Sustainable electrochemical processes-controlled extraction of valuable metal ions from liquid metal mines

Abstract

The sustainable extraction of valuable metal ions from liquid metal mines, such as seawater, brine, and wastewater, offers a promising solution to the challenges posed by limited terrestrial mineral resources and their uneven geographical distribution. Electrochemical processes, renowned for their energy efficiency, adaptability to diverse raw materials (enabling direct ion extraction from various water sources), modularity (allowing flexible scaling), and environmental compatibility, are emerging as pivotal technologies in this field. Despite significant advancements, a comprehensive review focusing on the regulation and optimization of these processes remains limited. This review addresses this gap by exploring sustainable electrochemical processes-controlled extraction techniques, including capacitive deionization, pulse electrochemistry, flow batteries, and photoelectrochemical methods. For example, in the extraction of uranium from seawater, the developed half-wave rectification AC chemical method has achieved remarkable results in the extraction of uranium from seawater. The extraction rate of uranium reached 1932 mg g⁻¹, which is nine times higher than that of the physical and chemical adsorption method. At the same time, the kinetic speed was increased by four times, and the recovery rate of uranium after desorption reached 96.2 %. We emphasize the key regulatory parameters governing ion extraction performance and provide an in-depth analysis of the advantages and limitations of each method, particularly in extracting high-value metal ions such as lithium, uranium, strontium, and other heavy metals. Finally, the review outlines the current challenges and future prospects of these sustainable electrochemical processes for efficiently recovering valuable metal ions from liquid metal mines.