February 2008

Award received for reduced cyanide consumption

By C. Hersey

From left: Claude Demers, ADRIQ, Claude Gagnon, COREM (research scientist), Gilles Landry, IAMGOLD (Sleeping Giant mill), Yves Harvey, COREM (executive director), Pierre Pelletier, IAMGOLD, Jean Belzile, École de Technologie Supérieure, Alain Coulombe, SolVision | Photo courtesy of ADRIQ

IAMGOLD and COREM jointly received the 2007 ADRIQ (Industrial Research Association of Quebec) award in the Process Innovation category, recognizing their commitment to innovative practices. As a multi-industry organization, ADRIQ accepts nominations from various companies involved in research. The award presentation ceremony was held at Windsor Station in Montreal on November 22, 2007.

The celebrated technology is actually a fresh take on the traditional cyanidation process — a newer version of an old technique. Donald Leroux, director of technology at COREM, said the new process basically consists of handling the coarse particles separately from the fines. In the traditional process, an excess of cyanide is consumed in the side reactions, and since having implemented the new method, cyanide consumption has been reduced considerably — by about 30 per cent.

The results are a huge success for both the company and the environment. “Since only a fraction of the cyanide is used for leaching gold (the bulk of cyanide is consumed by minerals other than gold), a 30 per cent reduction of cyanide consumption makes the amount of cyanide discharged to the environment drop by an even greater percentage. The reduction of cyanide consumption has no negative effect on gold recovery, and in addition to the significant economic benefits, the plant reports a substantial drop of the weak acid dissociable cyanides contained in the plant tailings, a notable environmental performance improvement,” said Leroux.

COREM is owned by a consortium of 10 companies (IAMGOLD being one of them), and the idea for the new process came up in a members’ meeting about three years ago. Since then, the technique has met with great success. The idea itself was developed jointly and Leroux gives full credit to COREM’s members. The companies were brainstorming, seeking out a new proposal to research, and came up with the size-by-size cyanidation process.

During the three years since, about $800,000 has been invested in the project and its implementation. The technology (developed and patented by COREM) was implemented last year by IAMGOLD at their Sleeping Giant mill near Amos, Quebec. This first and successful large-scale application of the technology was made possible by a well-seasoned team of plant metallurgists and research scientists and the strong support of IAMGOLD management. “The process was initially commissioned at the mill as a pilot process for about one month before being permanently implemented,” said Leroux, who highlighted the individuals who really drove the project: Pierre Pelletier, Gilles Landry and Martine Deshaies from IAMGOLD, and Claude Gagnon, Michel Turbide, Ahmed Bouajila and Mohamed Ourriban from COREM.

Of course, as with any new technology, there is always room for improvement. Currently, the size-by-size cyanidation process is being further developed using ore samples from IAMGOLD and other COREM?members who can keep the exclusive rights of this patented technology for a period of up to five years.

With a 30 per cent reduction in cyanide consumption and in the amount of cyanide dumped into the environment, it’s hard to go wrong. For COREM and its members, the results speak for themselves.

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