There’s life in the old mine yet according to Carbine Resources, which plans to remediate a 130 year-old mine and continue to extract copper and gold.
The Mount Morgan mine, once known as the largest gold mine in the world, will soon be reopened by Carbine thanks to a deal with the Queensland government to take over the site’s existing lime dosing water treatment plant.
Management of the water treatment plant will allow Carbine Resources to target improvements to both the volume and quality of treated water entering the nearby Dee River.
This will reduce the level of water in the pit while improving the environmental health of local waterways.
The proposed operation at Mount Morgan will also provide and economic pathway for remediation of environmental legacy issues caused by acid mine drainage from historical operations.
Carbine Resources has been nominated in the 2015 Prospect Awards for Innovation in Mining, for their plan to use ion exchange technology to extract copper from leaching solutions, rather than the typical cyanide leaching required to liberate gold in the presence of excess soluble copper.
Processing tailings by this method will result in lower operating costs and improve gold recovery compared with historical operational performance.
The process will also assist with site remediation by removing acid-forming pyrite from tailings at the site.
Queensland Resources Council chief executive Michael Roche welcomed the announcement of the new agreement with state government.
‘This announcement demonstrates industry’s improving knowledge base which has made treatment of the tailings water locally a reality,” he said.
“Critically, this announcement will have local and regional environmental benefits to the overall health of the local waterways with treated water released into the local Dee River.
The pre-feasibility study for Mount Morgan has defined an eight year mine life at a processing capacity of 1Mtpa, producing 31,200 ounces of gold per year at an all-in sustaining costs of $US243 per ounce.
The mining operations are also projected to deliver 3,200tpa of copper sulphate and 211,000tpa of high grade pyrite, which is used in the manufacture of sulphuric acid, a principal ingredient in the production of fertiliser.
Roche said Carbine had added to the viability of the project by signing a binding off-take agreement for the sale of pyrite from Mount Morgan to global industrial mineral distributor Talana Limited.
“This is proof that there is still value in abandoned and disused mine sites and demonstration that even an asset as old as Mount Morgan still has a residual value, which Carbine is now harnessing,” Roche said.
Carbine Resources has already won the 2015 Austmine Award for Innovation in Mining for their efforts to date.