低品位硫铜钴矿生物浸出液中铜的分离

Separation and Recovery of Copper from Bio-leaching Solution of Low-Grade Carrollite

生物氧化法处理低品位铜钴硫化矿时,浸出液常含有高浓度的铁、低浓度的钴及一定量的铜,因此在回收钴前对其中的铜进行选择性分离提取,并避免钴的损失.采用萃取剂LIX984N选择性分离低品位硫铜钴矿生物浸出液中的铜.结果表明,当采用LIX984N体积分数为25%的有机相,在环境温度为35℃,相比为1∶1时,混合时间为5 min,平衡pH值为1.25的条件下,可达到99.4%的铜萃取率.该条件下铁夹带仅为4.03%,钴共萃率0.849%.对负载有机相采用中性水在相比1∶1的条件下洗涤,使钴和铁夹带分别降至0.008%和0.766%.洗涤后,负载有机相采用200 g/L硫酸水溶液反萃,当有机相与水相体积比为1∶1时,经过2级逆流反萃时,铜反萃率达到98.13%.

Biological leaching solution of low-grade carrollite often contains a high concentrations of iron, a low concentrations of cobalt and a amount of copper when using the biological oxidation method. So the selective separation of copper was carded out before the recovery of cobalt to avoid the loss of cobalt. LIX984N as an extractant was used to selectively separated and extracted copper from the low-grade carrollite biological leaching solution. The results showed that, when the volume fraction of LIX984N is 25% , ambient temperature 35 ℃, O/A 1 ： 1, mixing time 5 min and equilibrium pH 1.25, the extraction rate of copper is 99.4%. Under the same condition, the extraction rates of the iron of entrainment and the cobalt was only 4. 03% and 0. 849% respectively. Loaded organic phase was washed by pure water under O/A 1 ： 1, the extraction rates of the cobalt and iron of entrainment decreased to 0. 008% and 0. 766% respectively. After washing, loaded organic phase was stripped using sulfuric acid solution with concentration of 200 g/L. When O/A was 1 ： 1, after two countercurrent stripping, the copper stripping rate was 98.13%.