OceanaGold’s Haile gold mine in South Carolina, USA, is about to take possession of an M10,000 IsaMill™ from Glencore Technology for ultrafine grinding duties. OceanaGold’s Chief Development Officer, Mark Cadzow, said the new IsaMill will re-grind gold-bearing concentrate from 42 microns to below 13 microns, which will improve leach recovery of the flotation concentrate, at considerably lower maintenance and grinding media costs than previously gained.

“The installation of the Glencore Technology M10,000, 3,000KW IsaMill at Haile will assist in maximising gold recovery at our operation”, he said. “We’ve already proven this technology, having utilised a smaller M1,000 IsaMill at our Macraes mine for many years with excellent results.” Glencore Technology’s IsaMill Technology Manager said the new mill is enroute to South Carolina and installation by his team is set for January 2019.

“This is a great application of the IsaMill and a highly valued repeat customer. Haile’s IsaMill will process up to 55 t/h of Pyritic feed. It’s a hard ore so the mill is going to get some good use”, he said. Although Haile Gold’s recoveries have consistently averaged in the low 80% range, the grind size achieved by other equipment has only been 19 microns. The ability to regrind to 13 microns should increase recoveries and deliver additional value from OceanaGold’s asset.

Glencore Technology has designed the layout and engineering of the complete IsaMill plant for the installation to improve maintainability and operability. Design includes mill, feed and discharge hoppers and pumps, cyclone cluster, media dewatering and media handling. It also includes all structural, piping and electrical, instrumentation and controls engineering.

Glencore Technology were engaged by OceanaGold for the supply of engineering services for the IsaMill plant while Ausenco were engaged for integration with the existing operation. The entire plant with all equipment and feed and media handling is a 25 by 13 metre footprint. The IsaMill plant will play a key role in Haile Gold’s plans to increase plant throughput rates toward an 3.5 to 4 Mt per year as OceanaGold chases organic growth and increases production by 20%.