Harnessing Mixed Salt Production from Brine for Value Addition: A Review of Sustainable Practices in the Indian Context

India’s unique geography and favourable climatic conditions make it highly suitable for large-scale solar salt production. India is also witnessing the rapid emergence of seawater desalination plants to meet growing freshwater demands. Both the salt industry and desalination sector rely on brine as a primary raw material, making their integration strategically important. Utilizing desalination rejects in salt production offers a dual benefit: addressing the problem of brine disposal while simultaneously enhancing salt productivity. After salt harvesting, the remaining concentrated bittern is often underutilized despite its economic potential. This bittern can be further processed to recover mixed salts, stoichiometric combinations of sodium, potassium, and magnesium chlorides or sulphates, which are worthy raw materials for Na-K-Mg chemicals. This paper presents review of the processes involved in mixed salt production, including analyses of the geochemical characteristics of the brines, their ionic compositions, and their effect on the type and quality of the resulting mixed salt. In addition to conventional evaporation method, alternative methods such as chemical precipitation and electro-membrane processes have also been discussed. Furthermore, the paper highlights modern practices and outlines future research directions aimed at reducing environmental impact and ensuring the long-term viability of the mixed salt production from concentrated brine. • Integration of desalination plant and solar saltworks for resource recovery • Concentrated brine (bittern) valorization for mixed salt recovery • Brine geochemical origin and ionic composition effects mixed salt quality/type • ZLD solution for desalination reject with value-added salts recovery