矿渣磷尾矿黏土混合物的力学性能研究

发布时间：2018-05-31 13:24

本文选题：磷尾矿 + 黏土混合物　；参考：《湖北工业大学》2017年硕士论文

【摘要】：论文以磷尾矿和黏土的混合物为研究对象,开展了系列试验,得到的研究成果及结论如下:(1)对磷尾矿进行击实试验,得出了磷尾矿最优含水率为30%,最大干密度为1.55g/cm3,其最优含水率比一般黏土要高,而最大干密度与黏土相比要低。对磷尾矿进行直剪试验可知磷尾矿的内摩擦角?为39.3°,黏聚力c为46.826kPa。由GZQ-1型全自动气压固结试验可知磷尾矿的压缩系数为0.41MPa-1,压缩模量为5.3MPa,按照土的压缩性分类,磷尾矿属于中压缩性土。(2)将掺量为5%,10%,15%,20%的磷尾矿掺入黏土中,进行比重试验,试验测得混合物的相对密度分别为2.728,2.716,2.706,2.688。而磷尾矿和黏土的比重分别为2.589,2.735。可知,随着磷尾矿掺量的增加,黏土混合物的相对密度随之减小,并且减小的趋势几乎呈线性。(3)在以上纯磷尾矿试验的基础之上还进行含水率为20%,干密度分别为1.55g/cm3和1.65 g/cm3,掺量为5%,10%,15%,20%的磷尾矿黏土混合物的直剪试验、压缩试验、三轴试验。在直剪试验中,黏聚力随着磷尾矿掺量的增加而呈非线性的增加,内摩擦角?随着磷尾矿掺量的增加而呈线性的减小。并且同一干密度条件下,干密度越大,内摩擦角?减小的趋势越大,随着磷尾矿含量的增加,黏土的抗剪强度得到增强。在压缩试验中。干密度为1.65 g/cm3掺量分别为5%、10%、15%、20%,所得到的压缩系数分别为:0.0051,0.0043,0.0036,0.0025;压缩指数分别为0.0031,0.0021,0.0015,0.002;压缩模量分别350 MPa,423 MPa,491MPa,702 MPa。黏土混合物的压缩系数随着磷尾矿掺量的增大而减小,压缩指数先增大后减小,当磷尾矿掺量为15%时,不同干密度磷尾矿的压缩指数同时达到最小值。在三轴试验中,不同干密度黏土混合物的主应力差值相差不大,干密度为1.65g/cm3的磷尾矿黏土的应力-应变关系曲线出现较为不明显的应变软化现象,干密度为1.55g/cm3时,仅在较低围压下出现应变软化现象。不同掺磷尾矿黏土的黏聚力c随着磷尾矿掺量的增加而增加,内摩擦角?随着磷尾矿掺量的增加而增加,当掺量为20%时,黏聚力c的增量最大。通过试验可知,磷尾矿掺入对黏土的力学性能具有较好的改良,为将其资源化利用提供了参考依据。
[Abstract]:Taking the mixture of phosphorus tailings and clay as the research object, a series of experiments have been carried out in this paper. The research results and conclusions are as follows: 1) compaction test of phosphorus tailings. The optimum moisture content of phosphorus tailings is 30% and the maximum dry density is 1.55 g / cm ~ 3. The optimum moisture content of phosphorus tailings is higher than that of common clay, but the maximum dry density is lower than that of clay. The direct shear test of phosphorus tailings shows the angle of internal friction of phosphorus tailings. The cohesion C is 46.826kPa. According to the fully automatic pressure consolidation test of GZQ-1 type, the compression coefficient of phosphorus tailings is 0.41MPa-1 and the compression modulus is 5.3MPa. according to the classification of compressibility of soil, phosphorus tailings belong to medium compressible soil. The experimental results show that the relative densities of the mixture are 2.728, 2.716, 2.706 and 2.688, respectively. The specific gravity of phosphorus tailings and clay is 2.589 and 2.735 respectively. It can be seen that the relative density of clay mixture decreases with the increase of the content of phosphorus tailings. And the decreasing trend is almost linear. (3) on the basis of the pure phosphorus tailings test above, the moisture content is 20, dry density is 1.55g/cm3 and 1.65 g / cm ~ 3, and the content is 5 ~ 1010 ~ 1515 ~ 20%, the direct shear test, compression test and triaxial test are carried out. In the direct shear test, the cohesive force increases nonlinearly with the increase of phosphorus tailings content, and the internal friction angle increases with the increase of the content of phosphorus tailings. The content of phosphorus tailings decreases linearly with the increase of the content of phosphorus tailings. And under the same dry density, the greater the angle of internal friction? The larger the decreasing trend, the stronger the shear strength of clay is with the increase of phosphorus tailings content. In the compression test. The dry density of 1. 65 g/cm3 is 5: 10, 10, 15 and 20, respectively, and the compression coefficient is 0. 0051, 0.0043, 0.0036, 0.0025, the compression index is 0. 0031, 0. 0021, 0. 0015, 0. 002, and the modulus of compression, respectively, is 350 MPA, 423 MPa, 491MPa / 702 MPa, respectively, and the compression index is 0. 0031, 0. 0021, 0. 0015, 0. 002, respectively. The compression coefficient of clay mixture decreases with the increase of the content of phosphorus tailings, and the compression index increases first and then decreases. When the content of phosphorus tailings is 15, the compression index of phosphorus tailings of different dry densities reaches the minimum at the same time. In triaxial test, the difference of principal stress of different dry density clay mixture is not different, and the stress-strain relationship curve of phosphorus tailings clay with dry density of 1.65g/cm3 is not obvious strain softening phenomenon, when dry density is 1.55g/cm3, Strain softening occurs only under lower confining pressure. The cohesive force c of different phosphorus-doped tailings clay increases with the increase of phosphorus tailing content, and the internal friction angle? With the increase of the content of phosphorus tailings, the increase of cohesion C is the largest when the content of phosphorus tailings is 20. The experiment shows that the addition of phosphorus tailings can improve the mechanical properties of clay, which provides a reference for the utilization of phosphorus tailings.
【学位授予单位】：湖北工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU41

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