Abstract
Sulphide mineral ores are effectively processed across Canada using reagents including xanthates, copper sulphate, and cyanide that have potential to cause acute and long-term environmental hazards. This research project is studying new reagents in traditional froth flotation as an attempt to transition these accepted processing methods to incorporating innovative reagents that will reduce the threat to the environment while maintaining acceptable metal recoveries. Bioreagents produced from naturally occurring, non-pathogenic bacteria found at active and abandoned mine sites are being tested with the objective to apply them into the processes within existing mine infrastructure. Initially, the research characterized an actual sulphidic polymetallic ore that contains base metals (copper, zinc) and precious metals (gold, silver). Experimental considerations to efficiently design a froth flotation circuit using traditional methods were related to the effect of particle size, pH, air flow, bioreagents, and reagent dosage on the grade and recovery of the valuable minerals. Once a standard procedure was developed, the study is now based on experimentation to reduce and/or substitute the hazardous chemicals of froth flotation with viable bioreagents such as pyrite (pyrrhotite) suppressants and silica suppressants. The feasibility of cultivating and enhancing specific strains to suppress gangue minerals and at a minimum maintain recovery rates of valuable minerals from complex sulphide ores will be determined.