摘要
煅后石油焦是铝电解用炭阳极等冶金炭素材料的主要原料,现有研究缺乏对不同煅烧温度下煅后焦微观结构演变的深入探索,导致冶金炭素材料的制备难以智能调控,降耗困难。针对上述问题,本文利用一种基于高分辨适射电镜(HRTEM)检测的碳材料晶格条纹智能提取技术,结合数学拟合对不同煅烧温度下煅后焦微观结构的演变规律进行了深入探究。结果表明,煅后焦的平均晶格条纹长度、堆叠占比和45°集中分布的特征值在600℃以下会随温度升高而轻微劣化,而在600~1 600℃的温度范围内,各项微观结构特征值的变化规律符合Sigmoid函数模型,随着温度升高先迅速提升后平缓增加;利用拟合曲线的推导公式求得煅后焦各项微观结构特征的有效升温区间,进一步得到煅后焦微观结构特征随温度变化而演变的优先级为晶格取向>晶格堆叠>晶格尺寸生长;通过拉曼光谱分析得到煅后焦的石墨化度R值在25~1 600℃的温度范围内由0.86变化到0.59,石墨化度在不同温度下的变化规律映证了上述各项微观结构特征演变分析的结果。
Calcined petroleum coke is an important raw material of metallurgical carbon materials such as carbon anode for aluminum electrolysis. The existing research lacks of in-depth exploration of the microstructure evolution of calcined coke at different calcination temperatures, which makes it difficult to intelligently control and reduce the consumption of metallurgical carbon production. In order to solve the above problems, an intelligent extraction technology of lattice fringes of carbon materials based on HRTEM detection and mathematical fitting were used to investigate the evolution law of the microstructure of calcined coke at different calcination temperatures. When the temperature was below 600 ℃, the average lattice fringe length, total stacking frequency, and 45° contribution of the calcined cokes slightly deteriorated with the increase of temperature. While in the temperature range of 600 to 1 600 ℃, the variation patterns of the characteristic values were consistent with the Sigmoid function model, which increased rapidly and then gently with the increase of temperature. The effective temperature intervals of the microstructure characteristics were obtained via the deduced formula of the fitting curves. The priority of the microstructure characteristics changing with temperature was as follows: lattice orientation > lattice stacking > lattice growth. The graphitization degree R of calcined coke varied from 0.86 to 0.59 in the temperature range of 25~1 600 ℃ by Raman spectrum analysis. The evolution law of graphitization degree at different temperatures demonstrated the result of the variation patterns analysis of the above microstructure characteristics.
作者
犹子涵
肖劲
于谱生
周宇
甘小双
仲奇凡
YOU Zihan;XIAO Jin;YU Pusheng;ZHOU Yu;GAN Xiaoshuang;ZHONG Qifan(School of Metallurgy and Environment,Central South University,Changsha 410083,China;Jinan Aohai Carbon Products Co.Ltd,Jinan 250101,China)
出处
《中国有色冶金》
CAS
北大核心
2024年第1期8-16,共9页
China Nonferrous Metallurgy
基金
国家自然科学基金面上项目(52174338&52374421)
湖南省自然科学基金项目(2022JJ20086&2021JJ30796)
中南大学创新驱动项目(2023CXQD005)
云南省科技计划项目(202202AB080017)
贵州省科技计划项目([2023]General212)。
关键词
冶金炭素
煅后焦
晶格条纹
微观结构演变
铝电解
炭阳极
煅烧
metallurgical carbon
calcined coke
lattice fringe
microstructure evolution
aluminum electrolysis
carbon anode
calcination
