scholarly journals Calculation Model for Activity of FeO in Quaternary Slag System SiO2-CaO-Al2O3-FeO

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 714 ◽  
Author(s):  
Zhi Li ◽  
Guojun Ma ◽  
Mengke Liu ◽  
Jingjing Zou
Keyword(s):  
Carbothermal Reduction ◽  
Theoretical Basis ◽  
Reduction Process ◽  
Slag System ◽  
Copper Slag ◽  
Calculation Model ◽  
Al2o3 Content ◽  
Coexistence Theory ◽  
Slag Structure ◽  
Effects Of Temperature

According to the coexistence theory of slag structure, a calculation model for the activity of FeO in the quaternary system SiO2-CaO-Al2O3-FeO of depleted copper slag was established. The model was used to calculate and analyze the effects of temperature (T), basicity (B), and Al2O3 content on the activity of FeO (NFeO). The results show that temperature has little impact on NFeO. With increased basicity, NFeO first increased slightly, then increased sharply, and finally decreased. It is easier for CaO to combine with SiO2 than FeO to form calcium silicate, which replaces FeO in 2FeO·SiO2 and increases NFeO. However, when basicity is higher than 2.0, CaO not only reacts with SiO2, but also combines with FeO to form calcium ferrate compounds to decrease NFeO. In addition, the activity of FeO decreases with increased Al2O3 content because of the reaction between CaO and Al2O3. The results can be used as a theoretical basis to guide the carbothermal reduction process of copper slag.

Calculation Model of Mass Action Concentrations for CaO-Al2O3-SiO2 Slag System

2012 ◽  
Vol 217-219 ◽  
pp. 39-42
Author(s):  
Hong Ming Wang ◽  
Gui Rong Li ◽  
Xiang Zhu ◽  
Yu Tao Zhao
Keyword(s):  
Slag System ◽  
Calculation Model ◽  
Slag Basicity ◽  
Mass Action ◽  
Al2o3 Content ◽  
Coexistence Theory ◽  
Slag Structure

According to the coexistence theory of melted slag structure, a calculation model of mass action concentrations for CaO-Al2O3-SiO2 slag system has been established, by which the mass action concentrations of all structure units in CaO-SiO2-Al2O3 systems are calculated. The effects of Al2O3 content and slag basicity on the mass action concentrations are investigated. The results indicate that both basicity and the content of Al2O3 have remarkable effects on mass action concentrations of CaO, 2CaO•SiO2, CaO•SiO2, CaO•Al2O3 and 2CaO•SiO2•Al2O3, etc. Furthermore, the effects of Al2O3 content on mass action concentrations are relevant with slag basicity. The basicity has more influences on mass action concentrations of CaO, CaO•SiO2, 2CaO•SiO2 and 3CaO•SiO2, whereas the basicity has little effect on mass action concentrations of other structure units in CaO-SiO2-Al2O3 system.

Calculation Model of Mass Action Concentrations for CaO-MnO-FeO-SiO2-MgO-Al2O3 Slags Based on the Ion and Molecule Coexistence Theory

2012 ◽  
Vol 476-478 ◽  
pp. 134-138
Author(s):  
Xiao Hong Yang ◽  
Xiao Chun Ma ◽  
Cheng Chuan Wu ◽  
Guo Guang Cheng
Keyword(s):  
Phase Diagrams ◽  
Thermodynamic Model ◽  
Slag System ◽  
Calculation Model ◽  
Mass Action ◽  
Structural Units ◽  
Coexistence Theory ◽  
Slag Structure ◽  
Calculation Results ◽  
Good Agreement

According to the ion and molecule coexistence theory (IMCT) of slag structure and corresponding phase diagrams, a thermodynamic model for calculating mass action concentrations of structural units or ion couples of CaO-MnO-FeO-SiO2-MgO-Al2O3 slags was established. Equilibrium mass action concentrations of each structure unit were gained. And the calculation results of NFeO and NMnO were compared with measured aFeO and aMnO. The comparison shows that the calculated values of NFeO and NMnO are in good agreement with the reported measured values of aFeO and aMnO, so this calculating model could fairly describe the characteristics of the slag system.

