Method for producing copper in hydrometallurgical process

摘要

The invention relates to a method for producing copper in a hydrometallurgical process from copper-bearing raw materials, such as sulfidic concentrates. The concentrate is leached in a leaching stage of several steps into a chloride-based solution. The copper-bearing solution obtained from this leaching is subjected to reduction and solution purification, whereafter the copper contained in the solution is precipitated as copper oxidule by means of alkali hydroxide. The alkali chloride solution formed in the production of copper oxidule is fed into chloride alkali electrolysis, where it is regenerated back into alkali hydroxide. The hydrogen generated in the electrolysis is used in the reduction of copper oxidule and in other reduction stages of the process. The formed chlorine is used in the leaching of the raw material. When necessary, the reduced copper that is in a granular or pulverous form is further subjected to melting and casting in order to produce commercial-grade copper.