Introduction: Diesel fuel (D) is used in a variety of applications for several industries, including transportation, agriculture, railroads, construction, and mining. In addition to being non-renewable, combustion of diesel fuel (D) leads to negative occupational health outcomes in mining. Currently the Mine Safety and Health Administration (MSHA) regulates diesel exhaust exposure with an 8-hour, time-weighted average permissible exposure limit (PEL) of 160 µg/m3 respirable (<1.0 µm in size) diesel particulate matter (rDPM). Alternative fuels such as biodiesel (B) and a natural gas/diesel blend (GDiesel® [G]) are considered promising alternatives. While the former fuel has been extensively investigated, the latter has not. Objectives: The aims of this dissertation were: (1) to evaluate and compare D and G exhaust exposures from operation of a Wagner and a (2) JCI load-haul-dump (LHD) at the University of Arizona San Xavier Underground Mining Laboratory (SX); and (3) to synthesize existing peer-reviewed literature comparing D emission exposures to those of B and/or G. Methods: For Aims 1 and 2, operator-location and area exposure samples were collected for 200 minutes in an underground mining laboratory while an LHD with oxidation catalyst was operated with D and then G fuel. Analytes of interest included total diesel particulate matter (tDPM) and rDPM, total and respirable elemental and organic carbon (tEC, rEC, tOC, rOC, respectively), as well as the carbonyl compound (CC) formaldehyde (CH2O), nitric oxide (NO), and nitrogen dioxide (NO2). Exposure assessment was conducted within the guidelines of the National Institute of Occupational Safety and Health’s (NIOSH) Manual of Analytical Methods. Specifically, methods #5040 (tDPM, tEC, tOC, rDPM, rEC, rOC), #6014 (NO, NO2), and #2016 (CH2O). Reported laboratory results were time-weighted over an 8-hour period. Between-fuel comparisons were performed using Wilcoxon rank sum testing. Results: For Aim 1, twenty-three D and 12 G samples were collected. Use of G in the Wagner LHD showed statistically and practically significant reductions in rDPM, tDPM, elemental and organic carbons, NO, NO2, and CH2O. For Aim 2, twenty D and 16 G samples were collected. Use of G in the JCI LHD was associated with a significant decrease in NO2 (p=0.012), and significant increase in rEC (p=0.024). After removing outliers, tEC also showed significant increase (p=0.023). Most of the 20 scholarly works reviewed utilized a laboratory setting (75%), while just 15% were conducted in the field, and 10% simulated field conditions. Twenty percent (4) of studies specifically focused on the mining industry. In addition, most evaluated soy-based B (56%) but did not utilize pollution controls (70%) on equipment. Generally, literature showed that use of B decreased DPM and increased oxides of nitrogen (NOx) emission exposures. While more studies (5) showed increases in CCs, two showed decreases. Discussion: Our studies show that: 1) the use of G has potential for statistically and practically significant reductions in several D exhaust contaminants regulated by MSHA; and 2) variability in exposure and emission concentrations across engine, pollution control and operation configurations exists for B and likely exists for G. Differences observed across fuels and studies are also likely due to fuel composition and characteristics, and combustion temperatures. Further occupational health research is needed to evaluate G emissions under controlled conditions with various equipment configurations, as well as in-field settings to determine whether G exhaust exposures are reduced and actually less toxic than those of D. The impact of this work is substantial and timely. Recent increases in respiratory disease prevalence among miners, including young miners, concerns occupational health and industrial hygiene professionals. In addition, MSHA has requested information regarding diesel exhaust controls and is considering future revisions to the rDPM standard. Efforts to reduce D exhaust emissions will also impact occupational and environmental health worldwide.

