Treatment method for fluorine-contained rare-earth mineral grains

Abstract

The invention discloses a treatment method for fluorine-contained rare-earth mineral grains. The treatment method comprises the following steps of (1) mixing first fluorine-contained rare-earth mineral grains with a first sulfuric acid solution by weight ratio of (2-10) to 1 of sulfuric acid to the first fluorine-contained rare-earth mineral grains, then, performing heating and heat preservation for performing solid-liquid reaction, and condensing and absorbing steam by a tail gas system, wherein the sulfuric acid concentration of the first sulfuric acid solution is 40 to 85 wt%; (2) after thereaction is ended, performing solid-liquid separation to obtain acid filtrate and acid filter residues; (3) leaching the acid filter residues with water to obtain rare earth sulfate water extract andliquid leached residues; and (4) supplementing a second sulfuric acid solution into the acid filtrate so as to enable the sulfuric acid concentration of the acid filtrate to be 40 to 85 wt%; circularly treating the first fluorine-contained rare-earth mineral grains according to the steps (1) to (3). According to the method disclosed by the invention, rapid decomposition of the fluorine-containedrare-earth mineral grains is realized, the reaction is easy to control, and meanwhile, cyclic utilization of a spent acid resource is realized.

Description

technical field [0001] The invention relates to a processing method for fluorine-containing rare earth mineral particles, in particular to a processing method for bastnaesite-containing rare earth mineral particles. Background technique [0002] Rare earth minerals mainly exist in the form of bastnaesite, mixed rare earth concentrate (bastnaesite and monazite), seaside placer (monazite), and weathering crust leaching type rare earth ore. Bastnaesite is represented by the Mountain Pass Mine in the United States, the Mianning Rare Earth Mine in Sichuan, China, and the Weishan Lake Mine in Shandong. The typical representative of mixed rare earth minerals is the Baiyun Obo rare earth minerals in the Baotou area of ​​Inner Mongolia. Therefore, it is of great significance to study the smelting and separation technology of bastnaesite minerals. At present, the smelting technology of bastnaesite in bastnaesite or mixed rare earth minerals has received more and more attention. [0...

AI Technical Summary

Problems solved by technology

The problem with the above scheme is that fluorine resources are not effectively utilized, and the extraction of rare earth resources is not thorough

The problem with the above scheme is that the bastnaesite concentrate needs to be oxidized and roasted at high temperature, and the steps are too cumbersome

However, the above scheme still has the following problems: first, it is difficult to control the end point of the solid-solid phase reaction in the reaction process, and the decomposition rate of rare earth minerals must be guaranteed by recycling undecomposed minerals; The reaction is terminated, and the water immersion impurity removal process needs to consume a large amount of neutralizing agent, and at the same time cause waste of sulfuric acid

The above scheme still has the following problems: one is that the concentration of sulfuric acid is too high, concentrated sulfuric acid and bastnaesite react violently through mixing, the reaction rate changes greatly, and the reaction is difficult to control; the other is that the rare earth material containing fluorine is mixed with sulfuric acid to form a semi-dry state , sulfuric acid is not easy to recycle; third, it can only process activated bastnaesite after roasting or other reactions, and cannot process unactivated bastnaesite or mixed rare earth concentrate