Beneficiation of Fine Coal

Aircraft and ground based measurements at Kleinkopje Colliery showed spontaneous combustion to be a significant source of fine particles, with PM2.5 concentrations 91 per cent higher inside a combustion plume than outside it. Sulphur dioxide, nitrogen dioxide and carbon dioxide were also raised in plume, and benzene and toluene were detected. Average particle size was below one micron.

Ion exchange applied to brine from a three stage reverse osmosis plant at eMalahleni converted the brine entirely into saleable fertiliser and explosives feedstock, and recovered close to half of the water the reverse osmosis stage leaves behind. On this basis the existing brine pond and the two planned for the plant expansion would not be needed.

Electrical and electromagnetic ground surveys were run over a Waterberg profile with borehole logs and three dimensional seismic data as control, to test whether cheaper methods can match seismic reflection for locating coal and faults. Resistivity tomography at two electrode spacings, frequency and time domain electromagnetics, controlled source audio magnetotellurics and magnetics were all acquired. Results are preliminary.