Pink Fused Alumina

Product Specification: Pink Fused Alumina (Chrome Corundum)

1. Product Overview

Pink Fused Alumina, also known as Chrome Corundum or Artificial Ruby, is a high-performance abrasive and refractory material. It is an electrically fused solid solution primarily composed of alpha-Al₂O₃ with the addition of Chromium Oxide (Cr₂O₃). The incorporation of chromium oxide imparts the material with a distinctive pink to rose-red color and significantly enhances its toughness and thermal stability compared to White Fused Alumina.

2. Key Characteristics

*   Color: Pink, Rose-Red, or Purple-Red (depending on Cr₂O₃ content).
*   Primary Composition: α-Al₂O₃-Cr₂O₃ solid solution.
*   Hardness: High hardness, comparable to White Fused Alumina. Knoop Hardness: ~2160 HK; Mohs Hardness: ~9.0.
*   Toughness: Superior to White Fused Alumina and slightly lower than Brown Fused Alumina. The Cr₂O₃ content increases the grain's tenacity and reduces brittleness.
*   Thermal Stability: Excellent resistance to high temperatures and thermal shock.
*   Microstructure: The Cr₂O₃ forms a continuous solid solution with Al₂O₃, resulting in a dense and stable crystal structure.

3. Manufacturing Process

The product is manufactured through a high-temperature electric arc furnace fusion process. High-purity calcined Alumina (Al₂O₃) is mixed with precise amounts of Chromium Oxide (Cr₂O₃) or Chromium-bearing salts. This mixture is then melted at temperatures exceeding 2000°C. The molten liquid is cooled and crystallized to form the solid solution, which is subsequently crushed, graded, and processed into various particle sizes.

4. Available Grades and Specifications

We offer a range of Chrome Corundum products tailored to specific application needs:

*   Low Chrome: Cr₂O₃ content typically 0.2% - 0.45%.
*   Medium Chrome: Cr₂O₃ content typically 0.45% - 1.0%.
*   High Chrome: Cr₂O₃ content typically 1.0% - 2.0% or higher (up to 30% for specialized refractory applications).
*   Particle Sizes:
    *   Fused Lumps: 3-8mm, 5-10mm, etc.
    *   Grains: Standard FEPA (F4 - F220) and ANSI (4 - 240) grit sizes.
    *   Powders & Micropowders: W63 - W0.5 and finer.

(Note: Specific chemical composition tables and physical property data can be provided upon request.)

5. Primary Applications

Due to its unique combination of hardness, toughness, and thermal stability, Pink Fused Alumina is widely used in the following fields:

*   Abrasive Industry:
    *   Grinding Wheels: Manufacture of vitrified and resin-bonded grinding wheels for precision grinding of hardened steel, alloy steel, and hardened cast iron.
    *   Finishing: Ideal for tool grinding, precision grinding, profile grinding, and internal grinding where a superior surface finish is required.
    *   Polishing: Used as a loose abrasive for polishing and lapping applications.
*   Refractory Industry:
    *   Refractory Bricks: Used to produce Chrome Corundum Bricks (Cast or Sintered) for severe environments.
    *   Castables: As an aggregate in Chrome Corundum refractory castables.
    *   Applications: Glass furnace forehearth roofs, bottoms, and plungers; slag lines in steel teeming ingots; gasifier furnaces in the petrochemical industry; and high-temperature zones of zinc smelting electric furnaces. It offers excellent resistance to molten slag, glass melt, and chemical corrosion.

6. Advantages over White Fused Alumina

*   Higher Toughness: Less prone to chipping or fracturing during grinding.
*   Better Thermal Shock Resistance: Maintains structural integrity under rapid temperature changes.
*   Improved Sintering Properties: In refractory applications, it promotes better ceramic bonding.

7. Packaging and Storage

*   Packaging: Standard export wooden drums, jumbo bags (1 MT), or kraft paper bags (25kg/50lb). Custom packaging is available.
*   Storage: Store in a dry, well-ventilated area away from moisture and chemical contamination.

For further technical details, MSDS (Material Safety Data Sheet), or specific test reports, please contact our sales department.