Consider a grinding circuit, consisting of a rod mill in open circuit and a ball mill in closed circuit with a hydrocyclone, as in Figure 1. (a) Imagine that, as part of a survey of the above circuit, samples were taken of the rod mill and ball mill discharges and of the cyclone underflow and overflow, and that sieve analyses of composite samples of these products gave the following results: Calculate the circulating load over the ball mill / cyclone circuit. [2\%] (b) If the feed rate to the rod mill is 95 tph (dry weight), what is the size distribution in the cyclone feed, based upon the above data? [6\%] (c) What is the feed rate to the ball mill, based upon your answer to question (b)? [2\%] (d) From these data, calculate the recoveries to the cyclone underflow for the different size fractions and plot these against particle size on the graph paper. [6\%] (e) What is the separating size in this cyclone operation, based upon these data? [2\%] (f) What is the 'imperfection' in this cyclone operation, based upon these data? [2\%]