| Co^(2+) ion in zinc electrolyte is deterious to the electrowinning of zinc. for it lowers the current efficiency of the electrolyte; therefore it should be removed until it`s concentration becomes tower than 1㎎/ℓ. In this experiment, a study on the precipitation of Co^(2+) ion in zinc electrolyte was carried out by using Zn-Pb alloy dust and Sb₂O₃as additives. Co^(2+) ion is precipitated by electrochemical reaction mechanism; Sb₂O₃plays an important role by acting as anodes after it is precipitated as Sb on the surface of Zn-Pb alloy dust while Zn acts as cathodes, and Pb lowers the resolving-rate of the precipitated Co. In these experiments the optimum condition of the reaction is as follows ; stirring speed : 250 rpm. temperature : 95℃, Pb content in Zn-Pb alloy dust : 1.35%, amount of Zn-Pb alloy dust : 3g/ℓ, amount of Sb₂O₃: 5㎎/ℓ, pH ; 4, and at the optimum condition, Co^(2+) ion concentration is lowered from 30㎎/ℓ to 0.2㎎/ℓ after two hours of reaction. |
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