The Research Of Mining Methods In North Region Of Shuangyashan Iron Mine

The steeply inclined ore body in North region of Shuangyashan has the poor stability. The original mining method is short-hole shrinkage method which causes low capable mining productions, poor safety condition and low mining rate, that seriously affect the economic benefits of deposit mining, especially for Shuangyashan steel plant. Therefore, there is an urgent need to find a safe and high efficient mining method according to geological features of deposit,existence of ore body and mining conditions to achieve the"four low and one high"(low loss, low dilution, low cost, low event hidden trouble and high efficiency) goal of mining.This paper summarizes the geological features, characters of ore and rocks, geological ore-amounts, water and engineering geology and mining conditions of the north region of Shuangyashan iron mine in detail. And we investigate rock mass structural planes, determine point load strength and flowing parameter of loose body on site, grade stability of rock mass according to the investigated data of structure planes and the point load index. On this basis, it analyses process of ore body caving and principle of low dilution and loss caving according to induced caving technique and ore drawing theory in stochastic flowing, so as to put forward various mining methods to adapt to different conditions of ore body. For the thick ore body, QZJ-100B down-the-hole drill is used for single sublevel drilling to induce upper ore body dropping naturally, thus forming floor pillar caving mining method with induced caving. For the medium thick ore body, using low dilution and loss sublevel caving. For the thin ore body, using combination method of open stope and caving when stability of surrounding rock is better; using original method (short-hole shrinkage method) and bolt support when stability of surrounding rock is worse. In this paper the method of shotcrete rockbolt mesh in preparation roadway, which ensures the effective implementation of new mining methods, is also studied. These mining methods and support technique, which are fit for this mine, are being implemented at present. The application of these techniques will effectively improve stope production and safety production condition.