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Comminution is the reduction of solid materials from one average particle size to a smaller average particle size, by crushing, grinding, cutting, vibrating, or other processes.〔 In geology, it occurs naturally during faulting in the upper part of the Earth's crust. In industry, it is an important unit operation in mineral processing, ceramics, electronics, and other fields, accomplished with many types of mill. In dentistry, it is the result of mastication of food. In general medicine, it is one of the most traumatic forms of bone fracture. Within industrial uses, the purpose of comminution is to reduce the size and to increase the surface area of solids. It is also used to free useful materials from matrix materials in which they are embedded, and to concentrate minerals. == Energy requirements == The comminution of solid materials consumes energy, which is being used to break up the solid into smaller pieces. The comminution energy can be estimated by: *Rittinger's law, which assumes that the energy consumed is proportional to the newly generated surface area; *Kick's law, which related the energy to the sizes of the feed particles and the product particles;〔Kick, F.M. Das Gesetz der proportionalen Widerstände und seine anwendung felix. Leipzig, Germany. 1885.〕 *Bond's law, which assumes that the total work useful in breakage is inversely proportional to the square root of the diameter of the product particles, () theoretically that the work input varies as the length of the new cracks made in breakage.〔Bond, Fred C. (1975) ''It Happened to Me'', Ch. 130. Amazon.com. Retrieved May 29, 2011.〕〔Bond, F.C. The third theory of comminution.Trans. AIME, vol. 193, 1952. pp. 484–494.〕 *Holmes's law, which modifies Bond's law by substituting the square root with an exponent that depends on the material.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Comminution」の詳細全文を読む スポンサード リンク
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