兰尖铁矿的矿石为钒钛磁铁矿,围岩和夹石主要为辉长岩与大理岩。矿岩硬度较大,但节理发育,除粗粒辉长岩、大理岩和一级品矿石外,可爆性均较好。我矿技术规程规定,矿石块度超过1.2米、岩石超过1.4米为大块,必须进行二次爆破后才能铲装。过去的二次爆破主要采用炮眼法,其缺点是飞石抛掷距离远,粉尘危害大,劳动强度高,在釆场工作线较短和人员密度大的情况下,容易发生事故。 Lanjian iron ore ore is vanadium titanomagnetite, wall rock and gravel mainly gabbro and marble. Mineral rock hardness, but the joint development, in addition to coarse-grained gabbro, marble and first-grade ore, the explosion is good. Mine regulations of mine regulations, ore block more than 1.2 meters, more than 1.4 meters rock for the large, must be carried out after the second blasting equipment. In the past, the second blasting mainly used the blasthole method. The disadvantage was that the flying stone was thrown far away, the dust was harmful, and the labor intensity was high. In the case of a shorter working line and a large staff density in the field, accidents easily occurred.