Recovery of gold from old tailing ponds

CIM Bulletin, Vol. 79, No. 895, 1986

M.A. CRISTOVICI Research Scientist, CANMET Ottawa, Ontario

In the last few years CANMET has taken the initiative by investigating the possibility of reactivating abandoned old tailings dumps (for gold production) which would be of potential economic interest across Canada. Nova Scotia was one location where numerous gold processing plants were in operation in the early days. A survey of the old tailing dumps was conducted and some areas of interest were selected. Among them were the sites identified as Lake Charlotte and Forest Hill. Ore samples collected from those tailing ponds were examined for their chemico-mineralogical composition and investigated for gold extraction. Three technological concepts were tested: flotation, direct cyanidation and flotation followed by cyanidation of the flotation concentrate. The combined flota-tion-cyanidation variant, yielding a gold recovery in the range of 90%, was recommended for processing the tailing ore. Pilot-plant runs carried out by a commercial testing firm (data not included in this paper) confirmed the conditions and results of CANMET's technology. As a result a consulting-engineering firm designed the processing plant which is expected to begin operation in the near future.
Mots Clés: Mineral processing, Tailing dumps, Gold recovery, Flotation, Cyanidation, Milling.