A Thermodynamic Model of Phosphorus Distribution Ratio between CaO-SiO2-MgO-FeO-Fe2O3-MnO-Al2O3-P2O5 Slags and Molten Steel during a Top–Bottom Combined Blown Converter Steelmaking Process Based on the Ion and Molecule Coexistence Theory

2011 ◽  
Vol 42 (4) ◽  
pp. 738-770 ◽  
Author(s):  
Xue-Min Yang ◽  
Jian-Ping Duan ◽  
Cheng-Bin Shi ◽  
Meng Zhang ◽  
Yong-Liang Zhang ◽  
...  
Keyword(s):  
Molten Steel ◽  
Distribution Ratio ◽  
Thermodynamic Model ◽  
Converter Steelmaking ◽  
Steelmaking Process ◽  
Phosphorus Distribution ◽  
Coexistence Theory ◽  
Phosphorus Distribution Ratio

Thermodynamic Model of Calculation of Sulfur Distribution Ratio between B2O3-Containing Slag and Molten Steel

2014 ◽  
Vol 633-634 ◽  
pp. 188-191
Author(s):  
Xiang Zhu ◽  
Yang Li ◽  
Xiao Jian Fan ◽  
Hong Ming Wang ◽  
Gui Rong Li
Keyword(s):  
Molten Steel ◽  
Distribution Ratio ◽  
Thermodynamic Model ◽  
Slag Basicity ◽  
Sulfur Distribution ◽  
Coexistence Theory ◽  
Sulfur Distribution Ratio

A thermodynamic model of calculation of sulfur distribution ratio between B2O3-containing slag and molten steel has been developed on the basis of the ion and molecule coexistence theory. Based on the model, the effects of B2O3 content and slag basicity on the sulfur distribution ratio in 1873K were investigated respectively. The results indicate that the sulfur distribution ratio decreased with increasing the content of B2O3, and when the content of B2O3 exceeds 6%, the sulfur distribution ratio was lower than 2.0. Therefore, in order to ensure the desulphurization ability of slag, the content of B2O3 should be controlled at about 6%. Moreover the sulfur distribution ratio can be increased by increasing the slag basicity.

Thermodynamic Modelling of Phosphorus in Steelmaking Slags

2013 ◽  
Vol 32 (3) ◽  
pp. 237-246 ◽  
Author(s):  
Chunlin Chen ◽  
Ling Zhang ◽  
Jean Lehmann
Keyword(s):  
Liquid Iron ◽  
Distribution Ratio ◽  
Operating Conditions ◽  
Model Parameters ◽  
Steelmaking Slag ◽  
Maximum Point ◽  
Phosphorus Distribution ◽  
Steelmaking Slags ◽  
Model Database ◽  
Phosphorus Distribution Ratio

AbstractThe published phase diagrams of some key P2O5-containing systems which are relevant to the steelmaking slag and the available experimental data on phosphorus partitioning between liquid iron and slags consisting of SiO2-Al2O3-Fe2O3-FeO-MnO-MgO-CaO-Na2O have been reviewed and assessed. A set of data under carefully controlled experimental conditions, which was considered to be more reliable based on the assessment, was selected for optimising the generalised central atom (GCA) model parameters of phosphorus-containing slag systems. The developed model database is proved to be able to represent the liquidus temperature of some key P2O5-containing systems and the phosphorus distribution ratio between the steelmaking slags and liquid iron reasonably well. With the developed GCA model database, the dephosphorization reaction in the steelmaking process was modelled under various operating conditions such as slag chemistry and temperature. The results show that the phosphorus distribution ratio between the slags and liquid iron displays a maximum point with variation of the FeOx content in the slag. It also shows that the phosphorus deportment to the slag is favored by decreasing the operating temperature and MgO content, and increasing the CaO/SiO2 ratio in the slag. Comparison with the model of the phosphorus distribution data from a commercial BOS furnace shows that operating conditions do not permit to reach P equilibrium contents. The dis-equilibrium degree of P was found to be increased with increasing slag viscosities.

