By Business Reporter
AIM-listed copper miner Weatherly International’s Tschudi mine has produced 3 236 tons of the metal in the first three months of 2017, to March 31, which is 24 percent below nameplate capacity.
The mine noted that this was a result of slower than anticipated leach rates for mixed oxide and sulphide ore, stacked during the latter part of 2016 and early 2017, which was further exacerbated by above-average seasonal rains during the quarter, which prevented the short-term acceleration of mining and stacking to compensate.
“However, as rain delays reduced, heading into March, the rate of stacking copper metal improved notably, and these improved rates of stacking copper are expected to be sustained going forward,” the mine said in its latest output report.
Weatherly still expects to produce between 14 500 and 15 000 tons of cathode for the financial year to 30 June, as the rate of leaching is expected to recover during the fourth quarter.
Late last year, the mine’s management expressed huge disappointment over how high groundwater had negatively affected their third quarter throughput, thereby spoiling the company’s record of beating its own guidance.
“We are disappointed that we were unable to anticipate such high groundwater inflow rates at Tschudi, which had consequently spoiled the company’s record of beating our guidance,” Weatherly Chief Executive Officer, Craig Thomas, said at the time.
Tschudi is a low-cost open-pit mine, extracting oxidised copper ore that is treated through heap-leach, solvent extraction and electro-winning. Environmental approval for the Tschudi mine was granted in April 2013 and groundbreaking was held in November the same year. Civil construction works at the mine site began in April 2014 and the first copper was produced in October 2015.
Tschudi is expected to produce an average of 17 000 tons of copper per annum, during its 11-year life period. The deposit is expected to create more than 500 jobs.
The ore body of the Tschudi mine is located in the basal sandstones and minor conglomerates of the Malden Group. The deposit is open-ended at the south-west and has a strike length of approximately 2 500m.
Oxide mineralisation at Tschudi occurs up to a depth of 70m below the surface. Beyond the 70m level, a transitional zone of mixed sulphide-oxide mineralisation then extends to a depth of approximately 110m, followed by a sulphide zone.
Copper mineralisation in the oxide zone is mainly composed of malachite and minor chalcocite. The mineralisation is disseminated through a sandstone and conglomerate unit, lying above a dolomite unit. The sulphide zone contains chalcocite and bornite, while the transitional zone contains a combination of chalcocite and bornite.
As of December 2015, the mine was estimated to contain reserves of 24.4 million tons of ore grading, at 0.85 percent copper, containing 207,000t of copper. -Additional reporting by Mining Weekly
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