Abstract: In the disintegration of a chromite or chromium-containing residue, wherein the chromium-containing material is disintegrated with an alkaline compound in the presence of oxygen and a diluent at a temperature above about 800.degree. C. and thereafter leached, the improvement which comprises pre-roasting the chromium-containing material prior to addition of the alkaline compound. Pre-roasting can be effected at 400.degree. to 1200.degree. C. with addition of certain amounts of silica dioxide and/or aluminum oxide and such additives, depending on the chromium containing material, if still required, are added--prior to disintegration and leaching--in such a quantity to establish a ratio of SiO.sub.2 : AL.sub.2 O.sub.3 of about 2:1 and further a ratio, calculated on the basis of NaOH as the alkaline compound, of SiO.sub.2 : Na.sub.2 O of about 1:0.5 plus a Cr.sub.2 O.sub.3 : Na.sub.2 O ratio of about 1:2 to 1:4.

Abstract: Employing as surface active agents salts of perfluoroalkane sulphonamides, preferably of the formula ##STR1## in which R.sub.F is a perfluorinated aliphatic group having 4 to 20 C-atoms,R is a hydrogen atoms, an alkyl group having 1 to 4 C-atoms, a hydroxyalkyl group having 1 to 4 C-atoms or a cycloalkyl group having up to 6 C-atoms, andM is an alkali metal, an alkaline earth metal or an onium group of the formula[ZR.sub.2 R.sub.3 R.sub.4 R.sub.5 ].sup..sym.,Z is phosphorus or nitrogen, andR.sub.2 to R.sub.5 each independently is a hydrogen atom, or an alkyl, hydroxyalkyl, or alkoxyalkyl group having 1 to 4 C-atoms per alkyl moiety.

Abstract: 1,1-Difluoro-2-chloroethylene is used as the propellant in an aerosol spray can. It is reasonably stable and non-flammable but will in time degrade in the atmosphere.

Abstract: A process for the preparation of a hydroxyalkylperfluoroalkane sulphonamide of the formula ##STR1## wherein R.sub.F is a perfluoroalkyl group having from 1 to 20 carbon atoms;R and R' each independently is hydrogen or an alkyl, hydroxyalkyl, haloalkyl, cycloalkyl, aralkyl, alkenyl or aryl radical; andm and n each independently is an integer from 1 to about 30,comprising reacting a perfluoroalkylsulphonamide of the formula ##STR2## with an epoxide of the formula ##STR3## in the presence of a basic catalyst.

Abstract: In the production of linear and branched equilibrated acyloxy-containing organopolysiloxanes by reacting a chlorosilane of the formulaR.sub.a R'.sub.b SiCl.sub.(4-a-b)in whicha is 0,1,2 or 3,b is 0,1,2 or 3, anda+b.ltoreq.3,or a partial hydrolysate thereof, with at least one organosiloxane containing the componentsR.sub.2 R"--SiO.sub.1/2,R R"--SiO,R"--SiO.sub.3/2 andSiO.sub.2in whichR and R" each independently is H or an optionally halogen- or cyano-substituted monovalent hydrocarbon radical having up to 12 carbon atoms, andR" is Cl, OH, H or an optionally halogen- or cyano-substituted monovalent hydrocarbon radical having up to 12 carbon atoms,in the presence of an equilibration catalyst, the improvement which comprises employing as the equilibration catalyst a salt of a fluorinated alkane sulphonic acid plus a monobasic carboxylic acid, the total number of Si--Cl groups exceeding the total number of Si--OH groups in the reactants and the monobasic carboxylic acid being present in at least about 1.

Abstract: A process for the preparation of a perfluoroalkanesulphonic acid ester of the formulaC.sub.n F.sub.2n+1 SO.sub.3 Si R.sup.1 R.sup.2 R.sup.3comprising reacting a silane of the formulaR.sup.1 R.sup.2 R.sup.3 R.sup.4 Siwith a perfluoroalkanesulphonic acid of the formulaC.sub.n F.sub.2n+1 SO.sub.3 HwhereinR.sup.1, R.sup.2 and R.sup.3 each independently is alkyl with 1 to 6 carbon atoms,R.sup.4 is methyl, andn is from 1 to 12.Compounds wherein the total number of carbon atoms in Cn, R.sup.1, R.sup.2 and R.sup.3 is at least 6 are new and especially useful as silylating agents in organic cyntheses.

