CaO-Al2O3-Li2O-based slag with varying Li2O content have been investigated via molecular dynamicsMolecular dynamics simulation and Raman. The results showed the average bond lengths of Al-O remained at 1.75 Å. The addition of Li2O contributed to the decrease in the bridging oxygen proportion and the network connectivity (Qn) degree, Meanwhile, the five-fold coordinated Al was decreased when mass fraction of Li2O was increased. The results of the Raman spectrum analysis show that the proportion of the complex structural unit Q4 decreases with the increase of the Li2O content, the decrease of the degree of polymerization of the slag network (DOP)DOP indicates that the melt structureStructure becomes simple and consistent with the results obtained by the molecular dynamicsMolecular dynamics simulation.

Earthy graphite is an abundant natural resource with a high content of fixed carbon. It can be considered as a carbon source for steel carburizers. Also, it can reduce the production cost of enterprises. The study is aimed to clarify the kinetics of dissolution reaction and the carbon increase effect. The experiments were carried out by quartz tube sampling at 1873 K, with 0.1 and 0.4% theoretical carbon increase. Effect of added amount on S, N and O content in steel was studied. The results indicated that carbon increase effect was equivalent to some company carbon additives. The added amount of earthy graphite has little influence on S, N and O content. Considering the carbon oxidation reaction consumption during carbon dissolution process, a dynamic model was obtained and the reaction rate constant of the carbon dissolution reaction was calculated.

In the present study, the influences of super-gravity fieldSuper-gravity field with different cooling rates on the distributionDistribution behaviour and the morphologyMorphology of metallic elements of CuCu (II) ion removal alloy were investigated. The CuCu (II) ion removal alloy was obtained from waste printed circuit boards by super-gravity separation, and it contained precious and common metals. The different solubilities of metallic elements in liquid and solid phases lead to component segregation during solidification of alloys. The results showed that super-gravity technology can enrich and distribute metallic elements in the CuCu (II) ion removal alloy according to different densities, and low cooling rate was favourable for the precipitation and enrichmentEnrichment of metals in the CuCu (II) ion removal alloy. When the cooling rate was 2 °C/min, Fe was enriched in the top of the CuCu (II) ion removal alloy, while Pb and Sn were enriched in the bottom of the alloy. The precious metals were combined with Pb and Sn, and they were enriched with segregation of Pb and Sn.

Direct reduced ironIron (DRI) is an indispensable raw material for producing high-quality steelSteel and an alternative to scrap. The Midrex process and the HYL process are the main gas-based direct reductionDirect reduction processes for producing DRI. In this paper, the theoretical analysis of the thermal mass balanceMass balance in the shaft furnace under different H2/CO ratios is carried out. The reduction of gas consumptionGas consumption of different H2/CO ratios was calculated by the formulas. These calculated values are fitted with curves to obtain the relationship between the reducing gas consumptionGas consumption and the H2/CO ratio. Effects of reducing temperatures on the consumption of reducing gas and the influence of H2/CO ratio on the energy utilization rate were also investigated. The calculation results show that the consumption of reducing gas decreases with increasing H2/CO ratio and temperature, and the energy utilization rate of the shaft furnace presents the same trend.

In order to increase the combustion efficiencyCombustion efficiency of coke breezeCoke breeze in sinteringSintering process, thermogravimetry-differential scanning calorimetry tests of coke breezeCoke breeze and sinteringSintering pot tests were carried out. The effects of particle sizeParticle size of cokeCoke on combustionCombustion and sinteringSintering process were examined. The surface air velocity and the exhaust gas compositionComposition of a sinteringSintering machine were also tested in a sinteringSintering strand. The results showed that the fine coke breezeCoke breeze burned quickly, but high ratio of fine particle in coke breezeCoke breeze was not beneficial for the improvement of the sinter quality. The low permeabilityPermeability of the front section of the sinteringSintering machine caused the low combustion efficiencyCombustion efficiency of coke breezeCoke breeze which could be improved by increasing the coarse powder ratio of coke breezeCoke breeze .

Hitherto, the ironIron content after cold-rolling sludgeCold-rolling sludge dehydration in iron and steelIron and steel enterprises has reached up to 60%. However, it contains a lot of chlorine, which is the source of dioxins. And the presence of chlorine makes the cold-rolling sludgeCold-rolling sludge possess highly corrosivity, causing great trouble in the reproduction process. Therefore, dechlorinating experiments on cold-rolling sludgeCold-rolling sludge are of great significance. In this paper, we proposed an efficient way to dechlorinate the cold-rolling sludgeCold-rolling sludge by using high-temperature roastingRoasting method. XRD, SEM and other analytical methods were carried out to characterize the sludge. For comparison, the samples were heated from 200 to 500 °C for 2 h under air atmosphere. The dechlorinating efficiency reaches a very high value of 99%, and the main phase of final product is Fe2O3. In addition, we analysed the reaction mechanismReaction mechanism and clarified the removal form of chlorine in the roastingRoasting process. These findings open up a promising avenue for steelSteel enterprises to deal with cold-rolling sludgeCold-rolling sludge .

