:: Sepon Copper project on Track for First Metal Production

Despite the many logistical challenges, the fast-track Sepon Copper project in Laos is on target to meet its tight schedule. Water commissioning of the plant is nearing completion, after which the plant will be handed over for commissioning of ore processing to a combined contractor/operations team to meet the deadline for the production of the first copper metal.

The project is being carried out by a joint venture between Bateman and Ausenco Limited (50/50), known as KDG, for Lang Xang Minerals Limited (LXML), a Lao-based gold and copper producer that is wholly owned by Oxiana Limited. The project, to develop the copper-hydrometallurgical process plant close to the Khanong copper deposit in the Vilabouly district of the Lao Savannakhet province, comprises phase 2 in the development of the copper and gold resources in the Sepon Project Development Area.

The project team has, in the past two years since the project's commencement in 2003, delivered consistently against substantial odds, an achievement that has required innovation in technology and plant design and detailed implementation planning. In addition, a key ingredient in the success of the project has been the committed partnership between KDG and the client, LXML.

Of the many challenges facing the site team were the need to carry out much of the construction during an intensive wet season, and the transportation of huge loads of materials and equipment over considerable distances. The largest piece of equipment on the project, the 162 t autoclave, was offloaded at site at the height of the wet season after delivery through Thailand, across the Mekong River by barge and across 43 Laotian bridges, 22 of which required reinforcing. In addition, KDG managed the delivery and construction of

• 2 600 t of structural steelwork obtained from Thailand;
• 63 km of piping including specialised titanium and SAF materials;
• 260 km of cabling; and
• 25 000 m³ of concrete.

In total, 1 365 loads of materials were transported via Bangkok along a 967 km supply route, the last 42 km of which is a dirt road.

The plant, the design of which is based on a definitive feasibility study by Bateman, incorporates a two-step leaching process which is expected to recover more than 90 % of the copper in the ore. Processing some 1,3M t/yr of chalcocite-clay run-of-mine ore at an average grade of 5 % copper, the plant will produce a nominal 60 000 t/yr of copper cathode.