18 October 2013 – South Africa’s Limpopo coal deposits in its north host the vast majority of the country’s remaining largely undeveloped, coal resources. Coal analysts describe the Waterberg coalfield as South Africa’s largest resource which could soon become the country’s main source of coal.
Four coal basins have been have been identified as the major coal deposits in Limpopo. These are located in the Waterberg region near Lephalale; between the Soutpansberg Mountains; the southern banks of the Limpopo River and the Springbok Flats between BelaBela and Zebedeila and are calculated to hold more than 40% of South Africa’s in-situ mineable coal reserves.
In the Mopane area between the Sand River and the Blouberg mountains, exploration over the last two years indicates the potential for extracting coal-bed methane (CBM) gas, as an energy source for domestic, industrial and energy generation applications.
The coal seams at Mopane are similar in quality and formation to those that have been successfully developed in the nearby Waterberg Basin where a trillion cubic feet of CBM has been calculated. Unlike traditional mining operations, the coal is not removed or extracted, as CBM requires that the coal be left in place and only the natural gas extracted.
The Limpopo Province’s coalfields could also provide another source of natural gas through underground coal gasification (UCG) which takes place in undisturbed coal seams. The process entails the gasification of coal in-situ by drilling two or more boreholes into a coal seam. The coal is ignited and the resulting gasification is maintained by injecting air through one of the boreholes. The resulting synthetic gas (syngas) is used for power generation or the manufacturing of key liquid fuels such as diesel fuel or methanol.
The challenges of water availability and the distance from the South African industrial hub are among those faced by anyone wishing to develop the potential of these coal deposits. The expected large-scale mining expansion in arid Limpopo will require the province to find an additional 80 million cubic metres of water a year to sustain itself. In the Lephalale area, Eskom’s power stations and local farmers rely on the Mokolo dam near the mining town of Lephalale for the supply of water.
The protection of this area plus the scarcity of water has motivated the need to design new coal handling and processing plants as zero effluent facilities have become an environmental requirement.