Removal and recycling of metal contaminants and other by-products from acid mine drainage is the subject of this MEND project. Critical literature surveys and investigations in several selected research alternatives such as chemical treatment (that is modifications to lime neutralization), solvent extraction, ion exchange, bioadsorption and electrowinning, are aimed at the development of a viable treatment process. The technical and economic feasibility of the techniques will be evaluated, in search of a process that produces a high quality effluent, secures a satisfactory revenue and minimizes/eliminates hazardous sludge production.

A literature review was carried out by CANMET scientists from four different disciplines in the field of metals and/or by-products recovery from acidic mineral effluents. Existing expertise from the application of these technologies in related fields in mineral processing, as well as preliminary results from investigations with acidic mineral effluents have been utilized to evaluate selected publications and to determine the most promising process approaches. A preliminary compilation of data in acidic mineral effluents in Canada has been made, with particular interest in high metal concentrations.

Discussion provided in this report supports the opinion that the recovery of metals and/or by-products from acid mine drainage is a promising treatment approach from a technical, economical and environmental point of view. Detailed laboratory investigations should follow to study the recovery of various by-products, to develop a treatment process flowsheet and to evaluate the economical and environmental benefits. Samples from two milling operations should be selected to carry out the tests.