Zirconium sample container

Similar to the above-mentioned results, there is no diffraction peak of silica in all the samples. The pure zirconium oxide P-ZrOz-lS displays mainly the peaks of monoclinic ZrOz. However, tetragonal ZrOz is the dominant phase in the samples containing a certain amount of silica. Not... 

As follows from Fig. 2d, contrarily to the pure ceria sample, samples of mixed fluorite-like solid solutions retain molecular forms of oxygen (O2 [16]). The intensity of those bands is higher for samples containing calcium, fluorine and smaller amount of zirconium. It seems to correlate with the decreased ability of those systems to dissociate molecular oxygen due to a lower density of either highly unsaturated cations or clustered centers. 

Fig. 10 displays the SO2 weight loss evolution (mass 64) as a function of temperature for different Zr concentrations and S04 Zr ratio = 0.5. This figure shows that the SO2 peak shifts to higher temperature when the Zr concentration decreases. In the case of 0.025 molZr/L, the major sulfate loss occurs at 830 °C. This indicates that the sulfates linked to the pillars which give a dooi at 23.4 A develop the best thermal stability. However, for samples prepared with higher zirconium acetate concentration, the departure of sulfur occurs at lower temperatures. As those samples contain a polymeric phase, this Zr-SOa phase probably gives a less stable sulfate. 

Pitchblende is one of the most fertile sources of radioactive material. Its composition varies widely, but it always contains an oxide of uranium, associated with oxides of other metals, especially copper, silver, and bismuth the Austrian mineral contains cobalt and nickel the American, samples contain no cobalt or nickel but are largely associated with iron pyrites and arsenic zinc, manganese, and the rare earths are frequently present, while occasionally calcium, barium, aluminium, zirconium, thorium, columbium, and tantalum are reported. Dissolved gases, especially nitrogen and helium, are present in small proportions. 

This method is based on the bleaching action of fluoride ion content of the sample. The color of fhe red Zr-solochrome cyanine R (Aldrich Cat. No. 23,406-0, Sigma Prod. No. E2502) [52] complex fades as ZrOp2 is formed in the medium. As a matter of fact, no simple stoichiometric relationship exists between the fluoride and the zirconium complex with the dye. Therefore, in order to obfain reliable results, the reaction conditions need to be controlled very carefully. The absorbance of fhe reaction media is measured at 540 nm. The fluoride concenfrafion is evaluated using an absorbance-fluoride concentration calibration curve prepared with standard solutions. The method can be used for samples containing 0-2.5 pg fluoride. 

The chemical separation is based on combustion of the zirconium sample (1 g) in the presence of tungsten granules (20 g) and steel (0.5 g) containing 1.2 % carbon. The apparatus used is shown in Fig. II-45. 

Assay of beryUium metal and beryUium compounds is usuaUy accompHshed by titration. The sample is dissolved in sulfuric acid. Solution pH is adjusted to 8.5 using sodium hydroxide. The beryUium hydroxide precipitate is redissolved by addition of excess sodium fluoride. Liberated hydroxide is titrated with sulfuric acid. The beryUium content of the sample is calculated from the titration volume. Standards containing known beryUium concentrations must be analyzed along with the samples, as complexation of beryUium by fluoride is not quantitative. Titration rate and hold times ate critical therefore use of an automatic titrator is recommended. Other fluotide-complexing elements such as aluminum, sUicon, zirconium, hafnium, uranium, thorium, and rate earth elements must be absent, or must be corrected for if present in smaU amounts. Copper-beryUium and nickel—beryUium aUoys can be analyzed by titration if the beryUium is first separated from copper, nickel, and cobalt by ammonium hydroxide precipitation (15,16). 

TLC spectrophotometry is used to determine zirconium in Mg-Al alloy. For this purpose, the alloy sample (2 g) is dissolved in HNO3 (20 ml, 6 M), and zirconium is extracted in 6 ml of 0.02-M diantipyrilmethane (DAM) solution in chloroform. The extract was concentrated to 0.4 ml and an aliquot (10 p,l) was chromatographed on silica gel LS plate using 4-M HCl -f dimethylformamide (1 2) as the mobile phase. After development, the portion of the sorbent layer containing the zirconium-DAM complex was removed, and the metal was extracted with 6-M HCl. The zirconium present in this solution was determined in the form of a xylenol orange complex (Amax, 540 nm) by spectrophotometry [22]. 

