PERTH (miningweekly.com) - South Australian copper miner Oz Minerals on Monday reported a 43% increase in the mineral resource for its Carrapateena deposit.
The project was now estimated to host some 292-million tons of resource, at 1.29% copper and 0.48 g/t gold, of which 90-million tons was classified as inferred, and 202-million tons as indicated resource.
“Since completing the acquisition of the Carrapateena copper/gold project in South Australia, in May 2011, we have improved the inventory of mineral resource by some 43% and through a very targeted infill exploration drilling programme, increased our confidence in the resource, as evidenced by the upgrade from inferred to indicated status,” said MD and CEO Terry Burgess.
He noted that the recent drilling had also provided Oz with further evidence that the Carrapateena resource was a superior deposit, with the recognition now that the mineralisation extended beyond the 2011 resource.
“The focus during 2013 will be to commence the exploration decline using a tunnel-boring machine to allow further geotechnical works to be completed, and assess the best mining technique for this resource.”
Meanwhile, Oz on Monday reported that the contained copper resource at its Prominent Hill operation had remained largely unchained for the year ending December, despite mining depletion, as a result of the increase in higher-grade underground resources.
The Ankata underground resource showed a 25% increase in tonnage and a 14% and 11% increase in copper and gold grades respectively. Ongoing underground diamond drilling has seen the resource increase by some 3.3-million tons, for 32 000 t of copper and 14 000 oz of gold.
The Ankata reserve also increased by 2.9-million tons, for 30 000 t of copper and 16 000 oz of gold, which represented about two additional years of mining from the underground orebody, Oz said.
During the 12 months since the last reserve statement, Oz mined some 9.8-million tons of ore, at 1.22% copper and 0.6 g/t gold from the Malu openpit operation. The Malu underground resource decreased marginally in copper metal, by only 2%, and by 5% in gold, as a result of a change in the geological interpretation near the Kalaya–Malu resource boundary.
Total mineral resources for Prominent Hill have reduced from 272.7-million tons, at 0.98% copper and 0.7 g/t gold for 2.6-million tons of copper and 3.2-million ounces of gold, to 264.8-million tons, at 0.99% copper and 0.7 g/t gold, for 2.6-million tons of copper and 5.9-million ounces of gold.
The total ore reserve had decreased from 72.3-million tons, at 1.1% copper and 0.6 g/t gold for 818 000 t of copper and 1.5-million ounces of gold, to 69.8-million tons, grading 1.1% copper and 0.6 g/t gold for 748 000 t of copper and 1.3-million ounces of gold.