“Although reasonable large coal reserves exist in the portfolios of the traditional coal producers, much of which have been earmarked for replacement of the present mines, these blocks cannot provide the current output of the megamines, with a yearly production of more than 10- million t each,” reports chief mineral economist of the Department of Minerals and Energy’s Minerals Bureau Xavier Prevost. When existing collieries are finally depleted, the local and export markets will be seriously affected, as coal quality and pro-duction will decrease sharply.
“Many have said that, when the coal industry reaches that final stage, the solution will be to develop the backstop Waterberg coalfield; however, there are problems involved with such a plan. In essence, the lack of infrastructure, depth of mining in certain sectors, distance from industrial centres and export harbours and poorer grades of coal throughout that coalfield all suggest that, in 20 years, coal mined in the Waterberg will be too costly to generate cheap electricity, to be able to compete with natural gas in the local market and to produce exports at competitive pri-ces,” explains Prevost.
He is of the view that total extraction and increased use of coal reserves left in the Witbank and Highveld coalfields of the central coal basin would appear to offer the only reasonable answer if the life of the South African coal industry is to be extended realistically and profitably.
Dr Chris Cooper, director of University of Johannesburg’s Institute for Energy Studies, says that South Africa should urgently undertake a review of its coal reserves.
Head of geology of Anglo Coal David Dingemans says “coal reserves are those selected components of the coal seams that can be economically exploited. There has been significant confusion in the past in respect of the conversion of coal resources to coal reserves, which has led to people significantly overstating the amount of future economically exploitable coal.” The key aspect of the definition of a coal resource, Dingemans says, is to ensure that it is intrinsically economic within a timeframe of 50 years, which can be a difficult judgement call.
It is hoped that the new SANS 10320 standard (evaluation of coal resources and reserves) released by the South African Bureau of Standards recently, will assist in defining realistic coal resources from which economic coal reserves will be mined in the future.
The standard details the assessment of coal resources and coal reserves with regard to levels of reliability and confidence, and specifically relates to: n The coal deposit type.
n Evaluation method and pro- cedures.
n Economic assessment.
n Exploration strategy from the target-generation phase to the operational phase.
n The definitions of coal resour-ces and coal reserves.
n Public reporting for securities-exchange purposes.
n Reporting for the national coal inventory.
“The people who need to use this standard include mineral- resource managers, colliery geologists, exploration geologists and anyone considering investing in coal deposits,” Dingemans concludes.