Vanadium distribution

Vanadium and chromium distributions (Figure 2) decrease toward low values in areas 2 and 3. The highest medians are found in area 4. The data show that vanadium is much more dispersed than chromium. Vanadium distribution also increases from north to south in Illinois. 

Catalyst Average pore diameter (relative scale) Vanadium distribution factor Nickel distribution factor ... 

Fig. 39. Nickel and vanadium distributions throughout aged catalysts from (a) top of bed and (b) bottom of bed (Oxenreiter et al., 1972).

The exclusion of asphaltenes is matched by the distribution of nickel inside and outside the catalyst pore structure. Vanadium distribution is inconsistent, probably influenced by coke deposition at the higher temperatures. 

In order to empirically remove the effects of age, as determined by the nickel concentration, from the vanadium distribution, a regression of the data was performed to determine a best fit functional form relating vanadium with nickel. With the forced use of a zero intercept, for this case (and several others, not shown) best results were obtained for functions of the type ... 

Searching for the next most critical determinant of the vanadium distribution revealed a relationship between vanadium and the quantity of zeolite in each particle, as measured using the La+Ce intensity value. 

Soares, S.S., H. Martins, and M. Aureliano. 2006. Vanadium distribution following decavanadate administration. Arch. Environ. Contam. Toxicol. 50 60-4. 

The V and Ni images show that the left particle has been in the unit for a long time while the right particle is very new. In the older particle, the vanadium distribution is nearly homogeneous while the new particle shows vanadium diffusing from the external surface. This observation shows that vanadyl as well as nickel porphyrins must crack on the external catalyst skin. Vanadium migration then occurs after the metal deposit is on the catalyst surface. The Ni distribution confirms the age of the pair, but also reveals that edge enhancement persists on very old particles. This confirms that the deposited nickel has very little or no mobility in the FCC unit. 

Figure 4. Vanadium distribution in the lower part of the lithologic sequence including underclay, the Kinneman Creek lignite, and directly overlying clay and mudstone.

Vanadium concentrations on the spent catalysts, presented in Table n, show that the large unimodal pore Catalyst (Q) has accumulated more vanadium than the others. This is consistent with the highest HDM activity of this catalyst (19). Furthermore, the vanadium distribution within the pellet is more uniform for this catalyst than the others (Figure 4). For the narrow pore unimodal Catalyst (P), the vanadium concentration near the outer edge of the pellet is substantially higher than that near the center. Similarly among the bimodal pore catalysts, a more uniform distribution of the... 

D. Vanadium Distribution and Stabilization Key Words and Abbreviations References... 

D. Vanadium Distribution and Stabiuzation 1. Vanadium Distribution in Tunicate Blood Cells... 

Figure 8. Vanadium distribution in Meade Peak (left) and Retort (right) Members of the Phosphoria Formation shown by isograms, in parts per million.

Figure 4. The thermal stability of vanadium- and chromium- containing silica. 1,2,3 -are specific surface area dependencies on temperature of annealing of initial (1), vanadium (2) and chromium (3) containing silica gels. 4,5 - are temperature dependencies of Cr(+6) and Cr(+3) content 6,7 - are the temperature infiuence on the surface/bulk vanadium distribution.

Hansen TV, Aaseth J, Alexander J. 1982. The effect of chelating agents on vanadium distribution in the rat body and on uptake by human erythrocytes. Arch Toxicol 50 195-202. 

Box 5.3 I Nickel and vanadium distributions and sedimentary redox conditions... 

Figure 64 Vanadium distribution on spent catalyst particles/ ...

In 2003, Dajda et al. used multinuclear Si, and Zr SSNMR experiments to probe the vanadium distribution in vanadium-doped zircon [44], as previous studies had provided conflicting information on doping site preferences. Although it was understood that V ions were responsible for the blue color in V-doped zircon, the authors specifically sought to... 

Vanadium Distribution Between Blast Furnace Slag and Hot Metal... 

Keywords vanadium, distribution ratio, blast furnace, hearth of blast furnace... 

Vanadium distribution ratio was rearranged as the common form shown in equation (2) after thermodynamic calculation in order to be discussed conveniently. 

Figure 2 shows the effect of Ti02 content in slag on the vanadium distribution between hot metal and slag. It can be seen that both the vanadium distribution ratio and the equilibrium reaction rate will be decreased with increasing Ti02 content in slag. 

Figure 2. Effect of Ti02 content in slag on vanadium distribution (T=1703K) (a) Effect of Ti02 content in slag on vanadium distribution ratio (b) Effect of Xi02 content in slag on vanadium reduction rate...

Figure 3. Effect of binary basicity on vanadium distribution (T=1703K)...

Vanadium distribution ratio is increased due to double functions of lime. Firstly, V2O3 can be reduced by silicon in the hot metal as shown in equation (4)... 

Ti02 will react with lime and form perovskite, in this case, the forming of Ti(C, N) as shown in equation (3) will be prevented. Thus, a higher binary basicity is favorable for the vanadium diffusion and helpful for increasing vanadium distribution. 

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