Respirable coal mine dust (RCMD) is one of the biggest occupational health hazards. Dusty mining environments can cause life-threatening respiratory health problems for coal miners known as black lung. Over the last 20 years, the flooded bed dust scrubber (FBS) has been employed as an integral component of dust control strategies for underground continuous mining operations. These units have been shown to be effective and robust in mining environments; however, several technical challenges and knowledge gaps limit their performance and efficiency. Despite the capability of the FBS, there are numerous technical challenges that limit its performance and efficiency. In particular, the static panel filter, instrumental in most scrubber designs, is fundamentally limited in collection efficiency and causes numerous operational challenges including rapid clogging. Furthermore, the current design of the filter panel is not capable of evenly wetting the entire surface area. This allows dust-laden air to pass through the filter media and decreases the cleaning capability of the FBS. In this research, both a lab-scale and a full-scale vibration-enhanced FBS with a liquid-coated filter panel were designed, manufactured, and tested. The results confirmed that a vibration-induced filter panel enhances dust collection performance and reduces mesh clogging. In addition, laboratory-scale mesh clogging tests showed that a hydrophilic mesh provided superior clogging mitigation and better performance. Typical results from bench-scale tests showed notable improvements in dust collection efficiencies by over 6% in wet condition and over 7% in dry condition while reducing mass accumulation in the filter by almost 10% in wet condition and over 40% in dry condition. The prototype testing was less conclusive, with deviations between the static mesh and vibrating mesh depending on the mesh density and operating conditions. Nevertheless, with the highest mesh density tested (30-layer), the vibrating mesh notably outperformed the static mesh with superior collection efficiency and reduced airflow loss. The system was further analyzed to investigate the size-by-size recovery of dust particles to various endpoints in the scrubber, under both vibrating and static conditions. Results show that while a majority of the particles are recovered into the demister sump, nearly a quarter of the dust mass is recovered upstream of the screen. In addition, the data confirm that vibration prompts notable improvements to collection efficiency, particularly in the finest size class (- 2.5 micron). / Doctor of Philosophy / Coal mine dust is an unintended and unavoidable consequence of coal extraction operations that poses significant health and safety risks. The inhalation of small, respirable dust particles can cause incurable lung diseases, including silicosis and coal workers' pneumoconiosis known as black lung. To minimize occupational hazards of underground coal mine dust, the Mine Safety and Health Administration (MSHA) periodically brings legislation to the industry. The recent respirable dust rule mandates reducing the maximum allowable respirable dust concentrations in the mine environment to below 1.5 mg/m3 at the working face and below 0.5 mg/m3 at intake entries. In order to comply with these regulations, modern mining techniques utilize several dust mitigation strategies, and the flooded-bed dust scrubber (FBS) is one such technology used extensively on continuous miners. The conventional static panel filter, instrumental in most scrubber designs, however, is fundamentally limited in collection efficiencies due to a high clogging rate and a tradeoff between mesh density and airflow rate. Moreover, poorly wetted areas allow dust-laden air to pass through the filter media. To overcome these deficiencies, a novel liquid-coated vibrating mesh panel is introduced in this research. A laboratory-scale dust scrubber unit and a full-scale unit with a vibration-enhanced mesh screen panel were manufactured and employed to investigate the efficacy of the concept as compared to that of a static mesh. A series of experimental design studies were employed to determine the effective vibrational parameters, scrubber operational parameters, and the impact of mesh variations on dust collection and clogging mitigation. Optimized results from this research were also evaluated against those of a static mesh to determine performance improvement while investigating the mechanisms controlling dust collection and particle department through the scrubber system. Results from the laboratory study show that vibrating mesh conditions, higher water flow rates, and a hydrophilic mesh screen panel led to an improvement in the cleaning efficiency of the scrubber system. Compared to a static-mesh to FBS, the vibrating-mesh FBS showed a significant reduction in pressure drop across the mesh screen indicating lower air loss through the test duration. Overall, the findings confirm that vibrating mesh conditions have the ability to improve filter clogging issues while maintaining high collection efficiencies which can lead to better and healthier working conditions and prolonged operational time with less frequent maintenance. This research supports further technological advancement in mine dust mitigation technologies.

