Extraction of tin from sodium stannate by electrowinning
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Sodium stannate electrowinning is used to extract tin; a steel electrolytic cell is used as the anode and a stainless steel plate as the cathode. What additives are generally used, and how can dense tin be obtained instead of spongy tin?
I don’t understand what you mean by using a steel electrolytic cell as the anode; the sodium stannate electrowinning process is primarily based on an alkaline environment, with NAOH and NA2CO3 serving as additives
Sodium stannate leached from alkaline solutions is not suitable for direct electrowinning to obtain dense metallic tin, because to produce dense metallic tin it is necessary to reduce the concentration of divalent tin in the solution, so as to prevent the formation of sponge tin. To achieve this, an organic oxidant—nitrobenzene—is used in the leachate, which increases the dissolution rate of tin and results in an alkaline solution free of divalent tin.