Newmont Mining operates the Yanacocha mine in Perú and the gold milling section of the property includes a Sulfidisation-Acidification-Recycle-Thickening (SART) plant to remove copper from pregnant leach solution. Since its commissioning in 2008, the plant has been intermittently operated as needed to remove copper upstream of a carbon adsorption circuit. However, starting in 2015 Newmont expects the plant to operate on a more continuous basis in response to higher copper ores that will be processed in the gold mill. In anticipation of this, Newmont conducted a campaign in May 2014 with stockpiled high-copper ore to evaluate performance of the SART plant with elevated levels of copper in feed solution.

A paper at this week’s SME Annual Conference in Denver presented results from the campaign that demonstrated the SART plant is capable of efficiently treating high-copper leach solution. During the campaign, leach solution copper levels ranged from about 100 to 700 mg/litre, and copper removals ranging from about 56% to +99% were achieved. The median copper removal efficiency observed during the campaign was about 94%. The primary plant modification determined necessary following the campaign was the need to improve consistency with sulphide dosing.