12th International Symposium on High-Temperature Metallurgical Processing

The transfer phenomenon and chemical reactions happening in racewayRaceway play a key role in both metallurgical principle and industrial operation of blast furnace (BF). Hot air with high blasting velocity resulting in efficient gas–solidGas-solid interaction motion, which determines the velocity field and furthermore temperature field, influences the total rate of chemical reaction. A 1/3rd scale 3D coldCold experimentation sector experimental model taking blast air kinetic energyBlast air kinetic energy as similarity criterion is built to study the gas–solidGas-solid interaction motion phenomenon by using 80–110 m/s gas inflow and real coke granule (average dimeter: 10–12 mm). The results indicate that, to study the movement inside of racewayRaceway, using the blast air kinetic energyBlast air kinetic energy as similarity criterion is much more reasonable than the Reynolds number or Froude number.

A high-efficiency and low-power consumption permanent magnetic technology was proposed to modify the poor control of structure and primary carbide of high-carbon stainless steel. One key point of the better application of permanent magnetic technology is the generation of magnetic field with stronger intensity and more even distribution using less magnet. In this study, the permanent magnetic fieldPermanent magnetic field under varying arrangement, thickness, number, and arc degree of magnets was modelled. The results indicated that adjacent magnets with same polarization mode have stronger magnetic field intensity. All the greater magnet thickness, greater arc degree of single magnet and less magnet number under same sum of total arc degree can increase field intensity. The arrangement mode of two 40 mm-thickness magnets with arc degree of 120 and different polarization mode among more than 20 arrangement modes has strongest field intensity and widest range of intensive magnetic flux density along radial direction.

Fluidized bed reactor has become an important branch of non-blast furnace ironmaking due to its high heat and mass transfer efficiency, simple equipment structure, and low cost. In view of the uneven distribution of gas–solid two-phase in the traditional fluidized bed fluidizationFluidization ironmaking process, this paper puts forward a new idea that side stirringSide stirring is applied to the fluidization iron making process to inhibit the sticking. The bed height diameter ratioBed height diameter ratio is a structural factor which has great influence on the hydrodynamic performance of fluidized bed. In this paper, the three-dimensional numerical simulationNumerical simulation of gas–solid fluidized bed is carried out by using Eulerian–Eulerian two-fluid model under the same inner diameter of fluidized bed reactor to study the effect of bed height diameter ratioBed height diameter ratio on two-phase flow in gas–solid fluidized bed.

Based on the first-principles calculations of the density functional theory, the reaction mechanism of carbochlorination of TiO2 with bridge-oxygen defect was studied. The results show that the presence of C promotes the carbochlorination reactions. When C and Cl2 co-adsorbed on the bridge-oxygen defect of TiO2 (001) surfaceSurface, Cl2 molecules dissociate, and all C atoms bond to Ti or O atoms on the surfaceSurface. In the adsorptionAdsorption reactions, O2c atoms are the electron acceptors, and Ti5c(r) atoms are the electron providers. The adsorptionAdsorption energy of the structure that CO formed by C and O2c, and two Cl atoms bonded with Ti5c on both sides is low, and the adsorptionAdsorption energy of this structure is −11.78 eV.

EAF steel-makingEAF steel-making process is a discrete and complex process with complex equipment and wide professional coverage, resulting in many data sources and poor authenticity, accuracy, and real-time performance. In the process of product production, the enterprise's operating capital flow is not clear, and the cost accounting is rough, which seriously affected the cost management of the steel mill. This paper is based on multivariate data acquisition and feature preprocessing. Using Visual Studio 2013 development tools and Microsoft SQL Server 2012 database technology, the cost data collection module, cost real-time monitoring and calculation module, process cost module, cost composition and trend analysis module, and historical cost inquiry module were developed, and the full cost analysisCost analysis modelModel was built to realize the dynamic analysis and optimization of costs in steel-making and production.

In order to obtain the key parameters of the bloomBloom heavy reductionHeavy reduction process in continuous casting, the mathematical model of solidification heat transfer of bloomBloom continuous casting was established by using the general simulation software of billet secondary cooling. Then, combined with Abaqus finite element software, the stressStress–strain and deformation behaviorDeformation behavior of billet was investigated in detail. The results demonstrated that the calculation error tends to stabilize when the size of the reduction roll unit is below 15 mm. The stressStress of billet is distributed symmetrically along the thickness direction, and decreases from the inner arc and the outer arc to the center. The maximum stressStress increases from 119 to 140 MPa in the range of 10 to 30 mm reduction amounts, resulting in the increase of the corner crack tendency. The reduction amount shall be greater than 10 mm to effectively improve the internal quality of the billet. In addition, the side strain of the billet is basically consistent with the deformation distribution in the width direction and has a good linear relationship.

Decreasing chromium loss in the decarburization stage of the Argon oxygen decarburizationargon oxygen decarburization (AOD) refining process is one of the key technologies of 304 stainless steel304 Stainless steel smelting. In this paper, based on the theoretical conditions and production status of a 75 t AODArgon oxygen decarburization furnace, a decarburization and chromium conservation mathematical model of 304 stainless steel304 Stainless steel was established. Using this model, conditions of chromium oxidization in different situations can be predicted, and the required CO partial pressure as well as the gas supply parameters of decarburization and chromium conservation under different smelting conditions can also be calculated. Applying the model on a 75 t AODArgon oxygen decarburization furnace, the side and top combined blowing parameters in AODArgon oxygen decarburization refining process were optimized, and the burning loss of chromium in molten steel was also reduced obviously. In addition, a 379.2 kg decrease of the average consumption of ferrosilicon in the reduction stage has been achieved using the model, and the average smelting cycle was shortened by 6.4 min.

After years of exploitation of tungstenTungsten ore in China, the average grade of tungsten ore has decreased obviously, and the contents of impurities are getting higher and higher. ArsenicArsenic is commonly present in wolframite [(Fe, Mn)WO4] resulting in As-containing leaching residueLeaching residue. The residue is therefore classified as hazardous waste due to its heavy metal content, especially the arsenicArsenic content up to 2 wt%. The arsenicArsenic has to be removed before the residue can be used or treated. A technique involving sodium carbonate roastingRoasting–water leaching has been developed to remove arsenicArsenic from tungstenTungsten leaching residueLeaching residue efficiently. The optimized parameters were determined experimentally, and the reaction mechanisms have been analyzed by FactSageFactSage 8.1. The results show that the arsenicArsenic content in the residue can be reduced below 0.1% and the tungstenTungsten in the residue is also recovered in the same time.

