A crushing circuit consists of a primary gyratory crusher located near the pit. This is in open circuit, with the product being conveyed to the processing plant. In the plant this material is then fed onto a screen, with the underflow acting as the feed for the milling circuit. The overflow from the screen (oversized material) then acts as the feed for a secondary cone crusher, with the product from this crusher being fed back onto the screen. a) Draw the circuit, labelling items. (3) The total solids feed rate to the circuit is 1000 t/hr. Consider two particle size fractions, namely particles above and below 1cm. In the feed to the circuit only 10% of the material is below 1cm in size. The gyratory crusher will break 40% of the material above 1cm to below 1cm in size, while the cone crusher will break 50% of this material to below 1cm. The screen has a partition number of 0.8 for the larger particles and a partition number of 0.25 for the finer particles. b) Carry out a mass balance over the circuit calculating the mass flowrates of each of the components in each of the streams. What is the percentage passing 1cm in the mill circuit feed?