Diagnostic models of wind field and pollutant dispersion face difficulty when applied to complex terrain. Open-pit mines are an example of this difficult environment. To elucidate such difficulties, two models are developed and compared with one another. The first model is based on the prognostic Computational Fluid Dynamics-Lagrangian Stochastic (CFD-LS) paradigm, while the second model is based on the diagnostic CALifornia PUFF (CALPUFF) software. Two mine depths (100 [m] and 500 [m]) and three thermal stability conditions (unstable, neutral, and stable) are investigated using the two models. The CFD results showed that the skimming flow is only predicted under the neutral case, while more complex flow patterns emerge otherwise. Under the unstable case, the shallow and deep mines induce enhanced mixing downstream of the mine, resulting in substantial vertical plume transport and dilution of the pollutants released from the mine. Under the stable case, the plume from the shallow mine is restricted to the surface layer downstream of the mine. However, under the stable case, the plume from the deep mine rises into the substantial portion of the boundary layer due to the formation of a standing wave over and inside the mine. The results suggest that the CFD model can predict transport phenomena over open-pit mines reliably, so that the meteorological fields may be incorporated in operational models to improve the accuracy of their predictions. On the other hand, the CALPUFF model generally deviates from CFD-LS predictions, and the disagreement between the two models is the greatest when modelling the deep mine, under neutral/stable conditions, or when its solutions are considered close to the mine edge. Among many reasons, the variances appear to be related to the internal algorithms of the CALPUFF model to predict the wind eld structure appropriately. The results should caution practitioners considering diagnostic models for application over complex terrain, with opportunities to investigate such discrepancies at greater detail in follow up research.

Entrapment of pollutants in a deep open pit operating in a cold climate could occur due to atmospheric inversion. The process of air inversion is complex and requires thorough understanding in order to design a mine ventilation plan to remove trapped pollutants in open-pit mines operating in the arctic/sub-arctic regions. The objective of this research is to develop a model using computational fluid dynamics (CFD) tools for analysis of gaseous pollutant transport in deep, open pit mines under air inversion in arctic or subarctic regions.

Entrapment of pollutants in a deep open pit operating in a cold climate could occur due to atmospheric inversion. The process of air inversion is complex and requires thorough understanding in order to design a mine ventilation plan to remove trapped pollutants in open-pit mines operating in the arctic/sub-arctic regions. The objective of this dissertation is to develop a model using Computational Fluid Dynamics (CFD) tools for analysis of gaseous pollutant transport in deep, open pit mines under air inversion in arctic or subarctic regions. An Eulerian 3-D model was used for the development and validation of the CFD model of pollutant transport in an idealized open pit mine. No prior assumptions, turbulent or laminar, were considered for the nature of the flow. The 2-D model results indicated that air velocity, air temperature, diffusivity coefficient and slope angle were important controlling parameters in the inversion process. The flow regime was laminar at the origin, but as the flow progressed toward the center of the pit it changed to quasi-laminar and generated local eddies towards the pit bottom. The total energy of the quasi-laminar flow as well as the small local eddies was not enough to lift the inversion cap. However, a combination of quasi-turbulent flow and the local eddy transport resulted in removal of some of the pollutant mass from the pit bottom, either due to turbulent mixing, or due to advection. Presence of backflow may appear to be a logical mode of flow in deep open-pit mines in arctic regions. Next, the 3D model was validated using data from a selected open-pit mine. Influent air velocity, diffusivity coefficient, larger pit geometry were found to influence the retention and transport of pollutant out of the pit. The most important conclusion that was drawn from this research is that natural ventilation alone cannot remove the pollutants from an open pit or lift the inversion cap.

A better understanding of the microscale meteorology of deep, open pit mines is important for mineral exploitation in arctic and subarctic regions. During strong temperature inversions in the atmospheric boundary layer--which are common in arctic regions during the winter--the concentrations of gaseous pollutants in open pit mines can reach dangerous levels. In this research, a two dimensional computational fluid dynamics (CFD) model was used to study the atmosphere of an open pit mine. The natural airflow patterns in an open pit mine are strongly dependent on the geometry of the mine. Generally, mechanical turbulence created by the mine topography results in a recirculatory region at the bottom of the mine that is detached from the freestream. The presence of a temperature inversion further inhibits natural ventilation in open pit mines, and the air can quickly become contaminated if a source of pollution is present. Several different exhaust fan configurations were modeled to see if the pollution problem could be mitigated. The two dimensional model suggests that mitigation is possible, but the large quantity of ventilating air required would most likely beimpractical in an industrial setting.

Since the mining industry is still expanding, comprehensive information on the effects of mining activities on the environment is needed. This book provides information on biological and physico-chemical treatments of mining effluents, on factors affecting human health and on environmental effects that have to be taken into account by the mining industry when aiming for sustainable development of their industry. Further regulatory guidelines and legislation relevant to the decommissioning of mining sites are reviewed. Mining industry, consulting companies, and governmental agencies alike will find a wealth of valuable information in this book.

This volume gathers the latest advances, innovations, and applications in the field of mining, geology and geo-spatial technologies, as presented by leading researchers and engineers at the International Conference on Innovations for Sustainable and Responsible Mining (ISRM), held in Hanoi, Vietnam on October 15-17 2020. The contributions cover a diverse range of topics, including mining technology, drilling and blasting engineering, tunneling and geotechnical applications, mineral processing, mine management and economy, environmental risk assessment and management, mining and local development, mined land rehabilitation, water management and hydrogeology, regional Geology and tectonics, spatial engineering for monitoring natural resources and environment change, GIS and remote sensing for natural disaster monitoring, risk mapping and revisualization, natural resources monitoring and management, mine occupational safety and health. Selected by means of a rigorous peer-review process, they will spur novel research directions and foster future multidisciplinary collaborations.