Saturn Metals Ltd (ASX:STN) has achieved strong first-pass results in a laser ore sorting test of a 24.2-kilogram composite sample of mineralised material from its Apollo Hill Gold Project in Western Australia.
The results highlight the deposit’s amenability to this type of mineral processing upgrade, showing mineralised quartz can be efficiently separated from non-mineralised host basalt.
Further test work is planned to optimise the application of ore sorting technology as a processing option for the project.
Saturn managing director Ian Bamborough said this was a very important breakthrough for Apollo Hill, which currently contains a mineral resource of 20.7 million tonnes grading 1.0 g/t gold for 685,000 ounces of gold.
He said: “Positive ore sorting results have the potential to deliver a step change in the feed grade of material delivered into any mineral processing circuit.
“Subject to further positive results, we may have the potential to significantly improve options for the economic development of Apollo Hill.”
Highlighted outcomes from the test work include a 1.5 times upgrade to the grade of the sample, from 0.78 g/t gold to 1.2 g/t, as well as strong gold recovery of up to 91.9% with only two ore sorting passes.
A 28% volume reduction was achieved, removing a significant portion of waste rock and marginal material.
The company notes that only 0.55% of gold in the sample was lost to fines in preparation for ore sorting, a process involving crushing and wet screening to plus-10 millimetre ore sorting size.
This low figure is considered a positive result as loss of metal to fines can otherwise render the process ineffective.
Ore sorting 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 processing circuits or increase gold milling capacity, both of which would positively impact project economics.
An ore sorting treatment of higher-grade material from Apollo Hill could also lead to truck and toll treatment options for the deposit.