Recently researchers from University of New Brunswick did researches and confirmed: Phosphate tailing may be the potential source of rare earth elements. They added that” Assuming the production of neodymium, dysprosium and other rare earth elements are in the potential shortages in America, it would threaten the energy security of America”. Rare earth elements are absolutely necessary parts in solar energy, wind energy, advanced automobile technology, smart phone and other modern electronic products.
The researchers pointed that, recycling rare earths from phosphogypsum is a potential solution. In 2017, around 28 million tons phosphorite are exploited in America. The rare earth content in phosphorite wouldn’t be higher than 0.1%, however there are one hundred thousand tons rare earth elements in global phosphogypsum waste every year.
Regular refinery method cause millions of tons of toxic and acidic pollutants. The research group use minerals and organic acid, including a biologic acid mixture, to refine six rare earth elements, yttrium, cerium, neodymium, samarium, europium and ytterbium. This biologic acid mixture consisted of gluconic acid is produced through culturing glucose bacillus on basis of glucose by scientists lead by David Reed from Idaho National Laboratory.
Initially, they evaluated phosphogypsum that is prepared in the laboratory. The researchers from New Jersey and Lawrence Livermore National Scientists also took part in this study.
The result indicate using biologic acid to refine rare earth elements is better than pure gluconic acid at same condition that is pH(2.1) or same acidity. Additionally , the researchers plan to test biological acid in industrial phosphogypsum that is from production of phosphoric acid containing rare earth elements and other waste.