Brown corundum, also known as diamond sand, is mainly made from bauxite and coke (anthracite) through high-temperature smelting in an electric arc furnace. Its main chemical components are AL2O3 and TiO2 rings containing a small amount of SiO2 and Fe2O3. Its microhardness is HV1800-2200, and its toughness is higher than SiC. Grinding tools made from it are suitable for grinding metals with high tensile strength, such as sandblasting, grinding, polishing of various general steel materials, malleable cast iron, hard bronze, and can also manufacture advanced refractory materials.