Mud, Jamaican red

The pK of Ca2+aq (204), 12.6 at zero ionic strength, rising to over 13 as ionic strength increases, means that concentrations of CaOH+aq will be negligible in body fluids (lpolluted waters, and under all conditions of biological relevance, from the very low pHs of 0.5 (Thiobacillus thiooxidans) to 1.5 at which bacteria used for oxidative metal extraction operate (205), through acid soils and acid rain (pH 3 to 6), streams, rivers, and oceans (pH 6 to 8), soda lakes (pH 10), up to the pHs of 11 or more in Jamaican Red Mud slurry ponds (206) (cf. Section II.C.l below). 

When an iron-rich catalyst such as Jamaican red mud (20 g at 380°C) was used in this test, it not only exhibited much higher levels of catalytic activity, but it was also only slightly affected by the presence of up to 25% water vapor in the inlet gas. This is demonstrated by curve c of Figure 1. Thus, in order to suppress the adverse effect of water vapor on the catalytic reduction of sulfur dioxide with carbon monoxide,... 

The preceding test was repeated with 20 g of Jamaican red mud catalyst replacing the red bauxite at 420 °C. The results in Figure 3 indicate that up to 20% water vapor slightly inhibited the sulfur dioxide conversion on this iron-rich catalyst. In absence of water, carbonyl sulfide was formed (curve a), but with water, hydrogen sulfide (curve c) was formed instead. 

Figure 3. Effect of water vapor on the catalytic activity of Jamaican red mud a = carbonyl sulfide, b = sulfur dioxide, c = hydrogen sulfide,...

Single-Bed, Nonisothermal Catalysts. In an attempt to circumvent the undesirable formation of hydrogen sulfide in the presence of water vapor, a nonisothermal reactor was constructed by placing 536 g of Jamaican red mud catalyst in a 2-cm diameter 96%-silica tube. The catalyst-filled tube was inserted into the bottom half of the furnace. This resulted in a 15-cm uniform temperature hot zone and a 25-cm zone with temperatures gradually decreasing to about 100 °C at the lower reactor exit. The inlet gas consisted of 17% water vapor, 5.8% carbon monoxide, and 3.0% sulfur dioxide, and 74.2% helium. Figure 5 shows the dependence of the exhaust gas analysis on the hot-zone temperature of the Jamaican red mud catalyst. No sulfur dioxide was removed at hot-zone temperatures lower than 240 °C. At 250 °C, some sulfur dioxide was removed, and small quantities of hydrogen sulfide were formed. Above 300°C, more than 80% of the sulfur dioxide and virtually all of the carbon monoxide... 

Figure 5. Effect of temperature of Jamaican red mud catalyst on exhaust gas analysis. Inlet gas 3% sulfur dioxide, 5.8% carbon monoxide, and 17% water vapor in helium.

The samples were dried, pulverized to 100 mesh, briquetted into minus 16- plus 20-mesh pellets, and indurated at 600 °C for 6 hr. The chemical and physical properties of these catalysts are given in Table I. The Berbece bauxite, a product of British Guiana, was obtained from Milwhite Co., Inc., Houston, Tex. The Arkansas red bauxite was obtained from David New-Minerals, Providence, Utah. The Jamaican and Surinam red mud samples were supplied by the Federal Bureau of Mines Albany Metallurgy Research Center, Albany, Oreg. 

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