Alligator Energy Ltd (ASX:AGE) has achieved high diagnostic uranium extraction results of up to 98.6% in all tests, demonstrating a high level of leachable uranium is present in feedstock from the company’s Samphire Uranium Project in South Australia.
Alligator engaged with the Australian Nuclear Science and Technology Organisation (ANSTO) to complete test work covering the leaching of uranium through diagnostic, bottle roll and column leach tests, and ion exchange (IX) uranium extraction using the latest Strong Base Ion salt tolerant resins.
“Highly successful” extraction test work
“The ANSTO test work outcomes have been highly successful from Alligator’s perspective, confirming anticipated results,” Alligator Energy CEO Greg Hall said.
“The high level of uranium extraction during the various leaching tests using existing groundwater conditions have shown that nearly all the uranium present is leachable.
“In particular, the column leach tests over 33 days emulate the potential ISR in-ground conditions and indicate an excellent result of leaching characteristics and potential performance.
“The loading results of uranium onto salt tolerant resins within the saline ground water was also anticipated, and even during our early December 2020 desktop study we had assumed a certain level of ground water pre-conditioning would be needed.
“Our primary consultants WGA are currently uploading these results into our scoping study, with work on this over the coming weeks. We now anticipate announcing these results during January 2023.”
Test work results in detail
As stated above, Alligator and ANSTO undertook a multi-phase extraction test work program, testing ground water suitability, uranium extraction levels, and simulating in-situ recovery (ISR).
Bottle roll tests – a step of the extraction process that produces leach liquor for subsequent column leach test work – confirmed high uranium extraction potential, with results of between 86.1% and 93.3% with low reagent consumption.
The in-situ recovery (ISR) process was then simulated in two horizontal column leaching tests for over 33 days, using Samphire groundwater from the mineralised zone adjusted to a pH of 1.5.
High uranium extraction levels were once again confirmed, with results between 92.9% and 96.3%.
As an added plus, acid consumption was low in the long duration test, with relatively low iron addition required in the leaching process.
The IX test work indicated (as expected) that uranium resin loading occurred in all scenarios, with loading efficiency negatively impacted by higher ground water salinity.
Alligator proposes to use reverse osmosis to treat the groundwater on-site prior to ISR mining.