This licentiate thesis is part of a Ph.D. project entitled “CDU:T43 Different methods for dust control and evaluating dust control on Nordic gravel roads”. The Ph.D. project is financially supported by the Swedish Road Administration (SRA) through the Centre ofResearch and Education in Operation and Maintenance of the Infrastructure (CDU)within the Swedish Network of Excellence – Road Technology (RT). Much of the research described in this thesis has been carried out in collaboration with SRA Construction and Maintenance, which also contributed financially.One of the most significant problems associated with gravel roads is traffic-generateddust which facilitates the deterioration of the road surface and acts as a major source of particulate matter in the air, thus affecting traffic safety, public economics, and environmental quality.This work describes different programs for evaluating the effectiveness of different dust suppressants and the results obtained from completion of these experiments. Inchapter one, a general introduction into this project and its objective will be offered. The next chapter gives insight into the basic concepts of gravel roads. In the third chapter the existing literature concerning dust control of gravel roads is briefly retold. The fourth chapter gives an account of the research methodology. A field evaluation of different dust suppressants will be described in the fifth chapter. Chapter six describes methods for analysing dust suppressant residual concentration of samples taken from the different test road sections included in the above mentioned field evaluation. The objective is to investigate the longevity of these dust suppressants. Results from the analyses of the horizontal diffusion of gravel road generated dust are presented in chapter eight. The ninth chapter offers a description and evaluation of the objective method used for quantitative dust emission measurements by means of a visual method. In chapter tendust emissions are correlated to other general deformation processes on the gravel road.Chapter eleven defines laboratory trials concerning the leaching of dust suppressants from gravel wearing course material when subjected to water. Concentrations of dust suppressant as well as size distribution of gravel material were factors examined in this context. In chapter twelve, laboratory examinations of the drying rate for different combinations of aggregate gradations and chloride compounds will be presented. The thirteenth chapter gives a description of a developed laboratory equipment for evaluatingdust suppressant effectiveness, while chapter fourteen offers a conclusive summary. / QC 20101115

Inhalation of respirable dust in coal mines is a serious occupational health hazard which can lead to the development of chronic and irreversible lung diseases, such as Coal Worker's Pneumoconiosis (CWP) and Progressive Massive fibrosis (PMF). After the passage of the Federal Coal Mine Health and Safety Act (CMHSA) in the late 1960's the prevalence of CWP among US coal miners decreased. However, since the late 1990's a resurgence of lung diseases has been reported, particularly in central Appalachia. On the other hand, dust monitoring data suggest that concentrations of respirable coal mine dust (RCMD) and crystalline silica have been on a downward trend. This contradiction has prompted keen interest in detailed characterization of RCMD to shed light on dust constituents-and their sources. Such information might help miners understand where and under what conditions specific sources contribute to RCMD, and how dust controls and monitoring could be enhanced to mitigate the exposure to respirable hazards. Respirable dust particles generated in coal mines are generally associated with three primary sources: the coal strata that is mined and generates mostly coal particles that could contribute for lung diseases, the rock strata that is cut along with the coal and generates most of the respirable silica and silicates, and the rock dust products that are the main source of carbonates which could produce respiratory irritations. Thermogravimetric Analysis (TGA) is one of many analytical tools that might be used for dust characterization. Its primary benefit is that it can be used to apportion the total sample mass into three mass fractions (i.e., coal, carbonates, non-carbonates) which should be roughly associated with the primary dust sources (i.e., coal strata, rock dust products, rock strata) in many coal mines. This thesis consists of two main chapters: Chapter 1, outlines the research motivation, recaps the efforts to establish a standard TGA method for RCMD, and shows results of the validation experiments that were performed in the current work to enable application of the TGA method to a large set of RCMD and laboratory-generated dust samples. In Chapter 2, 46 lab-generated samples from primary dust source materials collected in 15 coal mines, and 129 respirable dust samples from 23 US coal mines are analyzed using the TGA method validated in Chapter 1. Results for both sets of samples are presented and the mine samples are interpreted based on sampling location, mining method and region. Additionally, Chapter 3 summarizes recommendations for future work. / Master of Science / The chronic exposure to dust generated in underground coal operations represents a serious health concern among coal miners that can lead to the development of lung diseases such as Coal Workers Pneumoconiosis (CWP or "black lung). Despite of dust compliance monitoring data that have shown that the concentrations of dust have been declining, since the late 1990's the number of US coal miners diagnosed with lung diseases has been increasing, especially in central Appalachia. This contradiction has prompted keen interest in detailed characterization of respirable coal mine dust (RCMD) to shed light on dust constituents-and their sources. Such information might help miners understand where and under what conditions specific sources contribute to RCMD, and how dust controls and monitoring could be enhanced to mitigate the exposure to respirable hazards. Thermogravimetric Analysis (TGA) has been proposed as an alternative approach for dust characterization. Its primary benefit is that it can be used to apportion the total sample mass into three mass fractions (i.e., coal, carbonates, non-carbonates) which should be roughly associated with the primary dust sources (i.e., coal strata, rock dust products, rock strata) in many coal mines. This thesis consists of two main chapters: Chapter 1, outlines the research motivation, recaps the efforts to establish a standard TGA method for RCMD, and shows results of the validation experiments that were performed in the current work to enable application of the TGA method to a large set of RCMD and laboratory-generated dust samples. In Chapter 2, 46 lab-generated samples from primary dust source materials collected in 15 coal mines, and 129 respirable dust samples from 23 US coal mines are analyzed using the TGA method validated in Chapter 1. Results for both sets of samples are presented and the mine samples are interpreted based on sampling location, mining method and region. Additionally, Chapter 3 summarizes recommendations for future work.

