Characterisation of secondary fragmentation processes using a combination of laboratory experiments and numerical analysis

建立破碎模型对于提供可靠的破碎估计以供矿山规划使用至关重要。该模型将需要提供在采矿过程的各个阶段预计产生的岩石块的大小范围和分布的量度。对于块状和盘状洞穴开采，从抽采点提取的块状的大小和形状是特别重要的，因为生产设备和抽采点的布局必须适应产生的块状。在矿山可行性期间评估的破碎预测与崩落过程中遇到的预测之间存在差异，这突出表明需要更好地了解二次破碎过程和机制，以促进资源的经济和可持续开采。为了满足这一需求，行业合作伙伴提供了资金和实物支持，以支持不列颠哥伦比亚大学（UBC）的研究，该研究将重点放在整合数值分析和实验室实验上，以研究与崩落矿柱相似的不同载荷条件下岩石破碎相关的破坏和粉碎过程。该研究将使用不同实验室规模的受控实验来校准和约束一系列模拟脆性断裂过程的高级数值分析（使用最先进的FEMDEM代码ELFEN）。这些将用于开发新的工具和关系，以表征块状和盘状洞穴矿设计的二次破碎。在此基础上，这里提出了一项为期三年的NSERC合作研究与开发（CRD）拨款，将致力于将复杂的数值方法与实验室实验相结合，以提高我们对地下大规模采矿方法破碎过程的认识及其对安全和经济采矿的贡献。CRD的主要目标将集中在基于地质统计学的离散裂缝网络（DFN）模型，与脉密度相关的岩石破坏效率，以及用实验结果校准建模结果。

The development of a fragmentation model is critical to provide reliable estimates of fragmentation for use in mine planning. The model would need to provide a measure of the range and distribution of the sizes of the rock blocks expected to be produced at various stages during the mining processes. For block and panel cave mining, the size and shape of the blocks extracted from the drawpoints is of particular importance, since the production equipment and the drawpoint layouts must accommodate the resulting blocks. The disparity between fragmentation predictions assessed during mine feasibility and those encountered during caving underscore the need to better understand secondary fragmentation processes and mechanisms to facilitate the economic and sustainable mining of the resource. To address this need, funds and in-kind support have been provided by industry partners to support research at the University of British Columbia (UBC) that will focus on integrating numerical analyses and laboratory experiments to study the failure and comminution processes associated with rock fragmentation under different load conditions that parallel those encountered in a caved ore column. The research will use controlled experiments at different laboratory scales to calibrate and constrain a series of advanced numerical analyses simulating brittle fracture processes (using the state-of-the-art FEMDEM code ELFEN). These will be used to develop new tools and relationships for characterising secondary fragmentation for block and panel cave mine design. Building on this, a three-year NSERC Collaborative Research and Development (CRD) grant is proposed here that will work towards integrating sophisticated numerical methods with laboratory experiments to improve our knowledge of fragmentation processes for underground mass mining methods and its contribution to safe and economic mining. The key objectives of the CRD will focus on geostatistics based Discrete Fracture Network (DFN) models, rock breakage efficiency associated with veins density, and calibration of modelling results with experimental results.