Unconventional Extraction Methods to Harness the Energy and Carbon in Coal

A digital wetland map and linked database were compiled for the Upper Olifants River Catchment from existing literature, existing wetland layers and aerial photography. Wetlands cover about 2 147 km2, some 14 per cent of the 15 158 km2 catchment. The wetland layer is about 70 per cent accurate and its attributes about 60 per cent, so it suits baseline screening rather than site assessment.

Compared against concrete and gabions on cost, construction time, footprint, durability and safety, the Dongalock product proved cheaper and quicker to install in small and medium incised valley bottom wetlands, and needs no heavy plant, so local enterprises can build it. Concrete still suits large wetlands carrying high water velocities.

The separator handled fine coal and produced a 28 MJ/kg product, but its measured separation efficiency was lower than that of conventional dense medium cyclones and it was harder to operate. Two efficiency tests produced no evidence that the unit outperforms cyclones on fine coal, so cyclones were recommended when the plant was rebuilt at its next site.