Abstract: Sludge formation is reduced in the continuous production of iron by electrolysis of a ferrous electrolyte in a electrodeposition cell by cooling spent electrolyte returning to a holding or regeneration tank, and heating reconstituted electrolyte returning to the electrode-position cell. By reducing the temperature of the spent electrolyte the rate of hydrolysis of ferric ions to form oxides of iron, called sludge, is reduced, thus increasing the interval between periodic cleaning of the electrolyte regeneration system and the electrodeposition cell. In preferred forms of the invention heat energy is transferred from the spent electrolyte to the reconstituted electrolyte by means of at least one counter flow heat exchanger in the form of a hollow cylinder containing a plurality of tubes made of titanium. There may be a controllable cooling device disposed between the holding tank and the or the last heat exchanger for maintaining the temperature of electrolyte in the holding tank at a selected value.

Abstract: An electrical connection for coupling large currents (of the order of 30,000 Amps) to a rotating shaft (such as the support spindle of a drum cathode in an electrodeposition apparatus) with lower power loss as compared with conventional brush techniques. A conductive stationary member encircles an outer conductive sleeve which is locked via a taper split inner conductive sleeve to the shaft. The inner surface of the stationary member has an annular recess which forms an annular chamber. Conductive liquid fed from a reservoir mounted on the stationary member fills the chamber and electrically connects the stationary member to the outer sleeve which is electrically connected to the shaft via the inner sleeve. The stationary member has means for connection to a supply of electrical current.