Application of Earth ion Exchange Technology to Convert Acid Mine Drainage From Exxaro’s Matla Mine Into Saleable Products

Co-treating coal discards with sewage sludge by hydrothermal carbonisation gave hydrochars with better physicochemical properties than treating either waste alone. The blended hydrochar reached a surface area of 20.35 m2/g and a pore volume of 0.38 cm3/g, and removed 97.19% of nevirapine and 93.32% of lamivudine from recycled water. Routes to activated carbon and hydrogen storage were also assessed.

Government and industry aeromagnetic data over the Witbank Coalfield were merged into one set of maps and GIS compatible files, and roughly 1200 dyke traces were interpreted from them. Purchase of a 200 m line spacing government survey removed the need for infill flying. One participating company valued advance knowledge of a single underground dyke at about R15 million.

Irrigation with calcium and sulphate rich mine water proved feasible and sustainable over eight years at a Mpumalanga colliery, with no significant impact on soil, surface water or groundwater. Sugarbeans, wheat, maize, potatoes and pastures were grown on a commercial scale. High calcium and magnesium suppressed potassium uptake, and waterlogging from poor site selection was the main problem.