Research And Industrial Application Of Energy Saving And Emission Reduction Technology For 420kA Pre-baked Aluminum Electrolytic Cell

In view of the current situation of high energy consumption,high resource consumption and low productivity of electrolytic aluminum industry,it has been the unremitting pursuit of development of China's aluminum industry to research and develop advanced and reliable technology,equipment technology and control technology,and acquire clean production,high-efficiency and energy-saving production technology.This paper takes 420kA aluminum electrolytic cell as the research subject,develops energy-saving and emission reduction technology and new process,and forms 420kA high-efficiency energy-saving new large pre-baked aluminum electrolytic cell technology,which provides a solid foundation for project application.Volatility of 420kA electrolytic cell physical fields,poor stability problem,through four different lining structure test cell electric field,flow field,thermal field research,developed the"efficient surface phosphorus iron cathode heat preservation technology,the uniformity of the anode current control technology",the difference between energy income and expenditure in high performance Nano insulation electrolytes is 1.6%,the Anode current deviation value 1.0 mv or less,distribution value 3.0 mv or less,the average velocity of 15.23 cm/s,compared with the plane phosphorus iron cathode electrolyzer increase current efficiency by 1.29%,reduce the power consumption of 254.35 kWh/t.Al.The high energy consumption and low efficiency of the electrolyzer are solved,and the influencing factors and rules of the stability control of 420kA pre-baked aluminum electrolyzer are revealed.In view of the high horizontal current of cathode carbon blocks and the large difference between the expansion and contraction coefficient of steel rods and multidimensional directions such as the length and width of the resistant material,a"horizontal current assembly technology for suppressing the combination of the surface cathode phosphorous pig iron and mashing paste"was developed,under the condition of cathode carbon block graphite content is 30%by two casting,the structure of the dovetail combination of new technology of casting qualification rate reached 100%,realize the level of current 1218 A/m~2,With the traditional plane cathode punch technological level current is lower 1503A/m~2 than 2721A/m~2,reduce the cathode voltage drop 60?70 mv,Reduced dc power consumption of raw aluminum from 195to 250kWh/t.Al.The engineering problems of high horizontal current of cathode carbon block and low pass rate due to small cracks are solved.Anode carbon block for aluminium electrolytic by air in the high temperature operating conditions,such as carbon dioxide,hydrogen fluoride gas oxidation corrosion caused by carbon grain loss problem such as adverse effects on the electrolytic process system,developed the anode carbon block with nano ceramic base BY-2 type high temperature resistant corrosion resistant composite coatings,500?600? temperature on the surface of the anode carbon block form dense ceramic layer,the extension of the anode carbon block cycle is 0.8 days,the anode hair consumption is 472 kg/t,the decrease is 2.22%,the net consumption is 395 kg/t,and the decrease is1.56%,The engineering application reduces the corrosion rate of the anode steel claw by 60.21%,reduce carbon emissions of 39.35 kg/t.Al.It solves the engineering problem of carbon anode oxidation corrosion,and plays a good role in protecting carbon anode.Through the integrated application of innovative technology,a complete advanced process manufacturing of large pre-baked aluminum electrolytes is formed.The research results were applied to the 420kA 300,000 tons/year"high energy efficiency,low power consumption"electrolytic aluminum green and low-carbon demonstration line,133 electrolytes achieved the original aluminum production alternating current power consumption of 12765kWh/t.Al,and 39 electrolytes achieved the original aluminum production alternating current power consumption of 12710kWh/t.Al,It is better than the original aluminum consumption of the electrolytic aluminum"leader"released by the Ministry of Industry and Information Technology in 2017,which is12817kWh/t.Al,which reduces the anode hair consumption by 10.73 kg/t,reduces carbon emissions by 39.35 kg/t.Al,and reduces the iron content brought in by steel claws.143 ppm/t.Al,saving 3219 tons of carbon blocks per year,reduce carbon emissions by 11804 tons/year.This paper studies and realizes the breakthrough of key core technologies of energy saving,emission reduction and cleaner production in electrolytes.