Screen Grizzlies

Grizzly Screens These consist of a set of parallel bars held apart by spacers at some predetermined opening. Bars are frequently made of manganese steel to reduce wear. A grizzly is widely used before a primaiy crusher in rock- or ore-crushing plants to remove the fines before the ore or rock enters the crusher. It can be a stationaiy set of bars or a vibrating screen. 

The simplest industrial screening equipment are stationary screens, over which the material to be screened flows. Typical of this type are Grizzly screens, which consist of rows of equally spaced parallel bars, and which are used to scalp off over-sized rocks in the feed to crushers. 

The use of grizzly screens to produce scalpings rich in unwanted clay has already been mentioned (section 5.5.2.3). The decision whether to wash scalpings depends on site specific factors, such as the quantity of scalpings, the availability of water, whether the washings can be processed in slurry ponds, and the demand for washed and un-washed scalpings. 

Fig. 5. Schematic diagrams of screens (a) vibrating grizzly, (b) double-deck vibrating screen, and (c) a rotating probabiUty screen (2). A schematic...

The screening surface may consist of woven-wire, silk, or plastic cloth, perforated or punched plate, grizzly bars, or wedge wire sections. 

VvrA P Hiah-sp c Nov V1 br01ing screens 0, derrn.p Ro(3-oeck screen grizzly ... 

High speed vibrating screens. . , Rod Rod - deck screen grizzly ... 

Screen-section Materials.—The materials most commonly used for making screen sections are (1) Punched, drilled and cast plate with cored holes (2) grizzly bars, some of the more common of the weights and dimensions of which are shown in Fig. 17... 

Deep bed or granular batch, for 0.01 to 50 J,m (see filter. Section 16.11.5.13). Fixed bar screen batch, grizzly (the filter cloth is made of rods and bars) removal of very coarse material of diameter >2 to 5 cm low concentration of solids <15 mg/L bars at 30 to 60° to the horizontal that can be cleaned manually or automatically. Microscreen (rotary drum or disk). Batch, removal of participles of diameter >20 jm 20 mg/L solids feed concentration. 

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