Abstract: The present invention relates to a process for the treatment of waste waters containing common salt, characterised in that, by a specific sequence of acidification, extraction, alkalisation and stripping steps, an aqueous common salt solution is obtained, which can be used directly in chlor-alkali electrolysis.

Abstract: A method for producing a bisphenol is disclosed. The method entails reacting in at least one first reactant selected from a first group consisting of phenol and substituted phenols with at least one second reactant selected from a second group consisting of ketones and diols, in the presence of hydrogen chloride catalyst and volatile sulphur compound having an SH bond as co-catalyst. The reaction product is a mixture that contains bisphenol, first reactant and second reactant. The catalyst and co-catalyst and water of reaction are separated by distillation. The method is characterized by the high reaction rates and selectivities.

Abstract: The present invention provides a process for preparing benzothiazolyl sulfenamides by reacting primary amines with alkali metal salts of mercaptobenzthiazole in the presence of hydrogen peroxide and alkali metal hypochlorite. The process according to the present invention is characterized by high rates of conversion, wherein the benzothiazolyl sulfenamides obtained are obtained with high purity, in high yields and with high storage-stability, even at elevated temperatures and high humidity.

Abstract: Nitrate-containing (contaminated) solutions are reduced with SO2 gas in the presence of an at least equimolar amount of NH4+ or ammonium salt.

Abstract: Method of dispensing moist, sticky or statically charged bulk material into a fluid pervious container having an opening for receiving said bulk material, which comprises conveying a bulk material, as a suspension or dispersion in a fluid, from a reservoir, and introducing said suspension or dispersion into the fluid-pervious container through said opening in the container to pass the fluid component of the suspension or dispersion through and out of the fluid-pervious container while the retaining the bulk material within the container, and recirculating the fluid to the reservoir.

Abstract: A method for producing a bisphenol is disclosed. The method entails reacting in at least one first reactant selected from a first group consisting of phenol and substituted phenols with at least one second reactant selected from a second group consisting of ketones and diols, in the presence of hydrogen chloride catalyst and volatile sulphur compound having an SH bond as co-catalyst. The reaction product is a mixture that contains bisphenol, first reactant and second reactant. The catalyst and co-catalyst and water of reaction are separated by distillation. The method is characterized by the high reaction rates and selectivities.

Abstract: Method of dispensing moist, sticky or statically charged bulk material into a fluid pervious container having an opening for receiving said bulk material, which comprises conveying a bulk material, as a suspension or dispersion in a fluid, from a reservoir, and introducing said suspension or dispersion into the fluid-pervious container through said opening in the container to pass the fluid component of the suspension or dispersion through and out of the fluid-pervious container while the retaining the bulk material within the container, and recirculating the fluid to the reservoir.

Abstract: Nitrate-containing (contaminated) solutions are reduced with SO2 gas in the presence of an at least equimolar amount of NH4+ or ammonium salt.

Abstract: The present invention relates to a process for the production of bis(4-hydroxyaryl)alkanes by an acid-catalyzed reaction between aromatic hydroxy compounds and ketones, in which the temperature, ketone content and water content of a liquid reaction mixture are adjusted by means of a suitably composed gas phase.

Abstract: This invention relates to a process for the purification of waste waters containing organic and, should the situation arise, inorganic sulphur compounds, which waste waters contain a proportion of mercaptobenzothiazole and/or derivatives thereof and, should the situation arise, a proportion of benzothiazole and/or derivatives thereof and/or mercaptobenzimidazole and/or derivatives thereof and, should the situation arise, thiosulphate, whereby the waste waters are treated with an extracting agent comprising salts of aliphatic amines and aliphatic and/or aromatic hydrocarbons.

Abstract: A continuous process for the removal of at least one of nitrate and organic contaminants from an aqueous effluent, which process comprises subjecting said effluent to extractive liquid ion-exchange with a long-chain alkylamine dissolved in an organic solvent and present in salt form, and reextracting the loaded organic phase with a base, the treated effluent being recycled for reuse.

Abstract: High-grade titanium dioxide is produced by(a) reacting ilmenite or titanium-containing slag with sulfuric acid,(b) dissolving the material from (a) with water or dilute sulfuric acid,(c) separating insolubles from (b) to obtain a black solution containing titanyl sulfate and foreign metal salts,extracting titanyl sulfate from the black liquor with sulfuric acid and an organic medium containing an organophosphorus compound, separating the foreign metal salts in an aqueous extract phase, recovering titanyl sulfate from the organic extract phase, andhydrolyzing the titanyl sulfate to titanium oxide hydrate.

Abstract: A process for the complete recovery of NO from the waste gas of ammonium nitrite production, in which gases containing nitrogen oxides are absorbed in a first stage in a solution of ammonium carbonate and/or ammonium bicarbonate to form ammonium nitrite solutions and the resulting waste gas containing carbon dioxide is absorbed in a second stage in an ammoniacal, aqueous solution to form ammonium carbonate and/or ammonium bicarbonate which is returned as such to the first absorption stage, and the waste gas containing carbon dioxide is brought into contact with a sulphuric acid of medium concentration containing from 0.1-5% by weight, preferably from 0.2 to 1.5% by weight of nitric acid before the carbon dioxide is introduced into the second absorption stage.

Abstract: Nitrogen oxide is removed from flue gases of combustion plants or reaction gases by a process wherein the nitrogen oxide contained in the stream of gas is converted into a stochiometric composition of N.sub.2 O.sub.3 and removed from the gas stream.

Abstract: An improved work-up of aqueous mother liquors which originate from the oxidative preparation of benzothiazolylsulphenamides and which contain unreacted amine or a low-boiling alcohol employed as solubilizer, or both, the work-up being carried out in such a fashion that the mother liquor is saturated by additives until two phases form, the phases are separated from one another, the aqueous phase is extracted with further alcohol or amine, amine, alcohol and the extracted components are isolated from the combined organic phases, and amine or alcohol dissolved in the aqueous phase is removed therefrom by distillation.

Abstract: A process for the working up of ammonium sulphate-containing effluent which is contaminated with organic compounds and optionally also ammonium nitrate, comprising evaporating the effluent to produce water vapor which is removed, a concentrated liquid and a crystal suspension, thickening the suspension to obtain solid ammonium sulphate which is removed and liquid which is recycled to an earlier stage, subjecting the concentrated liquid from evaporation to an optional vacuum cooling crystallization to obtain water vapor which is removed and a crystal suspension from which a concentrated liquid is separated off, advancing the concentrated liquid from the evaporation stage or from the vacuum cooling crystallization stage to a crystallizer, introducing ammonia into the crystallizer to decrease the solubility of the ammonium sulphate, thickening the ammoniacal crystal suspension to obtain ammonium sulphate solids which are removed and ammoniacal mother liquor which is advanced to a distillation step for recovery o