Brown Corundum And Garnet Difference

Brown corundum abrasives and garnet abrasives are widely used abrasives, the main chemical composition of brown corundum is Al2O3, its content is 95.00%-97.00%, and contains a small amount of Fe, Si, Ti and other oxides, most commonly brown and black. The main chemical composition of garnet includes SiO2(36-40%), Al2O3(20-24%), FeO(22-24%), as well as Fe2O3, TiO2, MgO, CaO and other components, color is divided into brown, black, red, green and so on.

Due to the similarity of appearance color and chemical composition, in the production of grinding wheels, we will feel angry when the brown corundum abrasive is mixed with secondary sand, tertiary sand and even furnace skin, and the situation of garnet as primary sand is outrageous, which is not unheard of in the industry. Driven by interests, some unscrupulous manufacturers seek profits at the expense of reputation.
In terms of origin, brown corundum is made of bauxite, iron chips, coke (anthracite) by melting and reducing in electric arc furnace; Garnet is a natural non-metallic ore.
In terms of physical and chemical properties, brown corundum Al2O3 content is high, hardness is about 9.0, and fire resistance is good, while garnet Al2O3 content is low, hardness is 7.5-8.0, and corrosion resistance is good. In the field of sandblasting application, garnet abrasive can not only play the role of removal, but also protect the sandblasting object from scratches, and its performance is better than brown corundum; However, in the manufacture of abrasive tools, the wear resistance of brown corundum is obviously better than that of garnet.
In terms of cost price, garnet abrasives are made of natural raw stone after crushing and processing, and the price is lower; Brown corundum is bauxite, coke, iron filings, etc., according to a certain ratio of mixed melting, the production cost is significantly higher than garnet, the market price is also high.
Low grade VS high grade
Bauxite is the main raw material for smelting brown corundum, the main requirements for its chemical composition are alumina and silicon oxide content, and customers have other requirements for body density, calcium oxide, magnesium oxide content and so on.

In the past, under normal circumstances, brown corundum smelting enterprises require that the chemical content of alumina in bauxite is not less than 85(silicon content below 4.0). At present, it is basically difficult to buy the real 85 ore on the market, most of which are 80 to 83 ore (silicon content above 7.0). First, with the continuous mining, high-quality bauxite resources are increasingly scarce; The second reason is that the environmental pressure has led to the basic production of raw ore mining, and most bauxite kilns have been forced to shut down because of environmental protection standards. This has resulted in a tight supply of bauxite on the market, most bauxite manufacturers are shovelled, and the aluminum-silicon ratio is also declining, resulting in corundum smelting operations, prolonged time, increased power consumption, and a straight rise in production costs.
In fact, there is no so-called true or false bauxite, the key lies in the chemical composition content, grade, whether shoddy.
The above is just a list of individual cases, in the abrasives industry, abrasives and other raw material suppliers of fraud and adulteration behavior is distressing (even abrasive products manufacturing enterprises procurement, quality inspection departments and raw material enterprises collude with fake adulteration), and desperate part of abrasive products and other downstream manufacturers take the initiative to require raw material suppliers to fraud, adulteration, in order to lower production costs, Fight a price war. In the abrasive abrasives industry, the stability of the product is widely criticized, which is not unrelated to fraud and adulteration.