Technological and Environmental Innovations for Sustainable Mining Operations

Abstract

In the modern mining industry, sustainable mine operation becomes an inevitable option. Facing lower ore grade, more complex ore deposit, unstable commodity market, and strict regulations, mining corporates must find the solution to make their portfolio economically attractive. One of the biggest challenges for mine operation is how to improve operational efficiency under the circumstance of high uncertainties. These higher uncertainties originate from the variability of geological material and human intervention in the decision-making process. Advances in technologies allow the mine to operate under more environmentally friendly and socially responsible scenarios within a scheme of process optimization and cost-reduction. This dissertation investigates some innovative technological applications for sustainable mining operations. Four specific aims are closely connected and integrated into the dissertation within the boundary of two perspectives: 1) technological applications for economic sustainability based on Mine-to-Mill optimization and 2) environmental application for socio-ecological sustainability by reducing the dust generation at the tailings storage facilities (TSFs). The first article Use of drilling performance to improve rock-breakage efficiencies: A part of mine-to-mill optimization studies in a hard-rock mine explains a part of the ore characterization stage, rock-breakage characterization, in the Mine-to-Mill optimization scheme. This study proposed a prediction model of rock-breakage characteristics such as tensile strength and Bond Work Index (BWI) based on blasthole drilling performance. The adjusted penetration rate (APR) was introduced to normalize the raw data from measurement while drilling (MWD). Based on the results of a series of laboratory experiments, the prediction models for rock-breakage efficiency during crushing and grinding were established. The result of this study can expand to field application by showing the thematic map of downstream energy consumption using the APR from blasthole drilling. The second article Quantification of rock mass weathering using spectral imaging illustrates a part of the ore characterization stage in the Mine-to-Mill optimization scheme in terms of rock mass structural characteristics. This study proposes an innovative method, narrow-band multispectral (NBMS) imaging, to quantify the expected hazard on mine slopes. This study aims to delineate the weathered area of the rock mass, which has been considered as an important factor in slope stability and blast fragmentation. Based on the band-ratio approach with visible and near-infrared (VNIR) hyperspectral imaging, the best configurations of spectral bands were determined. The quantified weathering level from NBMS imaging was integrated into the pre-existed rock mass rating system such as the geological strength index (GSI). The third article Estimation of Fines Generation in Blasting Using Dynamic rock properties and Near-Field PPV Damage Model addresses a simple quantification of fines generation in blast fragmentation. This study proposes an approach to evaluate the size of blast fragmentation based on strain wave propagation theory and dynamic rock properties. The finer blast fragmentation was assumed to be estimated from the crushed zone model (CZM) where the rock is failed by excessive compressive stress. The volume of fines generation under the four different scenarios by rock and explosive types were calculated based on the Split Hopkinson Pressure Bar (SHPB) experiment and the proposed Near-Field PPV model. This case study indicated that the dynamic PPV model can provide a rough estimate of fines generation for given dynamic rock properties and blast design parameters. The fine prediction using the PPV model would be practical in that it uses PPV, the most common measure at the mining site. The fourth article Tailings Storage Facilities (TSFs) Dust Control Using Biocompatible Polymers describes technological innovation that contributes to sustainability in the environmental sector. This study examined the effectiveness of biocompatible polymers as a dust suppressant on various sources in upstream-type TSF of an open-pit copper mine. From a laboratory wind tunnel to field-scale blowing test, three different scales of experiment observed that the amount of dust generation when applying the polymer has been significantly reduced. The results found that the biocompatible polymer reduces up to 90% of dust generation and reduces the volume of desiccation cracks significantly.