摘要
【目的】煤矸石的高值化利用是目前研究的热点,煤矸石中高岭石的活化及作用对煤矸石的高值化利用意义重大。【方法】首先采用正交试验方法进行了煤系高岭石的热活化参数优化设计研究,再以最优条件形成的煤系偏高岭土替代部分水泥,对净浆的抗压强度、物相组成及微观结构进行了分析。【结果】试验结果表明,煤系高岭石最佳热活化条件为煅烧温度800℃,保温时间2 h,粉磨细度2.82μm.煅烧温度对煤系偏高岭土活性影响最大,粉磨细度次之,保温时间最小;采用煤系偏高岭土替代20%(质量分数)水泥,可加快水泥的水化反应速率,有效提升净浆在各养护龄期的抗压强度,其中早期强度提升最显著;微观机理分析发现,煤系偏高岭土发生火山灰反应消耗了大量氢氧化钙,形成了结构更致密的低钙硅比水化硅酸钙。
【Purposes】The high-value utilization of coal gangue has attracted attention,and the activa⁃tion and action of coal-bearing kaolin have great significance value for utilization of coal gangue.【Methods】The thermal activation parameters of kaolinite in coal gangue were optimized by orthogonal test,and the compressive strength and microstructure of paste consisting of cement and metakaolin formed under the optimal activation conditions were studied.【Findings】The experimental results show that the optimum thermal activation conditions of metakaolin are calcination temperature 800℃,holding time 2 h,and grinding fineness of 2.82μm.Calcination temperature has the greatest influence on the activity of metaka⁃olin,followed by grinding fineness and holding time.By using metakaolin instead of 20%(mass fraction)ce⁃ment,the compressive strength of cement paste at all curing ages,especially in the early age,can be im⁃proved effectively.XRD and SEM test results show that the pozzolanic reaction of metakaolin consumes a lot of calcium hydroxide,and forms calcium silicate hydrate with lower calcium-silicon ratio and denses structure.
作者
王林浩
程寅
高树峰
闫晓彦
Alfred Attoh
杨宏
WANG Linhao;CHENG Yin;GAO Shufeng;YAN Xiaoyan;ALFRED Attoh;YANG Hong(College of Civil Engineering,Taiyuan university of Technology,Taiyuan 030024,China;Shanxi Transportation Technology Research&Development Co.,Ltd,Taiyuan 030021,China;China Academy of Transportation Sciences,Beijing 100029,China;Department of Architecture,Lyuliang University,Lyvliang 033001,China;China Railway 20th Bureau Group Co.Ltd.,Lanzhou 730046,China)
出处
《太原理工大学学报》
CAS
北大核心
2024年第2期325-330,共6页
Journal of Taiyuan University of Technology
基金
山西省自然科学基金资助项目(201901D211019)。
关键词
煤系高岭石
正交试验
水泥净浆
抗压强度
煤矸石
coal-bearing kaolinite
orthogonal test
cement paste
compressive strength
coal gangue