The purpose of this thesis is to examine the potential of a novel method for analysis and characterization of coal mine dust. Respirable dust has long been an industry concern due to the association of overexposure leading to the development occupational lung disease. Recent trends of increased incidence of occupational lung disease in miners, such as silicosis and Coal Workers Pneumoconiosis, has shown there is a need for a greater understanding of the respirable fraction of dust in underground coal mines. This study will examine the development of a comprehensive standard methodology for characterization of respirable dust via thermogravimetric analysis (TGA). This method was verified with laboratory-generated respirable dust samples analogous to those commonly observed in underground coal mines. Results of this study demonstrate the ability of the novel TGA method to characterize dust efficiently and effectively. Analysis of the dust includes the determination of mass fractions of coal and non-coal, as well as mass fractions of coal, carbonate, and non-carbonate minerals for larger respirable dust samples. Characterization occurs through the removal of dust particulates from the filter and analysis with TGA, which continuously measures change in mass with specific temperature regions associated with chemical changes for specific types of dust particulates. Results obtained from the verification samples reveal that this method can provide powerful information that may help to increase the current understanding of the health risks linked with exposure to certain types of dust, specifically those found in underground coal mines. / Master of Science

In the past several decades there has been an increased interest in sand, dust, and ash particulates ingestion study for gas turbine engine applications. Recently, there has been an increase in commercial and military fleets operating in medium to highly dusty environments, such as areas in Africa, the Middle East, and Asia. Dusty environments can cause blockage in turbine cooling circuits which can lead to early engine maintenance or removals. Ingested debris can melt, forming glassy or molten deposits on various hot section components in gas turbine engines. This thesis evaluates the onset of deposit formation using an experimental rig to perform testing in high temperature environment. In general, deposits on turbine components can affect the operating capacity and the overall operating efficiency of gas turbine engines. Particulate ingestion events can be catastrophic and cost millions of dollars in maintenance and repairs. The experimental work in this thesis focused only on quantifying the initial deposit formation in high temperature environment to aid in the development of resilient engine design and operational diagnostics. Testing was performed using HASTELLOY® X coupons and Arizona Road Dust with main gas flow temperatures between 1050°C and 1100°C. Arizona Road Dust sample with sizing between 2µm and 40µm were used for experimental testing. The sensitivity of the initial deposit formation on cooled HASTELLOY® X coupon surface was investigated by using an inline air heater. Three cooling test conditions: no cooling, 500°C cooling, and 250°C cooling, were used to alter the surface temperature of the coupon during testing. Results from testing indicated cooling test conditions used have a small impact on deposit formation. / Master of Science / In the past several decades there has been an increased interest in sand, dust, and ash particulates ingestion study for gas turbine engine applications. Recently, there has been an increase in commercial and military fleets operating in medium to highly dusty environments, such as areas in Africa, the Middle East, and Asia. Dusty environments can cause blockage in turbine cooling circuits which can lead to early engine maintenance or removals. Ingested debris can melt, forming glassy or molten deposits on various hot section components in gas turbine engines. This thesis evaluates the onset of deposit formation using an experimental rig to perform testing in high temperature environment. In general, deposits on turbine components can affect the operating capacity and the overall operating efficiency of gas turbine engines. Particulate ingestion events can be catastrophic and cost millions of dollars in maintenance and repairs. The experimental work in this thesis focused only on quantifying the initial deposit formation in high temperature environment to aid in the development of resilient engine design and operational diagnostics. Testing was performed using HASTELLOY® X coupons and Arizona Road Dust with main gas flow temperatures between 1050°C and 1100°C. Arizona Road Dust sample with sizing between 2µm and 40µm were used for experimental testing. The sensitivity of the initial deposit formation on cooled HASTELLOY® X coupon surface was investigated by using an inline air heater. Three cooling test conditions: no cooling, 500°C cooling, and 250°C cooling, were used to alter the surface temperature of the coupon during testing. Results from testing indicated cooling test conditions used have a small impact on deposit formation.

