Copper from dump, heap, and in situ leaching accounts for about 15% of United States copper production. In situ leaching is the least understood and most difficult to evaluate of these leaching methods. Several types of supergene copper deposits are derived from porphyry copper systems depending on the geologic and climatic factors involved in the formation of a deposit. The geologic and climatic factors involved in the formation of a deposit. The geologic evaluation of a deposit should provide most of the basic information required to access a deposit for in situ leaching. Metallurgical testing can determine the leachability and acid consumption of the ore as well as the need for an oxidizing agent through the use of agitation and column leaching tests. The location of the deposit with respect to the water table determines the type of ground preparation required. Hydraulic fracturing can be used for deposits below the water table and blasting or caving can be used for deposits above the water table. Fluid flow through the deposit depends on the method of application, the permeability of the deposit, and the method of egress from the deposit. The leaching of a copper "oxide" deposit depends on the strength and volume of sulfuric acid which reaches the ore. The leaching of a copper sulfide deposit depends on an oxidant as well as sulfuric acid reaching the ore.

A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in Engineering. Johannesburg, 2017 / The primary objective of any mining business unit is to make profit by extracting, processing and selling minerals from a particular mineral deposit. It is important to optimise the extraction of the mineral resource given time, space and resource constraints. The mineral extraction process is often associated with uncertainty due to variable technical and human factors. Technical factors such as grade distribution, ground conditions and equipment reliability influence the performance of the mining production system (MPS). The performance of the MPS is also impacted by human factors such as employee skills, health and attendance. Uncertainty associated with technical and human factors often leads to planned output being different to actuals obtained. Therefore an in-depth analysis of the significant causes of deviations from the planned outcomes becomes a very important exercise. This research investigated the empirical relationships between inputs and outputs in a MPS in order assist management in directing efforts at key production drivers. A literature review revealed that production output is an end result of a chain of processes dependent and directly linked to each other, often referred to as the Mining Value Chain. The processes can be seen as milestones to be achieved within a production project. The process requires technical and human factors as resources. The literature review also highlighted that the production stage is the most obvious stage for investors to realise their return on investment. The production stage which constitutes a MPS was chosen as a relevant research area for the reason mentioned. Once a MPS has been empirically characterised, more effort and resources can be focused on the key decision making variables (DMVs) in order to meet the planned outcomes. A production function was developed accordingly, based on the production logic and historical data. The research concludes that for a typical platinum mine the face advance, face length mined, number of teams, and team size (independent variables) have a statistically significant relationship with the centares (m²) (dependent variable / response variable) produced which is a key performance indicator (KPI) for a platinum mine. A statistically significant regression equation with a coefficient of determination R2 = 0.99835 was obtained for the MPS. The production function can be used to align the physical, technical and human factors together to predict the optimal output level. The production function also highlights that the most significant production lever of the MPS is the face advance, contrary to a commonly held sentiment that lost blasts are the most significant. / MT 2017

This study explores the potential extension of occupational health and safety to informal small scale miners in South Africa. It was motivated by an understanding of the integral but much neglected relationship between the quality of work and the goals of poverty reduction and economic development. The study recognises that poor working conditions can reduce productivity and that work-related injury or illness is an unaffordable risk for those working without access to adequate social protection. Further, the protection of labour standards, including work health and safety, is an established basic right in those countries where relevant LLO Conventions have been ratified. Conventional occupational health and safety (OHS) regulation operates through formal employment structures and therefore offers limited or no protection to informal workers. In a country where increasing policy attention is being paid at national and local level to the employment and economic growth potential of the informal economy, this study practically explores within one sector - mining - how the institutional positions of both conventional and identified non-conventional OHS stakeholders work to constrain, or provide opportunities for, the extension of health and safety protection to those working informally. The focus on one kaolin and one clay/coal informal small scale mine site within KwaZulu-Natal and the use of in-depth interviews with workers and a range of identified stakeholders enabled a structured qualitative investigation into the health and safety challenges faced by informal miners; the nature of the support provided to small scale mining by the Department of Minerals and Energy (DME); and the institutional processes acting through national, provincial and local structures that do or could influence workers' access to OHS. The threats presented by each mine to worker and public, as well as environmental health and safety were found to be numerous and severe. There was also evidence of a negative impact of poor working conditions on both the health and economic security of the workers. Despite this, the study identified a vacuum of accountability for the labour protection of informal miners. Conventional mining OHS mechanisms are vertically driven, resource intensive and technocratic. They are both inappropriate for and inflexible towards meeting the challenges presented by informal work. In a minority of cases interdependent links between the responsibil ities of non-conventional OHS stakeholders and work health and safety are understood, but the lack of a worker focus, the institutional boundaries within which people work, their limited OHS knowledge, and the major financial and human resource constraints they face, appear to present significant barriers to any actual OHS intervention. Through the research process it became clear that the management and nature of the DME's small scale mining support strategy itself present fundamental barriers to the extension of OHS. The strategy is a product of a narrow conceptual isation of what is needed to achieve formalisation. This, and the lack of genuine worker representation and accountability within it, means that not only does the strategy fail to attend to OHS and a variety of other worker needs, but that the DME continues unchallenged in its neglect of such issues. With an understanding of the real constraints faced by both workers and the range of identified OHS stakeholders, and in view of the future plans to overhaul the existing national OHS framework in South Africa, the study concludes by outlining some practical opportunities and recommendations that could help to break down existing barriers to the OHS protection of informal workers. Conventional OHS mechanisms could be reoriented to take advantage of cheaper, simpler and more appropriate workerled approaches which could potentially achieve substantial improvements for large numbers of informal workers. Realistic opportunities also exist to more firmly secure the participation of promising non-conventional OHS stakeholders including, in this case, formal mining companies and local government. Finally, there are ways to bridge existing deep divides between social and economic institutional responsibilities that currently serve to obscure potential resource sharing and multiplier impact opportunities of working more collaboratively to improve OHS for the benefit of informal workers. / Thesis (M.Dev. Studies)-University of KwaZulu-Natal, Durban, 2006.