Abstract: In the production of a foamed synthetic material by the reaction of starting materials which undergo a polymerization, polycondensation or polyaddition reaction to produce a high molecular weight synthetic material in the presence of a blowing agent, e.g. a polyurethane, or by foaming an unfoamed thermoplastic synthetic material by means of a blowing agent, the improvement which comprises employing 1,1,1-trifluoro-2-chloroethane as the blowing agent, optionally in admixture with 1,1-difluoro-2-chloroethane.

Abstract: Production of tetraethyl ammonium perfluoroalkyl sulphonates (C.sub.2 H.sub.5).sub.4 N.sym.R.sub.F SO.sub.3 .crclbar., wherein R.sub.F represents a perfluorinated alkyl radical with about 4 to 10 carbon atoms, by reacting crude perfluoroalkyl sulphonic acid fluoride, i.e. perfluoroalkyl sulphonic acid fluoride which has not been especially purified, with triethylamine and an ethoxy silane, preferably dimethyl diethoxy silane, methyl triethoxy silane or tetraethoxy silane in an inert solvent at temperatures of about 10.degree. to 60.degree. C., preferably about 20.degree. to 40.degree. C. The process according to the invention is particularly suitable for the production of tetraethyl ammonium perfluorooctane sulphonate.

Abstract: A process for the preparation of a chrome-tanning agent and Glauber's salt from sodium bisulphate contaminated with chromium compounds obtained as by-product from the manufacture of chromic acid from solid sodium dichromate and sulphuric acid, comprising(a) treating an about 20 to 70% aqueous sodium bisulphate solution which contains chromium compounds and is acid with sulphuric acid with sulphur dioxide until all the chromium is present in the form of chromium (III);(b) adding sodium hydroxide to the reduced solution until it has a pH of between about 4 and 5;(c) adding sodium carbonate to the solution to a pH of between approximately 8 and 8.5, thereby precipitating chromium (III) hydroxide;(d) separating off the precipitated chromium (III) hydroxide; and(e) evaporating the filtrate left after removal of the chromium (III) hydroxide to yield solid sodium sulphate.

Abstract: In the production of a synthetic fluorspar of low silicon dioxide content wherein hexafluosilicic acid is added in an amount ranging from slightly below up to about stoichiometric amount to an aqueous calcium carbonate suspension at a temperature from about 0.degree. to 40.degree. C., and the calcium fluoride formed is separated off from the dilute silica sol and optionally washed out, the improvement which comprises reacting the calcium carbonate with the hexafluosilicic acid in such a way that the pH-value of the fully reacted solution amounts to between about 3.6 and 4.6, and adding a fast-reacting proton acceptor to the reaction mixture immediately before separation of the calcium fluoride in amount sufficient to raise the pH to about 5.0 to 6.4, preferably about 5.8 to 6.2. Suitable proton acceptors include the alkali metal and ammonium hydroxides carbonates and hydrogen carbonates or alkaline earth metal hydroxide.

Abstract: In the recovery of chromium from a residue containing chromate and vanadate, by oxidative decomposition of a chromium and vanadium-containing ore in the presence of an alkali at temperatures of about 600 to 1200.degree. C., and leaching such residue with water, the improvement which comprises adding titanium dioxide to the residue and heating, whereby upon leaching the chromium enters the water while the vanadium is substantially left in the residue.

Abstract: In the disintegration of at least one chromium source selected from the group consisting of a SiO.sub.2 -containing chromite and a chromium-containing residue with an alkali compound at a temperature above about 800.degree. C in the presence of atmospheric oxygen and a lime-free diluent, followed by leaching of the mixture with at least one of water and/or a chromium (VI)-containing aqueous solution, the improvement which comprises including in the mixture to be disintegrated an aluminum compound and at least sufficient alkali to form alkali chromate and to convert the SiO.sub.2 into an alkali-aluminum silicate corresponding to the formula nMe.sub.2 O . mSiO.sub.2 . Al.sub.2 O.sub.3, wherein Me is at least one of sodium and potassium, 0.8 .ltoreq. n .ltoreq. 1.2 and 1.3 .ltoreq. m .ltoreq. 4.3.

