Abstract: A method for hydrometallurgical extraction of rare earth elements and niobium from a an ore or a flotation concentrate containing rare earth elements, niobium, iron and alkali earth metals, the method comprising removal of the alkali earth metals using an acidic solution of a pH in a range between about 1 and about 6, leaching the rare earth elements; precipitation of the rare earth elements from a resulting pregnant leach solution using sodium hydroxide, sodium carbonate and sodium bicarbonate; physically separating metal hydroxides from a resulting leach residue containing metal hydroxides, iron oxide, silicate, and pyrochlore; removing the iron oxide by physical beneficiation and then by atmospheric acid leaching; and recovering niobium from a clean solid residue by pressurized acid leaching.

Abstract: A method for hydrometallurgical extraction of rare earth elements and niobium from a an ore or a flotation concentrate containing rare earth elements, niobium, iron and alkali earth metals, the method comprising removal of the alkali earth metals using an acidic solution of a pH in a range between about 1 and about 6, leaching the rare earth elements; precipitation of the rare earth elements from a resulting pregnant leach solution using sodium hydroxide, sodium carbonate and sodium bicarbonate; physically separating metal hydroxides from a resulting leach residue containing metal hydroxides, iron oxide, silicate, and pyrochlore; removing the iron oxide by physical beneficiation and then by atmospheric acid leaching; and recovering niobium from a clean solid residue by pressurized acid leaching.

Abstract: A method for purification and separation of mixed elements, comprising at least a first free flow electrophoresis separation chamber, wherein a solution of the mixed elements is passed through the first separation chamber, an electric field submitted perpendicular to the solution flow and separating mobile ions of the solution based on electrophoretic mobility. A continuous method comprises selecting a complexing ligand, and controlling the temperature and pH of the solution.