Selective recovery of critical materials in zero-liquid discharge supercritical water desalination

• Published in: Desalination Vol. 537
• Main Authors: Yoon, Tae-Jun, Sharan, Prashant, Craddock, Erica Powers, Lewis, Jeremy Charles, Matteson, John Anthony, Seong, Jong Geun, Singh, Rajinder Pal, Maerzke, Katie A., Currier, Robert Patrick, Findikoglu, Alp Tugrul
• Format: Journal Article
• Language: English
• Published: United States Elsevier 25-05-2022
• Subjects: brine mining; critical materials; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; ion speciation; selective recovery; supercritical water; zero-liquid discharge desalination
• ISSN: 0011-9164

Zero-liquid discharge desalination techniques are being actively studied as alternative means to produce drinkable water and recover valuable resources without polluting the environment. Supercritical water desalination is one of such alternatives that can overcome the technical and environmental challenges in standard desalination techniques. In addition to these attractive features, this work explores the possibility of utilizing supercritical water desalination for the selective recovery of strategic (critical) materials as co-products. Here, to validate the technical and economic feasibility of the process, we prepared model brine solutions that consist of sodium, neodymium, and different anions and conducted a series of desalination experiments. The results were analyzed experimentally and theoretically and were utilized to evaluate the economic feasibility of the process. When a few tens or hundreds of parts-per-million critical materials are dissolved in the feed, the proposed method becomes more cost-effective in producing critical materials than existing technologies. In addition, it does not discharge any concentrated contaminants while producing drinkable water. These results suggest that supercritical water desalination can recover critical materials while producing freshwater in an economically feasible fashion.