减水剂对全尾砂胶结膏体充填材料性能的影响研究

发布时间：2018-02-04 12:09

本文关键词： 全尾砂胶结膏体充填材料减水剂粉料浆体的分散度流动度无侧限抗压强度　出处：《郑州大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着我国国民经济持续、高速增长，采矿工业得到快速的发展。但是采矿工业在为国民经济建设提供原材料的同时也产生了大量废弃物—尾砂。大量尾砂堆放于地表会破坏土地，污染环境，并且井下存在大量采空区，给自然生态与社会经济生活带来负面影响，这已成为目前亟待解决的重大问题。对于尾砂的处理，最重要的手段是将其制成全尾砂胶结膏体充填材料并充填到地下采空区，这既解决了全尾砂堆积在地表的环境污染问题，又保证了采空区不塌陷的生态平衡问题。通过检索相关文献，了解全尾砂膏体料浆研究现状和存在的问题，针对这些的问题，本文主要进行了如下工作：（1）对本论文中所用到的原材料的物理化学性能进行分析和测试，，了解所用到的试验方法的原理并掌握操作过程。（2）全尾砂胶结膏体料浆流动性测试方法的研究目前国内测量全尾砂胶结膏体充填材料（Cemented Paste Backfill，CPB）流动性的方法是参考混凝土流动度的测量方法—坍落度法进行测量。另外利用流变仪可以测量材料的流变特性，了解材料在输送时的参数。本文通过试验分析和研究了上述两种方法测量CPB的原理及优缺点，并提出了利用电动跳桌测量CPB流动度，分析了电动跳桌法测量CPB流动性的原理、可行性及精确性，并在后续试验中使用电动跳桌法进行CPB流动性的测量。（3）研究减水剂对CPB中粉体材料的分散作用。选择水泥混凝土领域常用的5类减水剂（聚羧酸系高效减水剂、萘系高效减水剂、氨基高效减水剂、脂肪族高效减水剂和木质素磺酸盐类减水剂）和CPB中常用的5种粉料（水泥、粉煤灰、矿渣粉、细尾砂粉和石灰石粉）进行了减水剂对粉料分散性的对比试验研究。试验证明聚羧酸系高效减水剂对水泥、矿渣粉和粉煤灰的分散效果最好，脂肪族高效减水剂对石灰石粉和尾砂粉的分散效果最好，对粉煤灰的分散效果也较好（仅次于聚羧酸系高效减水剂）。由于全尾砂CPB中尾砂粉和粉煤灰和/或石灰石粉的含量远大于水泥和矿渣粉，并且脂肪族高效减水剂的单价约为聚羧酸系高效减水剂单价的1/4，所以脂肪族高效减水剂将是制备全尾砂胶结膏体充填材料性价比最高的减水剂。（4）减水剂对CPB性能的影响及机理探讨本文共制备了18组试件，固定料浆的流动度（即坍落度为180mm），采用掺减水剂和未掺减水剂的料浆及其固化体作对比研究，其中水泥掺量为3%、5%和7%，养护龄期为7d、14d和28d。试验证明在保持料浆坍落度相同的条件下，掺减水剂比未掺减水剂的料浆浓度可提高四个百分点。结合压汞测孔法得到的结果和抗压强度试验结果，说明减水剂可以打开浆体中絮凝结构，细化固化体孔径，从而提高固化体的各龄期（7d、14d和28d）抗压强度。
[Abstract]:Along with our country national economy continues, the high speed growth. Mining industry has been rapidly developed. But mining industry provides raw materials for national economic construction, but also produces a large number of waste-tailings. A large number of tailings stacked on the surface will damage the land and pollute the environment. And the existence of a large number of goaf underground has brought negative impact to natural ecology and social economic life, which has become an important problem to be solved. For the treatment of tailings, the most important means is to make them into full tailing cemented paste filling materials and fill them into underground goaf, which not only solves the problem of environmental pollution caused by the accumulation of total tailings on the surface. The ecological balance of goaf is guaranteed. Through searching the relevant literature to understand the research status and existing problems of paste slurry of whole tailings, the main work of this paper is as follows: 1) analyzing and testing the physical and chemical properties of the raw materials used in this paper, understanding the principle of the test methods used and mastering the operation process. Study on the testing method of the fluidity of the whole tailings cemented paste slurry At present, the whole tailings cemented paste filling material, Cemented Paste Backfill, is measured in China. The fluidity of CPB is measured by the slump method, which is the measuring method of the fluidity of concrete. In addition, the rheometer can be used to measure the rheological characteristics of the material. In this paper, the principle, advantages and disadvantages of the two methods for measuring CPB are analyzed and studied, and the measurement of CPB fluidity by electric hopping table is proposed. The principle, feasibility and accuracy of CPB fluidity measurement by electric table hopping method are analyzed, and the measurement of CPB fluidity is carried out by using electric hopping table method in subsequent tests. The dispersion of superplasticizer to powder material in CPB was studied. Five kinds of water-reducing agents (polycarboxylic acid superplasticizer, naphthalene superplasticizer and amino superplasticizer) are selected in the field of cement concrete. Aliphatic superplasticizer and lignosulfonate superplasticizer) and 5 kinds of powder (cement, fly ash, slag powder commonly used in CPB). The dispersity of superplasticizer to powder was studied by contrast test. It was proved that polycarboxylic acid superplasticizer had the best dispersing effect on cement, slag powder and fly ash. Aliphatic superplasticizer has the best dispersion effect on limestone powder and tailings powder. The dispersion effect of fly ash is better than that of polycarboxylic acid series superplasticizer. Because the content of tailing powder, fly ash and / or limestone powder in CPB is much higher than that in cement and slag powder. And the unit valence of aliphatic superplasticizer is about 1 / 4 of that of polycarboxylic acid superplasticizer, so aliphatic superplasticizer will be the best water reducer to prepare the whole tailings cemented paste filling material. The effect of Water reducing Agent on the Properties of CPB and its Mechanism In this paper, 18 groups of specimens were prepared, the fluidity of fixed slurry (i.e. slump was 180mm), the slurry and its solidification with and without water reducer were compared, and the cement content was 3%. The curing period is 7d ~ 14d and 28d. It is proved that under the condition of keeping the same slump of slurry, the curing age is 7d ~ 14d and 28d. The mixture of water reducing agent can increase the slurry concentration by 4 percentage points compared with that without water reducing agent. Combined with the results of mercury injection and compressive strength test, it shows that the water reducing agent can open the flocculation structure in the slurry. The pore size of the solidified body was refined to increase the compressive strength of the solidified body for 14 d and 28 d.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TD926.4

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