【作者】 任亚峰；

【导师】 冯国瑞；

【作者基本信息】 太原理工大学 ， 矿产普查与勘探， 2012， 硕士

【摘要】 采空区充填是目前解决煤矿开采沉陷及地表破坏最为有效的方法,也是防治煤矿开采诱发地质灾害的重要技术措施,该技术还可从源头治理煤矸石、粉煤灰无序堆积造成的环境污染,实现固体废物资源化,改变先污染后治理的现状,促进勘探—采煤—矿山环境治理全过程控制技术的发展。充填材料是充填采空区技术的核心,其中胶结充填材料的性能决定充填效果,影响充填成本的高低,对最终的地表减沉效果起着关键作用。为此,本论文通过矿物成分测试、浆体流动性试验、试件强度试验和理论分析等,对矸石-粉煤灰充填料的配料性能及配比进行了研究,取得了一定的创新成果。根据充填采空区的工艺流程及采空区岩层变形理论,对充填材料的基本性能要求进行了分析。充填体的早期强度需达到0.15MPa才能满足其稳定自立的能力；充填体的后期强度应与充填体在采空区所受的载荷相匹配。为达到泵送需求,充填材料的坍落度应达到20cm以上；泌水率应控制在1.5%-4.5%,以保证充填材料有一定的泌水能力,又不过度泌水；粗骨料煤矸石颗粒应达到一定的级配要求。对塔山矿区煤矸石的化学成分、颗粒特征及矿物组成进行了详细分析,其煤矸石颗粒属粘土质矸石,性质较为稳定,适宜用于充填配料的粗骨料；其原状煤矸石颗粒中,大颗粒比重过大,配比时需加以破碎。塔山电厂粉煤灰的化学成分及矿物组成分析表明,该电厂粉煤灰具有一定的火山灰活性,可用于充填配料,但钙含量较低、活性欠佳,充填配料时要加钙并适当的激发其活性。论文还分析研究了充填配料中涉及到的粉煤灰、水泥、辅助材料及外加剂的性能和作用机理。采用石灰吸收法,对塔山电厂粉煤灰进行了化学激发实验,结果表明,碱性激发剂、硫酸盐激发剂和氯盐激发剂均对粉煤灰有激发效果,配比时优先考虑应用Ca(OH)2、CaSO4和CaCl2。实验分析了充填配料的流动能力,结果表明浆体坍落度随粉煤灰掺量的增加呈上升趋势,但掺入量也不能太多,否则会影响材料坍落度,泌水率对粉煤灰掺入量也有一定限制；坍落度随浆体质量浓度的增大而减小,泌水率随浆体质量浓度的增大而降低。为验证粉煤灰的激发效果,得到充填材料的最优配比,论文设计了粉煤灰、水泥和煤矸石配比试验和粉煤灰、石灰和石膏和煤矸石配比试验。粉煤灰、水泥和煤矸石配比试验表明,水泥是影响充填材料强度的最关键因素；浆体的浓度也对材料的强度有较大影响,特别对材料的后期强度影响明显；粉煤灰的增加对于充填材料的不同龄期强度影响有限。粉煤灰、石灰、石膏和煤矸石配比试验表明,各材料配比合理,不使用水泥也可满足充填材料的需求；石灰用量对试件强度的影响最大,只有石灰用量与粉煤灰相匹配时,才能最大发挥二者的水化作用,形成较大胶凝作用；石膏仅能起到改善材料强度的作用,对强度影响较小。更多还原

【Abstract】 Goaf filling is the current efficient solution of mining subsidence and surface damage and the important technical measures of prevention of geological disasters induced by mining. The technology can also control the environmental pollution caused by coal gangue and fly ash disordered stacking from the source. It could change solid waste into resources, change the treatment status after pollution, promoting the exploration, mining, mine environment management controlling technology development in whole process.The filling material is the core of filled goaf technology, wherein the backfill material performance determines the filling effect and affects the high or low cost of filling, which plays a key role in subsidence-reducing effect of the final surface. To this end, the mineral composition testing, the paste liquidity test, the specimen strength test and theoretical analysis are taken to study the performance and proportion of gangue-fly ash ingredients of the filling material. It has resulted in some innovations.According to the process of goaf-filling and the rock deformation theory in goaf areas, the basic performance of the filling material is analyzed. The early strength of the backfill should be above0.15MPa to meet their stable self-sustaining. The late strength of the backfill should match its load in goaf area. Bleeding rate should be controlled between1.5%～4.5%, in order to ensure that the filling material is capable of bleeding, without any excess. In order to achieve pumping demand, the slump of the filling material should be more than20cm. And the coal gangue of coarse aggregate should be met a certain gradation requirements.Coal gangue from Tashan Mine has been analyzed in chemical composition, particle characteristics and mineral composition in detail, and the result is that gangue particles are clayey gangue; its nature is more stable and suitable for coarse aggregate of the filling ingredients. Among the original coal gangue particles, the proportion of large particles is too large, so they need to be broken when mixing with other ingredients. An analysis about the chemical composition and mineral composition of the fly ash from Tashan power plant showed that the fly ash has pozzolanic activity and can be used in the filling ingredients, but the calcium and the activity content is low, and extra calcium should be added and the activity should be properly stimulated when the mixing the filling ingredients.It is also analyzed in this paper that the performance and mechanism of the filling ingredients involves the fly ash, cement, auxiliary materials and additives. The lime absorption method is adopted to take chemical excitation experiments on the fly ash in Tashan power plant, and the results show that the alkaline activator, sulfate activator and chloride activator can all stimulate the effect of fly ash. The priority in mixing the filling ingredients is an application of Ca(OH)2,CaSO4and CaCl2. The experiments analyzed the flow capacity of the filling ingredients, and the results are that paste slump tends to go upward with the increase of the fly ash, but the incorporation can not be too much, otherwise it will affect the slumps of the filling ingredients. The fly ash incorporation is limited by bleeding rate. Slump decreases as the paste concentration increases, and bleeding rate reduces as the paste concentration increases.In order to verity the stimulational results of fly ash and get the optimal proportion of filling material, the fly ash-cement and gangue proportioning test and the fly ash-lime-gypsum and gangue proportioning test were been designed. The fly ash-cement and gangue proportioning test indicates that cement is the key material influencing the strength of filling materials, the mass concentration also wields a large influence on the strength of filling materials, especially in later stages of the materials. The incorporation of fly ash’s influence is limited on concrete strength in different ages. The fly ash-lime-gypsum and gangue proportioning test indicates that if various materials are of reasonable proportion, the requirements of fill materials can be met without cement. Lime content most influences the specimen strength. When the content matches with fly ash, their hydration is best, and jellification is relatively better. Gypsum can only improve the strength, and the effect is not much.更多还原