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The Amacan Copper Project was constructed in the Philippines by a Finnish-Filipino Consortium during the years 1979 - 1982. The project involved a turnkey contract for a mine and a concentrator to process 25 000 tonne per day of porphy- ritic copper ore at a grade of 0.45% Cu. The orebody is located on Mindanao, the southernmost island of the Philippines, in rugged, mountainous terrain approximately 1 000 m above sea level. The adopted design principle was based on an efficient, straightforward installation utilising a minimum number of items of equipment each with high unit capacities. The consortium faced many problems which resulted in lengthy delays in construction and finally led to the client taking over responsibility for the completion of the project. The concentrator was successfully commissioned in July 1982.

Jan 1, 1986

By Riley S. J

Ranger Uranium Mine is located within the Alligator Rivers Region of the Northern Territory of Australia and surrounded by the World Heritage listed Kakadu National Park (Figure 1). The mining operation is currently producing about 1500 tonnes of uranium oxide annually, as well as considerable volumes of waste rock, low grade ore and tailings. The rehabilitation of the project should ensure that the radioactive mill tailings and other contaminants remain contained for at least 200 years, as required by the existing guidelines (Commonwealth of Australia, 1987). The present uranium mining operation is regulated by the Northern Territory Department of Mines and Energy who must refer to the Environmental Requirements when considering regulatory options. These Environmental Requirements were agreed by the

Jan 1, 1994

At Yucca Mountain, USA, a tunnel is being built according to nuclear quality standards. It has proved possible to meet very high quality demands while at the same time achieving high advance rates. To be able to do this, routines on how to record and store quality related information have been established. This has meant that a new philosophy has entered the tunnelling industry. Especially for nuclear waste projects, of which Yucca Mountain is one of the first ones to be built, the experiences made and the quality assurance program established will be of great importance for future projects. The paper gives examples of what the Nuclear Quality Assurance system has meant in practice for the tunnelling at Yucca Mountain. And, it also explains why a non-grouted bolt, Super Swellex-, was chosen for long-term reinforcement in the tunnels which might host nuclear waste for thousands of years.

Jan 1, 1999

The distribution of p(~rphyt1 copper deposits, in time as well as place, is used to propose an occurrence model based on the genesis models of Sillitoe and Rona. A magmatic source of the metals is accepted. The characteristic metallogenic epoch and the migration of the mineralization event along an elongate metal province are explained as the result of subduction of an obliquely- oriented strip of mineral-enriched material on the oceanic plate. Two mineral-enriched trails emanate from a hot-spot source of high-intensity hydrothermal activity in an oceanic rift. Because the whole plate system moves relative to hot spots, the hydrothermal source appears to migrate along the rift, and the two trails are not parallel to transform faults, but form a broad "V" centred on the hotspot. Source loci are spaced at intervals of about 3000 km, resulting in the possible repetition of metallogenic epochs, in a subduction zone province, at about 100 m.y. intervals. The position of the mineral-enriched strip can be found graphically, given ages of a series of deposits in a province, and the plate convergence vectors. This knowledge provides an exploration tool at regional scale and, by reflection across the rift, the potential for exploration is extended across oceans. The model has implications for commodities and deposit types other than porphyry coppers.

Jan 1, 1987

By Enever J, Walton R, Wold M

Photoelastic and equivalent material model ling techniques for studying stresses and defor- mations and modes of failure in geological and engineering structures are described. The appli- cation of these techniques to the solution of tunnelling design problems is outlined. Models may contain heterogeneous components to simulate geological and man-made structures and may be two- or three-dimensional. Prototype construc- tion procedures and time dependent behaviour may be modelled. Examples of recent model studies carried out for the design of underground railway tunnels are given. Development of photoelastic and equi- valent material modelling techniques and facili- ties at the CSIRO, Division of Applied Geomech- anics are described, including a biaxial and triaxial frame for testing large scale two and three dimensional equivalent material models and components of full scale prototype structures.

Jan 1, 1976

By Luke K. A

Pressure on production at New Zealand China Clays has led to the development of a dewatering control loop for fine halloysite china clay. The development was based on the analysis of data from the automation of plate and frame filter presses. The analysis of the data has led to process changes, and the ability to quickly solve dewatering problems. As a result of control in the dewatering circuit press times have reduced on average 117% and output has increased proportionally.

