High-pH leaching of high MgO sulfide ores
R&D Initiative Summary
Low grade nickel sulfide ores often contain magnesium bearing minerals that report to the concentrates making them difficult to smelt. High MgO concentrates can also be difficult to treat hydrometallurgically as the MgO minerals can consume large amounts of acid and release large amounts of magnesium into the process solutions that ultimately must be removed.
A method of dealing with the high MgO levels, that prevent certain concentrates being smelted or be treated by acid hydrometallurgy, is to treat the concentrator in an alkaline environment. The Sherritt-Gordon process is an example of this approach where ammonia is used to keep the nickel in solution.
The approach we proposed here is to seek alternative chemical systems that will allow leaching and purification of high MgO nickel concentrates in alkali solutions.
High MgO concentrates will become more prevalent as ore grades diminish. A new alkaline process could offer them a home.
This R&D initiative is conducted in parallel with other initiative that are already underway. There is a great potential of discovery that can be extrapolated to a multitude of chemical mining processes. St-Georges team has not established a strict timeline for any deliverable.
Early state small scale laboratory testing is to be initiated to evaluate possible chemical systems. With laboratory success, larger scale development programs will follow.
On going operation with Strategic Metallurgy our Joint-Venture partner. This initiative does not have a fix budget and has a low priority at this point in time.