SYSTEM AND METHOD FOR RARE EARTHS EXTRACTION

摘要

It is described a method for recovering rare earth elements from low grade ores including a first metal selected group containing at least one of iron and aluminum and a second metal selected from the group consisting of at least of the rare earth elements (lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, yttrium and scandium), the method comprising the steps of: (i) contacting the ore with sulfuric acid to obtain sulfates of the first group of metals, (ii) subjecting the mixture to high temperatures in order to convert the first group of sulfates into phosphates or other stable species and the second group into sulfates, (iii) adding water to the cool mixture, selectively dissolving the rare earth elements and (iv) subjecting the rare earth solution to a purification process.