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Title: Technology of cleaning fine coal in dense-medium cyclones

Journal Article · · Coke Chem. USSR (Engl. Transl.); (United States)
OSTI ID:5520970

Due to the fact that coal fines are becoming increasinglyly difficult to clean and higher in sulfur, it is becoming increasingly necessary to use an efficient technology for cleaning them. In recent years for practical cleaning of coal of below 0.5 mm size grade there has been extensive use of flotation machines, hydrocyclones, Deister concentration tables and certain other types of equipment. They all have certain deficiencies, however. In particular, oxidized coal is not cleaned efficiently in flotation machines; high sulfur coal requires very low separation densities, for example 1300 kg/m/sup 3/, etc. The experience of the firm Stamikarbon in the field of industrial cleaning with dense-medium cyclones, extensive investigations and the operation of washeries permit us to state that under certain conditions it is possible to clean coal of below 1.0 mm size grade in high-head, dense-medium cyclones of 250 mm diameter. The working medium is separated from the cleaning products by means of an original combination of magnetic separators and arched classifiers with narrow slots. The use of this equipment permits classification of material at a particle size of 0.075 mm without clogging the screen slots. The final products are efficiently processed on classifiers of a new type. Dense-medium cyclone complexes are the most expensive types of equipment designed for cleaning of below 0.5 mm coal. However, a number of cases have been noted when it is economically feasible to use dense-medium cyclones, for example in separation at a low density, cleaning coal with a high content of fractions of density close to the separation density, and processing of oxidized coal. Dense-medium cyclones may be used successfully to clean coal to a size grade of 0.5 to 0.1 mm. The selection of the most economical process is determined by the type and nature of the coal to be cleaned.

OSTI ID:
5520970
Journal Information:
Coke Chem. USSR (Engl. Transl.); (United States), Vol. 5; Other Information: Translated from Koks Khim.; No. 5, 22(1980)
Country of Publication:
United States
Language:
English