Name of the project and location
Bogoso sulphide expansion project, south-west Ghana.

Project description
The project scope includes the design, construction and commissioning of a 3,5-million-ton-a-year gold-processing plant. The project includes a BIOX bio-oxidation circuit. The new sulphide-processing plant will be built within the same complex as the existing 1,5-million-ton-a-year oxide-processing plant at Bogoso.

The sulphide plant is expected to produce between 260 000 oz/y and 290 000 oz/y of gold.

Value
The capital cost for the construction is estimated at between $115-million and $125-million, inclusive of the cost of expanding the mining fleet.

Duration
The project is expected to take between 15 and 18 months to complete.

Breakdown of main contracts
GRD Minproc secured preferred contractor status for the engineering procurement and construction contract for the project. Group Five will be responsible for the installation of 650 t of structural steel.

Client
Golden Star Resources.

Latest developments
According to Golden Star Resources, the 2 200 t/h gyratory crusher was commissioned in October 2006 and is fully operational, crushing low-grade carbonate ore for nonrefractory circuit feed.
The new ball mill was commissioned in October 2006 and the semiautogenous grinding mill was commissioned in December 2006. Both mills are operating and providing nonrefractory slurry feed for the carbon-in-leach circuit (CIL).
The existing CIL plant continues to process nonrefractory ore. The new CIL circuit is operational and processing nonrefractory ore, thereby increasing throughput capacity.
The BIOX(R) Module 1, Reactor Tanks 1 and 2 are operational, using previously stockpiled refractory concentrate. Reactor Tanks 3 and 4 are being commissioned with the build up of inoculate.
The BIOX(R) Module 1, Reactor Tanks 5, 6 and 7 (smaller, secondary tanks), were expected to be commissioned in February 2007.
The BIOX(R) Module 1 coolers and blowers were commissioned in December 2006 and are operational.
The BIOX(R) Module 1 neutralisation tanks and counter-current decantation thickeners were expected to be commissioned at the end of January 2007 in time for the refractory ore feed in February 2007.
The new flotation circuit (not required until refractory ore is milled) was expected to be complete in February 2007. An expansion to the flotation circuit, which commenced in 2006, was expected to be commissioned in March 2007.
The new elution plant, (not required until all BIOX(R) tanks are commissioned), is progressing according to schedule.
The paddock dam transfer pumping-and-piping system to feed stockpiled refractory concentrate to the BIOX(R) plant is operational.
The stockpile build-up of refractory ore is advanced and about one-million tons have been placed on the stockpile.
Work on other areas which are not required until all BIOX(R) tanks are full is well progressed.

Participants
GRD Minproc and Group Five Projects.

Construction materials
650 t.

On budget and on time?
The project is on time and below budget.

Contact details for project information
Golden Star Resources, tel +1 303 830 9000 or fax +1 303 830 9094.