Abstract: Processes are described which include: (a) providing an initial crude alkali metal chloride brine; (b) mixing the initial crude brine with a recirculated brine to form a process brine steam; (c) subjecting the process brine stream to electrolysis to form chlorine gas and an electrolyzed weak brine; and (d) subjecting the electrolyzed weak brine to a post-electrolysis salt enrichment comprising (i) diverting a substream of the electrolyzed weak brine at a post-electrolysis diversion point; (ii) removing water from the substream; (iii) crystallizing salt present in the substream; (iv) separating the crystallized salt from the substream; and (v) introducing the separated salt into the electrolyzed weak brine to form the recirculated brine.

Abstract: The present invention relates to a method of increasing the concentration of dilute brine in NaCl electrolysis plants using the membrane process, wherein the NaCl required is stored in a mass flow silo with supernatant liquid and is fed continuously from there to the quick dissolver.

Abstract: In the continuous production of oleum having a concentration of 10 to 45% by weight SO.sub.3 and/or sulfuric acid having a concentration of 94 to 100% by weight H.sub.2 SO.sub.4 by burning sulfur with atomospheric oxygen on the principle of overstoichiometric or understoichiometric burning, cooling the resulting SO.sub.2 -containing gas to 390.degree.-480.degree. C., catalytically reacting the cooled gas to SO.sub.3 -containing gas on a vanadium-containing catalyst on the principle of single- or double-contact catalysis, absorbing the SO.sub.3 -containing gas after cooling and, optionally, separating liquid from the gas after absorption, followed by recovering energy, the improvement which comprises effecting the burning of the sulfur with atomospheric oxygen in the presence of a dry SO.sub.2 -containing gas which contains up to 5,000 ppm (NO).sub.x expressed as NO.

Abstract: A process for preventing the caking of particles of ammonium bifluoride and/or ammonium fluoride salt mixtures or salts subjected to the action of temperature, pressure and/or moisture, the process comprising spraying on said particles a solution comprising a primary, secondary or tertiary amine carrying an alkyl group with 8 to 25 carbon atoms.

Abstract: To render surfaces, such as of textile fabrics and fibers, repellent to oil and/or water, they are treated with novel polyurethanes containing perfluoroalkyl ligands and having as recurring structural units ##STR1## with chain ends of the formula--YA.sub.m'in whichX, Y and Z each independently is the skeletal radical of an aliphatic or aromatic di- or polyisocyanate,R.sub.

Abstract: The instant invention relates to a process for the preparation of linear aromatic polycarbonate resins by the known two-phase interfacial process and is directed to the use of perfluoroalkyl sulfonamides as chain stoppers in said process and is further directed to the polycarbonate resins obtainable by the process which resins are suitable in the preparation of thermoplastic molding compositions.

Abstract: A process for the removal of sulfuryl fluoride from exhaust gases is improved by reacting sulfuryl fluoride in the exhaust gases with a dilute aqueous alkali metal hydroxide or alkali metal carbonate solution on an active carbon catalyst.

Abstract: Electrochemical fluorination of a thiophene-1,1-dioxide derivative of the formula ##STR1## produces the novel perfluorinated sulphonic acid fluoride of the formula ##STR2## in which X, Y and Z each independently is F, a perfluoroalkyl group having 1 to 8 C-atoms in which one or more CF.sub.2 groups may optionally be replaced by oxygen, the oxygen atoms being separated by at least one CF.sub.2 group, optionally perfluoroalkyl-substituted cycloperfluoroalkyl group having 5 to 12 C-atoms in which one or more CF.sub.2 groups may be replaced by oxygen, orX and Y together denote an optionally perfluoroalkyl-substituted cycloperfluoroalkyl group in which one or more CF.sub.2 groups may be replaced by oxygen,R.sub.f each independently is F or a perfluoroalkyl group having 1 to 3 C-atoms, andn and m each independently is 0 or 1.The products are useful as surface active agents.

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.