Currently, environmentally friendly processes for processing raw materials containing rare earth elements (REE) are being actively developed. Microorganisms play an important role in the biogeochemistry of REE, but the nature of the interaction of micromycetes with REE remains poorly understood. The study examines the potential of extracting REES from their insoluble forms using microscopic fungi. Using the example of the soil micromycete Aspergillus niger, the possibility of converting difficult-to-dissolve neodymium oxide NdO into water- and alcohol-soluble (ethyl and isopropyl) neodymium compounds is shown. The morphology and structure of A. niger cells and the distribution of insoluble and soluble forms of the rare earth element before and after bio-leaching were studied using scanning electron microscopy (SEM). Bio-leaching by micromycetes was modeled using the direct contact method. X-ray fluorescence analysis of extracts after bio-leaching showed the presence of neodymium. These studies will help unlock the potential of microscopic fungi for their application in an environmentally friendly technology for the extraction of REE based on bio-leaching. This may serve as a basis for the development of an environmentally friendly alternative to currently used methods using strong inorganic acids or toxic substances.
Belov et al. (Wed,) studied this question.