砷铁渣中砷酸铁的热力学分析及热分解试验

利用铁盐法处理某铅冶炼工业含砷废水,得到砷质量分数为10%的砷铁渣,物相分析表明砷与铁在渣中以砷酸铁的形态存在。据热力学分析,砷酸铁化合物在1600℃以下不会热分解,表明其热力学性质稳定;而在有添加剂碳的情况下,砷酸铁的热分解温度大大降低。试验结果表明:在1200℃条件下,静态焙烧5h,砷酸铁砷的挥发率在90%以上,铁富集10%以上。

Thermodynamic Analysis and Thermal Decomposition Experiments of Arsenic Slag Iron Arsenate

Treatment of a lead smelting industry arsenic wastewater by using ferric method,the arsenic content of about 10% arsenic slag was obtained. The phase analysis indicated that the existences of arsenic and iron in the slag are in the form of ferric arsenate. According to thermodynamic analysis,iron arsenate compound will not be thermally decomposed below 1600℃,indicating that it is thermodynamically stable; in the case of carbon additives,the thermal decomposition temperature of iron arsenate greatly reduced. Experimental studies showed that at 1200℃,static roasting for 5h,iron arsenate arsenic volatilization rates would be reached above 90%,more than 10% iron would be enriched.