Jan 1, 1989

By R Loweth

The application of discreet event simulation has matured in modelling manufacturing systems for production analysis. This simulation tool was used in studying a number of mining operations, especially material handling processes. The study of truck-shovel operation including equipment matching, selection, and production estimation utilised the discrete event simulation for providing valuable decision-making information. The sophistication of the available simulation tools grew over times, and simulation driven animation was used to facilitate the validation and visualisation of the simulated system. This form of visualisation enhanced the simulation use greatly. First of all, it provided a communication medium to transfer information to the non-technical managerial personnel as a better decision-making tool. Moreover, the animated visualisation provided a validation tool to check the working of the simulated system and interaction among its components.

Jan 1, 2003

By Barns K. E, Munro P. D, Brindley S. K

Ernest Henry Mining Pty Ltd started production in August 1997. The Ernest Henry orebody consists of two distinct parts, a complex supergene ore zone overlying a primary ore zone. The economic copper minerals in the supergene ore are chalcocite

Jan 1, 1998

Ore petrology will fundamentally determine the types of metallurgical processes employed for ore treatment, their operational efficiency and the nature of processing problems encountered. It is therefore paramount that the petrological charact

Jan 1, 1998

By Mountiney B

The development and operation of three large open cut brown coal mines in the Latrobe Valley, Victoria, Australia, requires a wide range of drilling techniques for coal resource evaluation and stratigraphic defi- nition, material property identification, open cut dewatering, and instal- lation of groundwater monitoring bores. This paper describes in detail the range of drilling techniques, equip- ment used and associated problems with drilling, in a deep sedimentary basin containing several major brown coal seams, multiple aquifer sys- tems of varying pressures and thin layers of hard materials including pyrite, siderite and basalt. Methods of rotary drilling include wireline core drilling, conventional core drilling, conventional flush drilling, diamond core drilling, reverse circulation air lift drilling and bucket auger drilling. Cable tool drilling is also used for strata definition and aquifer sampling.

Jan 1, 1989

By Sharma T

Laboratory investigations have been carried out on direct leaching of lead-zinc complex sulphide ore and zinc concentrate using ferric chloride. From the investigation it was observed that the use of 0.15 M and 2 M FeC13 gave an optimum dissolution of metal ions from ore and concentrate respectively. The kinetic studies conducted showed that the leaching reaction followed a shrinking core model for galena and sphalerite. The presence of impurities such as pyrite had increased the dissolution rate and reduced the consumption of ferric chloride. Further, the studies were conducted to recover dissolved zinc from the chloride solution by selectively precipitating it as zinc ammonium chloride.

Jan 1, 1992

By Kyle J. H, Misra V. N

The recovery of copper from a flotation concentrate using ferric chloride leaching has been investigated. The concentrate from the Horseshoe Lights Mine near Meekatharra, Western Australia, contained mainly digenite, pyrite and talc minerals. Over 95 per cent of the copper was dissolved in an acidified ferric chloride solution in one hour at 70¦C and ambient pressure. The pyrite and gangue minerals did not react. The leaching process was found to consist of four separate reactions and the shrinking core model was used to describe the process. The effects of particle size, temperature, concentration of FeCls, stirring speed and leaching time on metal dissolution were investigated. The apparent activation energies in the second, third and fourth reactions of leaching of copper concentrate were 28.8, 11.9 and 53.9 kJ/mol, respectively. The optimum conditions for the leaching of copper from the concentrate, within the range of conditions studied were: particle size 63 per cent minus 38 ¦m, a ferric chloride concentration of 1.48 M, a temperature of 70¦C, and a stirring speed of 800 rpm.

Jan 1, 1991

By Smith JW

Studies of 13C/12C ratios of carbon dioxide in seam gases and in secondary calcites show that 1. In mines prone to carbon dioxide outbursting, the source of this gas is external to the coal. 2. Faults draining reservoirs of magmatic or primary carbon dioxide, rather than intrusives, are the most likely points of entry of carbon dioxide into mines. 3. The higher the concentration of carbon dioxide in seam gas and the wetter the mine, the lower the likelihood of secondary calcite occurring as a filling in cleats, fractures etc. 4. A -role played by carbon dioxide in promoting outbursting may be the conversion of calcite to soluble bicarbonate, the removal of this in mine water and the subsequent weakening of the resistance of the bulk coal to stress.

