Development of Interfacial Solar Evaporation Technologies for Brine Treatment and Mineral Recovery.

The growing demand for critical minerals has increased interest in developing more efficient and sustainable technologies for mineral recovery from natural and industrial brines. Conventional solar evaporation ponds remain widely used for brine mineral recovery while can be constrained by slow evaporation rates, long processing cycles, and substantial land requirements. Interfacial solar evaporation (ISE), which localizes solar energy at the water-air interface, offers a promising approach to accelerate brine concentration and potentially facilitate mineral separation, extraction and recovery. However, translating ISE from laboratory-scale demonstrations to practical brine mining remains challenging, particularly because realistic brines contain high salinity and complex ionic compositions that can substantially affect water transport, salt crystallization, and evaporation performance. This perspective discusses recent advances and future opportunities for promoting the application of ISE technologies in brine treatment and mineral recovery. We highlight the development of salt-resistant interfacial solar evaporators, emerging strategies for selective mineral extraction and crystallization, and the critical effects of multivalent ions and complex brine compositions on evaporation performance. Future opportunities should focus on developing scalable and durable ISE systems that can maintain stable performance under realistic outdoor conditions. Advances in system engineering and long-term field validation will be important for translating ISE from laboratory-scale studies toward practical brine treatment and critical mineral recovery.