Process for separating zirconium and hafnium by solvent extracting method

Abstract

The invention belongs to the field of wet metallurgy and the technical field of zirconium and hafnium separation, and in particular, relates to a process for separating zirconium and hafnium by a solvent extracting method. Industrial products containing hafnium zirconium chloride acetyl are used as raw materials for such procedures as water solution, alkali sinking, washing and nitric acid dissolving to prepare zirconium (hafnium) nitrate acetyl solution; TBP kerosene solution of adding phase modifying agent octanol is used as an extracting agent; most zirconium and less hafnium are extracted into an organic phase through multistage counter-current extraction by using the characteristic of TBP priority extraction of zirconium; the loaded organic phase is washed by nitric acid solution with a certain concentration to further remove most hafnium in the organic phase; the acid-washed loaded organic phase is reversely extracted by water to obtain zirconium nitrate acetyl solution; the solution is precipitated in ammonia, dried and calcined to obtain zirconium dioxide powder, and the mass of the zirconium dioxide powder accords with the atomic energy-level zirconium dioxide standard; less zirconium and most hafnium only remained in residual water phase of zirconium after reverse extraction are extracted; the content of zirconium in hafnium meets the requirements on impurity zirconium by atomic energy-level hafnium; and atomic energy-level hafnium can be directly prepared by enrichment.

Description

technical field [0001] The invention belongs to the technical field of separation of zirconium and hafnium in the field of hydrometallurgy, and in particular relates to a process for separating zirconium and hafnium by a solvent extraction method. Background technique [0002] Zirconium and hafnium are naturally symbiotic, and they belong to Group IVB elements in the periodic table of chemical elements. The atomic radii, ionic radii, and structures of the two are very similar, resulting in their chemical properties are also extremely similar, making them one of the most difficult to separate element pairs in the periodic table. At home and abroad, there are many studies on the separation methods of zirconium and hafnium, which are mainly divided into fire separation and wet separation. [0003] The fire separation successfully applied in industrial production is zirconium hafnium molten salt rectification method, which has the advantages of less consumption of chemical reag...

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Problems solved by technology

Among them, the MIBK-HCNS extraction method has low hafnium content in zirconium, large extraction capacity, basically closed process, and mature technology, but the consumption of chemicals is high, and it is easy to decompose to produce poisonous gas, and the solubility of MIBK in water is as high as 0.20%, so the loss is serious, and there is still sewage Emissions and other issues, so the law has gradually been phased out

The advantages of the TOA extraction method are small pollution, simple equipment, and low investment costs, but the extraction capacity of this method is small, the separation factor is not high, and it is difficult to obtain high-purity zirconium and atomic-level hafnium

Tributyl Phosphate (TBP-HCl-HNO 3 ) method has high separation factor, less reagent input, and large extraction capacity, but the extraction stock solution used in this method has high acidity and is a mixed acid, and the emulsification phenomenon is serious during the operation process, which makes the extraction operation difficult to carry out normally, and limits the popularization and application of this process.

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