Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines, Northeastern University, Shenyang, China.
Business Administration Department, Liaoning Radio and TV University, Shenyang, China.
PLoS One. 2020 May 20;15(5):e0232640. doi: 10.1371/journal.pone.0232640. eCollection 2020.
The gently inclined medium-thick orebody is generally viewed as difficult to extract. This paper presents a sublevel open stoping using long-hole with back filling method, particularly for inclined medium-thick orebodies. This method not only changes the temporal sequence of ore stoping and realizes transportation using gravity and trackless devices, but also improves production capacity and efficiency. Nonetheless, this method also has some disadvantages; for example, the orebody has more contact with country rock, and the method has a more complex loss and dilution process. This paper starts with the analysis of the results of physical simulation experiments that examine the interactive relationship among the lower stope footwall dip angle, the footwall surface roughness, draw point interval and production blast ring and concludes their influence on the ore-recovery ratio in each production cycle. Secondly, based on physical simulation results, the multivariate linear fit was carried out on the SPSS using the dimensional analysis method. Thus a statistical model was developed for investigating the influence of gently inclined medium thick orebody, the footwall dip angle, the footwall roughness and interval of draw points on the recovery ratio, which can accurately forecast the ore-recovery ratio under different parameters in the physical simulation process. The optimal structural parameters obtained from physical simulation and statistical analysis was then applied to industrial experiments. Based on the 3D laser scanning during in-suit experiments, it was found that the lower stope had an 82% recovery ratio and an 18% dilution ratio, while the upper stope had a recovery ratio of 85% and a dilution ratio of 12%. Moreover, the production capacity could be up to 600t/d. The physical simulation and industrial experiments both demonstrate that the new mining method can be adopted for the safe and efficient mining of gently inclined medium-thick orebodies.
缓倾斜中厚矿体通常被认为难以开采。本文提出了一种采用深孔嗣后充填法的分段空场采矿法，特别适用于倾斜中厚矿体。这种方法不仅改变了采场回采的时序，实现了重力和无轨设备运输，而且提高了产能和效率。然而，该方法也存在一些缺点；例如，矿体与围岩的接触更多，方法的损失和贫化过程更为复杂。本文首先从物理模拟实验的结果分析开始，研究了下盘底板倾角、底板表面粗糙度、出矿点间距和生产爆破环之间的相互关系，得出了它们对每个生产周期的矿石回采率的影响。其次，基于物理模拟结果，采用 SPSS 中的多元线性拟合，使用量纲分析方法对数据进行拟合，建立了统计模型，研究了缓倾斜中厚矿体、下盘倾角、下盘粗糙度和出矿点间距对回采率的影响，该模型可以准确预测物理模拟过程中不同参数下的矿石回采率。然后将物理模拟和统计分析得到的最优结构参数应用于工业试验。通过现场试验中的三维激光扫描，发现下部采场的回采率为 82%，贫化率为 18%，而上部采场的回采率为 85%，贫化率为 12%。此外，产能可达 600t/d。物理模拟和工业试验均表明，该新采矿方法可用于安全高效开采缓倾斜中厚矿体。
