The mining industry is a large consumer of water, and leachate from tailings dam can contain undesirable levels of heavy metals as well as anions such as sulphate and nitrate. The global consumption of fresh water is predicted to exceed the supply by 2040. Different technologies are used for treating mining wastewater. In the SEESIMA project the use of membranes for cleaning mining wastewater was reviewed, with an emphasis on practical implementations.

The use of reverse osmosis membranes to treat mining wastewater was described as early as 1970, but problems were identified with the low capacity, high pressure drop and operating costs. Further developments have occurred within membrane technologies with the introduction of nanofiltration and adsorptive membranes and membrane distillation. Improved maintenance methods have also been introduced, such as for control of scaling.

In recent years several mine sites have full-scale implementations of membrane cleaning of mine wastewater. Cost estimates are given around as US$1,3/m³, which is at the upper end of costs for precipitation systems, but potentially cost-competitive with ion exchange systems.

A copy of the literature review can be downloaded here.