Brown Fused Alumina: Detailed Analysis of Characteristics, Processing, and Applications
Release time:
2025-08-21
Brown fused aluminum (BFA) is a synthetic corundum abrasive made primarily from high-alumina bauxite, processed through high-temperature smelting in an electric arc furnace, followed by cooling, crushing, magnetic separation, and screening. It is named for its brownish-brown color.
1. Main Components and Characteristics
Chemical Composition: Aluminum oxide (Al₂O₃) accounts for over 94%, with small amounts of impurities such as iron oxide (Fe₂O₃), silicon oxide (SiO₂), and titanium.
Mohs Hardness: 9.0, second only to diamond and silicon carbide.
Density: 3.90-4.10 g/cm³.
Toughness: High, with strong impact resistance and stable cutting force.
High Temperature Resistance: Can withstand temperatures of approximately 1900°C and is not prone to decomposition or deformation.
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2. Production Process
Raw Material Preparation: Selected high-alumina bauxite. Some products may contain coke and iron filings as reducing agents.
Electric Arc Furnace Smelting: Reduction smelting at temperatures above 2000°C causes the aluminum oxide to crystallize into corundum.
Cooling and Crushing: Large blocks of brown corundum are cooled and crushed into particles.
Magnetic Separation: Removes free iron and magnetic impurities.
Screening and Grading: Sorting into different sizes based on particle size standards (such as F, P, and fine powder).
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3. Main Applications
Abrasive Industry: Used in the manufacture of grinding wheels, sandpaper, abrasive belts, coated abrasives, bonded abrasives, etc.
Sandblasting and Shot Blasting: Used in metal rust removal, surface treatment, glass etching, etc.
Refractory Materials: Used in the manufacture of high-temperature furnace linings, casting shells, and spray coatings.
Grinding and Polishing: Used in the precision processing of ceramics, stone, glass, optical lenses, etc.
