(57) A method of electrolytic tinning of metal in strip form using an insoluble anode, comprises passing the strip (1) to be tinned through an electrolytic tinning bath (35) having an insoluble anode (5), the strip (1) forming the cathode, to deposit tin from the electrolyte onto the strip, and circulating the electrolyte through an electrolytic replenishing cell (6) outside the tinning bath for addition of tin ions in order to maintain the desired concentration of tin ions in the tinning bath. The replenishment cell has a tin anode chamber (11) with a tin anode system (27,28), a cathode chamber (12) having an insoluble cathode (25), and a membrane (13) between them substantially impermeable to tin ions. To make the replacement of the anode easier and to improve efficiency, the tin anode system of the replenishing cell comprises an insoluble tin anode (27) and a bed (28) of granular tin material which is fluidized by the electrolyte.
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