Zirconium distribution ratios

Fig. 21.13 Sorption of tracer concentrations of actinides and lanthanides on amorphous zirconium phosphate of phosphate/zirconium ratio of 1.34 [196]. The distribution ratio ZrPyCff (aq) is plotted as a function of the rdtric acid concentration, C. Temperature 15°C. 

Figure 10.14 Comparison of measured and modelled (solid line) distribution ratio of zirconium from the study of Nazarenko and Mandzhgaladze (1969) as a function...

Brindley and Sempels (1), Vaughan et al. (2) and Shabtai (3) have shown that the experimental conditions of Al intercalation influences the physicochemical properties of the clay. The nature, amount and spacial distribution of the pillars change the thermal stability, texture and acidity of the pillared clays. For example, Rausch and Bale (4) have reported that the OH/Al ratio modifies the structure of the Al complex and that monomeric [Al(0H)x(H20)6-x] " or polymeric [A1i304(0H)24(H20)i2] species can be obtained. Clearfield (5) demonstrated that the polymerisation state of Zr species depends on the temperature, concentration and pH of the solutions. In any case, the height of pillars is largely controlled by the polymerisation state of the intercalated complexes. However, in order to maintain the accessibility of the inner surface, the density or spacial distribution of the pillars has to be controlled. This parameter has been studied by Flee et al (5), and Shabtai et al (7) for Al pillared clays and Farfan-Torres et al (8) for zirconium. 

Nanosized crystalline spheres of zirconia (Zr02) ranging from 2.5 to 15 nm in mean diameter with a narrow size distribution have been prepared by a method similar to that for the preparation of the uniform anatase titania (34). In a typical system, zirconium(IV) n-propoxide is mixed with triethanolamine at a molar ratio of 1 3 in a dry box filled with dry air to form a stable compound of Zi against the rapid... 

Group 4 elemental profiles in the ocean are shown in Fig. 12.6. Titanium (Ti), zirconium (Zr) and hafnium (Hf) exhibit substantial covariance in their distributions, and the correspondence between Zr and Hf is particularly close. In the Atlantic Ocean, Zr/Hf concentration ratios (Godfrey et at., 1996) generally range between 170 and 240. 

Zirconium recovery Distribution coefficients, assumed to be constant for all stages Zirconium Hafnium Flow ratio Required... 

It evidences that the Ti/Zr atomic ratio is constant through the whole sputtered layer and very close to the expected nominal value (i.e. 10). This finding demonstrates a good degree of compositional homogeneity of the prepared sample and an even distribution of the guest zirconium species in the host titania matrix. 

Single-site ethylene polymerization catalysts based on titanium or zirconium as the active center are primarily used in the low-pressure manufacture of polyethylene with a relatively very narrow molecular weight distribution to include high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE) and very low density LLDPE to include amorphous material. Table 4.1 summarizes a few examples of end-use applications for this type of polyethylene in terms of the density, molecular weight distribution and molecular weight for various applications. Note that in Table 4.1 a Melt Flow Ratio (MFR) value of 16 approximately corresponds to an polydispersity value of 2.0, which is indicative of a... 

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