By year-end, Spokane-based
A bankable feasibility study is under way and scheduled for completion later this year; it will incorporate work from Kvaerner Metals, Vector Colorado, Pincock Allen & Holt, and SGS Lakefield Research Canada.
Kvaerner is evaluating various production options, ranging from 20,000 to 70,000 tonnes per day. The base-case option examined in the prefeasibility study was for a 50,000-tonne-per-day operation capable of producing an estimated 362,000 oz. gold and 46 million lbs. copper annually at a cash cost (net of copper credits) of US$153 per oz. gold.
Lakefield is carrying out tests to confirm gold and copper recoveries using flotation, and to produce sufficient copper-gold concentrate for subsequent testing using the pressure-oxidation process.
Kvaerner, meanwhile, is studying three processing options, each of which begins with crushing, grinding and flotation of sulphide concentrates. One option is direct shipping of the gold-copper concentrates to an off-site smelter; another is processing of concentrates through a high-temperature pressure-oxidation (HTPOX) process to produce copper cathodes on site; and the third is processing concentrates through the Cominco Engineering Services (CESL) process to produce copper cathodes on-site.
The feasibility study will select and then examine only two of these options. The preferred options will be announced shortly. President Douglas Belanger notes that, owing to significantly reduced long-term concentrate treatment and refining charges, “the bankable study may ultimately conclude that processing of concentrates at an off-site smelter is the most economic alternative.”
A previous study by Behre Dolbear examined in-pit reserves using the traditional smelter and CESL processes for treating copper concentrates. The CESL pit design was based on reserves of 328.5 million tonnes grading 0.7 gram gold per tonne and 0.15% copper. The smelter-pit design reduced reserves to 256.6 million tonnes at 0.8 gram gold and 0.13% copper. These estimates were based on a gold price of US$325 per oz. and a copper price of US85 per lb.
Brisas also has resources in all categories. In the next few months, the company will release updated reserve and resource calculations incorporating results of a nearly completed, 15,000-metre drill program.
On the permitting front, Gold Reserve has secured rights to mine both copper and gold, as well as an operating permit.
An operating permit is required before a company can apply for environmental permits. Gold Reserve is preparing its environmental impact statement, which it will submit to the Ministry of Environment.
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