The preparation of high-purity ammonium metavanadate from impure vanadium pentoxide by precipitation with ammonium chloride

1965 ◽  
Author(s):  
J A Vezina ◽  
W A Gow
Keyword(s):  
Ammonium Chloride ◽  
Vanadium Pentoxide ◽  
High Purity ◽  
Ammonium Metavanadate

Preparation and characterisation of vanadium pentoxide supported rhodium catalyst

1988 ◽  
Vol 46 ◽  
pp. 946-947
Author(s):  
A. Legrouri
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Physicochemical Properties ◽  
Surface Area ◽  
Vanadium Pentoxide ◽  
High Purity ◽  
Gas Adsorption ◽  
Rhodium Catalyst ◽  
Optical Methods ◽  
Reducible Oxides

The industrial importance of metal catalysts supported on reducible oxides has stimulated considerable interest during the last few years. This presentation reports on the study of the physicochemical properties of metallic rhodium supported on vanadium pentoxide (Rh/V2O5). Electron optical methods, in conjunction with other techniques, were used to characterise the catalyst before its use in the hydrogenolysis of butane; a reaction for which Rh metal is known to be among the most active catalysts.V2O5 powder was prepared by thermal decomposition of high purity ammonium metavanadate in air at 400 °C for 2 hours. Previous studies of the microstructure of this compound, by HREM, SEM and gas adsorption, showed it to be non— porous with a very low surface area of 6m2/g3. The metal loading of the catalyst used was lwt%Rh on V2Q5. It was prepared by wet impregnating the support with an aqueous solution of RhCI3.3H2O.

The nucleation kinetics of ammonium metavanadate precipitated by ammonium chloride

2016 ◽  
Vol 441 ◽  
pp. 117-123 ◽  
Author(s):  
Guangchao Du ◽  
Zhaohui Sun ◽  
Yong Xian ◽  
Han Jing ◽  
Haijun Chen ◽  
...  
Keyword(s):  
Ammonium Chloride ◽  
Ammonium Metavanadate ◽  
Nucleation Kinetics ◽  
Kinetics Of

A Novel Method to Prepare High-purity Vanadium Pentoxide by Chlorination with Anhydrous Aluminum Chloride

2017 ◽  
Vol 46 (5) ◽  
pp. 669-671
Author(s):  
Dan-dan Jiang ◽  
Hong-ling Zhang ◽  
Hong-bin Xu ◽  
Yi Zhang
Keyword(s):  
Vanadium Pentoxide ◽  
Aluminum Chloride ◽  
High Purity ◽  
Anhydrous Aluminum Chloride ◽  
Novel Method

Comparison between Vanadium Dioxides Produced by Ammonium Metavanadate and Vanadium Pentoxide

2011 ◽  
Vol 306-307 ◽  
pp. 234-237 ◽  
Author(s):  
Ji Qi ◽  
Chen Niu ◽  
Ying Mei Xu ◽  
Hua Hai ◽  
Lei Zou
Keyword(s):  
Phase Transition ◽  
Vanadium Pentoxide ◽  
Thermal Reduction ◽  
Ammonium Metavanadate ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Ammonia Gas ◽  
X Ray ◽  
Pentagonal Prism ◽  
Enthalpy Of Phase Transition

The facile processes were developed for synthesizing vanadium dioxide (VO2) by pyrolyzing ammonium metavanadate (NH4VO3) in nitrogen (N2) flow and by thermal reduction of vanadium pentoxide (V2O5) in ammonia gas. X-ray diffraction (XRD), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) were applied to analyzing the product VO2. The experimental results indicated that VO2microcrystal particles were successfully synthesized from both NH4VO3and V2O5. From NH4VO3the product VO2presents two kinds of micro morphologies, torispherical and pentagonal prism. The phase transition mainly takes place at 337.8K and 341.8K. The average enthalpy of phase transition is 28.82 J/g. From V2O5the product VO2presents rhombohedral. The phase transition temperature is approximately 342.6K and the enthalpy of phase transition is 44.90 J/g.

Assay of sodium in high-purity vanadium pentoxide by flame photometry

1965 ◽  
Vol 2 (5) ◽  
pp. 299-299
Author(s):  
V. L. Zolotavin ◽  
Yu. F. Bukreev ◽  
L. K. Tolstov ◽  
I. Ya. Bezrukov
Keyword(s):  
Vanadium Pentoxide ◽  
High Purity ◽  
Flame Photometry

Preparation of High-Purity Iron by Means of Ammonium Chloride Complexes

2018 ◽  
Vol 63 (6) ◽  
pp. 736-741
Author(s):  
A. N. D’yachenko ◽  
R. I. Kraidenko ◽  
A. A. Smorokov
Keyword(s):  
Ammonium Chloride ◽  
High Purity ◽  
Chloride Complexes ◽  
Purity Iron ◽  
High Purity Iron

Optimization on Response Surface Methodology for Preparing V2O5 from Industrial Ammonium Metavanadate

2014 ◽  
Vol 33 (2) ◽  
pp. 155-160 ◽  
Author(s):  
Yuxiang Chen ◽  
Bin Zhang ◽  
Shenghui Guo ◽  
Jinhui Peng ◽  
Lei Guo ◽  
...  
Keyword(s):  
Weight Loss ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Calcination Temperature ◽  
Vanadium Pentoxide ◽  
Layer Structure ◽  
Quadratic Equation ◽  
Equation Model ◽  
Ammonium Metavanadate ◽  
Calcination Time

AbstractIn order to obtain the vanadium pentoxide, the process of vanadium pentoxide preparation by calcination from industrial ammonium metavanadate was further investigated. The effects of calcination temperature and calcination time were studied. The conditions of technique to prepare vanadium pentoxide in flakes by calcination from industrial ammonium metavanadate were optimized using a central composite design of response surface methodology. A quadratic equation model for field was built and effects of main factors and their corresponding relationships were obtained. The statistical analysis of the results showed that in the range studied, the rate of weight loss of the industrial ammonium metavanadate was significantly affected by the calcination temperature and calcination time. The results showed that the optimum conditions of ammonium metavanadate calcination were as follows: sample mass 15 g, calcination temperature 900 °C, calcination time 2.4 h, the rate of weight loss 85.1%. In addition, the sample was characterized by XRD and SEM. The SEM analysis and XRD showed the product was layer structure. According to results from analysis of variance, the value of the determination coefficient (R2 = 0.9417) indicates that the model was a good fit that 94.17% of the variation could be explained well by the model.

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