不锈钢渣凝固过程中物相转变的热力学分析

采用热力学软件FactSage6.2,研究不锈钢渣凝固过程中的物相转变规律.结果表明:降低碱度和添加Al₂O₃含量均能降低硅酸二钙的析出温度,抑制硅酸二钙的产生,并促进黄长石相的生成.不锈钢渣中尖晶石相的含Cr量随着碱度的降低而增加,当碱度从1.6降到1.0时,Cr质量分数从24.93%增加到48.27%,同时凝固过程液态渣中的铬元素含量随着碱度的降低也有所减少.添加10%的Al₂O₃,有利于尖晶石相的析出,且随着温度的降低,Al³⁺逐步取代尖晶石中的Cr³⁺,尖晶石相中的Cr质量分数也由30.39%(1500℃)降低至13.88%(1300℃).

Thermodynamic Analysis of Phase Transition in Stainless Steel Slag During Solidification

The phase transition in stainless steel slag during solidification was studied with the thermodynamic software of FactSage 6.2. The results show that the temperature for merwinite and di-calcium silicate to precipitate can be decreased to lower values and the formation of melilite was accelerated with decreasing the basicity and increasing the Al₂O₃ content of the slag. The Cr content in the spinel phase increases obviously with decreasing the slag basicity. When the basicity decreased from 1.6 to 1.0, the Cr content in the spinel phase increased from 24.93% to 48.27%, thus leading to lower chromium content in liquid slag during solidification. When the Al₂O₃ content increased to 10% in the slag,the Al₂O₃ favored the precipitation of spinel phase. The chromium bounded in spinel phase was gradually replaced by aluminum with the lowering of temperature, and the Cr content in the spinel phase decreased from 30.39%(1500℃) to 13.88%(1300℃).