The proper term is micrometre, meaning one millionth of a metre, but micron or microns is the more commonly used term used by engineers and manufacturers working at very small scales. In the particle size environment micron is the unit of preferred choice to describe the average diameter of the individual particles being studied. Source: WIKIPEDIA,THE FREE ENCYCLOPEDIA

Micronization is the process of reducing the average diameter of a solid material's particles. Usually, the term micronization is used when the particles that are produced are only a few micrometres in diameter. However, modern applications (usually in the pharmaceutical's industry) require average particle diameters of the nanometer scale. Source: WIKIPEDIA, THE FREE ENCYCLOPEDIA

Traditional micronization techniques are based on friction to reduce particle size. Such methods include milling and grinding. A typical industrial mill is composed of a cylindrical metallic drum that usually contains steel spheres. As the drum rotates the spheres inside collide with the particles of the solid, thus crushing them towards smaller diameters. In the case of grinding, the solid particles are formed when the grinding units of the device rub against each other while particles of the solid are trapped in between. Source: WIKIPEDIA, THE FREE ENCYCLOPEDIA

Methods like crushing and cutting are also used for reducing particle diameter, but produce more rough particles compared to the two previous techniques (and are therefore the early stages of the micronization process). Crushing employs hammer-like tools to break the solid into smaller particles by means of impact. Cutting uses sharp blades to cut the rough solid pieces into smaller ones Source: WIKIPEDIA, THE FREE ENCYCLOPEDIA

Air classification can be defined as the means of 'modifying' the particle size distribution of a dry powder by using the aerodynamic drag forces of the air to separate the particles. More specifically it relates to the separation of a dry powder of mixed particle size into two distinct fractions: one above and one below a defined cut point. Source: WIKIPEDIA, THE FREE ENCYCLOPEDIA

Mesh size is often used in determining the particle size distribution of a granular material. For example, a sample from a truckload of peanuts may be placed atop a mesh with 5 mm openings. When the mesh is shaken, small broken pieces and dust pass through the mesh while whole peanuts are retained on the mesh. A commercial peanut buyer might use a test like this to determine if a batch of peanuts has too many broken pieces. This type of test is common in some industries, and to facilitate uniform testing methods, several standardized mesh series have been established. One well-known mesh series is the Tyler Equivalent. Tyler mesh size indicates exactly the number of openings per linear inch of mesh. For instance, a Tyler number 4 mesh will have 4 openings per linear inch, and 16 openings per square inch. This numbering system results in higher numbered meshes having smaller openings. The openings of adjacent mesh sizes in this series differ by a factor of. To calculate the size of the openings in a mesh the thickness of the wires making up the mesh material must be taken into account. Please see the mesh size comparison chart in our useful data table’s link. Powders and granular materials are sometimes described as having a certain mesh size (e.g. 30 mesh sand). By itself, this type of description is somewhat ambiguous. More precise specifications will indicate that a material will pass through some specific mesh, but will be retained by some specific tighter mesh. This type of description establishes a range of particle sizes. Source: WIKIPEDIA, THE FREE ENCYCLOPEDIA

Mohs' scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer material. It was created, in 1812, by the German mineralogist Friedrich Mohs and is one of several definitions of hardness in materials science. Mohs based the scale on ten minerals that are all readily available except the last one, diamond. The hardness of a material is measured against the scale by finding the hardest material that the given material can scratch, and/or the softest material that can scratch the given material. For example, if some material is scratched by apatite but not by fluorite, its hardness on Mohs scale is 4.5. The table below shows comparison with absolute hardness measured by a sclerometer. Mohs' is a purely ordinal scale with, for example, corundum being twice as hard as topaz, but diamond almost four times as hard as corundum. So, a diamond is the hardest naturally occurring substance known to man. Source: WIKIPEDIA, THE FREE ENCYCLOPEDIA

On the Mohs scale, fingernail has hardness 2.5; copper penny, about 3.5; a knife blade, 5.5; window glass, 5.5; steel file, 6.5. Using these ordinary materials of known hardness can be a simple way to approximate the position of a mineral on the scale.

Friability essentially means crumbability. That is to say that a substance can be reduced to fibers or finer particles by the action of pressure on its mass. The term is commonly used in reference to asbestos which is brittle enough to be reduced to small particles upon application of pressure. Of course, the term could also apply to any material that exhibits these properties. Some examples might include: clumps of dried clay, asbestos, graham crackers, perlite, and any other such substance as can be reduced by crumbling in the hand or otherwise by application of pressure. Source: WIKIPEDIA, THE FREE ENCYCLOPEDIA

An abrasive is a material that is used to smooth, machine, or, in some cases, roughen another softer material through extensive rubbing. Abrasives are used to remove surface materials such as metal, ceramics, glass, plastics and paint. Source: WIKIPEDIA, THE FREE ENCYCLOPEDIA

Some common examples of abrasive minerals are; aluminium oxide, zirconia alumina, silicon carbide, diamond dust, boron nitride, corundum and sand.

Attrition means wearing down or grinding by friction. Source: WIKIPEDIA, THE FREE ENCYCLOPEDIA