Method of recovering rare earth and aluminum from weathered elution-deposited rare earth ores

Abstract

The invention discloses a method of recovering rare earth and aluminum from weathered elution-deposited rare earth ores. The method comprises the steps of leaching the weathered elution-deposited rare earth ores with a leaching agent to form rare earth leaching liquor, adding an assistant into the rare earth leaching liquor, and adding calcium oxide into the leaching liquor for precipitation. The concentration, temperature and pH (potential of hydrogen) of the assistant are controlled to achieve coordination of calcium ions and assistant molecules, so that the purpose of avoiding generating calcium sulfate is achieved; and the generating of calcium sulfate in a precipitation process is reduced. At the same time, the added assistant can return to be used for mineral leaching, exerts an effect of strengthening leaching under an acidic condition and increases a leaching rate of rare earth. No purification process is adopted in the method, and the loss of the rare earth in the purification process can be avoided. The method removes ammonia-nitrogen pollution, avoids the loss of the rare earth caused by the purification process of the traditional technology, increases a recovery rate of the rare earth, and comprehensively recovers an aluminum resource, and finally, a product with qualified purity is obtained.

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 weathering crust elution type rare earth ore. Background technique [0002] Weathering crust elution-type rare earth ore is a new type of exogenous rare earth mineral, which was first discovered in Ganzhou City, Jiangxi Province, my country in 1969. Such minerals are widely distributed in Jiangxi, Guangdong, Guangxi and other provinces in southern my country. They have a complete distribution of rare earths, low radioactivity, and are rich in medium and heavy rare earth elements. They are valuable strategic mineral resources in my country. The development and utilization of ionic rare earth ores can solve the problem that monazite, bastnaesite, and mixed rare earth ores almost only produce light rare earths but lack medium and heavy rare earths. Under normal circumstances, the grade of full-phase rare earths in weathe...

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Problems solved by technology

Aiming at this problem, experts have also put forward relevant solutions (CN103436720, CN102190325, CN104152693), but there are problems and they cannot be implemented

CN101475202 uses calcium oxide or a mixture of calcium oxide and seed crystals as a precipitating agent to precipitate rare earths in a rare earth solution. As for the calcium oxide precipitating agent, it is a slightly soluble substance, and the precipitation reaction is fast and the precipitation effect is good. Sulfate is contained in the leaching agent of accumulative rare earth ore, resulting in a large amount of sulfate radicals 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 the ionic ore leaching solution, which is also greatly reduced. The purity of rare earth concentrate products, can not get qualified products

[0004] 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.

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