改质沥青对电煅无烟煤和沥青焦浸润性的研究

以改质沥青为粘结剂、电煅无烟煤和沥青焦为骨料,研究骨料粒度、加热温度、保温时间及振动次数对改质沥青浸润性的影响,并对不同粒度分布的电煅无烟煤和沥青焦的比表面积进行测定。结果表明,随着骨料粒度的减小,骨料颗粒的比表面积逐渐增大;改质沥青对电煅无烟煤和沥青焦的浸润性均随骨料粒度的减小和振动次数的增加而大幅度降低,随加热温度和保温时间的增加而逐渐增大。通过适当调整骨料粒度分布、加热温度、保温时间、振动次数等工艺参数,能够改善改质沥青对电煅无烟煤和沥青焦的浸润效果。     

粘结剂含量对铝电解用炭间糊性能的影响

以电煅煤、沥青焦、熟碎为骨料,改质沥青和煤焦油为粘结剂制备铝电解用炭间糊,并研究粘结剂含量对炭间糊性能的影响。结果表明,随着粘结剂含量的增加,炭间糊的挥发分增加;灰分、膨胀/收缩率先减小后增大,而体积密度、电阻率和耐压强度则是先增大后减小。当粘结剂含量为17%时炭间糊的综合性能最佳。     

颗粒级配对铝用冷捣糊材料性能的影响

以电煅煤、熟碎和沥青焦为骨料,改质沥青和煤焦油为粘结剂制备铝用冷捣糊材料。采用DingerFunk方程和容重法系统研究颗粒级配对冷捣糊性能的影响。结果表明,粒度分布系数n值为0.45时糊材料各项性能为最佳,其中体积密度为1.583g/cm3、气孔率为19.2%、电阻率为63μΩ·m、耐压强度为36.5MPa。     

电煅炉安全平稳运行的技术探讨

当今最常用的阴极炭素制品原料高温热处理设备主要是电煅炉。电煅炉使用过程中受生产工艺、设备结构性能、操作维护方式等因素的影响,其使用寿命、安全运行状况差距很大。因此,注重持续总结影响电煅炉安全平稳运行的因素并不断加以规范和创新,对优化生产工艺,促进安全生产,降低生产成本意义重大。本文针对电煅炉运行中容易出现的故障、产生原因、检查判断方法及处理措施进行了分析探讨,为保障电煅炉的安全平稳运行提供借鉴。     

改质沥青——煤焦油粘结剂添加B_4C对铝用炭间糊性能的影响

以改质沥青—煤焦油混合粘结剂为基体,添加B_4C制备改性粘结剂,并以电煅无烟煤、沥青焦、熟碎为骨料和改性粘结剂制备铝电解用炭间糊,研究B_4C添加量对制备炭间糊性能及微观结构的影响。结果表明,随着B_4C添加量的增加,制备炭间糊的灰分、电阻率、耐压强度、残炭率逐渐增大,挥发分、膨胀/收缩率、失重速率逐渐减小;B_4C在高温下与O_2、CO等小分子化合物发生化学反应,生成的氧化硼高温熔融,可以有效减缓粘结剂热解缩聚产生的体积变化和快速失重,并改善粘结焦的致密程度;当B_4C添加量为3%时,制备炭间糊具有较佳的综合性能。     

酚醛树脂炭包覆氧化微晶石墨负极材料的电化学性能研究

采用双氧水对天然微晶石墨进行表面氧化处理,并用酚醛树脂炭包覆氧化处理石墨,考察了氧化处理和包覆处理对天然微晶石墨晶体结构、形貌和电化学性能的影响。结果表明:双氧水表面氧化增加了微晶石墨表面含氧官能团,提高了微晶石墨材料的储锂容量,首次脱锂容量由321.4m Ah/g提高到350.6 m Ah/g;酚醛树脂炭包覆氧化处理石墨的首次充放电效率提高至83.9%,30次充放电循环后的容量保持率提高到92%。     

石油焦煅烧程度对铝用炭阳极显微结构及电解消耗的影响

以不同煅烧程度石油焦为骨料,煤沥青为黏结剂制备铝用低煅焦炭阳极.通过激光共聚焦扫描显微镜和图像分析方法对炭阳极孔隙结构进行分析表征,并考察阳极反应性和电解消耗性能.在煅后焦微晶尺寸1.7~2.7 nm范围内降低石油焦煅烧程度,炭阳极小孔隙逐渐沿骨料-黏结剂界面演变为裂纹状大孔隙,炭阳极孔隙率、形状因子及连通率均先减小后增大,视孔隙比表面积呈减小趋势.煅后焦微晶尺寸降低至1.9 nm较为适宜,对应的炭阳极空气和CO₂反应质量损失率最少为9.6%和3.0%,每吨铝阳极碳耗为355.4 kg.低煅焦炭阳极过量消耗机制从以黏结剂选择性消耗转变为骨料与黏结剂共同消耗,使碳渣量减少.      

