Imperial Chemical Industries Limited

Robin A Woolhouse

Peter J Smith

Janusz J Krause

Brian K Revill

Rowland Kennington

Keith G Moss

Electrolytic cell and electrode therefor

A method of producing an ion-exchange membrane suitable for use in an electrolytic cell in which the membrane is expanded by stretching at elevated temperature to increase the surface area per unit weight of the membrane. The membrane may be annealed at elevated temperature, and may be cooled while restrained in the expanded state. The membrane when used in an electrolytic cell remains taut and unwrinkled and leads to reduced voltage operation of the cell.

Production of stretched ion-exchange membrane

Treating a sheet of ion-exchange membrane in order to decrease the voltage of operation of an electrolytic cell containing the membrane by swelling the membrane in a liquid medium, the extent of swelling on the anode side being greater than the extent of swelling on the cathode side, and the extent of swelling on the anode side being greater than that effected by contacting the membrane with the electrolyte to be electrolyzed.

Treatment of ion-exchange membrane

An electrode, suitable for use in an electrolytic cell of the filter-press type, and comprising a substantially planar support member and on at least one face of the support member, and preferably on both faces, a plurality of elongated members, for example strips, substantially parallel to each other and each attached at both ends to the support member, a substantial part of the elongated members lying in a plane displaced from and substantially parallel to the support member and the faces of the elongated members lying in planes substantially parallel to the plane of the support member. Also an electrolytic cell, incorporating the electrode.

Electrode for use in electrolytic cell

A process for the preparation of a fire-extinguishing composition comprising a compound having an empirical formula MC.sub.2 N.sub.2 H.sub.3 O.sub.3, where M is potassium or sodium, by reacting a mixture of urea and an alkali selected from hydroxides and carbonic salts of potassium or sodium, the process comprising adding solid particulate urea, or urea and alkali in solid particulate form, to an agitated bed of solid particulate material, the bed of particulate material being heated to a temperature in the range 95.degree. to 200.degree. C and comprising at least alkali in the case where urea alone is added, and the rate of addition of the urea, or of the urea and alkali, being controlled to maintain the bed in a solid particulate form.

Growing community of inventors

Nantwich, United Kingdom

Robin A Woolhouse