Integra Mining joined the ranks of gold producing companies in late September 2010 when it poured the first gold at its Salt Creek processing plant on its Randalls gold project 60 km east of Kalgoorlie, Western Australia. The Salt Creek plant is initially processing 3.6-g/mt ore from the project’s two Phase 1 open-pits, Salt Creek and Maxwells. The plant is ramping up to a planned 90,000-oz/y gold production rate, which will be maintained for the first 15 months of operation.
Cash costs during Phase 1 are forecast at A$574/oz, providing a margin of nearly A$800/oz at current gold prices.
Studies are in progress for the start of early underground production from the Randalls project’s high-grade Santa and Cock-eyed Bob gold deposits, with underground production from the Maxwells deposit to begin after mining of the Maxwells open-pit is complete. Phase 2 production also may incorporate the recent Majestic gold discovery, which is demonstrating excellent potential for an additional open pit.
Introduction of underground production is expected to lift Randalls production to above 100,000 oz/y without modification to the processing plant. Over the medium term, Integra is targeting a 50% plant throughput upgrade to 1.2 million mt/y in conjunction with Phase 2 open-pit and underground mining to lift total gold production to more than 140,000 oz/y.
The strong outlook for Randalls Phase 2 has been underpinned by bumper results from drilling at the Santa deposit, which is rapidly emerging as a source of both open-pit and underground ore. Santa drill intercepts recently included 4 m at 34.1 g/mt gold, 4 m at 17.4 g/mt gold and 2.1 m at 46.7 g/mt gold. The high-grade mineralization extends over a 2-km strike length and to a depth of 400 m and remains open along strike and at depth.
Drilling at the Maxwells and Cock-Eyed Bob deposits has also revealed strong potential for high-grade underground production. Integra believes there is no geologic reason why the high-grade gold mineralization at the Maxwells, Cock-Eyed Bob and Santa gold deposits does not continue to 1 km depth or beyond.