Asbestos is a fibrous form of many minerals and hydrous magnesium silicates. The name can also fibrous forms of iron and calciumare used. Asbestos fibers can be formed or processed in different tissues. Because it is flammable and a poor conductor of heat, asbestos was widely used to make products such as fireproof clothing for fire protection and thermal insulation products like hot water pipes. The first use of asbestos word from Pliny the Elder in the first century AD, and the substance was introduced as the second century BC. The Roman people made cremation wicks and clothes from asbestos, and a few centuries later, a famous person named Marco Polo announced its usefulness as cloths.
Asbestos has two main classes, serpentine and amphibole, the first relatively small. Chrysotile, the type of snake that about 95% of world supplies of asbestos materials, of which three quarters is used in Quebec. Other large deposits are located in southern Africa. United States of America, California, Arizona and Vermont are the major producing states of asbestos, but had the most deposits of the United States no commercial value.
Asbestos can using various methods of mining, but the most common method is surface mining. Only 6% of the mined ore that contain usable fibers.
Separate classified the mineral fibers by crushing, air intake and screening machines, and in this process in different lengths, or types. The most commonly used classification, Quebec Standard Test Method, divides the fiber into seven groups, the longest and the shortest in group one, called the asbestos produced in the group of seven. The length of the fiber and the chemical compositions of the mineral determine the kind of commodity that can be made of asbestos. The fibers were used in fabrics, usually rayon or cotton, and the shortest for molded parts such as gaskets and pipes.