Introduction of white corundum, brown corundum and black corundum

       White corundum is made of industrial alumina powder and refined using modern new and unique process technology. Sandblasting abrasives have the characteristics of short grinding time, high efficiency, good benefits and low price. The main ingredients are: Aluminum Oxide (Al2O3) with a content of more than 98%, and a small amount of iron oxide, silicon oxide and other ingredients. It is white and is made by high-temperature melting above 2000 degrees in an arc and then cooling. It is crushed and shaped, magnetically separated to remove iron, and sieved into various particle sizes. It has a dense texture, high hardness, and sharp-angled particles.
    White corundum has a slightly higher hardness than brown corundum and slightly lower toughness. It has high purity, good self-sharpening, strong grinding ability, low heat generation, high efficiency, acid and alkali corrosion resistance, and good high temperature thermal stability. Grinding tools made of white corundum sand are suitable for grinding fine-grained abrasives such as high-carbon steel, high-speed steel and stainless steel. White corundum segment sand can also be used for precision casting and advanced refractory materials.

    Brown corundum, also known as diamond sand, is a brown artificial corundum made by melting and reducing three raw materials: bauxite, carbon material and iron filings in an electric arc furnace. The main chemical composition of brown corundum is AL2O3, with a content of 95.00%-97.00%, and it also contains a small amount of Fe, Si, Ti, etc. Brown corundum is the most basic abrasive, and is widely used because of its good grinding performance, wide application range and low price. Brown corundum is smelted at high temperature in an electric arc furnace. The grinding tools made of it are suitable for grinding metals with high tensile strength, such as various general steels, forgeable cast iron, hard bronze, etc., and can also be used to manufacture high-grade refractory materials. Brown corundum has the characteristics of high purity, good crystallization, strong fluidity, low linear expansion coefficient and corrosion resistance. This product has the characteristics of no explosion, no powdering and no cracking during the application process. In particular, its cost-effectiveness is far higher than that of traditional brown corundum, making it the best aggregate and filler for brown corundum refractory materials. The general particle size number is F4~F320.

Black corundum: A black corundum with an aluminum oxide (AI2O3) content of 70% to 80% and containing more impurities such as silicon oxide and Titanium Oxide.
Black corundum, also known as low-aluminum corundum, is a gray-black crystal with α-Al2O3 and iron spinel as the main mineral phases obtained by smelting bauxite in an electric arc furnace. It is characterized by a low Al2O3 content and a certain amount of Fe2O3 (about 10%). Therefore, it has the characteristics of moderate hardness, high toughness, high temperature resistance, and stable thermal performance. It is mostly used for free grinding, such as grinding and rough grinding before electroplating of products. It is mainly used for polishing and sandblasting of stainless steel, metal products, optical glass, bamboo and wood products. It is also a novel abrasive for manufacturing resin grinding wheels, cutting discs, and emery cloth.

Corundum is a mineralogy name. There are three main variants of corundum Al2O3, namely α-Al2O3, β-Al2O3, and γ-Al2O3. The hardness of corundum is second only to diamond and cubic boron nitride.
Corundum is mainly used for high-grade grinding materials, bearing materials for watches and precision machinery. Ruby, as a laser emission material, is an artificial crystal. Ruby and sapphire are both corundum minerals. In addition to the starlight effect, only translucent-transparent and colorful corundum can be made into gemstones. Red is called ruby, while other colors of corundum are collectively called sapphire in the business.
Corundum (Corundum) that meets the conditions of gemstones in gemology is called ruby ​​(Ruby) and sapphire (Sapphire).