还原浸出炼锌系统提升铜回收率的生产实践

Production practice to improve Cu recovery in zinc hydrometallurgy system

云锡文山锌铟冶炼有限公司采用赤铁矿除铁结合SO_(2)还原浸出进行湿法炼锌,生产前期铜回收率一直偏低。公司针对该问题对铜在生产系统中的行为和平衡情况进行了分析,发现SO_(2)还原浸出段铜浸出率低是造成系统铜回收率低的主要原因。通过在SO_(2)还原浸出段提高反应温度10~15℃、增加浸出时间30~45 min、提高初始酸度至20~30 g/L,可提高铜浸出率11%左右;合理控制SO_(2)气体的通入量,一般以溶液Fe^(3+)含量的1.2倍为宜,可避免SO_(2)气体通入过量导致铜被还原沉淀,减少浸出渣带走铜量。采取以上措施以后,最终提升系统铜回收率10%左右,铜回收率达到93%。

Yunxi Wenshan Zinc Indium Smelting Co.,Ltd adopted hematite Fe removal combined with SO_(2)reduction leaching for Zinc hydrometallurgy.Cu recovery had been relatively low in early production.To address the problem,the Company analyzed the behaviors and balance status of Cu in the production system,and found that low Cu leaching rate in SO_(2)reduction leaching section was the major cause for the low Cu recovery in the system.By increasing the reaction temperature by 10-15℃,leaching time by 30-45 min and initial acidity to 20-30 g/L in SO_(2)reduction leaching section,Cu leaching rate can be increased by about 11%;in addition,by controlling the volume of SO_(2)input at an appropriate level,generally 1.2 times the content of Fe^(3+)in the solution,Cu precipitation caused by excessive SO_(2)input can be avoided,and the loss of Cu into the leaching slag can be reduced.With the above measures,the final Cu recovery rate of the system is improved by about 10%up to 93%.