煤矸石—矿渣—粉煤灰地质聚合物复合活化研究
发布时间：2019-03-11 07:25
【摘要】：地质聚合物作为一种新型绿色胶凝材料,由于其具有强度高、硬化快、耐酸碱腐蚀、耐高温等诸多特性,且多种富含活性硅铝成分的固体废弃物,如矿渣、粉煤灰和煤矸石等均可作为地质聚合物的主要原料,实现“灰色”水泥向“绿色”的转变,因此备受关注,已经成为研究热点。本文是国家自然科学基金煤炭联合项目《煤矸石在水泥和混凝土资源化利用中关键科学问题研究》(U1261122)的子项目,所有研究成果都是在该基金的资助下完成并取得的。本文首先采用热活化和机械活化的方法,激发煤矸石潜在的活性。接下来以活化煤矸石、矿渣和粉煤灰为主体材料,在碱硅酸盐作用下(化学活化),制备煤矸石-矿渣-粉煤灰地质聚合物,重点研究煤矸石的复合活化技术。第一步选择激发剂的陈化时间、氢氧化钾掺量和激发剂品种三个因素,按正交表L16(45)进行试验研究,以胶砂抗折和抗压强度为目标函数,确定地质聚合物配体的最佳配合比；第二步对煤矸石进行热、机械和化学活化,分别选择煅烧温度、研磨时间和激发剂掺量作为影响因素,通过单因素对比试验,确定各因素的最佳取值区间；第三步利用二次响应曲面中的中心组合设计进行试验研究,建立煤矸石-矿渣-粉煤灰地质聚合物中煤矸石活化方式对应参数与其活性对应蚕食之间的定量关系。取得以下研究成果：(1)煤矸石-矿渣-粉煤灰地质聚合物激发剂配体的最优方案为：激发剂品种为硅酸钠和氢氧化钾,激发剂陈化时间48h,氢氧化钾所占激发剂的比例为20%。各因素对胶砂强度影响程度大小顺序为：激发剂种类激发剂陈化时间氢氧化钾所占激发剂的比例。(2)阜新清河门矿煤矸石：①当煅烧温度控制在650℃～750°时,其配制的煤矸石-矿渣-粉煤灰地质聚合物胶砂强度最高,说明煤矸石的活性最佳。XRD和SEM分析表明,随温度升高煤矸石中的高岭石、云母等发生脱水反应,700℃煅烧的煤矸石Si离子和Al离子溶出量最大。矿渣使聚合浆体整体结构更为致密,粉煤灰和煅烧煤矸石中含有大量的铝,形成具有架状结构的水合铝硅酸盐。②最优的粉磨时间区域为1min-3min。灰色关联分析显示,粒径小于11.11μm的煤矸石颗粒与胶砂3d和28 d抗折、抗压强度呈现正相关,粒径大于11.11 gm的煤矸石颗粒与胶砂3d和28 d抗折、抗压强度呈现负相关。③当激发剂配体的掺量为20%-22.5%时,可以配制出满足62.5R强度等级的煤矸石-矿渣-粉煤灰地质聚合物。(3)建立了煤矸石煅烧温度、研磨时间和配体掺量三个因素与胶砂强度之间的回归方程,且回归方程拟合程度良好。
[Abstract]:As a new green cementitious material, geopolymer has many characteristics, such as high strength, fast hardening, acid-alkali corrosion resistance, high temperature resistance, and many kinds of solid wastes rich in active silicon and aluminum, such as slag, Fly ash and coal gangue can be used as the main raw materials of geopolymer to realize the transformation from "grey" cement to "green", so it has been paid more and more attention and has become a research hotspot. This paper is a sub-project of the joint project of National Natural Science Foundation of China "Research on key Scientific problems of Coal gangue in the Utilization of cement and concrete" (U1261122). All the research results are completed and obtained with the aid of this fund. In this paper, thermal activation and mechanical activation are used to stimulate the potential activity of coal gangue. Next, coal gangue-slag-fly ash geopolymer was prepared by using activated coal gangue, slag and fly ash as the main materials, under the action of alkali silicate (chemical activation), and the composite activation technology of coal gangue was mainly studied. In the first step, the aging time of the activator, the amount of potassium hydroxide and the variety of the activator were selected and tested according to the orthogonal table L16 (45). The flexural strength and compressive strength of the rubber sand were taken as the objective functions. The optimum composition ratio of geopolymer ligands was determined. In the second step, the thermal, mechanical and chemical activation of coal gangue was carried out. The calcination temperature, grinding time and the amount of activators were selected as the influencing factors, and the optimum range of each factor was determined by single factor contrast test. In the third step, a quantitative relationship between the corresponding parameters of coal gangue activation mode and the corresponding activity of coal gangue in coal gangue-slag-fly ash geopolymer is established by using the central combination design in the quadratic response surface. The research results are as follows: (1) the optimum scheme of the activator ligand of coal gangue-slag-fly ash geopolymer is: sodium silicate and potassium hydroxide, the aging time of the activator is 48h. Potassium hydroxide accounts for 20% of activators. The order of the influence of various factors on the strength of gelled sand is as follows: the proportion of potassium hydroxide in the aging time of activators. (2) Coal gangue in Qinghemen Mine, Fuxin: 1when the calcination temperature is controlled at 650 鈩，
本文编号：2438075
[Abstract]:As a new green cementitious material, geopolymer has many characteristics, such as high strength, fast hardening, acid-alkali corrosion resistance, high temperature resistance, and many kinds of solid wastes rich in active silicon and aluminum, such as slag, Fly ash and coal gangue can be used as the main raw materials of geopolymer to realize the transformation from "grey" cement to "green", so it has been paid more and more attention and has become a research hotspot. This paper is a sub-project of the joint project of National Natural Science Foundation of China "Research on key Scientific problems of Coal gangue in the Utilization of cement and concrete" (U1261122). All the research results are completed and obtained with the aid of this fund. In this paper, thermal activation and mechanical activation are used to stimulate the potential activity of coal gangue. Next, coal gangue-slag-fly ash geopolymer was prepared by using activated coal gangue, slag and fly ash as the main materials, under the action of alkali silicate (chemical activation), and the composite activation technology of coal gangue was mainly studied. In the first step, the aging time of the activator, the amount of potassium hydroxide and the variety of the activator were selected and tested according to the orthogonal table L16 (45). The flexural strength and compressive strength of the rubber sand were taken as the objective functions. The optimum composition ratio of geopolymer ligands was determined. In the second step, the thermal, mechanical and chemical activation of coal gangue was carried out. The calcination temperature, grinding time and the amount of activators were selected as the influencing factors, and the optimum range of each factor was determined by single factor contrast test. In the third step, a quantitative relationship between the corresponding parameters of coal gangue activation mode and the corresponding activity of coal gangue in coal gangue-slag-fly ash geopolymer is established by using the central combination design in the quadratic response surface. The research results are as follows: (1) the optimum scheme of the activator ligand of coal gangue-slag-fly ash geopolymer is: sodium silicate and potassium hydroxide, the aging time of the activator is 48h. Potassium hydroxide accounts for 20% of activators. The order of the influence of various factors on the strength of gelled sand is as follows: the proportion of potassium hydroxide in the aging time of activators. (2) Coal gangue in Qinghemen Mine, Fuxin: 1when the calcination temperature is controlled at 650 鈩，
本文编号：2438075
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