冒落胶结充填体对崩落法矿石回收效果影响作用研究

Study on the Effect of Caved Cemented Filling on the Ore Recovery of Sublevel Caving Mining Method

龙首矿西二采区在下向分层胶结充填法转无底柱分段崩落法过程中,人工诱导强度较低的胶结充填体自然冒落形成覆盖层,而覆盖层废石块度对崩落法的矿石回收效果有着显著的影响作用。本文系统研究了冒落胶结充填体及扇形中深孔崩落矿石的块度分布规律,及其在放矿散体移动场中的二次破碎机理及特性。研究结果表明,尽管胶结充填体强度较低,但其在空场条件下冒落的散体尺寸以中等块度(>0.3 m)以上为主,即便是在放矿散体移动场中受外力作用而发生二次破碎,其小块(<0.1 m)比例增加的程度也十分有限,更不会被全部破碎成粉,而且扇形炮孔崩落的矿石平均块度要小于冒落胶结充填体的平均块度,这一结论是确保西二采区无底柱分段崩落法取得良好应用效果的关键所在。为进一步防止冒落胶结充填体过早破碎和提前混入矿石造成贫化,提出了减小崩落矿石块度与组合放矿相结合的技术方案。最后,在矿山开展了工程实践,验证了前期研究结论,为矿山无底柱分段崩落法取得全面成功奠定了良好基础。

In the process of downward stratified cementing filling to sublevel caving in a mine,the induced caving method is used to make the cementing backfill naturally caving to form overburden,the lumpiness of overburden waste has a significant effect on the recovery of ore.The lumpiness distribution of initial caved cemented backfill and blasted ore,and its secondary crushing characteristics in the moving field of ore-drawing are systematically studied.The results show that,al⁃though the strength of cemented backfill is low,the size of the caved block in open stope is mainly above medium size(>0.3 m),Even if the secondary crushing of the caved block occurs under the action of external force in the drawing field,the increase of the proportion of small pieces(<0.1 m)is very limited,and it will not be broken into powder completely,while the average lumpiness of the fan-shaped blasthole blasted ore is smaller than that of the caved cemented backfill,this con⁃clusion is the key to ensure the good application effect of sublevel caving in western NO.2 mining area of Longshou Mine.In order to prevent the premature crushing of the caved cementing backfill and the premature mixing of the ore to cause dilu⁃tion,a technical scheme to reduce the blasted ore lumpiness combined with combined ore-drawing is put forward.Finally,an engineering practice is carried out in the mine,and the conclusions of the previous study are verified,which lays a good foundation for the successful application of sublevel caving in the mine.