摘要
骨料级配是膏体充填设计的关键参数,针对原始煤矸石粒度粗,不能直接用于制备煤矸石膏体充填的问题,采用室内试验与水硬化模拟相结合的方法,开展破碎煤矸石的级配优化设计研究。结果表明:现场取样的煤矸石干密度为1.614 g/cm^(3),比重为2.518,70%以上的颗粒粒径大于1 mm,属于块石、砾石,级配不合理;采用泰波理论对破碎煤矸石级配进行设计,在泰波指数n=0.3~0.7范围内,煤矸石的堆积密实度与n具有抛物线形式的关系;当n=0.35时设计的破碎煤矸石骨料具有最大的堆积密实度2.222g/cm^(3),75µm以下的细颗粒占14.2%,可达到膏体的制备标准;泰波指数与特征粒径还有较明显的线性关系,而与曲率系数cc和不均匀系数cu的关系不显著;利用VCCTL水硬化模拟软件,验证了级配n=0.35的煤矸石膏体28 d水化程度达0.78,且膏体的微观结构更致密,预测的力学性能更高,这与细颗粒的填充、成核等效应有关。从堆积密实度试验和水化模拟2个角度验证了级配优化设计的合理性。研究结果对煤矸石膏体充填的设计与优化提供了重要理论基础和指导意义。
The aggregate grading is a key parameter in the design of cemented paste backfill.In response to the problem that original coal gangue is coarse and cannot be directly used for preparing coal gangue paste,research on crushed coal gangue grading design and optimization for backfill are performed through laboratory experiments and hydration simulation.The results show that the dry density of coal gangue sampled on site is 1.614 g/cm^(3),with a specific gravity of 2.518.More than 70%of the particle diameter is greater than 1 mm,belonging to block stones and gravel,and the grading is unreasonable.Using the Taibol theory to design the grading of crushed coal gangue,within the Taibol index range of n is 0.3 to 0.7,the packing density of the crushed coal gangue has a parabolic relationship with n.When n=0.35,the de-signed crushed coal gangue aggregate has the maximum packing density of 2.222 g/cm^(3),with fine particles below 75µm accounting for 14.2%,which can meet the preparation standards of the paste.There is a clear linear relationship between the Taibol index n and the featured particle diameter,while the relationship for curvature coefficient cc and the non-uniformity coefficient cu is not significant.Using VCCTL hydration simulation software,it is verified that the hydration degree of coal gangue paste with the grading of n=0.35 reached 0.78 after 28 days.The microstructure of the paste was denser,with higher predicted mechanical properties,which are related to the filling and nucleation effects of fine particles.The rationality of gradation optimization design is verified from the perspectives of indoor experiment and hydration simulation.The study provides an important theoretical basis and guiding significance for the design and optimization of coal gangue paste fill.
作者
巴蕾
付瑞
王晶
卓庆奉
岑旺
肖柏林
BA Lei;FU Rui;WANG Jing;ZHUO Qingfeng;CEN Wang;XIAO Bolin(Ordos Vocational College;Inner Mongolia Yitai Coal Co.,Ltd.;Scholl of Civil and Resources Engineering,University of Science and Technology Beijing)
出处
《现代矿业》
CAS
2024年第4期230-235,共6页
Modern Mining
基金
国家重点研发计划项目(编号:2022YFC3004601)
鄂尔多斯市2021科技研发计划项目(编号:2021YY工120-50)。
关键词
煤矸石
膏体充填
管道输送
级配
堆积密实度
水化模拟
coal gangue
paste fill
pipeline transportation
grading
packing density
hydration simulation