废阳极生产高石墨质阴极炭块新工艺

本项目开发了新的铝电解槽炭质内衬材料，采用废预焙阳极炭块为原料，利用快速石墨化的生产技术生产废阳极石墨碎，使用废阳极石墨碎、电煅煤和中温沥青等原料生产高石墨质阴极炭块。项目关键技术和创新点：     

改质沥青对冶金炼焦过程单种煤成焦性质的影响

 针对宣化钢铁公司焦化厂所用的种煤,分别研究改质沥青的加入量,对灰分Ad、挥发分Vdaf、硫分St,d、收缩指数X和煤粘结指数G等主要成焦性能的影响。研究表明：加入改质沥青小于5％时,对瘦煤、1/3焦煤、焦2煤和弱粘煤的灰分、硫含量的影响不大,对弱粘煤、1/3焦煤和瘦煤的粘结指数没有明显的影响,对弱粘煤和瘦煤的胶质层厚度影响也不明显;随着改质沥青的加入,焦2煤和1/3焦煤的胶质层厚度显著增加,焦2煤的粘结性指数也显著增加。加入改质沥青大于5％时,随着改质沥青的加入,瘦煤和弱粘煤的灰分下降明显,焦2煤硫含量降低增大,瘦煤的胶质层厚度显著增加,弱粘煤、1/3焦煤和瘦煤的粘结指数有明显增加。加入改质沥青对各单种煤收缩指数影响规律较复杂,弱粘煤和1/3焦煤的收缩指数在配入3%改质沥青降到最小,以后又都明显增大,但改质沥青达到5%~6%后又减小;焦2煤和瘦煤在加入量小于5％时,收缩指数变化不大,加入量大于5％时才明显减少。     

微孔模压小炭块的开发与应用

根据高炉炉底炉缸的破损机理,选用优质电煅烧无烟煤为主要原料,煤沥青或沥青和酚醛树脂为粘接剂,并加入特殊添加剂,采用高压模压成型、高温 烧成、精磨加工工艺生产的微孔模压小炭块具有优良的理化性能。中小型高炉使用微孔模压小炭块,有望解决炉底炉缸大炭块“环状断裂”和“蒜头状”异常侵蚀问题,可使高炉一代寿命达到10－15年。     

Effect of anthracite properties and formulation on properties of bench scale cathode blocks for aluminum smelting

Bench scale cathode blocks for aluminum smelting having an aggregate of 70 pct anthracite calcined at 1135°C—30 pct ball milled graphite and a coal tar pitch binder were fabricated, baked at 1135°C, and tested for electrical resistivity and expansion during electrolysis in a test cell. Twelve anthracite samples, for which a number of chemical and physical properties were determined, were used in cathode fabrication so that relationships among anthracite properties and cathode properties could be determined. Cathode expansion during electrolysis increased with increasing sulfur content of the anthracite but appeared to decrease with increasing silicon content. Electrical resistivity decreased with an increase in the fraction of green anthracite exhibiting a conchoidal rather than laminar fracture. With the finer of two anthracite aggregate sizings used, both cathode expansion during electrolysis and electrical resistivity decreased sharply as binder content was increased from 16 to 22 pct. Baked apparent density also increased at the same time but was not,per se, a valid indicator of either electrical resistivity or expansion during electrolysis; cathodes produced using a coarser anthracite sizing, which resulted in higher baked apparent densities, had higher electrical resistivities and expansions during electrolysis. Electrical resistance of all cathodes increased during electrolysis in the test cell by an amount proportional to the amount of expansion.     

粒度细化对煅后焦粉料体积密度的影响

考察了煅后焦粒度细化对体积密度的影响。结果表明,在现有生产原料和配方条件下,焦炭粗粒配比从14.4%减少到8.4%区间时,体积密度从1.134g/cm3逐渐增加到1.159g/cm3,是体积密度可用的调整空间;不宜通过减少焦炭中粒来提高体积密度;通过减少焦炭细粒含量,可有效提高体积密度。     

Effects of Coke and Formulation Variables on Fracture of Bench Scale Prebaked Anodes for Aluminum Smelting

Bench scale anodes were prepared using a number of calcined cokes, aggregate sizings, and pitch levels and tested for thermal shock resistance and flexural strength. Thermal shock resistance rose with increasing coke real density, while flexural strength tended to improve with increasing coke bulk density. With coarser aggregate sizings, a pitch level resulting in maximum baked apparent density maximized thermal shock resistance and flexural strength. With a finer aggregate sizing, thermal shock resistance and flexural strength peaked at a pitch level greater than that producing the highest baked apparent density, so maximum values require more pitch than probably practical for full-size anodes.     

Effects of anthracite calcination and formulation variables on properties of bench scale aluminum smelting cell cathodes

Several anthracites were calcined at temperatures ranging from about 1100 to 2300°C and bench scale cathodes fabricated, baked, and tested for electrical resistivity and expansion during electrolysis. Cathode electrical resistivity did not decrease much with increasing anthracite calcination temperature to about 1800°C but decreased sharply thereafter. Cathode expansion during electrolysis was inversely proportional to anthracite calcination temperature to about 2000°C. Electrical resistivity generally decreased during test cell operation. A correlation between anthracite properties and cathode properties for anthracites calcined at 2100°C could not be made. With a commercial electrically calcined anthracite, the finer of two aggregate sizings resulted in cathodes with superior properties, and properties generally optimized at a binder level producing about a zero volume change during baking.     

Effects of anthracite calcination and formulation variables on properties of bench scale aluminum smelting cell cathodes

Several anthracites were calcined at temperatures ranging from about 1100 to 2300°C and bench scale cathodes fabricated, baked, and tested for electrical resistivity and expansion during electrolysis. Cathode electrical resistivity did not decrease much with increasing anthracite calcination temperature to about 1800°C but decreased sharply there-after. Cathode expansion during electrolysis was inversely proportional to anthracite calcination temperature to about 2000°C. Electrical resistivity generally decreased during test cell operation. A correlation between anthracite properties and cathode properties for anthracites calcined at 2100°C could not be made. With a commercial electrically calcined anthracite, the finer of two aggregate sizings resulted in cathodes with superior properties, and properties generally optimized at a binder level producing about a zero volume change during baking.