【作者】 胡家国；

【导师】 古德生；

【作者基本信息】 中南大学 ， 采矿工程， 2004， 博士

【摘要】 作为金属矿山地下开采使用最有效、最广泛的方法之一的充填采矿法,因要消耗大量水泥作为采空区的充填胶凝材料,造成采矿成本太高,成为地下矿山使用该采矿方法的重大技术难题之一。而我国火力发电厂每年排放的工业固体废料——粉煤灰上亿吨,堆放在地表,严重污染环境。因此开展粉煤灰的综合利用研究对环境保护、资源的综合回收利用具有重要的战略意义。本文针对粉煤灰因含有潜在胶凝活性,可以开发成为一种来源广、价格低廉的充填胶凝材料的特点,进行了较为全面、系统的研究: （1） 综合利用有机化学、胶体化学、热力学、物相分析等基础理论,从粉煤灰的物理性质、化学成分,活化机理、充填料浆体结构的形成过程,探讨了粉煤灰、水泥、尾砂胶结充填料浆的水化反应机理及用于矿山胶结充填时作为胶凝剂的可能性; （2） 借助于X衍射分析仪及扫描电镜SEM对充填料和充填体的组成成分及微观结构进行了观测分析,揭示了充填体的微观形态:它是由尾砂,水化生成物、未水化的粉煤灰颗粒、水及少量的空气构成,是一个固-液-气的三相多孔体系; （3） 粉煤灰的活性可以通过外加剂来激发,3%石灰、2%石膏和0.5%CaCl₂的加入可以明显地提高粉煤灰的水化活性,从而提高充填体的强度; （4） 根据粉煤灰、水泥、尾砂系统的反应过程特点,建立了粉煤灰、水泥水化反应的物理模型,依据水化反应物理模型,采用TG、DT、SEM、EDT、XRD等化学分析以及宏观抗压强度等方法,结合硅酸盐水泥和石灰的有关水化反应理论,揭示了水泥、粉煤灰、尾砂体系是一个分阶段、多层次的水化反应过程; （5） 以Ca（OH）₂作为胶结充填砂浆中粉煤灰火山灰反应和水泥熟料水化反应的桥梁建立的水化反应动力学模型,基本上与浆体实际水化反应过程相符;从水化反应动力学模型来看,提高粉煤灰水化反应程度和浆体浓度是提高硬化体强度的关键所在,特别是砂浆浓度从65%提高到70%时,系统的水化反应度提高了25%左右,而粉煤灰的则提高了55%以上;而浓度提高到75%时,则系统水化反应度提高了58%以上,粉煤灰的提高了1.5倍以上; （6） 激发剂作用下的粉煤灰火山灰反应是阶段性的吸收反应,激发剂的作用是通过离子独立进行的,OH^-和Na⁺能增强四面体网络的解体能力,而Ca²⁺和SO₄^2-则促进水化产物的形成;粉煤灰对Ca（OH）₂的吸收是非平衡吸收,原因一方面在于粉煤灰中的Ca²⁺溶出,另一方面也与水化产物的转变和水化产物中Ca²⁺、OH^-更多还原

【Abstract】 As one of the best effective and broadest mining method used by metal mine, for using up much cement as the cementing materials and makes the mining cost high, the filling mining used in underground mine becomes the fatal technology problem. The solid castoff — fly ash discharged by fire power plants in our country has over a hundred million tons, it piles up on ground and pollutes environment. So, developing all-round use fly ash has important strategic means to environmental protect and resource compositive applications. The dissertation has studied fly ash roundly and systemically aiming at its potential cementing performance and it can be developed a broader coming and cheaper filling cementing material.（1） Compositive using basic theories knowledge, such as sonochemistry, colloidal chemistry, thermodynamics, phase analysis, the paper has studied the filling material hydrating reaction mechanism on fly ash ,cement and tailings and the probability used as cementing agent in mine cementing filling from fly ash’s physical performance, chemical component, activating mechanism and the forming process of filling materials frame.（2） Recuring XRD and SEM to observe and analysis filling materials and composing component and microcosmic frame of filling body, the paper opens out the filling body’s microcosmic configuration: it is a three-phase and a great deal of holes system forming from tailings, non-hydrating fly ash, water and a little of air.（3） The fly ash’s activeness can be activated by activators. Joining lime, gypsum and CaCl₂ may increase fly ash’s activeness clearly and improve filling body’s intensity.（4） According to the characteristic fly ash , cement and tailings system hydrating process, the paper builds up a physical model of fly ash , cement and tailings hydrating reaction. Thereundering the model and using TG, DT, SEM, EDT, XRD et al and filling body’s intensity, combining the hydrating theories of cement and lime, the paper open out the hydrating system of fly ash, cement and tailings is a grading, multilayer process.（5） Using Ca（OH）2 as the bridge the fly ash and cement reaction in filling slurry to build the model of hydration reaction kinetics matchs case the true reaction. From the model, to increase the reaction degree of fly ash and the thickness of filling slurry are the key to improve the intensity of filling body. Especially, when the thickness of filling slurry rises from 65% to 70%, the reaction degree in system rise 25%, and the fly ash 55%; when thickness rise to 75%, the reaction degree rise 58% and the fly ash 1.5 times.（6） Under the function of activators, the hydrating reaction performance of fly ash is an absorbing by stage. Activators work by ions independently, OH" and Na+ can enhance the network tetrahedron broken ability of vitreous body in fly ash, and Ca2+ and SO42" promote the forming of hydrating products. The absorption of Ca（OH）2 by fly ash is imbalance. One of the reasons is the dissolving out of Ca2+, and the other is the transition of hydrating products and the difference in Ca2+ and OH" content in hydrating products.（7） The paper educe the conclusions: the fly ash in mine filling can not only advance the filling body’s intensity, improve the filling body’s frame, but also decrease the sieve rate in filling body, reduce the draining cost under well, lessen the filling pollution to under well environment.（8） The industry test make know: the fly ash filling body is more advantageous to its intensity advance in the moist environment in well, and can save a great deal of dosage of cement to reduce the filling cost.This study lays the foundation of the farther use of artificial pozzolana including fly ash, smelt slag et al, and break a new path for the fly ash’s compositive utilization. So, the study has prominent economical and social benefit.更多还原