Smelting reductionReduction of lead-rich slagLead-rich slag is a clean technology recently developed in China to produce primary lead metal. The technology has the advantages of more efficient capture of SO2 and lead fugitive emissions and low energy consumption. The extent of the slag reductionReduction was continuously measured by the product gas volume. Effect of PbO concentrationPbO concentration on the reductionReduction of lead-rich slag was determined in the temperature range 1073–1473 K. The reductionReduction of lead-rich slagLead-rich slag by carbon was found to be chemically controlled at early stage and then diffusion-controlled at late stage. The activation energy for chemically controlled reductionReduction decreases with increasing PbO concentrationPbO concentration in lead-rich slagLead-rich slag. The reaction mechanism has been discussed by experimental results and FactSageFactSage 8.1.

In an attempt to reduce phosphorus content of the Mn–Si alloysMn-Si alloys produced by high-phosphorus manganese ores, dephosphorizationDephosphorization thermodynamic experiments of high-phosphorus Mn–Si alloys were investigated by using Al-based dephosphorization agentAl-based dephosphorization agent and CaO–SiO2–Al2O3 covering slags in silicon molybdenum furnace without protection of gas. This research focused on the transform rule of phosphorus element during the process of its entrance into slag, the effect of CaO/Al2O3 (mass ratio of CaO to Al2O3) on dephosphorizationDephosphorization ratio, and the main phases in dephosphorizationDephosphorization slags. The results showed that phosphorus element entered into slag from Mn–Si alloysMn-Si alloys, respectively, conforming to these two routes: [P] → Fe3(PO4)2 → Ca3(PO4)2 → 6 . 2CaO . SiO2–3CaO . P2O5 solid solution and [P] → AlPO4. With increase of CaO/Al2O3, the dephosphorizationDephosphorization ratio increased, and the greatest dephosphorizationDephosphorization ratio could reach 79%.

Hot metal desulfurizationHot metal desulfurization station is an indispensable part of a modern integrated iron and steelmakingIntegrated iron and steelmaking company. In this plant, roughly speaking, at least ninety percent of sulfur in hot metal is eliminated before basic oxygen steelmaking. In the conventional process, stable sulfide-making additives of various kinds and forms are introduced to the hot metal present in torpedo cars or more commonly in ladles. Together with desulfurization reactions, a slag rich in sulfides is collected at the top, and it is then skimmed out. Other than hot metal treatment stage, further removal of sulfur may be accomplished in secondary steelmaking, depending primarily on suitability of metallurgical conditions in that specific vessel. In this literature work, recent experimental studies related to hot metal desulfurizationHot metal desulfurization are reviewed. More emphasis shall be on the works performed after the millennium and specifically in the last decade, including the ones offering new and novel methods.

Due to the accumulation of solid wastes, more and more attention has been paid to the recycle and reuse of basic oxygen furnace (BOF) slag. However, CaO contained in the slag will cause cracks, which has limited the use of the slag as raw material in architecture to a large extent. In this study, the preparation of cementitious materialCementitious material with BOF slagBOF slag has been conducted in lab scale and was enlarged in a 50 kg submerged arc furnace to figure out the feasibility of using it. Through reduction and binary basicity modification, effects of C/O (mole), processing time, and metal recovery have been studied. At 1500 ℃, the higher the C/O, the greater the reduction of Fe, P, and Mn, and the proper C/O was 1.5. With more and more ore tailings added, the slag reduction deteriorated. The reduction speed was lower, while the binary basicity (mass(CaO)/mass(SiO2)) climbed up. The vitrification rateVitrification rate of the modified slagModified slag was also lower, so the ore tailing should be more than 17.5% considering the limit of vitrification rateVitrification rate (90.3%). Finally, cementitious properties such as flexural and compressive strength can reach 5.2 and 45.3 MPa separately, which fulfills the request of Portland cement.

In this work, we studied the evaporationEvaporation of antimony trioxideAntimony trioxide (Sb2O3) from an antimony slagAntimony slag by bubbling nitrogenBubbling nitrogen gas in the temperature range 1000–1300 °C. Experiments were carried out at gas flow rates of 20–60 l/h for 70 min. The slag evaporation ratio and Sb recovery were evaluated by a gravimetric method. Increasing temperature and gas flow rate resulted in a higher slag evaporationEvaporation ratio and Sb recovery. The Sb recovery reached around 69% at 1200 °C with a gas flow rate of 40 l/h. The generated Sb2O3 product consisted of senarmontite and valentinite. With Sb2O3 evaporationEvaporation, the PbO content in the molten slag gradually increased, resulting in an increase of PbO content in the product. Based on the overall economic benefits, the evaporationEvaporation process can be optimized to balance the Sb recovery and the purity of the Sb2O3 product.

The annual output of ferronickel slagFerronickel slag in China has increased rapidly in recent years, causing a serious threat to the environment. In this study, the influence of addition of FACFly ash cenosphere up to 35 wt% on the process of preparing thermal insulation materials from ferronickel slagFerronickel slag was investigated, with an emphasis on the microstructural evolution. When the addition of FACFly ash cenosphere increased from 15 wt% to 35 wt%, along with phase transformations, the microstructureMicrostructure of thermal insulation material varied significantly, featured by conversion from isolated pores to connected pores. The pore size and porosityPorosity of the material increased rapidly from 84 μm and 28% to 140 μm and 47%, respectively, improving the thermal insulation performance of the material.

CleanlinessCleanliness of aluminum-killed ultra-low carbon steel produced through BOF-RH-CC and BOF-LF-RH-CC was comparatively investigated by various test equipment. Three different heating processes were used when the converter tapping temperature was low: reheating by blowing oxygen and Al addition during RH early decarburization stage (Process-A); reheating by blowing oxygen and Al particles addition at the end of RH decarburization (Process-B); and no Al addition at RH decarburization stage but the process was BOF-LF-RH-CC (Process-C). The non-metallic inclusions can be removed obviously in three refining processes. Statistical analysis of inclusion area fraction showed Process-A was substantially less than those in Process-B. Furthermore, the proportion of single inclusion area <8 μm2 increased from Process-A level 85% to Process-C level 95%. Moreover, this study proposed an XGBoost model based on big data miningDatamining methods to investigate the computational simulation and the introduction of the XGBoost model ensured 90% accuracy rate for seeking an optimum refining process.

