高浓尾矿胶结充填材料的试验研究

发布时间：2018-06-15 04:35

本文选题：尾砂胶结充填材料 + 沉缩率　；参考：《西安建筑科技大学》2015年硕士论文

【摘要】：随着矿山的不断开采,排放出大量的尾矿,这不仅占用了大量的土地,而且污染了环境,同时矿山形成采空区,如果不及时充填采空区,可能造成采空区塌陷,给采矿和地面建筑物带来安全隐患,高浓尾矿胶结充填材料的研发为解决上述问题提供了一种途径。本文采用全尾砂为集料,首先研究了含水泥尾矿胶结充填材料的配合比及性能,灰砂比为1:1 0、固体浓度为7 8%,采用正交试验进行了极差和方差分析,研究了石膏总质量分数、半水石膏与二水石膏的比例、生石灰的掺量对全尾砂胶结充填材料的流动性能、沉缩率和力学性能的影响,得出了最佳的试验配合比;然后,研究了无水泥尾矿胶结充填材料的配合比及性能,采用单因素试验研究灰砂比、固体浓度、粉煤灰掺量对全尾砂胶结充填材料流动性能、沉缩率和力学性能的影响;在此基础上,研究了二水石膏、半水石膏、石灰对全尾砂胶结充填材料沉缩率和力学性能的影响,得出了最佳的配合比。主要结论如下:(1)影响含水泥全尾砂胶结充填材料1h坍落度损失的主要因素为石灰掺量和半水石膏与二水石膏的比例;影响充填体沉缩率的主要因素为半水石膏与二水石膏的比例,其次是石膏总掺量;影响3d、7d和2 8d的抗压强度主要因素为半水石膏与二水石膏的比例,随着充填体龄期的增长,影响作用逐渐减弱。(2)含水泥全尾砂胶结充填材料胶凝材料的最佳配比为矿渣6 0%,水泥1 5%,半水石膏1 0%,二水石膏1 0%,石灰5%。料浆1 h后坍落度仍可满足泵送要求,充填体3 d抗压强度为0.99 MPa,2 8d抗压强度为4.6 8MPa,充填体沉缩率为3.5%,满足强度和充填接顶的要求。(3)无水泥全尾砂胶结充填材料中,随着固体浓度的增加,充填体的沉缩率逐渐减小,最佳充填的固体浓度为7 8%;粉煤灰的增加有利于料浆坍落度的增大,粉煤灰掺量的减少使充填体沉缩率降低;灰砂比的增加有助于料浆流动性的提高。(4)在无水泥全尾砂胶结充填材料中,二水脱硫石膏掺量的增加有助于充填体沉缩率的降低和充填体早期强度的增长;磷石膏掺量的增加有助于后期强度的提高而降低了早期强度;半水石膏掺量的增加有助于充填体沉缩率的降低,合适的掺量利于充填体早期强度的提高;少量石灰有利于充填体早后期强度的提高。
[Abstract]:With the continuous mining of mines, a large amount of tailings are discharged, which not only occupies a lot of land, but also pollutes the environment. At the same time, goaf is formed in the mine. If the goaf is not filled in time, the goaf may collapse. The research and development of cemented filling materials of high concentration tailings provide a way to solve the above problems. In this paper, the mixture ratio and performance of cemented filling material containing cement tailings are studied in this paper. The ratio of cement to sand is 1:1 and the solid concentration is 7.8. The orthogonal test is used to carry out the range difference and variance analysis, and the total mass fraction of gypsum is studied. The effects of the ratio of hemihydrate gypsum to dihydrate gypsum, the content of quicklime on the fluidity, shrinkage rate and mechanical properties of the cemented filling material are obtained. The mixture ratio and performance of cemented filling materials without cement were studied. The effects of the ratio of cement to sand, solid concentration and fly ash content on the fluidity, shrinkage rate and mechanical properties of cemented filling materials were studied by single factor test. On this basis, the effects of gypsum dihydrate, gypsum hemihydrate and lime on the sinking rate and mechanical properties of cemented filling materials were studied, and the optimum mix ratio was obtained. The main conclusions are as follows: (1) the main factors affecting the slump loss of cemented filling materials are lime content and the ratio of hemihydrate gypsum to gypsum dihydrate; The main factors influencing the shrinkage rate of filling body are the ratio of hemihydrate gypsum to dihydrate gypsum, followed by the total amount of gypsum, and the main factor of influencing the compressive strength of 3 d and 28 d is the ratio of hemihydrate gypsum to dihydrate gypsum, which increases with the age of filling body. The best ratio of cementing material for cemented filling material containing cement is slag 60, cement 1.5, hemihydrate gypsum 10, gypsum dihydrate 10, lime 5. The slump of the slurry can still meet the pumping requirement after 1 hour. The compressive strength of the filling body in 3 days is 0.99 MPA / 2, the compressive strength of the filling body is 4.68 MPA / d, and the sinking rate of the filling body is 3.5MPa, which satisfies the requirements of strength and filling top. With the increase of solid concentration, the sinking rate of the filling body gradually decreases, the optimum solid concentration is 7.8%, the increase of fly ash is beneficial to the increase of slump of slurry, and the decrease of fly ash content decreases the sinking rate of filling body. The increase of lime-sand ratio contributes to the improvement of slurry fluidity. (4) in cemented filling materials without cement, the increase of gypsum content in desulphurization of dihydrate contributes to the decrease of sinking rate and the increase of early strength of filling body. The increase of phosphogypsum content contributes to the increase of later strength and decreases the early strength, the increase of hemihydrate gypsum content contributes to the decrease of sinking rate of the filling body, and the appropriate amount of addition is conducive to the increase of the early strength of the filling body. A small amount of lime is propitious to increase the strength of the filling body in the early and late stage.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD926.4

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