Metallurgical testwork of material from the Paris project in South Australia has yielded improved silver recoveries for owner Investigator Resources (ASX: IVR).
Testing by ALS Geochemistry in Tasmania targeted the breccia transitional (BT) metallurgical domain component of the project which comprises 54% of the total mineral resource.
A weighted average silver recovery of 78% across the board was returned, representing a 4% improvement on similar work done in 2018.
Revised grinding and cyanide leach testwork improved recoveries in the BT domain from 65% to 72%.
When applied to the total mineral resource, the enhancement of recovery for the BT domain – which remains the largest single component of the resource and with the lowest recovery – increases the average recovery for the project from 74% to 78%.
Investigator said there is potential for greater increases with further optimisation of flotation tail cyanide leach in future testwork.
Investigator managing director Andrew McIlwain said the results are “very encouraging” for the project.
“With the BT domain comprising a large part of the Paris resource, a clear opportunity has existed for us to shift the economics of this project by improving the recovery,” he said.
“We are particularly encouraged that there are opportunities which may be explored to further incrementally improve metal recoveries within the BT and other domains.”
Located approximately 70km north of Kimba along the Eyre Peninsula, the Paris project remains the highest-grade undeveloped primary silver discovery in Australia.
It hosts a JORC-compliant resource estimate of 9.3 million tonnes at 139 grams per tonne of silver and 0.6% lead for 42 million ounces of contained silver and 55 kilotonnes of contained lead.
Investigator believes the deposit could be amenable to open pit mining with an updated resource estimate due to be finalised once results from a recent infill drilling campaign have been incorporated.
Mine design and optimisation will be included in a pre-feasibility study scheduled for completion in July.