A Chinese-led research team announced that they discovered a naturally occurring rare earth element mineral in a fern. The discovery of monazites in living plants in a study conducted by the Guangzhou Institute of Geochemistry offers a new model for the “direct recovery of high-value rare earth elements in an environmentally friendly way.”
This discovery is the earliest reported example of rare earth elements crystallizing in the mineral phase in a hyperaccumulator plant (plants that can accumulate metals on themselves), the researchers said.
Sustainable rare earth supply through phytomining
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The researchers emphasized that the study confirms the feasibility of phytomining and offers a new plant-based approach. Phyto-mining, hyperaccumulator It is an environmentally friendly method that uses plants that can retain metals in the soil in plant tissues with hundreds or even thousands of times more accumulation than normal.
In this method, target metals are recovered after harvest from plants grown in metal-rich soils. Thus, dependence on traditional mining decreases and environmental and geopolitical risks decrease.
Monazite mineral and its properties
Monazite is a phosphate mineral rich in rare earth elements and contains elements such as cerium, lanthanum and neodymium. The crystallization of monazite, which generally forms at high temperature and pressure, in plants under surface conditions, offered scientists an alternative mineralization method.
Monazite has a high melting point, exhibits excellent optical emission properties, and is resistant to glass-induced corrosion and radiation damage. Thanks to its mechanical, physical and thermal properties, it can be used in coating materials, light-emitting devices, lasers, ionic conductors and radioactive waste management.
Study method and findings
In the research, evergreen fern named Blechnum orientale and surrounding soil samples collected from rare earth element deposits in Guangzhou, China were analyzed.
The findings showed that rare earth elements are concentrated first in the plant’s leaflets, followed by the root and petiole. The minerals crystallized in the extracellular (outer membrane of the plant) tissues, which do not enter the plant’s cells and provide detoxification (the agent that does not let harmful substances in).
Scientists stated that the formation of monazite resembles a chemical garden process. In this process, metal salts self-organize in the water environment and form vegetative structures, enabling the formation of complex structures.
A green and circular model
Guangzhou Institute of Geochemistry announced that the study offers a new way to sustainable use of rare earth elements. Researchers stated that with hyperaccumulator plants, high-value elements can be recovered, polluted soils can be cleaned and the ecology can be re-established.
In this way, “cleaning and recycling occur simultaneously”, creating an environmentally friendly circular model.
Source: Newspaper Oxygen