Crushing/grinding

Ores must be ground to a point of complete or nearly complete liberation, Even though this might possiblv be accomplished bv coarse crushing, grinding to finer than 10 mesh in all cases and finer than 48 mesh in most cases is necessaiw prior to Rotation, (Grinding is done in closed circuit with classifiers. 

Fischer, John Practical Pneumatic Conveyor Design, Chemical Engineering, June 2, 1958, p. 114. Crushing, Grinding, and Screening... 

Bond, F. C., Crushing Grinding Calculations, Part I, Brit. Chem. Eng., 6 378 (1961)... 

The characteristics of the minerals sold depend upon the physico-chemical characteristics of the ore body from which they are extracted. Processing of the minerals before sale can be simple (mainly crushing, grinding and classifying), but may also be very sophisticated for the most expensive mineral types. 

Crushing grinding operations, employing the types of equipment described above, are used in the processing preparation of a wide variety of expl compns and their ingredients Refs 1)W.L.Badger, "Elements of Chemical... 

Modern machines for dry size reduction in fine size rang) 6)L.T.Work, IEC 39, 11-31 (1947) (Crushing Grinding) (See also succeding "Size Reduction under Unit Operations)... 

A collection of loose, unattached, primary particles or aggregates of relatively small size is usually called a powder. It is recommended that the word powder is used if the largest dimension of the individual entities is smaller than 1 mm. The shape of the particle should be described (sphere, flake) and the method of its preparation specified (crushing, grinding spray drying). 

The usual first beneficiation operation is size reduction, which may be achieved by crushing, grinding, or disaggregating by scrubbing and washing. Particle size reduction liberates mineral species so that they can be separated. Size separation usually follows size reduction. When gangue minerals are more indurated than the phosphate, it is often... 

Limestone, Ground, is produced as a fine, white to off white, microcrystalline powder mainly consisting of calcium carbonate. It is obtained by crushing, grinding, and classifying naturally occurring limestone benefited by flotation and/or air classification. It is stable in air. It is practically insoluble in water and in alcohol. The presence of any ammonium salt or carbon dioxide increases its solubility in water, but the presence of any alkali hydroxide reduces its solubility. 

After initial concentration by crushing, grinding and froth flotation, bastnasite is treated with 10% HCl to remove calcite, by which time the mixture contains around 70% lanthanide oxides. This is roasted to oxidize the cerium content to Ce on further extraction with HCl, the Ce remains as Ce02, whilst the lanthanides in the (-T3) state dissolve as a solution of the chlorides. 

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