Quantification of unplanned ore dilution associated with longitudinal sublevel stoping - Development of new numerical-empirical models

在全球竞争激烈的矿物市场上，矿山继续面临着降低成本的压力。减少采矿成本的一个办法是减少矿石的稀释。计划外的矿石稀释直接影响到采场的成本，并最终影响到采矿作业的盈利能力。贫化的经济影响是由于与运输和处理几乎或没有矿物价值的废物或低品位岩石有关的费用。由于提取废石而产生的矿石贫化现象所产生的较大采场体积的回填所需的额外时间也可能导致生产延迟、采矿计划的改变，并可能导致开发恢复成本的增加。该项目的目标是通过建立新的数值-经验贫化模型，针对预期的采场超冲和矿山调度，对与纵向分段回采方法相关的计划外矿石贫化（或超冲）进行量化。已确定的影响非计划贫化的因素，如诱发应力环境、采场几何形状和采矿顺序中的采场设置，都要考虑在内。项目案例研究将是Agnico Eagle Mines Limited位于魁北克省Abbitibi地区的Lapa矿。该研究成果将适用于采用纵向分段回采法开采深孔急倾斜板状矿带的地下矿山。这种采矿系统在加拿大、美国、墨西哥、澳大利亚和南美洲都很常见。

In a global competitive minerals market, there is continued pressure on mines to reduce costs. One approach to reducing mine costs is by the reduction of ore dilution. Unplanned ore dilution has a direct influence on the cost of a mine stope and ultimately on the profitability of a mining operation. The economic impact of dilution is due to costs associated with the transportation and treatment of waste or low grade rock having little or no mineral value. The additional time required for the backfilling of the larger stope volumes produced by the occurrence of ore dilution due to the extraction of waste rock can also lead to production delays, changes to the mining schedule, and potentially, development rehab costs. The goal of this project is to quantify unplanned ore dilution (or overbreak) associated with longitudinal sublevel stoping method, by establishing new, numerical-empirical dilution models for stope and orezone design, with respect to anticipated stope overbreak and mine scheduling. Identified factors influencing unplanned dilution such as induced stress environment, stope geometry, and the stope setting within the orezone extraction sequence are to be considered. The project case study will be the Lapa Mine of Agnico Eagle Mines Limited located in the Abbitibi region of the province of Quebec. The project findings will be applicable to underground mines employing longitudinal, sublevel stoping to extract steeply dipping, tabular orezones with longhole mining. Such mining systems are commonly found in Canada, USA, Mexico, Australia and South America.