In order to solve the problem of large ore loss dilution in the mining cutting and mining transition period of the bottomless pillar segmented caving method in Heishan iron ore,the reasons for the occurrence of blind blocks and the large dilution of ore loss in this period are analyzed,and it is believed that the blocking effect of the lower horizontal cutting edge wall on the upper horizontal hole distribution,the unilateral consideration of the space compensation of the cutting groove in the production and the increase of the free space,ignoring the subsequent influence of the cutting edge wall on the upper level,are the main reasons for the failure of the fan-shaped free surface and the formation of blind blocks.Because the large blocks are mainly gathered at the top of the discharge body,with the progress of ore drawing,the large blocks reach the eyebrow line in advance,and the next blasting has to be organized,resulting in the loss of secondary ore volume;at the same time,the existence of large blocks leads to the small pieces of waste rock in the upper overburden layer along the gap between the blocks to reach the ore outlet first,resulting in a large ore dilution rate.Starting from the perspective of eliminating the blind block and controlling the dilution of ore loss,according to the projection of the upper and lower horizontal cutting lanes,the transition relationship in each case is clarified,and according to the position relationship between the upper and lower horizontal cutting lanes,a reasonable optimization of the hole distribution parameters of the cutting roadway and the control method of ore loss and dilution of the blind block are proposed.Through on-site practice,the ore dilution rate and loss rate of underground mining cutting and mining transition period in Heishan iron ore mine were reduced by 26.2％and 29.3％.respectively.which provided a reference for mine production under similar conditions.
关键词
无底柱分段崩落法/损失贫化/切割巷/盲区块/炮孔参数
Key words
sublevel caving method without pillar/loss and depletion/cutting lane/blind area block/hole parameter
维普
万方数据