Brown corundum

Corundum with bauxite as raw material made of high temperature melting. Brown color, hardness, toughness. Corundum corundum is a kind of brown so named because of its iron. Corundum is pure alumina, when mixed with different materials show different colors when, as with Ming-red, titanium was strong blue, manganese was rosy, but iron is brown. Iron is considered harmful ingredients in corundum, so brown the cheapest in the corundum. Corundum is very hard (9), but slightly lower hardness of corundum, with the increase of iron content decreased, the proportion of 3.95 ～4.10, the high melting point, Refractoriness up to 2000 ℃ ～2050 ℃.
A large piece of corundum as abrasive industrial uses is, when the friction material by engineers looking for a variety of friction materials include it in a matter of course when the line of sight, the preferred when the number of lower-cost brown. Consumption ratio generally less than 3%, but the fineness demanding to 325 is appropriate, when the fineness of more than 500 projects, the maximum amount of up to 13%.
Chemical composition：