Calculation Model of Activity for Slag System of CaO-SiO2-Fe2O3

2012 ◽  
Vol 535-537 ◽  
pp. 2503-2506
Author(s):  
Xiang Zhu ◽  
Hong Ming Wang ◽  
Gui Rong Li ◽  
Yu Tao Zhao
Keyword(s):  
Significant Influence ◽  
Molten Slag ◽  
Slag System ◽  
Calculation Model ◽  
Slag Basicity ◽  
Main Structure ◽  
Fe2o3 Content ◽  
Coexistence Theory ◽  
Maximum Value ◽  
Slag Structure

Based on the coexistence theory of slag structure, the activity model of CaO-SiO2-Fe2O3 ternary slag system was established. The effects of Fe2O3 content and basicity on the activities of CaO and 2CaO•SiO2 were investigated. The structure units of Fe2O3 in the molten slag were discussed. The results indicate the slag basicity has a significant influence on the activities of CaO and 2CaO•SiO2. The activity of CaO increases with increasing slag basicity, while the activity of 2CaO•SiO2 increases with the increasing of slag basicity when the basicity is less than 1.8, which reaches the maximum value when the basicity is 1.8. In another word, when the slag basicity exceeds 1.8, the activity of 2CaO•SiO2 decreases with the increasing of slag basicity. In addition, the activities of CaO and 2CaO•SiO2 can be decreased by Fe2O3. Moreover, when the slag basicity is higher than 2.0, the activity of 2CaO•SiO2 increases slightly with the increasing of Fe2O3 content. The main structure units of Fe2O3 in molten slag are closely related to the slag basicity.

Calculation Model of Mass Action Concentration for CaO-B2O3-SiO2 Slag System

2013 ◽  
Vol 634-638 ◽  
pp. 3114-3117 ◽  
Author(s):  
Hong Ming Wang ◽  
Xiang Zhu ◽  
Gui Rong Li
Keyword(s):  
Slag System ◽  
Calculation Model ◽  
Slag Basicity ◽  
Mass Action ◽  
Coexistence Theory ◽  
B2o3 Content ◽  
Maximum Value ◽  
Slag Structure ◽  
Mass Action Concentration

According to the coexistence theory of melted slag structure, a calculation model of mass action concentrations for CaO-B2O3-SiO2 slag system has been established, by which the mass action concentrations of all structure units in CaO-B2O3-SiO2 systems are calculated. The results indicate that the activities of CaO and 2CaO•SiO2 can be decreased effectively by B2O3. Furthermore, when the slag basicity is higher than 2.0, the activity of 2CaO•SiO2 increases firstly and then decreases with the increasing of B2O3 content. The activity of CaO increases with the increasing of slag basicity. When the basicity is less than 2.2, the activity of 2CaO•SiO2 increases with the increase of slag basicity. Moreover, when the basicity is 2.2, the activity of 2CaO•SiO2 reaches the maximum value. In another word, the activity of 2CaO•SiO2 decreases with the increase of slag basicity on the condition that the slag basicity exceeds 2.2. B2O3 exists in the slag in the form of CaO•B2O3, 2CaO•B2O3 and 3CaO•B2O3.

scholarly journals Effect of TiO2 content in slag on Ti content in molten steel

2021 ◽  
Vol 40 (1) ◽  
pp. 99-107
Author(s):  
Gang Gao ◽  
Xiaofang Shi ◽  
Zhenghai Zhu ◽  
Lizhong Chang
Keyword(s):  
Molten Steel ◽  
Laboratory Experiments ◽  
Calculation Model ◽  
Ladle Slag ◽  
Coexistence Theory ◽  
Industrial Experiments ◽  
Critical Content ◽  
Slag Structure ◽  
Dissolved Aluminum ◽  
Ti Content

Abstract A calculation model of activity for CaO–SiO2–MgO–Al2O3–TiO2 slag is established according to molecular-ion coexistence theory of slag structure to calculate the activities of Al2O3, SiO2, and TiO2 in the slag. The possibility of TiO2 reduction in the slag during refining is analyzed by thermodynamics and verified by laboratory and industrial experiments. Both theoretical analysis and laboratory experimental results show that the content of TiO2 in the ladle slag significantly influences the Ti content in molten steel. When the content of the dissolved aluminum in molten steel is 0.030–0.050%, the TiO2 content in the ladle slag should be controlled below 0.3% to prevent TiO2 reduction. The critical content of TiO2 decreases with an increasing amount of the dissolved aluminum in molten steel. In addition, silicon should be used as a deoxidizer during diffused deoxidization because aluminum as a deoxidizer would lead to the reduction of TiO2. The industrial experiments confirm the results of the laboratory experiments and thermodynamics analysis.

scholarly journals Recovery of zinc from zinc oxide dust containing multiple metal elements by carbothermal reduction

2021 ◽  
pp. 49-49
Author(s):  
F.-G. Lei ◽  
M.-T. Li ◽  
C. Wei ◽  
Z.-G. Deng ◽  
X.-B. Li ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Carbothermal Reduction ◽  
Carbothermic Reduction ◽  
Reduction Process ◽  
Zinc Content ◽  
Holding Time ◽  
Reduction Condition ◽  
Reduction Experiment ◽  
Effects Of Temperature ◽  
Optimal Reduction

A carbothermal reduction process simulating EAF process is used to handle the zinc oxide dust, and the zinc in the dust can be extracted and recovered efficiently. The crude zinc and lead-tin alloy were obtained finally. The effects of temperature, holding time, and reductant dosage on zincvolatilization rate were investigated, and the ?Pelletizing -Calcination-Carbothermic reduction? experiment was conducted. The resultsfound the optimal reduction condition was as follows: the temperature of 1300?C, reductant dosage of 14.04% and holding time of 120 min. After the calcination at 900?C for 120 min, the removal rates of fluorine, chlorine and sulfur in the dust were 98.18%, 96.38% and 28.58% respectively, and the volatilization rate of zinc was 99.83% in reduction process. The zinc content of the crude zinc was 68.48%.

