A research report submitted to the Faculty of Engineering and the Build Environment, University of the Witwatersrand, in partial fulfillment of the requirements for the degree of Master of Science in Engineering Johannesburg, 2014 / The South African power crisis and corresponding rising costs experienced since 2008, created a paradigm shift in terms of electricity use. The mining sector is the second highest consumer of electricity with metalliferous mines being accountable for 80% of the total power. Recent studies revealed that underground ventilation and cooling accounts for 30% to 40% of total electricity costs in an underground metalliferous mine. Hence the need to look at ways to reduce electricity consumption in ventilation and cooling. Work has been done on optimising efficiencies of ventilation and refrigeration systems of underground mines. Currently, the high energy consumption is driven by efforts to achieve a thermally acceptable environment for workers (manned) in deep metalliferous mines which is currently between 27ºC (wb) and 29ºC (wb). However, no detailed study has been done looking at increasing thermally acceptable environments for deep level metalliferous mine. In this study the impact of increasing rejection temperature to 40ºC (db) was assessed in the automated (unmanned) scenario at a maximum depth of 2811 metres. Then the power demand was compared with the manned scenario. The results proved that automation in an underground mine has the potential of reducing electricity cost of ventilation and cooling by more than 50%. For example, the production rate of about 200 kilo-tons per month yield an annual cost saving of R71 million on electricity. These cost savings can be used to justify automation systems. Automation removes workers from the hazardous environment and replaces them with equipment which can withstand harsher conditions. The introduction of an automation system in underground mines would not come risk-free. Currently, automation systems have not yet reached a level of removing workers completely from underground.There are instances that would require workers to enter production zones. A Bow-Tie risk analysis was used to show the hazards that workers would be exposed to and prevention controls and responses to mitigate the impact the risks. / MT2017

Thesis (M.S.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains viii, 81 p. : ill. (some col.), col. maps. Includes abstract. Includes bibliographical references (p. 61-62).

This thesis describes work that has been carried out to develop a scaled down laboratory test bed for use in the optimisation of fan driven air ventilation systems found at the various Anglo Coal South African mines. The present system involved in the movement of air underground comprises a fixed speed centrifugal fan driven damper controlled system. National Power Contractors (NPC) together with the University of KwaZulu-Natal (UKZN) proposed a variable speed automated controlled system, but the costs of installing Variable Speed Drives (VSD) and their impact on the energy consumption of a system prior to being installed are important. In addition deliverables required by the industrial partner NPC was to develop a calibrated simulation model where any fan system could be simulated showing potential energy savings. A test bed was therefore constructed to evaluate the power usage of a VSD while driving a simulated fan. The test bed comprised of two Field Oriented Controlled induction machines. A ventilation system at Anglo Coal’s Vlaklaagte colliery was proposed to be simulated by the test bed to develop the Measurement and Verification (M&V) methodology required to represent a business case, but since data from this fan system was not available two other fan systems were studied. One fan system was built at the UKZN whilst the other industrial fan system was at Anglo Coal’s Greenside colliery. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2010.

Thesis (M.S.)--University of Nevada, Reno, 2008. / "August 2008." Includes bibliographical references (leaves 52-55). Online version available on the World Wide Web.

Thesis (M.S.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains viii, 70 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 69-70).

Thesis (M.S.)--University of Wisconsin--Madison, 1966. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 1999. / Title from document title page. Document formatted into pages; contains x, 98 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 75-78).

Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains vii, 63 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 52-53).

Tracer gas surveys are a powerful means of assessing air quantity in underground mine ventilation circuits.  The execution of a tracer gas style ventilation survey allows for the direct measurement of air quantity in locations where this information is otherwise unattainable.  Such instances include inaccessible regions of the mine or locations of irregular flow.  However, this method of completing a mine ventilation survey is an underused tool in the industry.  This is largely due to the amount of training required to analyze survey results. As well, the survey is relatively slow because of the time required to perform analysis of results and the time required to allow for the total elution of tracer compounds from the ventilation circuit before subsequent tracer releases can be made.  These limitations can be mitigated with the development of a protocol for a novel tracer gas which can be readily implemented with existing technology.  Enhanced tracer gas techniques will significantly improve the flexibility of ventilation surveys.  The most powerful means to improve tracer gas techniques applied to mine ventilation surveys is to alter existing protocols into a method that can be readily applied where tracer surveys already take place. One effective method of enhancing existing tracer gas survey protocols is to simply add a second tracer gas that can be detected on a gas chromatograph -- electron capture detector (GC-ECD) using the same method as with the existing industry standard tracer, sulfur hexafluoride (SF6).  Novel tracer gases that have been successfully implemented in the past called for complex analysis methods requiring special equipment, or were designed for inactive workings.  Experimentation with perfluoromethylcyclohexane (PMCH) and SF6 allowed for ideal chromatographic results.  PMCH is a favorable selection for a novel tracer to work in tandem with SF6 due to its chemical stability, similar physical properties and detection limits to SF6, and its ability to be applied and integrated into an existing system.  Additionally, PMCH has been successfully utilized in other large-scale tracer gas studies. Introduction of a novel tracer gas will make great strides in improving the versatility of underground tracer gas ventilation surveys, but further improvement to the tracer gas technique can be made in simplifying individual steps.  One such step which would benefit from improvement is in sampling.  Solid phase microextraction (SPME) is a sampling method that is designed for rapid sampling at low concentrations which provides precise results with minimal training.  A SPME extracting phase ideal for trace analysis of mine gases was selected and a GC-ECD protocol was established.  The protocol for fiber selection and method optimization when performing trace analysis with SPME is described in detail in this thesis.  Furthermore, the impact of sampling with SPME under varying turbulent conditions is explored, and the ability of SPME to sample multiple trace analytes simultaneously is observed. / Master of Science

Spontaneous combustion occurring in inaccessible areas of underground coal mines is often intractable. Even though routine inspection and/or continuous monitoring help detect the incubation of spontaneous heatings, they may not be able to identify the locations with accuracy. Moreover, implementation of remedial measures is difficult. A new approach to ventilation system design to overcome the problem is investigated in this dissertation. Ventilation layouts are analyzed to identify potential problem areas and nullify the probability of fire occurrence. The focus is directed to longwall gobs. The changing gob characteristics, especially the varying degree of consolidation at different parts of a gob as the face moves, is considered. Analytical studies and computer modeling show that bleederless ventilation in retreating panels is promising. The W -system of ventilation is most suitable. However, there may be difficulties in maintaining the middle entry in a Wsystem / Ph. D.