Method for recovering neodymium and iron from neodymium iron boron oil sludge

Abstract

The invention relates to a method for recovering neodymium and iron from neodymium iron boron oil sludge, belonging to the technical field of recycling of neodymium iron boron oil sludge. The method comprises the following steps of: dissolving the neodymium iron boron oil sludge by using hydrochloric acid and filtering undissolved substances, and then, controlling a certain pH value and reaction temperature after oxidizing through adding hydrogen peroxide; sequentially adding ammonium bicarbonate and ammonium hydroxide or hydrofluoric acid and ammonium hydroxide; co-precipitating a neodymium and iron sediment mixture through adsorption among rare earth carbonate, rare earth fluoride and iron hydroxide colloid according to the physical properties of the rare earth carbonate and the rare earth fluoride; and respectively roasting a filtered product at the proper decomposition temperature to obtain a neodymium and iron compound. A complex wet-method process for obtaining single high-purity rare earth in recovery is avoided, and advantageous conditions are provided for subsequently preparing neodymium iron boron regeneration magnetic powder.

Description

technical field [0001] The invention relates to a method for absorbing and co-precipitating neodymium iron from NdFeB oil sludge with ferric hydroxide colloid and recovering NdFeB oil sludge, which belongs to the technical field of recycling NdFeB oil sludge. Background technique [0002] Today, one out of every six new technologies is related to rare earths, which fully demonstrates the role and status of rare earths in new technologies. Rare earth is an important strategic resource in the 21st century and the "monosodium glutamate" of modern industry. The reason why rare earth elements are called "strategic elements in the 21st century" is because they have special physical and chemical properties that other elements do not have. Many new rare earth materials made based on these characteristics have excellent performance and are widely used, and are widely used in electronic information, communication technology, automobile manufacturing, energy, aerospace and other field...

AI Technical Summary

Problems solved by technology

[0006] Based on the above current rare earth recovery methods, although these processes can regain rare earths, there are still many problems: first of all, from the results, the circular chain of the above processes does not form a real cycle, and the products obtained by these processes are only Rare earth oxides, but not made into industrial products that can be used directly

Only in the extraction process, because of the need for a higher liquid-to-liquid ratio and better stripping effect, the acid consumption is more than 10 times the normal stoichiometric amount, and the acid-base waste liquid formed in these processes is very high at the end of the process. Difficult to handle; not only that, the sulfuric acid double salt precipitation method will produce SO which is very harmful to the human body in the process of iron recovery 2 and H 2 S gas

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