China’s Chifeng Jilong Gold Mining Co last month, on May 16, started processing oxide gold ore from the Sepon mine in Laos, operated by subsidiary Lane Xang Minerals Ltd (LXML) which is the first time the project has produced gold in over six years after MMG, the previous owner, stopped producing gold at the mine in late 2013, choosing to focus on copper.
Gold treatment was stopped at the time due to low reserves, low grades and low recovery. Gold exploration is now ramping up, although the principal reason that gold is now viable again is that with oxide copper reserves being depleted, some of the plant and infrastructure used for processing copper, including two pressure oxidation circuits, can now be used to treat primary gold ore.
The LXML team spent 11 months refurbishing the oxide ore plant and last month successfully completed wet commissioning and first ore processing. On the 23 June, the LXML team celebrated their first gold pour and they continue to ramp up gold production ahead of forecast, according to Paul Harris, the company’s General Manager.
Chinese flotation technology supplier BGRIMM Group has been a key player in the primary ore processing design, responsible for flotation tests, and the engineering design for a new flotation plant, as well as the supply of new flotation cells. Paul Harris also stated that commissioning of the new flotation plant, and processing of primary gold ore was on track to commence during the middle of the third quarter this year.
The restart of the gold production realises Chifeng LXML’s strategy of achieving growth through three parallels, namely the parallel production of gold and copper, the parallel processing of oxide and primary ores, and the parallel mining of both open cut and underground mines.
Oxide and primary gold ore will primarily come from open pits, but there may also be ore produced from an underground mine pending further investigation into the feasibility of underground mining at Sepon. Currently there are seven copper pits and three gold pits being actively mined; they are all separate. Sepon is planning on having no less than nine gold pits operating in the future, and also plan to develop an underground mine in the near future to supplement the open pit ore.
LXML will also continue to produce copper through the limited remaining copper plant capacity, while studies and test work are underway to support the feasibility of heap leach treatment of low grade copper ore.