Cobalt has been the predominant binder for tungsten carbidesTungsten Carbide for almost one hundred years. However, a suitable substitute is required because cobalt faces supply risks, is in high demand for other applications, and is a known carcinogen. Select high entropy alloysHEA (HEAs) are being investigated as potential alternatives to cobalt. However, published fundamental data are lacking for these alloys. Characterization of the high entropy alloysHEA allows for operating parameter identification and optimization for sintering. Phase transition onset temperatures, the kinetic components of heat flow, and green binder vaporization temperatures have been determined by differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA), modulated differential scanning calorimetry (MDSC), and thermodynamicThermodynamics modeling for the selected HEAsHEA.

Tailings are produced by high-titanium blast furnace slag using “high-temperature carbonization-low-temperature chlorination” technology. In this paper, dropletDroplet impactImpact on a heated tailings surfaceTailings surface is experimentally investigated over a wide range of Weber numbers and surface temperatures. The spread of dropletsDroplet into a liquid film on the tailings surfaceTailings surface and dynamics behavior of the dropletsDroplet were observed by a high-speed camera. Five regimes are observed, namely spreading, boiling induced break-up, advancing recoiling, splashing with continuous liquid film, and splashing with broken liquid film. In addition, the effects of Weber number and surface temperature on boiling mode and spread of dropletsDroplet are examined. The scaling law of maximum spreading ratioMaximum spreading ratio with the Weber number is also established, and it agrees well with experimental measurements and the literatures over a range of Weber numbers and high temperature.

The behavior of Ce2O3 inclusions was observed in-situ at the argon gas/liquid steel interface. A fast agglomeration of inclusions was frequently observed. It is found that inclusions usually have rough surfaces and surface chemical heterogeneities, suggesting an undulating contact line around the inclusions on the liquid steel surface. In this work, both the undulating contact line induced capillary forceCapillary force and the resistive drag forceDrag force on inclusions are considered. In calculations, the inclusions are treated as capillary ‘charges’ or ‘multipoles’ through the analogy with electrostatics. The results show that the capillary ‘quadrupole’ assumption best represents the strong pairwise attractive force between inclusions. The resistive drag forceDrag force is dominant compared to the net (inertial) force on the particles by 5 or 6 orders of magnitude. We can conclude that the contact line undulationContact line undulation provides a sufficient attraction for inclusion agglomeration, even for particles smaller than 10 μm.

The liquidus temperature and relative equilibrium system of CeCe containing system have important basic guiding role for comprehensive utilization of rare earth Ce resources, while the lack of thermodynamicThermodynamic information seriously restricts the application of rare earth in steel. The phase equilibriumPhase equilibrium relationship of CaO–SiO2–Ce2O3–5wt.% Al2O3 phase diagram system, which was carried out at 1773 K, and was analyzed by X-Ray Diffraction (XRF), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Energy Disperse Spectroscopy (EDS) and Electro-Probe Microanalyzer (EPMA) was studied in this paper. The isotherms and phase relations of CaO–SiO2–Ce2O3–5wt.% Al2O3 system related to the CeCe slag system containing rare earth elements were obtained at 1773 K. And the phase equilibriumPhase equilibrium data obtained in current work can provide the basis for the control of rare earth inclusions in molten steel and the optimization of relevant thermodynamicThermodynamic database, and provide the theoretical basis for the sustainableSustainability utilization of rare earth resources containing ceriumCe.

As an important source of copper lossesCopper loss to the slag, SO2 bubbles formed in the quiescent settlement zone of smelting furnace bring matte into slag phase through the immiscible matte-slag interface. The penetrationPenetration mechanisms and entrainment mechanisms of large bubbles were studied while the entrainment by micro bubblesMicro bubbles was rarely investigated. In this paper, attachment of matte droplets to micro SO2 bubbles in the industrial smelting slags and laboratory samples have been confirmed by high-temperature experiments. The bubble penetration behaviors through liquid–liquid interfaceLiquid-liquid interface were simulated by the cold model experiments using water and silicone oil. Results showed that fine gas bubbles can pass through the liquid–liquid interface and cause the heavier liquid entrainment. Although the critical bubble penetrationPenetration mechanisms size deduced in previous studies is inconsistent with the phenomenon observed in cold model experiments, it is an important parameter to classify the bubble entrainment regimes which is closely associated with the bubble penetrationPenetration mechanisms regimes. Greene’s theoretical derived values of critical bubble penetrationPenetration mechanisms and entrainment sizes are in good agreement but comparatively higher than the experimental results. The Weber numbers based on the critical bubble penetrationPenetration mechanisms size, heavier liquid density, and interfacial tension under different experimental conditions are normally between 4 and 4.5.

The heat lossHeat loss of furnace body in EAF steelmakingEAF steelmaking process is large and difficult to quantify, which affects the accurate control of smelting end temperature. In this paper, the EAF body is divided into four parts, namely the upper shell, the lower shell, the bottom of the furnace, and the furnace cover. The heat transferTransfer behavior in different regions is studied to explore the characteristics of radiation heat transferTransfer behavior and convection heat transferTransfer behavior between the EAF body and the surrounding environment. A theoretical calculation method of heat lossHeat loss in EAF steelmakingEAF steelmaking process is obtained, which provides a theoretical basis for energy saving and emission reduction of EAF steelmakingEAF steelmaking.

Flash smeltingFlash smelting furnace (FSF) and oxygen bottom-blowing furnaceBottom-blowing furnace (BBF) are the major technologies used in copper industry to produce matte. Different requirements of copper concentrate, furnace arrangement, and operating parameters result in different slagsSlag in FSF and BBF. Quenched slagSlag and matte samples were collected from both FSF and BBFBottom-blowing furnace under normal operating conditions. The slagSlag temperatures were measured directly at the tapping hole by a K-type thermocouple. The quenched samples were analysed by XRF and EPMA to obtain slagSlag bulk compositions, microstructures, and phase compositions. It was found that the FSF and BBFBottom-blowing furnace are significantly different in operating temperature, slagSlag composition, and copper loss mechanisms. Thermodynamic and viscosity analyses of the FSF and BBFBottom-blowing furnace slagsSlag have been conducted to understand two technologies. The results will provide detailed information for selection and optimisation of FSF and BBFBottom-blowing furnace technologies.

The effect of ceriumCerium content on inclusionsInclusions in Si–Mn-killed stainless steels was studied at 1873 K using laboratory experiments. It was found that the addition of Ce had little effect on the removal of oxygen and sulfur. When the total cerium content increased from 0 to 430 ppm, the average diameter, the area fraction, and the number density of inclusionsInclusions in the steel all increased. With the increase of the total ceriumCerium content in the steel, inclusionsInclusions were modified into Ce-containing ones. The inclusionsInclusions transformation sequence was: Al–Si–Mn–Ca–O → angular Ce–O–S → irregular Ce–O–S. The experiment result was consistent with the thermodynamic analysisThermodynamic analysis.

