紫金山含铜酸性废水处理及综合回收有价金属试验研究

Experimental Study on Zijin Mountain copper-containing Acidic Wastewater Treatment and Recovery of Valuable Metals

对紫金山含铜酸性废水,采用石灰预中和-硫氢化钠沉淀、石灰预中和-铁屑置换和低压反渗透膜分离技术进行处理,并综合回收其中的有价金属元素。研究结果表明石灰预中和-硫氢化钠沉淀法产品渣铜品位>60%,铜回收率>94%,出水铜<0.5mg/L;铁屑置换法产品渣铜品位>35%,铜回收率>90%;膜分离技术处理铜回收率≥99%,产水中和后可回用或达标外排,浓缩液可通过萃取-电积工艺回收铜。采用膜分离法处理硐坑水后可将Fe、Al等金属离子转移至浓缩液中,产水中和所需石灰量大幅减少,可极大地减少中和渣浆堆放量,有效减轻矿山库容压力,在提高矿山资源的循环使用率方面具有显著的经济、技术优势。

The technology of lime preneutralization-sodium bisulfide precipitation,lime preneutralization—iron filing replacing and low pressure reverse osmosis membrane was adopted for Zijin mountain copper-containing acid wastewater,among which the valuable elements were also recovered.The results showed that through the method of lime preneutralization-sodium bisulfide precipitation,the copper grade of product slag was more than 60％,the recovery of copper more than 94％ and the effluent copper less than 0.5mg/L.Through the method of iron filing replacing,the copper grade of product slag was more than 35％,the recovery of copper more than 90％.When the technology of membrane separation was adopted,the recovery of copper was more than 99％.Meanwhile,after preneutralization the reuse or zero discharge of the producing water can be realized and through the technology of extraction -electrowinning the copper can be recovered from the concentrated liquid.When the technology of membrane separation was adopted to treat the cave water,the metal ions could be transferred in the concentrated liquid,which could reduce the amount of lime required,the amount of slurry stacked and the pressure on mining capacity.Moreover,it has a significant economic and technical advantages in improving the recycling rate of mining resources.