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Optimal production rates in opencast coal mining : a value driven approachDe Jongh, Iwan 26 June 2012 (has links)
From small exploration companies to multi-national mining houses all at some point in the project lifetime embark on evaluation studies where the most value-generating method of extracting the ore is investigated. Early phases in exploration projects will have the need for an order-of-magnitude estimation as to the scale of the potential operation, and advanced projects will have detailed mine and financial plans to guide them to execution. In both instances this thesis provides a method of optimising the mining rate to deliver the highest possible value to the mining company whilst considering the possible risks from changes in the market. This can be compared to the value the country gains from the exploitation of its natural resources to find a mutually beneficial solution. Copyright / Dissertation (MSc)--University of Pretoria, 2012. / Geology / unrestricted
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Characterisation of airborne dust in South African underground and opencast coal mines : a pilot study / Machiel Jacobus WentzelWentzel, Machiel Jacobus January 2015 (has links)
Dust is a well-known occupational hygiene challenge and has been throughout the years, especially in the coal mining industry. The hazards arising from coal dust will differ between geographical areas due to the unique characteristics of dust from the coal mining environment. It is therefore of upmost importance to identify these qualities or characteristics of coal dust in order to understand the potential hazards it may pose. It is also important to consider the presence of nanoparticles which until recently remained neglected due to the absence of methods to study them.
Aim: The aim of this study was to collect significant quantities of airborne dust through static sampling to characterise the physical, morphological as well as elemental properties of inhalable and respirable dust produced at two South African underground and two opencast coal mines. Personal exposure quantification was therefore not the primary concern in this study. Method: Static dust sampling was done at two mining areas of the two opencast and underground coal mines using four Institute of Occupational Medicine (IOM) and four cyclone samplers per area at each mine. A condensation particle counter (CPC) was also used at the opencast areas. The opencast areas included blast hole drilling, drag line and power shovel operations. The underground areas included the continuous miner and roof bolter operations. Gravimetric analyses of the cyclone and IOM samples were done as well as scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis. Results: Mine A (opencast and underground) produces higher grade coal in comparison to mine B (opencast and underground). Gravimetric analysis indicated higher average inhalable (55.35 mg/m3) and respirable (2.13 mg/m3) concentrations of dust in the underground areas when compared to the opencast areas (34.73 mg/m3 and 0.33 mg/m3). Blast hole drilling operations indicated higher average inhalable and respirable dust concentrations (39.02 mg/m3 and 0.41 mg/m3) when compared to the drag line and power shovel operations (30.44 mg/m3 and 0.246 mg/m3). CPC results showed higher average concentrations of sub-micron particles at the blast hole drilling areas per cubic metre (63132 x 106) compared to the drag line and power shovel operations (38877 x 106). EDS analysis from the opencast areas indicated much higher concentrations of impurities (with lower concentrations of carbon – 33.33%) when compared to samples taken from the underground mining activities (65.41%). The EDS results from the opencast areas differed substantially. The highest concentrations of silica were found at the blast hole drilling areas. EDS results from the underground areas indicated that mine A has slightly higher concentrations of carbon (66.2%) with less impurities when compared to mine B (64.62%). The continuous miner operations showed a higher concentration of impurities when compared to the dust
from the roof bolter. SEM results from the opencast areas revealed that the majority of particles are irregularly shaped and the presence of quartz and agglomerations are evident. SEM results from the underground areas were similar except that the roof bolter produced smaller sized particles when compared to the continuous miner. It also seemed that the areas with higher levels of impurities produced more sub-micron particles. Conclusions: It is possible to identify the majority of physical and elemental characteristics of coal dust by means of gravimetric analysis, particle counting, SEM and EDS. There were differences found, regarding the morphological; chemical and physical characteristics, between the different opencast and underground areas at mine A and mine B due to the type of mining activity and amount of overburden present. Silicosis, Pneumoconiosis and Chronic obstructive pulmonary disease are some of the possible health concerns. It has been seen that dust from higher grade coal mines contributed to more developed stages of these diseases. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2015
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Characterisation of airborne dust in South African underground and opencast coal mines : a pilot study / Machiel Jacobus WentzelWentzel, Machiel Jacobus January 2015 (has links)
Dust is a well-known occupational hygiene challenge and has been throughout the years, especially in the coal mining industry. The hazards arising from coal dust will differ between geographical areas due to the unique characteristics of dust from the coal mining environment. It is therefore of upmost importance to identify these qualities or characteristics of coal dust in order to understand the potential hazards it may pose. It is also important to consider the presence of nanoparticles which until recently remained neglected due to the absence of methods to study them.
