Advanced tools for analyzing and predicting the performance and durability of paste backfill under different thermal conditions

点击翻译按钮获取中文摘要

Cemented paste backfill (CPB), a mix of tailings, binder and water, is extensively used in the mining industry. Its main purpose is to ensure the stability of underground openings, safe and maximum ore recovery, and also to provide an environmental-friendly means of underground disposal of potential acid generating tailings. However, many fundamental aspects, such as the impact of temperature on the performance (mechanical stability, quality of the CPB) and durability (resistance to sulphate attack: sulphate attacks the binder and destroys its binding effect) properties are still poorly understood. Furthermore, it is well known that in a broad range of engineering problems the change of material properties and accumulation of damage are not only caused by mechanical loads, but also by temperature and moisture induced loading as well as chemically aggressive factors (e.g., sulphate) or various combinations of these processes. However, the level of knowledge on these interactions between thermal, chemical, hydric and mechanical processes in CPB is still very limited. Thus, an accurate prediction of the performance and durability properties of CPB needs a deep understanding of the effect of temperature on these properties and of the coupled thermo-chemo-hydric-mechanical (TCHM) mechanisms that occur in CPB, and the development of tools that will predict them. Hence, through the combination of experimental and modeling techniques, this research program will focus on the following objectives: (i) understand the impact of temperature and coupled TCHM loadings on the performance and durability properties of CPB; (ii) develop and validate advanced optimization tools that will make it possible to prepare optimal CPB recipes for any curing temperature; and (iii) develop and validate advanced TCHM models to predict the mechanical stability and the durability of CPB under various TCHM loading conditions. This proposed research will benefit the research community, mining industry, educational institutions, civil engineering firms, and Canadian community by providing of fundamental knowledge and advanced tools or techniques for sustainable and safe mining.