Terrain Minerals Limited has confirmed that mineralisation from the Lightning deposit at its 100%-owned Smokebush Project in Western Australia is amenable to conventional gravity and carbon-in-leach processing, achieving overall gold recoveries of up to 93.7%.

The metallurgical testwork program, conducted by Independent Metallurgical Operations in Perth, evaluated three composite samples representing the range of grades and mineralisation styles intersected at Lightning. Assayed head grades for the composites stood at 2.55 g/t gold for Composite 1, 0.93 g/t gold for Composite 2, and 1.47 g/t gold for Composite 3.

The testwork yielded gravity recoveries ranging from 30.6% to 50.8% ahead of leaching, using a Knelson concentrator. The evaluation confirmed that overall recoveries were achieved at a standard grind size of P80 75 microns, meaning no fine grinding is required. Under baseline conditions, overall recoveries reached 87.0% for Composite 1, 92.1% for Composite 2, and 93.7% for Composite 3.

The analytical program also established that total carbon across all three composites sat at or below 0.03%, while organic carbon remained at or below 0.02%. Sulphide sulphur ranged from 0.74% to 1.35%. These chemical parameters demonstrate a free-milling feedstock with no refractory or preg-robbing behavior. The material therefore avoids the capital and operating costs associated with specialized processing routes such as roasting, pressure oxidation, or bio-leaching.

Furthermore, testwork showed that recoveries were delivered within normal plant residence times. Australian gold plants typically apply a total leach residence time of 24 to 36 hours. At the 24-hour mark under optimized conditions, the composites had already returned recoveries of 82.1%, 91.7%, and 95.3% respectively.

The metallurgical results provide a solid technical platform to advance Lightning toward study-level work. The findings follow the delivery of a maiden mineral resource estimate of 677,000 tonnes at 2.5 g/t gold for 54,000 ounces of gold in July 2026. Terrain Minerals intends to conduct further drilling across the deposit to upgrade the current maiden mineral resource estimate to the Indicated category and expand the overall resource inventory.

Read the full announcement: Metallurgy Confirms Lightning Gold Up to 93.7% Gold Recovery