Jan 1, 1980

By Patridge A. C

Hydrocyclones have widespread use as classifiers in applications such as mine fill preparation and coal preparation. A fundamental conflict often exists between recovery of all of the valuable material and maintaining the quality of the product. This conflict is a result of a portion of the feed material passing through the cyclone, effectively without undergoing any classification. This paper describes an investigation, undertaken as an undergraduate project in mining engineering at the University of NSW (Brook, 1994), into aspects of cyclones in which supplementary water injection is used in an attempt to reduce the amount of misplaced fine material reporting to the coarse product and hence improve the overall classification efficiency. In particular, the study concentrated on the effects of different modes of water injection. Two methods of introducing wash water into the cyclone body were investigated. A series of tests were performed on a laboratory hydrocyclone having provision for radial water injection at different levels through small orifices in the wall of the conical section, and a preliminary study was made of the performance of a novel cyclone in which the conical section had walls of a permeable polyethylene, permitting a uniform introduction of wash water over the entire surface.

Jan 1, 1995

By Mutton B. K

A systematic approach to the collection, presentation and application of structural geology data is employed in the extraction of narrow en echelon Ag-Pb-Zn orebodies by rut and fill stoping at Mount Isa. The aim is to locate, document and predict areas of adverse ground thereby enabling adequate ground support to be installed in advance of production mining. The important structural features are identified and their relevance illustrated by case histories of previous failures. The methods of collection, documentation and application of data are discussed.

Jan 1, 1977

The, Ore-bodies.-The ore-bodies of the North mine, North Broken Hill Ltd.; consist of two lenses, connected by a narrow neck of mineralized country. They pitch at an angle of 40° in an easterly direction and dip north at 60° to the horizontal. The southern ore-body, on a horizontal plane, has a total maximum length of 800 feet and in one place attains a width of 230 feet, whilst the northern orebody has a maximum'length of 600 feet and a maximum width of 80 feet.

Jan 1, 1940

The mine planning and operational aspects of applying Continuous Surface Miner (CSM) technology to Australian coal strip and open cut mines is investigated for both existing and planned deposits. CSM produc- tivity as a function of geomechanical properties, formation thickness, mechanical availability and in-pit physical constraints, are considered. Productivity and operational costs are derived from current production machines and from first principles.

Jan 1, 1989

The maintenance system for underground mobile equipment at Cobar Mines Pty. Ltd. has been modified from that originally planned as a result of experience gained in operating the equipment.Downtime due to breakdowns has been reduced by improvement of vehicle servicing and overhaul procedures.Frequency of breakdowns can be reduced by training operating and maintenance personnel to a high standard, ensuring adequate numbers of tradesmen and supervisors, good maintenance facilities and communications, a well designed mine layout, and a comprehensive stock of spare parts.A maintenance and downtime summary is compiled for each four-week operating period and this is useful in highlighting particular problems where corrective action must be taken.

Jan 1, 1969

By S Pigram, G J. Jameson

This paper is concerned with the tracking of particles in the froth phase of an aerated water/glycerol mixture. Experiments have been carried out in a specially designed laboratory flotation cell that allows formation of a deep froth. Phosphorescent tracer particles of various sizes were injected into the centre of a froth column where they were excited by ultraviolet lights, positioned at the back and front of the column. The motion of particles was captured on a digital camera with a green filter. The images from the digital camera were then transferred to a computer and an image analysis program was used to convert the colour intensity to the concentration of particles at each location within the froth. The tracer technique was used to determine the dispersion of hydrophilic particles and the variation of the concentration of solids with axial and radial positions.

Jan 1, 2005

By Denholm W. T, Rankin W. J

The reduction of zinc from lead blast furnace slags using hydrogen was studied at 1300¦C as part of a laboratory investigation of zinc fuming. To perform the experiments, 300 g "spent slag" was melted in a crucible. Hydrogen was then injected into the slag through a lance and fresh blast furnace slag was added regularly in small quantities over a period of 40 minutes. Zinc added in the fresh slag was reduced and the zinc level of the bulk slag attained a steady state value of between 1 and 9% after about 10 minutes, depending on the gas injection rate. Because of the high reactivity of hydrogen, bulk supply of hydrogen to the slag was the rate limiting step at the flow rates used and it is believed that the gas-slag reactions in the system were at equilibrium. A partially/stabilized zirconia cell with a Ni/NiO reference electrode was immersed in the slags during the experiments and the steady/state oxygen potentials of the slags were measured. By using the experimental oxygen potential values and calculated values of the steady state concentrations of zinc in the offgas, the activity of ZnO in the slags was calculated from the Gibbs's free energy change for the reaction:

Jan 1, 1989