Process for extracting rare earth from phosphate concentrate

Abstract

The invention belongs to the field of rare earth metallurgy, and particularly relates to a full-flow process for extracting a rare earth element from rare earth-containing phosphate concentrate. According to the process, phosphate containing 0.05-0.3 percent of REO (Rare Earth Oxide) is used as a raw material, and decomposition is performed once by using low-concentration hydrochloric acid, so that most of impurities in the phosphate concentrate enter solution and the decomposition of the rare earth is effectively suppressed; primary residue is decomposed by using nitric acid, so that valuable metals such as rare earth enter the solution and secondary decomposition solution which meets a subsequent extraction process is prepared; and rare earth extraction is directly performed in a high-acid phosphate secondary decomposition solution system with complex impurity components by using a neutral extraction agent without adding a salting-out agent, and the rare earth is separated in one step under assistance of a washing measure to further separate phosphorus from the rare earth. The purity of the prepared rare earth enrichment is greater than 90 percent and the total rare earth recovery rate is over 90 percent.

Description

technical field [0001] The invention belongs to the field of rare earth metallurgy, and in particular relates to a whole process process for extracting rare earth elements from phosphorus concentrate containing rare earth. Background technique [0002] Many phosphate rocks contain rare earth elements, and rare earth elements are mixed into calcium fluorophosphate or calcium phosphate minerals in the form of isomorphism instead of calcium. Due to the low grade of rare earth, only about 0.1%-0.2% (according to REO), and it exists in mineral phase, it is a worldwide problem to extract rare earth elements from phosphorous concentrate. However, rare earth reserves in phosphate concentrate are large, and the distribution of rare earth elements is good. For example, the distribution of rare earth in Zhijin phosphate rock in Guizhou is medium-yttrium-rich and europium-rich, with reserves reaching 1.8 million tons, which exceeds the weathering crust leaching type in the five province...

AI Technical Summary

Problems solved by technology

This process has the following technical defects: (1) The extraction process needs to be acid-adjusted to adjust the pH value to a specified range to obtain a satisfactory extraction rate; (2) In order to improve the extraction effect of rare earths in the neutral extraction system, A large amount of salting-out agent needs to be added; (3) The extraction efficiency is low, and the extraction and separation effect on impurity ions is not ideal