Newcrest Mining Limited

Located in Western Australia, 450 km inland from Port Hedland, lies the Telfer gold mine. Owned by Newcrest Mining Limited, the mine was at one time the most productive in Australia, producing 6 million ounces of gold over a span of 25 years. However, increasing amounts of copper in the Telfer ore forced the mine to suspend operations in the year 2000.

The copper, which was leached out by cyanide during the gold treatment process, had made operations at Telfer uneconomical. Yet feasibility studies indicated that a rich body of ore still existed underground. In 2002, the Newcrest Board thus approved a plan to expand the plant’s capacity, creating a massive, high-volume operation that would achieve economies of scale.


Sizeable needs

The Board’s feasibility studies indicated that the Telfer mine would have to crush and mill 17-20 million tons of ore per year in order to justify operations. A conventional crushing and grinding circuit in two production trains was proposed, incorporating both underground work and an open pit mine.


The plan called for one primary gyratory crusher to be installed underground, while two were to be installed above ground for use in the pit. After crushing, the ore would enter a production train and pass through one of two semi-autogenous (SAG) mills, then through one of two ball mills in circuit with the SAGs. As it turned out, Metso was the only supplier who could provide this equipment in a size sufficient for the desired capacity.


Reputation and respect

While equipment size was a major issue, however, it was not the only reason Metso received the contract in October 2002. Because of the huge scale of the new operations, Newcrest was anxious to avoid major breakdowns and failures. The Metso reputation for durability was appealing, as was the fact that Metso had supplied other plants of similar size.

In addition, Metso’s service played a pivotal role. Metso had done good work at Newcrest’s Cadia mine, where a team led by Keith Hill had installed the world’s largest SAG mill in 1996. Having been impressed by his experience and his straightforward working style, Newcrest requested Hill for the commissioning of the Telfer equipment as well.


A promising start

The Metso team had a challenging schedule for commissioning the new equipment, which included spending Christmas 2004 at the remote Telfer site. The tough work in the field, however, allowed Newcrest to commence commercial operation of the pit mine in February 2005.


Reaching the throughput performance criteria in just two to three weeks, the startup ranks among the world’s best.

The increased scale of the Telfer plant has made mining there highly economical. Cash flow is good, and the copper that was once a problem is now produced as a concentrate and sold to complement gold revenue. Thus, with the new Metso equipment running steadily and reliably, Newcrest officials are looking with optimism at Telfer’s projected 25-year run.