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: 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: The invention relates to a process for the production of multilayer plastic sheets from special branched polycarbonates.

Abstract: A process for preparing bisphenol A which has a purity of at least 99.95 wt. % of p,p-bisphenol A (BPA). Thermally stable and colour-stable BPA purified in accordance with the invention produces improved thermal and colour stability and improved optical transparency in polymers such as e.g. polycarbonates prepared therefrom.

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.