充填体下切割天井一次爆破成井技术研究与应用

Research and application of slot raise under the fill with one-time grooved blasting technology

爆破成井是中深孔或深孔采矿方法中关键的一个工艺,主要包括分次或一次爆破成井方式。在中深孔采矿工艺中,切割天井是重要的采切工程,通常采用普通法、吊罐法或爬罐法进行施工,存在较大的安全隐患,并且掘进效率较低,严重影响矿山生产。近年来,三山岛金矿下向中深孔分段采矿面临充填体下中深孔采场切割天井的施工难题,研究了直孔掏槽法切割天井的一次爆破成井技术及应用效果。通过爆破参数计算,选用装药孔直径Φ65 mm、补偿空孔直径Φ110 mm的钻孔孔径,综合考虑确定了装药孔与空孔之间的距离为0.3 m,能够满足爆破补偿空间及自由面的要求。结合矿岩稳固条件,选用9孔掏槽方式,进而制定了炮孔布置方案,即掏槽孔设计1个中心装药孔,12个空孔作为补偿孔,辅助孔4个,周边孔12个,共计29个孔。在确定炮孔堵塞长度、炸药选择、装药结构、微差时间、起爆顺序等工艺参数之后,开展了切割天井的现场工业试验。试验表明:切割天井一次爆破成井方案是可行的,爆破块度均匀,无大块和过粉现象,爆破扰动小,爆破成形规格满足设计要求,爆破效果良好,为其它类似条件的切割天井一次爆破技术应用提供了参考依据。

Cut patio construction was a critical process in the medium-deep hole or deep hole mining methods,which mainly included staged blasting or one-time grooved blasting.Cut patio was essential in the medium-deep hole mining technology.The common method,the conventional raising,cage raising and climber raising method was usually used to construct the cutting patio,which has great safety risks and low excavation efficiency,which seriously affects the mine production.In recent years,Sanshandao Gold Mine has researched downward sublevel filling mining with medium and deep hole blasting.This research was currently facing the problem of cut patio construction under the backfill roof.This study demonstrated a one-time grooved blasting method fitting the backfill roof condition and its application.By comparing the characteristics of the straight-hole cutting method and the blasting crater method,the straight-hole cutting method was selected for the cut patio construction.By calculating blasting parameters,the diameter of the charging hole wasΦ65 mm,and the diameter of the compensation hole wasΦ110 mm.The distance between the charging and empty holes was 0.3m,which could meet the requirements of blasting compensation space and free surface.In consideration of the surrounding rock stability conditions,a nine-hole cutout method was selected,containing 29 holes,where the cutout hole was designed with 1 central charging hole,12 empty holes as compensation holes,4 auxiliary holes,and 12 peripheral holes,after determining the blast hole plugging length,explosive selection,charge structure,differential time,detonation sequence and other process parameters,an in-situ industrial test of cut patio construction was carried out.The industrial test showed that the one-time grooved blasting plan for patio construction was feasible.The blasting rock particle size is uniform with no large blocks and excessive powder,the blasting disturbance is minor,and the blasting patio dimensions meet the design requirements.Overall,this test provided experiences and a reference basis for other one-time grooved blasting technical applications with similar conditions.