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Black corundum

The main raw material is black alumina, which contains aluminum oxide (AI2O3) with a content of 70% to 80%, contains more impurities such as silicon oxide and titanium oxide. Is a new environmentally friendly material.

Production Process

Raw material sorting → electrolytic smelting → crushing → ferromagnetic separation → screening → physical and chemical inspection → finished product packaging → inventory


  1. Freedom grinding, such as floor polishing before plating metal parts, aluminum products.
  2. Bicycle, motorcycle, sewing machine, clock parts.
  3. Polishing and sandblasting .
  4. Antiskid pavement and coal mine under storage material of choice.


Hardground moderate, high toughness, high temperature, thermal performance characteristics of a given temperature. A density of 3.5g / cm3. Maximum use temperature of 1850 ℃, a melting point of 2050 ℃. Mohs hardness of 9.0.

Black corundum performance

Black corundum, also known as low-aluminum corundum, is a gray-black crystal with α-Al2O3 and iron spinel as the main ore phase produced by smelting bauxite in an electric arc furnace. It is characterized by a low Al2O3 content. And there is a certain amount of Fe2O3 (about 10%), so it has the characteristics of moderate hardness, high toughness, high temperature resistance, and stable thermal performance.

Black corundum is mostly used for free grinding, such as grinding and rough grinding before electroplating. It is mainly used for polishing and sand blasting of stainless steel, metal products, optical glass, bamboo and wood products. It is also a new abrasive for manufacturing resin wheels, cutting blades, and abrasive cloth.

Technical index


Main chemical composition
Al2O3 Fe2O3 SiO2


First level

≥85 6-9 5-8 2-4
Secondary ≥80 >9 >8


Black Corundum Display Video

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