溶剂萃取法应用于混合铜锌原料的处理

Solvent extraction applied to mixed copper and zinc bearing materials

溶剂萃取法(SX)精炼铜产品的产量已占全球产量的20%以上。近年来该技术已变得越来普及。作为处理铜矿石和铜精矿的新的湿法冶金设计方案,在智利、美国等国家,该方案正在被评估或已经在过去的几年中付诸实施。萃取工厂具有低投入、低运营成本和操作简单、可生产高品质电解金属产品的特点,该类工厂设置在矿场附近,使得溶剂萃取工艺在中小规模生产中具有经济性、适应性和可行性,而这种规模不适于采用传统熔炼工艺。在某些情况下,选择得到高度纯盐类化合物可能比生产金属产品成本更低。由于商业上的成功,2003年以来年产15万t锌、专门处理原生和再生物料的纳米比亚Skorpion锌联合冶炼厂,目前正利用ZINCEX^(TM)溶剂萃取技术建设一个新的锌扩产项目。铜萃取和锌萃取是成熟和完善的商业技术。对于处理混合或多金属铜锌矿石和再生物料的新的采矿和冶金工程,现在正是考虑应用该技术的好时机。本论文提供了溶剂萃取技术在以下两个工业生产应用中的设计特点和技术优势:(1)氧化铜/锌多金属矿堆浸以回收高纯度阴极铜锌;(2)处理烟尘和铜熔炼炉的电收尘固体颗粒以回收铜锌并除去某些杂质,例如砷。在这两个项目中,该技术评估结果都是积极的,显示出依靠溶剂萃取技术回收这些金属具有明显的技术优势和潜在的经济效益。

Refined copper produced by means of solvent extraction（SX） accounts for over 20%of the world production and that technique has become more popular recently as new hydrometallurgical projects dealing with primary copper ores and concentrates are under evaluation or have been implemented in the last years in Chile, USA,etc. The low capital and operating costs of SX plants together with the easy operation and the production of top quality electrolytic metals close to the mine site make the economics of the SX processes very attractive,being suitable and feasible in the range of small to medium capacities,where conventional smelting process is not applicable. In some cases,the alternative of obtaining extremely pure salts may be cheaper than metals production. Thanks to the commercial success of the Skorpion Zinc integrated refinery in Namibia,producing 150 000 t/y SHG Zn since 2003,a significant expansion of new zinc projects focused on primary and secondary materials is currently underway based on the application of the ZINCEX^（TM） solvent extraction technology. Copper SX and zinc SX are mature and well established commercial technologies.Therefore,now is the right time to afford new mining and metallurgical projects dealing with mixed or polymetallic copper and zinc ores and secondary materials.That way,this paper presents relevant design features and technical advances of two industrial projects based on SX applications：（1） Heap leaching of oxidised copper/zinc polymetallic ores to recover both metals in form of the maximum purity cathodes;（2） Processing of flue dusts and electrofilter solid particles from copper smelters to recycle copper and zinc and rejecting some impurities like arsenic.The preliminary evaluation results have been very positive in both projects,showing clearly the technical advantages and the potential profitability to recover those metals by means of SX techniques.