刚果(金)某铜精矿酸浸渣中铜的赋存特征及回收

Mineralogy Characteristics and Recovery of Copper in Acid Leaching Residue of a Copper Concentrate in Democratic Republic of the Congo

刚果(金)地区主要采用湿法炼铜工艺提取铜精矿中的铜,含铜55%~65%的硫化铜精矿经过焙烧和两段酸浸后,酸浸渣中含有3%~10%的铜。以刚果(金)某铜精矿焙砂酸浸渣为研究对象,在对其进行工艺矿物学分析的基础上,采用加压浸出方式回收渣中的铜。结果表明,铜精矿焙砂酸浸渣中的铜主要以硅孔雀石、胆矾和亚铁酸铜的形式存在,三种矿物所含铜占总铜量的96.87%,其中亚铁酸铜为主要难浸矿物;酸浸时,酸用量对铜浸出率影响最大;最佳浸出条件为液固比4 mL/g、酸矿比(硫酸用量与酸浸渣的质量比)65%、浸出时间2 h、浸出温度180℃,对应的铜浸出率为94.52%,渣含铜可由处理前的7.66%降低到0.52%。

The process of wet copper smelting is mainly used to extract copper from copper concentrate in Democratic Republic of the Congo(DRC).After roasting and two-stage acid leaching of copper sulfide concentrate containing 55%-65%copper,the acid leaching residue contains 3%-10%copper.Based on the process mineralogy analysis of calcine acid leaching residue of a copper concentrate in the DRC,pressure leaching method was used to recover copper from the acid leaching residue.The results show that copper in the acid leaching residue of calcine of copper concentrate mainly exists in the form of chrysocollite,chalcanthite and copper ferrite.The copper content of these three minerals accounts for 96.87%of the total copper content,and copper ferrite is the main difficult to leach mineral.During acid leaching,the amount of acid used has the greatest impact on copper leaching rate.The copper leaching rate is 94.52%and copper content in the residue can be reduced from 7.66%before treatment to 0.52%under the optimum leaching conditions including liquid-solid ratio of 4 mL g,acid-ore ratio(the mass ratio of sulfuric acid dosage to acid leaching residue)of 65%,leaching time of two hours,and leaching temperature of 180℃.