The Future of Mining Rare Earth Elements Sustainably
2022-02-24
source:AZO Mining
Rare earth elements (REEs) comprise 17 metallic elements, made up of 15 lanthanides on the periodic table:La，Ce，Pr.........
Cerium is the most common REE and more abundant than copper or lead.They are instead found in four main uncommon rock types; carbonatites, which are unusual igneous rocks derived from carbonate-rich magmas, alkaline igneous settings, ion-absorption clay deposits, and monazite-xenotime-bearer placers deposits.Since the late 1990s, China has dominated REE production, utilizing its own ion-absorption clay deposits, known as the ‘South China Clays’.Rare earth elements are used for all sorts of hi-tech equipment, including computers, DVD players, cell phones, lighting, fiber optics, cameras and speakers, and even military equipment, such as jet engines, missile guidance systems, satellites, and anti-missile defense.In 2010, China announced it would reduce REE exports to fulfill its own rise in demand, but also maintain its dominant position for supplying hi-tech equipment to the rest of the world.Phosphogypsum Fertilizer Rare Earth Elements Capture ProjectTherefore, researchers at Penn State University, have devised a multistage approach using engineered peptides, short strings of amino acids that can accurately identify and separate REEs using a specially developed membrane.The design is led by computational modeling, developed by Rachel Getman, principal investigator and associate professor of chemical and biomolecular engineering at Clemson, with investigators Christine Duval and Julie Renner, developing the molecules that will latch on to specific REEs.Chemical engineering professor Lauren Greenlee, claims that: “today, an estimated 200,000 tons of rare earth elements are trapped in unprocessed phosphogypsum waste in Florida alone.”The new project will focus on recovering them in a sustainable way and may be rolled out on a larger scale for environmental and economic benefits.National Science Foundation Project FundingAlternative Ways to Recover Rare Earth ElementsAlthough a simple process, leaching requires a high quantity of hazardous chemical reagents, so is undesirable commercially.Another common way for REEs to be recovered is through agromining, also known as e-mining, which involves the transportation of electronic waste, such as old computers, phones, and television from various countries to China for REE extraction.Although often touted as a sustainable method of recycling materials, it is not without its own set of problems that still need to be overcome.The Penn State University Project has the potential to overcome some of the problems associated with traditional REE recovery methods if it can satisfy its own environmental and economic objectives.
