微波碳热还原不锈钢厂电弧炉粉尘的热力学及实验研究

Thermodynamics and experimental study of carbothermic reduction of electric arc furnace dust generated from stainless steel plant by microwave

采用微波加热方法进行碳热还原不锈钢厂电弧炉粉尘,并计算粉尘中金属氧化物的理论开始还原温度。结果表明,微波碳热还原不锈钢厂电弧炉粉尘在热力学上可行。实际测量的粉尘中金属开始还原温度比理论计算值低。微波加热物料过程中形成的热点和电弧可能导致局部高温,有利于碳热还原反应的进行。在900℃下,有部分粉尘被还原,随着温度的升高,粉尘的还原程度增大。还原出来的金属相主要以Fe-Cr-Ni合金的形式存在,且成分分布不均匀,残余相主要以FeCr2O4、Fe3O4、CaSiO3、(Mg,Al)SiO3和CaMgSiO4形式存在。

Electric arc furnace dust from stainless steel plant was carbothermically reduced by microwave,and the beginning reduction temperatures of metal oxide were theoretically calculated.The results show that it is thermodynamically feasible for carbothermic reduction of stainless steel dust by microwave,and the measured reduction temperature of metal oxides in dust is lower than the theoretical calculation values.The existence of hot spot and the generation of arc during heating the mixture by microwave can possibly form local high temperature,and therefore it is conducive to carbothermic reduction reactions.At 900 ℃,parts of dust are reduced.The reduction level of dust increases with the increase of temperature.In addition,the reduced metal phases are mainly in the form of Fe-Cr-Ni alloy with uneven distribution of chemical composition,while the residual phases mainly exist as FeCr2O4,Fe3O4,CaSiO3,（Mg,Al） SiO3 and CaMgSiO4.