The majority of published material regarding the operation of
crushing machinery is concerned with simulation of performance
rather than design of equipment. The reason underlying the bias
in published material relates to why research is carried out and
who undertakes the research. Two distinct types of research can
be identified: 1. Internal research by crusher manufacturers - generally
related to mechanical design, value engineering and to the
commercial realities attached to sales demands. Any work
on basic crusher geometry or rock/machine interaction is of
a sensitive nature and rarely enters the public domain. 2. Academic research - mostly confined to modelling of
crusher performance and simulation. This is not because of
any bias, but crusher design requires access to
manufacturers data or at least an in-depth understanding of
crusher design, which is rarely available. The crushing of rock is a complicated problem. It involves
three aspects; the machine geometry, the material composition
(type of rock/feed size distribution) and the machine/rock
interaction. The machine geometry is often ignored in empirical
mineral processing simulations, while the response of different
feed materials is only nominally addressed in machine
specifications provided by manufacturers. The manner by which
the machine produces a stress field and causes different types of
breakage for different rocks (or the machine/rock interaction) is
sadly neglected by both groups. All three aspects must be
considered collectively to successfully understand and model the
entire crushing process. 1. Centre for Mining Technology and Equipment, Julius Kruttschnitt Mineral Research Centre, University of
Queensland, Isles Road, Indooroopilly 4068 Qld. The importance of crushing is often underestimated. In mining
and mineral processing the invisibility of the crushing process is
understandable as it merely provides a coarse reduction stage
prior to the intricacies of mineral extraction. However in the
quarrying industry crushing and screening basically provide the
finished product. A brief overview of the quarrying industry
shows the importance of crushing. Figure 1 gives production
figures for most of the western European countries, Australia and
the USA.