含砷铜渣预脱砷过程的热力学分析

采用HSC Chemistry 6.0 热力学分析软件研究了惰性气氛下焙烧温度对含砷贫化铜渣在预脱砷过程中砷平衡组成的影响, 并通过实验进行了验证。结果表明：在惰性气氛下, 升高温度可促进硫化砷的分解, 而砷酸盐的稳定性较好, 不能通过高温分解脱除。在温度低于500 ℃时, 固态硫化砷物相和氧化物不发生分解; 温度超过500 ℃后, As₂S₃、As₄S₄率先发生气化反应; 温度超过900 ℃后, 硫化砷开始发生分解。对于惰性气氛下铜渣的预脱砷, 实验结果与热力学分析吻合较好。

Thermodynamics of Arsenic Removal from Arsenic-bearing Copper Slag

The effect of roasting temperature at N2 atmosphere on the equilibrium of arsenic during the process of pre-removal of arsenic from the arsenic-bearing copper slag was investigated with HSC Chemistry 6.0 thermodynamic analysis software. And the obtained data were verified by some experiments. It is found that under an inert atmosphere, an elevated temperature can promote the decomposition of arsenic sulfide, but arsenate with good stability can not be removed by pyrolysis. At temperatures below 500 ℃, decomposition of solid-phase arsenic sulfide and oxide does not occur. While at the temperature over 500 ℃, gasification reactions firstly occur for As₂S₃ and As₄S₄; and at the temperature more than 900 ℃, arsenic sulfide begin to be decomposed. As for pre-removal of arsenic from copper slag in an inert atmosphere, thermodynamic analysis data are in good consistent with that experiment results.