Applications of Advanced Computational Modelling for Principal Underground Mining Hazards Management and Control

Underground coal mining is facing increased threats from the hazards of spontaneous combustion and heating of coal, abnormal mine gas emissions, and harmful dust concentrations in underground workings, due to increased production outputs and extraction depth of cover. To control and mitigate these engineering problems, there is a need to gain critical knowledge of spontaneous heating in the longwall (LW) goaf, gas migration patterns onto the LW face, and ventilation dynamics and dust dispersion in complex underground environments. Advanced Computational Fluid Dynamics (CFD) modelling can be used to simulate various scenarios portraying these hazards that may occur in underground LWs and provide much-needed knowledge and fundamental science that can be used to develop robust and effective control and mitigation strategies against these hazards. A comprehensive literature review has been conducted to understand these principal mining hazards (PMH), with a particular emphasis on the applications of CFD modelling in the prevention management and control of those PMH arising during coal extraction process. The insufficiencies and gaps in research on spontaneous combustion in active LW goaf, gas migration onto the LW face, and dust dispersion and transport in the development heading were identified. In addition, several field studies were carried out in underground coal mines in Australia to gain a better understanding of these mining issues and collate essential data for the CFD modelling studies. In recent years, goaf heating and spontaneous combustion incidents have been reported in several Australian underground coal mines during normal production cycles. The onset of these heating incidents was dictated by many operational and environmental parameters. Based on the site-specific conditions of an underground coal mine, where the coal seam gas is of approximately 80% carbon dioxide (CO2) and 20% methane (CH4) with a gas emission rate of 2000 l/s, CFD models were developed and validated with field gas monitoring data collected from the Tube Bundle System. The CFD models incorporated a user defined function (UDF) of gas emission and permeability variations in a three-dimensional (3D) space of computational domain representing the LW panels and goaf areas. Simulation results indicated that better goaf inertisation could be achieved when nitrogen (N2) was injected via cut-throughs (C/T) at about 250 m behind the LW face on the maingate (MG) side and surface boreholes at 100 m and 700 m on the tailgate (TG) side, with a total injection rate greater than 1750 l/s. The oxygen concentration on the MG and TG side dropped below 5% at distances of 120 m and 75 m behind the LW face, with a confined oxidation zone area of 35375 m2, which was approximately one-third of the oxidation zone area without inert gas injection. The impact of geological variations (i.e., coal seam orientations and goaf gas composition) on spontaneous combustion prevention and management was further studied using CFD models. The influence of ventilation design and operational parameters (e.g., tightness of the goaf seals) on spontaneous combustion control was also investigated by additional CFD models based on field data. During LW sealing-off, the ventilation flow dynamics change within the goaf, which considerably increases the risk of spontaneous combustion and gas explosion. To prevent these hazards, CFD models were developed and calibrated with field gas monitoring data to simulate a range of operational scenarios of different ventilation arrangements. The modelling studies indicated that at least six gas sensors should be employed and positioned appropriately to ensure effective goaf atmosphere monitoring for risk management during the LW sealing-off process. Extensive CFD-DPM (Discrete phase model) coupling modelling studies were conducted to investigate dust-related issues in LW gateroad development panels. Based on site-specific conditions, a CFD model incorporating a Continuous Miner (CM), Shuttle Car (SC) and exhausting ventilation tube was established and validated with onsite dust monitoring data. Three scenarios of CM cutting at the middle, floor and roof positions were considered and simulated. In all cases, the simulation results indicated that high levels of dust exposure would occur to left-hand-side (LHS) operators and consequently they should be equipped with high-quality personal protective equipment and stay behind the ventilation duct inlet during coal cutting process, while miners standing at the right-hands-side (RHS) of the CM for roof and/or rib bolting and machine operation should stay immediately behind the bolting rig where dust concentration was relatively low. The studies conducted in this thesis provided new insights into the current goaf inertisation practices to effectively manage and control spontaneous heating in LW goaf by considering geological variations and mining design. Furthermore, the CFD modelling study of gas flow dynamics during the panel sealing-off process provides new knowledge of ventilation and goaf gas dynamics, which is critical to the positioning of gas monitoring sensors to reliably measure goaf atmosphere changes, thus minimizing spontaneous heating and gas explosion risks with much-improved mine safety. The research work also shed light on the dust and ventilation behaviour in gateroad development panels, and provided several recommendations for operators’ locations and dust mitigation strategies to improve the health and safety of miners. The research outcomes from this study contribute to the improvement of current practices and guidance for PMH management and control in underground mines and tunnelling projects

Applications of Satellite Earth Observations section - NEODAAS: Providing satellite data for efficient research

The NERC Earth Observation Data Acquisition and Analysis Service (NEODAAS) provides a central point of Earth Observation (EO) satellite data access and expertise for UK researchers. The service is tailored to individual users’ requirements to ensure that researchers can focus effort on their science, rather than struggling with correct use of unfamiliar satellite data

Satellite monitoring of harmful algal blooms (HABs) to protect the aquaculture industry

Harmful algal blooms (HABs) can cause sudden and considerable losses to fish farms, for example 500,000 salmon during one bloom in Shetland, and also present a threat to human health. Early warning allows the industry to take protective measures. PML's satellite monitoring of HABs is now funded by the Scottish aquaculture industry. The service involves processing EO ocean colour data from NASA and ESA in near-real time, and applying novel techniques for discriminating certain harmful blooms from harmless algae. Within the AQUA-USERS project we are extending this capability to further HAB species within several European countries

Earth Resources: A continuing bibliography with indexes, issue 13

This bibliography lists 524 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1977 and March 1977. Emphasis is placed on the use of remote sensing and geophysical instrumentation in spacecraft and aircraft to survey and inventory natural resources and urban areas. Subject matter is grouped according to agriculture and forestry, environmental changes and cultural resources, geodesy and cartography, geology and mineral resources, hydrology and water management, data processing and distribution systems, instrumentation and sensors, and economic analysis

How can optimal sites for mine water geothermal energy systems be identified and where are they in Scotland?

