Hydroxy sulfate

Some substituted alkyl hydrogen sulfates are readily prepared. Eor example, 2-chloroethyl hydrogen sulfate [36168-93-1] is obtained by treating ethylene chlorohydrin with sulfuhc acid or amidosulfuhc acid. Heating hydroxy sulfates of amino alcohols produces the corresponding sulfuhc monoester... 

More recendy, the molten caustic leaching (MCL) process developed by TRW, Inc. has received attention (28,31,32). This process is illustrated in Eigure 6. A coal is fed to a rotary kiln to convert both the mineral matter and the sulfur into water- or acid-soluble compounds. The coal cake discharged from the kiln is washed first with water and then with dilute sulfuric acid solution countercurrendy. The efduent is treated with lime to precipitate out calcium sulfate, iron hydroxide, and sodium—iron hydroxy sulfate. The MCL process can typically produce ultraclean coal having 0.4 to 0.7% sulfur, 0.1 to 0.65% ash, and 25.5 to 14.8 MJ/kg (6100—3500 kcal/kg) from a high sulfur, ie, 4 wt % sulfur and ca 11 wt % ash, coal. The moisture content of the product coal varies from 10 to 50%. 

G.L. Grandjean, E. (eds.) Mdssbauer spectroscopy applied to inorganic chemistry. Plenum Publ. Corp., 3 417-444 Webb, J. Macey, D.J. Mann, S. (1989) Biomineralization of iron in molluscan teeth. In Mann, S. Webb, J. Williams, R.J.P. (eds.) Biomineralization Chemical and biochemical perspectives. VCH Weinheim, 345-387 Webster, J.G. Swedlund, P.J. Webster, K.S. (1998) Trace metal adsorption onto an acid mine drainage iron(lll) oxy hydroxy sulfate. Environ. Sci.Techn. 32 1361-1368 Wedepohl, K.H. (1969) Composition and abundance of common igneous rocks. In Wedepohl, K.H. (ed.) Handbook of geochemistry. Springer, Berlin, 1 227-249 Wedepohl, K.H. (1969a) Composition and abundance of common sedimentary rocks. 

N1 - 1.3-BENZENEDIMETHANOL, alpha tup 1)- (11,1-DIMETHYLETHYL(AMINO (METHYL (-4-HYDROXY-, SULFATE (2tl( 1 SALT >... 

Rossman, G. R. (1975) Spectroscopic and magnetic studies of ferric iron hydroxy sulfates intensification of color in ferric iron clusters bridged by a single hydroxide ion. Amer. Mineral., 60, 698-704. 

The exposure of sulfide minerals contained in mine wastes to atmospheric oxygen results in the oxidation of these minerals. The oxidation reactions are accelerated by the catalytic effects of iron hydrolysis and sulfide-oxidizing bacteria. The oxidation of sulfide minerals results in the depletion of minerals in the mine waste, and the release of H, SO4, Fe(II), and other metals to the water flowing through the wastes. The most abundant solid-phase products of the reactions are typically ferric oxyhydroxide or hydroxysulfate minerals. Other secondary metal sulfate, hydroxide, hydroxy sulfate, carbonate, arsenate, and phosphate precipitates also form. These secondary phases limit the concentrations of dissolved metals released from mine wastes. 

Webster J. G., Swedlund P. J., and Webster K. S. (1998) Trace metal adsorption onto an acid drainage iron(III) oxy hydroxy sulfate. Environ. Sci. Technol. 23, 1361—1368. 

Once they have reached higher pH, reducing conditions of the intestinal tract (Davis et al, 1992), sulhdes should be more stable, and may actually precipitate if reduced sulfur is present. Other solids, such as hydroxides or hydroxy-sulfates of aluminum, and possibly iron, may also precipitate. The increased pH should also lead to the increased sorption onto particulates of various metals and metalloids such as lead and copper (Smith, 1999). However, in vitro tests (Ruby et al, 1993) indicate that the increased complexing with unprotonated organic acids and enzymes helps offset the pH-driven precipitation and sorption of the base metals that were dominantly chloride-complexed in the stomach fluids. Arsenic and other oxyanionic species are likely to be sorbed as the stomach acids are neutralized, but may be partially desorbed once higher pH values are reached in the intestine (Ruby et al, 1996). 

Arylamine— o-hydroxy sulfate esterf In an alkaline medium, arylamines are oxidized by the reagent to o-hydroxy sulfate ester salts. Thus a solution of 5 g. of N,N-dimethylaniline in 250 ml. of water, 400 ml. of acetone, and 30 ml. of 2N potassium hydroxide was stirred at room temperature during addition in 8 hrs. of... 

