Process for the recovery of metals from the scrap from nickel-cadmium electric storage batteries

Abstract

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.

Dependencies are inferred from the claim text.