Aim: The aim of this study was to collect significant quantities of airborne dust through static sampling to characterise the physical, morphological as well as elemental properties of inhalable and respirable dust produced at two South African underground and two opencast coal mines. Personal exposure quantification was therefore not the primary concern in this study. Method: Static dust sampling was done at two mining areas of the two opencast and underground coal mines using four Institute of Occupational Medicine (IOM) and four cyclone samplers per area at each mine. A condensation particle counter (CPC) was also used at the opencast areas. The opencast areas included blast hole drilling, drag line and power shovel operations. The underground areas included the continuous miner and roof bolter operations. Gravimetric analyses of the cyclone and IOM samples were done as well as scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis. Results: Mine A (opencast and underground) produces higher grade coal in comparison to mine B (opencast and underground). Gravimetric analysis indicated higher average inhalable (55.35 mg/m3) and respirable (2.13 mg/m3) concentrations of dust in the underground areas when compared to the opencast areas (34.73 mg/m3 and 0.33 mg/m3). Blast hole drilling operations indicated higher average inhalable and respirable dust concentrations (39.02 mg/m3 and 0.41 mg/m3) when compared to the drag line and power shovel operations (30.44 mg/m3 and 0.246 mg/m3). CPC results showed higher average concentrations of sub-micron particles at the blast hole drilling areas per cubic metre (63132 x 106) compared to the drag line and power shovel operations (38877 x 106). EDS analysis from the opencast areas indicated much higher concentrations of impurities (with lower concentrations of carbon – 33.33%) when compared to samples taken from the underground mining activities (65.41%). The EDS results from the opencast areas differed substantially. The highest concentrations of silica were found at the blast hole drilling areas. EDS results from the underground areas indicated that mine A has slightly higher concentrations of carbon (66.2%) with less impurities when compared to mine B (64.62%). The continuous miner operations showed a higher concentration of impurities when compared to the dust
from the roof bolter. SEM results from the opencast areas revealed that the majority of particles are irregularly shaped and the presence of quartz and agglomerations are evident. SEM results from the underground areas were similar except that the roof bolter produced smaller sized particles when compared to the continuous miner. It also seemed that the areas with higher levels of impurities produced more sub-micron particles. Conclusions: It is possible to identify the majority of physical and elemental characteristics of coal dust by means of gravimetric analysis, particle counting, SEM and EDS. There were differences found, regarding the morphological; chemical and physical characteristics, between the different opencast and underground areas at mine A and mine B due to the type of mining activity and amount of overburden present. Silicosis, Pneumoconiosis and Chronic obstructive pulmonary disease are some of the possible health concerns. It has been seen that dust from higher grade coal mines contributed to more developed stages of these diseases. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2015
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Exposure of earth moving equipment operators to vibration and noise at an opencast coal mine / Mandi GroenewaldGroenewald, Mandi January 2013 (has links)
The phrase “miner” is comparatively non-specific as mining is seen as a multi-disciplinary industry that includes several diverse professions and trades (Donoghue, 2004). One of the functions within mining is the operation of earth moving equipment (EME) such as haul trucks, dozers, excavators and graders. EME are generally used to shift large amounts of earth, dig foundations and landscape areas.
In this study whole-body vibration (WBV) and noise exposure of earth moving equipment (EME) operators were assessed, at an opencast coalmine in South Africa. The aim was to evaluate and quantify the levels of exposure in different EME types, as well as to compare old with new EME, in order to estimate if machine hours contribute to higher noise and vibration levels. WBV and noise levels of the Production and Rehabilitation operations were compared, to determine whether different activities led to different exposures.
