Oxide slurries comparison

Three process schemes for H2S removal were evaluated to determine the lowest cost approach (1) an amine unit equipped with an incinerator, (2) a metal oxide slurry process, and (3) the LO-CAT process. A comparison of the projected capital and operating costs is summarized in Table 9-17 (Price et al., 1986). These cost data are in 1986 dollars and are based on 5 MMscfd of gas with an H2S concentration of 770 ppmv. 

Taking the slurry containing 6 wt % Si02 particles with a diameter of 30 nm, 1 wt % oxidizer and 2 wt % lubricant at pH 1.8 as an example, the surface features of the disk substrates polished in the slurry are shown in Table 4. For comparison, another kind of Si02 slurries with different particle size was conducted under the same conditions. The surfaces after polish with different slurries have different features. Ra and Wa decrease largely after polish in both slurries. Especially, the slurry with small particles exhibits lower Ra, Wa, but also lower MRR [ 108]. 

In 1999, Zhou and Clennan [24] reported the first examples of intrazeolite type I/ivOi reactions of organosulfides. Photo-oxidation of pentamethylene sulfide, 12, in NaMB Y in hexane slurry resulted in the formation of both the sulfoxide and sulfone. However, the sensitivity of the sulfone, I2SO2, sulfoxide, 12SO, ratio to the concentration of 12 was dramatically enhanced in the zeolite in comparison to homogeneous media. The percentage yield of the sulfoxide increased from 46% to nearly 90% in the zeolite and it remained essentially constant in... 

Fig. 12. Comparison of pot life for commercial available tungsten slurries with HjOj (diamonds), Fe(N03)3 (triangles), and HjIOs (squares) oxidizers (a) linear and (b) log scales.

FIGURE 5.24 MRR comparison of oxide wafer polishing on particle-containing pad with DI water and on IC1400 pad with fumed silica slurry at pH = 10.8 [81]. 

Ferric nitrate has also been used widely as an oxidizer in W CMP slurries. As a matter of fact, ferric nitrate based slurry was successfully used for tungsten CMP applications long before its application to copper films. Unlike copper, however, tungsten does not usually require the use of inhibitors in the slurries. Tungsten is a much harder metal in comparison to copper. Under oxidizing condition, tungsten has much better passivation characteristics. More... 

In the present study Fe(Pc)(Py)2 encaged into Y-zeolite is studied under catalytic conditions of oxidation of hydroquinone to benzoquinone in acetic acid media. Most of the measurements were performed in frozen slurries. The changes of characteristic Mossbauer data are correlated with proposed steps of the removal of pyridine ligands. From the comparison of data obtained at different temperatures the probability of the Mossbauer effect is also considered for identification of various iron species. Finally, the results are correlated with the catalytic properties, as well. 

XPS analysis of the SiC surfaces polished with different slurries allowed the different oxides formed on the surface to be characterized. The chemical state of carbon atoms at the SiC surfaces were analyzed in detail using the high-resolution XPS spectra, shown in Figure 7.2. Table 7.3 gives a comparison of the surface concentrations of the different carbonaceous species at the polished SiC surfaces. The C/Si atomic ratio was determined from the surface scan data. 

Figure-7-8. Comparison of SO2 removal efficiency as a function of the slurry chloride ion concentration for natural and forced oxidation conditions and three sources of chloride in a limestone-based FGD system. Data of Chang (1984)...

Figure 4-13 shows the effect of sodium metasilicate additions on the settling rate at elevated temperatures of a 250 g Th/kg H2O slurry of 800 C-fired oxide which had been micropulverized to an average particle size of 1 micron. At silica concentrations of 5000 to 30,000 parts Si02 per million Th02, the settling rates are reduced (by comparison with the pure slurry) at all temperatures up to 250°C, but the effect is more pronoimced at the lower temperatures. 

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