Sleeper mine produced gold at $103 (US) per ounce in ’88

In the company’s annual report, Amax Gold President Charles Scott predicted that Sleeper’s gold output would climb to 250,000 oz this year because of a recently completed $17-million expansion program.

That program included extensive overburden stripping around the Sleeper and Wood pits to allow mining of a newly delineated orebody. Existing grinding, leaching, carbon handling, and refining facilities were expanded to increase mill throughput by almost 50% to 1,500 tons per day.

Heap leach capacity was expanded to five million tons per year and additional equipment was purchased to increase the mining rate by 63% to 13 million tons annually, he said.

Gold recoveries averaged 94.5% based on a daily throughput of 1,037 tons or 380,000 tons for the year. The average head grade for milled ore was 0.48 oz gold and 0.024 oz for heap leach material. At year- end, conventional reserves stood at 3.4 million tons grading 0.32 oz gold along with 44.9 million tons of heap leach material averaging 0.021 oz gold.

Described by the company as its “most important physical asset,” the Sleeper mine is “not the only story at Amax Gold,” Scott said. A decision was made last year to develop the Wind Mountain project 75 miles northeast of Reno and it should produce 42,000 oz gold per year beginning this year.

Although several other companies viewed the project as uneconomic, Scott said a re-interpretation of data by Amax Gold suggested otherwise. A mining and processing plan has been adopted to optimize production. Precious metal precipitates from Wind Mountain will be shipped to Sleeper for processing into dore bullion. Production is expected to begin in the second quarter. The heap leach operation has 15.1 million tons of reserves averaging 0.021 oz, but there is considerably more potential, the company claims.

Amax Gold has a 28.5% interest in the Waihi mine on the North Island of New Zealand. Production this year is expected to be 57,000 oz gold and 280,000 oz silver, 28.35% of which will accrue to Amax Gold. The conventional treatment plant at Waihi uses carbon-in-pulp technology and last year it processed material grading 0.07 oz gold per ton. Production costs were $284 per oz or $352 all included.

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