Same-slot Bipolar Manganese Electrowinning Clean Energy-saving Process

In order to solve the problems of large electric energy consumption,low productivity,acid pollution,etc.in the traditional electrodeposited manganese or manganese dioxide process,as early as the 1970s,foreign researchers had combined manganese and manganese dioxide electrolysis processes.Related research on electrolysis reports that the same tank electrolysis can overcome the high energy consumption problem of manganese or manganese dioxide alone in electrolysis.The traditional industrial diaphragm has poor liquid permeability,heat resistance and oxidation resistance,and has a short service life and needs frequent replacement.Ion exchange membranes have been used in domestic and foreign countries to replace traditional physical membranes,and the current efficiency of products prepared by ion exchange membranes is generally higher than that of physical membranes.Based on the ion exchange membrane,combined with the characteristics of electrolytic manganese and manganese dioxide,the traditional single-film double-chamber electrodeposition process was replaced by a double-membrane three-chamber process using the selective permeability of anion-cation membrane exchange membrane.Using MnSO₄ as the main salt for electrolysis,on the basis of ion exchange membrane,the same trough bipolar manganese electrowinning production process was studied,theoretical analysis and experimental simulation were carried out,the production equipment was improved and improved,and different experimental conditions were explored to achieve precise control parameters.Improve hydraulic conditions,reduce energy consumption,increase electrowinning efficiency,and add different additives to improve the quality of electrodeposited manganese.It can reduce energy consumption and increase production efficiency.The sulphuric acid is selectively permeable through the choice of anion and cation on both sides of the intermediate compartment,thereby reducing the acid pollution caused by waste acid.Multi-factor and multi-gradient experiments were designed to determine the economically reasonable operating conditions and the most significant factors affecting the quality of manganese and manganese dioxide.And to explore the various factors affecting the technical indicators,to obtain better electrolysis conditions,to achieve the goal of achieving higher production capacity through the lowest energy consumption,and at the same time can solve the environmental pollution caused by acid pollution.A single factor test is used to obtain a reasonable range of factors.Lower Mn²⁺concentration is prone to manganese depletion and lower current efficiency.Excessive Mn²⁺concentration tends to produce Mn?OH?₂ precipitation,and cathode Mn²⁺concentration is 30g/L-40g/L,the anode is about 40g/L;too high current density will affect the selective permeability of the membrane,the anode is prone to side reactions,oxygen evolution rate increases,too low energy consumption and tank voltage rise high,acid recovery is reduced.The cathode current density is 300A/m²-350A/m²,and the anode is in the range of 900A/m².The concentration of cathode buffer?NH₄?₂SO₄ and the concentration of seleno additive are too high and too low,which is not conducive to the precipitation of manganese.?NH₄?₂SO₄concentration is 100g/L-110g/L,SeO₂ concentration is 0.03g/L;too low temperature will reduce current efficiency,over temperature will increase anodic oxygen evolution rate,prone to side reaction,manganese dioxide grain agglomeration severe,prone to cracks,manganese plate blackening is serious,therefore,the temperature is around 35?;the sulphuric acid concentration of the anolyte is too low is not conducive to the tank voltage and energy consumption,excessively high amount of H⁺in the electrolyte will inhibit the main reaction The rate of formation of manganese dioxide is slowed down and the current efficiency is lowered.Therefore,the concentration of H₂SO₄ is preferably from 2 mol/L to 2.5 mol/L.The optimum process parameters were determined by orthogonal test:cathode Mn²⁺concentration was 35g/L,cathode current density was 300A/m²,cathode?NH₄?₂SO₄concentration was 90g/L,anode Mn²⁺concentration was 40g/L,anode current The density was 1050A/m²,the anode H₂SO₄ concentration was 2.5mol/L,and the electrolysis temperature was 40?.Under the optimal process parameters,the cathode current efficiency is 61.7%,the cathode energy consumption is 8539kWh·t^-1,the anode current efficiency is60.3%,the cathode energy consumption is 5522kWh·t^-1,and the sulfuric acid recovery rate is29.8%.The voltage is 5.4V.Through a large amount of data,the paper analyzes the superiority of the double-membrane three-chamber process in the same tank of electrolytic manganese and manganese dioxide,and through the lateral test with the single-film double chamber,demonstrates that the double-film three-chamber process is energy-saving,environmentally friendly and economical.It is superior to single membrane double chamber,which effectively reduces the harm caused by acid pollution to the surrounding environment and air,and the recovered sulfuric acid can be recycled.At present,the research of this subject is limited to small-scale simulation and theoretical analysis of the laboratory.It is in the preliminary exploration stage.Later,based on this,the device can be improved,the operating conditions can be optimized,and the same-channel bipolar manganese electrowinning technology can be put into actual production and large-scale.Industrial applications.