JOHANNESBURG (miningweekly.com) – TSX-listed gold exploration company Pilot Gold on Monday reported that its initial metallurgical test results for its Kinsley Mountain property “clearly demonstrated” that it contained high-grade material with “excellent gold recoveries”.

Pilot Gold CEO Matt Lennox-King said the results, which boasted concentrate grades of up to 312 g/t gold, “opened the door to [the] consideration of low capital and operating cost alternatives for potential mining of high-grade sulphide mineralisation at Kinsley".

The company noted that initial geochemical analyses of mineralised intercepts, including characterisation of carbon and sulphur, inductively coupled plasma analysis and determination of the solubility of gold in cyanide, demonstrated that the concentration of gold relative to sulphur was high compared to other sediment-hosted, Carlin-style gold deposits.

Concentrate grade ranged from 98.6 g/t to 312 g/t gold. At an estimated $1 200 gold price, the contained value of these concentrates range from $3 800/t to $12 000/t. “Therefore, cost for on-site processing or shipping and processing concentrate at a commercial smelter or a local Nevada refractory treatment facility would only represent a small portion of the overall concentrate value,” the company pointed out.

Further, petrographic work showed that pyrite, within which the gold was believed to be resident, was relatively crystalline, dense (nonporous) and that there was a small quantity of sulphides that were less than 20 μm.

The data and observations also demonstrated potential for producing a high-grade flotation concentrate, which could then be evaluated for direct sale to commercial smelters or potentially to any one of several Nevada mine operators that were able to process refractory concentrates through roasting or autoclaving, for final gold recovery.

Four samples representing gold grades from 4.23 g/t to 20.3 g/t gold and a range of cyanide solubility levels were subjected to rougher and scavenger flotation testing over myriad of conditions, including variations in grind size, followed by cyanidation of the flotation tails.

Combined concentrate recoveries ranged from 76% to 89.6%. Combined with cyanidation of the flotation tails, the total recovery increased to 89% to 95%.