无底柱分段崩落法矿石覆盖层回收实验

攀钢兰尖铁矿从露天转入地下后采用无底柱分段崩落法进行开采,并在顶部分段预留了40 m左右的矿石覆盖层以保证下部分段回采的安全.为了探究最佳的回收方式回收预留在采场的这部分矿石覆盖层,设计了无贫化、低贫化、截止品位以及按步距崩矿量100%的比例出矿方式,并进行回收模拟实验.通过对各方案放矿后的回收率、贫化率及放矿后矿岩界面的完整度比较分析得出,采用无贫化放矿方式带来的经济效益最佳并且放矿后矿岩界面相对完整,对下面分段继续回收纯矿石创造了条件,为类似矿山矿石覆盖层回收方案的选择提供参考.

Experiment of Recovery Method for Ore Overburden in Sublevel Caving

Pangang Lanjian Iron Mine used sublevel caving method after open-pit turned to underground mining. In order to ensure the safety of mining in lower segment， around 40m ore overburden had been set aside at the top segment. To explore the best way to recover ore overburden that had reserved in the stope， similar physical simulation experiment which includes the way of no dilution drawing， low dilution drawing， cut-off grade drawing and step away from the collapse of the amount of ore to 100% was designed in laboratory. Through the comparative analysis of recovery rate， dilute rate and the integrity of ore rock interface， it is concluded that the use of no dilution drawing method in sublevel caving generates the best economic benefit， which provides reference for similar mines about recovery method of ore overburden.