National Research Development Corporation

Diamond Shamrock Corporation

British Nuclear Fuels Plc

Bush, Boake Allen Inc.

Francis Goodridge

Raymond E Plimley

Martin Fleischmann

John R Backhurst

Allen R Wright

Anthony J Montgomery

Robert P Leetham

Christopher J King

Edward J Williamson

David Garrett

Christopher J Vance

Alan R Wright

Apparatus, which can be a pulsed column, which functions as an efficient electrolytic cell having an efficient liquid-liquid extraction capability. The apparatus can comprise an anode/cathode assembly having a geometry such as to produce a substantially uniform current distribution across the cell.

Pulsed counterflow extraction column

An electrolyte containing 65 g/l zinc and 150 g/l Cu is purified in zinc, that is, the copper is removed, by causing the electrolyte to fluidize a bed 8 of 1/2 mm copper particles. The bed is fluidized by 25% to make it 42 cm deep. An anode 11 is disposed above the top of the bed. A cathode 9 is disposed part-way up the bed. Copper is electroplated onto the bed particles. Any zinc which may be electroplated onto the bed particles tends to redissolve with concomitant cementation, on the particles, of copper, which can be recovered. The electrolyte is thus eventually completely stripped of copper and can be used for zinc electrowinning. By controlling the pH of the electrolyte, substantially one metal, or one desired combination of metals, may be removed. In particular, pure copper deposition can be completed at low pH even in the presence of cadmium; upon a substantial increase in pH, cadmium deposition will occur.

Purifying mixed-cation electrolyte

An electrolyte containing 65 g/l zinc and 150 g/l Cu is purified in zinc, that is, the copper is removed, by causing the electrolyte to fluidize a bed 8 of 1/2 mm copper particles. The bed is fluidized by 25% to make it 42 cm deep. An anode 11 is disposed above the top of the bed. A cathode 9 is disposed part-way up the bed. Copper is electroplated onto the bed particles. Any zinc which may be electroplated onto the bed particles tends to redissolve with concomitant cementation, on the particles, of copper, which can be recovered. The electrolyte is thus eventually completely stripped of copper and can be used for zinc electrowinning.

Organic hydroxy compounds such as geraniol are prepared by electrochemical reduction of a corresponding substituted hydroxylamine, typically in a cell wherein the catholyte comprises a solvent and a protonating agent as well as the substituted hydoxy cycloamine and is separated from the anolyte by a membrane, the anolyte preferably containing an aqueous strong mineral acid.

Preparation of hydroxy compounds by electrochemical reduction

An electrochemical cell comprises a housing (1,2) divided by a perforated generally horizontal plate (3) into an upper chamber (4) and a lower chamber (5). Bipolar electrodes (19, 21) are disposed in the upper chamber (4) above perforations (23) in the plate (3), between electrolyte inlet and outlet weirs (11, 13) for flowing electrolyte over the plate (3). The lower chamber (5) is a gas-supply chamber for passing a gas, e.g. propylene, up through the perforations (23), so as to bubble the gas through electrolyte (e.g. NaBr solution) on the plate (3) and into the upper gas-collection chamber (4). A reactor may be formed by stacking several cells with their electrolyte flows in cascade. The cell is particularly suitable for electro-organic syntheses involving a gaseous reactant.

Electrochemical cell and process

An extended surface area electrode for an electrochemical cell is provided by causing a bed of conducting particles to be expanded in the form of a fluidized bed by controlled upward flow of electrolyte through an electrode chamber containing current-carrying conducting means which makes contact with the fluidized bed.

Electrochemical cells

Electrochemical process using a fluidized electrode

A method of carrying out an electrochemical reaction comprises setting up a fluidized bed of particles at least some of which have at least their surfaces conducting or semi-conducting, using upwardly flowing liquid electrolyte, with or without reactant liquid, for the purpose, and applying a voltage gradient across at least a portion of said fluidized bed of particles, the size of particles, the conductivity of and rate of flow of the said electrolyte and/or reactant liquid and the voltage gradient being such that not only are anodic and cathodic faces established in respect of each of some of the at least partly conducting particles but the electropotentials on said faces on substantially each bipolar particle are such that said electrochemical reaction takes place on at least some of said bipolar particles but only on one portion of the surfaces thereon of said particles. The said bipolar particles which, preferably, are spherical or cylindrical may comprise solid conducting or semi-conducting material or cores of non-conducting material with coatings of conducting or non-conducting material thereon. The said method may be, for example, the electrolysis of sea water for the production of hypochlorite or of bromide solution for the production of hypobromite or the decarboxylation of monomethyl adipate to dimethyl sebacate.

Electrochemical processes

The invention relates to electrochemical cells whereof one electrode is of a particulate type which may comprise a fluidized bed electrode, a packed bed electrode or a circulating bed electrode, an electrolyte being passed through the particulate electrode possibly for fluidizing and/or circulating the particles of the electrode. Whereas in previous cells of this kind a diaphragm has been arranged between the particulate electrode and the counterelectrode of the cell, it has been discovered that such a cell can be operated with the counterelectrode actually in contact with particles of the particulate electrode provided the material of the surface of the counterelectrode is suitably chosen. Among the materials mentioned are graphite, ruthenium oxide, lead oxide and iron oxide.

Growing community of inventors

Newcastle-upon-Tyne, United Kingdom

Francis Goodridge