Explosives Engineering Commons^™

Investigating Anisotropic Blast Wave Parameters Near The Explosive-Air Boundary Using Computer Simulation And Experimental Techniques With Varying Charge Geometry, Kelly Williams, Catherine E. Johnson

Mining Engineering Faculty Research & Creative Works

The prediction of blast wave overpressure using scaled distance calculations use the charge mass and radial distance variables and assumes that the blast wave is isotropic. Simulations and empirical studies demonstrate that altering the charge geometry results in a significant deviation in overpressure vs orientation. While this effect has been measured for cylinders, truncated cones, and cubes, the mechanisms driving geometric blast wave product anisotropy have not been well defined. Velocity vectors plotted from computer simulations in this study show an isotropic radial flow from the cylindrical charges, while the prismatic charges with rectangle, triangle, and five-point star cross sections …

Gravity Field Changes During Deep Exploitation Of The Coal Longwall And Their Relation To Stress Distribution And Seismic Activity, Łukasz Kortas

Journal of Sustainable Mining

Mining operations cause volumetric deformations within the rock mass and changes in its density, to which the gravimetric method is sensitive. These changes are particularly well seen in periodic measurements of the local gravity field. The paper analyses the relationship between the movement of a longwall in a coal seam and the change in the distribution of the gravity field in time and space observed on the ground surface. Relative gravimetric measurements were carried out in six series between 2018 and 2020; before the start of coal extraction, with the progress of the longwall and after the cessation of mining. …

Study Of The Relationship Of Tidal Changes In Gravity With The Time Of Mining Tremors In The Area Of The Mining Longwall In A Coal Mine – Case Study In Uscb, Poland, Sławomir Siwek

Journal of Sustainable Mining

Deep mining of coal deposits in Upper Silesia Coal Basin in Poland over several hundred years has led to disturbances in the natural state of equilibrium. As a result of changes in stress distribution, mass distribution (changes in gravity forces) and deformation of the rock mass, seismic tremors with energy reaching up to 10E+09J are generated. In this paper, the time of mining tremors occurrence is linked with changes in the gravitational load of the rock mass caused by litosphere tides, which are considered to be one of the factors leading to occurrence of natural seismic tremors. The analysis used …

Decarbonisation – Origins And Evolution Of The Process On The European Level, Sylwia Jarosławska-Sobór

Journal of Sustainable Mining

Decarbonisation of the european economy is one of the most important megatrends that will shape economic and social development in the coming years. This paper discusses the basic concepts of decarbonisation in terms of climate change, the history of this idea development and the legal basis introduced in the European Union, including key European documents and tools influencing the process, like ETS or CO2 emission allowances. Background on decarbonisation has been presented as a European roadmap to achieve a low-carbon economy in Europe. In the article the main assumptions of the EU strategy papers like Clean Energy for All Europeans …

Determination Of The Stress-Strain State Of Rock Mass And Zone Of Inelastic Deformation Around Underground Mine Excavation Using Modern Methods Of Numerical Modelling, Sergey A. Ignatiev, Aleksandr E. Sudarikov, Askar Zh. Imashev

Journal of Sustainable Mining

The paper reviews methods and trends of numerical modelling of geomechanical processes around underground mine excavations. The most rational method of determining the additional stresses caused by the mine excavations is chosen. Mathematical modelling was performed for excavations of various cross sections and different strength of rocks. The dimensions of the inelastic deformation zone around the mine excavations have been identified. The area of the total fracture zone around the excavation, as well as the area of the roof fracture zone are calculated. The results of the fracture zone modelling are presented both as coordinates and in a graphical form. …

Thin Safety Margin: The Sefor Super-Prompt-Critical Transient Experiments, Ozark Mountains, Arkansas 1970–1971, Jerry Havens, Collis Geren

Arkansas Scholarly Editions

Thin Safety Margin charts the history of SEFOR, a twenty-megawatt reactor that operated for three years in the rural Ozark Mountains of Arkansas as part of an internationally sponsored program designed to demonstrate the Doppler effect in plutonium-oxide-fueled fast reactors. Authors Jerry Havens and Collis Geren draw upon this history to assess the accidental explosion risk inherent in using fast reactors to reduce the energy industry’s carbon dioxide emissions.

