Scope of Work
GR Engineering was appointed by Avoca Resources Limited to undertake the engineering, design, procurement, construction and commissioning for the new process plant facilities at Higginsville Treatment Plant. The project required the development of a gold concentrator to treat 1.0 Mt per year of underground ore.
The Higginsville Treatment Plant is designed for a nominal 123 tph milling rate, run of mine material is fed to the crushing plant at a design rate of 225 tph with crushed ore storage capacity installed to provide a break between crushing and milling operations. The gold concentrator is designed as a conventional carbon in leach (CIL) arrangement.
Underground ore is crushed to nominally minus 9 mm in a three stage hard rock crushing plant and then slurried and milled to nominally minus 0.075 mm (75 μm) in a single stage 3 MW ball mill in a closed circuit with hydrocylones. The comminution circuit includes a gravity gold circuit consisting of a gravity concentrator and an intensive cyanidation circuit. The balance of gold recovery is obtained from a seven tank CIL circuit, four tonne pressure Zadra elution circuit and electrowinning systems.
GRES commenced the EPC design and construction of the gold treatment plant in May 2007, with Practical Completion achieved 7 June 2008.
With practical completion achieved on schedule and within budget, the Higginsville design and construction project has been successfully completed with first ore going through the mill on 16 June 2008.
The Higginsville Treatment Plant commenced dry commissioning of the process facilities during the month of May, reaching this milestone maintains the focus of completing the facilities on schedule for handover to Avoca.
The final shipment for the Higginsville ball mill was delivered in April, completing the critical equipment deliveries and setting the site works up for on-schedule commissioning in June 2008.
Project management representatives visited Citic Heavy Machinery Company Ltd in China in January to view the fabrication progress of the ball mill, scheduled to leave China in February with the first shipment planned to arrive at Higginsville Treatment Plant in early March
Design and construction of the Higginsville Treatment Plant, located approximately 50 km north of Norseman in the Eastern Goldfields region of Western Australia, has reached the half way mark