Rare earth minerals physical separation research - Project leader, Tesfaye Negeri, MMS, NRCan
The purpose of rare earth minerals concentration by flotation and other physical separation techniques is to decrease the amount of nuisance elements in the material to be treated at the extraction stage (hydrometallurgy/pyrometallurgy); otherwise, the consequence will be higher capital and operating costs to produce rare earth oxides and increased environmental concerns regarding process residuals. To date, increasing the concentrate quality/grade has so far resulted in lower recovery of resources.
This project will attempt to achieve both high concentrate and high resource recovery through innovative approaches such as the development and testing of:
- Generic grinding schemes that allow the liberation of individual RE minerals at coarse grind to reduce the generation of hard-to-recover ultrafine mineral particles
- Efficient and cleaner processes consisting of flotation, gravity and magnetic separations
- Ore sorting applications to reduce the consumption of energy, water, and chemicals by rejecting the sterile component or “gangue” (30 - 40% of mine output) of various ore types before grinding
- Collector mixing strategy to maximize RE minerals recovery by size-by-size flotation strategy to increase mineral recovery and concentrate grade
- A mini-pilot plant facility for conceptual flowsheet design