Saturn Metals is heralding the first pass results of a laser ore sorting test at its Apollo Hill gold project, near Leonora in the Western Australia goldfields, saying there is potential for using this type of mineral processing upgrade on a future mining operation.
Testing using a STEINERT Fines KSS L machine showed mineralised quartz can be efficiently separated from non-mineralised host basalt, according to the company, with the first sorting test achieving a 1.5x upgrade to the grade of a sample, taking material from 0.78 g/t Au to 1.2 g/t Au. Alongside this was a strong gold recovery of up to 91.9% with only two ore sorting passes.
Other notable results from this test work included a 28% volume reduction, which was achieved through the effective ejecting of a significant portion of waste rock and marginal material and, importantly, only 0.55% of the gold in sample was lost to fines in preparation for ore sorting (crushing and wet screening to +10 mm ore sorting size). “This low figure is considered a positive result as loss of metal to fines can otherwise render ore sorting ineffective,” the company said.
Saturn explained: “Ore sorting, particularly with strong recovery results as seen in the test conducted at Apollo Hill, can result in a more efficient mineral processing solution being developed for mining projects, with smaller tonnages of higher-grade material being beneficiated for mineral processing. This can potentially reduce the size and cost of mineral processing circuits, or increase gold milling capacity, and, in turn, positively impact overall project economics.”
Successful ore sorting treatment of selective higher-grade material from Apollo Hill could also lead to truck and toll treatment options for the deposit, according to the company.
Following these initial results, the company is planning further test work to refine and improve the application of ore sorting technology at Apollo Hill, it said.
Saturn Managing Director, Ian Bamborough, said the results were a “very important breakthrough” for project, which currently contains an indicated and inferred mineral resource of 20.7 Mt grading 1 g/t Au for 685,000 oz of gold.
“Positive ore sorting results have the potential to deliver a step change in the feed grade of material delivered into any mineral processing circuit,” he said. “Subject to further positive results, we may have the potential to significantly improve options for the economic development of Apollo Hill.”