A method for extracting rare earth from rare earth phosphor waste and fluorine-containing rare earth electrolysis waste

Abstract

The invention provides a method for extracting rare earth from rare earth phosphors wastes and fluorine-containing rare earth electrolysis waste residues. The method comprises the steps of firstly roasting after mixing the rare earth phosphors wastes, the fluorine-containing rare earth electrolysis waste residues and alkali; and carrying out water washing on an obtained roasted material, carryingout acid dissolution on filter residues after solid-liquid separation, using an alkali liquor for adjusting a pH value of an obtained acid dissolution liquid, and carrying out solid-liquid separationto obtain a feed liquid of rare earth ions. According to the method provided by the invention, during a roasting process, glass dust in the rare earth phosphors wastes is reacted with fluoride in thefluorine-containing rare earth electrolysis waste residues, so that silicic acid rare-earth salt is generated, fluorine transformation is promoted, and the dosage of the alkali is further reduced; thealkali damages a material structure in fluorescent powder at high temperature so as to generate rare earth oxide, meta-aluminate and the like; and water washing is combined to dissolve the meta-aluminate, fluoride salt and the like in water, so that the rare earth is extracted helpfully. A result of the embodiment shows that the leaching efficiency of rare earth elements achieves more than 98.5 percent, and the energy consumption is remarkably reduced.

Description

technical field [0001] The invention belongs to the technical field of resource recycling, and in particular relates to a method for extracting rare earth from rare earth fluorescent powder waste and fluorine-containing rare earth electrolytic waste residue. Background technique [0002] Rare earth is an important strategic resource of the country, and the recovery of rare earth from rare earth waste is of great significance to improve the utilization rate of rare earth resources and the sustainable development of rare earth industry. Commonly used waste materials for rare earth recovery and reuse in the prior art include fluorine-containing rare earth electrolytic waste and waste luminescent materials. [0003] As an important luminescent material, rare earth phosphors are widely used in products such as plasma TVs, semiconductor lighting LEDs, rare earth fluorescent lamps, mobile phones and computers. These products are eventually discarded by consumers in the form of sol...

AI Technical Summary

Problems solved by technology

However, in the rare earth recovery process of these two methods, the leaching rate of rare earth elements is not high, and the leaching rate is far from reaching 80%.

[0006] Common methods for recovering rare earth elements from fluorine-containing rare earth electrolytic waste mainly include concentrated sulfuric acid high-temperature burning method and alkali burning method, both of which have the problems of low rare earth leaching rate, single treatment object, and high comprehensive energy consumption.

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