Electrowinning anodes which rapidly produce a protective oxide coating

An anode for use in zinc electrowinning is described. The anode is made of a lead-silver alloy which has been cast as a billet rolled and subjected to heat treatment either during or after rolling. The temperature of treatment is high enough to cause recrystallization of the alloy and to prevent precipitation of any alloying elements. The anode has a surface grain structure which facilitates rapid oxidation of the anode to condition the anode. The anode preferably contains at least 0.03 to 0.45% silver and Lip to 0.08% calcium.