Internationally accepted standardised methods, ISO 2631-1 for WBV and SANS 10083:2012 for noise were followed and correctly calibrated instrumentation was used. WBV measurements were conducted with a tri-axial seat pad accelerometer (SVAN 958) and personal noise dosimeters (Casella 35 X) were used for noise measurements. Measurements were taken over a period of four months.
With regards to the European Union (EU) limit (1.15 m/s2) and the EU action limit (0.5 m/s2) it was noted that operators of EME within the Production operation were not exposed to WBV levels above the EU limit, but 77% of these operators were exposed to WBV levels above the EU action limit. It was also evident that 45% of operators’ vibration exposure levels were within the Health Guidance Caution Zone (HGCZ) of 0.45 – 0.90 m/s2. Within the Rehabilitation operation, 9% of operators were exposed to WBV levels above the EU limit and 55% above the EU action limit. Furthermore 50% was within the HGCZ. With regards to the noise Occupational exposure limit (OEL) of 85 dB(A) as stated by the Mine Health and Safety Regulations (MHSR) it was noted that 27% of operators within the Production operation were exposed to noise levels above the limit and for operators within the Rehabilitation operation 14% were reported to be exposed at or above the limit. Statistically significant difference in noise exposure was found between the Production operation and Rehabilitation operation. Results indicated that the majority of EME operators were exposed to high noise levels, in some cases exceeding the 85 dB(A) OEL. A significant positive correlation was found between noise exposure levels and machine hours. Thus higher noise levels were observed as machine operating hours increased.
It was found that operators were exposed predominantly to vibration and noise levels below the limits. However the Dozer group within the Production and Rehabilitation operations in some cases exceeded the vibration and noise legal limit. High exposure levels within the Dozer group can be attributed to the fact that these EME types mostly perform activities in uneven areas and the tracks on which these Dozers move also contribute to higher vibration levels due to a lack of a suspension. Controls should be implemented as far as is reasonably practicable to ensure that operators are not exposed above recommended or permissible levels for each hazard. Continuous improvement of the maintenance plan for all EME and regularly grading and maintaining travelling ways are some of the controls that will contribute to lower vibration and noise levels. Operators exposed to high noise levels should use hearing protective devices as an early on preventative measure to reduce noise exposure levels. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2014
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Exposure of earth moving equipment operators to vibration and noise at an opencast coal mine / Mandi GroenewaldGroenewald, Mandi January 2013 (has links)
The phrase “miner” is comparatively non-specific as mining is seen as a multi-disciplinary industry that includes several diverse professions and trades (Donoghue, 2004). One of the functions within mining is the operation of earth moving equipment (EME) such as haul trucks, dozers, excavators and graders. EME are generally used to shift large amounts of earth, dig foundations and landscape areas.
In this study whole-body vibration (WBV) and noise exposure of earth moving equipment (EME) operators were assessed, at an opencast coalmine in South Africa. The aim was to evaluate and quantify the levels of exposure in different EME types, as well as to compare old with new EME, in order to estimate if machine hours contribute to higher noise and vibration levels. WBV and noise levels of the Production and Rehabilitation operations were compared, to determine whether different activities led to different exposures.
Internationally accepted standardised methods, ISO 2631-1 for WBV and SANS 10083:2012 for noise were followed and correctly calibrated instrumentation was used. WBV measurements were conducted with a tri-axial seat pad accelerometer (SVAN 958) and personal noise dosimeters (Casella 35 X) were used for noise measurements. Measurements were taken over a period of four months.
