摘要
针对大海则千万吨矿井的绿色化低干扰排矸需求,提出了垮落带矸石浆体充填技术,以期在不影响矿井正常生产的前提下,实现煤矸石的安全、高效、绿色化处置。为确保该技术的可行及充填参数的有据可依,遂在大海则煤矿地面矸石山建立垮落带矸石堆积模型,研究2种质量分数矸石浆体在采空区垮落岩块间空隙内的流动扩散规律。研究结果表明:(1)矸石浆体在采空区垮落岩块空隙内的流动共分为3个时期,分别为淌流期、涌流期和渗流期,且3个时期相互关联,密不可分。(2)随着矸石浆体充填量的增加,动流坡度呈先减小而后增大的趋势,最终呈阶梯型分布,当浆体充填量达到176 m时,71.8%的矸石浆体第1阶梯动流坡度为7.5%,第2阶梯动流坡度为1.8%,75.3%的矸石浆体第1阶梯动流坡度为7.8%,第2阶梯动流坡度为2.1%。(3)矸石浆体在垮落带内流动具有阶段选择性,涌出点涌出的浆体先以淌流方式沿动流坡度在第1阶梯内流动,而后第1阶梯内的浆体再以渗流方式沿倾向方向向第2阶梯内流动,当浆体质量分数为75.3%时,浆体进入岩块间空隙的最小宽度约为10 mm,当浆体质量分数为71.8%时,浆体进入岩块间空隙的最小宽度约为7 mm,在第2阶梯内浆体如树枝分叉状依次充填岩块间的空腔及空隙,并在倾向边界和走向边界处形成浆体堆积点,其第1阶梯向第2阶梯渗流的浆体可达浆体总量的37.8%以上。(4)模型1和模型2内的浆体垂高分布特征基本一致,浆体垂高随着远离低位灌浆管出口整体上呈下降的趋势,浆体最大垂高2.11 m(1.77 m),位于倾向断面6.5 m(6.3 m)的第1阶梯内,与低位灌浆管出口的水平距离为0.5 m(0.3 m);浆体最小垂高0.797 m(0.669 m),位于倾向断面29.2 m(29.0 m)的第2阶梯中部,与低位灌浆管出口的水平距离为25.595 m(25.364 m)。(5)沿着矸石浆体的流动方向,矸石浆体中粗颗粒的占比呈降低的趋势,细颗粒的占比呈上升的趋势,矸石浆体的质量分数呈下降的趋势。模拟试验表明,采用矸石浆体低位灌浆充填,可以实现煤矸石的采空区排放,其充填规模与垮落岩块块度、矸石浆体浓度和矸石粒度组成有关。
In view of the demand of green and low-interference gangue discharge at Dahaize Ten-million-ton coal mine,the filling technology of gangue slurry in the caving zone has been put forward in order to achieve the safe,efficient and green disposal of coal gangue without affecting the normal production of the mine.In order to ensure the feasibility of the technology and the basis of filling parameters,a model of gangue accumulation in the caving zone has been established in the ground gangue dump of Dahaize coal mine to study the flow and diffusion law of two kinds of gangue slurry in the gap between caving rock blocks in the goaf.The results show that(1)The flow of gangue slurry in the gap of caving rock blocks in the goaf can be divided into three periods,i.e.,flowing period,gushing period and seepage period.The three periods are interrelated and inseparable.(2)With the increase of gangue slurry filling amount,the dynamic flow gradient first decreases and then increases,and finally presents a stepped distribution.When the slurry filling amount reaches 176 m~3,for 71.8%gangue slurry,the first step dynamic flow gradient is 7.5%and the second step dynamic flow gradient is 1.8%,and for 75.3%gangue slurry,the first step dynamic flow gradient is 7.8%and the second step dynamic flow gradient is 2.1%.(3)The flow of gangue slurry in the caving zone is stage selective.The slurry from the gushing point first flows within the first step along the flow gradient,and then the slurry in the first step flows toward the second step along the dip direction.When the mass concentration of slurry is 75.3%,the minimum width of the slurry entering into the gaps between rock blocks is about 10 mm.When the mass concentration of the slurry is 71.8%,the minimum width of the slurry entering into the gaps between rock blocks is about 7 mm.In the second step,the slurry,liking branching,successively fills the cavities and interstices between rock blocks,and forms some slurry accumulation points at the dip and strike boundaries.The slurry flowing from the first step to the second step can reach more than 37.8%of the total amount of the slurry.(4)The vertical height distribution characteristics of slurry in Model 1 and Model 2 are basically the same.The vertical height of slurry decreases as it is far away from the outlet of low grouting pipe.The maximum vertical height of slurry is 2.11 m(1.77 m),which is located in the first step of 6.5 m(6.3 m)inclined section,and the horizontal distance from the outlet of low grouting pipe is 0.5 m(0.3 m).The minimum vertical height of the slurry is 0.797 m(0.669 m),which is located in the middle of the second step of the inclined section 29.2 m(29.0 m),and the horizontal distance from the outlet of the low grouting pipe is 25.595 m(25.364 m).(5)Along the flow direction of the gangue slurry,the proportion of coarse particles in the gangue slurry decreases,the proportion of fine particles increases,and the mass concentration of the gangue slurry decreases.The simulation test shows that the filling scale is related to the size of caving rock,the concentration of gangue slurry and the composition of gangue particle size.
作者
朱磊
潘浩
古文哲
赵萌烨
张新福
徐凯
ZHU Lei;PAN Hao;GU Wenzhe;ZHAO Mengye;ZHANG Xinfu;XU Kai(China Coal Research Institute Co.,Ltd.,Xi’an 710054,China)
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2021年第S02期629-638,共10页
Journal of China Coal Society
关键词
垮落带
矸石浆体
浆体质量分数
低位灌浆
caving zone
gangue slurry
slurry concentration
low-level grouting
作者简介
朱磊(1982—),男,安徽阜阳人,高级工程师,博士。E-mail:103210851@qq.com
