Studies On Interelectrode Short Circuit Behavior Of Copper Electrorefining

In the process of copper electrorefining,the current efficiency is an important factor determining the production efficiency of copper,and is also an important index concerned by the production enterprises.interelectrode short-circuit is a common fault in copper electrolysis process and is the main factor of reducing current efficiency.At present,enterprises have adopted many methods to monitor the status change of copper electrolytic cells,but these methods all have some defects.The new short-circuit diagnosis system of copper electrolytic cells needs more accurate monitoring of electrode health and rapid response to short circuit fault.In this paper,optical fiber current sensor and K-thermocouple are used to monitor the cathode current and temperature respectively and analyze the characteristics of their changes,which lays a foundation for the establishment of the rapid diagnostic system for short-circuit in industrial copper electrorefining.Fiber optic current sensor and "re-short circuit" method are used to measure the cathode current in several copper production enterprises.The complex background magnetic field interference is effectively avoided,and the complete cathode short circuit current curve is obtained.It is found that the short circuit current curve changes in stages.Based on the analysis of the focus area of the short-circuit current curve,a rapid diagnostic method for short-circuit based on the linear fitting slope and standard deviation of the cathode current curve is proposed,and the applicable scope of the method is given.The temperature at the short-circuited cathode collector bars and the electrode around the short-circuited cathode are measured.The relationship between short circuit current and temperature was investigated by building a simulation model of the cathode collector bars and the cells bar.It is found that the temperature at the cathode collector bar lap position and the bottom of the cell bar are sensitive to the short circuit current,and the temperature change is caused by the change of the short-circuit current.According to the temperature change mode caused by short-circuit current,a thermocouple can be placed near the junction of cathode and cell bar,and the short circuit can be judged quickly by its temperature change trend.The simulation results show that the increase of the cell bar junction contact resistance and ambient temperature will increase the maximum short-circuit temperature of the cathode.The increase of heat transfer coefficient between conductor and air will reduce the maximum short-circuit temperature of cathode.Numerical simulation of the nodule growth process of short-circuit cathode shows that the nodal growth will increase the cathode current when the electrode is not shortcircuited.It provides a possibility for the short-circuit prevention system of copper electrorefining.