Brown aluminum oxide is a brown artificial corundum produced by smelting and reducing bauxite, carbon and iron filings in an electric arc furnace. The main chemical components of brown fused alumina are Al2O3, with contents of 95.0% and 97.0% respectively, and also contain small amounts of Fe, Si, Ti and other elements. Brown corundum is the most basic abrasive. Artificial abrasives made of white aluminum oxide have an aluminum oxide (Al2O3) content greater than 99%, and contain small amounts of iron oxide, silicon oxide and other components, and are white. So, what is the difference between brown aluminum oxide and white aluminum oxide?
1. Different raw materials: The raw materials of brown fused alumina are bauxite, anthracite and iron pins. The raw materials of white aluminum oxide are alumina powder.
2. Different uses: Brown aluminum oxide can be used to make ceramics, resin high-consolidation abrasives, grinding, polishing, sandblasting, precision casting, etc., and can also be used to make advanced refractory materials. White corundum is suitable for grinding fine-grained abrasives such as high-carbon steel, high-speed steel and stainless steel. White aluminum oxide can also be used for precision casting and advanced refractory materials.
3. Different performance: Brown aluminum oxide has the characteristics of high purity, good crystallization, strong fluidity, low linear expansion coefficient, and corrosion resistance. White aluminum oxide has the characteristics of high purity, good self-sharpening, acid and alkali corrosion resistance, high temperature resistance, and stable thermal performance. In comparison, the hardness of white corundum is higher than that of brown corundum.
4. Different composition: Although both brown aluminum oxide and white aluminum oxide contain alumina, the alumina content of white corundum is above 99%, and the alumina content of brown corundum is about 95%.
5. Different colors: Since the alumina content of white aluminum oxide is higher than that of brown aluminum oxide, the color of white corundum is white, and that of brown corundum is brown-black.
6. Different production methods: White aluminum oxide is produced from alumina powder (the same raw material as electrolytic aluminum), while brown aluminum oxide is produced from calcined bauxite.
7. Different users: White fused alumina is used by some high-end users because it has better cutting force and polishing effect. It is mostly used for carbon steel, alloy steel, malleable cast iron, hard bronze, etc., while brown corundum is widely used in the market and is also used in large quantities in the market. It is mostly used for hardened steel, high-speed steel, high-carbon steel, etc.
White fused alumina has strong cutting force and is used to remove metal or non-metal burrs, pre-burrs, etc. It has the function of polishing the surface of parts and is a medium polishing abrasive. Brown fused alumina will never remove burrs on the surface of hardware parts such as stainless steel, carbon steel, and aluminum alloy. The grinding of brown corundum is not as fine and bright as white corundum.
Why is the price of brown fused alumina higher than that of white fused alumina?
Everyone is a little confused when seeing this.
After comparing the performance of brown fused alumina and white fused alumina in various aspects, it is obvious that white corundum is better, and the price of white corundum is usually twice that of brown corundum.
In fact, it is because brown fused alumina has strong irreplaceability in many application fields.
Brown aluminum oxide has strong wear resistance, erosion resistance and toughness. In places where molten iron and steel need to flow and there is erosion and wear (such as iron grooves), brown corundum has its unique advantages, which are more reflected in the application of its particle size and aggregate. Compared with white corundum, the content of titanium oxide in brown aluminum oxide is higher, which makes brown fused alumina have stronger toughness, which makes the anti-erosion performance of brown aluminum oxide better than other materials.
According to the practice verification of dozens of refractory manufacturers, 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 an ideal aggregate and filler for brown fused alumina refractory materials.
Moreover, brown fused alumina consumes more electricity than white fused alumina during the smelting process, and the price of raw materials has been rising with the supply and demand relationship in the past one or two years, resulting in the price of brown corundum in the market being higher than other raw materials such as white corundum and sintered corundum.
