Short notes on Caustic Soda

Caustic soda is obtained by the chemical conversion of soda ash and also by electrolysis of brine. There are 40 plants producing about 7 lakh tons of caustic soda per annum. About 40 per cent of the production is accounted by Western India, 30 per cent by the South and remaining scattered over other regions.

The present capacity is about 8 lakh tons with annual growth rate around four per cent. The capacity creation has been in excess of demand.

The important centres of production are Ahmadabad, Porbandar, Mumbai, Kolkata, Kota, Rishra, Dehri on Sone, Delhi, Mettur, and A1 waye, Nagpur, Titagarh, Durgapur, Thane and Amlai. The main producers are Calico Chemicals, Ahmadabad; Dhrangadhra Chemical Works, Porbandar; JK Chemi­cals Ltd., Thane; Century Rayons, Kalyan; National Organic Chemicals, Mumbai; Rajasthan Vinyl Chemi­cals Ltd., Kota; West Paper Mills, Dandeli; Orient Paper Mills, Amlai; Nepal Chemicals, Nagpur; Tata Chemicals Ltd., Mithanpur; Titagarh Paper Mills Co., Titagarh; DCM, Delhi; and Durgapur Indus­tries Board, Durgapur.

The Production of caustic soda increased from 1.01 lakh tons in 1960-61 to 3.71 lakh tons in 1970-71, 5.78 lakh tons in 1980-81 and 10.73 lakh tons in 1992-93. The cost of production of caustic soda in India is higher than other countries (cf. India Rs. 1.9, 000/ ton; USA Rs. 11,250/ ton; China Rs. 11,850/ton and Saudi ArabiaRs. 8,825/ton). It is mainly because in the West the caustic soda industry is a chlor-alkali industry where caustic soda is a by-product and chlorine is the main product. Reverse is true in India. Recent glut of caustic soda has made the problem more acute.