Activity Calculation Model for Oxygen Converter Final Slag

2014 ◽  
Vol 881-883 ◽  
pp. 1784-1789
Author(s):  
Ting Wang ◽  
Wen Dong Qiu ◽  
Hua Zhi Gu ◽  
Wei Zhao
Keyword(s):  
Mass Fraction ◽  
Equilibrium Distribution ◽  
Oxygen Converter ◽  
Converter Slag ◽  
Slag System ◽  
Calculation Model ◽  
Thermodynamics Analysis ◽  
Final Slag ◽  
Coexistence Theory ◽  
Maximum Value

In this paper the activity calculation model for SiO2-Al2O3-CaO-MgO-FeO-MnO slag system has been established according to the molecule-ion coexistence theory. From that the activity of each component in the converter slag at steelmaking temperature can be calculated and then provides the basis for analyzing the equilibrium distribution of element between slag and steel, as well as thermodynamics analysis related to the activity.With the increasing of FeO mass fraction, the activity of 3CaO.SiO2 shows a significant decreasing trend and the activity of MnO.SiO2 and 2MnO.SiO2 increases slowly. The activity of 3CaO.SiO2 increases at first then decreases, with the increasing of basicity. When the basicity w(CaO)/w(SiO2)=3, the activity of 3CaO.SiO2 reaches its maximum value. The activities of MnO.SiO2 and 2MnO.SiO2 decrease gradually.

Research on Activities of CaO-SiO2-B2O3 (Al2O3, Fe2O3) Slag System

2012 ◽  
Vol 217-219 ◽  
pp. 492-495 ◽  
Author(s):  
Hong Ming Wang ◽  
Gui Rong Li ◽  
Xiang Zhu ◽  
Yu Tao Zhao
Keyword(s):  
Mathematical Model ◽  
Slag System ◽  
Coexistence Theory ◽  
Slag Structure

A mathematical model on activities of CaO-based slag system has been established on the bases of ion-molecule coexistence theory of melted slag structure. The activities of CaO-SiO2-B2O3 (Al2O3, Fe2O3) systems are calculated. The effects of the content of B2O3, Al2O3 and Fe2O3 on activities are analyzed. The results indicate that the activities of CaO and 2CaO•SiO2 are decreased with the increases of B2O3, Al2O3 and Fe2O3. The effect of B2O3 is most remarkable. Moreover, the activity of CaO•SiO2 can be enhanced with increasing the contents of B2O3, Al2O3 and Fe2O3 respectively. These effects of Al2O3 and Fe2O3 are very similar, whereas the effect of B2O3 is most significant. As a conclusion, B2O3 is most effective to inhibit the formation of 2CaO•SiO2 as well as to promote the dissolution of lime.

Phase Behaviors of Talc Minerals in Carbothermal Reduction Process

2012 ◽  
Vol 512-515 ◽  
pp. 123-126
Author(s):  
Wen Juan Li ◽  
Zhao Hui Huang ◽  
Zi He Pan ◽  
Yan Gai Liu ◽  
Ming Hao Fang
Keyword(s):  
Silicon Carbide ◽  
Carbothermal Reduction ◽  
Acid Leaching ◽  
Reduction Process ◽  
Magnesium Silicate ◽  
Raw Material ◽  
Carbon Powder ◽  
Carbon Addition ◽  
Effects Of Temperature ◽  
Phase Behaviors

In this paper, we focus on the phase behaviors of talc minerals by carbothermal reduction (CR) method. The effects of temperature and carbon addition are both discussed in our work. In the experiment, acid-leaching talc was employed as raw material, carbon coke powders were adopted as reducing agent. The XRD results show that: When acid-leaching talc was used as raw material, quartz and few enstatite can be obtained at 1300 °C, with the temperature increasing, the diffraction intensities of enstatite increased. At 1550 °C, enstatite transformed to magnesium silicate and obvious β-SiC can be detected. At 1600 °C, the main phases in the final product are magnesium silicate and β-SiC. The SEM results reveal that the preferred, as-fabricated silicon carbide has morphology of irregular shape. Relatively pure β-SiC can be obtained by using acid-leaching talc mixed together with excess 50% of theoretical quantity of carbon powder sintered at 1550 °C for 4 h.

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