Traditionally, ventilation requirements for modern, mechanized underground mines have been based upon the power of the diesel equipment fleet, with a multiplier (determined from empirical data collected and compiled over a long period of time or required by regulations) being applied in order to determine the total airflow volume requirements of entire mines and/or individual sections or working areas. Often, in the absence of unusual geographic, climatic or geologic conditions that warranted special consideration, the airflow required for the dilution of diesel exhaust products would provide sufficient ventilation for the entire mine. However, recent studies regarding the health-effects of diesel exhaust, particularly the relationship between exposure to diesel emissions and cancer in humans, coupled with additional scrutiny on so called greenhouse gas emissions, have resulted changes to the regulations for engine and equipment manufacturers to provide cleaner burning and less polluting equipment; and are currently causing profound uncertainty in the mining industry. This influence is particularly felt in the case of ventilation engineers and those involved in long-term mine planning who have responsibility for designing the ventilation systems of both existing and future mining projects around the world. This thesis identifies the major parameters affecting airflow requirements for diesel-powered mining equipment and examines how each of them will change in scale and scope in the aftermath of regulatory changes mandating drastic reductions in the type and amount of diesel engine emissions. Culminating from this research, a new procedure for making total airflow determinations based on the underground diesel equipment fleet is proposed and tested with a practical case-study. Ultimately, the determination of the amount of airflow required for an underground mining operation or other sub-surface facility can depend on several factors, including the equipment fleet, ambient temperature, rock type, mining method and airway type (or use). Obtaining a universal, repeatable protocol for determining airflow quantities required for underground diesel equipment fleets is in the best interest of the industry as a whole, including ventilation practitioners, mine-planning engineers, mining financiers, executives, equipment manufacturers, and of course, the mine workers themselves, who perhaps have the most at stake of anyone involved in the equation. / Thesis (Master, Mining Engineering) -- Queen's University, 2013-05-23 22:33:11.36

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Currently, deficient ventilation systems are a frequently observed problem in mining. Such deficient ventilation systems lead to the recirculation of stale air or air with toxic gases. This translates into an increase in the costs of ventilation and electrical consumption for the mining organizations as conventional and practical solutions simply include options such as buying a greater number of fans. Moreover, this problem also exposes the mine workers to an unsafe work environment with unfavorable conditions that could end in minor, incapacitating, or fatal accidents. Therefore, this research seeks to optimize ventilation systems by introducing the Ventsim software tool to develop efficient coverage, addressing, flow, circuit or network characterization, and air balancing in conjunction with avoiding the stagnation of toxic gases in underground work. The primary result of the proposed model’s application in this study was the reduction in ventilation costs related to electricity consumption.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / The current study is based on a multiple linear regression analysis with an objective to formulate an equation related to the productivity analysis of LHD equipment using independent variables such as the effective utilization of the equipment. To identify the independent variables, main productive factors, such as the actual capacity of the buckets, the transport cycles in the cleaning process, and the performance by means of curves, were analyzed. Comparisons of a Peruvian underground mine case study exhibited that the battery-powered equipment denoted similar production efficiencies to that exhibited by its diesel counterparts; however, the three-tier approach observed that the battery-powered equipment could achieve production efficiencies that are up to 13.8% more as compared to that achieved using its diesel counterparts because of increased effective utilization that can be attributed to long MTBF. The results of this study exhibit that LHDs under battery-powered storage are feasible for underground mining not only because of the fact that they do not emit any polluting gases, which helps to mitigate pollution, but also because of their good production performance that can be considered to be an important pillar in deep mining. Copyright 2019.

