红黏土比表面积试验研究

发布时间：2018-01-27 07:30

本文关键词： 红黏土比表面积甘油法亚甲基蓝法乙二醇乙醚法矿物组成　出处：《桂林理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：比表面积(Specific Surface Area)是黏性土重要的物理化学指标,本文通过对比各种不同比表面积测试技术的特点后,选取了合适的测试技术,以广西柳州的红黏土为研究对象,分析了柳州红黏土的比表面积特点及影响因素,主要研究结果如下:(1)采用亚甲基蓝(Methylene Blue)吸附法、乙二醇乙醚(Ethylene Glycol Monoethyl Ether)吸附法、甘油(Glycerin)吸附法以及风干含水率经验公式对五种黏土的SSA进行试验测定及估算,试验结果表明:对于不含蒙脱石的土样,各种方法测试结果较为一致,偏差较小;但对于含蒙脱石的土样,EGME法试验值比其他方法偏小;亚甲基蓝法具有与实际工作状态接近的优点,快速简便,是一种较为适合的方法。(2)柳州红黏土的主要矿物为高岭石、伊利石、石英、针铁矿,可溶性阳离子主要为Na+、Ca2+、Mg2+,其比表面积大小范围在48.93~61.17 m2/g之间。位于表层2-3m范围内的土体石英含量高、高岭石和伊利石黏土矿物含量低,可溶性离子中含量Ca2+、Mg2+也相对较低,因此其比表面积最小。由于MB法是在饱和状态下试验,因此采用MB法测定的柳州红黏土比表面积比用BET吸附法要大。(3)分别配置浓度为1.5%、3.0%和4.5%的盐酸溶液对柳州红黏土进行为时2d、7d、14d的浸泡试验,发现经盐酸溶液浸泡的柳州红黏土,随着酸浓度提高,浸泡时间延长,红黏土的比表面积逐渐变小,呈现先快后慢的变化趋势,不同浓度水平的红黏土经过2d的浸泡后比表面积降低可达30%。比表面积的降低与酸对游离氧化铁的溶解有关,游离氧化铁本身的比表面积丧失超过了土中黏粒含量增加引起的比表面积增加,导致土中比表面积整体呈现减小的趋势。
[Abstract]:Specific Surface area) is an important physical and chemical index of clay soil. Taking the red clay in Liuzhou of Guangxi as the research object, the characteristics of specific surface area and the influencing factors of the red clay in Liuzhou were analyzed. The main results are as follows: 1) methylene blue method is used. Ethylene Glycol Monoethyl ether adsorption method. The SSA of five kinds of clay was measured and estimated by glycerol Glycerin adsorption method and the empirical formula of air-dried moisture content. The results showed that: for soil samples without montmorillonite. The results of various methods are consistent and the deviation is small. However, the test value of EGME method for soil samples containing montmorillonite is smaller than that of other methods. The methylene blue method has the advantage of being close to the actual working state and is a more suitable method. It is a more suitable method. The main minerals of Liuzhou red clay are kaolinite, Illite, quartz and goethite. The main soluble cations were Ca 2 + mg 2. The specific surface area is between 48.93 and 61.17 m2 / g. The quartz content of soil is high and the clay content of kaolinite and Illite is low in the range of 2-3m in surface layer. The content of Ca2 ~ (2 +) mg _ (2) in soluble ions is also relatively low, so its specific surface area is the smallest. Therefore, the specific surface area of Liuzhou red clay determined by MB method is larger than that by BET adsorption method. 3.0% and 4.5% hydrochloric acid solution soaked Liuzhou red clay for 2 days and 7 days for 14 days. It was found that the immersion time of Liuzhou red clay soaked in hydrochloric acid solution was prolonged with the increase of acid concentration. The specific surface area of red clay gradually becomes smaller, showing the change trend of first fast and then slow. The specific surface area of red clay with different concentrations decreased by 30% after immersion for 2 days. The decrease of specific surface area was related to the dissolution of free iron oxide by acid. The loss of the specific surface area of free iron oxide itself is more than the increase of the specific surface area caused by the increase of clay content in the soil, which leads to the overall decrease of the specific surface area of the soil.
【学位授予单位】：桂林理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU446

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