The evolution behaviors of nonmetallic inclusions in 55SiCr spring steelSpring steel were carried out in three melts treated by titanium and calcium in the present study. The composition and morphologies of inclusions were determined by FE-SEM&EDS. The results show that less titanium content more easily modifies the inclusions into the liquid phase ones in Si–Mn–Al deoxidizedSi-Mn-Al deoxidized melt. And more calcium content in steel not only transforms more solid inclusion to liquid inclusions for cleanliness but also avoids the accumulation of titanium oxidesTitanium oxides in inclusions. The thermodynamic calculations of inclusion formation were performed in Si–Mn–Al–Ti–Ca–O steel system at high temperature and during solidification process by using Factsage 7.2, the thermodynamic calculations consistent with the experimental results, which can predict the formation of the inclusions in Ti-bearing Si–Mn–Al deoxidizedSi-Mn-Al deoxidized steel.

Coarse coke breezeCoarse coke breeze can cause delayed combustion and increase the permeability of the sinteringSintering bed. In order to increase the efficiency of magnetite concentrateMagnetite concentrate sintering, the effect of coarse coke breeze addition was investigated in an experimental-scale sinteringSintering pot. The results indicated that under a basicity of 2.15, the increase of coke breeze addition improved sintering speedSintering speed, productivity, and reduction disintegration index (RDI+3.15) of sinter. However, sinter tumbler index and mean diameter were significantly decreased. With increasing coke breeze addition, the maximum temperature increased, while the holding time of high temperature over 1100 ℃ initially increased and then declined. The mineral analysis of sinter showed that as the coke breeze proportion increased, the amount of silico-ferrite of calcium and aluminum (SFCA) decreased, while the amount of magnetite increased and became the main mineral in sinter.

Medium oxygen-enrichedOxygen-enriched blast furnaceBlast furnace that utilizes reducing gas injectionsReducing gas injection is a feasible new ironmaking process that can significantly reduce the coke ratio and carbon dioxide emissions. In this study, a three-dimensional numerical model of lance–blowpipe–tuyereTuyere–raceway zone was established, which was used to study the influence of the reducing gas injectionReducing gas injection angle (30–70°) on the flow and combustion of pulverized coal in a new tuyere of the 50% oxygen blast furnaceBlast furnace. As the injection angle increases, the tuyere kinetic energy first decreases and then increases, and the pulverized coal combustionCoal combustion efficiency increases. Compared with the injection at 30°, the coal particle temperature under the injection conditions of 70° at the raceway outlet increased by 326 K, and the char conversion ratio and the burnout increased by 27.4% and 22.4%, respectively. However, it is worth noting that under the high injection angle, local high temperature appears on the tuyereTuyere wall, which requires cooling to avoid damage to the tuyereTuyere in the actual blast furnaceBlast furnace.

Adding rare earthRare earth elements is a potential control method to remove residual elementsResidual element from molten steel. Influence factors of adding lanthanum to remove arsenic from the molten GCr15 bearing steelBearing steel have been experimentally studied. The results show that lanthanum addition, the melting temperature, and the initial sulfur content significantly affected the removal of arsenic from molten steel. The reaction of lanthanum with sulfur and arsenic occurred within 4 min after its addition. Reactions between lanthanum and the crucible inhibited the arsenic removal. Increasing the amount of lanthanum and lowering the temperature both are beneficial to arsenic removal from molten steel. Fierce competitions existed among the lanthanum's arsenic removal reaction, the desulfurization reaction, and the lanthanum-crucible reactions. For arsenic removal, the initial sulfur content in molten steel must be controlled within an appropriate range.

To better understand the cloggingClogging mechanism of the submerged entry nozzleSubmerged Entry Nozzle, clogging materials were analyzed using scanning electron microscopy and energy dispersive spectrometer. The cloggingClogging material was divided into several layers, including the alumina inclusion layer, solidified steel layer, and nozzle matrix layer. Due to the difference in the morphology and composition of oxides, observed cloggingClogging materials presented different morphologies. Steel droplets were observed at the interface between the nozzle and the cloggingClogging materials, indicating that insufficient preheating may lead to the solidification of the molten steel. Alumina inclusions were easy to adhere to the solidified steel layer, which was the starting of the nozzle cloggingClogging behavior. The alumina inclusions continuously collided and sintered, resulting in the formation of the alumina inclusion layer. Besides, the reoxidation might also lead to the cloggingClogging of the submerged entry nozzleSubmerged Entry Nozzle of Al-killed steelsAl-killed Steels.

Laboratory experiments were performed to study the evolution of inclusionsInclusions in a high sulfur steelHigh sulfur steel with additions of 40, 200, and 800 ppm lanthanumLanthanum. With the increase of lanthanum content in the steel, evolution paths of inclusions were Al–Ca–O → Al–Ca–(La)–O, Al–Ca–O → La–O–S and La–S → La–S, Al–Ca–O → La–O–S and La–S. Thermodynamic calculationThermodynamic calculation results show that the evolution path of inclusions with lanthanum additions was Al2O3 → La2O3·Al2O3 → La2O2S → La2O2S + LaS, which were in good agreement with experimental results. LanthanumLanthanum additions promoted the generation and collision of La-rich inclusionsInclusions and inhibited the precipitation of MnS inclusionsInclusions in the solid steel with the number density and area fraction of MnS inclusionsInclusions decreased obviously. An appropriate amount of lanthanumLanthanum was beneficial to improve the distribution of sulfide and promoted the formation of type I sulfide in the high sulfur steelHigh sulfur steel.

Different amounts of calcium wire were added to the molten steel during the refining processRefining process in industrial trials to study the effect of calcium contentsCalcium content on the size distribution, content, and morphology of inclusionsInclusions. Thermodynamic calculations were also conducted to study the effect of calcium contentsCalcium content on inclusionsInclusions. It was found that with the increase of calcium contentCalcium content in steel, Al2O3 content in inclusionsInclusions decreased while CaS content increased. However, when calcium contentCalcium content was bigger than 30 ppm, the CaO content decreased slightly and the CaS content increased more. As the calcium contentCalcium content in steel increased, the average size and area fraction of inclusionsInclusions decreased, which means that appropriate calcium treatmentCalcium treatment technology will not reduce the cleanliness of molten steel as well as will not increase the proportion of large-sized inclusionsInclusions in the steel.