Sulfate Minerals (Figure 6.6) Fifteen sulfate minerals are present in the thermodynamic database. The calculations show that many are supersaturated in our water samples. Several members of the alunite-jarosite group are grossly supersaturated, but alunite and jarosite are known to be supersaturated without precipitating in some acidic surface waters (Alpers et al., 1994). Aluminum hydroxy sulfates, Al(OH)SC>4 (jurbanite), and Al4(OH)ioSQ4 (basaluminite), are also supersaturated at some points... 

A study of the chemistry of a small California stream that receives acid mine water (27) showed that above pH 4.9 the dissolved aluminum concentration appeared to be controlled by aluminum hydroxide solubility equilibria, but below pH 4.6 aluminum hydroxy-sulfates apparently predominated. This study also cited data for acid mine drainage in the Appalachian region and lakes affected by acid precipitation that showed a similar pattern of aluminum behavior. 

Sulfation of lead hydroxides, lead hydroxy-sulfate B layer, (a) PbS04 crystals (encircled) are formed on the surface of the large pore in the lead hydroxy-sulfate agglomerate (b) small IBS crystals can be seen in the right hand bottom part of the picture [4]. 

The structure of the 4BS paste at a distance of about 250 pm from the plate surface changes after 2 h of soaking in 1.25 rel. dens. H2SO4 solution (see Fig. 9.28). Figure 9.28a shows a picture of a 4BS crystal with hydrated and then partially sulfated surface. At a certain pH level, 4BS crystals react with water forming hydroxy-sulfates in the form of small particles (Fig. 9.28b). The latter may merge with the hydrated layers of the adjacent 4BS crystals (Fig. 9.28a). Thus, a continuous hydrated porous structure is formed, which is then sulfated. 

In presence of SO2 hydroxy-sulfates (basic sulfates) described by the general formula Zn(0H)x(S04)y can form. These products are weakly soluble in neutral environments, but exhibit a high solubility under acid conditions. In a highly polluted atmosphere, the pH of the electrolyte on the zinc surface can drop to sufficiently low values for the hydroxy-sulfates and the hydroxy-carbonates to dissolve. Rain water running off the surface can carry them away and thus accelerate corrosion. Several studies have shown a linear relationship between the rate of zinc corrosion and the SO2 concentration in the atmosphere. 

The presence of chlorides or sulfates leads to the formation of the hydroxy-chlorides A1(0H)2C1 and Al(OH)Cl2 or of hydroxy-sulfates Al(0H)x(S04)y. These compounds dissolve in acidic environments and the resulting corrosion products are carried away by run-off water. However, even in a polluted atmosphere, the uniform corrosion rate of aluminum remains generally small. On the other hand, in presence of chloride pollution, damage by pitting may occur. 

Upon contact with the atmosphere, copper forms a brown-black patina that becomes blue-green over the years. The changing color is explained as follows. Initially the oxides CU2O and CuO arc formed. Then, in the presence of pollutants, the oxides slowly transform into greenish hydroxy-sulfates Cu(0H)x(S04)y, hydroxy-carbonates Cu(0H)x(C03)y or hydroxy-chlorides Cu(OH)xCly. Normally the patina has little or no influence on the rate of corrosion, which remains constant during the time of exposure. Uncoated copper structures exposed to the atmosphere, such as for roofing, corrode only very slowly and last many years. More critical than the loss of copper due to atmospheric corrosion is a possible environmental pollution by copper ions formed by corrosion reactions and carried away by rainwater. 

Green patina, whose decorative aspect is highly appreciated, contains mostly basic salts. Their exact composition depends on the atmospheric conditions. In urban atmospheres they are mostly composed of hydroxy-sulfates and in marine atmospheres of hydroxy-chlorides. The patina forms more rapidly in polluted atmospheres, but even so, one generally has to wait a few years for a green patina to appear. Environments with a high SO2 concentration can prevent entirely the formation of the green patina, because the surface pH of the metal remains too low for the precipitation of basic salts. 

Calcium aluminum hydroxy-sulfate hydrate Ettringite (hexagonal) 6Ca0.Al20,.3S0,.32H,0 = CaAl2(S0.)3(0H) .26H,0 QAS,H,2... 

In laboratory tests at 35°C and 25°C, with 90% RH, NO2 does not promote the corrosion of zinc. However, an accelerant effect was observed when SO2 and NO2 are combined, resulting in the formation of a greater proportion of zinc hydroxy sulfate. This effect was greater at 25°C than at 25°C, probably because higher temperatures make difficult the formation of a moisture layer and less electrolyte is deposited on the zinc surface. The nitrogen dioxide effect is indirect given that nitrogen compounds have not been detected... 

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