Magnetic drum

Media. Recovery Wet Magnetic Drums. In HMS recovery service, the particle size of the feed, particularly the magnetic portion, is quite fine so that dmm wear is not a serious problem. Maximum magnetic recovery is important and the highest magnetic purity and soHds content in the magnetic concentrate are desired. 

Dry magnetic drums can be designed to perform as lifting magnets or pulleys. Magnetic drum devices have stationary magnets pulley drums rotate. Other schematics of possible arrangements are presented in Fig. 19-44. 

FIG. 19-45 Wet-d rum-magnetic-separator arrangements, [a) Counterrota-tion-type wet magnetic drum separator. (Couttesif of Sola International, Inc.) (h) Concurrent-type wet magnetic double-drum separator, (c) Countercurrent-type wet magnetic double-drum separator. 

TABLE 19-21 Influence of Magnetic-Drum Diameter on Separation ... 

Cobalt zinc silicate blue phenacite, formula and DCMA number, 7 347t Co-base superalloys, 13 503, 525-527 composition of, 13 526 Cobbing services, magnetic drums used in, 15 445-446 Cobb test, 13 101 Cocaine, 2 74, 79, 80, 108 economic aspects, 2 108 Cocamide DEA, function as ingredient in cosmetics, 7 829t... 

Median particle diameter, 18 136 Media recovery wet magnetic drums, 15 443... 

Rotor bodies, in steam turbines, 23 231 Rotor electrostatic separators, 16 643-644 Rotor rotating converter, 16 151 Rotors, molecular, 17 59-61 Rotor spinning cotton yarn, 3 17 Rotor-stator devices, 10 127 Rotor-stator disperser, 3 701 Rotor-stator mills, 13 65 Rotor-stator mixers, 16 674-675 Rotosil process, 22 412 Roughages, as ruminant feeds, 10 863 Roughing, in mineral separation, 16 604 Roughing services, magnetic drums used in, 15 446... 

Media recovery magnetic drums are conventionally available in 762 or 914 mm diameter and in drum widths to 3.05 meters, usually in increments of 305 mm. The effective magnet width is about 150 mm less than the overall drum width. In some instances 1219 mm dia wet magnetic drums have been used, but the higher capacity of these units does not usually justify the higher costs involved. 

Feed Solids Content. A good HMS plant operation keeps the medium as free of fines as possible by effective screening of the heavy-media separation vessel feed. Reduced fines reduce viscosity problems in the medium and result in sharper separation of sink and float products. It also improves magnetic recovery on the magnetic drum separators and gives a cleaner magnetic concentrate. The use of cyclones in the HMS circuit, either as the heavy-media separation vessel or as a densifier for rinse or wash water, increases the solids content and must be evaluated in selecting the media recovery wet dmm separators for plants in which cyclones are used. 

Typically, ore bodies are relatively low in iron content. Iron minerals are finely divided in a gangue matrix. Wet grinding is usually required to liberate the iron minerals, although some beach sands may have liberated iron mineral values. Wet drum separators are limited to the treatment of material <10 mm. The magnetic drum separators applied are usually related to the grinding circuit required to liberate the iron mineral, and are typically designated by application as cobbers, roughers, or finishers. 

Cobbers. Magnetic drums used in cobbing services are designated to obtain maximum rejection of a nonmagnetic product and maximum recovery of the iron mineral. Typically, cobbers are applied on a rod mill discharge product. Because the objective is to obtain maximum capacity, these drums are 914 or 1219 mm in diameter and incorporate wear covers on the drum shells to take the wear introduced by the relatively coarse feed size. 

Desired Magnetic Recovery. In ore concentration, maximum recovery is desired at all times. Rejection of middling particles, although sometimes desired, is difficult to accomplish on wet magnetic drum separators. 

Magnetic drum selection of alternating polarity drum separators is based on the capacity to be handled and the particle feed size. Recommended capacity and drum-type selections for permanent magnets are as follows, where 0 indicates fines ... 

The larger model, the G2, with 30 operations per second and a magnetic drum storage of 2048 words at (50 + 1) bits fixed point, went into operation in the fall of 1954 in Gottingen, two years before the main German competitor PERM in Miinchen. 

The most common magnetic separators used in solid waste separation and recycling are head pulley magnets, magnetic drums, and suspended belt magnets. 

Magnetic Drum. A magnetic drum is usually composed of a permanent magnet, a compact piece, or set of axially oriented bars of alternahve polarity, mounted... 

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