小汪沟铁矿露天转地下分区高效开采技术

针对小汪沟铁矿上部矿体规模较小、露天转地下自由作业空间小、首采矿段的回采工作面不够充足、难以实现设计产能的问题，在分析矿岩可冒性以及矿体赋存条件的基础上，提出了基于岩体持续冒落面积的3分区开采方案，并依据顶板围岩冒落范围以及岩移影响范围分析了分区开采的安全条件。该方案在确保生产安全的前提下，将小汪沟铁矿的地采产能由设计的100万t/a提高到280万t/a。生产实践表明，利用顶板围岩的冒落特性提出的多分区开采技术，扩展了露天和地下同时开采的作业空间，不仅实现了小汪沟铁矿露天转地下产能的大幅度提高，也实现了安全高效的开采目标，同时也为类似铁矿山实现高强度开采提供了有效途径。

High Efficient Divisional Mining Technology during Transition from Open-pit to Underground Mining in Xiaowanggou Iron Mine

There are some problems in Xiaowanggou Iron Mine，such as small-scale upper ore-body，narrow working space from open pit to underground mining，and deficient stopes in the first mining section，and hard to reach the expected productivity etc.In view of these problems，and on the basis of analyzing the caving possibility of ore rocks and the occurence conditions of orebody，a new scheme of three dividions based on the continuous caving of rocks was proposed.And then，according to the ranges of roof surrouding rock caving and rock movement，the safety of mining were analyzed.On the premise of keeping safety in mining，this scheme makes the productivity of underground mining in Xiaowanggou Iron Mine increase from 1 million t/a in original to 2.8 million t/a.Finally，the production practice showed that the multi-division mining technology based on the characteristics of roof surrounding rock caving expanded the work space as the simultaneous mining of open pit and underground.It not only greatly improves the productivity from open pit to underground in Xiaowanggou Iron Mine，but also achieves the exploration target with safety and efficiency.Meanwhile，it provides an effective way for high efficient exploitation of similar iron mines.