Low relative density processing of fine coal

Abstract

It is anticipated that much of South Africa’s coal will in the future be mined from the Waterberg and Limpopo coal fields which are situated in the north of the country. The coal from these areas contains some bright coal and can be processed to produce a semi-soft coking coal which constitutes a valuable resource for the country’s iron and steel industry. Production of a semi-soft coking coal requires the coal to be processed at very low relative densities in order to obtain low-ash coking coal products and it is furthermore required to crush the coal to about 20 mm top-size in order to liberate the coking coal. This results in a significant amount of fine coal reporting to the plant which also requires to be processed at low relative densities in order to yield coking coal. Processing of the coal at low relative density is very difficult to achieve, especially on the fine coal (-1+0.1 mm size fraction). This paper illustrates the importance of fine coal processing for the Waterberg and Limpopo coal fields and compares the currently available fine coal processing technologies.