基于离子分子共存理论(IMCT)建立了Na2O-TiO2-SiO2-CaO-Al2O3-V2O5-MnO-MgO-FeO九元渣系的结构单元作用浓度模型和渣铁间硫分配比热力学模型，并对模型进行实验验证。通过模型计算出1200℃下渣系主要结构单元组成和渣中Na2O, CaO, MnO, MgO和FeO的活度，发现Na2O的加入可促进渣中低熔点物质的生成，降低渣系熔化性温度，改善脱硫反应的动力学条件；同时随着Na2O加入量的增加，渣中Na2O和CaO的活度增加，进而降低渣中S2?离子活度，强化渣铁间脱硫反应。实验结果表明，增加碱矿比提高了渣铁间硫分配比，有利于铁水深度脱硫，铁水中硫含量可降至0.0005wt%以下，硫分配比的理论计算值与实验结果吻合极好。渣中各碱性氧化物的硫分配比随碱矿比RN/C增加逐渐增大，各碱性氧化物硫分配比大小为Na2O>CaO>MnO>FeO>MgO。本研究将共存理论模型成功应用到九元复杂渣系渣铁间脱硫反应机理研究，为铁水深度脱硫过程的渣系优化提供了理论依据。
尹学杰
,
陈德胜
,
王丽娜
,
赵宏欣
,
甄玉兰
,
齐涛
,
王猛
. Na2O-TiO2-SiO2-CaO-Al2O3-V2O5-MnO-MgO-FeO渣系渣铁间硫分配比热力学模型[J]. 过程工程学报, 2023
, 23(1)
: 124
-135
.
DOI: 10.12034/j.issn.1009-606X.222055
A model for the action concentrations calculation of structural units in Na2O-TiO2-SiO2-CaO-Al2O3-V2O5-MnO-MgO-FeO slags and a thermodynamic model of the sulfur distribution ratio between slag and hot metal have been developed based on the ion-molecule coexistence theory (IMCT), and the model was verified by sodium oxide smelting experiments. The theoretical calculation results showed the composition of the main structural units and the activities of Na2O, CaO, MnO, MgO, and FeO in slag at 1200℃. The formation of compounds with a low melting point can be promoted by the addition of Na2O, meanwhile, the content of substances with high melting points decreases, which led to a decrease in the melting temperature of slag and the improvement of dynamic conditions of desulfurization reaction. Besides, the activities of Na2O and CaO increased with the increase of Na2O, thereby the activity of S2? decreased, and the desulfurization reaction between slag and hot metal can also be enhanced. The experimental results revealed that the sulfur distribution ratio between slag and hot metal improved by the increase in RN/C, which was beneficial to the deep desulfurization process of hot metal, and the sulfur can be removed to less than 0.0005wt%. The theoretical calculation results of the sulfur distribution ratio were in good agreement with the experimental results, which indicated that the sulfur distribution ratio can be well predicted by the model during the sodium oxide smelting process. The sulfur distribution ratios of basic oxide in the slag increased with the RN/C increasing and were ranked as Na2O>CaO>MnO>FeO>MgO. The IMCT was successfully applied to the investigation of the mechanism for the desulfurization reaction process between slag and hot metal in the Na2O-TiO2-SiO2-CaO-Al2O3-V2O5-MnO-MgO-FeO slags, which provided a theoretical basis for the optimization of slags in the deep desulfurization process of hot metal.
