Pulse Regulate And Application Of Nonlinear Dynamic Mechanism Of Industrial Electrolytic Manganese

As an important additive of stainless steel,manganese is mainly produced by wet electrolysis.China's electrolytic manganese production capacity is leading in the world.However,the electrolysis process is carried out under the conditions of high concentration,high current and open-flow,which is far away from the equilibrium state.Partial discharge and turbulence along the edge of the electrode plate will strengthen the nonlinear dynamic characteristics of the coupling of reaction flow and mass transfer flow,resulting in the emergence of non-equilibrium dissipative structures such as electrochemical oscillation and fractal growth,and then facing the problems of high-power consumption,high emission and low added value for a long time.At present,pulse electrolysis has been applied to hydrometallurgical process to reduce energy consumption,reduce by-products and optimize product structure.However,the mechanism of the nonlinear reaction mass transfer coupling dynamics of externally controlled electric pulse with dissipative structures such as electrochemical oscillation and fractal growth on cathode product structure and energy consumption of electrolysis is not clear.Therefore,the research and control of nonlinear reaction and mass transfer coupling dynamics in pulse electrolysis is of great significance for further optimizing the structure of electrolysis products and technological innovation of energy saving and emission reduction.In this work,a new nonlinear dynamic model of interface reaction-flow and mass transfer flow coupling was established for the non-equilibrium nonlinear self-organization behavior of anode electrochemical oscillation and cathode dendrite fractal growth in electrolysis process.The dynamic correlation between external pulse strengthening and internal self-organization behavior was revealed,and a series of new electric pulses and reactions were designed.Besides,the energy consumption of non-linear oscillation and the behavior of cross-scale self-assembly are controlled.On this basis,on the one hand,a new method of energy saving and emission reduction and product structure optimization was developed for strengthening the resource chemical process;on the other hand,a series of high value-added new energy materials were prepared according to the structural characteristics of metal fractal materials.(1)In view of the electrochemical oscillation of anode,based on the dissipative structure theory,a new system nonlinear dynamic equation was established,and then proposed a new mechanism of pulse electric field regulating the electrochemical oscillation in the anode region of electrolytic manganese.On this basis,a new method of energy saving and emission reduction in the electrolytic process based on oscillation regulation was developed.Firstly,the influence of pulse parameters on the electrochemical oscillation inside the anode and the dissipation and regeneration mechanism of the anode self oscillation behavior during the single pulse period were studied.Secondly,the change of electrode potential during the oxidation and reduction process of manganese oxide electrode was studied,which revealed that the key of pulse electro-control was the dynamic relaxation of the binding dissociation of Mn(III)ion and peroxide.Then,a new system of nonlinear dynamic equations was established to explain the coupling mechanism of pulse electric field regulating the electrochemical oscillation of electrolytic manganese anode under high current.The results showed that the relative power consumption was reduced by 14.6%,which greatly reduces the energy consumption of electrolytic manganese.Therefore,it provides an effective way for energy saving and emission reduction of electrolytic manganese.(2)In view of the fractal growth of cathode dendrites,a new nonlinear dynamic model of coupling reaction flow and mass transfer flow was established.The influence of ion mass transfer on the fractal growth behavior of cathode dendrites was revealed.Then,pulse regulation technology of fractal electrodeposition process was developed to realize the regulation of cross-scale self-assembly behavior.The research first investigated the influence of constant current electrolysis and pulse electrolysis on the fractal growth behavior of cathode dendrites in uniform flow field.Compared with constant current electrolysis,the fractal dimension of cathode manganese dendrites obtained by pulse electrolysis is reduced by 10.4%and dendrite height is reduced by 3times.Secondly,the influence of different pulse parameters on the fractal growth behavior of cathode dendrite was investigated.It was found that when the pulse frequency was 200 Hz and the pulse duty ratio was 1:3,the fractal dimension and growth height of manganese dendrite were the smallest,which were 1.3792 and 0.10,respectively.The results show that the fractal dimension of cathode dendrite decreases by 15.4%at most;then,based on the pulse control process,Matlab is established to simulate the control process,and the simulation results are consistent with the experimental results.Then the influence of mass transfer process on the fractal growth behavior of cathode dendrite was further investigated by introducing the flow field,and it is revealed that the control of mass transfer process was the key to affect the fractal growth behavior of cathode dendrite.Finally,the fractal defects of manganese metal products were effectively suppressed and the electrolysis efficiency was improved by pulse-controlled fractal electrodeposition process enhancement technology.(3)Based on the new process intensification method of curved surface cross scale assembly,by designing different micro electric reactors and adjusting the electric field parameters,metal functional structures with high specific surface area,high conductivity and photo antireflection effect were grown on fiber and mesh substrates.The flexible electrode substrate material with fractal array structure was developed,which was successfully applied to photocatalysis and photo thermal conversion.On the one hand,high performance algal like photoelectrode based on fractal structure substrate was prepared and applied to photocatalysis.In this study,the graphite carbon nitride(g-C₃N₄)photocatalyst was coated on the surface of metal fractal array structure by electrophoretic method,and then the loading process was optimized to form algae-like photoelectrode.Finally,the fiber-shaped dye-sensitized solar cells were woven into algae-like photoelectrode to form a self driving continuous hydrogen production network.The results show that the photocurrent of alga like photoelectrode based on fractal array structure is nearly 380 times higher than that of flat-type photoelectrode based on FTO,and the hydrogen evolution rate can reach 357.7?mol?h^-1,which also has good mechanical and chemical stability.On the other hand,blanket-like solar photothermal evaporator with high performance was prepared based on fractal structure substrate and applied to photothermal transformation.In this study,nano WO_2.72 photothermal conversion material was coated on the surface of metal fractal array structure by electrophoresis method,and the loading process was optimized to form a blanket-like solar photothermal evaporator.In addition,the temperature,efficiency,flexibility and stability of the blanket-like solar thermal evaporator were tested.The results show that the surface temperature of the blanket-like thermal evaporator can reach above 100?in 5 minutes under one sunlight,the water evaporation rate is greater than 1.46 kg?m^-2?h^-1,and the conversion efficiency is 92.8%.Besides,high flexibility of the blanket-like thermal evaporator ensures its operated normally under bending and pressure environment.