Abstract: A method for electric refining of lead with alternating current in which the basic stage of the process is preceded by two stages, a preparatory stage and an initial stage. The preparatory stage involves pretreatment of the electrode surfaces by means of alternating current of equal width and amplitude of the forward and reverse pulses. During the initial stage there is effected an electric refining with alternating current having reduced current density.A circuit for electric refining of lead with alternating current has two controllable current rectifiers, each of which is connected to a separate group of electrolytic baths. The groups of electrolytic baths and the controllable current rectifiers are connected in series and opposite to one another.

Abstract: Apparatus for mechanically separating cathode metal such as zinc from a matrix during electroextraction of the metal. The matrix with layers of cathode metal on both sides thereof is supported on a frame and positioned by guides. Vacuum heads are advanced towards each other and brought into sealing contact with the layers of cathode metal on the opposite sides of the matrix. Following this, the vacuum heads are subjected to reduced pressure so that the heads effect seals with the cathode metal layers, and then the vacuum heads are pulled apart to strip the layers of cathode metal from the matrix.