皖北煤矸石在水泥生产过程中大掺量综合利用

发布时间：2018-05-28 17:03

  本文选题：煤矸石 + 高岭石　； 参考：《安徽建筑大学》2015年硕士论文

【摘要】：煤矸石是指煤矿在开采中排出的含碳岩石。目前我国煤矸石已累计堆存45亿吨,约占全国工业废渣的25%,且每年以3~4亿吨的速度增长。仅两淮矿区煤矸石就达到1亿吨,约占安徽省固体废弃物总排放量的40%。煤矸石长期堆存占用土地,污染大气和地下水,对环境造成立体污染,矸石山的自燃、泥石流等严重危及人们的生命和财产安全。因此加强煤矸石资源综合利用迫在眉睫。本文对皖北地区煤矸石在胶凝材料方面的综合利用进行试验研究。采用荧光分析、X-ray衍射分析、扫描电镜、核磁共振分析煤矸石矿物组成、化学组成、微观形貌等;通过机械活化、热活化和化学活化对煤矸石进行活性激发;综合考虑煅烧温度、保温时间、物料粒度对煤矸石活性的影响,设计正交试验;将活化煤矸石掺入水泥中验证煤矸石活性;利用活化煤矸石代替水泥熟料制备低熟料硅酸盐水泥,探索活化煤矸石、石膏、矿渣、生石灰掺量对水泥熟料-石膏体系的影响;寻找配制满足物理力学性能的低熟料复合硅酸盐水泥优化配比;比较原状煤矸石、活化煤矸石、煤渣掺入水泥熟料-石膏体系对胶凝性能的影响。研究表明:煤矸石主要化学组成为氧化硅和氧化铝,主要矿物组成为高岭石,属粘土岩质矸石。该煤矸石活化条件为煅烧温度700℃、保温时间1h、颗粒粒径小于0.08mm。利用活化煤矸石配制的水泥满足复合硅酸盐水泥标准要求,且后期强度发展较高。配比为活化煤矸石30%、矿渣10%所得复合硅酸盐水泥,3天抗压强度可达13.2MPa,28天抗压强度可达到40.7MPa;引入外加剂后,早期抗压强度增大,当配比为外加剂0.7%、煤矸石30%、矿渣10%时,所得复合硅酸盐水泥3天抗压强度可达17.0MPa,28天抗压强度可达40.1MPa;均满足复合硅酸盐32.5水泥力学性能要求。相同掺量的活化煤矸石与煤渣制备的水泥,后者强度高于前者,所以煤渣活性更高。经扫描电镜观察,所配制低熟料硅酸盐水泥早期水化产物中絮状C-S-H凝胶和柱状晶体较少,后期随着水化反应进行生成的絮状C-S-H凝胶增多,因而水泥胶凝性能提高;对原状和煅烧煤矸石进行核磁共振分析可知,经高温煅烧的煤矸石29Si NMR谱向高场移动,高岭石晶体结构被逐渐破坏,生成偏高岭石、氧化硅及氧化铝。该课题促进煤矸石综合利用研究进展,为配制煤矸石复合硅酸盐水泥提供理论基础。
[Abstract]:Coal gangue is the carbonaceous rock discharged from coal mining. At present, 4.5 billion tons of coal gangue have been accumulated in our country, accounting for 25% of the industrial waste residue in China, and increasing at the rate of 3 ~ 4 billion tons every year. Coal gangue in Lianghuai mining area alone reached 100 million tons, accounting for 40% of the total discharge of solid waste in Anhui Province. For a long time, coal gangue deposits and occupies land, pollutes atmosphere and groundwater, causes three-dimensional pollution to environment, spontaneous combustion of gangue mountain, debris flow and so on, seriously endangers people's life and property safety. Therefore, it is urgent to strengthen the comprehensive utilization of coal gangue resources. In this paper, the comprehensive utilization of coal gangue in the cementitious material is studied. Fluorescence analysis X-ray diffraction analysis, scanning electron microscope, nuclear magnetic resonance analysis of coal gangue mineral composition, chemical composition, micro-morphology, through mechanical activation, thermal activation and chemical activation of coal gangue activation, comprehensive consideration of calcination temperature, The influence of heat preservation time and particle size on the activity of coal gangue is studied by orthogonal design; the activity of coal gangue is verified by adding activated coal gangue into cement; the low clinker Portland cement is prepared by using activated coal gangue instead of cement clinker to explore the activation of coal gangue. The effect of gypsum, slag and quicklime content on cement clinker-gypsum system; to find out the optimum ratio of low clinker composite Portland cement to meet physical and mechanical properties; to compare raw coal gangue, activate coal gangue, Effect of coal slag on cement clinker-gypsum system. The results show that the main chemical composition of coal gangue is silica and alumina, and the main mineral composition is kaolinite, which belongs to clay rock gangue. The activation conditions of coal gangue are calcination temperature 700 鈩，

本文编号：1947497