Devido ao esgotamento de jazidas economicamente lavráveis a céu aberto, migrou-se para a lavra subterrânea. Porém, como isso é uma prática antiga, alguns métodos de lavra subterrânea deixaram de ser economicamente viáveis devido ao aprofundamento da lavra. Um exemplo disso é a lavra de carvão no sul do Brasil, onde jazidas exploradas a céu aberto ou mesmo pelo método de Câmaras e Pilares, começam a vislumbrar seu exaurimento técnico de lavra, por altos custos e baixa produtividade, o que norteia a busca por alternativas econômicas mais lucrativas. Uma destas alternativas é o método Longwall, praticamente desconhecido no Brasil, porém com crescente e não nova intenção de implementação no país. Isso já se refletiu em tentativas de operações e em novos estudos conceituais de viabilidade para o estado do Rio Grande do Sul. Estes fatores justificaram este estudo que teve por objetivo lançar luz sobre a lavra de carvão pelo método de Longwall, de modo a respaldar a sua implementação no Brasil. Sendo assim, o método foi descrito com enfoque em seus principais pontos, tais como, geomecânica e planejamento; além de apresentar estudos conceituais de lavra em dois cenários. O primeiro projeto conceitual apresenta um cenário tradicional objetivando implementação no Rio Grande do Sul; o segundo, tem por objetivo apresentar relativa flexibilidade do método, adaptando-o a um cenário não tradicional. Concluiu-se com este trabalho que fatores como geomecânica e correto planejamento de lavra são imprescindíveis para o sucesso da implementação do método. A partir dos resultados do estudo conceitual I e da versatilidade proposta no estudo II se justifica o aprofundamento nos estudos de operações por Longwall no país. / Due to the exhaustion of economically mining deposits, migrated to the underground mining. However, as this is an ancient practice, some underground mining methods are no longer economically viable due to the deepening of the mining. An example of this is the mining of coal in southern Brazil, where deposits exploited opencast or even by the Room and Pillars, begin to envision your fatigue, mining technical high costs and low productivity, which guides the search for more profitable economic alternatives. One of these alternatives is the Longwall method, virtually unknown in Brazil, but with growing and not new intention of implementation in the country. It already was reflected in attempts to operations and on new conceptual studies of feasibility for the state of Rio Grande do Sul. These factors justify this study that aimed to shed light on the mining of coal by Longwall method, in order to support its implementation in Brazil. Therefore, the method has been described with focus on its key points, such as, geomechanics and planning; In addition to presenting conceptual studies of raging in two scenarios. The first conceptual design features a traditional setting with the objective of implementation in the Rio Grande do Sul; the second aims to introduce on the flexibility method, adapting it to a non-traditional setting. This work concluded that factors like geomechanics and correct planning of mining are indispensable for the successful implementation of the method. From the results of the study and conceptual versatility proposal in study II justification the deepening in the studies of Longwall operations in the country.

Research shows miners can be exposed to foot-transmitted vibration (FTV) when operating various pieces of underground mining equipment, and case reports suggest workers are experiencing symptoms similar to those of hand-arm vibration syndrome in their feet. A field study was conducted to measure and document FTV exposure associated with operating underground mining equipment, and probable health risks were determined based on both ISO 2631-1 (1997) for WBV and ISO 5349-1 (2004) for HAV. Seventeen participating operator’s also reported musculoskeletal discomfort. Seventeen male participants ranging between 24-61 years of age, with an average height and mass of 175.0cm and 88.2kg volunteered for the study. Seventeen pieces of equipment were tested; 1 locomotive, 1 crusher, 9 bolter drills (4 scissor platforms, 2 Maclean, 2 Boart/basket, and 1 RDH), and 6 jumbo drills. Including all seventeen pieces of underground mining equipment, the vibration acceleration ranged from 0.13-1.35m/s2 with dominant frequencies between 1.25-250Hz according to ISO 2631-1. According to ISO 5349-1 vibration acceleration ranged from 0.14-3.61m/s2 with dominant frequencies between 6.3-250Hz. Furthermore, the magnitude of FTV measured on the jumbo drills with grated platforms (#5 and #6) was less than FTV measured from the jumbo drills with, solid metal surfaces. Additionally, twelve of the seventeen equipment operators indicated a complaint of discomfort in their lower body (specifically at the level of the knee or lower). The health risk analysis based on ISO 2631-1 indicated that one operator (bolter drill #9) was exposed to vibration above the criterion value, while the health risk analysis based on ISO 5349-1 indicated iv that two operators (jumbo drill #1 and bolter drill #1) were exposed to vibration above the criterion value. Operators reported very severe or severe