The deep seabed until the late sixties was a largely unknown part of the sea and represented nothing more than an academic curiosity. With technology making hitherto hidden depths of the ocean accessible for exploitation, it became known in the late sixties that the deep seabed contained precious minerals. In a world used to shrinking resources, this shot the deep seabed into the centre stage of world politics, becoming perhaps the most controversial issue in any United Nations Conference. The controversy centered around the legal status of the deep seabed. This work contends that there is not in place any viable international legal regime for supervising and regulating resource development in the deep seabed outside national jurisdiction; that whatever regulations there are, are geared towards facilitating exploitation of the area; that such lacunae would be at an environmental cost that could negate whatever short-term benefits are derivable therefrom. / This work therefore examines the potential environmental impact of deep seabed mining and proposes a legal regime for preventing and minimizing same.

Few rotary blasthole drills presently used in open pit mines are equipped with automatic control systems. Those drilling control systems which do exist are based mainly on ladder programming techniques. This thesis is an investigation into a closed loop feedback control approach for drilling control. / A model for the plant consisting of the machine's actuators and the drilling process at the bit-rock interface is described based on physical assumptions and past research in this area. The model equations are further refined by experimental (field) testing. The instrumentation of a TAMROCK-DRILTECH D75K drill rig and the subsequent drilling tests aimed at refining the model equations are described, with an in-depth discussion of the field tests results. The analysis is based on regression techniques applied to empirical data, showing the dependencies between the cutting variables and ground conditions during actual drilling. The transfer functions of the mechanical actuators of the machine are also identified. / A strategy for automatic feed pressure control is proposed and developed as a software source code. The controller is tested and tuned by interfacing it to a software simulator of the plant which implements the relationships identified from field testing. The simulation results are discussed. They show that the proposed strategy is viable: however, it is subject to some limitations. / The thesis concludes with suggestions for future research and improvement of the proposed control approach.

This research documents the use of a 7.6 cm laboratory Knelson Concentrator (LKC) to determine the amount of gravity recoverable gold (GRG) content in ores and evaluate the performance of gravity circuits, with an emphasis on high gangue density. Two approaches were used to minimize the effect of the high gangue density in estimating the GRG content, oversize removal and 2:1 ratio dilution with silica flour. / The amount of GRG was determined in four ore samples with an established protocol, yielding values of 35% to 78% of total gold. / Results from the Angnico-Eagle La Ronde Division (AELRD), Louvicourt and East Malartic mills suggest that the typical Knelson-based gravity circuit which can recover one half to two thirds of GRG from low density gangues will only recover one third to two fifths of the GRG from high density gangues. Simulation of gold recovery at AELRD showed that the high circulating loads, 700--1100%, were a significant factor in reducing gold recovery by gravity. (Abstract shortened by UMI.)

The purpose of this study is to develop a micro computer-based dispatching system to assist mine operators in choosing the optimal truck assignment under a set of given conditions. The system is active, semi-automated and includes procedures to suggest to the dispatcher the best truck allocation with the aim of reaching a specified production objective. / New heuristic dispatching procedures, namely Adjusted Travel Empty and Load Time, Adjusted Cycle Time, Adjusted Cycle and Waiting Times and Minimize Cycle Time have been developed in order to consider the achievement of objectives throughout the working shift. These procedures are tested and compared with the fundamental heuristic procedures; Locked-in, Maximize Truck Use, Maximize Shovel Use, Match Factor and Priority Number. The heuristic procedures do not attempt to optimize the decision but produce acceptable results most of the time. / For the purpose of testing the new heuristic dispatching procedures a computer simulation program was designed. This program resembles as much as possible the real production process. An advance-clock approach was selected to allow insertion of procedures at any point in the haulage cycle. / It was found that truck dispatching systems offer the potential for significant improvements in productivity. The new procedures are also able to consider production objectives. However each mine must evaluate each dispatching procedure independently before a definitive decision is made.

This thesis deals with the appraisal of the economics of underground conversion in surface limestone mining operations. Software that predicts the time at which an open pit operation should be converted to underground extraction has been developed. The software is based on estimates of capital expenditures required for the underground conversion and for future equipment acquisitions and replacements under both open pit and underground operating alternatives, as well as long-term operating cost estimates for both alternatives. Open pit and underground cost estimates can be entered either directly, or estimated using O'Hara and Suboleski's (1992) cost estimation equations. It is assumed that an underground source of limestone is accessible and that its extraction is technically feasible. The program determines the cost-flow profile of each alternative and compares their present worth equivalents at yearly intervals over a pre-determined period of analysis. The program reports the optimum time for the conversion, if indeed it exists. / The report starts with a review of limestone and dolomite as mineral commodities. This is followed by a brief literature review relating to underground conversion of surface mining operations. Mining methods and costs related to industrial minerals are then described and discussed. The thesis concludes with a detailed description of the software and a hypothetical case study.

Mining automation has incrementally progressed from line-of-sight remote operation to teleoperation and automatic control of mobile machines, mainly due to significant advances in underground communication systems. The present trend points towards a robotic mining environment where mobile machinery and stationary equipment will be fully integrated with a mine-wide information system overseeing all aspects of mining via a communication network. The successful design and implementation of the software and hardware components necessary to realize this vision depends on the level of seamless integration achieved. The complexity involved in terms of systems functionality and coherence necessitates systems analysis and computer-aided software engineering tools to actively support this integration effort. / Hence, the primary objective of this thesis is to introduce and relate systems analysis concepts and tools to the business of mining. This investigation begins by setting the industrial context of this work with respect to past initiatives and future trends. It discusses different approaches to the design and implementation of mining information systems. It reviews the fundamentals of software and information engineering as well as structured and object-oriented analysis and design. It presents a survey of computerized tools for systems analysis. It then applies systems analysis concepts and tools to a high-level top-down analysis of a Mine Information System and examines a specific mining process in detail. Finally, it compares the applicability of structured versus object-oriented analysis and design methodologies to the complex problem of mining.

A novel digital image analysis technique to measure the size of fragments on the surface of a muck-pile is presented in this thesis. The technique takes into consideration the physical characteristics of fragment representation and measurement problems. Using an adaptive smoothing filter prior to edge detection, each fragment on the surface is represented by a group of edge segments outlining its boundaries. These segments are then grouped to form continuous contours. / A multi-layer analysis of the digital image is then formulated where fragments on the surface are grouped into three layers, each of which is categorized by global characteristics and is related to other neighbouring layers by local characteristics. These local relationships between the layers are used to approximate the missing parts of the fragment contour. / An extensive analysis of the sieving process is used in building the relationship between the shape and the size of individual fragments. Using this relation, a new multivariable measure for each fragment is developed. These measures are used in estimating the size distribution of the muck-pile and compared with other existing measurement techniques. This comparison proves the robustness of the technique developed in this thesis.

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