| The roll-casting is different from the traditional technology of cast-rolled which is used to manufacture lead alloy anode,it combines continuous casting with rolling,and has the advantages of short flow process, low cost, high productivity. Meanwhile, imposing electromagnetic/ultrasonic compound energy-field during the roll-casting process can improve the microstructure and properties of lead alloy anode. The fluid field of lead alloy melt in nozzle cavity is the important factor influencing the roll-casting process and lead alloy anode properties. In this paper, the finite element models of nozzle cavity was created using ANSYS finite element software. Effect of different nozzle spacer sharps, different nozzle spacer positions, and different nozzle spacer structures on flow field were studied. Effect of electromagnetic/ultrasonic compound energy-field on fluid field was studied. The experiment of electromagnetic/ultrasonic compound energy-field roll-casting for producing lead alloy anode was carried out, and the influence of electromagnetic/ultrasonic compound energy-field on the electrochemical behavior of anode was studied. The results show that:The Effect of different nozzle spacer sharps, different nozzle spacer positions, and different nozzle spacer structures on flow field were studied systematically and the best nozzle is screened out. Effect of electromagnetic/ultrasonic compound energy-field on fluid field was studied. The effect of different energy-field power on flow state, velocity of flow, distribution of velocity and temperature.The simulation results show that streamline form nozzle spacer is most suitable for lead alloy roll-casting, and the optimum position of nozzle spacer is about70mm from nozzle cavity outlet. When current intensity increase5V, ultrasonic power increase100W, the velocity of flow increase0.3-0.43mm/s, the temperature increase1-2℃.The intensity increase should be in10-15A, the ultrasonic power should be in200-300W, that is good for uniform flow field and temperature field.The electrochemical behavior of compound energy-field roll-casting lead alloy anode is studied systematically and the electrochemical behavior and characteristics anode are revealed. Results show that the oxygen evolution overvoltage and corrosion rate of anode continue to decrease as the strength of compound energy-field increasing. The oxygen evolution overvoltage reduce 35mV, the corrosion rate decreases by14.3%, comparer with anode without applying compound energy-field. The EDS and CV analysis confirm that the compound energy-field make the Ag distributes more uniform, and increase electrocatalysis activity points, which is the main reason compound energy-field improves the electrochemical properties of lead alloy anode.The compound energy-field roll-casting lead alloy anode had application in zinc electrowinning for the fist time. Its’ electrochemical performance had been studied, and the result show that the oxygen evolution overvoltage and bath voltage of compound energy-field roll-casting lead alloy anode is lower, and its’ current efficiency is higher, which can reduce energy consumption8%. Besides its’ corrosion rate is lower, which prolong the anode life9.8%. |
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