Carbon-in-pulp processes in South Africa

Abstract

The carbon-in-pulp (CIP) process is now well established in the South African gold industry, with a total of over 1 million metric tons of material being treated each month in six large plants. This tonnage is derived from ground ore, from filtered pulp, from calcine, and from reclaimed sand-tailings dumps. With this new process and the new large plants, those concerned with CIP are experiencing a learning process, since each new plant presents a different set of problems to be overcome. The knowledge and experience gained from these plants is being shared, and will be of benefit in the design and operation of new plants. The CIP process can be subdivided into the following unit operations: • prescreening at a fine size, • adsorption on carbon, • carbon acid-washing and elution, • carbon reactivation, and • gold electrowinning. Results concerning each of these unit operations, which were obtained from pilot plants and from large-scale CIP plants in South Africa, are presented. The latest developments in each of these areas are summarized.