SAG mill feed size distribution manipulation and optimization

Question: In our Gold Plant we have 2 SAG (tubular 24x16 feet) mills operating in parrallel in closed circuit with hydrocylones, the mill feed size is 170mm and flactuates up to 200mm (crusher gap). In an initiative to increase throughput one of the option is to have a pre crusher to reduce feed size distribution and have a controlled feed rate. Any suggestions on optimizing such circuit?.

Reply: Not sure about your circuit configuration,but you need to optimise your whole circuit, possibly including crusher, SAG and Ball Mills. A single SAG mill has to take into account both throughput and size distribution. You cannot sacrifice one for another one. For circuit optimisation, you have several options - approaching mill vendors or specialised simulation service providers, assuming you have relevant ore properties available.