The mining industry often collaborates with other industries, particularly the sciences, which play a critical role in research and development and improve various areas of the industry. Inside Mining speaks to two female scientists who developed a system that purifies water contaminated by acid mine drainage.Mariekie Gericke is a manager at Mintek’s Biotechnology Division while Kerri du Preez is a senior scientist in the same division. Mintek, a state-owned science council, develops technologies for the mining and metallurgical industries. The intent of the cloSURE technology is not to produce potable water, but rather to provide water that is fit for use for irrigation, to provide opportunities to local communities after mine closure. The integrated nature of the plant is especially distinctive in that it aims to treat waste effluent on a sustainable, long-term basis so that it may be reused in the production of agricultural crops. “We developed a low-tech, low-maintenance, low-cost process for the treatment of acid mine drainage, mainly for applications after mine closures,” explains Gericke.
The technology is based on biological sulfate reduction, which involves the conversion of sulfate to sulfide under anaerobic conditions by sulfate-reducing bacteria, while simultaneously producing alkalinity in the form of bicarbonate. In addition, the sulfide produced in the process binds to dissolved metals, facilitating their removal by precipitating as metal sulfides that are retained in the reactors or ponds. “Our process is a biological process. We use microorganisms to do all of the work,” Du Preez says.This article was first published in Inside Mining’s Women in Mining Special Interest Publication (SIP).