Method for in-situ leaching of rare-earth ores from weathering crust elution-deposited rare earth ore

Abstract

The invention discloses a method for in-situ leaching of rare-earth ores from a weathering crust elution-deposited rare earth ore. The method comprises the following steps: holes are drilled in an ore body and drilled from a humus layer, a completely weathering layer to a half weathering layer of the ore body, a guide pipe with an opened upper part and an opened lower part is inserted into the holes and reaches the half weathering layer, and an ore leaching liquid is injected into the guide pipe; a diversion trench is formed in a bedrock to be used for guiding the rare earth leaching liquid into a liquid collecting reservoir; holes are distributed in a net shape along the ridge of the ore body, and the distance between every two holes is 2-3 m; a hopper is mounted at the upper end of the guide pipe, a fixing device is arranged on the guide pipe passing through the humus layer. The method has the advantages that the content of leached rare earth mother liquid impurities is reduced, the subsequent rare earth mother liquid treatment is facilitated, the geological hazards caused by the ore body landslide due to water swelling of clay minerals with high content of the humus layer are reduced, ammonium chloride can be used as a leaching agent, and under the premise of not increasing the impurity removal cost, the rare earth leaching rate is improved, and the selection range of the leaching agent is widened.

Description

technical field [0001] The invention belongs to the field of hydrometallurgy, and in particular relates to a method for in-situ leaching of rare earth mother liquor from weathering crust leaching type rare earth ore, which is used for extracting rare earth. Background technique [0002] Weathering crust leaching-type rare earth ores are widely distributed in six provinces of Jiangxi, Guangdong, Fujian, Guangxi, Yunnan and Hunan in southern my country. It is composed of rare earth-containing granite and volcanic rocks, which are chemically and biologically weathered, and the original rocks are weathered to form clay minerals such as kaolin, and rare earth minerals are weathered to form rare earth ions adsorbed on clay minerals to form weathering crust leaching type rare earth ore. In industry, ammonium sulfate is usually used as a leaching agent. Heap leaching or in-situ leaching is used to exchange rare earths into the solution through ion exchange. The rare earth solution i...

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Problems solved by technology

[0012] Ammonium sulfate is the most commonly used leaching agent. The advantage is that the product has high purity, but the obvious disadvantage is that the leach solution has poor permeability, the rare earth extraction rate is 70-85%, and the highest peak of the leach solution rare earth concentration is also low, causing the leach solution The rare earth concentration drags. Tail; ammonium chloride is used as the leaching solution, its rare earth leaching rate and effluent rate are significantly higher than ammonium sulfate, and the recovery rate of rare earth is generally 5-10% higher than that of ammonium sulfate leaching solution, but the leaching rate of impurities is much higher than that of ammonium sulfate , the application in production often leads to the product purity not meeting the requirements, and many mines do not use it

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