If a sufficiently powerful fast-neutron explosion were to cause the containment of a reactor such as SEFOR’s to fail, the reactor’s radiotoxic plutonium fuel could vaporize and escape into the surrounding …

Socio-Ecological Analysis Of Artisanal Gold Mining In West Africa: A Case Study Of Ghana, Richard Takyi, Rasha Hassan, Badr El Mahrad, Richard Adade

Journal of Sustainable Mining

The surge in artisanal gold mining (AGM) activities and the associated environmental impact in Ghana have elicited several stakeholders' attempts to curb the problem. However, due to little understanding of the underlying issues, these efforts have been ineffective. This study aims to use a socio-ecological framework to analyze drivers of AGM activities, the environmental pressures, the state change, their impact on human welfare, and the management response as measures (DAPSI(W)R(M)) to the problem. Evaluate AGM's impact on Ghana's ability to achieve the United Nations Sustainable Development Goals (SDGs). Data were collected from relevant literature on the subject and analyzed with …

Growth Of Invasive Plant Species Communities As A Substantial Issue In Post-Mining Land Development, Paweł Olszewski

Journal of Sustainable Mining

This article concerns the issue of the appearance and growth of invasive plant species in land degraded by hard coal mining and the repercussions of this process, particularly in the context of land reclamation. These species, such as Canadian goldenrod or Japanese knotweed, which nearly always form extensive and monocultural patches of vegetation, contribute to the displacement of both native species and those introduced as part of biological restoration. In 2015, the Central Mining Institute in Katowice prepared a land development concept for a part of the area of the former KWK Paryż mine in Dąbrowa Górnicza (Upper Silesian Industrial …

The Factors Impacting The Incorporation Of The Sustainable Development Goals Into Raw Materials Engineering Curricula, Dimitris Damigos, George Valakas, Anna Gaki, Katerina Adam

Journal of Sustainable Mining

It is widely recognised and acknowledged that the mining industry, if properly operating and managed, has the potential to positively contribute to “The 2030 Agenda for Sustainable Development”. In this direction, the Raw Materials (RM) engineering education possesses a crucial role, given the need to instil in tomorrow’s mining engineers the sustainability principles. This paper explores the educational needs of the Greek RM sector and the factors constituting the RM whole value chain SDGs-education-innovation eco-system. The research follows a two-stage focus group approach. First, the perceptions, opinions and beliefs of invited stakeholders were explored in the context of semi-structured interviews. …

Application Of Synthetic Aperture Radar Interferometry To Monitor Surface Deformations Of The Trans-European Transport Network (Ten-T) – A Case Study Of The Motorways Crossing Areas Of Mining Operations In The Upper Silesian Coal Basin, Poland, Adam Smoliński, Mariusz Stawinoga, Tomasz Pindel

Journal of Sustainable Mining

Underground hard coal mining causes surface deformations. When the mining operations are conducted beneath linear objects, such as motorways, there is a risk of deformations of the axis of the road and its horizontal and vertical alignment (additional bends and vertical curvatures, longitudinal inclinations, deformations of crosssections). In the areas subjected to mining operations, mining plants conduct geodetic monitoring. Due to their labour intensity and costs, geodetic measurements are usually made only a few times a year. The article discusses the possibility of applying Interferometric Synthetic Aperture Radar (InSAR) to monitor the subsidence of the vertical alignment of motorways caused …

Environmental, Health And Safety Intricacies Of Artisanal Mining In The Gold-Rich Landscapes Of Karamoja, North-Eastern Uganda, Eria Serwajja, Paul Isolo Mukwaya

Journal of Sustainable Mining

Artisanal small-scale gold mining presents opportunities for Uganda’s rural poor. However, it also poses serious environmental, health and safety challenges. A suite of data collection methods including interviews, focus groups discussions, water and soils sampling were used to examine the perceptions of miners on the status, prevalence and extent of mercury use in artisanal gold mining, mercury transit routes and toxicity levels of soils and water in Karamoja sub-region. It also explores the health, safety and environmental implications of artisanal small-scale gold mining in the sub-region. The findings show that trade and access to mercury is widespread; although trade in, …

Is The Relationship Between Mining And Climate Change Only One-Way? Climate Change Potential Impacts On Mining Activity – Hazards, Risks And Adaptation Measures, Małgorzata Markowska

Journal of Sustainable Mining

No abstract provided.

The Level Of Securing Dust Deposits Against The Possibility Of Coal Dust Explosion In The Drilled Dog Headings, Bogdan Malich, Krzysztof Cybulski, Malgorzata Wysocka, Krystian Skubacz, Aneta Michałek, Paweł Urban

Journal of Sustainable Mining

The article presents the analysis how the actual coal dust explosion hazard is at the distance of the initial 200 metres of the safety zone maintained along the entire length of driven inclined drift II – face 567 in BRZESZCZE colliery, which was used during realization of the project titled Modelling of the mechanism of explosive coal dust deposition in the vicinity of mined faces in terms of identification, assessment and levelling the possibility of its explosion financed by the National Centre for Research and Development. The mine dust level was between 0.014 kg/m³ and 0.193 kg/m³, …

The Impact Of Precipitation On State Of The Slopes Surface And Thermal Activity Of The Mine Waste Dump – Preliminary Study, Zenon Różański, Paweł Wrona, Grzegorz Pach, Adam Niewiadomski, Tomasz Suponik, Robert Frączek, Leszek Balcarczyk

Journal of Sustainable Mining

Precipitation, especially with a high intensity, affects the condition of mining waste dumps. The article presents the results of research aimed at determining the impact of rain on water erosion on the slopes of a coal waste dump and its thermal state. Preliminary tests of the condition of two slopes of the coal waste dump in Libiąż (Poland) undertaken in the frameworks of the TEXMIN project was carried out using modern geodesy techniques (low-ceiling photogrammetry and TLS terrestrial laser scanning). The current geometry of the slope surface was faithfully reproduced in the form of a cloud of points with known …

Acknowledge Of Reviewers

Journal of Sustainable Mining

No abstract provided.

