Experimental Comparison of Processes for Recovery of Copper and Zinc from Mine Water

摘要

The development of environmentally and economically viable processes for recycling mineral containing effluents is an important modern-day challenge. When treating mine waters we should aim at selective recovery of valuable components in the form of products whose matrix is similar to that of ore beneficiation concentrates or other components of the melting furnace charge. It is possible to efficiently treat mine waters by using processes comprising both conventional water treatment methods and hydrometallurgical solution treatment techniques. We have made an experimental comparison of processes of recovery of copper and zinc from hard sulphate waters of some copper mines located in the Urals. Effluent waters from different deposits vary in mineralization levels, hardness, iron saturation, the ratio of ion concentrations of iron with different valences, and concentrations of chalcophile metals. We have used a combination of hydrolytic and sulphide precipitation, cementation and galvanocoagulation, and described the experiment and parameters of the processes under investigation. The copper and zinc recovery rate is 45-99% depending on the method used. A significant factor impacting the selective recovery and weight content of metals in precipitates obtained by different methods is the ratio of concentrations of such metals in mine water. We have determined reasonably achievable values of precipitate quality in terms of the combined weight content/recovery rate criterion. We have also presented the phase composition of the precipitates obtained and analysed the usability of such products in production operations. We have further set out our classification of products of recycling effluent waters based on metals' weight contents and their possible uses in mining and metallurgical production. The paper lists key features of the mine water treatment processes and presents a comparison of technological and economic aspects of such processes based on the use of modular treatment facilities.