Brown corundun A

    Brown corundum, also known as diamond sand, is a type of artificial corundum with a brown color. It is mainly made by high-temperature smelting of bauxite, coke (or anthracite), and iron filings in an electric arc furnace. The main chemical component of brown corundum is aluminum oxide (Al ₂ O3), with a content ranging from 94.5% to 97%, and containing small amounts of elements such as Fe, Si, Ti, etc. ‌

    Preparation Method

    Brown corundum is produced by high-temperature smelting of bauxite, coke (or anthracite), and iron filings in an electric arc furnace. The specific process includes purification, impurity removal, crystallization, sorting, crushing, magnetic separation, screening and other processing methods at high temperatures above 2250 ℃, ultimately producing products of various particle sizes.

    Physical and Chemical Properties 

    Brown corundum has the following physical and chemical properties:

    High hardness: The microhardness is between 1800-2200 kg/mm ².

    High density: Bulk density ≥ 3.85 g/cm ³.

    High temperature resistance: The fire resistance can reach up to 1850 ℃ to 1900 ℃.

    High purity: good crystallization, strong fluidity, low coefficient of linear expansion, and corrosion resistance.

    Strong self sharpening ability: low heat generation rate, high grinding ratio, and minimal adhesion during use.

    Application area

    Brown corundum is widely used in multiple fields due to its excellent properties:

    Abrasives and grinding tools: 

    Suitable for grinding various general steel, malleable cast iron, hard bronze, etc., making grinding wheels, sand belts, sandpaper and other grinding tools.

    Refractory materials: used for manufacturing advanced refractory materials such as refractory bricks and castables.

    Sandblasting: Used for cleaning, rust removal, and finishing of workpieces such as aluminum profiles, copper profiles, and glass.

    Other applications: such as wear-resistant flooring, functional fillers, filter media, hydraulic cutting, etc.

    These characteristics of brown corundum make it important in industrial production, especially in the manufacture of advanced refractory materials, making it the best aggregate and filler for brown corundum refractory materials.