Pr oc es sing The Campbell Mill uses conventional crushing and grinding which is followed by gravity concentration to recover free milling gold Refractory gold is recovered by fotation followed by pressure oxidation neutralisation and CIL Evolution plans to increase the capacity of the Campbell Mill to 1Mtpa by 2023 Evolution s planned operational improvements include Install and commission Acacia reactor to improve gold recovery Optimise process fowsheet and strategic blending of mill feed Geology The Campbell Red Lake gold deposit is location in the Red Lake greenstone belt with a total of approximately 840 tonnes of gold past production and reserves at an average grade of 21gt gold It is one of the largest and richest Archean gold deposits in Canada Gold mineralisation is mainly associated with silicifcation and arsenopyrite that replace carbonate veins breccias and wallrock selvages The carbonate veins and breccias which are composed of ankerite quartz and characterised by crustiformcockade textures were formed before andor in the early stage of penetrative ductile deformation whereas silicifcation arsenopyrite replacement and gold mineralisation were coeval with deformation