| abstract |
A method is provided for the hydrometallurgical recovery of metal values from metal sources containing more than one metal such as antimony, lead, copper, zinc, bismuth, tin, cadmium and other metals by leaching the metal containing source with a ferric fluoborate/fluoboric acid solution to provide a metal containing leach solution. The leach solution is extracted with organic extractants, ion exchange resins and the like to provide a loaded extract and a raffinate which contains fluoboric acid produced in the extraction step. The fluoboric acid concentration is controlled (reduced) in the raffinate by adding to the raffinate a metal oxide of a metal in the raffinate to form an acid adjusted raffinate. The acid adjusted raffinate is then electrowon or otherwise treated to form the desired metal and to provide a ferric fluoborate solution which is recycled for leaching additional metal containing material. When the metal containing material is a copper bearing material, a copper containing raffinate is treated with copper oxide to control the fluoboric acid in the raffinate. Likewise, when the metal containing material is a lead or zinc bearing material, lead oxide and zinc oxide, respectively, would be used to control formed fluoboric acid in the lead or zinc containing raffinate. |