Trigg eyes potash resource upgrade after positive brine testing

ASX-listed premium fertiliser hopeful Trigg Mining has edged closer to development of its Lake Throssell sulphate of potash project east of Laverton in WA with a “highly successful” brine pumping field trial. The Perth-based company says the brine pump testing was aimed at better understanding the properties of the project’s lake surface aquifer.

Trigg’s Lake Throssell project shares the spotlight on an evolving potential sulphate of potash production hub in the well serviced Eastern Goldfields region with other players including Australian Potash at its advancing Lake Wells project about 180km north-east of Laverton.

Trigg boasts a whopping 3,500 square kilometres of strategic landholdings located near established energy and transport infrastructure.

Australian Potash, Trigg and other aspiring sulphate of potash project developers are endeavouring to position themselves to respond to the anticipated burgeoning demand for premium-quality fertiliser.

Sulphate of potash is an essential fertiliser for high-value, chloride sensitive crops such as fruit, vegetables, avocados, coffee beans, grapes, tree nuts, cocoa and anything cultivated under glass and in arid and acidic soils.

It is required in large quantities for optimum plant growth and crop yields. 

Trigg hopes to deliver a maiden indicated mineral resource in the current quarter for Lake Throssell on the back of its recently released inferred-category resource estimate for the high-grade deposit of 14.2 million tonnes of drainable sulphate of potash at 4,638mg/L potassium.

The company has also put out an exploration target of an additional 2.6Mt to 9.4Mt.

According to Trigg, the brine extraction from the latest trial trenches and test pits work indicated the properties of the upper aquifer support the modelling needed to take the mineral resource to the indicated level.

Management says the indicated resource figures will provide a critical input to Trigg’s scoping study that it recently kicked off.

The just completed brine pumping tests from two trial trenches shored up the extraction potential of the lake surface aquifer, which Trigg says is slated to be the source of initial sulphate of potash production from a trench network.

Lake trenching and test pumping at Lake Throssell involved two 100m-long trenches and seven test pits distributed across the existing inferred resource.

The trial trenches were surrounded on all sides by several monitoring pits. They were pumped until water levels in most of the monitoring pits stabilised.

The test pits, which consisted of a small pumping trench between 6m and 9m long with an adjacent monitoring pit, were then dewatered and the brine level draw-down and recovery rates monitored.

Trigg says the brine levels, flow rate and quality were frequently monitored throughout the testing process.

Trigg Mining Managing Director Keren Paterson said: “This is a another significant and encouraging milestone that provides further evidence that we have a very large and potentially company-making asset at Lake Throssell.”

“The lake trenching and test pumping program has delivered highly encouraging results, providing invaluable data on the key characteristics of the surficial aquifer.”

The Lake Throssell project lies near the terminus of extensive palaeo-valley catchment areas or ancient river valleys that extend for more than 500km and are underlain by potassium-bearing source rocks – granites, sandstones and salt diapirs.

Brine solutions carrying potassium mineralisation have been concentrating in the palaeo-valleys and salt lakes for millions of years, Trigg says.

Lake Throssell hosts a palaeo-valley that spans up to 5km wide, 100m deep and about 36km along strike within the company’s central granted tenement.

Demonstration of the abstraction potential of the lake surface aquifer by the brine field trial now paves the way for the company to refine its surficial aquifer resource modelling and generate the desired indicated status for the Lake Throssell mineral resource.

Trigg recently tipped about $3.4 million into its coffers after closing out an oversubscribed capital raise, expanding the company’s issued capital structure to a tightly held 114.5 million shares not including options.

The bulk of the funds from the renounceable rights issue are earmarked to go towards the Lake Throssell mineral resource upgrade and the recently commenced scoping study.

Is your ASX-listed company doing something interesting? Contact: matt.birney@businessnews.com.au