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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Notes relative to the ores occurring at Mercur, Utah together with a general description of the metallurgical practices applied to them at DeLaMar's Mercur Mines

Jackling, Daniel Cowan, January 1900 (has links) (PDF)
Thesis--University of Missouri, School of Mines and Metallurgy, 1900. / The entire thesis text is included in file. Typescript. Title from title screen of thesis/dissertation PDF file (viewed February 3, 2009)
92

Synthesis and reactivity of gold (I) thiolate cluster complexes /

Abdou, Hanan E., January 2001 (has links)
Thesis (M.S.) in Chemistry--University of Maine, 2001. / Includes vita. Includes bibliographical references (leaves 87-90).
93

Silver, gold, and paper

LEE, Chee Boon 01 August 1939 (has links)
No description available.
94

Vacancy concentration and precipitation in quenched pure gold and gold-silver alloys /

Fraikor, Frederick John January 1965 (has links)
No description available.
95

The theory of gold supply : with special reference to the problems of the Witwatersrand

Busschau, William John January 1936 (has links)
No description available.
96

Description of El Paso Consolidated Gold Mine

Perkins, Edwin Thompson. January 1902 (has links) (PDF)
Thesis--University of Missouri, School of Mines and Metallurgy, 1902. / Edwin T. Perkins determined to be Edwin Thompson Perkins from "Thirty-Third Annual Catalogue of the School of Mines and Metallurgy". The entire thesis text is included in file. Typescript. Illustrated by author. Title from title screen of thesis/dissertation PDF file (viewed November 13, 2008)
97

A study of the effect of annealing temperature of gold foil on the surface hardness and handling characteristics thesis submitted in partial fulfillment ... [operative dentistry] /

Zarb, George A. January 1961 (has links)
Thesis (M.S.)--University of Michigan, 1961.
98

A study of the effect of annealing temperature of gold foil on the surface hardness and handling characteristics thesis submitted in partial fulfillment ... [operative dentistry] /

Zarb, George A. January 1961 (has links)
Thesis (M.S.)--University of Michigan, 1961.
99

An environmentally sound gold recovery process for small-scale gold mining

Bouwer, Wendy January 1999 (has links)
Thesis(MTech (Chem.Eng.Technology))--//Cape Technikon, 1999 / The gold mining industry has mainly relied upon the use of a highly polluting chemicals, such as mercury and cyanide, to recover gold from its ores. As environmental legislation has become more stringent in all countries and environmental protection has become the focus of world-wide research, development of environmental sound processes has been favoured. The Coal Gold Agglomeration (CGA) process is such a process which was developed some years ago and has the advantage in that gold is recovered by a procedure which has little or no effect on the environment. The CGA process is based on the hydrophobic characteristics of coal, gold and oil. Gold particles which are substantially free become attached to the coal-oil agglomerates during collision, and eventually penetrate into the agglomerates. The resulting agglomerates are recycled to increase the gold loading, separated from the slurry, burnt, ashed and smelted to produce gold bullion. Laboratory scale batch tests were performed on an artificial/synthetic gold ore, containing fine gold powder. The slurry was contacted with a mixture of coal and oil. i.e. coal-oil agglomerates, after which both the agglomerates and ore were analysed for gold. Operating parameters, such as the mode of contact between the coal-oil phase and the gold containing slurry, contact time of the slurry and the coal-oil phase, means of separating the coal-oil gold agglomerates from the slurry, coal to ore, coal to oil and water to ore ratios, type of oil, effect of collectors and the mineralogy of the ore on the gold recovery were investigated. Results have shown that stirring the coal-oil phase and the slug yielded higher gold loadings than shaking and the traditional rolling bottle technique. BI increasing the time of contact between the coal-oil phase and the gold slurry. the final gold loading in the agglomerates increases, until an equilibrium value is reached. An increase in the amount of coal, together with a decrease in the amount of water used in the slurry, has shown to increase gold recoveries. Furthermore, by varying the concentration and volume of a collector. such as potassium amyl xanthate (PAX) enhanced the settling rate and enabled the effectiveness of separation. Moreover, it was found that the gold loading on the coal-oil phase increased after recycling it. Further tests were performed on a real ore sample and after X-ray Diffraction (XRD) analysis, it was found that certain minerals other than gold was transferred to the coal-oil phase. The theoretical foundation of the CGA process is based on the difference in free energy and was expressed as a function of the interfacial tensions and three-phase contact angles between gold, oil and water, together with the ratio of coal-oil agglomerate to gold particle radii, as the free energy is a measure of the thermodynamic stability and hence, partly a measure of gold recoveries, meaningful predictions as to gold recoveries were made by performing a sensitivity analysis on the variables connected to the free energy, It was, however, found that some operating parameters, which were linked to other factors, such as the maximum gold transfer into coal-oil phase and the separation efficiency of the agglomerates. were vital to be taken into account when predictions as to gold recoveries were made. Therefore, the gold recoveries were found to be a function of the thermodynamic stability as well as the maximum gold transfer into the coal-oil phase and the separation efficiency of the agglomerates, The meaningful information gained by performing the theoretical investigations were applied and linked to gold recoveries, thereby providing useful explanations as to the typical gold recoveries obtained during experimentation. A comparative study on mercury amalgamation was done to evaluate the performance of the CGA process. It was found that the CGA process yielded better gold recoveries than amalgamation, which makes it the better process both in terms of recoveries as well as environmental safety, A further application of the theoretical knowledge was, however, very useful to explain the tendency of the CGA process yielding the better results.
100

Innovations in gold extraction

Davidson, Raymond John January 1993 (has links)
The thesis takes the form of a collection of publications and patents concerning gold extraction which were presented over a period of 18 years while employed at the Anglo American Research Laboratories.

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