Mixed sulfates

Indirect Hydration. Indirect hydration is based on a two-step reaction of propylene and sulfuric acid. In the first step, mixed sulfate esters, primarily isopropyl hydrogen sulfate, but also diisopropyl sulfate, form. These are then hydrolyzed, forming the alcohol and sulfuric acid. 

An alternative process for opening bastnasite is used ia Chiaa high temperature roastiag with sulfuric acid followed by an aqueous leach produces a solution containing the Ln elements. Ln is then precipitated by addition of sodium chloride as a mixed sulfate. Controlled precipitation of hydroxide can remove impurities and the Ln content is eventually taken up ia HCl. The initial cerium-containing product, oace the heavy metals Sm and beyond have been removed, is a light lanthanide (La, Ce, Pr, and Nd) rare-earth chloride. 

Industrial wastewater containing precursors and synthesis products of 15 sulfonated azo dyes Anaerobic baffled reactor containing mixed sulfate reducing bacteria, and methanogens In an anaerobic baffled reactor, almost a complete removal of color was observed in the reactor within 100 days of operation [182]... 

Alkylation of Etiolates with Chiral Selenonium Salts, Sulfonium Salts and Mixed Sulfates... 

An asymmetric synthesis of a-amino acids uses the alkylation of glycine enolates by mixed sulfates, e.g., methyl 1,2 5,6-di-O-isopropylidene-a-D-glucofuranose 3-sulfate, bearing a chiral leaving group1 13-15. 

The mixed sulfates are prepared by transformation of alcohols obtained from D-( + glucose with chloro methyl sulfite into mixed sulfites which are then oxidized with potassium permanganate under phase transfer catalysis into the corresponding sulfates14. 

After deprotonation of (V-methoxycarbonylmethyldiphenylmethanimine with lithium diiso-propylamide in THF, the a-methylation with various mixed sulfates leads after acidification to (S)-2-aminopropanoic acid (L-alanine) in a yield of 40 60% and an ee as high as 40% 13 14. 

The best alkylation occurs at low temperature in the presence of 10 12 equivalents of hexamethylphosphoric triamide (HMPA). Without IIMPA, the enantiomeric excesses arc lower and the methylation is slower. Furthermore, the chiral moiety of the mixed sulfate, as well as the Schiff base moiety of the methyl glycinate, determines the outcome of the a-alkylations. 

Fig. 6 (a). Three-dimensional Ni(ll) sulfate in [C4N2H 2][Ni2F4(S04) HjO], XIX, showing 10-membered elliptical channels from ref. 66, (b) Polyhedral view of ihree-dimensional zinc sulfate comprising Zn04 and SO,L letrahedra in [(CN J Vbl Zn(S04Jij, XX, redrawn from ref, 78, Note the presence of 12-membered channels, (c) Three-dimensional structure of scandium with mixed sulfate and phosphate telrahedra in XXI, redrawn from ref, 81, copyrighl (2002) from the Royal Society of Chemistry. 

Other examples are the dibasic phosphates, arsenates, mixed sulfates, and similar compounds—KH2PO4, NH4H2ASO4, Ag2H3lOe, (NH4)8A1(S04)2 6H20, and (NH4)2S04. (See 305 for a general treatment of ferroelectrics.)... 

The International Nickel Company developed a method to refine impure nickel sulfide anodes directly to metal, using mixed sulfate-chloride electrolyte [45]. Nickel sulfide (cz-Nf ) anodes can be cast directly from low-copper converter matte or from melted nickel sulfide concentrate produced by the matte separation process. Controlled cooling is necessary to produce anodes with the required mechanical properties. The cooling of anodes can take up to 36 hours. Using nickel sulfide anodes eliminates the intermediate roasting of the sulfide... 

In a similar way, Na2SO4 has been used as an auxiliary electrode with sodium ion conductors (Na P alumina [179] or NASICON [180]). As with carbonates for CO2 sensors, mixed sulfates (e.g., Na2SO4-BaSO4 [181]) can be used for the auxiliary electrode. At low oxygen partial pressures, sulfur maybe present as H2S, rather than as SOx, in which case sulfides can be used as auxiliary electrodes. For example, CaS has been used with a CaF2 electrolyte for measuring H2S gas concentrations [182]. 

Separation. — The separation of thorium from the rare earth metals with which it is still mixed may be accomplished by three methods (1) the carbonate separation depends on the fact that thorium carbonate is much more soluble in sodium carbonate than the carbonates of the rare earth metals (2) by the fractional crystallization of the mixed sulfates at 15°-20°, crystals of Th(S04)2 8 H20 are obtained at the insoluble end of the series (3) thorium oxalate forms a soluble double salt with ammonium oxalate, while the rare earth oxalates are almost insoluble in this reagent. Some other methods which have been suggested are fractionation of the chromates,4 of the hydrogen alkyl sulfates,5 of the acetates, by the use of sebacic add 6 and hydrogen peroxide. 

A mixture containing only BaO and CaO weighs 2.00 g. The oxides are converted to the corresponding mixed sulfates, which weigh 4.00 g. Calculate the percent Ba and Ca in the original mixture. 

The mixed sulfates of the alkaloids of Alstonia constricta F. Mnoll resemble the cinchona alkaloids in many of their pharmacological actions. Oxytocic activity has been reported by both Sharp (171) and Keogh and Shaw (172). On the isolated uterus of the rat and guinea pig, both a stimulant and depressant action was observed, but the effect was always similar to that of quinine on any one particular preparation. Powerful contraction of the cat uterus in situ was produced by doses of 20.0 mg. administered intravenously. 

Note that the concentration product of nitric acid and ammonia in equilibrium with a mixed sulfate-nitrate solution having a value of T = 0.5 is about one-half as high as that in equilibrium with a pure ammonium nitrate solution. The temperature dependence of the partial-pressure product for the aqueous mixed-salt case is similar to that of the pure salt. 

Pyrite/Jaros ite Silicate/Sulfur Silicate/Pyrite Mixed sulfate/sulfide Mixed Carbonate Mixed Chloride... 

Copper oxide alone or treated with small amounts of silver nitrate to form a couple, or mixed sulfates of copper and silver on silica gel are nearly inert (18). 

TLD 100) low Z phosphor. However, our material LiNaS04 Cu is near to low Z (Zjff= 11.59). Cu is a successful dopant for various types of phosphors and in sulfates of lithium and sodium has been tried in this mixed sulfate. The ionic radius and oxidation state of Cu+ ion are better match for replacing Li in LiNaS04 crystal. 

If precursor complexes are formed in sulfuric acid solutions, they will almost certainly be mixed sulfate-carboxylate complexes, and the thermodynamic data will be of only peripheral use. In nitrate and especially perchlorate media, the thermodynamic data should be directly comparable as Ce(IV)-N03 complexes are weak and perchlorate complexes are unknown in aqueous solutions. It should be possible to compare the calculated constants with the kinetically derived data to gain further insight into the nature of the precursor complexes, and to assess the validity of authors claims with respect to complex stability and stoichiometry. 

R.D. Bryant, W. Jansen, J. Boivin, E.J. Laishley, J.W. Costerton. Effect of hydrogenase and mixed sulfate-reducing bacterial populations on the corrosion of steel. Applied and Environmental Microbiology, No. 57, No. 10, pp. 2804-2809, 1991. 

These components are present in the form of complex, mixed sulfates, e.g., darapskite (NaNOa Na2S04 H2O). 

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