A new pyrometallurgical process to extract antimony from stibniteStibnite concentrate was proposed. Thermodynamic analysisThermodynamic analysis of extraction process was conducted. Based on the thermodynamic analysisThermodynamic analysis , the influence of volatilization temperature, volatilization time, blowing oxygen, low melting point slagging on the volatilization rateVolatilization rate of antimony and the residual rate of antimony in the slag was investigated. The results show that high temperature benefits for Sb2S3 and Sb2O3 volatilization reaction and the appropriate temperatures is 1623–1723 K, while Sb2S3 volatilization trend is stronger than that of Sb2O3 at the same temperature. While the stibniteStibnite concentrated content is 75% (mass fraction, similarly hereinafter), FeO content is 16%, CaO content is 16%, the volatilization time is 60 min, the volatilization temperature is 1673 K, low melting point slagging and non-blowing operation are necessary, the primary volatilization rateVolatilization rate of antimony from stibniteStibnite concentrate is 94.78%, the residual rate of antimony from melting residue is 0.2%, and the effect of volatilization antimony from stibniteStibnite concentrate by electrothermal volatilizationElectrothermal volatilization is better.

Titanium is exceptional value to industry, military and consumer applications due to the attractive combination of properties exhibited by metallic titanium and its alloys. The Kroll reduction reaction is a complex heterogeneous exothermic reaction with the possibility of the formation of TiCl2 and TiCl3 as reaction intermediates. Chlorine impurityChlorine impurity has been a significant technical challenge in titanium production ever since the inception of the Kroll processesKroll process themselves. In this investigation, an attempt was made to check the influence factors of titanium spongeTitanium sponge structure, raw materials, times of distillation and vacuum distillationVacuum distillation process parameters on chorine impurity scavenging. The results indicate that the decrease of Ti sponge porosity increased the difficulty of chloride impurities removing. Chlorine content increased rapidly from 0.012 to 0.121% when the system pressure grew from 0.1 to 12 Pa in the vacuum distillationVacuum distillation process. The chlorine content in titanium spongeTitanium sponge was also increased with the increase of NaCl, MgCl2 and CaCl2 impurities in Mg reductant.

The kinetic behaviour of limestone decompositionLimestone decomposition and dissolutionDissolution in converter slagConverter slag at temperatures in the range of 1300–1400 °C was studied. The influence of decompositionDecomposition reaction on the lime dissolution rateDissolution rate was also investigated. The rate-limiting steps of decompositionDecomposition and dissolutionDissolution of limestoneLimestone in converter slagConverter slag were determined on the basis of shrinking core hypothesis. The experimental results indicate that a mixed controlling mechanism of chemical reaction and heat conduction through the produced lime layer should be considered for the limestone decompositionLimestone decomposition in converter slagConverter slag . The rate-controlling mechanisms of the dissolutionDissolution of produced lime differ during the various sub-processes. In addition, examination of the lime microstructureMicrostructure at higher slag temperature revealed that cracks are formed in decomposed lime layer; lime dissolutionDissolution is promoted by molten slag and penetrates through these cracks.

The possible use of low-grade phosphorus-containing iron oreIron ore (LGPIOLow grade phosphorus-containing iron ore (LGPIO) ), a raw and wasted industrial solid material as an adsorbent to remove CuCu (II) ion removal (IICu (II) ion removal ) ion from wastewaterWastewater , was investigated. Studies were carried out as a function of initial pH value, adsorptionAdsorption time, initial CuCu (II) ion removal (IICu (II) ion removal ) ion concentration, adsorptionAdsorption temperature and LGPIOLow grade phosphorus-containing iron ore (LGPIO) dosage. The results show that the CuCu (II) ion removal (IICu (II) ion removal ) ion removal efficiency exceeds 99.65% and CuCu (II) ion removal (IICu (II) ion removal ) ion concentration is less than 0.30 mg/L under the conditions of pH value 6.1, temperature 25 °C, adsorptionAdsorption time 30 min, initial CuCu (II) ion removal (IICu (II) ion removal ) ion concentration 100 mg/L and adsorbent dosage 10 g/L. After CuCu (II) ion removal (IICu (II) ion removal ) ion removal reaction, the CuCu (II) ion removal (IICu (II) ion removal ) ion concentrations completely accord with the requirement of national discharge standard of water pollutants for iron and steelIron and steel industry (GB 13456-2012) (TCu(IICu (II) ion removal ) = 0.5 mg/L) in China. Therefore, it can be concluded that LGPIOLow grade phosphorus-containing iron ore (LGPIO) is a promising low-cost adsorbent which is suitable for the removal of CuCu (II) ion removal (IICu (II) ion removal ) ion from wastewaterWastewater .

