A method for recovering rare earth and aluminum from ion adsorption type rare earth ore

Abstract

The invention discloses a method for recycling rare earth and aluminum from ion adsorption type rare earth ores. The method comprises the following steps: leaching the ion adsorption type rare earth ores by a leaching agent to obtain rare earth leachate; then adding at least one of magnesium chloride, sodium chloride and potassium chloride in the leachate; and controlling the chloride ion concentration, the temperature and the pH in a precipitation process of a calcium-alkali compound to achieve the purpose of increasing solubility of calcium sulfate and reduce generation of the calcium sulfate in the precipitation process. Meanwhile, under the related conditions of high salinity and the like, the migration speeds of rare earth ions and hydroxyl ions in a precipitation system of calcium oxide are reduced, the degree of supersaturation of rare earth hydrate is controlled effectively, and crystal precipitates of the rare earth hydrate is facilitated. By the method, ammonia nitrogen pollution is eliminated, the rare earth recycling rate is increased, and aluminum resources are recycled comprehensively. Meanwhile, formation of calcium sulfate in the precipitation process of the calcium oxide is reduced, the production cost is reduced, and meanwhile, the product with the qualified purity is obtained. An impurity removal process does not exist in the method, and therefore, loss of rare earth in the impurity removal process can be avoided.

Description

technical field [0001] The invention relates to the field of rare earth hydrometallurgy, in particular to a method for recovering rare earth and aluminum from ion-adsorption rare earth ores. Background technique [0002] Ion-adsorption rare earth ore is a new type of exogenous rare earth mineral, which was first discovered in Ganzhou, Jiangxi Province, my country in 1969, and is widely distributed in seven southern provinces including Jiangxi, Guangdong, Guangxi, Hunan, Fujian, Yunnan, and Zhejiang. This kind of minerals has a complete distribution of rare earths, low radioactivity, and is rich in medium and heavy rare earth elements. It is a valuable strategic mineral resource in my country. Its development and utilization enriches medium and heavy rare earth resources, and can solve the problem that traditional endogenous rare earth ores almost only produce light rare earths. [0003] In general, the full-phase rare earth grade in ion-adsorption rare earth ores is general...

AI Technical Summary

Problems solved by technology

In response to this problem, experts have also proposed related solutions (CN103436720, CN102190325, CN104152693), but they all have problems and cannot be implemented; CN101475202 uses calcium oxide or a mixture of calcium oxide and seed crystals as a precipitant to precipitate rare earth rare earths in solution

As for the calcium oxide precipitant, it is a slightly soluble substance, and the precipitation reaction is fast and the effect is good. However, there are sulfates in the leaching agent of the ion-adsorption rare earth ore, which causes a large amount of sulfate radicals to be contained in the leaching solution. Calcium oxide is used alone as the Precipitating agent, which will produce a large amount of calcium sulfate precipitation in the process of precipitating ion ore leachate, also greatly reduces the purity of rare earth concentrate products, and cannot obtain qualified products

At the same time, hydroxide precipitation has poor crystallization performance, resulting in poor filtration performance and low production efficiency.

[0005] In addition, the current leachate treatment adopts the method of removing impurities first and then precipitating. During the process of removing impurities, about 6% of rare earths will enter the removal residue, resulting in the loss of rare earths, and at the same time, aluminum resources will also be lost to varying degrees.

Images