Method for recovering thorium and rare earth from waste residue leachate

Abstract

The invention relates to the field of rare earth ore radioactive waste residue recovery, and discloses a method for recovering thorium and rare earth from a waste residue leachate. The method comprises the following steps that unsaponified CA-12 is added into the waste residue leachate to extract thorium to obtain a first organic phase and a first feed liquid, inorganic acid is added into the first organic phase to perform reverse extraction to obtain a CA-12 and a thorium solution, alkali is added into the thorium solution to adjust the acidity of the thorium solution to hydrolyze and precipitate the thorium to obtain Th(OH)4; and impurities are removed from the first feed liquid, a saponified CA-12 is added to extract lanthanide elements to obtain a second feed liquid and a second organic phase, and then the second feed liquid is precipitated the second organic phased is eluted correspondingly to complete recovery and enrichment of rare earth elements. The unsaponified CA-12 has veryhigh selectivity for extracting thorium from a mixed solution, thorium in the ionic rare earth ore radioactive waste residues is separated out through the unsaponified CA-12, the lanthanide elementsare extracted through the saponified CA-12, yttrium is precipitated through calcium hydroxide, and thorium and rare earth recovery and enrichment are completed.

Description

technical field [0001] The invention relates to the field of recovery of rare earth ore radioactive waste residue, and in particular provides a method for recovering thorium and rare earth from waste residue leachate. Background technique [0002] Ionic rare earth ores have the advantages of complete distribution of rare earth elements and easy mining, and have made great contributions to the development of the world's rare earth industry and the application of rare earths in high-tech fields. However, during the mining, smelting and rare earth separation of ionic rare earth ores, radioactive elements (thorium, uranium, radium, mainly thorium) will be transferred, enriched and diffused. In production practice, in order to reduce the influence of radioactive elements and impurities, it will be transferred to the slag as much as possible in the process of impurity removal, acid dissolution, wastewater neutralization, etc., resulting in the removal of impurities containing radi...

AI Technical Summary

Problems solved by technology

At present, since there is no clear way out for these waste residues, they can only be stored in the slag warehouses built by rare earth smelting and separation enterprises. The storage capacity of many slag warehouses is close to saturation, and their ability to resist natural disasters is weak, posing safety hazards.

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