真空碳热还原含锌粉尘制备锌热力学模拟研究

Thermodynamic Simulation of Preparation of Zinc by Vacuum Carbothermic Reduction of Zinc-containing Dust

采用FactSage7.2软件模拟研究真空碳热还原高炉、电炉和转底炉粉尘在不同温度、配碳量条件下的热力学行为,分析了不同条件下锌的挥发率。结果表明:以高炉粉尘为实验原料,升高实验温度和增加配碳量有利于粉尘的还原和锌的挥发,在温度为700℃、配碳量为14%条件下锌被完全还原并挥发;以电炉粉尘为实验原料,升高温度和增加配碳量有利于还原的进行,在温度为600℃、配碳量为12%时,锌的挥发率达到最大;以转底炉粉尘为实验原料,在压强为1 Pa、配碳量为14%时,还原温度为500℃,粉尘中锌被完全还原并挥发,继续升高温度至650℃时,少量Zn与S反应生成ZnS,导致锌挥发率降低,继续升高温度会将ZnS重新还原。

The thermodynamic behaviors of dust from blast furnace,electric furnace and rotary hearth furnace treated by vacuum carbothermal reduction under different temperature and carbon dosage were studied using FactSage7.2 software,and the volatilization ratio of zinc under different conditions was analyzed.The results show that the reduction ratio of dust and volatilization ratio of zinc are increased with increasing temperature and carbon content,when blast furnace dust was used as the raw material;The reduction could be improved by increasing the temperature and carbon dosage with electric furnace dust as raw material,the maximum volatilization ratio of zinc was obtained at 600℃and carbon dosage was 12%.Taking converter dust as experimental material,when the pressure was 1 pa and the carbon dosage was 14%,Zn in the dust was completely reduced and volatilized at 500℃.When the temperature rose to 650℃,a small amount of zinc reacted with S to form ZnS,which leaded to the reduction of zinc volatilization ratio.If the temperature continued to rise,ZnS would be reduced again.