One of the most serious problems facing the mining industry is the oxidation of sulphide rich mine tailings and sulphide rich ore bodies that ultimately results in the release of metal-rich acidic waters. ENPAR Technologies Inc. has developed a patented electrochemical technology to prevent the formation of acid mine/acid rock drainage (AMD/ARD). This new approach complements conventional reclamation strategies. Sulphide minerals exhibit semiconductor properties and consequently are amenable to

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... electrochemical manipulation. Electronegative polarization can be used to prevent the oxidation of sulphide rich tailings deposits in a manner similar to that used in cathodic protection of steel structures. The resulting cathodic polarization leads to in-situ electrochemical reduction of oxygen at the tailings/soil interface and a shift of the redox potential of the sulphide minerals to a stability field where oxidation is notthermodynamically favoured. Field testing of the technology has been completed at a 4 hectare tailings site near Sudbury, Ontario (Canada). Electrochemical treatment successfully removed oxygen from infiltrating water, increased the stability of the tailings (lower redox potential), and polarized the tailings. A modification of the design for high sulphide tailings has been developed for sulphide containing waste rock and low sulphide tailings.