Quick answer: Salt recovery from brine extracts saleable or reusable salts, mainly sodium chloride and sodium sulphate, from industrial concentrate instead of disposing of them. Selective and fractional crystallisation, eutectic freeze crystallisation and evaporative crystallisation separate individual salts to a defined purity, turning a waste stream into a valorised product that supports circular-economy goals.
Frequently asked questions
What salts can be recovered from industrial brine?
The most commonly recovered salts are sodium chloride and sodium sulphate. Depending on the source, other salts and recovered water can also be extracted. Sodium chloride can be reused as regenerant, chlor-alkali feed or de-icing salt, while sodium sulphate serves detergent, glass and textile markets.
How does selective crystallisation work?
Selective, or fractional, crystallisation exploits how different salts respond to temperature and concentration. By staging cooling and evaporation, one salt is precipitated at a time. For mixed brines, sodium sulphate is often crystallised first on cooling as Glauber’s salt, then sodium chloride is recovered from the remaining liquor.
Is eutectic freeze crystallisation better than evaporation?
Eutectic freeze crystallisation can use less energy per unit than evaporation because freezing water needs less energy than boiling it, and it recovers both pure salt and pure water. However, it is less mature at industrial scale and needs low-temperature plant. The best choice depends on brine chemistry, scale and energy prices.
Can recovered salt be sold?
It can, if it meets the target market’s specification and clears end-of-waste and REACH requirements. Lower-value uses like de-icing tolerate more impurities; chemical or chlor-alkali feedstock demands tight limits on calcium, magnesium, sulphate and metals. Washing and controlled crystallisation are often needed to reach saleable quality.
Does salt recovery support circular-economy goals?
Yes. Recovering salt converts a waste into a reusable product, cuts virgin salt and reagent purchases, and reduces the salinity load on receiving waters. EU circular-economy and industrial-emissions policies reward this waste minimisation, and internal reuse of recovered salt can close material loops on site.
Sources and further reading
- European Commission, Circular Economy Action Plan
- European Commission, EU Water Framework Directive (Directive 2000/60/EC)
- European Commission, Industrial Emissions Directive and BAT reference documents (BREF)
- European Chemicals Agency (ECHA), REACH and end-of-waste guidance
- Rijkswaterstaat and Unie van Waterschappen, discharge permitting information
Talk to Brine Consulting for an independent assessment of whether salt recovery pays for your brine.
Written by the Brine Consulting advisory team. The Brine Consulting advisory practice includes George Iacovou, a salicultural technologist with more than 23 years in crystallization, MVR systems and salt processing, and Prof. Basel Abusharkh, a specialist in brine valorization, ZLD and high-recovery desalination. Meet our experts.