Method for recovering rare-earth waste material

Abstract

The invention relates to a method for recovering a rare-earth waste material. The method comprises the following steps of: (1) adding a decomposition auxiliary agent and fluxing agent powder into the rare-earth waste material, and evenly mixing to obtain mixed material, wherein the dosage of the decomposition auxiliary agent is 20-200wt% of the total weight of the rare-earth waste material, and the dosage of the fluxing agent powder is 1-20 wt% of the total weight of the rare-earth waste material; (2) roasting the mixed material obtained in the step (1) for 1-6 hours at the temperature of 600-1400 DEG C; (3) adding an acid solution into the roasted product obtained in the step (2) for acid dissolution, filtering and separating to obtain acid leaching liquor which mainly contains rare-earth elements and acid leaching residue; and (4) separating the rare-earth elements from other metal elements in the acid leaching liquor. The method provided by the invention realizes the cyclic utilization of the rare-earth waste material, is simple to operate, high in recovery rate of valuable elements in the waste material and low in reagent cost, saves energy, reduces emission and is low in environment harmfulness, and has important significance in the aspects of ecological protection and economic development promotion.

Description

technical field [0001] The invention belongs to the technical field of regeneration treatment of rare earth wastes, and in particular relates to a recovery method of rare earth wastes. Background technique [0002] Rare earth is an important strategic resource for my country's high-tech industry in international competition. my country is the world's largest consumer of rare earths, and due to production and use factors, a large amount of rare earth phosphors, ceramic powders, gemstone powders and other wastes are produced every year. Rare earth residues and waste materials are valuable renewable resources, and the recovery of rare earth elements from waste materials is beneficial to resource utilization and environmental protection, and is in line with national industrial policies. [0003] At present, the resource recovery of waste fluorescent lamps at home and abroad is basically still in its infancy, and most of the phosphors are treated as special waste landfills, with...

AI Technical Summary

Problems solved by technology

The red powder in the rare-earth three-color phosphor is easily soluble in acid, and can be recovered by direct acid dissolution, but the yield of direct acid dissolution is low, and only the yttrium and europium oxide that is easily soluble in acid can be recovered, resulting in The waste of aluminate rare earth resources that are insoluble in acid, such as the Chinese patent application "A preparation method for recovering high-purity yttrium and europium from phosphor waste" (application number 201010520143.7, publication number CN101985694A, publication date March 16, 2011 day) using hydrochloric acid dissolution process

[0024] Aiming at the recovery of other rare earth components that are insoluble in acid under normal temperature and pressure, the Chinese patent application "method for recovering rare earth oxides from phosphor powder and polishing powder waste" (application number 201010548951.4, publication number CN102115822A, publication date 2011 July 6) provided a method to recover rare earth components by dissolving rare earth oxides with sulfuric acid after roasting. This method can leach phosphates that are difficult to dissolve in acid at room temperature, but a large amount of acidic waste gas will be generated during the roasting process. Serious environmental pollution; Chinese patent application "a method for recovering rare earth elements in waste fluorescent lamps" (application number 200810029417.5, publication number CN101307391, publication date November 19, 2008) provides a method for recycling using hydrochloric acid dissolution after alkali roasting Rare earth components, this method is relatively cumbersome in operation, and the stable rare earth aluminate is roasted by alkali to obtain NaAlO which is soluble in water 2 , KAlO 2 , the product needs to be washed multiple times, and the aluminum in the phosphor powder is also washed into the washing water while the residual alkali is removed by water washing, and the rare earth can be extracted by acid leaching of the washed product, the overall process is long, the water consumption is large, and the loss of rare earth is increased; China The patent application "method for recovering rare earth metals from fluorescent lamps" (application number 200780020276.4, publication number CN101461024A, publication date June 17, 2009) provides a method of optimizing the combination of the above two, which not only increases the process flow , and the above problem still exists