The layout of crushing plants and ancillary equipment and structures

In mining operations, the layout of crushing plants and ancillary equipment and structures is a crucial factor in meeting production requirements while keeping capital and operational costs to a minimum. This stone addresses the critical design parameters as well as the consideration of ore characteristics, geographical location, climatic conditions, expected operational life, expansion potential, safety, environment, and operability and maintainability.

The fundamental goal for the design of a crushing plant is an installation that meets the required production requirements, operates at competitive cost, complies with today's tough environmental regulations, and can be built at a reasonable price despite the rising costs of equipment, energy and construction labor. The following industry trends must be taken into account:
1 Equipment suppliers are offering ever-larger primary crushers, with 1,800 mm (72 in) gyratories expected soon, as well as secondary and tertiary machines of up to 3,000 mm (120 in).
2 Rising energy costs are causing owners to increase the integration of mine and mill design, so that they can identify ways of reducing overall electrical power consumption.
3 Electronic control of crusher discharge opening and feed rate. With adjustment of a crusher's discharge opening, as the production continues through an on-line coarse size analysis of the crushed product (digital image analyses).
4 More attention is being paid to the impact on crushing circuit design caused by variations in ore characteristics, size distribution, moisture content, ore grade and climatic conditions.
5 Operators have always dreamed of reducing the need for crushing equipment; when SAG mills were first introduced, it was hoped that they would eliminate secondary and tertiary circuits. As it turned out, designers are now adding secondary or pebble crushers to SAG circuits, on both greenfield and retrofit projects, to increase feed rate to the SAG mill. In other words, crushing plants, from primary to quaternary circuits, are here to stay.

There are three main steps in designing a good crushing plant: process design, equipment selection, and layout. The first two are dictated by production requirements and design parameters, but the layout can reflect the input, preferences and operational experience of a number of parties. These can include the owner's engineering staff, safety personnel, operations and maintenance personnel, equipment manufacturers, and the engineering consultant. Ideally, the consultant combines his knowledge and experience with an understanding of all parties' needs, to provide a balanced, workable, safe and economic plant design.