Recovery of High-purity Lead by Fluoboric Acid Leaching Electrolysis

Three factors influencing the desulphurization by (NH4)2CO3 and the reduction of PbO2 by Na2SO3 (solution concentration, temperature and reaction time) and two factors (voltage and reaction temperature) affecting the electrolysis recycling lead by leaching method using HBF4 under specified conditions were investigated. The results showed that the optimal processing conditions of desulphurization were 25% ammonium carbonate solution, 60 ℃ and 1 h, which could reach 97% desulphurization. When the concentration of a sodium sulfite solution was 15%, the reaction temperature was 60 ℃, the the highest deoxidize rate could reach 91%. The optimal voltage and temperature for electrolysis was 2.3 V and 40 ℃. In this condition, the purity of lead could reach 99.99%, and the current efficiency could be above 90%.