Metallogenic process of ion adsorption REE ore based on the occurrence regularity of La in kaolin

Abstract

The occurrence of rare earth elements on clay mineral surfaces and the metallogenic mechanism is significant for mining and the leaching of ion adsorption REE ore. Through experimental isothermal adsorption of La onto the kaolin surface, it was found that the unit adsorption capacity could be divided into three stages according to the La concentration in solution: a) when the concentration of La in solution is 0–0.69 mmol/L, the adsorption capacity of La on kaolin increases rapidly with the rising of La concentration; b) when the concentration is 0.69–1.69 mmol/L, the adsorption capacity of kaolin to La tends to be flat; and c) when the concentration is more than 9.95 mmol/L, the adsorption capacity of kaolin to La increases linearly. The occurrence of La on the kaolin surface was studied by desorption experiments. It was found that with increasing La concentration, the water-soluble phase La is initially adsorbed up to a maximum adsorption of 0.259 mg/g, followed by the ion-exchange phase La up to a maximum adsorption of 0.175 mg/g. Finally, when the concentration of La in solution is >9.95 mmol/L, the colloidal phase La appeared. The metallogenic process of ion adsorption REE ore is revealed through the adsorption experiment of La on kaolin surface and the “three-phase La desorption” experiment.