泡沫凝胶法制备轻质煤矸石多孔材料研究

发布时间：2018-06-24 22:14

本文选题：煤矸石 + 硅溶胶　；参考：《湖南科技大学》2015年硕士论文

【摘要】：煤矸石是我国规模最大的工业固体废弃物之一,它对环境的负面影响问题越来越严重。我国现有的煤矸石利用途径大多表现出利用附加值较低、利用率低等问题,采用高效环保的方法制备无机功能材料是提高煤矸石的附加值和利用率的关键技术。本论文以资兴矿务局周源山煤矿煤矸石为原料、以硅溶胶为胶凝剂,通过泡沫凝胶法制备出密度为0.6~1.2 g/cm3的煤矸石轻质多孔材料。首先,本论文对周源山煤矸石进行化学成分分析后得出该煤矸石主要含有SiO2和Al2O3,硫含量仅为0.11%,对其进行矿物成分分析得出该煤矸石主要含有石英和高岭石,属于粘土类矸石;对煤矸石进行球磨和筛分,结果表明筛分粒径随球磨时间的延长而逐渐降低,在球磨20 min后过28目筛得到的筛下料平均粒径为77.65μm的煤矸石粉体,并以此粉体为原料制备煤矸石多孔材料。其次,探索了煤矸石料浆水固比、胶凝剂的加入量、促凝剂的加入量、发泡剂种类、干燥制度和烧结温度等参数,结果表明:水固比主要影响煤矸石料浆粘度、发泡倍率和坯体干燥收缩率,胶凝剂主要影响煤矸石多孔坯体的机械强度,促凝剂主要影响胶凝时间,发泡剂种类主要影响煤矸石料浆的发泡性能,干燥制度主要影响坯体干燥质量,烧结温度决定了煤矸石多孔材料的线收缩率和抗压强度。最终确定主要的制备参数为:水固比为0.3、胶凝剂加入量为煤矸石粉用量的30 wt%、促凝剂加入量为胶凝剂的0.75 wt%、以十二烷基硫酸钠作发泡剂、采用干燥制度一对煤矸石多孔坯体进行干燥、最后在1000℃下烧结3 h。按此工艺参数可制备出0.6~1.2g/cm3的煤矸石多孔材料,其中0.80 g/cm3的煤矸石多孔材料,气孔结构大多为封闭孔、且气孔分布较为均匀、平均孔径大小约为100μm;线收缩率为6.89%,抗压强度为3.85 MPa;在环境平均温度为150℃时煤矸石多孔材料的导热系数约为0.144W/(m·k),800℃时其导热系数为0.240 W/(m·k)。
[Abstract]:Coal gangue is one of the largest industrial solid wastes in China, and its negative impact on the environment is becoming more and more serious. Most of the existing ways of using coal gangue in China show that the use of the added value is low and the utilization rate is low. The use of high efficiency and environmental protection method to prepare the inorganic energy material is to increase the added value and utilization of the gangue. In this paper, the coal gangue of Zhou Yuan Shan Coal Mine of Zixing Mining Bureau is used as the raw material and the silica sol is used as the gelatin agent to prepare the lightweight porous material of coal gangue with a density of 0.6~1.2 g/cm3 through the foam gel method. First, after the analysis of the chemical composition of the gangue of Zhou Yuan Shan, the coal gangue mainly contains SiO2 and Al2O3, sulfur content is contained. The quantity is only 0.11%, and the mineral composition analysis shows that the coal gangue mainly contains quartz and kaolinite, which belongs to the clay gangue, and the ball milling and screening of the gangue shows that the size of the sieve particles gradually decreases with the prolongation of the ball milling time, and the average size of the coal gangue powder with an average diameter of 77.65 mu m after the ball milling after the 28 mesh sieve is obtained. The coal gangue porous material is prepared by using this powder as raw material. Secondly, the water solid ratio of coal gangue slurry, the amount of gelling agent, the amount of coagulant, the kinds of foaming agent, the drying system and the sintering temperature have been studied. The results show that the water to solid ratio mainly affects the viscosity of the coal gangue slurry, the foaming rate and the drying shrinkage of the body, and the main gelling agent. In order to influence the mechanical strength of the gangue porous body, the coagulant mainly affects the gelation time, the type of foaming agent mainly affects the foaming performance of the coal gangue slurry. The drying system mainly affects the drying quality of the body, and the sintering temperature determines the line shrinkage and the compressive strength of the coal gangue porous material. With the ratio of 0.3, the dosage of gelling agent is 30 wt% of the coal gangue powder, the dosage of the coagulant is 0.75 wt% of the gelling agent, and the twelve alkyl sodium sulfate is used as the foaming agent. The drying system is used to dry the coal gangue porous body. Finally, the 0.6~1.2g/cm3 coal gangue porous material can be prepared by sintering 3 h. under 1000 centigrade, 0 of which are 0. The pore structure of coal gangue in.80 g/cm3 is mostly closed hole, and the distribution of pore is more uniform, the average pore size is about 100 mu m, the line shrinkage is 6.89%, the compressive strength is 3.85 MPa, and the thermal conductivity of the coal gangue porous material is about 0.144W/ (M. K) at the average temperature of 150 C, and the thermal conductivity is 0.240 W/ (m k) at 800 degrees C.
【学位授予单位】：湖南科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD849.5;TB383.4

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