Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains x, 162 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references (p. 160-162).

The gold mining fIrm in South Africa is viewed as a normal fIrm producing gold bearing ore but faced with a quality constraint (grade). Grade, however, is never uniformly distributed in a metalliferous deposit and because high grades are mined fIrst, the quality constraint becomes increasingly severe with cumulated production. The fIrm will continue to mine gold bearing ore until it reaches its mining limit where the marginal cost of recovering the gold is equal to the marginal revenue received from that gold and at that point the economic deposit becomes exhausted. Because the mining limit is determined by cost/technology and price, it is not fIxed and thus the point of economic exhaustion may change. When high grades are mined fIrst the relationship between the tonnage of gold ore and the grade describes the rate at which the grade is expected to fall with cumulated production. In this thesis, the grade for South African Witwatersrand gold producers is modelled to fall exponentially. The mining limit, determined by costs/technology and price, can be expressed in terms of grade. By predicting the decay in grade relative to the tonnage of gold ore and applying a mining limit, a life-time size of the economic deposit can be estimated. The remaining life of a producing gold mine can then be determined and the flow of gold predicted. An empirical treatment using the disk model of a gold deposit is undertaken for a gold mine, a goldfIeld and the total Witwatersrand gold deposit. A dynamic econometric analysis of expected mining costs and gold prices is not attempted; however certain examples are used to illustrate the applicability of the model and the influence of the South African gold mining tax formula on the life of the mine.

Thesis (MTech (Chemical Engineering))--Cape Technikon, 2000. / Internationally, there is an increase in the need for safer environmental processes that can be applied to mining operations, especially on a small scale, where mercury amalgamation is the main process used for the recovery of free gold. An alternative, more environmentally acceptable, process called the Coal Gold Agglomeration (CGA) process has been investigated at the Cape Technikon. This paper explains the application of flotation as a means of separation for the CGA process. The CGA process is based on the recovery of hydrophobic gold particles from ore slurries into agglomerates formed from coal and oil. The agglomerates are separated from the slurry through scraping, screening, flotation or a combination of the aforementioned. They are then ashed to release the gold particles, after which it is smelted to form gold bullion. All components were contacted for fifty minutes after which a frother was added and after three minutes of conditioning, air, at a rate of one I/min per cell volume was introduced into the system. The addition of a collector (Potassium Amyl Xanthate) at the start of each run significantly improved gold recoveries. Preliminary experiments indicated that the use of baffles decreased the gold recoveries, which was concluded to be due to agglomerate breakage. The system was also found to be frother-selective and hence only DOW-200 was used in subsequent experiments. A significant increase or decrease in the air addition rate both had a negative effect on the recoveries; therefore, the air addition rate was not altered during further tests. The use of tap water as opposed to distilled water decreased the attainable recoveries by less than five per cent. This was a very encouraging result, in terms of the practical implementation of the CGA process.

