Removal of toxic metals and sulphate from mine water technology comparison ettringite precipitation vs. nano-filtration by pilot trails

A pilot plant for the treatment of acid mine drainage was tested in the Apuseni Mountains on behalf of the Rosia Montana Gold Corporation. A containerised mobile unit was developed and built by a team of WISUTEC, G.E.O.S. and BAUER Water and operated for a period of 7 months. The plant allowed testing of two innovative treatment technologies, a two-stage precipitation process, and nano-filtration including optional solution pre-treatment and concentrate neutralisation, both of which proved their reliability in relation to durability and compliance to the stringent Romanian discharge limits (NTPA 001/2005). Valuable operating and cost data for future process design were obtained.