Sab Nife Ab

Ake L Melin

Vide H Svensson

The invention relates to a method of recovering nickel from a spent fat hardening catalyst which consists of finely divided nickel metal on a carrier for example of infusorial earth and/or synthetic material and suspended in fat. The fat is saponified by means of an alkali solution to form a dissolved soap composition which is separated from the nickel metal and the carrier. The nickel metal is then leached out from the carrier and recovered in the form of nickel sulphate. Soap can be salted out of the dissolved soap composition and be used for cleaning purposes in industry, and the carrier can be washed and re-used. During the recovery waste solutions from the alkaline accumulator industry may appropriately be used so that only sulphuric acid is needed as a process chemical. The nickel sulphate solution recovered can be used, for example, as a raw material for the production of active nickel hydroxide mass for alkaline accumulators.

Method of recovering nickel from a spent fat hardening catalyst

The present invention relates to a process for the recovery of metals from the scrap from nickel-cadmium electric storage batteries or other products which in addition to cadmium also contain organic substances and metallic components made of iron, nickel or other metals. The process involves opening the batteries and emptying them of any free electrolyte, drying the scrap, removing the organic substances by pyrolysis at an initial temperature followed by condensation. The pyrolysis and distilling-off operations are performed in one and the same furnace by the successive and preprogrammed raising of the temperature inside the furnace, for example in stages, in order to produce a residue inside the furnace in the form of nickel and iron scrap. Pyrolysis takes place in a controlled atmosphere, requiring the introduction of an inert gas such as nitrogen with the addition of between 3 and 12% of oxygen, if necessary in the form of air. Pyrolysis is made to occur by raising the temperature inside the furnace from about 100.degree. C. to an initial temperature of about 400.degree. C. or 500.degree. C. The vaporization of the cadmium takes place at a second temperature of up to about 900.degree. C. in the presence of a reducing protective gas. The cadmium vapor is condensed and the liquid metal is cast into cadmium rods.

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Oskarshamn, Sweden

Ake L Melin