Macraes Gold Project - Creating Value with Metallurgy

Since its inception in 1990, improved metallurgical processing technologies, coupled with mine planning enhancements and improved geological knowledge, have sequentially enabled better efficiencies and economies of scale at the Macraes Gold Project. Over a period of 11 years, processing enhancements have been achieved by: +        increasing mill throughput, from one million tonnes per year, to current throughput of 3.9 million tonnes per year; +        improving recovery rates, from 70 % to approx 84 %; and +        performance enhancement through innovation, eg the use of kerosene to combat ClL pregrobbing. Future processing improvements have been identified in optimising the ore feed and processing flowsheet. The introduction of the autoclave has transformed the process flow form a traditional 'mill headgrade and tonnes milled' operation, to a 'sulphur/gold ratio and sulphur tonnes oxidised' operation.