Brown aluminum oxide and garnet sand are commonly used blasting media when blast cleaning surfaces. There are great differences between the two in terms of production process, grinding performance, and use.
1. Different production processes
Brown aluminum oxide is artificially produced, and its main raw materials are bauxite clinker, iron filings, and anthracite. This time, the raw material is smelted into a semi-molten state at high temperature in an electric arc furnace, and after crystallizing to a certain extent, water is added to cool it to make a brown aluminum oxide block. Then the brown aluminum oxide blocks are broken and ground to obtain the required brown aluminum oxide grits and brown aluminum oxide powder.
Garnet is a natural abrasive whose main source is garnet ore. Common garnet mines are iron aluminum garnet, magnesium aluminum garnet, spessartite garnet, calcium aluminum garnet, etc. Among them, iron aluminum garnet is the preferred source as abrasive. Natural garnets exist in rock mines, lake mines, beach mines, etc. The production of garnet is to directly crush, clean and screen the garnet ore.
2. Different grinding performance
The grinding force and grinding effect of brown aluminum oxide are related to the grade of brown aluminum oxide. The higher the alumina content, the higher the grinding power and hardness. The hardness of the first-grade brown fused alumina is Mohs 9.0, corresponding to more than 95% alumina content, the hardness of the second-grade brown fused alumina is Mohs 7.0-8.5, the corresponding alumina content is 70-80%, and the hardness of the third-grade brown fused alumina is Mohs 7.0-8.0 , corresponding to the alumina content of 50-65%.
The grinding force and grinding effect of garnet are related to the grade of the garnet vein. The hardness of high-grade garnet can reach Mohs 8.0-8.5, and the low-grade garnet has associated minerals such as omphacite, etc., and the hardness is relatively low. .
3. Different uses
Brown aluminum oxide is generally used for sandblasting work that requires quick cleaning, and can also be used for fine grinding such as sandblasting of tools, sandblasting of semiconductor components, etc.
Brown aluminum oxide is also a good refractory material. For the production of refractory clay, castables and aggregates, etc.
First-grade brown aluminum oxide is a commonly used abrasive for the production of abrasive products, used in the production of ceramic grinding wheels, resin grinding wheel cutting discs, etc.
Garnet is mainly used for large-scale sandblasting such as sandblasting and rust removal of ships and steel parts. 80 mesh garnet can also be used for water jet cutting. In the past, some grinding wheel factories used garnet to replace brown aluminum oxide to produce cutting discs, but obviously the quality of the grinding wheels produced was very poor.