Abstract: In the chrome-tanning of skins with a chromium (III) salt and an acid-binding agent, the improvement which comprises effecting the chrome-tanning in the presence of a water-soluble partial ester of a polycarboxylic acid containing 4 to 11 carbon atoms which ester hydrolyzes into the free acid or its salt. The partial ester is advantageously present in about 0.5 to 2, preferably 1,3 to 1.8, times the molar amount of the chromium salt expressed as Cr.sub.2 O.sub.3. The tanning composition can be formed by dissolving the desired ingredients and the solution spray dried to provide a properly formulated powder which can thereafter by employed to re-formulate the solution.

Abstract: In the alkaline-oxidative disintegration of chromites into chromates with an alkali comprising reacting a chromium ore in the presence of oxygen and a diluent, and leaching the reaction mixture with at least one of water and/or a chromate-containing aqueous solution, the improvement which comprises reacting the residue obtained after leaching with an excess of alkali, based on the chromium oxide content of the residue, in the presence of oxygen, grinding the reaction mixture and, without leaching, employing the ground reaction mixture as an alkali source in another chromite disintegration cycle. The alkali reacted with the leaching residue is preferably sodium and/or potassium hydroxide and/or carbonate and is employed in about 100 to 400%, and preferably about 150 to 330%, of the stoichiometric amount based on the chromium oxide content of the leaching residue.

Abstract: In the etching of glass wherein glass is contacted with an aqueous etching bath containing hydrofluoric acid, and the glass is thereafter removed from the bath and rinsed, the improvement which comprises dissolving in the etching bath an acid-resistant wetting agent. Preferably the wetting agent contains fluorine, e.g. a perfluoralkane sulfonic acid quaternary ammonium salt, a perfluoralkane carboxylic acid salt, an alkoxylation product of a perfluoralkane sulfonamide, or the like.

Abstract: The present invention is concerned with a process for molding thermoplastic, high molecular weight aromatic polycarbonates the improvement which comprises adding to the aromatic polycarbonate from about 0.001 to 1% by weight of a mold release agent selected from the group consisting of perfluoroalkanesulphonic acid amides, cyclimmonium salts of perfluoroalkanesulphonic acids and ammonium salts of perfluoroalkanesulphonic acids.

Abstract: In the production of an ammonium fluoride solution by precipitating hexafluosilicic acid from its solution with ammonia and from the resulting suspension separating off the silicon dioxide precipitated, the improvement which comprises thoroughly mixing the hexafluosilicic acid solution and ammonia at a temperature of about 40.degree. to 90.degree. C, in such proportions that the suspension obtained contains at least 1% of free ammonia and at most 22% of ammonium fluoride, the average residence time of the reactants in the precipitation zone being at least 4 minutes. Advantageously, the silicon dioxide is separated off from the suspension obtained without previous cooling, the resulting ammonium fluoride filtrate is left standing for at least 30 minutes to permit flocculation of silicon dioxide contained therein and the flocculated silicon dioxide is separated off.

Abstract: The present invention is concerned with molding compositions which contain an aromatic polycarbonate and from about 0.001 to 1% by weight of a mold release agent selected from the group consisting of perfluoroalkanesulphonic acid amides and cyclimmonium salts of perfluoroalkanesulphonic acids.

Abstract: In the electrodeposition of a chrome layer wherein the chrome is deposited from an electrolyte solution containing a hexavalent chromium compound in the presence of a fluorine-based surfactant, the improvement which comprises employing as the fluorine-based surfactant a quaternary ammonium perfluoralkane sulfonate of the formula[R.sub.F SO.sub.3 ].sup.- [NR.sup.1 R.sup.2 R.sup.3 R.sup.4 ].sup.+in which R.sup.1,R.sup.2, R.sup.3 and R.sup.4 each individually is alkyl, alkenyl, cycloalkyl or aralkyl of up to 18 carbon atoms, or two or three of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 together with the nitrogen atom to which they are attached form a heterocyclic ring, and R.sub.F is a perfluorinated alkyl radical with 6 to 12 carbon atoms.Additives such as Na.sub.2 CO.sub.3, NaHCO.sub.3, Na.sub.2 CrO.sub.4, K.sub.2 CrO.sub.4, Na.sub.2 Cr.sub.2 O.sub.7 and K.sub.2 Cr.sub.2 O.sub.7 or water may also be admixed with the quaternary ammonium perfluoralkane sulfonate.

Abstract: In the electrochemical fluorination of an alkanesulfonyl halide wherein an electric current is passed through a cell containing said alkanesulfonyl halide dissolved in hydrofluoric acid to produce a perfluorinated alkanesulfonyl fluoride, the improvement which comprises including in said cell an unsaturated cyclic sulfone.