Journal of the Southern African Institute of Mining and Metallurgy
versão On-line ISSN 2411-9717
versão impressa ISSN 0038-223X
Southern Africa has a history rich in the pyrometallurgical processing of ores. Two of the alloys produced are high-carbon ferromanganese (74-83 per cent Mn) and silicomanganese (59-67 per cent Mn and 14-31 per cent Si). The largest land-based manganese ore deposit in the world is based in the Northern Cape Province of South Africa. In 2010, 6.3 Mt of ore from the deposit was exported, mainly to China, Norway, Japan, and India, and an estimated 1.1 Mt beneficiated locally to produce manganese ferroalloys. In southern Africa the producers of manganese ferroalloys are Metalloys and Assmang, and of silicomanganese Transalloys, Mogale Alloys, and Match Corporation. Submerged arc furnace technology is utilized in the production of high-carbon ferromanganese (HCFeMn) and silicoman-ganese, applying the discard slag practice in both instances. The carbon content of HCFeMn is reduced using converter technology and that of SiMn using the Perrin process. Ninety per cent of the world's manganese ferroalloys production is consumed by the steel industry. The consumption (and production) of manganese ferroalloys therefore closely follows worldwide steel production. From 2001 to 2010, the doubling of the worldwide production of manganese ferroalloys can be attributed to an increase in production capacity in Asia and Oceania, with the largest increase in the production of SiMn. Manganese ferroalloys produced in Asia and Oceania are mainly for the local market, with North America, Europe, Russia, and Turkey the major markets for alloys from southern Africa. The major challenges faced by the southern African manganese ferroalloy producers are increasing electricity tariffs and productivity of labour, which require a concerted effort by all parties involved to achieve a satisfactory solution.
Palavras-chave : manganese ferroalloys; ferromanganese; silicomanganese; southern Africa; South Africa; manganese ore; high-carbon ferromanganese; refined ferromanganese; refined silicomanganese.