Emery, silicon carbide, and brown fused alumina are all materials with high hardness widely used in various industries, including abrasives, grinding tools, ceramic manufacturing, and electronic devices. However, due to differences in their chemical properties and composition, distinctions exist among the three. In this article, I will analyze them in terms of raw materials, applications, properties, and chemical characteristics.
Brown Fused Alumina: Produced by melting and reducing aluminium oxide, carbon materials, and iron scraps in an electric arc furnace, resulting in brown synthetic corundum. Its primary chemical component is aluminium trioxide (Al2O3), ranging from 95.00% to 97.00%, with trace amounts of iron, silicon, titanium, etc.
Emery (Corundum): a product of melting quartz and carbonaceous materials (mainly quartz sand and coke). Pure emery corresponds to the formula of SiC (Si 70.4%, C 29.6%).
Silicon Carbide: Since it is naturally scarce, silicon carbide is mainly produced synthetically. Common methods involve mixing quartz sand with coke, utilizing silica and petroleum coke, adding table salt and sawdust, placing the mixture into an electric furnace, heating it to around 2000°C, and obtaining silicon carbide powder through various chemical processes. For detailed production procedures, refer to How to Produce Silicon Carbide?
Brown fused alumina is used to manufacture ceramics and resin-bonded abrasives, as well as for grinding, polishing, sandblasting, and precision casting. Additionally, it is used in the manufacturing of sophisticated refractory materials.
Emery is suitable for grinding high-carbon steel, high-speed steel, and stainless steel, among other applications. White fused alumina can also be used for precision casting and advanced refractory materials.
Brown fused alumina possesses characteristics such as high purity, good crystallinity, strong fluidity, a low linear expansion coefficient, and corrosion resistance. It is widely used on the surfaces of hardware parts made of stainless steel, carbon steel, aluminium alloy, etc., effectively removing burrs and flash.
Compared to brown fused alumina, emery has higher purity, good self-sharpness, resistance to acid and alkali corrosion, high-temperature resistance, and stable thermal performance. Its hardness is higher than that of
brown fused alumina, providing a strong cutting force suitable for removing burrs and flash on metal or non-metal surfaces. Moreover, emery can achieve a polishing effect during grinding, categorizing it as a medium-polishing abrasive.
Corundum, silicon carbide, and brown corundum have different chemical properties due to their chemical composition, crystal structure, and bonding methods between elements. See the following table for details:
Brown Fused Alumina (Corundum)
Aluminum Oxide (Al2O3)
Carbon (C) and Silicon (Si)
Aluminum Oxide and Chromium Oxide (Al2O3-Cr2O3)
Tetragonal Crystal System (α-Al2O3)
Hexagonal Crystal System (SiC)
Tetragonal Crystal System
Very High (9 Mohs Hardness Scale)
High Hardness (9-9.5 Mohs Hardness Scale)
High Hardness (9 Mohs Hardness Scale)
Acid-Alkali Corrosion Resistance
Resistant to Acid, Poor Alkali Resistance
Metal and Non-metal Surface Treatment, Grinding, Polishing
Metal Processing, Ceramic Manufacturing, Grinding of Electronic Components
Surface Treatment of Hardware Parts, Grinding
These are the main differences among brown fused alumina, silicon carbide, and emery. The selection should be based on the specific requirements of the industry.
What are brown fused alumina, silicon carbide, and emery, and how do their main components differ?
Brown fused alumina is primarily composed of aluminium oxide and is produced through the melting and reduction of aluminium oxide, carbon materials, and iron scraps. Silicon carbide is mainly composed of carbon and silicon and is synthesized by mixing quartz sand and coke. Emery, or corundum, contains aluminium oxide and chromium oxide, produced by melting and reducing aluminium oxide, carbon materials, and iron scraps.
In which fields are brown fused alumina, silicon carbide, and emery widely used?
Brown fused alumina is commonly used in the manufacture of ceramics, resin-bonded abrasives, grinding, polishing, sandblasting, precision casting, and advanced refractory materials.Silicon carbide is largely employed in functional ceramics, advanced refractory materials, and high-temperature ceramics. abrasives, and metallurgical raw materials. Emery finds applications in surface treatment, grinding, and polishing of hardware parts.
How do the performance characteristics of brown fused alumina, silicon carbide, and emery differ?
Brown fused alumina exhibits high purity, strong fluidity, low linear expansion coefficient, and corrosion resistance. Silicon carbide is characterized by high hardness, good self-sharpness, resistance to acid and alkali corrosion, and high-temperature stability. Emery has high purity, good self-sharpness, resistance to acid and alkali corrosion, high-temperature resistance, and stable thermal performance.
How do the chemical properties of brown fused alumina, silicon carbide, and emery differ?
The chemical composition, crystal structure, hardness, self-sharpening, acid-alkali corrosion resistance, high-temperature resistance, and thermal conductivity of brown fused alumina, silicon carbide, and emery differ due to variations in their chemical composition, crystal structure, and bonding between elements.
In practical applications, how should one choose between brown fused alumina, silicon carbide, and emery, and what are their specific application areas?
The choice between brown fused alumina, silicon carbide, and emery should be based on industry-specific requirements. Brown fused alumina is suitable for metal and non-metal surface treatment, grinding, and polishing. Silicon carbide is used in metal processing, ceramic manufacturing, and the grinding of electronic components. Emery is widely used in the surface treatment and grinding of hardware parts. Selection should consider factors such as hardness, corrosion resistance, and other performance requirements.