Processing of oxidised and sulphide copper ore mixtures: Preliminary study

The leaching of a copper oxide and sulphide copper ores have been largely reported. Many investigations on the leachability on different copper sulphide ores from different countries have been conducted and optima working conditions recommended. The present work present is a preliminary study on a mixture of sulphides and oxides copper ores from Kamoto mine in the Katanga province in the Democratic Republic of Congo. Initially, oxides copper ores were mined at Kamoto and the leaching process was efficiently conducted. With the mine deepening a mixture of oxides and sulphides copper is mined. This rendered the leaching of the mixture becoming difficult thus the need to find new avenues of leaching. In this work, three categories of leaching tests were conducted. In category A, the oxide and sulphide ores were separately leached with sulphuric acid where the particle size influence was investigated and the best size identified as well as the optimum pH value. In category B, the sulphide ore was leached with sulphuric acid in conjunction with hydrogen peroxide. An improvement in copper and cobalt dissolution was noticeable. In category C, a mixture of oxide and sulphide ores, in different proportions; was dissolved with sulphuric acid with the addition of hydrogen peroxide. The best proportion was found and used to identify the optimum pH value with pH varied from 1.5 to 2.5.