Classification, equipment

Equipment Classification Equipment can be broadly classified into the following categories, generally in order of increasing complexity of internal construction. Those most generally used are ... 

Electrical work - certain classifications Equipment removal, e.g. to workshop Work on roof/at heights... 

There is a clear need for other size classifiers which combine a high separation efficiency with flexibility and compactness. Hydrocyclones have a small volume, are simple in operation and are standard size classification equipment, for example in closed circuit grinding applications. The recent development of the flat-bottom hydrocyclone, which permits classification in the coarse size range, creates an additional motive to study the use of hydrocyclones for Crystal Size Distribution (CSD) control. Furthermore, throttling of a flat botom hydrocyclone does not necessarily provoke blockage but allows continuous control of its cut size when a controlled throttling valve is used. There is a clear incentive for its use in this application since it may provide an additional process input. 

Estimate of Installed Facility Cost Prescreening and classification equipment 3.6 3.6 3.6... 

To use natural minerals it is necessary to grind them down to a desired particle size distribution. Grinding can be performed with the minerals dry or slurried in liquid. In most laboratories, this process is performed in a batch jar mill while on an industrial scale, continuous comminution equipment is used in conjunction with size classification equipment to recycle the coarse material. Figure 4.1 shows a typical comminution circuit with classification and recycle steps, as well as separation of the mineral from the conve3ring fluid. 

Dry classification equipment uses a gas stream to convey the solids. The gas used most oflen is air, and for that reason the term air classifiers is often used to describe this type of equipment (see Fig. 4.10). Air classifiers evolved from two sources, the original simple expansion chamber and the Mumford and Moodie separator, patented in 1885. 

FIGURE 4.10 Air classification equipment (a) cyclone, (b) expansion chamber, (c) modern complex air classifier, and (d) classifier based on particle inertia. 

Wet classification is performed by filtration, settling, centrifugation, Sind hydrocyclones. When operated in conjunction with grinding equipment, the wet classification equipment must operate continuously and give a pumpable fluid. This is often accomplished in practice with hydrocyclones because the other methods are unsuitable (e.g., settlers and centrifuges are used for dilute suspensions, filters and screens produce a nonpumpable cake.)... 

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