Use of abandoned and flooded mines from across the Midland Valley of Scotland for low-carbon thermal energy provision and storage can assist decarbonisation of Scotland’s heating and cooling demands. This thesis details configurations by which mine water can be harnessed for heating and/or cooling, plus it explores challenges and mitigations associated with conception, funding, project development, construction, lifecycle operation and maintenance of such systems. Mine water geothermal opportunities are present at surface via pumping and treatment schemes, or via contaminated mine drainages, many of which remain untreated. Combining mine water treatment with a thermal energy system provides low-carbon thermal energy whilst resolving local pollution. It is calculated that 48 MW of heat availability is present across Scotland from mine waters at surface. Governing criteria for successful open loop mine water geothermal systems are defined and applied to archival mining data and have created a screening tool for mined workings in Scotland. The resultant Mine Water Geothermal Resource Atlas for Scotland (MiRAS) indicates a total coverage of 370 km2 of suitable locations for mine water geothermal project development across 19 Scottish local authority areas, with the greatest area in North Lanarkshire. Developments in areas affected by shallow mining can incorporate mine water geothermal investigatory boreholes into mandatory ground investigation works to generate a reduced cost geothermal screening technique. A principal finding of this technique is the importance of baseline- and continued hydrogeological and geochemical- monitoring to assess changes to mine water system dynamics, facilitating project longevity. Oxygen and hydrogen isotopic signatures infer meteoric recharge for mine drainages and subsurface mine water. Sulphur isotopes from sulphate in mine waters corresponds with standard sulphide oxidation in some instances, but also showed influence from heavier sources reflecting possible evaporite dissolution, ancient evaporitic brines, bacterial reduction or inclusion of carbonate associated sulphur.Use of abandoned and flooded mines from across the Midland Valley of Scotland for low-carbon thermal energy provision and storage can assist decarbonisation of Scotland’s heating and cooling demands. This thesis details configurations by which mine water can be harnessed for heating and/or cooling, plus it explores challenges and mitigations associated with conception, funding, project development, construction, lifecycle operation and maintenance of such systems. Mine water geothermal opportunities are present at surface via pumping and treatment schemes, or via contaminated mine drainages, many of which remain untreated. Combining mine water treatment with a thermal energy system provides low-carbon thermal energy whilst resolving local pollution. It is calculated that 48 MW of heat availability is present across Scotland from mine waters at surface. Governing criteria for successful open loop mine water geothermal systems are defined and applied to archival mining data and have created a screening tool for mined workings in Scotland. The resultant Mine Water Geothermal Resource Atlas for Scotland (MiRAS) indicates a total coverage of 370 km2 of suitable locations for mine water geothermal project development across 19 Scottish local authority areas, with the greatest area in North Lanarkshire. Developments in areas affected by shallow mining can incorporate mine water geothermal investigatory boreholes into mandatory ground investigation works to generate a reduced cost geothermal screening technique. A principal finding of this technique is the importance of baseline- and continued hydrogeological and geochemical- monitoring to assess changes to mine water system dynamics, facilitating project longevity. Oxygen and hydrogen isotopic signatures infer meteoric recharge for mine drainages and subsurface mine water. Sulphur isotopes from sulphate in mine waters corresponds with standard sulphide oxidation in some instances, but also showed influence from heavier sources reflecting possible evaporite dissolution, ancient evaporitic brines, bacterial reduction or inclusion of carbonate associated sulphur

Друга міжнародна конференція зі сталого майбутнього: екологічні, технологічні, соціальні та економічні питання (ICSF 2021). Кривий Ріг, Україна, 19-21 травня 2021 року

Second International Conference on Sustainable Futures: Environmental, Technological, Social and Economic Matters (ICSF 2021). Kryvyi Rih, Ukraine, May 19-21, 2021.Друга міжнародна конференція зі сталого майбутнього: екологічні, технологічні, соціальні та економічні питання (ICSF 2021). Кривий Ріг, Україна, 19-21 травня 2021 року

The Effects of Advanced Analytics and Machine Learning on the Transportation of Natural Gas

This qualitative single case study describes the effects of an advanced analytic and machine learning system (AAML) has on the transportation of natural gas pipelines and the causes for failure to fully utilize the advanced analytic and machine learning system. This study\u27s guiding theory was the Unified Theory of Acceptance and Use of Technology (UTAUT) model and Transformation Leadership. The factors for failure to fully utilize AAML systems were studied, and the factors that made the AAML system successful were also examined. Data were collected through participant interviews. This study indicates that the primary factors for failure to fully utilize AAML systems are training and resource allocation. The AAML system successfully increased the participants\u27 productivity and analytical abilities by eliminating the many manual steps involved in producing reports and analyzing business conditions. The AAML system also allowed the organization to gather and analyze real-time data in a volume and manner that would have been impossible before the AAML system was installed. The leadership team brought about the AAML system\u27s success through transformation leadership by encouraging creativity, spurring innovation while providing the proper funding, time, and personnel to support the AAML system