Trigg Mining (ASX: TMG) has announced the completion of a sighter evaporation trial on brine samples from its flagship Lake Throssell sulphate of potash (SOP) project in the Laverton region of Western Australia.
The trial was conducted at a laboratory in metropolitan Perth on a 29-litre sample sourced from a combination of trench and bore brine at the project.
It was carried out over 92 days with continuous gentle agitation of the samples to simulate operational conditions of brine flow through ponds affected by wind, waves and sunlight.
Bulk evaporation program
The logged data will be used to establish guideline conditions for a proposed bulk evaporation program, which is planned to commence later this month.
The program is aimed at simulating operational steady-state brine evaporation and will generate salt products for trialling optional SOP processing routes.
Individual species salts and KTMS (or potassium-rich mixed salts) will be tested to generate operational and engineering design data for the Lake Throssell pre-feasibility study (PFS).
The blended KTMS will also be processed to produce an export quality SOP product for inspection and analysis by potential offtake partners.
Initial results from the sighter evaporation trial have also provided Trigg with baseline data for an early design dynamic mass balance pond model which will be used in the early stages of the PFS engineering to estimate required pond numbers and their layout.
Harvesting brine water
The Lake Throssell SOP project is proposed to comprise the harvesting of brine water from subterranean aquifers, evaporation ponds, a processing plant and supporting infrastructure to produce a naturally-forming, potassium-rich salt which can be used globally as a fertiliser and for other industrial purposes.
Highlights of a scoping study released in October included an annual nameplate production target of 245,000 tonnes per annum SOP over a 21-year life of mine, based on a total drainable mineral resource of 14.4 million tonnes at 4,665 milligrams per litre of potassium (or 10.4 kilograms per cubic metres of SOP).
The study estimated an initial capital cost of $378 million, including a $70 million contingency.
Lake Throssell is forecast to generate average earnings before interest, tax, depreciation and amortisation (EBITDA) of $97 million per annum at an SOP price of US$550 per tonne (A$807/t).