Plutonic east

The Plutonic East underground gold mine in the Northern Murchison Region of Western Australia is owned by giant Canadian gold mining and exploration company Barrick Gold Corporation. It is located 180 kilometres from Meekatharra and 13 kilometres off the Great Northern Highway.

Barrick Find Gold Price Challenging For Plutonic East Survival
Although, at the end of 2012, the Plutonic Mine had proven and probable mineral reserves containing 206,000 ounces of gold, it cost Barrick $1,134 an ounce with adjusted operating costs of $971 an ounce, in producing 60,000 ounces in first half of 2013. This result caused the company to consider optimising the gold mining at the mine to improve its cash flow or otherwise look at divesting itself of its Plutonic asset.

Plutonic East Gold Deposit Discovered in 1988
The Plutonic gold deposit was discovered by Great Central Mines in 1988 and sold to Plutonic Resources in 1989. Homestake Mining Company acquired Plutonic in 1998. It was acquired by Barrick Gold near the end of 2001. The mine has been worked as an open cut and underground mining operation. Open cut mining commenced at the Plutonic mine site in 1990 with the underground operation beginning in early 1995. Major expansion work was carried out in the underground mine between 1998 and 2000 where the mining method used is room and pillar incorporating long hole open stoping technology.

Plutonic Mine has two Gold Processing Plants
There are two gold processing plants at the Plutonic East Mine, plant one and plant two. Processing plant one was constructed to service the underground mine and plant two serviced the open pit mining operations. The underground mine is the primary source of gold mining being carried out at the Plutonic Project although minor mining has been continued at some of the smaller pits. Gold processing plant one is able to handle 1.8 million tonnes a year of sulphide ore from the underground operation. Plant two is designed to treat up to 1.2 million tonnes of oxide ore mined from the open pits.

In processing plant one, run of mine (ROM) ore is crushed to a very fine degree with the use of jaw crushers. The crushed ore is then transferred to the SAG mill that puts it through two ball mills operating in parallel that grind it finer. The ground ore is transferred to a leach tank where it is subjected to cyanide leaching that ends up producing a pregnant solution. This pregnant solution is transferred to an adsorption tank where the gold is separated from the solution. The resulting precipitate is what is fed into a refinery, or smelter, to produce pure gold dore bars for export. During the process the adsorption tank solution is transferred to the tails thicker for further recovery. Gold processing plant two works in much the same way as does plant one except that it uses a single stage grinding and crushing of the oxide ore.

In November 2009 the International Cyanide Management Institute (ICMI) accredited the Plutonic East mine as being a fully compliant gold mine under the auspices if the International Cyanide Management Code (ICMC).
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