Effect Of Phosphorus Compounds On Electrochemical Oscillation Of Electrolytic Metal Manganese

As an indispensable additive in iron and steel industry,manganese plays an important strategic role in the industrial economy.Among the surveyed of manganese resources in China,high phosphorus manganese ore accounts for more than 49.6%.The phosphorus in the high phosphorus manganese ore entered into the product during the process of electrolytic metal manganese,which affected the electrolytic energy efficiency and the product quality.To solve the problems,many domestic and foreign researchers studied dephosphorization technologies such as magnetic separation and flotation of manganese ores,while,the effect of phosphorus on the productive process of electrolytic metal manganese has been poorly researched.The study focused on the effect of phosphates in high-phosphorus manganese ore on the process of electrolytic manganese metal.The experiment was carried out to investigate the effects of different phosphates on the electrochemical oscillation behavior of anodes under constant voltage and current conditions.Meanwhile the effect of phosphate salts on electrolysis efficiency,energy consumption,anode and cathode products were researched during electrolysis.Finally,the regulation of the external pulse power supply on the electrolysis process of high phosphorus system was analyzed,the obtained results may provide new ideas for the application of high-phosphorus manganese ore to the electrolysis process.The main contents of the reasearch were as follows:（1）The effects of different concentration of H₂PO₄^-on electrochemical oscillation of electrolytic manganese anode and electrolytic production process were investigated.With the increased of H₂PO₄^-concentration,the periodic electrochemical oscillation decreased monotonously,and the electrolytic efficiency of electrolytic manganese decreased at same time,while the energy consumption of electrolysis gradually increased.The products of electrolytic cathode were brittle and fragile and easily pulverized with the investigated of the effects of H₂PO₄^-on cathode and anode products.It was found that PO₄^3-and P₂O₇^4-were formed in the process of electrolysis.These ions reacted with free Mn²⁺ions,then attained Mn₃（PO₄）₂ and Mn₂P₂O₇.The newly produced Mn₃（PO₄）₂ and Mn₂P₂O₇ gathered around the electrode surface and covered with MnO₂,inhibiting it formation,resulting in the periodic electrochemical oscillation was inhibited in the process of electrolysis of manganese.（2）The effects of different concentrations of HPO₃^2-on the electrochemical oscillation and the electrolysis process of electrolytic manganese were investigated.With the increased of HPO₃^2-concentration,the periodic electrochemical oscillation fluctuate gradually,and the electrolytic efficiency of electrolytic manganese showed an irregular change.The effects of HPO₃^2-on cathode and anode products during electrolytic manganese were investigated.It was found that PO₄^3-was formed in the process of electrolysis.The newly produced Mn₃（PO₄）₂ and Mn₃（PO₄）₃ gathered around the electrode surface and covered with MnO₂,which resulted the non-periodic transformation in the electrochemical oscillation of the anode.（3）The influences of pulse current electrolysis conditions on the electrolytic efficiency and energy consumption of high concentration H₂PO₄^-system electrolysis manganese were investigated.It was found that the pulse electrolysis had best electrolytic effect with pulse frequency of 1000Hz,duty cycle of 50%,and average current density of 350 A/m².Compared with direct current electrolysis,pulse electrolysis could improve the efficiency by 2%and energy consumption of manganese electrolysis decreased 216.066 KW·h.