FLOTATION test work on diamond core from the Prospect 150 area of Geopacific Resources Kou Sa Copper-Gold Project has produced exceptional recoveries. The work showed that the concentrate is very clean and does not contain deleterious elements.
The initial metallurgical test work was aimed at producing a float concentrate of copper, gold and silver from the mineralization. The test work was combined with an optical mineralogy study to allow optimal reagent selection.
Geopacific commissioned Independent Metallurgical Operations for the initial test work. More than 36kg of core was selected from mineralized intervals of five PQ and HQ diamond drill holes to form a master composite for tests. Selected intervals were also sent for an optical mineralogy study to determine metal and mineral associations. The assay head grade of the master composite was 3.05% copper, 3.83 grams/tonne gold and 21.5 grams/tonne silver.
The study confirmed other work by Geopacific that a significant proportion of the gold and silver occurs as telluride minerals, which are generally regarded as indicative of a deep seated source for mineralization and are important in several major goldfields, including Kalgoorlie, Cripple Creek in Colorado and Emperor in Fiji.
In this round of tests, five flotation tests were conducted testing grind sizes, collector concentrations and pH with the aim of optimizing recovery of all economic metals into the highest grade possible.
The results indicate normal recoveries for all metals but particularly gold and silver. The high precious metals recovery is due to their association with the tellurides’ excellent float characteristics. Chalcopyrite mineralization also produces a very clean concentrate that is highly sought after by downstream processors.
Test two resulted in 98.4% copper recovery, 94.1% gold recovery, 91.1% silver recovery and 22.8% mass recovery. Each recovery test comprised four rougher stages. The majority of copper reported to stage 1 with the other stages all adding to total recovery. Further optimization test work studies are expected to optimize grind, reagent use and improve recovery.