Hydrometallurgical Treatment of Pyrrhotite Concentrates
Pyrrhotite (Po) is the main sulfide gangue associated with mainstream nickel sulfide ores.It typically contains 0.6 to 1.0 % Ni within its matrix, and represents a considerable portion (maybe 10 to 15 %) of nickel in this type of ore.
In the past pyrrhotite was floated into the final concentrate and the contained nickel was recovered to the nickel matte produced by the smelter. Unfortunately, the sulfur from the Po (along with the sulfur associated with the more valuable sulfides) was converted to sulfur dioxide and ejected to the atmosphere.
Sulfur dioxide was the major contributor to the acid rain problem that finally began to be addressed in the 60’s and 70’s.
Most nickel concentrators stopped recovering Pyrrhotite and rejected it to the mine tailings or in dedicated pyrrhotite tailings dams. This significantly reduced the sulfur dioxide produced and with the addition of acid plants, this removed most of the remaining sulfur dioxide emissions.
Long term environmental problem
Pyrrhotite present in wet tailings dams constitute a serious long-term environmental issue related to the eventual emergence of the Acid Drainage phenomenom.
Within the “Acid Drainage R&D Initiative” St-Georges is developing methods to enable the re-treatment of pyrrhotite containing tailings through a process to recover the nickel and other metal present and stabilise or extract the remaining sulfur.
Part of the “Acide Drainage R&D Initiative” financed by St-Georges for 70% and Strategic Metallurgy Pyt Ltd. for 30%.
Strategic Metallurgy has a strong background in hydrometallurgy and has a large knowledge base assigned to this project hence making it possible to go from the proof-of-concept and pilot plant testing stages to commercial deployement ready within 18 months.
- Billion of tonnes of target materials sitting in tailing dams all-around the world, including Canada.
- Pyrrhotite is also being rejected on an ongoing basis from the nickel concentrators operating today and retrofitting technology can be commercially deployed within these legacy mine processing circuits.
- Development of this suite of solution has tremondous positive impacts for the Environment and open the door to the development of a multitude of related applications.
- Pilot Plant testing within Strategic Metallurgy’s Plant in Perth, Australia could become an early cash-flow generator for the Company.
- The development and the on-site testing phase of this project might be admissible to governmental grant.