With regards to the European Union (EU) limit (1.15 m/s2) and the EU action limit (0.5 m/s2) it was noted that operators of EME within the Production operation were not exposed to WBV levels above the EU limit, but 77% of these operators were exposed to WBV levels above the EU action limit. It was also evident that 45% of operators’ vibration exposure levels were within the Health Guidance Caution Zone (HGCZ) of 0.45 – 0.90 m/s2. Within the Rehabilitation operation, 9% of operators were exposed to WBV levels above the EU limit and 55% above the EU action limit. Furthermore 50% was within the HGCZ. With regards to the noise Occupational exposure limit (OEL) of 85 dB(A) as stated by the Mine Health and Safety Regulations (MHSR) it was noted that 27% of operators within the Production operation were exposed to noise levels above the limit and for operators within the Rehabilitation operation 14% were reported to be exposed at or above the limit. Statistically significant difference in noise exposure was found between the Production operation and Rehabilitation operation. Results indicated that the majority of EME operators were exposed to high noise levels, in some cases exceeding the 85 dB(A) OEL. A significant positive correlation was found between noise exposure levels and machine hours. Thus higher noise levels were observed as machine operating hours increased.
It was found that operators were exposed predominantly to vibration and noise levels below the limits. However the Dozer group within the Production and Rehabilitation operations in some cases exceeded the vibration and noise legal limit. High exposure levels within the Dozer group can be attributed to the fact that these EME types mostly perform activities in uneven areas and the tracks on which these Dozers move also contribute to higher vibration levels due to a lack of a suspension. Controls should be implemented as far as is reasonably practicable to ensure that operators are not exposed above recommended or permissible levels for each hazard. Continuous improvement of the maintenance plan for all EME and regularly grading and maintaining travelling ways are some of the controls that will contribute to lower vibration and noise levels. Operators exposed to high noise levels should use hearing protective devices as an early on preventative measure to reduce noise exposure levels. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2014
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Geokinematische Abläufe bei der Verflüssigung von TagebaukippenWittig, Manfred 28 September 2017 (has links) (PDF)
Auf den Innenkippen nehmen mit dem Anstieg des Grundwassers die Zahl der Verflüssigungsereignisse und auch die Größe der verflüssigten Bereiche zu. Besonders davon betroffen ist der sogenannte Nordraum der Lausitz südlich von Lübbenau. Dort wurden deshalb Böschungskonturen vor und nach den Verflüssigungsereignissen über Jahre systematisch erfasst. Die erfassten Konturen wurden geokinematisch analysiert, um charakteristische Bewegungsmuster erkennen und beschreiben zu können. Das Ergebnis ermöglicht eine neue Klassifizierung der auf Innenkippen auftretenden Verformungsvorgänge. Darauf aufbauend, entstand eine neue Methodik zur Berechnung der Standsicherheit verflüssigungsgefährdeter Innenkippenflächen deren Basis die Theorien des Erddrucks und Hydromechanik sind. Für den Nachweis des horizontalen Gleichgewichts einer Böschung wird ein Kräfte-, für das der vertikalen, ein Momentenvergleich hergeleitet. Mit einem hydromechanischen Ansatz ist es auch möglich, zusätzlich die Endgeometrie der sich nach der Verflüssigung einstellenden Böschung zu berechnen. Die Ergebnisse der Standsicherheitsberechnungen und der geometrischen Endkonturen zeigen überraschende Übereinstimmungen mit den erfassten gegangenen Böschungsbewegungen.
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Markscheiderisch-geotechnisches Monitoring und UAV-Einsätze in geotechnischen Schwerpunktbereichen bei der LEAGSchröder, Cordula, Drechsel, Marco 28 September 2017 (has links) (PDF)
Zur Überwachung geotechnischer Schwerpunktbereiche kommen in den Tagebauen der Lausitz Energie Bergbau AG unterschiedliche Systeme zum Einsatz. Eine hohe Flexibilität und erweitere Einsatzmöglichkeiten ergaben sich durch die Verbindung einfacher GNSS-Empfänger und geotechnischer Sensoren zu einem Gesamtsystem (A07Geo). Darüber hinaus werden A07-Empfänger zur Bewältigung vielfältiger Fragestellungen herangezogen. Zwei im Bestand der Markscheiderei befindliche UAV’s eröffnen die Möglichkeit, bei geotechnischen Ereignissen schnellstmöglich auch georeferenziertes Bild- und Videomaterial sowie daraus resultierend Volumenbestimmungen und weiterführende Messungen zur Verfügung zu stellen.
Daneben werden aktuell geotechnische Einsatzszenarien für eine Wärmebildkamera näher untersucht.
