Abstract: A method for extracting rare earth elements and critical minerals including adding an acid to a mixture comprising organically bound rare earth elements. The mixture is maintained at a pH of 0.25 to 4 for a period of time, resulting in a liquor and a leached mixture. The liquor is removed from the leached mixture to form a dewatered cake. The dewatered cake is washed to form a washing liquid. The washing liquid is recycled to create a second slurry comprising organically bound rare earth elements.

Abstract: A method for extracting rare earth elements and critical minerals including adding an acid to a mixture comprising organically bound rare earth elements. The mixture is maintained at a pH of 0.25 to 4 for a period of time, resulting in a liquor and a leached mixture. The liquor is removed from the leached mixture to form a dewatered cake. The dewatered cake is washed to form a washing liquid. The washing liquid is recycled to create a second slurry comprising organically bound rare earth elements.

Abstract: A method for recovering rare earth elements (REE) from a leach solution. The method includes determining the concentration of a first plurality of contaminates in the leach solution, adding a first amount of oxalic acid to the leach solution and allowing it to react for a first period of time to form a first precipitant and a first liquor, maintaining the pH of the first liquor between 1.5 and 3 by the addition of an alkali base, removing the first precipitant, adding a second amount of oxalic acid to the first liquor and allowing it to react for a second period of time to form a second precipitant and a second liquor, maintaining the pH of the second liquor between 1.5 and 3 by the addition of the alkali base, and removing the second precipitant.