Just a week after announcing a maiden inferred resource, sulphate of potash (SOP) hopeful Trigg Mining (ASX: TMG) has launched a test pumping program, along with trenching, as it works to bump that resource into the indicated category.
With 5,720m of drilling completed, the only additional information needed to lift Lake Throssell project the indicated category is test pumping and additional aquifer property data.
The project is located 170km east of Laverton on the Great Central Road connecting Laverton to Alice Springs.
The transition from inferred to indicated will form the basis of a scoping study and help estimate flow rates for potential SOP production.
The maiden resource for the project totals 14.2 million tonnes of drainable SOP at 4,638 milligrams per litre of potassium (or 10.34 kilograms per cubic metre of SOP).
Estimating the aquifer properties
Last week, Trigg also revealed an updated exploration target range of 2.6-9.4Mt at 9.5-10.3kg/m3 (grams per cubic metre) of potassium sulphate.
The trenching works will allow Trigg to estimate the aquifer properties of the lake surface aquifer.
Trenching and test pumping is designed to enable estimates of drainable porosity and permeability of the surficial aquifer to be calculation.
“Pumping from the trial pits and trial trenches will create draw-down of the water table in the surrounding sediments which can measured by the monitory pits, with the rate and magnitude of the draw-down used to estimate drainable porosity and permeability of these sediments,” Trigg stated.
The company added that this latest program follows on from the “highly successful” drilling campaigns at its flagship project.
Indicated resource makes for higher confidence
Drilling has established the presence of a high-grade brine deposit within the lake surface and the entire palaeovalley sequence.
Trigg managing director Keren Paterson said this latest program will help establish the economic parameters to underpin the planned scoping study.
“Having a higher-confidence indicate resource will be an important de-risking step for the project,” she added.
“This represents another really important step forward towards creating a major new sulphate of potash production hub at Lake Throssell.”
Lake Throssell is one of several projects aimed at reducing Australia’s dependence on import of potash (both muriate of potash and SOP) now running at about 250,000t per annum.