Atochem

Elf Atochem S.a.

Oxysynthese

Christian Pralus

Jean-Pierre Schirmann

Jean-Paul Chalieux

Jacky Duclaux

Jean-Claude Chassagne

The invention relates to the preparation of BF and H SO of commercial grade from boron trifluoride hydrate effluents containing organic impurities. The process consists essentially in reacting the said effluent with oleum, in recovering the gaseous boron trifluoride thereby liberated and in subjecting the sulphuric acid by-product to treatment with hydrogen peroxide and to purging with air.

Generation of boron-trifluoride and sulphuric acid from boron trifluoride hydrate

The invention relates to the production of colorless aqueous solutions of fluoboric acid from colored effluents of boron trifluoride hydrate. The process essentially consists of treating the colored effluent with an aqueous solution of HF, and then placing the solution obtained in contact with an activated carbon.

Production of aqueous solutions of fluoboric acid

The objectionable hypochlorite values, ClO.sup.- ions, contained in a solution of an alkali metal chlorate produced by the electrolysis of an aqueous solution of the corresponding chloride of the alkali metal, are effectively destroyed (consumed) without adversely affecting the valence state of the hexavalant chromium values also contained therein, by intimately contacting such chlorate solution with an effective amount of hydrogen peroxide such that the molar ratio hydrogen peroxide/hypochlorites is at least one and no greater than 3 and the molar ratio available hydrogen peroxide/hypochlorites is at least one.

Consumption of hypochlorite values contained in chlorate solutions of

The objectionable hypochlorite values, ClO.sup.- ions, contained in a solution of an alkali metal perchlorate produced by the electrolysis of an aqueous solution of the corresponding chlorate of the alkali metal, are effectively destroyed (consumed) without adversely affecting the valence state of the hexavalent chromium values also contained therein, by intimately contacting such perchlorate solution with an effective amount of hydrogen peroxide such that the molar ratio available hydrogen peroxide/hypochlorites is at least one.

Consumption of hypochlorite values contained in perchlorate solutions of

Hydrogen peroxide is produced from hydrogen and oxygen by (a) intimately contacting gaseous hydrogen at superatmospheric pressure with an inorganic aqueous reaction medium which includes a catalytically effective amount of a platinum group metal catalyst, (b) next diminishing the amount of hydrogen in the gaseous phase to a value under the explosive/flammable limits of admixture thereof with the gaseous oxygen introduced in step (c), and (c) intimately contacting and reacting the aqueous reaction medium and diminished gaseous phase with a source of gaseous oxygen.

Production of hydrogen peroxide

A process for the cyclic production of hydrogen peroxide comprising alternating the reduction of oxidation of a quinone in a solvent medium and extracting the hydrogen peroxide. The solvent medium contains a carboxylic acid amide comprising at least one aryl group to satisfy one of the following conditions:

Process for the cyclic production of hydrogen peroxide

A stabilized acidic aqueous composition comprising hydrogen peroxide, metallic ions, and 3-amino-1,2,4-triazine, said triazine being present in an amount sufficient to improve the stability of said composition against decomposition of said peroxide and the methods of utilizing such composition to treat metallic surfaces and to precipitate hydrated uranium peroxide from a solution containing uranium dissolved therein.

Stabilized acidic aqueous solutions containing hydrogen peroxide and

Process for improving the stability of aqueous solutions containing hydrogen peroxide, metal ions and hydrofluoric acid which can be partially in the form of salts, comprising adding to the said solution at least one hydroxide selected from alkali metal hydroxides, ammonium hydroxide, or mixtures thereof in an amount which is insufficient to neutralize all the acidity present. The resultant novel stabilized solutions according to the invention are used in the surface treatment of metals especially of stainless steels.

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Saint Cyr au Mont d'or, France

Christian Pralus