- منطقة بودونغ الجديدة ، شنغهاي ، الصين .
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In this work, the process described is the selective separation of hafnium from zirconium with D2EHPA in a hydrochloric acid medium. Liquid–liquid solvent extraction programs were investigated, including the effects of the amounts of D2EHPA and hydrochloric acid used, to obtain better conditions for the separation of hafnium and …
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Zirconium is an ideal material for nuclear reactors due to its low absorption cross-section for thermal neutrons, whereas the typically contained hafnium with strong neutron-absorption is very harmful for zirconium. This paper provides an overview of the processes for separating hafnium from zirconium. The separation processes are roughly classified …
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The separation of hafnium from zirconium is the key of the nuclear grade zirconium production. Most of the commercially used separation methods are hydrometallurgical routes, including fractional crystallization, methyl isobutyl ketone (MIBK) extraction and tributyl phosphate (TBP) extraction.
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At present, there are few researches on the extraction of hafnium by electrodeoxidation process. The extraction of hafnium metal by electrodeoxidation process is facing several important issues. The main problem is lower inherent conductivity of HfO 2, which results in the high energy consumption. The introduction of …
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The most important disadvantages of this technology are the large consumption of chemicals and low zirconium/hafnium separation factor. ... The results of this study shows that proposed mixture of TBP and Cyanex 923 can be used successfully in the Zr/Hf separation process without risk of third phase formation.
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Separation of zirconium and hafnium by solvent extraction using mixture of TBP and Cyanex 923 ... The results of this study shows that proposed mixture of TBP and Cyanex 923 can be used successfully in the Zr/Hf separation process without risk of third phase formation. Advantages of the new process over conventional TBP–HNO3 process are ...
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The equilibrium and kinetics of methyl isobutyl ketone (MIBK) extraction resin for adsorption and separation of zirconium and hafnium were studied under the different conditions of acidity, initial total concentrations of zirconium and hafnium and temperature.
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Hafnium impurities present in such Zr metal samples for nuclear applications must be less than 100 ppm [5]. In nuclear industry, the separation of Zr and Hf is carried out using solvent extraction process with Tributyl Phosphate (TBP). In this process 60% TBP in kerosene is used for extraction of Zr from 3 M nitric acid medium.
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The process of solvent extraction and separation between zirconium and hafnium under acid medium was carried out with mixing the aqueous solution and the organic phase. Batch contacts with phase ratio O/A = 2:1 were performed for 15 min and the aqueous phase was taken for analysis after phase separation.
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As an advanced membrane separation method, the application of IIMs in Hf–Zr separation and Hf enrichment may effectively improve the shortcomings of low hafnium resource recovery and poor selectivity of traditional membrane separation …
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In this work, the process described is the selective separation of hafnium from zirconium with D2EHPA in a hydrochloric acid medium. Liquid–liquid solvent extrac-tion programs were investigated, including the effects of the amounts of D2EHPA and hydrochloric acid used, to obtain better conditions for the separation of hafnium and zirconium.
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A new process for the separation of hafnium from zirconium has been developed. This process is based on the repeated reaction of the mixed tetrachloride vapors of zirconium and hafnium with alkali metal chloride salts in a solid form; hafnium tends to remain in the condensed phase while zirconium concentrates in the vapor phase. This process has …
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The separation of zirconium and hafnium isotopes from the early actinides and rare earth elements (REE) with Eichrom's Pb resin has been studied. Batch studies were performed to characterize the behavior of actinium, thorium, zirconium, hafnium, lutetium, and yttrium on Pb resin from HCl solutions (0.001 M to 11 M). The early …
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Abstract Membrane filtration equipment was used to evaluate zirconium and hafnium separation efficiency by a membrane separation process. High rejection of Zr and Hf species in aqueous solution were obtained with nanofiltration and ultrafiltration membranes. This high rejection could be explained by the formation of high molecular …
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A selective extraction and separation of zirconium by solvent extraction with 1-octanol is proposed. The process is based on the dissolution of the metal basic carbonates in hydrochloric acid in the presence of potassium fluoride, using 1 …
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However, it needs many stages of separation to approach the nuclear-quality product, and the hafnium-free zirconium compounds purified by this process always require some additional pyrometallurgical operations of calcination, chlorination, and the reduction with Kroll process to obtain the final zirconium metal product.
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The MIBK-HSCN system has a shorter separation process and consumes much less organic extractant than other systems because it preferentially extracts Hf (which typically has a relatively small proportion of components) from the aqueous phase. ... Jr.; Distin, P.A. Zirconium and hafnium separation without waste generation. CIM Bull. 1998, 91 ...
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Zirconium is an ideal material for nuclear reactors due to its low absorption cross-section for thermal neutrons, whereas the typically contained hafnium with strong neutron-absorption is very harmful for zirconium. This paper provides an overview of the processes for separating hafnium from zirconium. The separation processes are roughly classified …
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Nuclear grade zirconium and hafnium are important materials in nuclear power plants, which are usually produced with solvent extraction and separation technology. In this paper, the preferential extracting hafnium was successfully achieved by the selective complexation of the selected organic acids. Hydrochloric acid …
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