The concept of classification and extender pigment production process

Pigment, usually referred to as fillers, from becoming important in this century, they include many compounds derived from nature, directly manufactured or obtained as a byproduct. These substances are mainly barium, calcium, magnesium, or aluminum salts, oxides of silicon or aluminum, or from the front two complexing substances derived double salts, in coatings, inks, linoleum, plastic materials, paper and paper coating , linoleum, putty, buffing and scrubbing materials, rubber products, cement, plastics, ceramics and other fields have a wide range of uses. Their usefulness and are close to white opaque pigment, extender pigment and the type and quantity of the use of the traditional industry development will have a closer. These pigments have two continuity: a refractive index lower than 1.75 (typically 1.45 to 1.70), the color is white or nearly white. Other properties of the pigment a wide range, such as the relative density and capacity values, particle shape, particle size, particle size distribution, oil absorption, chemical activity and so on. inganic pigments
Since 1930, with the development of production technology, extender pigments in color, uniformity, particle size, particle size distribution, surface treatment, etc. There are a lot of improvements. Pigment was first obtained from the nature, and the present by another chemical process byproducts resulting pigment gradually increased, many of which require specialized pigment production. The pigment used with calcium carbonate, magnesium silicate, aluminum silicate, calcium sulfate, crystalline silica, diatomaceous earth, barium sulfate.
Calcium carbonate is mainly obtained from limestone, or as a byproduct of some manufacturing processes, or directly on the lime slurry with carbon dioxide reaction. Natural calcium carbonate can be manufactured by a dry milling method or wet milling. Dry grinding dry grinding method good product through the air separator separating oversize particles return regrinding. Using the wet method can produce finer, more vivid, screening a better grade. Limestone in the presence of water under the conditions of grinding, the use of conical or tubular grinder mill products continuous release, centrifuge separation, oversize particles and feed back with regrinding. Another important advantage of the wet milling is the flotation by further improved product color and chemical purity. plastic processing aid