The Equity leach plant

CIM Bulletin, Vol. 78, No. 884, 1985

C.R. EDWARDS, Leach Plant Superintendent, Equity Silver Mines Limited, Houston, B.C.

Equity Silver Mines Limited, Canada's largest silver mine, has designed, built and operated a leach plant to reduce the levels of antimony and arsenic in its silver-gold-copper flotation concentrate. The orebody contained deleterious antimony and arsenic minerals in such proportions that the economic long-term sales contracts necessary to obtain project financing could not be procured. Construction of the leach plant therefore allowed development of the mine to proceed. Although the plant took some time to reach design throughput and product specifications, due to the complex and unique nature of the operation, these goals were successfully met and surpassed. This paper describes the physical plant and/or process technology modifications made to mold the main processes—concentrate leaching and filtering, autoclaving and filtration of by-products, and crystallization of salt cake—into an effective, economic operation.

Keywords: Process development, Filtering, Leaching, Plant design, Process technology, Antimony, Arsenic, Silver.