Process for extracting rare-earth from sulfuric acid treating phosphorite process

Abstract

The invention provides a process for extracting rare earth from a sulfuric acid treating phosphorite process. In the process, a sulfuric acid refining process and a rare earth extracting process are combined, and the rare earth is reclaimed from low-concentrate sulfuric acid raffinate generated in a crude phosphoric acid extracting and refining process so as to realize reclamation of a rare-earth element. The process comprises the following steps of: (1) extracting the rare-earth element from the raffinate by adopting acidic or neutral extractant to obtain rare earth loaded organic phase and secondary raffinate; (2) washing the rare earth loaded organic phase and performing back extracting on the rare earth-loading organic phase by using acid to obtain rare earth strip liquor and blank organic phase; and (3) precipitating the rare earth strip liquor to obtain solid rare earth salt after pH value of the obtained rare earth strip liquor is adjusted, and calcining the strip liquor to obtain rare earth oxide. The process has the advantages of realizing reclamation of the rare-earth element, relatively easily extracting the rare earth, along with high rare earth extraction yield.

Description

technical field [0001] The invention relates to a process for extracting rare earths from sulfuric acid treatment of phosphate rock, in particular to a process for refining phosphoric acid and extracting rare earths from wet process phosphoric acid containing rare earths, belonging to the technical field of wet process phosphoric acid and rare earth smelting. Background technique [0002] Phosphoric acid is a basic industrial raw material with a wide range of uses. The annual output of phosphoric acid in the world is about 40 million tons. The production methods of phosphoric acid are divided into wet method and thermal method. The wet method has been paid more and more attention because of its low energy consumption and low requirements on ore grade. [0003] At present, the treatment methods of wet-process phosphoric acid are mainly hydrochloric acid method, nitric acid method and sulfuric acid method. Among them, sulfuric acid method is the most widely used in China becau...

AI Technical Summary

Problems solved by technology

[0005] In order to recover valuable element rare earths from crude phosphoric acid prepared by wet phosphoric acid process, some people also proposed to use organic extractant to directly extract rare earths from crude phosphoric acid, such as using a mixed extractant of P204 and TBP to directly react with crude phosphoric acid, Let rare earth and uranium enter the extraction agent to form an extract, and then back extract to obtain rare earth. However, due to the high total concentration of phosphoric acid in the crude phosphoric acid system, the extraction efficiency of rare earth is low, which brings great difficulties to the recovery of rare earth.