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产市场中，矿山继续面临降低成本的压力。降低采矿成本的一种方法是减少矿石贫化。计划外矿石贫化直接影响采矿采场的成本，最终影响采矿作业的盈利能力。贫化的经济影响是由于运输和处理几乎没有矿物价值的废物或低品位岩石所产生的成本。回填因开采废石而发生矿石稀释而产生的较大采场体积所需的额外时间，也可能导致生产延误、采矿时间表改变，以及潜在的开发修复成本。该项目的目标是通过建立新的关于预期的采场超采和采矿调度的采场和矿带设计的数值-经验贫化模型，来量化与纵向分段采矿法相关的计划外矿石贫化(或超采)。应考虑已确定的影响非计划稀释的因素，如诱发应力环境、采场几何形状和矿带开采顺序内的采场设置。项目案例研究将是位于魁北克省阿比提比地区的Agnico Eagle Mines有限公司的Lapa矿。该项目成果将适用于采用纵向分段采矿法的地下矿山，通过深孔采矿来开采急倾斜、板状矿带。这样的采矿系统在加拿大、美国、墨西哥、澳大利亚和南美洲很常见。

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.