Ph.D. (Mineral Economics) / Please refer to full text to view abstract

M.Sc. / The potential target areas for coalbed methane in South Africa are reviewed and a case study based on borehole data from the north-eastern Karoo basin was undertaken. The Early Permian coal seams of the Karoo Supergroup occur in several discrete sedimentary basins in South Africa, of which the Karoo basin is the largest. Using screening criteria based on geological, petrographical and analytical data some of the coal deposits can be excluded as potential coalbed methane producers. These include the Molteno Coalfield, large parts of the Karoo basin coal deposits and some of the Northern Province's coal deposits which are structurally disturbed. The traditional mining areas in the Free State, Witbank and Highveld coalfields are excluded from the coalbed methane study because the target seams occur at less than 200 metres below surface, too shallow for gas retention. Some of the coal seams in the Waterberg Coalfield occur at depths of several hundred metres below surface and these are unlikely to be mined by conventional means. These deep coals may be ideal coalbed methane producers. This regional overview was based on available, published data and two important parameters, permeability of coal and coalbed hydrology are unknown but important factors that will need to be taken into account in any future evaluations. The case study focused on an area close to Amersfoort that has a predicted potential for coalbed methane production. The study utilized 465 borehole descriptions from which isopach maps and geological cross-sections were constructed. Limited samples of borehole core provided lithological information from which a facies analyses was undertaken so as to establish the hydrodynamic origin of each facies types. The main lithofacies associated with the coal seams are mudstones, carbonaceous shales and fine- to coarse-grained sandstone. These data were combined with analyses from limited permeability data, petrographical data and proximate analyses for the Gus and Alfred seams. In addition to the sedimentary rocks, the role of dolerite intrusions was found to be significant as these occur as thick sills and dykes that occur below, within and above the coal seams. These may compartmentalize the seams into secondary targets within the study area. Thick sills overlying the coal zone also increase static loading and may be advantageous with respect to reducing the minimum depthbelow- surface requirements. Potential coalbed methane target areas are identified, although the entire study area is not suitable due to structural displacement of the coal seams, thinning of coal in places and devolatization caused by the dolerites.

M.Sc. / The gold mining industry in South Africa is exposed to various legal issues due to the nature of its operations. Furthermore, there has been a renewed focus on environmental management in South Africa over the past decade, as well as an international focus on sustainable development. Environmental management in the gold mining industry must incorporate sustainable development, as well as the ‘cradle to grave’ concept. The gold mining industry has to ensure that its activities are compliant with environmental legislation and best practice requirements, as the increase in environmental awareness and legislated principles has escalated gold mines’ exposure to demands for the remediation and reparations of pollution and environmental degradation. No single document exists that provides the gold mining industry with detail on the environmental legislation and best practice requirements that gold mines are able to refer to in order ensure effective environmental management. Furthermore, there is no implementation plan for gold mines to implement in order to achieve compliance with environmental legislation and best practice requirements. This study has presented such a document, as it has provided the reader with detail concerning the responsibilities of the regulatory authorities, the current and new legislation, best practices, codes of practices, and offences and liabilities that gold mines will become exposed to should they not adhere to environmental legislative requirements. This detail has been used to compile an implementation programme (Chapter 4), which when implemented will ensure environmental compliance for the gold mining industry in South Africa. This mini-dissertation has thus provided the gold mining industry with an overview from which to work in order to become legally compliant with issues pertaining to environmental management in South Africa.

M.Sc.

M.Sc. (Geology) / The study aims to provide a geometallurgical assessment, including an evaluation of the response of different facies types of the Merensky Reef to mineral processing, and the identification of critical characteristics that determine processing behaviour. This is accomplished by obtaining quantitative mineralogical information, combined with chemical assay, laboratory scale milling and flotation testing. Lonmin Platinum’s Marikana Mine is located on the Western Limb of the Bushveld Complex to the east of Rustenburg. Platinum group elements (PGE) occur in, and are mined from, a variety of facies types of the Merensky Reef, and the UG2. For the purpose of the present study, three facies types of Merensky Reef samples and one sample of UG2 were used. The Merensky facies samples comprise of the BK, RPM, and Western Platinum variants. The mineral assemblages of the various Merensky Reef facies types at this locality comprise varying amounts of orthopyroxene, clinopyroxene, plagioclase, olivine, talc, serpentine, chlorite, chromite, magnetite and sulphides (mainly pyrrhotite, pentlandite and chalcopyrite). Approximately 20 individual 10 cm channel samples were collected from each of the facies variants of the Merensky Reef, and the UG2. These are coarsely crushed, mineral modal abundances determined using the MLA, and then analysed for Co, Cr, Cu, Ni, S and 6 PGE. The samples were then combined per facies type, and each of these composites subjected to laboratory scale milling and flotation testing. Abundant sulphide typically occurs with (is associated with) thin chromitite stringers, as is commonly observed in the Merensky Reef throughout the whole of the Bushveld Complex. Chromitite stringers are characterized by high PGE concentrations. The milling behaviour of the various facies samples, as well as flotation behaviour, was observed to be a function of mineralogy. The influence of ore mineralogy on the various stages of flotation, the mineralogical makeup of the various flotation concentrates, and the level of recovery of the PGE’s during flotation, were also investigated. Ore facies having the most abundant anorthite required the longest milling time to achieve the target grind of 60wt.% passing 75μm; and the ore with the most abundant enstatite produced the largest mass pull on floating. The facies with higher PGE grade, modal abundance of base metal sulphides, higher degree of liberation of base metal sulphides and least enstatite abundance produced the most favourable set of characteristics for efficient PGE recovery.

