COPPER COBALT GOLD PROJECT FLOWSHEET DEVELOPMENT

摘要

Cobalt is present as cobaltite, copper is present as chalcopyrite and the gold is predominantly associated with the sulphide minerals. The similar nature of the sulphide minerals, together with the gold association, has allowed a very simple beneficiation process and production of a bulk concentrate. These results suggest excellent potential for the production of a concentrate for hydrometallurgical processing. Testwork was conducted on a composited sample of drill core from the Company's recently completed drilling program at the Cobalt Ridge prospect. Mineralisation tested included grades representative of what is considered the "background" grade for the main lode within the cobalt deposit. The assayed grade of the sample was 0.14% cobalt, 0.32% copper and 0.09 ppm gold, providing a variation to the previously tested high-grade mineralisation. Simple bench scale rougher flotation tests yielded excellent recoveries of 93.6% cobalt and 98.45% copper. A large scale rougher-regrind cleaner flotation circuit achieved 78.7% cobalt and 91.6% copper recoveries in 2.92% of the rougher feed mass. The cleaner concentrate graded 3.31% cobalt, 9.28% copper and 2.73 ppm of gold. This concentrate was used for the downstream testwork.The concentrate was subjected to pressure oxidation (POX) followed by solvent extraction to recover copper and cobalt. The residue was cyanide leached to recover gold. Solvent extraction shake tests were conducted to recover cobalt and copper. A flowsheet was developed tailored to the ore characteristics to recover cobalt sulphate, copper sulphate and gold.