This paper aims to provide useful knowledge on the use of coal tarCoal tar as binder for the production of iron cokeIron coke. The components of coal tarCoal tar were investigated by gas chromatography-mass spectrometerGC-MS (GC–MS); consequently, the effects of coal tarCoal tar on strengthStrength improvement and structure of iron cokeIron coke were analyzed. The results show that the main components of coal tarCoal tar are benzene and aliphatic compounds, and its pyrolysis resultants are similar to the metaplastMetaplast (fluid phase) components, which is helpful to improve the strengthStrength improvement of iron cokeIron coke. The addition of coal tarCoal tar increases the degree of graphitization, aromaticity, and crystallite size of iron cokeIron coke and reduces the specific surface area and reactivity of iron cokeIron coke, thereby increasing the mechanical strengthStrength improvement and the index of coke strengthStrength improvement after reaction (CSR) of iron cokeIron coke. 3% coal tarCoal tar addition amount was determined as the optimal binder for strengthStrength improvement optimization, and the iron cokeIron coke with 40.21% CRI and 55.86% CSR was prepared.

In this paper, an iron ore with high iron grade and low silicon content was used in pelletizingPelletizing experiments. Specific surface areasSpecific surface area were tested, and it would increase slowly and then have a rapid increase with the increasing of particle sizes. Thirty percentage of the high iron grade ore could be used when −200 meshes content of the ore reached to 89% or the ore was grinded by high pressure rollerHigh pressure roller. Compression strength of firing pellet would decrease, higher than 2500 N/P yet, when the ore was added. SiO2 contentSiO2 content of firing pellets would decrease from 4.22 to 3.36%, a 20.38% decline, while 30% of the high iron grade ore was added.

The influence of Al contents (0.035, 0.5, and 0.8%) on hot ductility of high-strength steelHigh-strength Steel was studied by experimental hot tensile tests in the temperature range of 600–1300 °C and under the strain rate of 0.001 s−1 by a Gleeble-1500 thermal simulation machine. According to the tensile results, the true stress–strain curve was obtained and the reduction of area was calculated. The results showed that when the Al content was 0.035%, the reduction of area of steel was less than 40% at 600, 700, 750, and 850 °C, and when the Al content was 0.5%, the reduction of area was less than 40% at 600–1000 °C and more than 40% at 1000–1300 °C; when the Al content was 0.8%, the reduction of area was less than 40% at 650–1050 °C. Overall, the hot ductility was the worst when the Al content was 0.5%. In addition, the fracture morphology of the samples was observed by the scanning electron microscope.

In this study, a process of magnetizing roastingMagnetizing roasting followed by low-intensity magnetic separationMagnetic separation, which is used to separate and recover iron from low-grade refractory iron ore, was investigated. In addition, the ore is crushed and divided into different sizes and put into the electric rotary kiln at different times to participate in reduction reaction. The optimum magnetizing roastingMagnetizing roasting conditions were obtained as the following: roasting at 800 ℃ for 30 min, mass ratio of lignite to iron ore of 5/1000, and grinding 12 min of roasted samples. Under the optimum roasting conditions, the two main parameters of the recovery process of magnetically separated concentration were obtained as the following: the grade of magnetic concentrate of 61.6 mass% Fe and iron minerals recovery rate of 87.5%. The results could be useful for comprehensive utilization of low-grade refractory iron ore by magnetizing roastingMagnetizing roasting process.

SynthesisSynthesis of submicron tungsten carbideTungsten carbide (WC) particles has been achieved utilizing fluidized reactor technology at temperatures lower than those used in current commercial production. Fluidized bed technology provides improved gas–solid contact in a controlled reaction atmosphere to increase conversion efficiency. A tungsten-bearing activated carbon precursor was prepared and utilized in all experiments to evaluate the effect of time, temperature, and reaction atmosphere on tungsten carbideTungsten carbide synthesisSynthesis. The experimental products were analyzed with a variety of characterization tools including X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The analytical results indicate uniform submicron tungsten carbideTungsten carbide particles were successfully produced at greater than 90% total carbide conversion.

Microstructure and grain size are important factors affecting the mechanical properties of low-carbon bainite steelsLow-carbon bainite steel. The influence of austenitizationAustenitization and cooling rateCooling rate on the phase transformation of low-carbon bainite steelLow-carbon bainite steel was investigated. The results show that the continuous cooling microstructure of low-carbon bainite steelLow-carbon bainite steel was determined by pre-deformation, austenitizationAustenitization temperature, and cooling rateCooling rate. The austenitizing process significantly affected the phase transformation of low-carbon bainite steelLow-carbon bainite steel. When samples were heated in the range of 830–930 °C, their austenite grain sizes were relatively small with a maximum of 12.3 μm; when they were cooled at the cooling rateCooling rate range of 1–30 °C/s, the microstructures consisted of mainly a large amount of ferrite and a small amount of retained austenite. When the austenitizing temperature increased to 1220 °C, the austenite grain size increased to 71.2 μm. The structure was mainly proeutectoid ferrite and granular bainite at the cooling rateCooling rate of 1 °C/s. As the cooling rateCooling rate increased, the amount of proeutectoid ferrite reduced, and the amount of bainite increased, resulting in a higher hardness. When the cooling rateCooling rate was 10 °C/s, the proeutectoid ferrite disappeared completely, and the bainite was further refined.

Aluminum secondary production demand is significantly risen due to high energy consumption and wasteWaste minimization production of primary aluminum production. On the other hand, it is inevitable to have several harmful by-products during secondary aluminum production such as drossDross recycling. In this study, the aim is to obtain high-purity alumina by pyrometallurgical methods in order to use it in ceramic and refractory industry. Within the scope, non-metallic residue of aluminum white dross (NMR of AWD) has been subjected three sets of experiments. In the first set, calcinationCalcination experiments were done for elimination of nitrogen and fine metallic aluminum content of NMR. The effects of temperature and duration on the elimination were investigated at 1000, 1100, and 1150 °C for from 15 min to 2 h in a rotary furnace. It was determined that at 1150 °C and 2 h of duration, 5.21 wt% N was eliminated, and metallic aluminum content was decreased; thus, alumina purity has reached 94.67 wt%.

