PERTH (miningweekly.com) – Copper miner PanAust on Thursday reported that its Phu Kham operation, in Laos, had exceeded expectations during the three months ended March, producing some 15 772 t of copper.
The operation processed ore at an annualised rate of 13.8-million tons, above the 12-million tons a year nameplate capacity, despite a planned three-day mill maintenance shutdown in January and a further three-day unscheduled downtime.
PanAust said in its quarterly performance report that the above-budget copper and gold production results during the quarter provided the company with a solid foundation to meet the production guidance for the full year.
During 2012, the Phu Kham operation would produce between 63 000 t and 65 000 t of copper in concentrate.
Copper production at the Laos operation was expected to progressively increase over the next three years, following the completion of the upgrade project later this year, and the increased recovery project in the second half of 2013.
Production would rise to between 65 000 t and 70 000 t in 2013, and to between 70 000 t and 75 000 t by 2014. Gold and silver production from Phu Kham would also increase as a consequence of these initiatives.
The current upgrade project would increase the ore processing rate from 12-million tons a year to 16-million tons a year and would improve metal recoveries through an increase in grinding and flotation capacity.
The aim of the project was to allow copper-in-concentrate production to be sustained on a lower-grade mill feed.
The increased recovery project would, in turn, increase average yearly copper and gold production by around 5 000 t and 7 500 oz respectively.
The project stems from a two-year evaluation of various methods to improve metallurgical recoveries in Phu Kham. Plant-scale test work confirmed that by incorporating a strategy of less selective rougher flotation in combination with additional regrind and cleaner flotation capacity, life-of-mine recovery rates for both copper and gold could be increased by six percentage points.
Meanwhile, PanAust also noted that first silver dore from its Ban Houayxai operation, also in Laos, would be poured in the second half of April, with ramp-up to steady-state production expected in the June quarter of this year.
PanAust was targeting yearly production of some 100 000 oz of gold and 700 000 oz of silver, with total costs for the project estimated at $195-million.