Atmospheric Plasma Technologies Towards Elimination of Cyanides from Gold Extraction Processes

Lead Proponent

Laval University

Project Objectives

This project will develop a pilot-scale atmospheric plasma reactor to recover gold (Au) from thiosulfate (TS)-based leach solutions derived from extracted gold ores, as well as a pre-concentration step for TS-based leach solutions produced from gold ore.  The process will use of resins, eluents and reverse osmosis, and improve concentration that will be amenable to plasma treatment.

The project will evaluate the economic performance of this new technology approach (TS-based leaching coupled to atmospheric plasma recovery), by comparing it to the current cyanide (CN) leaching process.

Expected Results

This research project will develop a new generation of clean technologies that have the capacity to eliminate the need for cyanide in gold extraction processes. The plasma process for the extraction of gold from thiosulfate-based leach solutions could decrease by 7 – 10 % the GHG emissions for this industry.  The reduction in GHG emission corresponds to 58 – 83 ktons of CO₂ per year. As an outcome of this project, the new plasma-based systems developed for pilot plant environments, will be evaluated in the perspective of their installation in gold extraction industries. The new plasma technologies would generate jobs for tens of skilled operators, technicians and engineers (manufacturing process, installation in the industries, operation in the gold refineries).  The plasma process will generate gold nanoparticles, a high-technology material that could find a market in electrochemical and catalytical industries.