Cyanide effluent control by freeze/thaw processing.

With many northern gold mining operations the disposal of waste water from the process presents some unique problems. The level of heavy metals and cyanide is generally too high to allow discharge to the environment. Total impoundment of the effluent in tailing dams or the use of expensive treatment plants is necessary to ensure protection of the environment. The costs and dangers of these treatment methods cannot always be justified in the remote locations of these mines and alternatives must be explored.In this paper, experiments have been performed to determine the partial freezing and melting characteristics of cyanide solutions as well as the rates of natural degradation. These studies could result in a novel method to protect our northern environments and ensure the continued operation of gold mines in these regions in a safe and economic manner. A multi-pond containment system has been proposed which may be feasible in certain circumstances.