La Mine Doyon mill expansion

CIM Bulletin, Vol. 81, No. 909, 1988

G.H. HOPE, Lac Minerals Ltd., Kirkland Lake, Ontario and A.R. MAYCOCK, Wright Engineers Ltd., Toronto, Ontario

La Mine Doyon is a gold mining operation located in northwestern Quebec, approximately 35 km east of Rouyn-Noranda and 85 km west of Val d'Or. The mine is jointly owned by Lac Minerals Ltd. and Cambior Inc. with Lac Minerals as the manager. Production statistics as of February 1987 are 6.4 million tonnes milled at an average grade of 5.8 g/t Au. Current reserves of 9.9 million tonnes at 5.7 g/t Au to a depth of 400 m have been outlined. Indicated reserves below this horizon could considerably increase this reserve. The mine currently consists of two open pit and two underground mine operations, producing approximately 3600 tonnes per day of ore at an average grade of 6 g/t. The ore is currently processed at the La Mine Doyon mill at a rate of 1400 t/d and at Lac's East Malartic mill at 1950 t/d. Ore is also processed intermittently at Lac's Les Terrains Auriferes mill and at Noranda's Home Division. La Mine Doyon is currently in the midst of a program to expand and upgrade the mill at La Mine Doyon. The expansion to 3000 t/day includes the conversion of the existing crushing and grinding circuits to a SAG (semi-autogenous grinding) mill circuit and the existing filter wash plant to a CIP (carbon-in-pulp) recovery plant. The economics of this project are based on reduced operating costs (milling and trucking) and improved recovery due to updated technology.

Keywords: Metallurgy, La Mine Doyon, Gold mining, Milling, Recovery, Ore reserves, Crushing, Grinding, Semi-autogenous grinding.