Calcination Process
Transforming Aluminum Hydroxide (Al(OH)₃) into Alumina (Al₂O₃)
1. Feed Material
Aluminum Hydroxide – Al(OH)₃ (from Bayer Process)
2. High-Temperature Heating
• Rotary kiln
• Fluidized bed calciner
• Temperature: 1000–1600°C
3. Chemical Reaction
2 Al(OH)₃ → Al₂O₃ + 3 H₂O
• Water vapor (H₂O) is released
• Structure changes to stable α-Al₂O₃
4. Final Product – Calcined Alumina (Al₂O₃)
Key Characteristics
• High purity (≥99% Al₂O₃)
• High melting point (~2050°C)
• Very hard and abrasive
Purpose
Remove chemically combined water and transform crystal structure
The standardized sequence of steps, technologies, and methodologies used to transform raw materials or inputs into high-quality finished products.