Bayer Process
Refining Bauxite into Aluminum Hydroxide (Al(OH)₃)
Process Steps
1. Crushing & Grinding
Bauxite is crushed and ground into fine particles
2. Digestion
Mixed with hot NaOH under high temperature & pressure (140–250°C)
Reaction: Al(OH)₃ + NaOH → NaAlO₂ + 2H₂O
3. Clarification
Impurities removed as red mud
4. Separation
Red mud is separated
5. Washing & Filtration
Al(OH)₃ is washed & filtered to produce alumina (Al₂O₃)
Key Points
• Produces high-purity alumina
• Caustic soda is recycled
• Red mud is the main by-product
• Most widely used alumina refining process
The standardized sequence of steps, technologies, and methodologies used to transform raw materials or inputs into high-quality finished products.