毛公铁矿大结构参数无底柱分段崩落法多分段放矿实验

Multi-sublevel Ore Drawing Test of Non-pillar Sublevel Caving Method with Large Structural Parameters in Maogong Iron Mine

针对毛公铁矿生产中矿石回收率低、崩落矿石放出量少的问题,依据其采场结构参数,进行了1.6 m、1.8 m 2种崩矿步距条件下矿石回收、矿石残留体形态及其形成过程的物理相似模拟放矿实验。实验结果表明:首采分段放矿时,矿石回收率基本稳定在40%~50%;第2分段以后的放矿中,矿石回收率稳定在70%~90%,混岩率稳定在35%左右;上一分段脊部残留矿石将在下一分段逐渐回收;放矿过程中正面废石会较早混入放矿过程,造成矿石贫化;综合分析实验结果得出:1.8 m崩矿步距矿石回收率优于1.6 m。

In view of the issues of the lower ore recovery rate and less ore drawing in Maogong Iron Mine,the physical simulation experiments based on the stope structure parameters of the iron ore were carried out for exploring ore recovery,the shape of the residual ore body and its forming process at the conditions of the ore caving slice with 1.6 m and the 1.8 m.The results showed that the ore recovery rate was ranging from about 40% to 50% at the first caving sublevel and is at about 70% ~90% in the following sublevels with mixing rate of about 35%.The ridge residual ore was gradually recovered in the next sublevel; Waste rock in front of the caved ore body was mixed earlier into the process of ore drawing and caused ore dilution.Comprehensive analysis showed that the ore recovery rate of 1.8 meter caving step space is better than that of 1.6 meter.