辽宁某氰化尾渣中铁、铅综合回收试验研究

Test Study on Comprehensive Recovery of Iron and Lead from Cyanide Residue in Liaoning

辽宁某黄金冶炼企业氰化尾渣中铁、铅含量分别为35.93%、3.88%,具有一定的综合回收价值。针对此尾渣开展了还原焙烧—熔分法回收铁和铅的试验研究,重点考察了焙烧温度、焙烧时间、还原剂用量和添加剂用量对铁金属化率和铅挥发率的影响。结果表明,在焙烧温度为1250℃、焙烧时间为60 min、焦粉用量为20%、CaO用量为25%的条件下,氰化尾渣的铁金属化率和铅挥发率分别达到99.85%和95.92%;X射线衍射和扫描电镜分析结果表明,添加剂CaO可以促进焙烧过程中铁还原、铅挥发和金属铁颗粒的聚集长大,并且具有一定的脱硫作用。将焙烧渣在1600℃下熔分1 h,可获得TFe品位达90.02%、硫含量为0.016%、铁回收率为88.92%的铁锭。熔分渣的各项毒性浸出指标远低于控制标准,实现了氰化尾渣的无害化、资源化利用。

The cyanide residue from a gold smelting enterprise in Liaoning province contains the iron of 35.93%and the lead of 3.88%,which has certain comprehensive recycling value.An experimental study was carried out on the recovery of iron and lead for the residue by reduction roasting and fusion method.The influence of roasting temperature,roasting time,reducing agent dosage and additive dosage on the iron metallization rate and lead volatilization rate were investigated.The results showed that the metallization rate of iron and volatilization rate of lead reached 99.85%and 95.92%respectively with the roasting temperature of 1250℃,roasting time of 60 min,coke powder dosage of 20%and CaO dosage of 25%.Xray diffraction and scanning electron microscope analysis results showed that the additive calcium oxide can promote the reduction of iron,volatilization of lead and aggregation of metal iron particles in the roasting process,and has a certain effect of desulfurization.Iron ingots with the iron grade of 90.02%,sulfur contents of 0.016%and iron recovery rate of 88.92%were obtained by melting the roasting slag at 1600℃for 1 h.The toxicity leaching indexes of the roasting slag were far lower than the National standard.The purpose of harmless and resource utilization of cyanide residue was realized.