The head grade prior to test work assayed 232ppm U3O8 with a final product grade in 30% of the ore of 871ppm U3O8, representing an increase of 375%.
Through its consultants, SRK Consulting, West Australian Metal commissioned a program of scoping metallurgical assessment at the Australian Nuclear Science and Technology Organisation (ANSTO).
About 1.2 tonnes of ore representing the calcrete and weathered bedrock ores were shipped to ANSTO in September 2009. The ore mineral in both is predominantly carnotite, although other uranium phases are also present in the weathered bedrock.
Screening, scrubbing and ore sorting tests carried out on two 500kg samples have confirmed that the ore is amenable to upgrading.
In calcrete dominated ore, testwork has shown that around 90% of the uranium can be retained in 37% of the ore, with an increase in grade of 242%.
Initial diagnostic leach tests using 0.4M Na2CO3 with 0.1 M NaHCO3 at 90oC for 24 hours achieved a uranium extraction of 96% from both the weathered bedrock and calcrete. Bottle roll tests are currently in progress.
West Australian Metal’s Chief Executive Officer, John Young, said: “These are very encouraging results which will form part of the current SRK Scoping Study due for completion by second quarter of next year.“
“The results confirm the upgradeability of Marenica ore and have exceeded our expectations in terms of the grade uplift and extractions achieved from preliminary diagnostic leach tests,” Young said.
“While the results are preliminary and more work is required, we are very encouraged by what we have seen to date and this gives us confidence to press ahead with our Scoping and Feasibility Studies,” Young added.
The encouraging testwork results follow a positive interim resource upgrade announced for the Marenica Project last week. A full resource upgrade is scheduled for the early part of 2010 as the foundation to advance the Project towards production.
