A typical flowsheet for a crushing plant producing ball mill feed is shown in Figure 6.31 (Motz, 1978). The circuit is typical of current prac- tice in that the secondary product is screened and conveyed to a storage bin, rather than feeding the tertiary crushers directly. The intermediate bins allow good mixing of the secondary screen
oversize with the circulating load, and regulation of the tertiary crusher feed, providing more efficient crushing. The circuit is also more readily adaptable to automatic feed control to maintain maximum power utilisation (Mollick, 1980). In some cases, the crushing circuit is designed not only to produce mill feed, but also to provide media for autogenous grinding. Figure 6.32 shows the flowsheet for the crushing circuit at Pyhasalmi