The recommissioned Boddington gold mine was officially opened on February 3, by Western Australian Premier Colin Barnett and President of Newmont Mining Corp. Richard O’Brien.
Boddington is a large, open-pit mine about 130 km southeast of Perth. It is located within the Saddleback Greenstone Belt, a fault bonded sliver of achaean volcanic and shallow level intrusive rocks, surrounded by granitic and gneissic rocks. It is 100% owned and operated by Newmont Mining Corporation.
The premier said the A$3.5-billion recommissioned mine heralded a new era of gold mining in Western Australia. He said the mine is expected to inject A$770 million into the Western Australian economy every year for the next 20 years.
Western Australian mines and petroleum minister Norman Moore said recent technological advances and the strong gold price were the drivers behind the reopening of the gold mine.
The Boddington mine originally operated from 1987 to 2001. Mining operations ceased after the known near-surface oxide ore resource had been processed. About 692,000 oz were produced.
A bedrock resource of almost 20 million ounces was identified and expansion of the facility to allow mining and processing of basement rock was approved in 2002. Construction of the expansion began in May 2006.
Boddington startup commenced in July 2009, with first concentrate produced in September 2009. The startup includes a 12-month ramp-up schedule. In October 2009, Boddington gold mine changed its name to Newmont Boddington Gold. In November 2009 the mine successfully reached commercial production.
The mine will surpass the Kalgoorlie-Boulder Super Pit in terms of size and production in coming years, and will become Australia’s largest gold mine. The Super Pit is owned by Kalgoorlie Consoldatetd Gold Mines Pty Ltd, a company owned 50:50 by Barrick Gold and Newmont Mining. It is about 3.5 km long, 1.5 km wide and 360 m deep.
Boddington will produce about 1 million oz of gold annually in the first five years before averaging about 850,000 oz/y during its 20-year lifespan. It will lift the state’s gold production 20%. It will also produce 30,000 mt of copper for the first five years.
Intierra Resource Intelligence, a company providing business intelligence for the minerals processing sector, said Boddington has a proven-probable reserve of 793.67 million mt grading 0.786 g/mt gold and 0.11% copper, and measured to inferred resources of 918.9 million mt at 0.52 g/t gold and 0.087% copper.
The mine comprises two large open pits with hard and abrasive rock. The pits are 4 km long, 1 km wide and 700 m deep. The mine’s conveyors are of a total length of 5.3 km, and overland conveyor length is 2.2 km. The mine features two 60 x 110 primary crushers, four high pressure grinding rolls, five MP 1000 secondary crushers, four 26 x 44-ft ball mills with the largest twin pinion drives produced to date, and more than 30 Cat 793 mine haul trucks.
The ore is crushed in a three-stage process and then ground in ball mills. The slurry then goes through a flotation process where the material is separated into two streams. One stream is filtered to provide a concentrate containing all the copper and 50% of the gold. The concentrate is shipped to smelters working with Newmont under contract. The second stream goes through a carbon-in-leach extraction process. Gold recovered in the CIL circuit represents about 50% of total gold production. Ingots are transported to the refinery located near Perth international airport.
The copper concentrate is transported by truck about 160 km from Boddington to the port at Bunbury.