Waste generation is a constant activity of daily life, encompassing a wide variety including municipal, hazardous, industrial, agricultural, medical, radioactive, and mining waste, as well as sewage sludge. The purpose of this study is to concentrate on utilizing industrial waste, which adversely affects our environment, for use in engineering construction projects. This aims to evaluate the enhancement in both the soil’s index and engineering properties. In most civil engineering projects, the underlying soils are often unsuitable for construction purposes. Some of these soils experience significant volume changes due to moisture variations, leading to damage and instability of structures and infrastructure built on them. The complete removal and replacement of such high plastic clay and expansive soils is not always a cost-effective solution. Therefore, there's a pressing need to improve their utility by stabilizing them through eco-friendly and sustainable methods.The present research employs five industrial waste materials to enhance the clayey soil available in Carbondale, Illinois. These waste materials include Lime Sludge (LS), Lime Kiln Dust (LKD), Fly Ash (FA), Ground Granulated Blast Furnace Slag (GGBS), and Cement Kiln Dust (CKD). Lime Sludge and Lime Kiln Dust were mixed with the soil at proportions of 2%, 4%, 6%, and 8%. In contrast, Fly Ash and Cement Kiln Dust were used at higher ratios of 8%, 16%, 24%, and 32%. Lastly, Ground Granulated Blast Furnace Slag was added at levels of 5%, 10%, 15%, and 20%, all based on the soil's dry unit weight. The samples were prepared for Unconfined Compression Strength (UCS) and Resilient Modulus (RM) based on the Optimum Moisture Content (OMC) and Maximum Dry Density (MDD) data obtained from miniature Proctor test. These specimens underwent a 14-day curing period, sealed in plastic film and Ziploc bags, and were stored in a controlled water tub at room temperature. The UCS value for the untreated Carbondale soil was 320 kN/m2. The results indicated that with higher content of Lime Kiln Dust (LKD) and Cement Kiln Dust (CKD), the UCS strength tends to increase with CKD exhibiting the most desirable strength characteristics. The UCS value for 8% LKD was 1377.70 kN/m2 i.e., 330.52% increase. While the UCS improvements for 5% GGBS is 51.32% and 6% Lime Sludge (LS) is 51.65% with no significant enhancements, these waste materials can be more effective as modifiers. Furthermore, the study revealed that the optimal quantity of Class F fly ash for soil stabilization is 8% by dry unit weight with UCS value of 486.46 kN/m2 resulting in 52.01% increase in UCS strength, exceeding this percentage might cause reduction in strength. The highest UCS strength was obtained with 24% CKD at 3263.14 kN/m2 which corresponds to 919.70% increase when compared to the untreated soil. The results of the Resilient Modulus (RM or Mr) test indicate that the incorporation of additives to untreated Carbondale soil significantly improved its stiffness characteristics and resistance to different load cycles on the subgrade. However, the soil treated with GGBS showed a decrease in stiffness. The Resilient Modulus values ranged from 2% to 70% for LS, 47% to 128% for LKD, 4% to 35% for FA, 90% to 243% for CKD, and -16% to 0.3% for GGBS for different confining pressures. The regression analysis, using the Uzan (1985) model, showed R² values of 0.910, 0.838, 0.803, 0.871, 0.773, and 0.809 for Carbondale soil, Carbondale soil mixed with 6% LS, 8% LKD, 8% FA, 5% GGBS, and 24% CKD, respectively. These results confirm the reliability of the test, as all samples except the GGBS-treated one have R² values greater than 0.800. Additionally, consolidation tests were conducted to assess the compressibility characteristics of the additives in the soil. The selected samples were those with the mix proportions that yielded the highest UCS strength for each additive. These samples were meticulously prepared based on the moisture-density relationship obtained from the miniature Proctor test and were subjected to loading and unloading in a specific sequence. The results indicated an increase in the Compression Index (Cc) for mixtures with LS, LKD, FA, and CKD. Conversely, the mix containing GGBS displayed a reduction in the Compression Index (Cc). The Carbondale soil stabilized with 6% LS can be used for subbase stabilization as the UCS strength is greater than 345 kPa. Also, 2 to 8% LKD content can be used for subbase and base course stabilization. 8% FA without any activator can be used for subbase stabilizer. GGBS can be used for subbase soil stabilization and finally CKD can be used for both subbase and base course stabilization.

