Basf Aktiengesellschaft

Hans-Michael Schneider

Bernd Leutner

Otto Watzenberger

Martin Weber

Heiner Schelling

Holger Friedrich

Brigitte Gareiss

Wolfgang Steiner

Eckhard Str&ouml;fer

Dieter Schlafer

Rudi Kroner

Uwe Wegmann

Kurt Hecky

Peter Mauer

Frank Hanus

Albrecht Wilhelm Friederang

The present invention relates to a process for the preparation of an aqueous hydroxylamine solution which is essentially free of metal ions, wherein the hydroxylamine solution is subjected to at least one treatment with an acidic cation exchanger.

Method for producing aqueous hydroxylamine solutions which are substantially free of metal ions

An aqueous solution of free hydroxylamine is prepared by treating a hydroxylammonium salt with ammonia by the countercurrent method in a stripping column by a process in which hydroxylamine is liberated and at the same time the solution obtained is separated by distillation into an aqueous hydroxylamine solution and a salt fraction. The novel process can be carried out in a simple and gentle manner and on a large scale. The danger of decomposition is minimized owing to the low thermal load, the low concentration of hydroxylamine and the short residence time in the process.

Preparation of an aqueous solution of free hydroxylamine

A process for breaking down hydroxylamine in aqueous solutions, especially wastewaters, by treatment with an oxidizing agent, which comprises using as said oxidizing agent an alkali metal hypohalite or alkaline earth metal hypohalite or peroxomonosulfuric or peroxodisulfuric acid or a salt thereof and carrying out the treatment with said oxidizing agent at a pH<8.

Breaking down hydroxylamine in aqueous solutions

Fireproofed thermoplastic moulding masses

An aqueous solution of free hydroxylamine is prepared by a process in which the solution obtained by treating a hydroxylammonium salt with a base is separated into an aqueous hydroxylamine solution and a salt fraction by treatment with water or steam at .ltoreq.80.degree.0 C. The novel process can be carried out in a simple and gentle manner and on a large industrial scale. Owing to the low thermal load, the low concentration of hydroxylamine and the short residence time in the process, the risk of decomposition is minimized.

Process for production of aqueous solutions of free hydroxylamine

The present invention relates to stabilized hydroxylamine solutions comprising as stabilizer at least one compound of the formula I

Stabilized hyroxylamine solutions

A process for the regeneration of plastic diaphragms is described, in which a mineral acid solution is mixed with a suitable corrosion inhibitor, this mixture is temperature controlled at from approximately 0.degree. to 100.degree. C., preferably 40.degree. to 80.degree. C., in particular 50.degree. to 70.degree. C., and passed through the diaphragm for from approximately 0.1 to 84 hours, preferably 1 to 72 hours, in particular 2 to 24 hours.

Regeneration of plastic diaphragm

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Worms, Germany

Hans-Michael Schneider