Nickel-cadmium storage batteries are now widely used (and predictably more so) in industrial production and everyday life. That makes their manufacturers seek new economically effective and ecologically safe means of their utilisation. Experience shows that one of the ways would be to process active material components of alkaline nickel-cadmium batteries to re-use them later. Our company’s specialists have developed a system of equipment for utilisation of pocket-plate electrodes, which makes it possible to use worked-out batteries as secondary raw material for the production of active material while causing minimal damage to the environment.

To ensure high electrochemical activity of Ni(OH)₂ and to reduce the loss of nickel-bearing raw material in the technological process we have managed to effectively separate metal part of pocket-plate oxide-nickel electrodes from anode material, using physical-mechanical methods and without admixture turning into a nickel sulphate solution. This helped to avoid chemical treatment of the solution from worked-out electrodes and process faulty electrodes, rejected on production stages, to recycle extracted anode material. This was made possible because worked-out pocket-plate oxide-nickel electrodes were deformed at the pressure of 19-45 H/mm² during 0.5-1 second, then anode material was extracted and leached with sulphuric acid solution (its strength being 200-300 g/l) at 60-80°C till ion concentration reached Ni 65-110 g/l and pH=3.5-5. The obtained nickel sulphate was then used for Ni(OH)₂ precipitation. Use factor of nickel in anode material from Ni(OH)₂, obtained by this method, was 85-98% with specific capacity of anode material being (after second cycle) 0.167-0.187A•h/g.

We have carried out research which helped to develop an uninterrupted process of distilling Cd_MET from waste products in storage batteries manufacturing. We have managed to create optimum conditions for Cd_MET steam condensation. Having tested the equipment we have determined the composition of materials in the furnace, most liable to be influenced by high temperature in the reducing medium. We have designed and manufactured a heating element whose improved version allows to maintain constant temperatures up to +950 °C. We have determined the optimum composition of the furnace charge, the amount of charge in a batch and the conditions of its thermal treatment, which guarantees the maximum speed of the distillation process and ensures effective metal cadmium extraction. The achieved furnace output ranges between 50 to 120 kg a day and depends on the level of cadmium in waste products used for distillation. And the actual power consumption of the furnace does not exceed about 7 kW-h. Cd_MET, obtained from waste products, was sublimated in the furnace for cadmium oxidation at 800-850°C - it was added to a retort with metal cadmium ingots at the ratio 1:4. Obtained active material was then tested for conformity with technological requirements concerning chemical composition, and it was used in manufacturing cadmium electrodes of nickel-cadmium storage batteries.