Laser weldingLaser Welding is widely used in the joiningJoining Steels of materials due to the advantages it provides. This study aims to investigate the suitability of different ferritic stainless steelsStainless Steels to laser weldingLaser Welding method. Within the scope, ferritic stainless steel sheets with a thickness of 0.5 mm of different grades (430, 430Ti and 441) were welded by solid-state disk laser, and welding parameters were determined as 1300 W power, 6 m/min welding speed in continuous wave mode. As a shielding gas, argon was used. Metallographic examinations, SEM–EDS analysis, microhardness measurement were performed, and tensile, cupping tests, and bending tests were carried out with welded and unwelded samples. Thus, the structure and property relationships of ferritic stainless steelsStainless Steels joined by laser weldingLaser Welding were examined and compared. As a result, adequate welding quality could not be achieved in 430 samples, and it was observed that the welding ability was insufficient compared to 430Ti and 441 samples.

Cobalt ferriteCoFe2O4(CoFe2O4) nanoparticles exhibit high magnetocrystalline anisotropy, high coercivity, and medium saturation magnetization. It shows great potential in various fields. So it is an active research topic to synthesize CoFe2O4 with controllable size, different shapes, and magnetic propertiesMagnetic properties. In this study, CoFe2-2xLa2xO4CoFe2-xLaxO4 was synthesized by cobalt ferrite and rare earthRare earth La3+ with the route of sol–gel auto combustionSol gel auto combustion. The results show that rare earth La3+ doping can refine the crystalline grain and change the magnetic propertiesMagnetic properties of CoFe2O4CoFe2O4. When the content of La3+ doping is less than 10%, it can refine the grain and make the grain size tends to homogeneous. Otherwise, it will appear heterogeneous phase La(FeO3). The excessive doping even makes most of the crystal shapes are destroyed and tends to disappear. When the content of La3+ doping is not less than 15%, the coercivity of CoFe2-2xLa2xO4CoFe2-xLaxO4 increased and saturation magnetization decreased. This is expected to control the magnetism of cobalt ferrite by doping rare earthRare earth ions.

Non-metallic inclusionsNon-metallic inclusions with high melting points can easily be crack sources and reduce the service life of spring wire. Refining slagRefining slag can adjust the composition and melting point of inclusion through the reaction with molten steel. Therefore, studying the optimization of refining slagRefining slag systems and controlling the low melting point of inclusions have great significance. Before the optimization, the basicityBasicity (1.1–1.3) and Al2O3 content (>8%) of refining slagRefining slag in VD (vacuum degassing) are high. By optimizing the composition of the slag, the basicityBasicity is controlled at 0.8–1.0, and the content of Al2O3 is less than 6%. After optimization, the results of the plant trials show that the content of dissolved Al in steel is less than 0.0020%, the inclusion ratio with a melting point less than 1400 ℃ increased from 8.33 to 25.58%, and the ratio with the melting point less than 1550 ℃ increased from 61.11 to 84.88%.

The effect of steam injectionSteam injection on emission reduction and the quality index of sintering were studied. The sintering cup test showed that steam injectionSteam injection on the sintering bed surface has the effect of reducing NOxNOx. It was also beneficial to reduce fuel consumption and the emission of SO2SO2. After steam injectionSteam injection, the sinter drum index is slightly increased, the solid fuel consumptionSolid fuel consumption in sintering reduced by 1.64 kg/t, and the ratio of 5–10 mm sintered is reduced by 0.8%. The steam injectionSteam injection improved the sinter quality and reduced the solid fuel consumptionSolid fuel consumption. Furthermore, the effect of steam injectionSteam injection in the middle part of sintering process was the most significant.

The recovery of valuable metals in multisource metallurgical slag is conducive to achieve resource recyclingRecycling and slag utilization. The method of coupling modificationCoupling modification and carbothermal reduction of converter slagConverter slag and copper slagCopper slag as well as the migration of elements and changes in mineral phases in the process were studied. Based on the element mapping of modified slag, under the interaction of converter and copper slagsCopper slag, Fe2O3 and ‘FeO’ could be separated from the relevant structures of the two slags. The reduced metal phase of the modified slag was Fe-Cu-Mn-P crude alloy, and XRD detection of the reduced slags indicated a complex characterization. The factors of the reduction temperature, the modified basicity, and the C/O ratio on the recovery degree of Fe, Cu, Mn, and P were studied, and the optimal technical parameter was determined as 1773 K, 1.0, and 1.0, respectively.

As a polymetallic symbiotic mineral, vanadium–titanium magnetite (VTM) primarily contains iron, vanadium, titanium, and other valuable elements such as chromium, cobalt, nickel, etc. On the other hand, VTM is generally sintered or pelletized for iron making process. Under the worldwide trend of low-carbon metallurgy, hydrogenHydrogen (H2) is a potential option for the further reduction of CO2 emission in both blast furnace (BF) and non-blast furnace ironmakingIronmaking process. Also, H2 promotes the reduction of iron-bearing burden, while its influences on reduction disintegrationReduction disintegration behavior deserves research in details, especially for VTM burden. In this study, the disintegration behavior of VTM pellets in gas mixtures of CO–H2–CO2–N2 was investigated. The effects of gas composition, reduction temperature as well as reduction time on disintegration index were explored. The reduction samples were observed by an optical-microscope for the evaluation of reaction mode.

Inclusions in an interstitial-free (IF) steel slab from the loose side to the fixed side of the width center were detected to investigate the distribution of inclusionsDistribution of inclusions in the slab under the nozzle cloggingNozzle clogging state. The total oxygen (T.O) content of the slab was 11.07 ppm, and the total nitrogen (T.N) content of the slab was 24.96 ppm. Endogenous inclusions in IF steelIF steel were Al2O3 inclusions; TiN inclusions were precipitated with Al2O3 as the core during the cooling process of slab. In the thickness direction from the surface to the center of the slab, the area fraction of inclusions increased from 25.32 ppm to 267.78 ppm, and the maximum value of the inclusion area fraction was 405.62 ppm below the center of the slab. Due to the small cooling rate at the center of the slab, the number density of TiN larger than 10 μm reached 1.64 #/mm2. Under the condition of nozzle cloggingNozzle clogging, the level fluctuation was large in the mold; contrary to the normal condition, the number density of inclusions at the fixed side of the slab was larger than that at the loose side.