discomfort; however, the same operators were not the operators of the equipment with FTV exposure levels above the ISO standards, leaving evidence to suggest that the standards are not properly assessing injury risk to vibration exposure via the feet. Future research is needed to develop a standard specific for FTV and to determine the link between early musculoskeletal injury reporting and the onset of vibration white foot. To do so, a better understanding of the biodynamic response of the foot to FTV is needed. A laboratory study was conducted to 1) measure and document transmissibility of FTV from (a) floor-to-ankle (lateral malleolus), and (b) floor-to-metatarsal, during exposure to six levels of vibration (25Hz, 30Hz, 35Hz, 40Hz, 45Hz, and 50Hz) while standing, and 2) to determine whether independent variables (vibration exposure frequency, mass, arch type) influence transmissibility (dependent variable) through the foot. A two-way repeated measures analysis of variance (ANOVA) was conducted. There was a significant interaction between transmissibility location and exposure frequency (λ = 0.246, F (5,25) = 15.365, p = 0.0001). There were significant differences in mean transmissibility between the ankle and metatarsal at 40Hz [t(29) = 4.116, p = 0.00029], 45Hz [t(29) = 6.599, p = 0.00000031], and 50Hz [t(29) = 8.828, p = 0.000000001]. The greatest transmissibility at the metatarsal occurred at 50Hz and at the ankle (lateral malleolus) transmissibility was highest from 25-30Hz, indicating the formation of a local resonance at each location. v Future research should focus on identifying resonance frequencies at different locations on the feet. This information is needed to develop an exposure guideline to help protect workers from exposure to FTV, and to develop personal protective equipment capable of attenuating harmful FTV exposure frequencies.

Devido ao esgotamento de jazidas economicamente lavráveis a céu aberto, migrou-se para a lavra subterrânea. Porém, como isso é uma prática antiga, alguns métodos de lavra subterrânea deixaram de ser economicamente viáveis devido ao aprofundamento da lavra. Um exemplo disso é a lavra de carvão no sul do Brasil, onde jazidas exploradas a céu aberto ou mesmo pelo método de Câmaras e Pilares, começam a vislumbrar seu exaurimento técnico de lavra, por altos custos e baixa produtividade, o que norteia a busca por alternativas econômicas mais lucrativas. Uma destas alternativas é o método Longwall, praticamente desconhecido no Brasil, porém com crescente e não nova intenção de implementação no país. Isso já se refletiu em tentativas de operações e em novos estudos conceituais de viabilidade para o estado do Rio Grande do Sul. Estes fatores justificaram este estudo que teve por objetivo lançar luz sobre a lavra de carvão pelo método de Longwall, de modo a respaldar a sua implementação no Brasil. Sendo assim, o método foi descrito com enfoque em seus principais pontos, tais como, geomecânica e planejamento; além de apresentar estudos conceituais de lavra em dois cenários. O primeiro projeto conceitual apresenta um cenário tradicional objetivando implementação no Rio Grande do Sul; o segundo, tem por objetivo apresentar relativa flexibilidade do método, adaptando-o a um cenário não tradicional. Concluiu-se com este trabalho que fatores como geomecânica e correto planejamento de lavra são imprescindíveis para o sucesso da implementação do método. A partir dos resultados do estudo conceitual I e da versatilidade proposta no estudo II se justifica o aprofundamento nos estudos de operações por Longwall no país. / Due to the exhaustion of economically mining deposits, migrated to the underground mining. However, as this is an ancient practice, some underground mining methods are no longer economically viable due to the deepening of the mining. An example of this is the mining of coal in southern Brazil, where deposits exploited opencast or even by the Room and Pillars, begin to envision your fatigue, mining technical high costs and low productivity, which guides the search for more profitable economic alternatives. One of these alternatives is the Longwall method, virtually unknown in Brazil, but with growing and not new intention of implementation in the country. It already was reflected in attempts to operations and on new conceptual studies of feasibility for the state of Rio Grande do Sul. These factors justify this study that aimed to shed light on the mining of coal by Longwall method, in order to support its implementation in Brazil. Therefore, the method has been described with focus on its key points, such as, geomechanics and planning; In addition to presenting conceptual studies of raging in two scenarios. The first conceptual design features a traditional setting with the objective of implementation in the Rio Grande do Sul; the second aims to introduce on the flexibility method, adapting it to a non-traditional setting. This work concluded that factors like geomechanics and correct planning of mining are indispensable for the successful implementation of the method. From the results of the study and conceptual versatility proposal in study II justification the deepening in the studies of Longwall operations in the country.

