Method for removing aluminum from rare-earth feed liquid

Abstract

The invention discloses a method for removing aluminum from rare-earth feed liquid, belongs to rare-earth feed liquid treatment technology and aims to provide the method for removing the aluminum from the rare-earth feed liquid, of which the aluminum-removing effect is good, the aluminum-removing cost is low, the rare-earth recovery rate is high, the operation and control are convenient, the process is simple and the investment in equipment is small. The key point of the technical scheme mainly comprises the following steps of: (1) preparing an organic phase from 15 to 25 volume percent of naphthenic acid and 15 to 25 volume percent of alcohol-kerosene; (2) adding the prepared organic phase and the rare-earth feed liquid into a stirring tank in a volume ratio of 2-5:1, starting the tank, stirring and uniformly mixing; (3) adding alkaline solution into the mixed liquid obtained in the step (2) with stirring, wherein the total number of moles of the added alkali is 50 to 100 percent of that of rare-earth elements in the rare-earth feed liquid; and (4) after adding the alkaline solution, continuously stirring for a certain time, stopping stirring and standing for a certain time, wherein the solution is separated into an aqueous phase and an organic phase and the aqueous phase is the rare-earth feed liquid from which the aluminum is removed. The method is applied to aluminum removal for the rare-earth feed liquid.

Description

technical field [0001] The invention relates to a treatment technology of rare earth material liquid, more specifically, it relates to a method for removing aluminum from rare earth material liquid. Background technique [0002] In ion-adsorption rare earth ores, rare earth elements are adsorbed on the surface of clay minerals in an ion state. When leaching ionic rare earth ores, a large amount of aluminum ions in clay minerals enter the leaching solution along with rare earths. In the preparation of concentrates of early ion-adsorption rare earth ores, oxalic acid was used to precipitate rare earths in the leaching solution, and a large number of non-rare earth impurities including aluminum were removed. However, in recent years, the oxalic acid precipitation process of ion-adsorption rare earth ore leachate has been gradually replaced by ammonium bicarbonate precipitation. Although the cost of concentrate preparation has been greatly reduced, the non-rare earth impurities...

AI Technical Summary

Problems solved by technology

(2) Acid method: also known as oxalic acid precipitation method, adding oxalic acid into the rare earth solution, because the solubility of aluminum oxalate in the acidic solution is relatively large, so that the aluminum remains in the solution, this method has a good effect on removing aluminum and is suitable for separating a large amount of rare earth This method is generally used for the final step of feed liquid treatment. For the intermediate feed liquid, due to the complex conversion process, many process steps, high cost of impurity removal, large oxalate dissolution loss, and difficult oxalic acid wastewater treatment, it is not practical. significance

Thanks Al 3+ with RE 3+ The pH value at the beginning of hydrolysis is quite close, resulting in the simultaneous hydrolysis and precipitation of aluminum and rare earth, and the subsequent treatment of the resulting colloidal precipitate is very difficult

This method has low aluminum removal efficiency and large loss of rare earth, so the hydrolysis method cannot effectively remove aluminum

(4) Extraction method: The traditional extraction method is to use a volume ratio of 25% naphthenic acid-20% isooctyl alcohol-kerosene to form an organic phase, first add ammonia water or sodium hydroxide for saponification, and the saponification value is 0.35M, and then use a single Stir and mix the rare earth liquid with a pH value of 3.0 in a one-stage stirring tank or a multi-stage extraction tank, about 30% of the aluminum is extracted, but the extraction loss of the rare earth is more than 10%. , otherwise it will easily cause emulsification of the system and make the extraction process impossible