Australian Potash has cranked up the JORC mineral resource of its Lake Wells sulphate of potash, or “SOP”, project near Laverton, WA, by 23% to 18.1 million tonnes of drainable SOP.
It is noteworthy that this resource is solely within the measured category, which gives the company a high degree of confidence that it can support its initial planned 150,000 tonne per annum project for a long, sustained period.
The upgrade is based on extensive hydrogeological data and rigorous modelling, which also returned consistent brine grades averaging 7455 milligrams per litre of SOP.
An ore reserve estimate is now being finalised for the definitive feasibility study.
Managing Director Matt Shackleton said: “Based on data from more than 60,000 metres of drilling, 300,000 metres of seismic surveys and 1,329 exploration holes that has been completed by APC and others at Lake Wells, today’s resource estimate upgrade establishes an extremely solid base for the ore reserve estimate underpinning the definitive feasibility study’s economic analyses.”
“APC utilises a specific yield, or drainable porosity, factor in its resource estimates. Specific yield gives an estimate of the proportion of contained brine that could potentially be recovered from an aquifer. The notion of an arithmetic estimate, or total porosity, based on area of aquifer is anathema to sound hydrogeology.”
“The release of this upgraded resource estimate today marks the commencement of the reporting for the definitive feasibility study findings.”
Lake Wells is located 280km by road from bulk rail terminals near Leonora in the northern WA Goldfields region.
Australian Potash has drilled production wells that confirm the target paleochannel could flow brine above project requirements, whilst its pilot evaporation pond program has verified the accuracy of its evaporation model.
Recent work has also confirmed that the extensive layer of low permeability clay at the lake surface could allow the company to avoid the capital expenditure associated with lining the pre-concentration ponds.
Additionally, pilot processing has proved that a high-grade SOP with a purity of 98% can be produced from the Lake Wells brines.
By Matt Birney