Magister Scientiae - MSc / The waste products acid mine drainage formed during coal mining and fly ash from coal burning power generation, pose substantial environmental and economic problems for South Africa. Eskom has developed a remediation system employing alkaline fly ash to neutralize and precipitate heavy metals from toxic acidic acid mine drainage streams. The aim of this study was to assess the microbial diversity in and microbial impact on this remediation system. / South Africa

Coal mining in nineteenth century British Columbia was confined almost exclusively to the tidewater coal measures of Vancouver Island where it was expanded rapidly from 1871 to 1891. This dissertation's purposes are to describe the coal industry's rise, account for its fast growth in the seventies and eighties, and assess the coal trade's general impact upon the region's economy. The approach is thematic, focusing in turn upon coal lands, capital, management, labour, technology, markets, production, and productivity. Standard research, organization, and interpretation methods for economic history are followed, including thorough descriptive use of statistical data. Comparisons are intensive and far-reaching, resulting in a close-knit framework upon which important conclusions are based. No effort has been made, however, to offer extensive biographical information on the coal trade's leading personalities. These studies confirm the coal industry's rapid expansion, and determine that all factors of production can explain that phenomenon with a high degree of certainty, though market demand and management technique do so more readily than other agents. It is shown that management methods and styles evolved quickly, the most effective being the owner-manager type as practiced by Robert Dunsmuir, the industry's most successful proprietor. Risk capital was drawn from various sources, including mainly British direct investments, local savings, partnerships (often involving foreign investors), and ploughed-back profits. Entrepreneurs and promoters were active in attempting to develop coal properties from 1864 on, though only those highly experienced in mining and management succeeded. Chronic worker shortages, coupled with the physical problems associated with coal mining in mountainous terrain, forced coal operators to opt early for labour saving technology imported almost exclusively from Britain. The introduction of large numbers of Oriental colliers by Dunsmuir after 1870, (who were willing to work at half the wages whites would), slowed the technological advance of the industry, but not annual rates of production increases. Considerable friction between white workers and management resulted from the latter's initiatives with Oriental labour, while the owners' policy of severely restricting wage-rates caused further serious labour problems, including a high number of work stoppages. Mine safety, job security, and general working conditions also were contentious issues. B.C.'s early collieries relied heavily upon the California market which often was unsteady, but which accounted for approximately seventy-five percent of all sales during the years 1849-91. Domestic users were mainly shipping companies, light industry, and households. Much of the local market was handled at the pithead. The major coal companies streamlined their channels of distribution by opening their own sales offices in Victoria and San Francisco, and. in the case of Dunsmuir, by also building a collier fleet and a railway of his own. The coal industry had a major influence upon southern Vancouver Island's economy, but not a large impact upon the remainder of the province. No determined "attempts were made by coal proprietors or other capitalists to create secondary industries linked to coal production, though colliery owners did invest in land, transport, and retail-wholesale ventures designed either to service their mining activities or to diversify their personal holdings. Such moves occurred later-on, however, as the main thrust of their initial efforts was to establish and maintain the coal trade with California. / Arts, Faculty of / History, Department of / Graduate