Classifiers rake type

Rake and Spiral Classifiers Rake-type classifiers such as the Dorrf classifier and spiral types such as the Akinsj have been the workhorses for general-classification problems for half a century, and their names describe the mechanisms installed in sloping-bottom tanks. See Fig. 19-24. Mechanically the devices are powerfully built, and functionally they are versatile and flexible. They were tfie first classifiers used successfully for closed-circuit grinding. Separations as fine as 325 mesh can be accomplished at reduced tonnage rates. 

Sodium sihcate (41°Bh, 1 3.22 ratio Na20 Si02) is added in the milling operation to disperse the slime, mosdy kaolin. Dispersion also aids the grinding process. The rod mill serves to grind the ore to 0.833 mm (—20 mesh) or to the point where mica, quart2, feldspar, and iron minerals are Hberated. Cyclones, or rake, hydrauhc, or other types of classifiers, are used after grinding to produce coarse and fine mica fractions that are treated separately. 

Organosilicone surfactants can be classified according to the position of the lyophilic moiety with respect to the Si-O-Si polymer. The abbreviations M, D, T and Q, referring to the number of oxygen atoms bonded to the silicon, are used to define the silicone portion as shown in Table 2.8.2. Insertion of the lyophilic moiety (A) into the silicone polymer itself leads to monofunctional, i.e. M(D A)M, and polyfunctional linear, i.e. MID A D M, type surfactants. Polyfunctional linear versions are also described as rake, comb- or graft-copolymers. Substitution at the ends of the silicone polymer yields surfactants... 

Tsuchiya and Imamura [1] calculated a lot of n-butenes reaction profiles as a function of X (=kic/kit) and y (=kct/ku) on the basis of the Wei-Prater method [3]. In view of the acid-base catalysts, they classified these profiles into four types (1) cis-convex, (2) rake, (3) trans-convex and (4) tree. The reaction profiles for base catalysts are of the cis-convex type. Reaction profiles of the trans-convex type are obtained by acid catalysts. 

Continuous wet classifiers, of the rake and spiral type, and hydroclones (hydrocyclones) can also produce concentrated slurries, but the overflow liquid is not clear, containing the smaller particles. A separation of particles by size and density occurs. Hydroclones are inexpensive, typically 6 in. in diameter or less, and a single unit can handle only low flow rates. For high flow rates, parallel units are employed in a multiclone. Table 16.32 contains f.o.b. purchase costs for wet classifiers and hydroclones. The size factor is the solids flow rate for classifiers and the liquid flow rate for hydroclones. 

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