COLORADO — An environmental services subsidiary of Vancouver-headquartered Alexco Resource Corp. has been awarded a contract for mine/water solids transfer and treatment at the former Platoro underground gold mine.
Alexco technology has been utilized to pre-treat water in the underground sump at Platoro since September 2000, and the treatment results have been very impressive, according to Alexco. Treatment has resulted in overall reduction of dissolved concentrations of arsenic and zinc of more than 90%. The treatment takes about two days’ work to implement each year. The reduction of heavy metal concentrations has enabled significant reduction in the volume of treatment residue subsequently generated in the lime-based water treatment plant, which is operated to provide hydraulic control on the mine pool water levels.
Based on the success of Alexco’s technology in the sump, the latest contract was awarded to treat and transfer the mine water treatment residues that have been generated from the water treatment plant since 1985, when water treatment operations began, and to place these solids back into the underground mine workings. The slurry re-injection of the water treatment solids back into the mine will be beneficial to the continued pre-treatment of the pool, significantly reducing the required land footprint of the solid storage ponds, and is expected to reduce the overall closure liability. Another benefit to the local community will be the beneficial re-use of a byproduct of the potato processing industry as a part of Alexco’s treatment process.
Alexco’s technology converts the chemical form of the solids from metal hydroxides to metal sulphides, after treatment and placement into the sump. Metal sulphide formation when managed appropriately can result in soluble metal concentrations which are orders-of-magnitude lower than metal hydroxides over a wide range of pH conditions.
Learn more about Alexco’s environmental services at www.AlexcoResources.com/s/Services.asp.