全尾砂胶结充填体分层特性试验研究

Experimental Study on Delamination Characteristics of Full Tailings Cemented Backfill

在分段或阶段嗣后充填采空区中全尾砂胶结充填体的分层现象较为常见。基于此,以程潮铁矿所取尾砂及相关基础资料为试验基础,采用一次充填分别制作灰砂比为1:4、1:6、1:8、1:10的全尾砂胶结充填体试样,进行单轴压缩胶结充填体超声波波速监测试验,获取胶结充填体试样破坏荷载及超声波波速,探讨不同灰砂比的充填体试样超声波波速分层变化特征,结合颗粒粒级特征,揭示全尾砂胶结充填体分层机理。试验结果表明:(1)通过对不同灰砂比、不同分层测点进行对比分析,得出超声波波速变化规律为:①v(上)>v(中)>v(下),②v(1:4)>v(1:6)>v(1:8),v(1:10);(2)结合颗粒粒级特征,表明全尾砂胶结充填体的分层变化特性是由于充填体试样内部颗粒间的排列方式及紧密程度之间的特征而导致;(3)全尾砂胶结充填体分层现象对充填体的强度影响较大,颗粒密实程度越好、颗粒排列越均匀,越能更好地对其强度进行表征。研究结果可为程潮铁矿极其类似矿山的充填生产实践提供有效指导意见。

It is common to fill the gob with full tailings cemented backfill in different stages.Based on this,taking the tailings from Chengchao Iron Mine and relevant basic data as the basic data,full tailings cemented backfill samples with ash sand ratio of 1:4,1:6,1:8 and 1:10 were prepared respectively by one-time filling,and the uniaxial compression cemented backfill ultrasonic monitoring test were carried out,to obtain the failure load and ultrasonic wave velocity of cemented backfill samples,and to discuss the characteristics of ultrasonic wave velocity delamination of filling samples with different lime-sand ratios.Combined with the particle size characteristics,the delamination mechanism of full tailings cemented filling was revealed.The test results show that:(1)By comparing and analyzing different lime-sand ratios and different stratified measuring points,the variation law of ultrasonic wave velocity is obtained as follows:①v(up)>v(middle)>v(down),④V(1:4>v(1:6)>v(1:8)>v(1:10)(2)Combined with the particle size characteristics,it is indicated that the stratification characteristics of the full tailings cemented filling body are caused by the arrangement and tightness of the particles within the backfill body sample.(3)The delamination phenomenon of the full tailings cemented filler has a greater impact on the strength of the filler.The better the density of the particles and the more uniform the particle arrangement,the better the strength can be characterized.The research results can provide effective guidance for the filling production practice of similar mines like Chengchao iron mine.