Aussies as good as gold in Laos

Australian expertise has been showcased in the development of the Phu Kham Copper-Gold Operation in Laos. PanAust Limited, which has a 90% stake in the operation, appointed Brisbane-based Ausenco Limited to design and engineer the project on an engineering, procurement and construction management (EPCM) basis.

The Phu Kham copper-gold deposit is located approximately 120 km north of the Lao capital, Vientiane. The deposit lies beneath an oxide gold cap, which is the ore source for the existing heap leach gold operation which will be phased out when the gold cap reserve is depleted next year. The site has been designed for the production of copper-gold concentrate from the main deposit and consists of a crusher, SAG and ball mill, with 21 float cells and associated thickener, filter and tailing processes.

Production began at the site in April this year, several months ahead of schedule and within the US$241m capital budget, paving the way for PanAust to take advantage of record copper prices.

In 2009, the first full year of production, the operation is scheduled to process 12 million tonnes through a conventional flotation process to produce 240,000 t of concentrate, containing 60,000 t of copper, 60,000 oz of gold and 600,000 oz of silver. The operation effectively doubles Laos’ production of copper, which will be exported for custom smelting. However, PanAust has already committed to expand throughput to 16 million tonnes per annum by the start of 2010.

The project presented Ausenco with a variety of challenges, mainly arising from the tight schedule and the logistics of working on a site in a fairly remote location. The choice of process control system was a critical one. “We used three main criteria to select the control system: the ability to deliver on this fast-tracked project, the quality of the control system and price,” Phil Ebzery, Ausenco’s lead instrumentation and control engineer, said. “Any delays in getting the control system established and fully commissioned had the potential to directly impact on the project schedule, so the suppliers’ quality procedures and the expertise of their staff were really put under the microscope.

“In the end, we chose Yokogawa’s Centum CS3000. Because it has a fully integrated architecture, it takes less engineering time to program the system, less time to make ongoing changes and generally better internal system diagnostics.”

In addition to supplying the control system, which has about 4500 I/O, Yokogawa was responsible for its design, configuration, testing and commissioning, as well as panel supply. The design work included developing ‘intelligent’ sequencing to ensure consistent plant operations and logic for each drive type to simplify procedures for upgrading and updating the system as required.

Most areas of the plant were fully commissioned by March, with the first ore feed on 29 March and first concentrate production on 28 April. The operation then worked towards achieving steady-state operations through May and progressively ramping up throughput to design rates over the following six months.

Yokogawa Australia engineers were involved from the start of the project, and found it very satisfying to see it all the way through to the end. During six weeks in Laos, they worked closely with the commissioning team from Ausenco to test run all the equipment, conduct extensive loop checks and advise on the interfacing of a variety of equipment to the control system. They customised the operator interfaces to meet specific needs and provided training for the local mine operators, who can now implement minor revisions and undertake routine maintenance of the control system. They will also have access to expert support from Yokogawa’s 24/7 service centre in Bangkok.

“All in all, we found Yokogawa Australia to be a very easy company to work with. The attitude across the board, from the managing director to the engineers working directly with us, was excellent,” Ebzery said.

Yokogawa Australia Pty Ltd
www.yokogawa.com.au