PERTH (miningweekly.com) – A revised life-of-mine (LoM) plan for PanAust’s Phu Kham copper/gold project, in Laos, would see yearly production increase by about 30 000 t of copper in concentrate.

PanAust undertook a comprehensive review of the LoM plan for Phu Kham, following the revision of the 2013 and 2014 mine plan earlier this year, in order to prioritise mining on the interim west wall of the openpit operation.

For 2013, the Phu Kham operation was expected to produce between 62 000 t and 65 000 t of copper in concentrate, ramping up to between 65 000 t and 70 000 t by 2015 as benefits from a full year of the increased recovery project kicked in.

Between 2016 and 2019, increasing head grades would cause copper-in-concentrate production to rise to peak levels of around 90 000 t/y.

Gold grades would be variable during this time, with the mine producing between 60 000 oz and 80 000 oz in concentrate, through to the end of the decade.

“Benefits are being realised from the capital invested in the processing plant at Phu Kham over the past two years, with processing rates of over 18-million tonnes a year - well above the design of 16-million tonnes a year - and metallurgical recoveries exceeding those predicted for each ore type that has been treated,” said PanAust MD Gary Stafford.

From 2014, the average LoM strip ratio at Phu Kham would be around 1:2:1 and openpit material movements would increase between 2014 and 2016 by around 50-million tonnes a year as the LoM waste prestripping and stripping requirements peak, and some low-grade ore is stockpiled.

Further upside to production and the mine life at Phu Kham could also be realised by the current resource development programmes under way, said Stafford.

In addition, a prefeasibility study, scheduled for completion in December, was also focusing on defining an ore reserve at the KTL deposit, which could truck ore to Phu Kham.

The KTL study would assess the options of further increasing the copper and gold production at Phu Kham from 2017 for a four- to seven-year period, either through additional processing or the displacement of lower-grade feed.