Hoechst Aktiengesellschaft

Vinnolit Monomer Gmbh & Co. Kg

Siegfried Benninger

Thomas Martini

Karl Reining

Werner Krasel

Siegfried Rebsdat

Jurgen Stenzel

Adolf Schmidt

Hans Herbst

The preparation of tin tetrachloride from tin granules and chlorine can be conducted safely even at high temperatures if the chlorine, before coming into contact with the tin, is brought into a highly disperse distribution in the circulating tin tetrachloride and develops a uniform flow profile.

Process for preparing tin tetrachloride

Chromosulfuric acid, which is used in many organic reactions as an oxidizing agent, can advantageously be regenerated electrochemically if an electrolysis cell is used which comprises two tub-like half shells with a current-permeable, hydraulically sealing partition situated inbetween. The hydrogen produced at the cathode can also be extracted and utilized in this way.

Process for electrochemically regenerating chromosulfuric acid

The invention relates to an open dissolving chamber for rock salt and to an apparatus for the production, free from vapors, of concentrated, aqueous sodium chloride crude brine by continuously dissolving rock salt in this dissolving chamber. The dissolving chamber contains a heap of rock salt with which the brine which is unsaturated in respect of salt comes into contact. The brine thereby becomes saturated with sodium chloride and then passes out of the dissolving chamber. In the present apparatus, the unsaturated brine enters at the base of the dissolving chamber. The saturated crude brine is removed from the rock salt through at least one vertical or inclined screen which largely holds back suspended rock salt particles. The liquid level of the saturated crude brine in the dissolving chamber should not reach the surface of the heap of rock salt, and the side of the screen facing the interior of the dissolving chamber should be completely covered with a mixture of saturated crude brine and rock salt.

Apparatus for the production of aqueous solutions of sodium chloride

The invention relates to an open dissolving chamber for rock salt and to a process for the production, free from vapors, of concentrated, aqueous sodium chloride crude brine by continuously dissolving rock salt in this dissolving chamber. The dissolving chamber contains a heap of rock salt with which the brine which is unsaturated in respect of salt comes into contact. The brine thereby becomes saturated with sodium chloride and then passes out of the dissolving chamber. In the present process, the unsaturated brine enters at the base of the dissolving chamber. The saturated crude brine is removed from the rock salt through at least one vertical or inclined screen which largely holds back suspended rock salt particles. The liquid level of the saturated crude brine in the dissolving chamber should not reach the surface of the heap of rock salt, and the side of the screen facing the interior of the dissolving chamber should be completely covered with a mixture of saturated crude brine and rock salt.

Process for the production of aqueous solutions of sodium chloride from

Brine (an aqueous solution of alkali metal chlorine) which is electrolyzed according to the amalgamation process, generally contains small amounts of mercury. It has been found that these traces of mercury are entrained with the evaporated water in a considerable amount when applying evaporation cooling to the brine. In order to keep these losses as low as possible, a pH of from 7 to 9.0 and a redox potential more than 1391-6.66(pH)-5.94(pH).sup.2 but not more than 1100 mV (based on the potential of the hydrogen electrode) is adjusted by adding chlorine or alkali metal hypochlorite and optionally alkali metal hydroxide to the brine.

Process for reducing losses of mercury in alkali metal chloride

New and useful perfluorinated cyclohexyl ethers are manufactured by reacting a phenol with hexafluoro propene or tetrafluoro ethylene, dissolving the partly fluorinated phenyl alkyl ethers obtained in hydrofluoric acid and electrolyzing the solution.

Perfluorocyclohexyl ethers

By reacting tertiary amines carrying hydroxyethyl or 2-hydroxypropyl groups with hexafluoropropene in an aprotic solvent in the presence of a basic catalyst such as triethylamine the hexafluoropropyl ether of the starting compound containing the group ##STR1## with X = CH.sub.3 or H is obtained.

Partially fluorinated amino ethers

Mono- or polyhydric alcohols of the alkan-, tetrahydrofuran- or tetrahydropyran series or di- or tri-alkyleneglycols are dissolved in an aprotic polar solvent and reacted with C.sub.3 F.sub.6 in the presence of trialkylamines, or with tetrafluoroethylene to give the corresponding tetrafluoroethyl- or hexafluoropropyl ethers. The solution of the fluoroethers in anhydrous hydrofluoric acid is electrolyzed. Hydrogen-free perfluoroethers are obtained.

Aliphatic and cyclic perfluoro-alkyl ethers and process for the

Branched perfluoro-olefins are electrofluorinated in an electrolytic cell at about 4-6.6 volts at a temperature of from 0.degree. to 20.degree.C together with anhydrous hydrogen fluoride. Branched perfluoro-alkanes are obtained in high yield.

Growing community of inventors

Schwalbach, Taunus, Germany

Siegfried Benninger