Source:
The high-density minerals in the Georgia kaolin mines are potential sources of rare-earth elements, including the heavy rare-earth elements that are in high demand for many important uses and are mostly imported to the United States from China, according to a study led by Georgia State University and Thiele Kaolin Co. Kaolin is a type of clay.
Rare-earth elements are used to make critical products, including rechargeable battery electrodes and permanent magnets.
There are 17 rare-earth elements, which include the 15 elements of the lanthanide series (atomic numbers 57 to 71 on the periodic table), plus scandium (Sc) and yttrium (Y). The heavy rare-earth elements are from gadolinium (Gd) to lutetium (Lu), atomic numbers 64 to 71 on the periodic table.
Thiele Kaolin Co. mined for kaolin in two quarries near Sandersville, Ga., and provided Georgia State researchers with the leftover mineral samples, or grit, for analysis. The minerals present were identified using X-ray diffraction, scanning electron microscopy and chemical analysis. The findings, published in the journal Clays and Clay Minerals, suggest a new, potential source of rare-earth elements, including the less common heavy rare-earth elements.