Acid mine drainage (AMD) continues to be both a curse and an opportunity. Water is precious and no matter what form it takes, studying economical ways of recovering it is appropriate. In this edition, Mining Weekly reports on three activities within the State-owned Council for Geoscience (CGS) that dip a toe into improving insight into AMD, gold mine tailings and tailings handling know-how. Tailings is muck and there is usually money in muck, as they say. But finding ways to extract that money without investing more money in it than you stand to get out of it, is the hard part. Tailings occupy valuable land and it should also be borne in mind that it needs to be removed to unlock the value of the land beneath the tailings for alternative development. The CGS researchers should be highlighting how the private sector can come in to commercialise recovery opportunities. They should be whetting the appetite of business, otherwise the tailings issue could end up as an expensive cost centre for already hard-pressed South African taxpayers.

Mining Weekly publishes a CGS hypothesis on page 14 of this edition that has the potential to take a grip on AMD and at the same time use gold mine tailings as sources of aluminosilicate for the synthesis of mineral-binding geopolymers used in cement manufacturing. As CGS intern Leahn Pieterse points out, Australian roads authority VicRoads has apparently recognised geopolymer concretes as being an equivalent of ordinary Portland cement for nonstructural applications. An important point is that high-performance geopolymer concretes have already been commercialised and that there are several demonstration plants in the world from which to learn.

Also on page 14 of this edition, Mining Weekly reports on the need to better understand mine water sources and contaminants at decanting points. In this report, CGS environmental geoscientist Thato Kgari outlines how AMD is continuing to degrade surface and groundwater qualities in some areas of South Africa. Kgari notes that limited studies have been done in South Africa into the feasibility of using hydrological tracer techniques to determine mine water sources. In this, lessons could be learnt from Germany, where regulations govern the use of tracers such as dye, salt and stable isotopes – substances that can be carried in solution to assist with mine water management, treatment and remediation.

On page 15 of this edition, Mining Weekly reports on a review of mine residue disposal facilities (MRDFs) literature and an evaluation of information from local historical cases of tailings dam failures. The general conclusions reached by this preliminary analysis indicate that, while all the investigated MRDFs are geotechnically stable, an urgent need exists for a comprehensive decision-support system to enforce regulations regarding monitoring, life-cycle operation, management and decommissioning processes for tailings facilities. CGS senior scientist and engineering geologist Sifiso Ngubelanga points out that unusual rainfall or heavy storms are the most common causes of tailings dam failure. Only six of 27 active, inactive and abandoned tailings dams identified during site visits had slurry deposition; the rest were inactive, abandoned or were being remined.