In news: In a step towards productive utilisation of bauxite residue, commonly known as the ‘Red Mud’ , the Ministry of Mines today organised an interactive workshop called ‘Waste To Wealth’.
What is red Mud?
- Red mud is a solid waste generated during the aluminium production process. This is an environmental concern due to the presence of impurities such as caustic soda and other minerals.
- Six major constituents of red mud– Silicon, Aluminium, Iron, Calcium, Titanium and Sodium, apart from an array of minor elements.
- Red mud contains impurities such as caustic soda and other minerals.
- The Bayer process is the principal industrial means of refining bauxite to produce alumina (aluminium oxide).
- Bauxite, the most important ore of aluminium, contains only 30–60% aluminium oxide (Al2O3), the rest being a mixture of silica, various iron oxides, and titanium dioxide.
- The aluminium oxide must be purified before it can be refined to aluminium metal.
- This process is still used to produce nearly all of the world’s alumina supply.
Environmental problems associated with red mud:
- Increasing problems of land cost, storage and pollution.
- Its high alkalinity makes it extremely corrosive and damaging to soil and life forms and also contaminates groundwater.
Utilisation of red mud:
- In production of materials such as cement, bricks, roofing tiles and glass ceramics.
- To treat acidic soils and retain certain nutrients, such as phosphorus in agriculture.
- It can be used as an additive in ferrous metallurgy.
- It can be used as a feedstock for making water and sewage treatment agents.