高浓度高流动性煤矸石胶结充填材料试验研究

Experimental study on coal gangue cemented filling material of high concentration and high fluidity

煤矸石胶结充填材料的高浓度高流动性往往不能很好的兼顾。为解决现有充填开采技术中充填材料要么用水量过高(浓度过低)导致井下脱水后影响作业环境,要么浓度过高,流动性和管输性能不好导致堵泵和堵管等问题。通过在胶结充填材料中掺加一定量的水泥、煤矸石粉料(≤0.075 mm)和高效减水剂,利用正交试验和极差分析的方法,研究分析了不同配比的充填材料的流动性和强度性能。综合利用扫描电镜SEM、EDS能谱分析、X荧光光谱分析(XRF)、X射线衍射分析(XRD)和傅里叶变换红外光谱(FTIR) 5种微观分析手段,对煤矸石的微观形貌、元素组成、氧化物含量和矿物组成进行了分析,并对煤矸石的组成和微观结构对宏观性能的影响进行了探究。揭示了决定充填材料性能的主要因素:减水剂是影响充填材料流动性的主要影响因素,水泥次之,煤矸石的组成和微观结构决定了其对于料浆的流动性亦有一定的影响;影响充填材料凝结硬化后强度的主要因素为水泥的用量和减水剂的用量,煤矸石粉料(≤0.075 mm)的用量亦有一定的影响。通过研究分析得出了适合充填开采工况需求的高浓度高流动性(流动度达到305 mm)的充填材料配比,该配比的充填材料凝结硬化后具有良好的强度性能。

The high concentration and high fluidity of coal gangue cemented filling materials can not be well considered.In order to solve the problems that the filling materials in the existing filling and mining technology either affect the working environment after underground dehydration due to high water consumption(low concentration),or block the pump and pipe due to high concentration and poor fluidity,a certain amount of cement,coal gangue powder(≤0.075 mm)and superplasticizer are added to the cemented filling materials.The fluidity and strength properties of filling materials with different ratios were studied and analyzed by using the methods of orthogonal test and range analysis.The micro morphology,element composition,oxide content and mineral composition of coal gangue were analyzed by methods of scanning electron microscope SEM,EDS energy spectrum analysis,X-ray fluorescence spectrum analysis(XRF),X-ray diffraction analysis and Fourier transform infrared spectroscopy(FTIR),and the effects of the composition and microstructure of coal gangue on the macro properties were explored.The main factors determining the properties of filling materials are revealed:water reducing agent is the main factor affecting the fluidity of filling materials,followed by cement,and the composition and microstructure of coal gangue also have a certain influence on the fluidity of slurry.The main factors affecting the strength of filling materials after setting and hardening are the amount of cement,the amount of water reducer and the amount of coal gangue powder(≤0.075 mm).Through research and analysis,the proportion of filling materials with high concentration and high fluidity(fluidity up to 305 mm)suitable for the needs of filling and mining conditions is obtained.The filling materials have good strength properties after condensation and hardening.