【作者】 周华强；

【导师】 冯启言； 赵恒；

【作者基本信息】 中国矿业大学 ， 环境工程（专业学位）， 2024， 硕士

【摘要】 地质聚合物注浆材料与传统水泥相比具有原材料易获取、耐酸碱性强、成本低等优势,利用硅铝质矿山固废制备地质聚合物注浆材料不仅可以有效解决矿山固废大量堆积带来的环境和安全问题,还变废为宝为矿山环境安全治理提供了一种绿色新型高性价比注浆材料。本论文以粉煤灰和煤矸石这两种煤基固废作为地质聚合物的主要原料,以碱性固废电石渣作为干粉激发剂,制备新型地聚物注浆材料,研究该地聚物材料的性能和反应机理,通过原料混合球磨、腐化增强材料性能,系统研究了该地聚物材料的微观和宏观性能,揭示了其反应机理和主控因素,确定了最优配比,并对其环境友好性和适用性进行了评价,得出如下主要结论:(1)以电石渣作为干粉激发剂,制备了粉煤灰-煤矸石地聚物注浆材料,探讨了不同配比对性能的影响。流动度和28d抗压强度随着煤矸石掺量的增加而降低,结石率随煤矸石掺量的增加而提高;此外该注浆材料的性能还与电石渣添加量、液固比有着一定的关系,电石渣添加量与28d抗压强度、结石率呈正比,与流动度呈反比;液固比越高流动度越高、结石率越低,液固比为0.44时,该材料的28d抗压强度最高。(2)借助FTIR、XRD、SEM-EDS的微观分析手段,探讨了电石渣激发粉煤灰和煤矸石的地聚反应过程和机理。该材料聚合反应分为电石渣溶解、硅铝原料解聚、水化反应和聚合硬化四个过程。材料强度主要来源于水化反应产物钙矾石、C-A-S-H凝胶及C-S-H凝胶,粉煤灰掺量越多,原料活性越高,水化产物也随之增多,电石渣既提供了充足的OH~-,又弥补了原料含钙量较低的劣势。(3)利用机械混合球磨、腐化的方法改进制备工艺,可提高材料性能。机械混合球磨通过物理活化的方式改进了原料的粒径大小,增强原料活性,既促进水化反应的进行,也使结石体内部结构更紧密,较相同配比的材料流动度提高24%～203%,抗压强度提高3%～23%。腐化则是在球磨基础上将原料混合堆放28d,让其以固态的形态进行缓慢反应,流动度较未改进前提升15%～86%,抗压强度提升6%～109%。(4)基于响应曲面设计的方法,明确了不同因素对地聚物注浆材料性能参数的影响程度。对流动度的影响程度为:煤矸石掺量>液固比>电石渣添加量;对结石率的影响程度为:煤矸石掺量>液固比>电石渣添加量;对28d抗压强度的影响程度为:煤矸石掺量>电石渣添加量>液固比。(5)制备的注浆材料具有良好的环境友好性,有毒有害物质浸出率低,同时硬化后的结石体也不会对环境造成较大的碱污染。该材料在碱性环境中有较强的耐受性,甚至在碱性环境中力学性能得到进一步提升,但在酸性条件下容易发生酸蚀。该论文有图71幅,表19个,参考文献112篇。更多还原

【Abstract】 Geopolymer grouting materials have the advantages of easy access to raw materials,strong resistance to acids and alkalis,and low cost compared with traditional cement.The use of silica-aluminium mine waste to prepare geopolymer grouting materials can not only effectively solve the environmental and safety problems brought about by the massive landfill of mine waste,but also turn waste into treasure for the safe management of the mining environment to provide a new type of green and cost-effective grouting materials.In this thesis,two kinds of coal-based solid wastes,fly ash and coal gangue,were used as the main raw materials of geopolymer,and alkaline solid waste calcium carbide slag was used as a dry powder exciter to make new geopolymer grouting materials.We study the properties and reaction mechanism of the geopolymer material.Through the raw material mixing ball milling,decays to enhance the material properties.The microscopic and macroscopic properties of the geopolymer materials were systematically investigated,the reaction mechanism and main control factors were revealed,and the optimal ratio was determined.It was also evaluated for its environmental friendliness and applicability,and the following main conclusions were drawn:(1)Fly ash-gangue geopolymer grouting materials were made using calcium carbide slag as a dry powder exciter,and the effects of different ratios on the performance were explored.The fluidity and 28 d compressive strength decrease with the increase of gangue dosing,and the rate of stone formation increases with the increase of gangue dosing.In addition,the performance of the grouting material also has a certain relationship with the amount of calcium carbide slag additive,liquid-solid ratio.the liquid-solid ratio,the higher the amount of calcium carbide slag added to the higher rate of stone,the lower the fluidity.The higher the liquid-solid ratio the higher the fluidity and the lower the rate of stone,the liquid-solid ratio of0.44,the material’s 28 d compressive strength is the highest.(2)With the help of microscopic analysis means of FTIR,XRD,SEM-EDS,the geopolymerisation reaction process of calcium carbide slag stimulating fly ash and gangue was analysed to find the source of strength of the material,to understand the different chemical bonds under different components,the different crystalline p Hases and the different microscopic morp Hology,to jointly determine the reaction mechanism,and to classify it into four process.The material strength is mainly derived from the hydration reaction products calcite,C-A-S-H gel and C-S-H gel.The more fly ash the higher the activity of the raw material and the more hydration products.Calcium carbide slag provides both sufficient OH-and compensates for the disadvantage of lower calcium content of the raw material.(3)Improvement of the production process using mechanical mixing of ball milling and corrosion can improve material properties.Mechanical mixing ball milling improves the particle size of raw materials through p Hysical activation and enhances the activity of raw materials,which not only promotes the hydration reaction,but also makes the internal structure of materials more compact.With the same proportion of the material flow rate increased by 24% to 203%,compressive strength increased by 3% to 23%.Decay is the mixing and stacking of raw materials for 28 d on the basis of ball milling,allowing them to react slowly in a solid form.Improvement of fluidity by 15% to 86% and compressive strength by 6% to 109%over the unimproved period.(4)Based on the method of response surface design,the degree of influence of different factors on the performance parameters of ground polymer grouting materials is clarified.The degree of influence on the degree of fluidity is: Gangue mixing amount > liquid-solid ratio > calcium carbide slag addition amount;The degree of influence on the rate of stone formation is as follows: gangue mixing amount >liquid-solid ratio>calcium carbide slag addition amount;The degree of influence on28 d compressive strength is as follows: gangue mixing amount > calcium carbide slag addition amount > liquid-solid ratio.(5)The prepared grouting material has good environmental friendliness with low leaching rate of toxic and hazardous substances,while the hardened stone body does not cause large alkali pollution to the environment.The material is highly resistant to alkaline environments and even has further improved mechanical properties in alkaline environments,but is susceptible to acid corrosion under acidic solutions.更多还原