Over 20 tests on several samples have been completed to date to investigate the impact of bake conditions including acid addition, concentrate grade and bake temperature.
The previous hydrometallurgical flowsheet that was included in the Wicheeda preliminary economic assessment (PEA) was based on a more costly and complex gangue leach-caustic crack process. Upon joining the team, Defense Metals’ lead metallurgical consultant, John Goode, recommended investigation of the acid-bake process for the Wicheeda ore.
The initial test shows that adoption of the sulphuric acid-bake approach can result in improved REE extraction. Across all tests, including those under sub-optimal conditions, the neodymium-praseodymium extraction is 94%, with better test results showing 97% to 99% extraction.
The testing program will be concluded in the last quarter of 2022, providing data to allow a detailed design as well as capital and operating cost…
