Method for directly preparing cerium fluoride by extraction and separation

Abstract

The invention relates to a method for directly preparing cerium fluoride by extraction and separation, which comprises the following steps: 1) taking a sulphuric acid rare earth solution containing quadravalence cerium and fluorine or a nitric acid rare earth solution as a raw material, using a P507 organic solvent extractant for extraction and separation to obtain organic phase loading quadravalence cerium and fluorine; 2) using a stripping liquid prepared by inorganic acid and a reducing agent for stripping the loaded organic phase obtained in the step 1), reducing the Ce<4+> ion in the loaded organic phase by a reducing substance in the stripping liquid to Ce<3+> ion, combining with fluorine in the loaded organic phase to form cerium fluoride deposition and then enters in water phase, filtering to obtain the cerium fluoride powder. The method for directly preparing cerium fluoride by extraction and separation has the advantages that quadravalence cerium and fluorine in the organic phase are stripped by a cerium fluoride deposition mode to water phase during the rare earth extraction separation process, according to the invention, the separation, purification and material preparation are combined, so that cerium fluoride deposition preparation process can be omitted, the technology flow can be shortened, the powder material with controllable granularity and uniform particle size distribution can be obtained. The preparation cost is low, fluorine in ore can be effectively recovered and used, and the original auxiliary material consumption and production cost can be reduced.

Description

technical field [0001] The invention relates to a method for directly preparing cerium fluoride in an extraction process. Specifically, a rare earth sulfate solution or a rare earth nitrate solution containing tetravalent cerium and fluoride ions is used as a raw material, and P507 is used for extraction and separation to obtain tetravalent cerium and fluoride ion. The organic phase is directly stripped to prepare cerium fluoride, and the invention belongs to the field of rare earth separation and material preparation. Background technique [0002] As a high-tech element, rare earth is widely used in the field of materials and is known as a treasure house of new materials. Cerium fluoride is not only a new material, but also can be used as a raw material for new materials. Cerium fluoride is an important raw material for the preparation of single metal element cerium. At the same time, this compound is also widely used in other industrial fields such as polishing powder and ...

AI Technical Summary

Problems solved by technology

[0003] At present, the preparation method of cerium fluoride in industry is mainly to add fluorine-containing precipitant to the cerium-containing solution obtained by extraction, separation and purification to obtain cerium fluoride precipitation, and then obtain the product through steps such as filtration, washing, and drying. It is difficult to control the particle size distribution of the product cerium fluoride, and a large amount of raw and auxiliary materials need to be used in the preparation process, resulting in a large amount of wastewater discharge

[0004] Invention patent CN200710056173.5 proposes a method using a mixed extraction system to separate cerium to recover fluorine and prepare cerium trifluoride ultrafine powder. The patent uses a mixed extraction agent to extract cerium and fluorine from bastnaesite feed liquid Finally, it is directly precipitated by reduction and back extraction. This patent is suitable for the preparation of small particle size cerium fluoride, but it leads to poor settling performance and filtration performance of cerium fluoride slurry, and it is easy to form three-phase substances during the extraction process, resulting in subsequent treatment. The process is complicated, especially some small-sized cerium fluoride is entrained in the organic phase, which brings troubles to the organic recycling, and this patent needs to use a mixed extractant, because the neutral phosphorus extractant used in it is expensive, resulting in preparation Disadvantages such as complex process, low resource utilization, and high cost