The Removal of Radiation and Other Impurities from Copper Sulphide Concentrates

High grade, copper sulphide concentrates, (typically greater than about 25% w/w Cu), are commonly treated via pyrometallurgical routes, whereas hydrometallurgical routes are typically favoured for lower grade or impurity-bearing concentrates. The processing routes for the treatment of copper concentrates can also be influenced by the presence of minor valuable metals such as silver, gold, uranium, palladium and platinum, as well as deleterious metals such as nickel, cobalt, lead and zinc. Many copper iron sulphide concentrates contain radioactive uranium and its progeny. Other elements such as zinc, nickel, cobalt and aluminium also add to the impurity load. This paper summarizes a process that has been successfully demonstrated as being able to remove very significant levels of the original radioactivity, while at the same time upgrading the concentrate so that it attracts reduced transport and treatment costs at smelters. The upgraded concentrates have demonstrated that they satisfy the IAEA Regulations for the Safe Transport of Radioactive Material (2012) for the transport, trade and processing thereof.