420kA预焙铝电解槽节能减排技术研究与工业应用

【作者】 杨国荣；

【导师】 朱云； 苏其军；

【作者基本信息】 昆明理工大学 ， 冶金工程（专业学位）， 2018， 硕士

【摘要】 针对制约电解铝工业高能耗、高资源消耗、生产率低等现状,研发先进可靠的工艺技术、装备技术和控制技术,获得清洁生产、高效节能的生产技术,一直是中国铝工业发展的不懈追求。论文研究以420kA铝电解试验槽为研究主体,开发出节能减排技术、新工艺,形成了420kA高效节能新型大型预焙铝电解槽技术,为工程运用提供了坚实的基础。针对420kA电解槽物理场波动大、稳定性差等问题,通过四种不同内衬结构试验电解槽电场、热场、流场平衡研究,开发出“高能效曲面磷生铁阴极保温技术、阳极电流均匀性控制技术”,高性能纳米保温材料强保温型电解槽实现能量收入与支出差额为1.6%,阳极电流偏差值≤1.0 mV、分布值≤3.0mV,平均流速15.23cm/s,与平面磷生铁阴极电解槽相比提高电流效率1.29%,降低交流电耗254.35kWh/t.Al。解决了电解槽高能耗、低效率等工程技术问题,揭示了420kA预焙铝电解槽物理场稳定性控制的影响因素及影响规律。针对阴极炭块水平电流高、磷生铁浇铸工艺存在钢棒与耐材长度、宽度等多维度方向膨胀收缩系数差异大的问题,开发出“曲面阴极磷生铁与捣固糊相结合的抑制水平电流组装技术”,在阴极炭块石墨含量30%条件下采用两点浇铸、燕尾结构炭块组合新技术浇铸合格率达到100%,实现水平电流1218 A/m~2,与传统平面阴极捣固糊工艺水平电流2721 A/m~2相比减少1503 A/m~2,降低阴极压降60~70mV,降低原铝直流电耗195~250kWh/t.Al。解决了阴极炭块水平电流高、磷生铁浇铸易产生微小裂纹致合格率低等工程技术问题。针对铝电解用阳极炭块在高温工况条件下受空气、二氧化碳、氟化氢等气体氧化腐蚀致炭粒脱落对电解工艺体系造成不利影响等问题,开发出阳极炭块用BY-2型纳米陶瓷基耐高温防腐蚀复合涂料,500~600℃温度下在阳极炭块表面形成致密陶瓷层,延长阳极炭块周期0.8天,实现阳极毛耗472kg/t、降低2.22%,净耗395kg/t、降低1.56%,工程化应用降低阳极钢爪腐蚀速率60.21%,减少碳排放39.35 kg/t.Al。解决了炭素阳极氧化腐蚀工程技术问题,对炭素阳极起到良好的保护作用。通过创新技术的集成应用,形成完整的大型预焙铝电解槽先进流程制造。研究成果应用于420kA30万吨/年“高能效、低电耗”电解铝绿色低碳示范线,133台电解槽实现原铝生产交流电耗12765kWh/t.Al,39台电解槽实现原铝生产交流电耗12710kWh/t.Al,优于国家工信部发布的2017年电解铝“领跑者”原铝交耗12817kWh/t.Al,降低阳极毛耗10.73 kg/t,减少碳排放39.35 kg/t.Al,降低钢爪带入铁含量143ppm/t.Al,节约炭块3219吨/年,减少碳排放11804吨/年。论文研究实现了电解槽节能减排、清洁生产关键核心技术的突破。更多还原

【Abstract】 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.更多还原