Weathering crust illuviation-type rare-earth ore leaching agent and method for extracting rare earths by using same

Abstract

The invention provides a weathering crust illuviation-type rare-earth ore leaching agent and a method for extracting rare earths by using the same, particularly a leaching agent solution for weathering crust illuviation-type rare-earth ores. The active component is citrate, wherein the citrate is any one of ammonium citrate, sodium citrate, potassium citrate and magnesium citrate, or mixture of sodium citrate, potassium citrate and magnesium citrate. The method for extracting rare earths from weathering crust illuviation-type rare-earth ores comprises the following steps: leaching by using the citrate as the active component of the leaching agent to obtain a rare-earth leaching mother solution, removing impurities, and adding a precipitant to obtain a rare-earth enriched substance. In the weathering crust illuviation-type rare-earth extraction process, cation exchange interaction and anion (citrate ion) complex action exist, and the two actions can cooperate to enhance the rare-earth recovery rate and lower the concentration and consumption of the leaching agent.

Description

technical field [0001] The invention belongs to the field of hydrometallurgy, and in particular relates to a weathering crust leaching type rare earth ore leaching agent and a method for extracting rare earth. Background technique [0002] The weathering crust elution-type rare earth ore is a special rare earth mineral with a high proportion of medium and heavy rare earth, and it is a strategic mineral for national development. The rare earth elements in the weathering crust leaching type rare earth ores are mainly adsorbed on the clay minerals in the form of hydrated or hydroxyl hydrated ions, and the rare earth grade is low, only 0.05-0.3%. The ore particle size is extremely fine, and more than 50% of the rare earths are stored in the -0.78mm particle size with a yield of 24-32%. Conventional physical beneficiation cannot enrich rare earths into corresponding rare earth concentrates, so chemical leaching can only be used technology. [0003] When the weathering crust elu...

AI Technical Summary

Problems solved by technology

At present, the commonly used leaching agent is generally 1-4% ammonium sulfate, which has a high recovery rate of rare earths, but it is less produced in the south, and the demand for rare earth beneficiation is very large, so the supply is often in short supply.