Kenorland Minerals Ltd (TSX-V:KLD) has announced the results of preliminary metallurgical testing at the Regnault gold system of its Frotet project in Quebec.
Preliminary metallurgical test work at the project, which is held in a joint venture with Sumitomo Metal Mining Canada Ltd, was begun after the completion of a drill hole that intersected 29.08 meters (m) at 8.47 grams per ton (g/t) of gold, including 11.13m at 18.43 g/t of gold.
The study included the analysis of mineralogical characteristics and the preliminary assessment of old-silver recovery through cyanide amenability of the Regnault ore, the company said.
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Specifically, about 60 kilograms of material from 27.1m was processed to make a representative sample of the R1 mineralized zone for characterization. Samples were crushed, mixed and split for x-ray diffractometry and mineralogical analysis.
The composite head grade was 15.9 g/t gold and 24 g/t silver, similar to the original composite analyzed by Bureau Veritas Commodities, the company said. MLA analysis identified gold-silver-telluride, electrum and native gold as the main gold and silver-bearing mineral species.
Baseline test procedures were conducted by using four samples which were ground to 100 micrometers and underwent oxygen purging for 24 hours, followed by cyanide leaching for 48 hours at 0.5 grams per liter (g/L) of sodium cyanide (NaCN) concentration.
Baseline conditions indicated gold extraction of 86.9% and silver extraction of 68.2% on average with cyanide consumption rates between 1.1 and 1.5 kilograms per ton.
Upon completion of the baseline tests, the effect of extended leaching duration (72 hours), higher dissolved oxygen content (30-35 mg/L), higher NaCN concentration (1g/L), and finer feed size (75 micrometers) were investigated.
Gold recoveries increased to 89.1-89.9% with extended leaching, finer grind size, and increased dissolved oxygen while the increased NaCN concentration only marginally improved recovery. Silver recoveries increased to 81.5-86.2%, with the increased dissolved oxygen and NaCN concentration while extended leaching marginally improved recoveries, the company said.
This suggests that gold extraction is best improved with finer grinding and extended leaching, likely due to an increase in liberated gold grains and complete dissolution of coarse gold. Silver extraction is best improved with extended leaching and higher dissolved oxygen content, likely due to the leaching kinetics of the silver-bearing tellurides.
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