NickelNickel resources are mainly in the form of sulphides in China, and chlorination roastingRoasting is one of the most important means of treating nickelNickel sulphideSulfide ore. This paper reports the results of an investigation of the reaction mechanismReaction mechanism of ammonium chlorideAmmonium chloride roastingRoasting of flotation concentrate. The effect of roastingRoasting temperature on the calcine compositionComposition is discussed on the basis of roastingRoasting products analysis by SEM and vibrational spectra. The role of ammonium chlorideAmmonium chloride in the reaction process was investigated in depth by X-ray micro-area analysis. The results show that the chlorination of ammonium chlorideAmmonium chloride is achieved through the solid–solid chlorination and the chlorine-forming reaction, instead of chlorination by HCl formed by the decompositionDecomposition of NH4Cl. MetalMetal chlorides and double sulphate salts are formed during the chlorination roastingRoasting process, and the formation of double salts benefits the thermal stability of the product.

Injecting gas into a ladle shroud to produce fine bubbles is an effective way to promote inclusion removalInclusion removal from molten steelSteel in tundishTundish . The flow and temperature fields in tundishTundish with gas injection into ladle shroud have been investigated based on a k-ε model, Euler two-phase flow model and population balance modelPopulation balance model (PBM), and the relationships between the distributionDistribution of bubble diameter and the conditions of gas injection were investigated. The results indicate that gas injection into a ladle shroud significantly improves the flow and temperature fields in tundishTundish . However, with the increase of gas flow rate, surface disturbance of the molten steelSteel obviously increases. In addition, bubbles gather near the exit of shroud with the increase of gas flow rate, which is not conducive to the collision of bubbles and inclusions. Therefore, the gas flow rates of less than 15.13 m3/h are recommended.

A process for extracting of indiumIndium from indium-enriched cementation produced in zinc hydrometallurgy process was investigated by oxygen pressure leaching and normal pressure and oxygen-rich leaching. The indiumIndium was leached in sulphuric acid medium, at the same time of iron and arsenic were co-precipitated in the form of FeAsO4. The conditions of selective leaching were explored in the presence of oxidant (H2O2). The experimental results indicated that high efficiency of extracting indium and co-precipitationCo-precipitation of iron and arsenic was obtained with the appropriate operation conditions. Which were determined as the initial sulphuric acid concentration of 0.26 mol/L, liquid–solid ratio of 10 mL/g, at 80 °C for 6 h. And in the process controlled the pH between 1.3 and 1.8, the sulphuric acid total amount of 0.75 mol/L and add H2O2 of 0.6 mL/g. Under the optimum conditions, the leaching per cent of indiumIndium was more than 92%, precipitation per cent of iron and arsenic was more than 58 and 60%. Compared with traditional methods of leaching, this process has the characteristics of low acid consumption high leaching rate of indiumIndium and removed simultaneously iron and arsenic.

Taking copper smelting slagCopper smelting slag as raw material, and anthracite and quartzite as additives, the research on comprehensive recoveryComprehensive recovery and harmless treatmentHarmless treatment of copper smelting slagCopper smelting slag is carried out by using a 120 kW submerged arc furnace. Theoretical analysis shows that when the temperature is increased from 1200 to 1450 °C, the slag viscosityViscosity decreases from 0.283 Pa s to 0.033 Pa s. In the range of 1300–1450 °C, selective reduction can be used to comprehensively recover CuCu (II) ion removal , Pb, Zn, Sb and other valuable metals in the slag and deeply remove arsenicArsenic (As) from the slag. The reduction ability of C is better than that of CO. The results show that addition of quartz can effectively reduce the copperCopper content in the final slag. Under the conditions of holding temperature, quartz content, anthracite content and holding time, 1450 °C, 5%, 10% and 120 min, respectively, Zn volatilizes and gets oxidized, in the same time CuCu (II) ion removal settles and gets enriched in matte, and the contents of CuCu (II) ion removal , Pb, Zn, Sb and As in the final slag are reduced to 0.31, 0.043, 0.12, 0.0045 and 0.0014%, respectively. The copperCopper in the final slag mainly exists as sulphideSulfide droplets, and arsenicArsenic in copperCopper matte is mainly distributed in the region where metallic ironIron exists.