Devido ao esgotamento de jazidas economicamente lavráveis a céu aberto, migrou-se para a lavra subterrânea. Porém, como isso é uma prática antiga, alguns métodos de lavra subterrânea deixaram de ser economicamente viáveis devido ao aprofundamento da lavra. Um exemplo disso é a lavra de carvão no sul do Brasil, onde jazidas exploradas a céu aberto ou mesmo pelo método de Câmaras e Pilares, começam a vislumbrar seu exaurimento técnico de lavra, por altos custos e baixa produtividade, o que norteia a busca por alternativas econômicas mais lucrativas. Uma destas alternativas é o método Longwall, praticamente desconhecido no Brasil, porém com crescente e não nova intenção de implementação no país. Isso já se refletiu em tentativas de operações e em novos estudos conceituais de viabilidade para o estado do Rio Grande do Sul. Estes fatores justificaram este estudo que teve por objetivo lançar luz sobre a lavra de carvão pelo método de Longwall, de modo a respaldar a sua implementação no Brasil. Sendo assim, o método foi descrito com enfoque em seus principais pontos, tais como, geomecânica e planejamento; além de apresentar estudos conceituais de lavra em dois cenários. O primeiro projeto conceitual apresenta um cenário tradicional objetivando implementação no Rio Grande do Sul; o segundo, tem por objetivo apresentar relativa flexibilidade do método, adaptando-o a um cenário não tradicional. Concluiu-se com este trabalho que fatores como geomecânica e correto planejamento de lavra são imprescindíveis para o sucesso da implementação do método. A partir dos resultados do estudo conceitual I e da versatilidade proposta no estudo II se justifica o aprofundamento nos estudos de operações por Longwall no país. / Due to the exhaustion of economically mining deposits, migrated to the underground mining. However, as this is an ancient practice, some underground mining methods are no longer economically viable due to the deepening of the mining. An example of this is the mining of coal in southern Brazil, where deposits exploited opencast or even by the Room and Pillars, begin to envision your fatigue, mining technical high costs and low productivity, which guides the search for more profitable economic alternatives. One of these alternatives is the Longwall method, virtually unknown in Brazil, but with growing and not new intention of implementation in the country. It already was reflected in attempts to operations and on new conceptual studies of feasibility for the state of Rio Grande do Sul. These factors justify this study that aimed to shed light on the mining of coal by Longwall method, in order to support its implementation in Brazil. Therefore, the method has been described with focus on its key points, such as, geomechanics and planning; In addition to presenting conceptual studies of raging in two scenarios. The first conceptual design features a traditional setting with the objective of implementation in the Rio Grande do Sul; the second aims to introduce on the flexibility method, adapting it to a non-traditional setting. This work concluded that factors like geomechanics and correct planning of mining are indispensable for the successful implementation of the method. From the results of the study and conceptual versatility proposal in study II justification the deepening in the studies of Longwall operations in the country.

