The Boddington Gold Mine (BGM), Australia’s largest gold-producing mine, is located 130km south-east of Perth in Western Australia.

The $2.4bn project was initially a three-way joint venture between Newmont Mining, AngloGold Ashanti and Newcrest Mining. In 2006, Newmont bought Newcrest’s 22.22% share, bringing its interest to 66.67% and ending any Australian ownership.

AngloGold owned the remaining 33.33%. In June 2009, Newmont became the sole owner of the mine by acquiring the 33.3% interest of AngloGold. The original, mainly oxide open-pit mine was closed at the end of 2001.

The project has an attributable capital budget ranging between A$0.8bn and A$0.9bn. On 23 July 2009, the project, including the construction of the treatment plant, was completed. Production began in the third quarter of 2009. The first gold and copper concentrate was produced in August 2009.

Approximately 100,000t of ore was processed by mid-August. Gold production began on 30 September 2009. By 19 November 2009, the mine achieved commercial production. The mine was officially inaugurated in February 2010. The project had an attributable capital budget of between A$0.8bn and A$0.9bn. It employs 900 workers. The attributable life-of-mine gold production is expected to be greater than 5.7Moz.

Boddington Gold Mine expansion details

In May 2012, Newmont decided to seek to expand the mine life by combining the north and south Wandoo open pits. It also plans to expand the waste rock facility to two billion metric tons.

Newmont and Anglo had focused their exploration activities on the poorly explored areas of the greenstone belt outside the already identified Boddington Expansion resource. The exploration strategy was to identify the resource potential of the remainder of the greenstone belt, with the emphasis on high-grade lode-type deposits.

The environmental authorities approved the life of mine extension project in August 2013. The project has the potential to extend the mine life to 2041. The expansion project includes the development of new RDA, expansion of waste rock dumps (WRDs), the development of new water storage dams and associated infrastructure and associated modification in the existing residue disposal area (RDA), the deepening and widening of pits, and additional stockpiles.

The construction of additional drainage and buttressing along Saddle Dams 3, 4, 5, 7, 8 and 9 of the F1 RDA for the project was approved in February 2019.

Geology and reserves at the Boddington Gold mine

The BGM is located within the Saddleback greenstone belt (SGB), a fault-bounded sliver of Archaean volcanic and shallow level intrusive rocks, surrounded by granitic and gneissic rocks.

The SGB produced more than 6Moz of gold and is a highly prospective exploration area for further gold mineralisation in both large tonnage stock-work gold resources and high-grade lode-type gold resources.

By the end of 2018, proven and probable ore reserves at Boddington were 12.35Moz of gold and 170 million pounds (Mlb) of copper.

Mining and production at Boddington mine

Built on the footprint of the original BGM, the operation involves open-cut mining from two large pits and is expected to produce an average 850,000oz of gold and 30,000t of copper a year for more than 20 years.

Production commenced in 2009 under the management of the Boddington Gold Mine Management Company, a 100% Newmont-owned company.

Average attributable gold production in the first five years will be 1Moz a year, while on an average life-of-mine basis, attributable production is estimated to be between 250,000oz and 270,000oz a year.

Copper production, which is sold as concentrate, is expected to be 30,000tpa. In 2009, approximately 103,300oz of gold and 9Mlb of copper were sold from the Boddington mine. The mine produced 709,000oz of gold and 77Mlb of copper in 2018.

Processing at Western Australia’s copper and gold deposit

Ore containing copper and gold is crushed to a coarse size before the ore is sent to the treatment plant via a conveyor. At the treatment plant, the ore is crushed further and ground finely to slurry. The ore is initially processed by flotation, which produces copper / gold concentrate with 18% copper.

Fine liberated gold is recovered by processing flotation concentrates through a gravity circuit before it is dewatered and stored. It is then ship-loaded for delivery to the smelters. The residual gold content found in the flotation tailings is recovered through a carbon-in-leach circuit.

The processing equipment used at the mine includes two 60X113 primary crushers, five MP 1000 secondary crushers, four high-pressure grinding rolls and four ball mills.

The wastewater treatment plant at the mine provides up to 0.5 megalitres each day.

Contractors involved with Boddington mine

In January 2007, Outokumpu Technology was awarded a contract to supply complete thickening circuit for the mine.

In February 2011, Boltstress Ultrasonics Service completed ultrasonic monitoring and torque tightening of the structural fasteners at the ball mills in the mine.

In July 2011, Newmont selected ApplyIT’s IntelliPERMIT software, which is a computerised permit-to-work system. The system ensures tightening and streamlining the safety procedures at the mine.

In August 2011, Macmahon was awarded a contract to provide mining and ore re-handling services.

Design, construction and commissioning of electrical and instrumentation services for the wastewater treatment plant at the mine were provided by Hueppauff Electrical. The equipment for the plant was provided by Weir Services Australia.

Mageba supplied ten type KE-1, Reston-spherical bearings, equipped with ROBO-SLIDE, for the project. Knight Pièsold is also involved in the project.