How to distinguish between brown fused alumina and black fused alumina?

- Mar 25, 2021-

1. Alumina content

The alumina content of brown fused alumina is between 75% and 95%, while that of black fused alumina is between 45% and 75%. The alumina content is much lower than that of brown fused alumina.


2. Different colors


The color of brown corundum is mostly brown, sometimes black and sometimes red; black corundum is black with metallic color.


3. Performance characteristics


Brown corundum has moderate hardness, high toughness, good self-sharpening, low sand consumption and can be recycled and reused, and the polished parts are good; and it has stable chemical composition, wear resistance, acid and alkali resistance. The abrasive shell has a shell-shaped fracture and sharp corners, which can form new corners and edges during continuous crushing and classification, so that the grinding ability will not be weak.

Black corundum has good self-sharpening properties, low heat generation during grinding, good finish of processed parts, and good hydrophilicity.


4. Product hardness


Since the content of alumina in brown corundum is higher than that of black corundum, the hardness of brown corundum is also greater than that of black corundum.


5. Use object


Brown corundum is the use of universal abrasives, special alloys, ceramics, linings (walls and tubes) of iron-making blast furnaces; physical and chemical utensils, spark plugs, heat-resistant and oxidation-resistant coatings. Black corundum is particularly suitable for the grinding and polishing of stainless steel workpieces and the manufacture of oilstone and abrasive paste.