Solvay & Cie

Interox (societe Anonyme)

Solvay Et Cie (societe Anonyme)

Francois Dujardin

Daniel Tytgat

Marianne Reignier

Albert Degols

Nathalie Barthelemy

Guy Sluse

Process for chemical polishing of austenitic stainless steel surfaces using chemical polishing baths effective at a slow rate of reaction. The baths include in an aqueous solution a mixture of hydrochloric acid, nitric acid and phosphoric acid, an optionally substituted hydroxybenzoic acid, at least one quaternary ammonium salt and an additive chosen from perchloric acid and water-soluble salts of perchloric acid.

Baths and process for the chemical polishing of stainless steel surfaces

Baths for the chemical polishing of stainless steel surfaces containing, in aqueous solution, a mixture of hydrochloric acid, phosphoric acid, nitric acid and of sulphosal cylic acid and at least one abietic compound.

Baths and process for chemical polishing of stainless steel surfaces

Hydrogen peroxide (8) is introduced at the interface of an anode (5) and an alkaline anolyte (3) of a fuel cell containing, in addition, an acid catholyte (4), isolated from the anolyte by a separator which is permeable to ions (2).

Process for the production of electricity in a fuel cell, and fuel cell

The invention relates to a process and a device for monitoring the change in the surface condition of a metal component in an installation containing an ionic phase, by a modification of the working conditions in the installation, relative to standard working conditions. The equilibrium potential of the component in the ionic phase in the installatoin is applied to one electrode of an electrochemical measuring cell, the electrode and the cell respectively reproducing the metal component and the installation under standard working conditions, and the intensity of the resulting electric current in the measuring cell is measured. The invention applies, in particular, to the monitoring of the corrosion of the wall of a steel pipeline through which a sodium chloride brine passes.

Process and device for monitoring the change in the surface condition of

A method is disclosed for handling corrosive concentrated aqueous solutions of alkali metal hydroxides containing major amounts of alkali metal halides in equipment made of ordinary or mild steel. Corrosion is prevented by a combination of controlling the amount of alkali metal hydroxide to less than 500 gms per kilogram of solution; maintaining the temperature of the solution below 130.degree. C.; and providing an anodic potential of between -1000 mV and -200 mV with respect to the potential of the saturated calomel electrode.

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Brussels, Belgium

Francois Dujardin