A perspective on molecular recognition technology for recovering critical metals from minerals and processing wastes

Abstract

With the transition to a low-carbon economy due to the rising global climate, advances in high technology and the proliferation of electronic devices, the demand for critical metals will continue to increase in the future. Since critical metals are characterized by low crustal content and difficult to isolate, the efficient recovery of critical metal elements from associated minerals and electronic device wastes has attracted much attention. Molecular recognition technology (MRT) is a process in which target ions achieve mutual binding under specific conditions through the synergistic action of forces such as hydrogen bonding, chelation, surface complexation and ion exchange, which has directed the design of various functionalized adsorbents for critical metals recovery nowadays. This review begins with describing the current status of recycling of several typical critical metals, including gallium, germanium, rhenium, indium, scandium. Then the mechanism and application of MRT in selective recovery of critical metals are discussed with the example of recovery of dilute metals. This article review reveals that: i) the processes involved in critical metal separation are increasingly recognized as more complex and diverse, posing greater challenges for their recovery; ii) selectively binds to target ions are based on the design of structures tailored to match the target molecules; iii) the development of highly selective adsorbent materials lies at the heart of adsorption separation technology, and the integration of MRT with adsorbents offers a promising approach to enhance adsorption performance effectively. Inspired by the application of MRT, suggestions are made for adsorbent design with selective recovery of critical metals.