Chapter 28 - Cobalt – Occurrence, Production, Use and Price

Abstract

This chapter discusses the occurrence, extraction methods, uses and price of cobalt. Out of about 60,000 tonnes of cobalt mined per year, about half originates from copper-cobalt ores mined in the Democratic Republic of Congo and Zambia. The remainder comes equally from sulfide ores containing pentlandite and lateritic ores containing goethite. Extraction from sulfide ores is done using floatation, sulfide smelting to converter matte and later refining of the matte to recover cobalt. The extraction from lateritic ores is by leaching, sulfide precipitation, re-dissolution, cobalt solvent extraction and then electrowinning or hydrogen reduction. Some of the deposits of ores of the Democratic Republic of Congo and Zambia have been extensively weathered by rain, air and vegetative acids and cobalt is extracted by reductive leaching in sulfuric acid, solvent extraction, and purification. Cobalt is used as chemicals for rechargeable batteries, high-temperature superalloys, cutting tools, pigments, magnets, etc. As cheaply mined cobalt ore is available from the Democratic Republic of Congo, the average price of cobalt has remained stable. It was approximately $40,000 per tonne in June 2010. The Democratic Republic of Congo is by far the biggest miner and China is the biggest refiner. This increase in production is driven mainly by increased cobalt use in developing countries, particularly China.