Windblown dust remains a persistent problem within South African urban and peri-urban areas due to the prevailing dry climatic conditions, extensive surface mining and mineral processing. Despite deposition monitoring guidelines and national dust regulations, South Africa still has persistent dust problems in especially gold mining districts. The main aim of the research is to critically evaluate all the potential challenges within dust management which could be responsible for persistent dust problems within gold mining regions of South Africa. The research methodology included a literature review to provide important information regarding the requirements for successful dust management internationally. Data were gathered by using the survey method through questionnaires and interviews as this type of survey method allows for descriptive reporting where respondents provide information on their attitudes and perceptions. In total 37 questionnaires were distributed among two district municipalities, seven gold mining companies, ten interested and affected parties including two non-governmental organizations, as well as five specialists. A total response rate of 81.1 % was achieved. The results of the questionnaires revealed that the most significant challenges to dust management within gold mining regions of South Africa are the following: monitoring networks; monitoring methods; deposition standards; financial provisions; technical skills and capacity; lack of specific dust management plans within air quality management plans; limited regulation and enforcement; limited information and participation of government, lack of participation of interested and affected parties as well as specialists‟ expertise. All the challenges identified were then successfully linked back to the referenced literature from which the challenges were initially derived. The main aim of this research was thus successfully completed by initially identifying the challenges facing dust management within gold mining regions of South Africa and then critically evaluating them and making recommendations. / M. Environmental Management, North-West University, Potchefstroom Campus, 2014

Title from PDF of title page. / Document formatted into pages; contains 48 pages. / Thesis (M.S.P.H.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: International standards establish criteria for size-selective aerosol sampling for industrial hygiene. Commercially available aerosol samplers are designed to conform to these criteria. This study uses semi-monodispersed aerosols generated in a vertically aligned test chamber to compare the performance of three commercially available respirable dust samplers, one of which can, in addition, simultaneously sample for thoracic and inhalable dust fractions. Comparison methods are used to calculate a theoretical fractional value based on the appropriate sampling conventions of the total dust concentration and size distribution of test materials. Performance of actual samplers can be conducted by comparing observed results to the theoretical value. Results show the design of the test chamber and use of fused aluminum oxide is appropriate to conduct simplified performance verification tests for inhalable and respirable dust samplers. / ABSTRACT: This study showed the TSI RespiCon followed the inhalable and respirable conventions closely, but results for the thoracic fraction required the use of a correction factor. The SKC aluminum cyclone tended to undersample the respirable fraction, while the BGI CAS4 cyclone and the TSI RespiCon appear to most closely follow the convention. Improved selection of test material and characterization of particle sizes are recommended to further develop this method of performance verification. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

Windblown dust remains a persistent problem within South African urban and peri-urban areas due to the prevailing dry climatic conditions, extensive surface mining and mineral processing. Despite deposition monitoring guidelines and national dust regulations, South Africa still has persistent dust problems in especially gold mining districts. The main aim of the research is to critically evaluate all the potential challenges within dust management which could be responsible for persistent dust problems within gold mining regions of South Africa. The research methodology included a literature review to provide important information regarding the requirements for successful dust management internationally. Data were gathered by using the survey method through questionnaires and interviews as this type of survey method allows for descriptive reporting where respondents provide information on their attitudes and perceptions. In total 37 questionnaires were distributed among two district municipalities, seven gold mining companies, ten interested and affected parties including two non-governmental organizations, as well as five specialists. A total response rate of 81.1 % was achieved. The results of the questionnaires revealed that the most significant challenges to dust management within gold mining regions of South Africa are the following: monitoring networks; monitoring methods; deposition standards; financial provisions; technical skills and capacity; lack of specific dust management plans within air quality management plans; limited regulation and enforcement; limited information and participation of government, lack of participation of interested and affected parties as well as specialists‟ expertise. All the challenges identified were then successfully linked back to the referenced literature from which the challenges were initially derived. The main aim of this research was thus successfully completed by initially identifying the challenges facing dust management within gold mining regions of South Africa and then critically evaluating them and making recommendations. / M. Environmental Management, North-West University, Potchefstroom Campus, 2014

Call number: LD2668 .T4 1979 C59 / Master of Science