Knowledge of the structureStructure and propertiesProperties of aluminosilicate slagsAluminosilicate slags is of great importance in metallurgical processes. The quantitative structural information could be obtained from Raman spectra of the quenched slag samples. The relationship between the propertiesProperties and structureStructure in the CaO-MgO-SiO2-TiO2 TiO2 -Al2O3 system with various Al2O3/SiO2 ratio were studied in present work. Various propertiesProperties such as viscosityViscosity , density, and electrical conductivity can be expected as a simple linear function of structural complexity. It is can be concluded that these physical propertiesProperties are strongly dependent on the structural complexity of aluminosilicate melts. The methodology outlined in the current study can be used to predict the physicochemical propertiesProperties of aluminosilicate slagsAluminosilicate slags when using the high alumina iron oreIron ore in ironmaking process.

The study of hot metalHot metal dephosphorizationDephosphorization by replacing part of lime with limestoneLimestone at temperature of 1350–1400 °C has been carried out in this work, and the effects of slag temperature and substitution proportion of limestoneLimestone were examined. Moreover, the influence of limestone decompositionLimestone decomposition and dissolutionDissolution on the dephosphorizationDephosphorization rate of hot metalHot metal was also investigated. It was found that adding limestoneLimestone instead 50% in mass of lime and the intensive endothermic reaction of limestone decompositionLimestone decomposition would reduce the slag temperature and increase the slag viscosityViscosity . The dynamic condition of dephosphorizationDephosphorization was obviously deteriorated, and the dephosphorizationDephosphorization rate of hot metalHot metal decreased at 1350 °C, while the thermodynamicThermodynamic condition of dephosphorizationDephosphorization could be improved and the dephosphorizationDephosphorization rate of hot metalHot metal increased at 1400 °C.

Based on mass balanceMass balance and heat balanceHeat balance calculation model, the energy utilization of pelletPellets roastingRoasting , gas-based shaft furnaceGas-based shaft furnace reduction and electric furnace smeltingElectric furnace smelting process of high phosphorus oolitic haematiteHigh phosphorus oolitic hematite was calculated, and the influence on energy consumption of the total process with different additives was investigated. Furthermore, the gas-based shaft furnaceGas-based shaft furnace was divided into three parts, namely preheated zone, reduction zone and cooling zone. Taking chemical reactions that taken place in different parts, as well as roastingRoasting pelletsPellets and sponge ironIron with different temperatures into consideration, the relative mass balanceMass balance and heat balanceHeat balance calculation model are established for energy analysis, which can provide a theoretical foundation for energy saving of gas-based shaft furnace reductionGas-based shaft furnace reduction technology.

This paper studies the effect of mixed blowing CO2–O2 gas on the extraction of vanadium and adopts blowing flow and stage blowing, two types of variables, to study the effect of both on the extraction of vanadium from hot ironIron . The initial blowing temperature of the experiment was set to 1300 °C. The experimental results showed that the whole process is sprayed with 15% CO2, and the optimum blowing flow rate is 1.714 L/(min kg). The stage blowing has better vanadium extractionVanadium extraction with carbon retention effect, compared with the whole blowing of 10% CO2, and the end point temperature of the molten pool is decreased by 17 °C. The stage blowing is injecting 10% CO2 in the initial and injecting 15% CO2 in the middle and late period. And it has a higher vanadium oxidation rate than the whole blowing 10% CO2, which can reach 95.14%.

The formation of RE-O-S-As inclusions and corresponding arsenicArsenic content of equilibrium solid solubility were two core issues concerned when adding rare earth to restrain the harm of residual arsenicArsenic in steelSteel . In this paper, some databases of rare earth inclusionInclusion were supplied. The influence of different La content on the formation of inclusions during solidification of As-bearing steelSteel was calculated. The results showed that with the increase of rare earth content, the original inclusions MnSMnS , Al6Si2O13 and Mn2Al4Si5O18 in steelSteel were replaced by La2Al2O6, La2O2S, La2S3, La3S4 and LaS. The formation mechanism of As-bearing rare earth inclusions was analysed under the condition of excess rare earth, and the results showed that the As-bearing rare earth inclusions were formed during the solidification process due to enrichmentEnrichment of solidification frontier elements.