Problem 2 A two stage grinding circuit using a rod mill in open circuit with a ball mill in closed circuit with a rake classifier is used to grind 40 tons per hour of ore (sp. gr. 3.0). Dilution Water Feed Rod Mill Overflow (Fines) Rake Classifier Sands (Coarse) Ball Mill Sump Pump The circuit is sampled and analyzed for percent -100 microns material and percent solids. Circuit sampling results % -100 microns Stream Circuit (Rod mill) Feed Rod Mill Discharge Classifier Sands (Ball Mill Feed) Classifier Overflow Ball Mill Discharge 5 20 20 75 47.5 % solids by wt 80 80 75 33.3 75 Using the above data carry out a material balance and calculate: (a) the tons/hr of dilution water added to the rake classifier (b) the percent circulating load in the ball mill circuit (c) the flow rates and specific gravities of all streams and illustrate the material balance of the whole circuit