Abstract: Acidity in water leaching from a mass of sulphide tailings is prevented by de-oxygenating the water prior to entering the mass. A cover comprising an electrolytic cell, either galvanic or impressed-current, gives rise to a cathode reaction in which the redox voltage of the water drops to 003 volts or less. The cover can be thinner, and much less expensive, than an equally-effective non-reactive cover. The electrolyte is water contained in water-retaining soil, or a depth of water, lying over the cathode. The cathode is steel mesh, or a layer of graphite, spread over the whole mass of tailings.

Abstract: Acidity in water leaching from a mass of sulphide tailings is prevented by de-oxygenating the water prior to entering the mass. A cover comprising an electrolytic cell, either galvanic or impressed-current, gives rise to a cathode reaction in which the redox voltage of the water drops to 003 volts or less. The cover can be thinner, and much less expensive, than an equally-effective non-reactive cover. The electrolyte is water contained in water-retaining soil, or a depth of water, lying over the cathode. The cathode is steel mesh, or a layer of graphite, spread over the whole mass of tailings.