Page 125 - CW E-Magazine (5-8-2025)

Point of View

Raising productivity, upgrading quality &

diversifi cation – musts for Indian salt industry

Salt, aka sodium chloride, is a lowly-priced commodity of great importance for human consumption and as industrial raw material. In
pre-independent India taxes on the commodity led to an upswell of discontent, which ultimately led to freedom from colonial rule. While dietary
deficiency in salt can be life-threatening (as seafarers of yesteryears well knew), its high level in processed foods is blamed for many bodily ills.

Salt is an important industrial raw material, used for manufacture of industrial chemicals, particularly soda ash and caustic soda. India
is a leading exporter of salt, though not a maker of markets.

Salt manufacture
Manufacture of salt in its various forms – edible, vacuum, industrial, table salt, fortified with iodine – supports thousands of households,
particularly in coastal Gujarat and Tamil Nadu, and in Rajasthan, which three States together account for 95% of all salt production and nearly all
exports. Nearly three-quarters of salt comes from just six regions of Gujarat – Kutch, Jamnagar, Saurashtra, Little Rann of Kutch, South Gujarat
and Maliya. Much is produced in the unorganised sector by solar evaporation of seawater using rudimentary, labour-intensive techniques. The
industry provides direct employment to nearly 0.1-mn persons, working in 12,000 salt works, of which only 400 are large-scale.

Salt manufacturing is simple and begins with building embankments for storing salt water soon after the monsoon recedes. In 2-3 months,
the water dries up and salt forms a thick layer. The top layer, being the purest, is used for edible purposes, while the remaining layers are
cleaned and sent for industrial use.

The principal impurities in salt are divalent ions – mainly, calcium, magnesium and sulphate – and need to be removed for use in the
chlor-alkali industry. Over the last decade, there has been significant improvement in the quality of salt produced, catalysed by the efforts
of the Bhavnagar-based Central Salt and Marine Chemicals Research Institute (CSMCRI), a CSIR lab. While the quality of Indian salt was
once said to below that from Australia and Mexico, today salt of over 99.5% purity can be obtained directly in solar salt fields even without
mechanical washing.

Significant progress has also been made in utilisation of sea bittern (the brine left after recovery of salt) as a resource for bulk marine
chemicals, particularly bromine. Integrated processes wherein salt production is followed by recovery of sulphate of potash and magnesia
from kainite-type mixed salt (composite salt with chlorides & sulphates) has also been developed.

Global salt market
The global market for salt is about 350-mt, and China is the largest consumer with 36% share, followed by North America, Western
Europe and India. About 60% of salt demand is in the chemical industry (mainly chlor-alkali), followed by demand for deicing (13%) and in
the food industry (11%). About 50-mt of salt is traded across the seas and is limited by the fact that the cost of transportation is comparable
to the price of salt. Australia, India and China are the major exporters, while the US and Asian markets (China, South Korea, Japan, Taiwan
and Indonesia) are major importers. While North American chlor-alkali producers have access to captive or merchant brine sources of salt,
about half of European producers buy it in the merchant market.

To be competitive in global markets salt producers must have a low manufacturing cost position and, just as importantly, access to a
seaport from where the material can be shipped. Large consumers also need to be near ports, and this is the case, for example, with caustic
soda producers in coastal China, who together account for 20% of the country’s production.

With much of the new chlor-alkali capacity in the world expected to come up in Asia, the importance of this salt-importing market will
rise. Salt capacity additions in Australia, the Middle East (Oman, Saudi Arabia, Qatar), and to some extent India and Pakistan will ensure
there is enough available to meet the incremental demand.

Raising productivity
India is the third largest producer of salt globally with production of around 30.8-mt in FY23. About a third of the salt consumed is used for
industrial purposes, primarily in the manufacture of caustic soda and soda ash. Exports show significant volatility and reached 11.8-mt in FY23.
With the chlor-alkali sector expected to grow faster than its historical pace, there are fears that salt supply could become a crunch.

Chemical Weekly August 5, 2025 125

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