U.S. researchers tap bacterial modification instead of chemicals to process critical raw materials.
Scientists at Cornell University in New York State have developed a new process for separating rare earths. Instead of the usual chemicals, a bacterium called Shewanella oneidensis is used.
Through its metabolic processes, the microbe can selectively bind to rare earths and separate them from each other and the surrounding ore. In this so-called biosorption, Shewanella oneidensis prefers europium, the researchers write. By studying the bacterial genome, the interdisciplinary team was able to identify 242 genes related to rare earth biosorption. This knowledge will now be used to optimize the process, for example, by increasing the preference for rare earth elements other than europium. Compared with conventional separation processes, biosorption is more environmentally friendly and saves costs and space since significantly smaller plants are required, explains study author Buz Barstow.
Most rare earth processing occurs in China, whereas the U.S. used to dominate this sector. In addition to rare earth mining, the United States wants to bring downstream processing of the critical raw materials back home. Biosorption could contribute to a stable domestic supply of rare earths in the future, Barstow said. As a next step, the research team aims to develop a pilot-scale facility by 2028.
Read more: Given the growing demand for critical raw materials and an increasing interest in more environmentally friendly mining methods, research is being conducted worldwide into alternative production processes. In addition to bacteria, these include proteins, electric currents, and even sponges.
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