【作者】 余健；

【导师】 古德生；

【作者基本信息】 中南大学 ， 采矿工程， 2008， 博士

【摘要】 增大结构参数是现代无底柱分段崩落法的发展方向。本文结合大红山铁矿的建设项目,研究了高分段大间距无底柱分段崩落法的回采工艺。工业试验证明,分段高度由我国目前的15m增加到20m,可降低采切成本25%,单步距崩矿量增加到7000t,有效地提高了采场生产能力降低了出矿损失贫化。这一研究成果标志着我国无底柱分段崩落法的分段高度进入到20m的新阶段,拉近了与西方先进国家同类采矿方法技术水平(30m分段高)的距离。贫化损失指标的预测是无底柱分段崩落法放矿理论研究的重要内容,本文在原有放出体前方废石混入贫化指标计算的基础上,进一步研究了放出体顶部和侧面废石混入造成矿石贫化损失的原因,推出了放出体顶部和侧面废石混入造成贫化率的计算公式,各种贫化情况下回收率的计算公式,完善了端部放矿理论贫化损失指标的计算体系,为全面系统地进行贫化损失指标的预测奠定了理论基础。分段高度、进路间距和崩矿步距的不同组合,对放矿损失贫化指标影响重大。本文研究了结构参数优化的方法,在以“回贫差”最大化为目标函数,确定崩矿步距的基础上、建立了单位工业储量盈利最大化和单位精矿盈利最大化为目标函数的数学模型。改变了传统的仅考虑贫化损失指标最佳确定结构参数的方法,开辟了从保障矿床开采整体经济效益最大化确定结构参数的新途径。理论研究和实验都证明,不(低)贫化放矿可大幅度地降低出矿贫化率。但是目前的放矿管理方式与复杂的生产实际不适应。本文改变了过去的组合截止品位放矿管理办法,大胆使用了定量放矿管理方案。工业试验表明,采用定量放矿管理简单易行,完全可达到不(低)贫化放矿的目的,放出矿石的贫化率可控制到5%以内(不包括底部和次底部分层放矿),这种放矿管理方式为不贫化放矿的推广应用带来了新的发展契机。大红山铁矿上盘岩石自然崩落规律研究表明,主采区基建采场回采期间,需采用强制崩落顶板形成覆盖岩石;基建采场回采完毕,可采用自然崩落与强制崩落相结合的方法形成覆盖岩层,顶板岩层的自然崩落高度达到120m;持续采场回采完毕,矿体上盘岩层已完全形成自然崩落机制,可利用自然崩落顶板岩层形成覆盖岩层,顶板岩层最终的崩落高度达到160m;中部1和中部2采区完成第1步回采后,顶板岩层就可形成自然崩落机制,可依靠自然崩落形成覆盖岩石。更多还原

【Abstract】 The enlarged structural parameter represents the development trend of modern pillarless sublevel caving. Cooperating with the construction project of Da Hong San Iron Mine, this dissertation studied the mining technology of high sublevel and large space drive interval of pillarless sublevel caving. The industrial experiment turned out that the sublevel height was increased from 15m to 20m, which could reduce 25% of the recovery and cutting costs, the ore volume of each step of blasting was increased by 7000t, the mining productivity was improved, and the ore loss and dilution rate was reduced effectively. The research achievements marks that sublevel height of pillarless sublevel caving in our country comes into a new state (20m high), the distance of similar mining technology level is shortened between our country and advanced western countries (30m high).The prediction of ore dilution and loss rate is one of the important part of drawing theory on pillarless sublevel caving. Based on the former resesrch about the dilution calculation of ore interfusion, a further research that the top and flank wastes were mixed into the drawing body causing loss and dilution of ore was made on in this dissertation. The calculation formula of top and flank wastes mixed dilution and recovery rate was worked out. And the system for loss and dilution rate calculation of side drawing theory is improved greatly, thus the theoretical basis for systematic predicting ore loss and dilution rate was established.Usually ore drawing dilution rate is influenced by the different combination of sublevel height, drive interval and step of blasting. The method of structural parameter optimization was studied in the dissertation. After objective function of the maximization of difference between recovery and dilution rate was founded to confirm step of blasting, the objective function of maximization of industrial unit of reserves gain and unin of concentrate gain were established as mathematical model. The traditional method only considering loss and dilution rate to define structural parameter was changed, a new approach was created to define structural parameter for the purpose of gaining the maximal bebefit in the deposit exploitation.Theory study and the experimental test turned out that ore-drawing dilution rate could be greatly reduced by low dilution ore-drawing. But nowadays ore-drawing managemen mode and the complicated conditions in practical production are not matched well. The dissertation changed the past combined cutoff grade ore-drawing, ration ore-drawing was applied for the first time.The industrial experiment showed that the mode of the ration ore-drawing is applicable with both simplicity and easiness, and the goal of low dilution ore-drawing could be well obtained. The dilution ratio of drawn ore could be controlled within 5% (not including the ore-drawing in the bottom and in the upper bottom sublevel). The new opportunity for the popularization and the application of the low dilution ore-drawing would be brought by the ore-drawing management mode.The study on the regularity of top rock level caving in Da Hong San Iron Mine showed that in mining in the newly-built mining quarters of the main mining field, blasting the top rock of body should be adopted in the formation of the covering rock. When mining in the newly-built quarters was finished, the combination of the two ways-level caving and blasting could be applied to form the covering rock. The height of the level caving of top rock was 120m. When mining in the following mining quarters were finished, the mechanism of level caving was completely formed in the top rock of body, and then the covering rock was formed through the use of the level caving of the top rock, the final height of the level caving reached 160m.In the middle mining field 1 and 2, after the first step mining were finished, the mechanism of the level caving in the top rock of body was formed and covering rock was formed by level caving afterwards.更多还原