scholarly journals Mechanism of Phosphorus Enrichment in Dephosphorization Slag Produced Using the Technology of Integrating Dephosphorization and Decarburization

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 216
Author(s):  
Haimeng Xue ◽  
Jie Li ◽  
Yunjin Xia ◽  
Yong Wan ◽  
Liangjun Chen ◽  
...  
Keyword(s):  
Solid Solution ◽  
Distribution Ratio ◽  
Thermodynamic Calculation ◽  
Slag Composition ◽  
Slag Basicity ◽  
Hot Metal ◽  
Phosphorus Enrichment ◽  
Phosphorus Distribution ◽  
Dephosphorization Slag ◽  
Phosphorus Distribution Ratio

In order to better understand and develop the technology of integrating dephosphorization and decarburization in a single converter (abbreviated as IDDSC), the relevant thermodynamic issues were discussed by calculation. Based on the thermodynamic calculation, the bridges between the phosphorus distribution ratio, temperature, and slag composition were constructed. Besides, the connections between the dephosphorization behavior and the microstructure of slag were also established by investigating four heats of hot metal smelt using IDDSC technology. As a result, the mechanism of phosphorus enrichment in the dephosphorization slag was revealed. Also, the results show that the dephosphorization efficiency increases gradually with increasing slag basicity. While the dephosphorization efficiency increases first and then decreases with the increase of FeO content in slag. There is a competition relationship between P2O5 and FeO in reacting with CaO and SiO2. When CaO/FeO is relatively high, not enough FeO is provided. Thus P2O5 is in priority to react with CaO and SiO2 through [3n + 2](CaO) + 2SiO2 + n(P2O5) = n(3CaO·P2O5)-2CaO·SiO2(s), generating P2O5-rich nC2S-C3P solid solution which promotes the removal of [P] from the hot metal. When CaO/FeO is relatively low, FeO competes over P2O5 in reacting with CaO and SiO2 through a(CaO) + b(SiO2) + c(FeO) = aCaO·bSiO2·cFeO(s), generating CaFeSiO4 instead of P2O5-rich solid solution. As a consequence, the slag with low CaO/FeO shows a poor dephosphorization ability.

scholarly journals Oxidizability characterization of slag system on the thermodynamic model of superalloy desulfurization

2020 ◽  
Vol 39 (1) ◽  
pp. 405-416
Author(s):  
Wanming Li ◽  
Yulei Sun ◽  
Shaopeng Wu ◽  
Ximin Zang
Keyword(s):  
Distribution Ratio ◽  
Thermodynamic Model ◽  
Inconel 718 ◽  
Slag System ◽  
Balance Model ◽  
Characterization Methods ◽  
Coexistence Theory ◽  
Decisive Influence ◽  
Inconel 718 Superalloy

AbstractThe oxidizability characterization method of slag system has a decisive influence on the accuracy of the desulfurization model. By carrying out the balance experiments of melting system composed of CaF2–CaO–Al2O3–SiO2–TiO2–MgO–FeO slag system and Inconel 718 superalloy, the influence of Al2O3 and FeO on desulfurization distribution ratio at 1,773 K was studied. Based on the ion and molecule coexistence theory in slag, the effects of three oxidizability characterization methods, [Fe]–[O] balance, [Al]–[O] balance, and [Fe]–[Al]–[O] balance, on the accuracy of desulfurization thermodynamic model were studied. The results show that the effect of FeO on desulfurization distribution ratio is more significant than that of Al2O3 when the FeO content in slag is greater than 0.014%. When the FeO content in the slag is less than 0.014%, the effect of Al2O3 on the slag oxidizability will be greater than that of FeO. The calculated value of [Fe]–[Al]–[O] balance model is closer to the experimental-measured value compared to [Fe]–[O] balance model and [Al]–[O] balance model alone at 1,923 K.

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