The setting of a channel in a multi-strand induction heating (IH) tundish plays an important role in the metallurgical effect of the tundish. In the present work, the influence of channel heightsChannel height with 300, 400, and 500 mm, respectively, on the flowFlow, heat transferHeat transfer, and non-metallic inclusions removal behavior in a dual-channel six-strand IH tundish was studied by establishing a three-dimensional coupled electromagnetic-flow-thermal numerical model and the Lagrangian Discrete Phase Model (DPM). The results show that as the channel heightChannel height increases from 300 to 500 mm, the distribution of the effective magnetic field in the discharging chamber near the coil side gradually moves upwards, and the direction of the electromagnetic forceElectromagnetic force at the exit of channel changes from downwards to upwards. When the IH turns on, the molten steel at the exit of channel flowsFlow from obviously downward to upward with the increase in the channel heightChannel height, but the liquid level fluctuation becomes sharp under 500 mm of channel heightChannel height. When the IH is turned off, the increase of channel heightChannel height can reduce the degree of short-circuit flowFlow at strand 2 and increase the inclusion removalInclusion removal ratio. In addition, turning on the IH can promote the removal of inclusions. Compared with IH turned off, the inclusion removalInclusion removal ratio under IH is increased by 10.13%, 14.27%, and 12.38%, respectively, for 300, 400, and 500 mm of channel heightChannel height. According to the findings of the study, the height of 400 mm is suggested, which can not only avoid the short-circuit flowFlow of strand No. 2 and improve the inclusion removalInclusion removal but also reduce the risk of slag entrapment by excessive liquid level fluctuations.

Experiments and thermodynamic calculations were performed to investigate the effect of slag basicitySlag basicity (CaO/SiO2) on non-metallic inclusionsInclusion in heavy rail steelsHeavy rail steel. With the increased of the slag basicity from the 1.7 to 2.3, the composition of inclusions changed from the SiO2-CaO to Al2O3-MgO-SiO2-CaO. During the rolling process, the full liquid inclusions were rolled to the linear shape inclusions, which was harmful to heavy rail steels. It was proposed that the target of inclusions was the partial liquid inclusionsInclusion instead of the full liquid inclusionsInclusion to avoid the formation of the linear shape inclusionsInclusion. Moreover, the relationship between the composition of the Al2O3-MgO-SiO2-CaO slag and the composition of inclusionsInclusion was calculated using FactSage thermodynamic software. The content of Al2O3 in inclusionsInclusion gradually increased from less than 10% to above 30% with a higher slag basicitySlag basicity. The lower Al2O3 content in slag was beneficial to decrease the Al2O3 content in inclusionsInclusion in heavy rail steelsHeavy rail steel.

B-bearing blast furnace slagB-bearing blast furnace slag is a typical secondary resource of boronBoron enrichment (B), which is produced from the ludwigite ore in ironmaking process. However, B is dispersed in the amorphous phase resulted to inefficiently recover from the B-bearing blast furnace slag. In this manuscript, the phase transformationPhase transformation behaviors of B-bearing blast furnace slagB-bearing blast furnace slag were investigated through varying of MgO contents and B2O3/SiO2 (B/S) ratios based on the equilibrium phase diagram, and consequently, the amorphous B was adequately enriched into Mg2B2O5 crystalsMg2B2O5 crystals. Firstly, Mg2B2O5 crystalsMg2B2O5 crystals as the second precipitated phase were crystallized through adjusting MgO content to 50.00 wt.% and B/S ratio to 1.00 in the primary crystallization region of Mg2SiO4. In addition, the transformation of primary crystallization region from Mg2SiO4 to Mg2B2O5 was achieved through varying B/S ratio to 1.80 and MgO content to 38.00 wt.%, and Mg2B2O5 crystalsMg2B2O5 crystals as the first precipitated phase were fully crystallized.

In this paper, five kinds of magnesia carbon refractories commonly used in the metallurgical industry were selected to explore their thermal shock resistanceThermal shock resistance. The experiment results showed that the maximum residual flexural strength of sample 2# was 8.07 MPa after three thermal shock cycles under the stress of not more than 0.3 MPa, representing the best thermal shock resistanceThermal shock resistance according to the standard. The accuracy of this result was verified through the tests for the linear expansion performance, ratio of high-temperature flexural strength (Re) to Elastic modulus (E). Sample 2# showed a basically identical linear expansion rateLinear expansion rate with that of the high-carbon sample at the test temperature of 1200–1500 ℃. The Re/E indexRe/E index of sample 2# was relatively high at high temperatures. The comprehensive analysis identified that sample 2# performed the best thermal shock stability. Therefore, sample 2# can serve as qualified refractories of a converter bath.

The coal-based direct reductionDirect reduction characteristics of low-grade iron oreLow-grade iron ore during lignite pyrolysis were investigated. Especially, the coal used as reducing agent contains a high percentage of volatile matter and a low percentage of fixed carbon, which could produce a large amount of H2 and CO during pyrolysis at high temperature and improve the speed of reduction reaction. The results show that appropriately increasing the reduction temperature, increasing the amount of reducing agent, and prolonging the reduction time can all improve the index of DRI. At reduction temperature of 1150 ℃, lignite ratio of 20 wt.%, and reduction time of 40 min, the metallization degree of 92.71%, the index of DRI with iron grade of 90.94%, and iron recoveryIron recovery rate of 85.07% were obtained. The results could be useful for comprehensive utilization of low-grade refractory iron ore by the coal-based direct reduction process.

To improve the modificationModification efficiency and effect of hot slagHot slag with mechanical stirringMechanical stirring, the dispersion behavior of modifier particles with stirring time is investigated by numerical simulation. The hot slag is divided into six regions, and the particle number concentrationParticle number concentration in different regions of hot slag is evaluated and discussed further. In addition, the effects of particle size and adding position on the distribution of modifier particle are also elucidated. The results show that four circulation streams on each side of a cross-shape impeller which are beneficial to complete mixing between modifier particles and hot slagHot slag. A dynamic steady state of particle motion in each region can be obtained within 10 s by mechanical stirringMechanical stirring. The particle diameter of 5 mm and adding modifier particle directly to the vortex core of hot slagHot slag are more conducive to hot slagHot slag modificationModification.

Ladle soft blowingSoft blowing plays an important role in the removal of non-metallic inclusionsInclusion in liquid steel. In the present work, a CFD-PBM coupling model was established to simulate the soft blowingSoft blowing process in a 180t ladle. The turbulenceTurbulence behavior of gas and liquid phases in the ladle was accurately described, and the turbulent collision and coagulationCoagulation and growth of medium and small size inclusionsInclusion in liquid steel were investigated. The results show that the inclusionInclusion size is generally smaller than the Kolmogorov microscale with the argon blowing rate of 100–200 NL/min, and the inclusionInclusion motion mainly depends on the molecular viscous action. After soft blowingSoft blowing for 5 min, the collision and coagulationCoagulation and growth behaviors are obvious, and the number density of small inclusionsInclusion is significantly reduced. For the gas flow rate of 200 NL/min, the average diameter of inclusionInclusion increases from 3.94 to 4.25 μm, and the number density of 2-10 μm inclusionsInclusion decreases from 1.0383 × 1013 to 4.4847 × 1012 per m3, which decreases by 56.81%.

