Liquid metal pump and apparatus for use in cleaning and recycling solder

Apparatus for use in cleaning and recycling solder from a reservoir containing solder used in an automatic soldering plant for making electrical connections in the manufacture of electrical devices, which apparatus comprises at least one treatment tank, a first flow pipe coupling the treatment tank to a pump for liquid metal, a second flow pipe for coupling the pump to the reservoir, heating means and cooling means for the treatment tank, the pump comprising a magnet, a pipe positioned between pole pieces of the magnet so that the magnetic field extends transversely through the interior of the pipe, and means for coupling a supply of electric current to be carried in the direction transverse to both the longitudinal axis of the pipe and the said magnetic field through liquid metal contained, during use of the pump, in the pipe and exposed to the said transverse magnetic field, whereby the resultant electromagnetic force pumps the liquid metal through the pipe.