What are the characteristics of white corundum, brown corundum and red corundum?

What is white corundum?

White corundum is made of industrial aluminum oxide powder as raw material, which is cooled after melting at a high temperature of more than 2000 degrees in the arc. It is crushed and shaped, removed by magnetic separation, and divided into a variety of particle sizes. Its texture is dense, its hardness is high, and the particles form sharp angles.

Characteristics of white corundum

White corundum is crystallized by electromelting. It has high purity, good self-sharpness, acid and alkali corrosion resistance, high temperature resistance and stable hot state performance. White corundum hardness is slightly higher than brown corundum, toughness is slightly lower, high purity, good self-sharpness, strong grinding ability, small heat, high efficiency, acid and alkali corrosion resistance, high temperature thermal stability.

Scope of application of white corundum

White corundum is suitable for the manufacture of ceramic, resin-consolidated abrades, grinding, polishing, sandblasting, precision casting (precision casting corundum), etc., and can also be used to manufacture high-grade refractory materials. Suitable for a variety of high-end products, technology or hardware and other products surface beautification treatment, sandblasting surface white without any impurities, without cleaning trouble. Fine white corundum can be used as polishing head.

What is brown alumina?

Brown corundum, also known as carborundum, is a brown artificial corundum made of bauxite, carbon materials and iron chips by melting and reducing in an electric furnace, so it is named for this. The main chemical composition of brown corundum is Al2O3, its content is 94.5%-97%, and contains a small amount of Fe, Si, Ti and so on.

Characteristics of brown corundum

In the application process, it has the characteristics of non-initiation, non-pulverization and non-cracking, especially its cost performance is much higher than that of traditional brown corundum, and it becomes the aggregate and filler of brown corundum refractory.

Application scope of brown corundum

Brown corundum particle size sand is manually selected brown corundum block, using rolling, ball milling, Barmack and other equipment processing, particle size F8-F325, mainly used for polishing, grinding, industrial grinding, etc., can also be washed according to customer requirements, pickling and other processing methods, to meet the different needs of customers.

What is red corundum?

The composition of red corundum is mainly α-alumina, also known as chrome corundum, ruby. Now the market is mostly artificial red corundum.

Characteristics of red corundum:

Red corundum added 22% chromium on the basis of white corundum, made by electric arc furnace melting, the color is purple. The hardness is slightly higher than that of brown corundum, similar to white corundum, and the microhardness can be 2200-2300Kg/mm2. Toughness is higher than white corundum, slightly lower than brown corundum.

Scope of application of red corundum

The abrasive tools manufactured by it are suitable for grinding high-carbon steel, high-speed steel and thin-walled parts, and abrasive can also be used as grinding, polishing materials, precision casting sand, spraying materials, chemical catalyst carriers, special ceramics, high-grade refractory materials, etc.

Mainly from the point of view of hardness and toughness:

Hardness: White corundum > Red corundum; Brown corundum;

Toughness: Brown corundum > Red corundum; White corundum.

In addition to high hardness, white corundum will not be brought into the color when grinding, which is especially suitable for grinding some demanding metal products.

Brown corundum is the most common corundum series abrasive sand. Red corundum is somewhere in between.