The high melting point Al2O3 inclusions in steel can be modified to low melting point calcium aluminate by the calcium treatmentCalcium treatment process, which makes the inclusions easy to grow up by collision and float to remove, thus improving the cleanness of liquid steel. Taking the treatment of molten steel by SPHC in a steel mill as the research object, the budget models of molten steel composition and temperature, calm time, top slag composition, and the amount of molten steel calcium were established based on RH refining data using multiple linear and multiple nonlinear regression analysis methods. The results show that the hit ratio of the multiple linear and multiple nonlinear budget models is 83.8% and 94.6%, respectively, and the multiple nonlinear regression model has better fitting ability and higher hit ratio. The amount of calciumThe amount of calcium is mainly determined by the content of [Ca] and [Al]O and [S] in molten steel before calcium treatmentCalcium treatment. Therefore, in the actual process of calcium treatmentCalcium treatment, the amount of calciumThe amount of calcium should be precisely adjusted according to the specific composition of molten steel.

Spherical metal powders are in great demand in the novel manufacturing industry, such as 3D printing3D printing, plasma spraying, and metal powder injection molding. For the efficient production of spherical metal powder, an innovative method to prepare spherical metal powder was proposed in this paper through re-melting and spheroidizing the irregular shape metal powders at high temperatures. And, the spherical iron powderSpherical iron powder is successfully prepared using direct reduced iron powder. The morphology, particle size distribution, spheroidizationSpheroidization rate, and gas content of the powders prepared were characterized. When the gas ratio of hydrogen increases in the spheroidizing atmosphere, the oxygen content of the treated powder decreases subsequently. Meanwhile, the change in nitrogen and hydrogen content is not obvious. After treatments at 1833 K, the particles below 100 μm present smooth surfaces, and no hollow particles and satellite spheres exist. And, the spheroidizationSpheroidization rate is close to 100%, which is greatly beneficial to improve the flowabilityFlowability.

To realize the gasification dephosphorizationGasification dephosphorization process in the converter slagConverter slag splashing stage for avoiding the P enrichment, the dephosphorized slag can be left for recycling in subsequent furnaces. The migratory behavior of P during the slag gasification dephosphorizationGasification dephosphorization was studied. The results show that the P element in converter slagConverter slag is mainly enriched in the silicate phase. The FeO in the converter slagConverter slag is reduced by the coke into a large-diameter granular elemental Fe phase. The P2O5 in the slag is reduced to P2 steam by coke at high temperature. Most of the P2 steam passes through the gas-slag interface and enters the furnace gas. A small part of the P2 steam will be adsorbed by the nearby elemental Fe phase to form iron phosphide.

A carbothermic reductionCarbothermic reduction process was proposed to recover valuable metals from Sn-bearing lead slagSn-bearing lead slag. The microstructure evolution and phase transition of the carbon-containing pellets during the reduction process were investigated via XRD and SEM–EDS analysis. Results revealed that with the increasing of the reducing agent dosage, the metallization rate of Fe and the volatilization ratio of Zn increased. The metallic iron particles obtained at lower reductant dosage can aggregate much bigger than those obtained with higher reductant dosage due to more liquid phase (Fe2SiO4, Fe–FeS) and lower ash residue. However, excessive reductant dosage can easily lead to the generation of Fe–Pb–Sn alloy in the reduction process, which hindered the further removal of Sn and Pb. When the reductant agent dosageReductant agent dosage was 22% and roasting at 1200 °C for 20 min, the volatilization ratio of Zn, Pb, and Sn can reach 93.31%, 92.5%, and 66.8%, respectively. Valuable flue dust rich in heavy metals was also obtained.

In this paper, the smelting reduction furnace is taken as the research object, and by establishing the “upper space” combustion model, the effects of different top lance positions, different top blowing oxygen enrichment flow, and different inclination angles of top lance inlet on gas velocity distribution and temperature distribution in the furnace were studied. This paper provides guidance for non-blast furnace ironmaking process theoretical and computational basis on aspects of scale-up design, process optimization, and process control.

Sinters and pellets are the main burden of blast furnace in ironmaking industry, and their phase compositions (hematite, magnetite, perovskite, calcium ferrite, silicates, glass phase) will affect the metallurgical propertiesMetallurgical properties (low-temperature reduction degradation index, reducibility, and softening-melting properties). In this paper, based on optical microscope, RGB modelRGB model, and image analysis, the gray range of each mineral phaseMineral phase is preliminarily determined, while the composition and content of different mineral phasesMineral phase in burden can be reasonably calculated by reflectance calculation model. Furthermore, BP neural networkBP neural network method is used to investigate the mapping relationship between mineral phaseMineral phase composition and metallurgical propertiesMetallurgical properties. Therefore, a prediction model of burden mineral phaseMineral phase-metallurgical propertiesMetallurgical properties is established which has reached a certain accuracy, and the influence of the content of each phase on metallurgical propertiesMetallurgical properties is qualitatively analyzed. To enhance the accuracy of the model, it is necessary to enrich the database and improve the modeling method.

Blast furnace slagBlast Furnace Slag (BFS) andConvert converter slagConverter Slag (CS) are the main by-products of the BF-BOF long-process steel production model. In China, the utilization ratio of BFSBlast Furnace Slag is high. CSConverter Slag cannot be widely used in the building materials industry due to its characteristics, which is an important issue for the sustainable development of Chinese steel companies. In this article, FactSage software is used to study the conversion of CSConverter Slag by using the heat of BFSBlast Furnace Slag, and the research results provide a theoretical basis for improving the utilization ratio of CSConverter Slag. The thermodynamicThermodynamic calculation results show that when the temperature is lower than 1200 ℃, the liquid phaseLiquid phase ratio of the CSConverter Slag is higher than that of the BFSBlast Furnace Slag. When the temperature is higher than 1250 ℃, the liquid phase ratio of BFSBlast Furnace Slag is much higher than that of CSConverter Slag. When the mass ratio of BFSBlast Furnace Slag to CSConverter Slag is increased from 5:5 to 9:1, the liquid phaseLiquid phase ratio of the mixed slag at the same temperature will gradually increase. The molten BFSBlast Furnace Slag can absorb the free CaO and MgO in the CSConverter Slag through a variety of eutectic phase and peritectic phase melting reactions, and melt part or all of the high melting point Ca2SiO4. When the proportion of BFSBlast Furnace Slag is relatively high, the fluidity of the mixed slag can be maintained, which provides a guarantee for subsequent processing.