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Případová studie rekultivace území lomu Silvestr na Sokolovsku, aneb cesta z lomu na golf / Case Study reclamation of the quarry Silvestr in the Sokolov, or the path from the quarry to golfBarteková, Petra January 2016 (has links)
This diploma thesis deals with the issue of public participation in deciding activities of reclamation. I chose former quarry Silvester near Dolni Rychnov as my research area. This area was transformed into eighteen-holes golf grounds and wood grounds with sport and relax stuff during reclamation work. This thesis consist of theoretical, methodological and empirical section. Theoretical section introduce basic concept of recultivation, law regulating recultivation, conservation, restoration ecology as scientic field and last but not least Sokolov region as region with long tradition of recultivation. The Methodological part describes methods of practical research, which is essential part of this thesis. The Empirical section introduce results of my research. Key words: reclamation, opencast coal-mining, restauration ekology, nature conservation, reclamation project, expert interview, questionnaire
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Datenunterstützte Prognose der Eigensetzung von Tagebaukippen unter Nutzung der satellitengestützten RadarinterferometrieMerkel, Natalie, John, André, Benndorf, Jörg 06 September 2023 (has links)
Die satellitengestützte Radarinterferometrie liefert Informationen zu vertikalen Bodenbewegungen in hoher raum-zeitlicher Auflösung. Moderne Auswerteverfahren in Kombination mit hochauflösenden Sensoren ermöglichen die Anwendung dieser Monitoringmethode auf Tagebaukippen. Die damit verfügbare Datenbasis erlaubt eine flächenhafte Analyse des Setzungsverhaltens der Oberfläche der Tagebaukippe und erweitert damit die bisherige punktartige Betrachtung unter Nutzung von Höhenfestpunkten. Der vorliegende Beitrag demonstriert, wie aus den räumlich verteilten Zeitreihen eine flächenhafte Modellierung des Zeitsetzungsverhaltens von Tagebaukippen erfolgen kann. Dazu werden klassische Modelle des Zeitsetzungsverlaufes auf die Ergebnisse der satellitengestützten Radarinterferometrie angewandt. Im Ergebnis kann geschlussfolgert werden, dass das hier vorgestellte Verfahren eine nahezu rein datengetriebene Prognose von wichtigen Indikatoren, wie z. B. Zeit bis zum Abklingen der Setzung oder zu erwartende maximale Setzung, erlaubt. Weiterhin liefert das Verfahren eine reiche Datengrundlage zur detaillierten Untersuchung weitere Einflussfaktoren auf das Setzungsverhalten von Tagebaukippen.
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Geokinematische Abläufe bei der Verflüssigung von TagebaukippenWittig, Manfred 28 September 2017 (has links)
Auf den Innenkippen nehmen mit dem Anstieg des Grundwassers die Zahl der Verflüssigungsereignisse und auch die Größe der verflüssigten Bereiche zu. Besonders davon betroffen ist der sogenannte Nordraum der Lausitz südlich von Lübbenau. Dort wurden deshalb Böschungskonturen vor und nach den Verflüssigungsereignissen über Jahre systematisch erfasst. Die erfassten Konturen wurden geokinematisch analysiert, um charakteristische Bewegungsmuster erkennen und beschreiben zu können. Das Ergebnis ermöglicht eine neue Klassifizierung der auf Innenkippen auftretenden Verformungsvorgänge. Darauf aufbauend, entstand eine neue Methodik zur Berechnung der Standsicherheit verflüssigungsgefährdeter Innenkippenflächen deren Basis die Theorien des Erddrucks und Hydromechanik sind. Für den Nachweis des horizontalen Gleichgewichts einer Böschung wird ein Kräfte-, für das der vertikalen, ein Momentenvergleich hergeleitet. Mit einem hydromechanischen Ansatz ist es auch möglich, zusätzlich die Endgeometrie der sich nach der Verflüssigung einstellenden Böschung zu berechnen. Die Ergebnisse der Standsicherheitsberechnungen und der geometrischen Endkonturen zeigen überraschende Übereinstimmungen mit den erfassten gegangenen Böschungsbewegungen.
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