Cake size frequency distribution

By taking the difference between the two frequency (%/gm) columns, the size frequency distribution for the cake is obtained. This is shown in Table 7.3. 

Figure 4.4 depicts examples of weight frequency distributions for feed, cake and centrate. Note that the centrate and cake lines intersect at the cut point size, and at a frequency level half that of the feed at that size. Hence, there is a 50% split between cake and centrate at the cut point. 

Figure 6.12 is a graph, on log-probability scale, of feed and centrate particle size distributions for a run at 10 mVh. From this graph are calculated frequency distributions for feed and centrate solids, knowing the solids recovery for the run. These are plotted on the graph in Figure 6.13, together with the cake size distribution, which is the difference between the first two curves. Note that the cut point for the run is indicated, and recorded, for where the cake and centrate lines intersect. This is the size at which there is a 50 50 split of particles shared between cake and centrate. 

The three frequency distributions are plotted on the graph in Figure 6.13. The cut point is obtained as the particle size at which the cake and centrate distributions intersect. As, at this point, the frequencies for the two distributions are equal and total that for the feed, it follows that this frequency is half that in the feed, which is the definition of cut point. 

From the frequency distributions, the separational efficiency for each and any size may be obtained by taking the ratio of the frequencies, cake to feed, and multiplying by 100. This can be done for each feed rate tested. The efficiency plot for 10 m /h is shown in Figure 6.14. 

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