Abstract: Elongated electrically-conductive workpieces such as bars, strips and wire, are resistance heated by passing an electric current through a length of the workpiece between a pair of spaced contacts. The contacts are electrically-conductive molten metal or molten salt, the molten material being continuously circulated to move it toward and into contact with the workpiece, so that it is not necessary to bend the workpiece to immerse it in a bath of molten material. The molten material is moved against the workpiece to form an extending portion of the molten material as a contact, by projecting it as a jet, pouring it as a stream, or causing it to flow over a subjacent supporting surface.

Abstract: The invention relates to a process for the cyclic electrochemical processing of pickle waste liquors containing a maximum 100 g. of sulfuric acid and a minimum of 25 g. of iron ions per liter, combined with the pickling of iron. According to the invention the ammonium, magnesium or alkali-metal sulfate concentration of the waste liquor is adjusted to 0.5-1.0 mol./l. by introducing an appropriate salt, and the acid content of the waste liquor is reduced to a value not exceeding 100 g. of sulfuric acid/liter, then the waste liquir is fed into and passed through the cathode chambers of an electrolysis apparatus consisting of a series of dual electrolytic cells with diaphragms, whereupon the iron content of the waste liquor is reduced to a value of 7-15 g. of Fe.sup.2.sup.+ /liter, thereafter the waste liquor is fed into and passed through the anode chambers of said electrolysis equipment in parallel with the cathode flow, and a current density of 15-22 A/dm.sup.2.