炉渣组分对CaO-MgO-Al2O3-Si2O-Cr2O3-FeO-TiO2渣系中铬尖晶石相析出影响的热力学

Thermodynamics of the effects of slag compositions on the precipitation of chromium spinel in CaO-MgO-Al2O3-Si2O-Cr2O3-FeO-TiO2 slag system

根据熔体的非平衡凝固理论,采用热力学数据库Factsage7.1模拟计算研究了不同碱度、MgO以及FeO的质量百分数对不锈钢渣微晶玻璃的基础玻璃成分CaO-MgO-Al2O3-SiO2-Cr2O3-FeO-TiO2体系中尖晶石矿相开始析出温度、种类及其析出量的影响规律。计算结果表明,碱度为0.47时,析出矿物相主要包括透辉石、钙长石以及尖晶石等相,其中透辉石为主要物相。尖晶石相为高温析出相,主要由MgCr2O4和FeCr2O4组成。在不同碱度条件下,总尖晶石开始析晶温度随着MgO质量百分数的增加而增加。当w(C)/w(S)为0.47,氧化镁的质量百分数小于10.52%时,镁铬尖晶石和铁铬尖晶石的析出量随着氧化镁质量百分数的增加而增加。氧化镁的质量百分数大于10.52%时,随着氧化镁质量百分数的增加,镁铬尖晶石析出量增加,而铁铬尖晶石的析出则逐渐减少。FeO的质量百分数小于7.57%时,镁铬尖晶石和铁铬尖晶石的析出量随着氧化铁含量的增加而增加,FeO的质量百分数大于7.57%以后,随着氧化铁含量的增加,镁铬尖晶石析出量减少,铁铬尖晶石析出量增加。

According to the non-equilibrium solidification theory of the melt,the effects of basicity,MgO and FeO mass percentages on the initial precipitation temperature,precipitation amount and chemical compositions of spinel phase in CaO-MgO-Al2O3-SiO2-Cr2O3-FeO-TiO2 system,a basic component of the glass-ceramics prepared by stainless steel slag have been studied by using the thermodynamic database of Factsage 7.1.The results show that the mineral phases precipitated in the process of non-equilibrium cooling and solidification mainly include diopside,anorthite and spinel phases,among which diopside is the main phase.The spinel phase,precipitated at high temperature,is mainly composed of MgCr2O4 and FeCr2O4.At different degrees of basicity,the initial crystallization temperature of spinel rises with the increase of the mass percentage of MgO.When the w(C)/w(S)is 0.47 and the mass percentage of MgO is less than 10.52%,the precipitation amounts of magnesium-chromium spinel and iron-chromium spinel increase with the increase of the mass percentage of MgO.When the w(C)/w(S)is 0.47 and the mass percentage of MgO is over 10.52%,the precipitation amount of magnesium-chromium spinel increases while that of iron-chrome spinel gradually decreases.When the mass percentage of FeO is less than 7.57%,the precipitation amount of magnesium-chromium spinel and iron-chrome spinel increases with the increase of the mass percentage of FeO.When the mass percentage of FeO exceeds 7.57%,the precipitation amount of the magnesium-chromium spinel decreases and that of iron-chromium spinel increases with the increase of the mass percentage of FeO.