转炉钢渣气化脱磷反应的热力学分析及试验

转炉渣在钢铁厂内部循环使用是最便捷的钢渣二次利用途径,但目前循环利用量甚少,主要是因为钢渣中磷元素含量较高,在烧结过程中难以去除,烧结矿中的磷又经过高炉冶炼几乎全部进入铁水,造成高炉内的磷富集现象,同时又会加重炼钢过程的脱磷负担.采用Factsage 6.2分别对不添加SiO2和添加SiO2条件下钢渣气化脱磷反应的开始温度进行了热力学计算,初步探明了气化脱磷反应的温度、压力条件;在微波加热条件下将纯试剂Ca3(PO4)2与C在1 100℃、103 Pa条件下进行气化脱磷试验,通过检测反应产物验证了气化脱磷反应的可能性;并将钢渣与焦粉在同样条件下进行气化脱磷试验,保温30 min,气化脱磷率达31％.研究结果探明了钢渣气化脱磷反应的热力学条件,为实现转炉渣在钢铁企业内部的循环利用提供了理论依据.

Thermodynamic analysis and experiment on gasification dephosphorization reaction of converter slag

It is a convenient way of recycle utilization of converter slag in steel plant, but the converter slag is rarely used as iron- smelting raw material,because it contains high phosphorus element, which is difficult to be removed in sintering process. The phosphorus in sinter will enter into molten iron and lead to phosphorus enrichment in the process of blast furnace smelting, at the same time, it will aggravate the burden of dephosphorization during steel- making. Under the condition of different pressure, series of thermodynamic calculations were performed using the Factsage6??2 to determine the beginning temperature of dephosphorus reaction for converter slag containing SiO2 and containing no SiO2?? Pure Ca3(PO4)2 and C were fully mixed to react with each other at the condition of 1100??, 103Pa and microvave heating, and the possibility of the dephosphorization reaction was verified through detection of the reaction products. Furthermore, the gasification dephosphorization rate, under the same conditions, reached 31% after 30 min.The results make clear the thermodynamic conditions of gasification dephosphorization, and provide a theoretical basis for achieving the recycling of converter slag in iron and steel enterprises.