By Gary Thomas
Greenland Minerals and Energy has updated the ongoing process development for the Kvanefjeld multi-element project (Kvanefjeld).
REP = Rare Earth Phosphate mineral concentrate (dominantly steenstrupine and closely related minerals). REP contains 12% TREO and 0.2% U3O8
To process Kvanefjeld ore, Greenland Minerals and Energy has chosen a flow-sheet subsequent to an extensive flow-sheet selection study carried out during 2011. This flow-sheet, including concentration through froth flotation followed by atmospheric leaching, laid the foundation for the company's Prefeasibility Study about Kvanefjeld. The Prefeasibility Study identified that Kvanefjeld is a long-life, cost-competitive producer of zinc, uranium oxide and light and heavy rare earth elements.
Notably, the process flow-sheet has been designed along with a methodical and extensive test work program. The flow-sheet's metallurgical development is upgraded and process design work is partly completed.
Highlights of the Metallurgical Test Work Program are as follows:
- More than 250 tests regarding the concentrator (beneficiation) circuit have been completed
- Concentrator circuit's feasibility process design is nearing completion
- More than 50 tests regarding the refinery circuit have been completed
- Refinery well's feasibility process design is well developed
Since Greenland Minerals and Energy's test work programs are efficient in de-risking process design for the concentrator and the refinery, the company is now planning to start pilot plant operation as its next move in process development.
The capability to produce a high grade mineral concentrate by beneficiating ore and the capability to recover rare earths in large quantities from the concentrate without the need for complex and high-cost metallurgical processes are the two most significant metallurgical aspects required for a rare earth project to be commercially successful.
The Kvanefjeld flow-sheet possess both attributes as it beneficiates ore with an unprecedented upgrade ratio and purifies the mineral concentrate with the help of a simple atmospheric acid leach process. It generates high metal extractions without using complex and expensive high-temperature mineral cracking processes.
The concentrator circuit comprises froth flotation subsequent to comminution and generates a mineral concentrate comprising roughly 0.2% U3O8 and 12% total rare earth oxide. The next step of Greenland Minerals and Energy's concentrator test-work program is a campaign for a second pilot plant. This campaign, slated for November 2012, will produce roughly 300 kg of rare earth-rich mineral concentrate by processing 4 tons of ore.
Greenland Minerals and Energy has evaluated economically feasible hydrometallurgical process to refine Kvanefjeld concentrates. The company's next step in refinery test-work program will feature mini-pilot plant campaigns at Australian Nuclear Science and Technology Organization in Sydney. These campaigns, scheduled for 2013, will use concentrate manufactured from the flotation pilot plant campaign slated for November 2012.