Characterizing the effect of micro and macro heterogeneity of rock on its comminution behaviour

矿床几何特征的空间变异性会对采矿项目的经济、矿山规划、加工和废物管理产生重大影响。考虑到粉碎过程中使用的大量能源，很好地了解矿床几何冶金特征的空间变异性可以极大地优化采矿和加工活动中的能源消耗。需要进行大量的试验来表征和描绘矿体内不同的几何冶金域。点荷载强度指数试验在地质力学中得到了广泛的应用，是一种廉价的试验，可以在大范围的岩石样品上进行，也可以由矿山工作人员自己进行。可以进行大量的试验，以统计代表整个矿体。一些实验分析表明，点载荷指数试验可以与矿石的破碎特性(落锤试验、结合功指数等)相关联。这是破碎机和凹磨机模型设计所必需的。其他研究表明，岩石的机械强度与矿石破碎特性之间的关系很差，并表明岩石力学试验不能提供磨矿行为的信息，甚至不能提供颗粒释放水平的信息。这项研究项目的主要目的是确定岩石的微观和宏观性质(如强度、矿物成分、粒度分布、微裂缝)如何影响岩石在粉碎过程中的响应。

The spatial variability of geometallurgical characteristics of an ore deposit can significantly influence the economic, mine planning, processing and waste management of a mining project. Given the significant amount of energy that is used in the comminution process, a good understanding of spatial variability of geometallurgical characteristics of an ore deposit could highly optimize the energy consumption in the mining and processing activities. Large numbers of tests would be required to characterize and delineate different geometallurgical domains within an ore body. The Point Load strength index test is widely used in geomechanics and is an inexpensive test that can be conducted on a large range of rock samples and by the mine staff themselves. The test can be carried out in a large quantity to statistically represent the entire ore body. Some experimental analyses have shown that the Point Load Index test could be correlated with the ore breakage characteristics (drop weight test, Bond Work index, etc.) which are required for design of crushing and SAG mill modelling. Other investigations have shown poor relationships between the mechanical strength of rock and the ore breakage characteristics and indicated that the rock mechanics tests do not provide information regarding grinding behavior down to the particle liberation level. The main objective of this research project is to determine how the micro- and macro- properties of rock (e.g. strength, mineralogical composition, grain size distribution, micro-cracks) can influence the response of rock during the comminution process.