Investigation Of Anomalous Data Trends During Coal Dust Explosibilty Testing, Jacob Lee Miller

Doctoral Dissertations

Coal dust explosibility is a health and safety concern that has been a recognized hazard for over 100 years. Initial testing by the Author using a Siwek 20L apparatus recorded a secondary maximum pressure at higher dust concentrations (1,000-7,000g/m³) with Pulverized Pittsburgh Coal (PCC). Higher dust concentrations are beyond the typical ASTM E1226 testing procedure but are possible in mining and processing scenarios. No reference documents have been discovered that show a secondary maximum pressure at higher dust concentrations. Literature reviewed identified that once a coal dust concertation generates a peak pressure, the pressure remains constant or decreases …

The Effects Of Rigid Polyurethane Foam As A Confinement Material On Breaching Charge Detonations, Nathan Franz Paerschke-O'Brien

Masters Theses

"The effects of a rigid polyurethane foam used as a confinement material on four types of breaching explosives were tested, focusing on the changes in shockwave peak pressures, detonation load compression forces, and brisance cratering abilities. The Plate Dent testing procedure was modified to incorporate a load cell force sensor, and two air overpressure sensors were included adjacent to the blast to quantify each test result. The testing variables focused on the polyurethane foam cure times and thickness volumes around the breaching explosives to determine the breaching charges' optimal energy output capabilities when confined by the foam material. The rigid …

Relating Detonation Parameters To The Detonation Synthesis Of Nanomaterials, Martin Langenderfer

Doctoral Dissertations

“This research investigates the physical and chemical processes that contribute to the detonation synthesis of silicon carbide nanoparticles. Bulk production of SiC nanoparticles through detonation is possible due to pressures achieved over 20 GPa and temperatures over 2000 K as well as quenching rates in excess of 13 billion K/second. These conditions catalyze reaction and bottom-up molecular growth while retaining particles < 100 nm in diameter. In this work, detonation synthesis of SiC was demonstrated by incorporation of polycarbosilane, an SiC precursor material, into an RDX/TNT explosive matrix prior to detonation. Detonation Synthesis of SiC was also accomplished by reacting elemental silicon with carbon liberated by the detonation of negatively oxygen balanced TNT. Hydrodynamic simulation of a 60:40 mass ratio RDX/TNT detonation created conditions thermodynamically suitable to produce cubic silicon carbide within the first 500 nanoseconds after the passage of the detonation wave while carbon remains chemically reactive for molecular formation. Simulations and experimental tests indicated that loading configuration and impedance mismatch of the precursor additives used in detonation synthesis results in conditions in the additives that exceed the accepted detonation pressure of the explosive by greater than three times. Finally, a full factorial experimental design showed increasing silicon concentration, reducing silicon size, and reducing oxygen balance by adjusting the ratio of RDX to TNT decreased the explosives detonation pressure by 20% and increased the soot yield and concentration of SiC observed in the detonation products by 82% and 442% respectively”--Abstract, page iv.

Investigating The Focusing Effect Of Charge Geometry With Computer Simulations, Witness Plates, And High-Speed Videography, Kelly Ray Williams

Doctoral Dissertations

"Scaled distance is used to calculate a safe standoff radius from the detonation of a known mass of an explosive. It has been shown that varying only the geometry of the charge significantly overdrives regions of the blast wave potentially resulting in hazardous overpressure levels at scaled distance safe radii. Pressure transducers are used to measure overpressure surrounding spherical, cylindrical, and cubic charges to determine if bridge waves were formed at the edges between flat sides as seen in published studies of cylindrical charges. In the fireball field a witness plate is used to evaluate radial energy distribution with a …

Projectile Generator Design For Underground Coal Mine Seal Testing, Ethan Allan Steward

Masters Theses

"Underground coal mines have several dangers, one of the most hazardous of which is the possibility of an explosion caused by the ignition of methane gas. To reduce ventilation costs, coal mines have the option to close off abandoned areas that are no longer active with structural seals to keep an explosion from propagating into working areas of the mine. Though seals have been designed to resist the overpressure, none have been evaluated for their resistance to the impact of heavy objects. Underground explosions produce high velocity gasses that, traveling through mine openings, may propel objects in the mine at …