WA-focused gold explorer Saturn Metals Ltd (ASX:STN) has shown that recoveries of up to 88 percent can be achieved with ore taken from its Apollo Hill project in the Eastern Goldfields, and that this can be done without milling.
Five leach tests were conducted on samples of Apollo Hill ore yielded from diamond drilling, with this representing the deposit’s main type of ore – fresh basalt, dolerite and mafic schist rock types, and grading between 0.23 and 1.49 grams per tonne of gold.
After being prepared through closed-circuit high pressure grinding roll (HPGR) and crushed to a P100 size of 4 milimetres, the ore yielded average recoveries of 88 percent, which the company said was an impressive result when compared to heap leach recoveries.
Saturn had previously shown that recoveries of 78 percent were possible from ore with the HPGR crush size of 8 milimetres P100, and the improved results further validate the metallurgical quality of Apollo Hill.
Saturn Managing Director Ian Bamborough said the testing had provided strong indicators of what the project could achieve.
“These spectacular and consistently high gold recovery results, from a representative Apollo Hill sample set, provide ongoing evidence for the application of simple cost-effective heap leach processing at Apollo Hill,” he said.
“The metallurgy of Apollo Hill is a competitive advantage. It provides an economic head start for the deposit which ultimately converts to leverage on the magnitude of the deposit and its efficient development.
“The company is progressing with our studies towards production.”