This process is similar to electro-winning, but in this case the deposited metal is Tin.
Most plants use the soluble tin Anode, whereas the insoluble activated Titanium Anode is inserted only in one or two cells, with the purpose of rebalancing the concentration of Tin in the solution, which has a tendency to increase the lower Cathode efficiency compared to the Anode.
Recently a system has been developed which uses only insoluble Anodes, while the Lead is dissolved separately in a dedicated dissolver.
Given the aggressiveness of the solution composed by methane-sulfonic (MSA) and phenol-sulfonic acid (PSA), which tends to increase the consumption speed of Iridium Oxide – and additionally the tendency to create “over-coatings” of passivating Lead Oxide on the Anodes, there was the need to design a particular coating’s formulation and a special treatment for the basic roughness which hindered the overcoating’s grip.
At CNT we offer both coating solutions, both for the MSA and PSA applications.
We build the Anodes according to our customers’ drawing or we can supply only the re-coating service on worn-out Anodes.