M.A. / Believing in misfortune is sometimes considered regarded as barbaric and superstitious. Regardless of how these practices are perceived, people strongly believe in the existence of misfortune and bad luck. The occurrence of misfortune is often attributed to a wide range of sources, such as ancestors, river people, pollution and witches. Together the river people, the ancestors, pollution and witchcraft provide an explanation for evil and misfortune. Misfortune can therefore arise from one, or a combination of these four, or additionally from natural, and/or non-natural means. Misfortune is not only an interesting concept but also problematic to those who believe in it. Misfortune can become a self-fulfilling prophecy. In other words it becomes real in their lives and it directly influences them. Preventive strategies for evil and misfortune are as different as the causes. The kinds of experiences of misfortune that are taken as data are bodily conditions, failures and losses. A qualitative study was conducted at Harmony Gold’s Doornkop Shaft near Soweto and Sir Albert Medical Centre a nearby situated medical facility for specifically mine related injuries and health issues in Randfontein, to determine how mineworkers perceive and experience misfortune and if they do, how they explain it and deal with it? The target population was underground mineworkers because according to Xhosa custom (isithethe) one is prohibited from working underground because it is a sacred place of the dead. Whenever therefore they go down, that symbolises death and in some cases they would be regarded as people who are shaking the bones of ancestors. Working underground therefore makes one prone to accidents, illness and misfortune. The project also examines the rituals of migrants which serve as a form of preventing misfortune and ensuring good health. It is argued that working underground is a violent experience. The miners struggle with the environment, heat, falling of rocks, unnatural conditions and bad air. However, this project points out the importance of solidarity among underground workers more especially during accidents where they become a source of inspiration to one another and rescue each other before the emergency services reach them. / Prof. Anton Senekal

This work focuses on the operational and safety issues associated with karst voids in large opening underground mines. Issues include water inrush, structural instability, and engineering uncertainty in these environments. Coupled with the fracturing prevalent in folded sedimentary rocks, karsts are complex and challenging ground control risks. Traditional methods of predicting karst void locations such as probe-drilling are impeded by the inconsistent spatial distribution and variable sizes of the features. Ground penetrating radar (GPR) is a geophysical technique that transmits radio waves into a medium and subsequently detects reflected waves via a receiver. The travel time and energy of received signals are then processed and interpreted. The difference in material properties between limestone and open karst voids causes strong reflections. This work summarizes a series of 2D and 3D GPR surveys for karst void mapping within a mine pillar and within sill pillars between mine levels in a large opening underground limestone mine. In this case study mine, karst voids are hazardous ground control risks that interact with geologic discontinuities, creating free blocks within the rock mass. As tunnels are advanced via blasting, unknown karst voids may be exposed and pose risks to mining personnel. The karst voids also form a hydrogeological network of water reservoirs with spatial locations throughout the rock mass that are difficult to predict with traditional methods such as drilling. While GPR has been utilized throughout several industries for anomaly detection, mapping, and validating other geophysical data sets, this technique has not seen the same proliferation within the mining industry. Regarding published literature, there is a lack of works that detail the applicability of GPR in underground mining scenarios. The aim of this work is to expand on previous methodologies establishing GPR as a useful tool in underground mining applications, and to discuss the benefits and limitations GPR data in such scenarios. / Master of Science / This work focuses on the operational and safety issues associated with karst voids in large opening underground mines. Typical issues include water flooding into the tunnels and rocks falling out from the roof and walls, among other things. Sedimentary rock structures sometimes are geologically complex, and karst voids only add to that complexity. Engineers usually predict karst void locations with drilling or statistics, but this is often challenging as karst voids have various shapes and orientations. Ground penetrating radar (GPR) is a geophysical technique that sends electric signals into the rock; these signals can reflect off of karst voids and other anomalies. The travel time and energy of signals that come back to the antennas are then processed and interpreted. The difference in material properties between limestone and open karst voids causes strong reflections. This work shows a series of 2D and 3D GPR surveys for karst void mapping within a pillar in a stone mine and also below the floor of mine tunnels. In this mine, karst voids are very dangerous and the miners spend significant time and resources to ensure the tunnels walls are stable. As tunnels are blasted, hidden karst voids may be exposed and pose unpredicted risks to miners. The karst voids are also connected by cracks and discontinuities, providing a path for water to travel along. While GPR has been used in various ways among the construction, civil engineering, and tunneling industries, there is not enough literature pertaining to its benefits for mines. The goal of this work is to grow the available literature on GPR in mining and to talk about the best practices for GPR use as a means of improving health and safety for miners underground.