Salt: A possible constraint to growth of Indian chlor-alkali industry? - Ravi Ra

For the chlor-alkali industry – manufacturing caustic/chlorine or soda ash – salt is one of the most important raw materials, ranking only behind electric power (for caustic/chlorine) and limestone (for soda ash). What matters to them are not just salt’s availability and price, but also its quality.

This is particularly so for caustic soda, which is almost exclusively made in India by the membrane process. The life of the membrane and the reliability of operations crucially hinges on the quality of salt – its purity, and, just as importantly, its impurity profile.

Much of the salt in India is produced in the unorganised sector, through the solar evaporation route, using rudimentary, labour-intensive techniques. Getting the industry to invest in upgrading quality to suit exacting quality norms remains a challenge.

Rising demand

Globally, annual salt production is of the order of 280-mt, and represents a business valued at about $20-bn at current prices. About 60% of the output goes to meet industrial requirements and about 30% for human/animal needs. India is the world’s third largest salt manufacturer, with an annual output of about 28-mt – about 10% of global production – but trails far behind the two leading salt producers, China (65-mt) and USA (44-mt). Of the total salt availability in India in 2017-18, about 8-mt went for edible purposes, about 15-mt for industrial production and about 10-mt was exported. The caustic soda and soda ash industries account for bulk of industrial usage, but there are other uses such as in textile processing, making soaps & detergents, food processing, water softening, leather curing etc.

Annual salt demand in India is rising by 5-6%, driven largely by rise in industrial consumption, particularly for caustic soda and soda ash. At this rate, India’s requirement at the end of the decade will likely be of the order of 33-mt. Unless production rises at this clip, industrial users may face shortages, given that a significant quantity of salt is exported at higher prices than realised domestically.

Unlike the rest of the world, nearly all of the primary salt production in India is through solar evaporation of seawater or stranded brines. Simply put, the process involves crystallisation of salt from seawater that has been concentrated by solar evaporation. Nearly three quarters of production comes from one single state, Gujarat, and that too in just six regions – Kutch, Jamnagar, Saurashtra, Little Rann of Kutch, South Gujarat and Maliya. Tamilnadu and Rajasthan are two other two important states, accounting for about 10% each, and Andhra Pradesh produces some salt as well. It is largely for this reason that nearly all of the soda ash industry and a significant portion of the caustic soda industry are located in these states.

Fluctuating supply

Salt output is dependent on the vagaries of nature and fluctuates year-on-year; production has at times dropped to 18-mt and at others zoomed close to 30-mt. With the area under salt