Tests of simple acid extraction solutions on coal ash samples in China have shown that 70-80% of the uranium contained in the fly ash from the Lincang germanium area is recoverable, Sparton Resources (SRI-V, SPNRF-O) says.
Sulphuric and nitric acid leach tests on coal ash from Lincang, in China’s southern Yunnan province, yielded uranium content of 281 ppm (0.028%) uranium oxide, or about 0.73 lbs. uranium oxide per tonne.
A two-hour leach test using 5% sulphuric acid ended up with recoveries of 70% of uranium into solution. Using 10% nitric acid, test recoveries totalled 80% of uranium.
The Toronto-based company signed an agreement in January 2007 with the Xiaolongtang Guodian Power Co. of Yunnan for a three-phase program to test and possibly commercialize the extraction of uranium from waste coal ash at the company’s three thermal power stations.
The Xiaolongtang, Dalongtang and Kaiyuan stations are within 20 km of each other and burn coal from a centrally located open pit-lignite coal mine containing anomalously high uranium content. The plants are about 250 km southeast of the provincial capital of Kunming.
The waste deposits are estimated to contain more than 450,000 tonnes of ash material.
Additional work is being carried out to raise the efficiency of the leaching with different acid strengths and column tests of agglomerated ash to simulate heap-leach conditions.
Longer-term testing work will involve larger samples and samples taken from other parts of the various waste piles in the Lincang area.
Advanced bulk sampling and uranium oxide recovery programs are expected to be complete by the end of the year.
Sparton says low sulphuric acid consumption in the process (about 250 kg per tonne at 5%) is positive and consistent with the material’s low lime content of about 3%.
A local Yunnan laboratory conducted the test work and duplicate samples currently are being tested by Lyntek of Denver, Colo., Sparton’s process engineering consultants.
The most recent results are consistent with data on recoveries when uranium was produced from waste ash in the Lincang area in the 1970s by the Production Bureau of the China National Nuclear Corp.
Both provincial and local area governments are keen to start an environmental cleanup of radioactive waste material.
The ash content is 20-30% and due to its high radioactivity levels, is not suitable for most cement use.
The Xiaolontang station alone produces 600,000 to 900,000 tonnes of fly and bottom ash annually and has stockpiles of about 5 million tonnes of recoverable ash.
Fly ash makes up about 90% of the total ash production from these stations.
Since signing the agreement in China, Sparton has gone on to sign similar agreements in six Central European countries and South Africa.
The junior explorer is currently trading at about 21.5 a share and has a 52-week trading range of 16- 60. It has 63 million shares outstanding.
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