Caustic Soda
Sodium hydroxide (NaOH), commonly known as Caustic Soda, is a strong base and is one of the most widely used chemicals in the industry either as a raw material or as an auxiliary chemical. Caustic soda is produced by the electrolysis of brine. In the electrolytic cell, brine (sodium chloride solution) is decomposed to chlorine at the anode and to a sodium hydroxide solution and hydrogen at the cathode. About 200 TPD of caustic soda will be purchase by NALCO; the rest can be supplied as 48% lye (liquid) or as flakes (solid).
Industrial Uses of Caustic Soda
Chemical Industry
- Production of chemicals like sodium hypochlorite, soda ash, and phosphates.
- Used in the manufacture of detergents, soaps, and surfactants.
- pH regulation in chemical processes.
Paper & Pulp Industry
- Used in pulping and bleaching processes.
- Helps in removing lignin from wood fibers.
Textile Industry
- Used for scouring cotton, removing natural oils, and bleaching fabrics.
- Important in dyeing processes.
Aluminum Production
- Key in the Bayer process to extract alumina from bauxite.
Petroleum & Soap Industry
- Neutralizes acids and refines petroleum products.
- In soap making, reacts with fats/oils to form soap (saponification).
Water Treatment
- Adjusts pH of water to prevent corrosion and scaling.
Other Uses
- Manufacture of drain cleaners and industrial cleaners.
- Used in textile and leather processing.
Food Industry
- Used in peeling fruits/vegetables and processing certain foods (like soft drinks or chocolate).
Safety Note
- Highly corrosive: can burn skin and eyes.
- Must be handled with PPE (gloves, goggles, aprons).
- Reacts violently with acids and organic compounds.
- Transported in 25Kg Bags