Zirconium molybdate

Zirconium Molybdate, ZrfMoOjlj.ilHjO, is obtained by precipitation of ammonium paramolybdatc- solution with zirconium sulphate. ... 

Campbell, M. H. Quantitative Separation for Magnesium, Calcium, and Strontium Using Zirconium Molybdate Ion. Analytic. Chem. 37, 252 (1965). 

In nitric acid solution containing uranium, plutonium, zirconium, molybdenum and other fission products, precipitation of zirconium molybdate occurs preferentially. Solutions containing only zirconium and molybdenum yield the "same" precipitated mater-... 

The precipitation of the zirconium-molybdenum material is a function of acid strength, temperature and time. The rate of precipitation is lower with lower temperatures, low zirconium concentrations and higher acid strengths. There also appears to be an induction period before the onset of precipitation. Discussed here is the characterization of the zirconium molybdate solids, as obtained separately from nitric acid solutions chemical analyses, thermogravimetry and X-ray powder diffraction were used to characterize these solids. 

In the absence of zirconium, a plutonium-molybdenum compound can be precipitated from nitric acid solutions. The presence of zirconium in the same solution is detrimental to formation of this material, as zirconium molybdate is formed preferentially. However, the amount of Pu molybdate solids that form is a function of hydrogen ion concentrations at 1M HN03 or less, solids form but at higher acid concentrations the quantity of precipitate decreases. At 3M HN03 solids are just barely detectable. 

Usami, T. Tsukada, T. Inoue, T. Moriya, N. Hamada, T. Purroy, D. S. Malmbeck, R. Glatz, J. P. (2010). Formation of Zirconium Molybdate Sludge from an Irradiated Fuel and Its Dissolution into Mixture of Nitric Acid and Hydrogen Peroxide. Journal of Nuclear Materials, Vol. 402, No. 2-3, (July 2010), pp. 130-135, ISSN 0022-3115... 

In this process, catalysts, such as boric acid, molybdenum oxide, zirconium, and titanium tetrachloride or ammonium molybdate, are used to accelerate the reaction. The synthesis is either carried out in a solvent (aUphatic hydrocarbon, trichlorobenzene, quinoline, pyridine, glycols, or alcohols) at approximately 200°C or without a solvent at 300°C (51,52). 

Determination of phosphate as ammonium molybdophosphate. This may be readily effected by precipitation with excess of ammonium molybdate in warm nitric acid solution arsenic, vanadium, titanium, zirconium, silica and excessive amounts of ammonium salts interfere. The yellow precipitate obtained may be weighed as either ammonium molybdophosphate, (NH4)3[PMo12O40], after drying at 200-400 °C, or as P205,24Mo03, after heating at 800-825 °C for about 30 minutes. 

Fluoride, in the absence of interfering anions (including phosphate, molybdate, citrate, and tartrate) and interfering cations (including cadmium, tin, strontium, iron, and particularly zirconium, cobalt, lead, nickel, zinc, copper, and aluminium), may be determined with thorium chloranilate in aqueous 2-methoxyethanol at pH 4.5 the absorbance is measured at 540 nm or, for small concentrations 0-2.0 mg L 1 at 330 nm. 

The reagent can be used, for example, on aluminium oxide, silica gel, kieselguhr. Si 50000, RP and cellulose layers. Sodium molybdate-impregnated phases and zirconium oxide layers are also suitable [1]. 

Molybdates react very violently with zirconium. Detonations were mentioned during these reactions. 

Otherwise, the effect of uranyl or zirconium nitrates and molybdic acid on nitro and carbonyl compounds was negligible (27), while the presence of palladium reduced the yield of nitro derivative but caused an increase of the yield of carbonyl compounds (27). 

Syntheses of MPc from phthalodinitrile or phthalic anhydride in the presence of urea are the two most important laboratory and industrial methods. They were also used originally by Linstead et al. [8,9], This procedure allows the production of many phthalocyanine compounds [35-37], Catalysts such as boric acid, molybdenum oxide, zirconium and titanium tetrachloride, or ammonium molybdate are used to accelerate the reaction and improve the yield [36,37], Ammonium molybdate is especially effective. Reaction is carried out either in a solvent or by heating the solid components. When metal chlorides and phthalodinitrile are used as starting materials, the reaction products are partially chlorinated (e.g.,7). 

Zirconium phosphate, tungstate and molybdate, ammonium molybdophosphate and tungstophos-phate, hydrous oxides... 

Several inorganic ion exchangers like the zirconium salts of phosphates, silicate phosphates, molybdate phosphates, and tungstate phosphates showed selective sorption properties for potassium dissolved in sea water and brines. The potassium capacity of zirconium phosphate was found to be 25 mg K+/g. The selectivity for potassium increased with higher drying temperatures of the exchangers. The potassium ion sorption rate exceeded that of other cations40). 

The plutonium-bearing precipitate obtained from nitric acid solutions (containing molybdenum, zirconium and plutonium) gives an X-ray powder diffraction pattern not distinguishable from that of ZrMo207(0H)2(H20)2 precipitated without plutonium. However, since the Pu content is low, the Pu could be present either in the Pu molybdate structure or replacing Zr in the Zr molybdate structure and not be detected in the X-ray patterns. 

Zirconium can be determined as a ternary complex Zr-Mo-Arsenazo El formed in the presence of an excess of molybdate at pH 3.1 (e = 6.4-10" at 658 nm). The above-mentioned complex has also been used in the method based on the 4" order absorption spectrum, which gives a considerable increase of sensitivity [60]. 

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