Wastewater treatment at Hudson Bay Mining and Smelting Co., Limited

CIM Bulletin, Vol. 73, No. 818, 1980

R.V. TYPLISKI Group Leader, Environmental Control, G.J. LABARRE, Technical Foreman, Flin Flon Mill, Hudson Bay Mining and Smelting Co., Limited, Flin Flon, Manitoba

Hudson Bay Mining and Smelting Co., Limited, Flin Flon, Manitoba, has developed a metallurgical wastewater treatment system employing two-stage lime neutralization, sludge recirculation and conventional mechanical thickening.Laboratory investigations, initiated in 1970, led to the construction of a pilot-scale mine-water treatment plant, at Schist Lake Mine, in early 1971. This plant, treating 600 cubic metres /day of wastewater containing 30-60 mg/l zinc, demonstrated metal extraction efficiencies of 99% under normal operating conditions.On the basis of this pilot work, a second pilot-scale treatment system was established in 1975 at the Flin Flon metallurgical plant to treat zinc refinery process waste water. Through numerous improvements, including automatic control equipment, the system has evolved to a full-scale operation capable of treating 800 cubic metres/day of wastewater containing 4-11 gm/l zinc. Treated effluent contains 0.2-20 mg/l zinc. The hydroxide sludge produced returns to the metallurgical process for the recovery of metals while clarified effluent discharges to waste.With the system, Hudson Bay Mining has achieved its original goal: the reduction of environmental contamination, while realizing a return from metal recovery.

Keywords: Wastewater treatment, Hudson Bay Mining, Flin Flon, Neutralization, Sludge recirculation, Thickening, Schist Lake Mine, Automatic operation, Water treatment.