Thesis (PhD) -- Macquarie University, Division of Environmental and Life Sciences, Department of Human Geography, 2007. / "November 2006". Bibliography: p. 352-398.

Thesis (M. Sc.)--Carleton University, 1992. / Also available in electronic format on the Internet.

No description available.

M.Ing. / Safety within the mining industry is a primary concern for everyone involved. More specifically, active below-ground stope support for South African Mines is becoming increasingly important due to a renewed emphasis on the safety and well-being of the people actually working underground. It is imperative that all stope support systems are rigorously tested, continuously, both under laboratory conditions and in-situ to prove their performance and manufacturing standards. The Rocprop was initially manufactured in 1995 with the first two hundred props being installed at East Driefontein Consolidated Gold Mine in the Carletonville area. In the three years since the first introduction over three hundred thousand Rocprops have been manufactured and sold to South African Mines with the number steadily increasing. The Rocprop is a tubular support consisting of two tubes — a Ø139mm 'inner' tube and a Ø152mm 'outer' tube. One end of each tube is sealed by dome ends which are welded onto the tube mouths. The two tubes, cut to identical lengths, fit inside one another and extend telescopically during installation. Once the desired height has been reached, leaving enough tube overlapping to ensure the support does not buckle, the wedge is hammered in locking the prop at that height. The water is then removed after which the prop will provide active support of the rock mass above it. One of the components responsible for the Rocprops success is a dome end. This is either a forging or a pressing welded onto each end of the support and allows continual concentric loading throughout the life of the Rocprop. At present the dome ends are pressings, manufactured into hemispheres from 10mm mild steel plate in one action. The reason for the Rocprop's success is its performance characteristics. It's all metal construction, ease of installation, reliability and predictability in both seismic and static conditions, fire resistance, blast resistant, economically viability and versatility have made the prop successful. Reasons for the research were to investigate the dome end forming process in general and to investigate current numerical analysis techniques ability to predict loads during manufacture, the final shape, spring-back and other local deformation areas. Also to investigate alternate manufacturing methods such as cold forming, which provides advantages such as better mechanical properties and higher structural capabilities. The use of alternate materials in the Rocprop manufacture has been an ongoing process for MSP, manufacturer and current licensee holder of the Rocprop. A substitute for the current dome end manufactured from mild steel was investigated. For the substitute to be viable the material should be stronger, weigh less and be cost effective. In depth knowledge about the forming of the dome end at various velocities was gathered, providing information for further optimisation of the component.

M.Com. / The objective of this study was to address problems pertaining to the effectiveness of hostel representative structures within the mining industry. As part of the study, it was thought pertinent to interview hostel representatives themselves, in order to establish areas in which improvement could be made. The actual approach was to determine the roles and responsibilities of the hostel representatives and gain suggestions from hostel representatives themselves on the causes of inefficiencies of hostel representative structures. In addition, hostel accommodation preferences were determined; by identifying major functions of the hostel representatives, problems reducing their effectiveness, hostel structures which are more effective, and the reasons of their effectiveness. Views of management and representative structures were also determined; this was done by identifying the degree of trust in both mine and hostel management to look after the interests of the hostel representatives. In addition, effectiveness of various hostel representative groupings was determined. Different forms of worker representative structures on the mine were identified and discussed. The theoretical model of forms of worker participation was discussed to further assist in conceptually clarifying the wide field of worker participation. The actual results reported from this study seem to indicate that: hostel representatives' major functions are; disciplinary, communication, domestic, legal, dispute resolution and hostel management deputising functions. Problems that reduce the effectiveness of the hostel representatives were hostel intruders and undisciplined residents, lack of maintenance in the hostel, lack of protective clothing, mine management undermining of the hostel representatives, hostel committee's failure to follow constitution, a lack of promotional opportunities, power struggle union and management structures. In addition, having to consult with other representative structures caused delays in case settlement. Lack of remuneration of the hostel representatives reduced the effectiveness of the hostel representatives. Role conflict between underground work and representative role was also a hindrance to the hostel representatives. Failure of the hostel representatives to attend meetings was also a cause which reduced the effectiveness of the hostel representatives. The Tribal Prefect is considered as more effective than the Block Stewards, the Administration Assistants and the Hostel Committee Members. The Administration Assistants are perceived as most effective in looking after the interests of hostel employees than other hostel representatives.

Please read the abstract in the 00front part of this document / Dissertation (MSc (Mining Engineering))--University of Pretoria, 2007. / Mining Engineering / unrestricted

Please read the abstract in the section 00front of this document / Dissertation (M Eng (Electrical Engineering))--University of Pretoria, 2007. / Electrical, Electronic and Computer Engineering / unrestricted