Interpretation of the spectra in Fig. 4.6 is best done by comparison with those of zirconium ethoxide and zirconium oxide reference compounds. Figure 4.7 contains the ZrO+/Zr+ and ZrO/Zr+ ratios from the SIMS spectra of the reference compounds, and of the catalysts as a function of the calcination temperature. The figure clearly shows that catalysts calcined at temperatures up to 200 °C have ZrO+/Zr+ and Zr02+ /Zr+ ratios about equal to those measured from a zirconium ethoxide reference compound. However, samples calcined above 300 °C have intensity ratios close to that of Zr02. 

Hafnium is a ductile metal that looks and feels much hke stainless steel, but it is significantly heavier than steel. When freshly cut, metallic hafnium has a bright silvery shine. When the fresh surface is exposed to air, it rapidly forms a protective oxidized coating on its surface. Therefore, once oxidized, hafnium resists corrosion, as do most transition metals, when exposed to the air. Chemically and physically, hafnium is very similar to zirconium, which is located just above it in group 4 on the periodic table. In fact, they are so similar that it is almost impossible to secure a pure sample of either one without a small percentage of the other. Each will contain a small amount of the other metal after final refining. 

Fig. 4.13 Square-wave voltammograms of PIGEs modified with mixtures of a zirconium-containing sample plus Zr02 (standard) and ZnO (auxiliary reference material) in contact with O.IOM VaCZ. Sample ZnO mass ratio equal to 4.422 ZnO Zr02 mass ratio equal to (a) 0.163 (b) 1.216 and (c) 5.374. Potential scan initiated at —1.45 V in the positive direction without prior electrodeposition step. Potential step increment 4 mV square-wave amplitude 25 mV frequency 15 Hz. [234]...

Many [M(dik)4] complexes are volatile, especially those that contain fluorinated diketonate ligands. Mass spectra and gas chromatographic behavior of several of these complexes have been studied (see Table 10). Isenhour and coworkers240 241 have employed fluorinated diketonates in mass spectrometric procedures for determination of Zr and Zr/Hf ratios in geological samples. The most intense peak in mass spectra of [M(dik)4] complexes is [M(dik)3]+. Sievers et al.242 have used gas chromatography of metal trifluoroacetylacetonates to separate Zr from Al, Cr and Rh. However, attempts to separate [Zr(tfacac)4] and [Hf(tfacac)4] by gas chromatography were unsuccessful. Zirconium and hafnium can be separated by solvent extraction procedures that employ fluorinated diketones.105 [M(dik)4] (M = Zr or Hf dik = acac, dpm, tfacac or hfacac) have been used as volatile source materials for chemical vapor deposition of thin films of the metal oxides.243,244... 

The remaining studies reviewed in this section deal with binary oxides that contain titania. Shibata and Kiyoura (140) measured surface acidities by the n-butylamine titration method of the Ti02-Zr02 system as a function of composition and method of preparation. Samples were prepared by calcination of coprecipitated mixtures of titanium and zirconium hydroxides that were made by ammonia or urea addition. The products had... 

It was quite unexpectedly found that the amorphous samples of zirconium and hafnium alkoxides M(OR)4 contain several types of oxocomplexes, particularly, M3O(OR)i0 and M40(0R)14 [1612], The trinuclear Zr3([l3-0)()i3-OBu XOBu ), was isolated in a crystalline form and turned out to be a structural analog of the known isopropoxide clusters of Th, Mo, and U(IV) -MjOCOPr ),) [1520] (see also Sections 4.3 and 12.12). The inclusion of the solvent molecules inside the cavities of the structures and formation of alcohol solvates in many cases leads to microanalysis data that does not deviate much from those calculated for M(OR)n. 

The addition of zirconium to activated carbon may substantially increase the removal of arsenic from water (Daus, Wennrich and Weiss, 2004 Schmidt et al., 2008). (Daus, Wennrich and Weiss, 2004) used batch and column tests to evaluate the ability of five materials (activated carbon, zirconium-loaded activated carbon, zerovalent iron, granulated Fe(III) hydroxide, and a commercial product, Absorptionsmittel 3 ) to sorb As(III) and As(V) from water. The GAC had grain sizes between 1.0 and 1.5 mm. The material was primarily chosen as a comparison with the zirconium-loaded sample. The zirconium-loaded activated carbon contained 28 mg zirconium g 1 activated carbon and was produced by shaking activated carbon in a solution of zirconyl nitrate (Zr0(N03)2). The zerovalent iron (Fe(0)) primarily had particle sizes of 1.2-1.7 mm. Absorptionsmittel 3 is a mixture of calcite, brucite, fluorite, and iron hydroxides. The granular iron hydroxides consisted of mostly amorphous Fe(III) hydroxide coatings on sand grains (particle sizes of 3-4mm) (Daus, Wennrich and Weiss, 2004, 2950). 

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