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By Kim M

Mukuk gold mine in South Korea produces a pyrite concentrate containing gold associated with arsenopyrite as a gangue mineral. The effects of Portland cement as a depressant on the flotability of arsenopyrite were studied to improve the separation of arsenopyrite from pyrite concentrate containing gold. A series of the fundamental flotation tests were performed using Portland cement as a function of pH and concentration of the collector. Flotation recovery of pyrite and arsenopyrite in the fundamental tests with amyl xanthate showed that arsenopyrite was depressed by the addition of a moderate amount of Portland cement, but pyrite was not depressed by it. In the flotation tests of the artificial mixture samples with arsenopyrite and pyrite, following pH were adjusted to be 10.5 by Portland cement, different amount of amyl xanthate was added. The results from these studies showed that flotation recovery of pyrite was 100 per cent under the condition of some addition of amyl xanthate, but arsenopyrite was not floating at all. Portland cement shows remarkable depression of galena, but its effect on the flotability of chalcopyrite is not as clear. In the pulp under Portland cement addition, chalcopyrite can be easily activated by the addition of sodium bisulphite, whereas galena is depressed more effectively. From the batch flotation tests with the pyrite concentrate, the galena concentrate and the Cu-Pb bulk concentrate from the mines, it was confirmed that the results of the batch flotation tests agree with the results of the fundamental flotation tests. The effects of depression by Portland cement on pyrrhotite, marmatite and stibnite are also discussed briefly.

Jan 1, 1993

While sampling techniques used by the mineral industry continue to improve, sampling is still an area which is often neglected. It is often left to personnel who do not fully appreciate the significance and importance of sampling. Yet sampling and sample processing are of vital importance. There is little point in making major capital investments in the latest analytical equipment and spending considerable time obtaining the best analytical precision, if the sample provided for analysis is seriously biased in the first place.

Jan 1, 1976

Future depth and production limitations of an ore hoisting system are fixed by its initial design criteria. There is little scope to extend these limitations once installation is completed. Depth and production rate upgrades from the initial duty to the hoistÆs practical limitations require capital expenditure in stages, each of which can be defined when assessing the initial system design criteria. A means of presenting and assessing the design criteria, the limiting factors in each option and the relative present and future capital costs is necessary to arrive at a solution that delivers the best value to the mine. Application of this technique to recent friction winder installations and upgrades in the Australian mining industry is of particular interest; however, the analysis methods are also applicable to drum hoists. It is usual to specify a minimum hoisting capacity and depth, based on mine ore handling design and production needs. The final hoist depth and production rate are usually a result of the initial hoist design and hence it is useful from the outset to specify a required production versus depth envelope for the mine. Technical solutions can then be modelled within this envelope at their initial and final duties and a comparative analysis made against the cost of installing and progressively upgrading each solution. Understanding the factors that constrain each solution to a maximum production rate at a given depth is important, as the costs of overcoming limiting parameters such as rope tread pressure and motor power can be significant. The task of understanding and evaluating the options open to the hoisting system designer is simplified using this approach. Communicating the results of a multi-dimensional problem such as hoist specification is also made easier using the graphical methods inherent in the analysis.

Jan 1, 2005

As a basis for my address to you tonight I thought it might be opportune if we considered the great history of the mineral industry in Australia, and the contribution it has made to the development of the country. While it is perhaps interesting to review the achievements of the past there is also the opportunity to examine the developments of the future.The names generally given to the three periods of man's life on the earth-the Stone, the Bronze, and the Iron Ageand to which should perhaps now be added the Atomic Age, imply the vast importance of the progressive steps in 'man's discovery of minerals and the means of working them. They tell the story of his advance from the flint knife to the bronze celt, and then to the keen-edged iron weapon, and now to the possibilities of the peaceful application of atomic energy. Not only have the stories of gold, iron, copper and tin told a great deal of the history of the progress of mankind, but they have also traced the commercial and industrial growth of Australia over the last century.Gold in the 1850's was responsible for the most significant period of immigration Australia has ever had-when the population almost tripled in the ten years to 1860. Minerals were also responsible for opening up Australia and determining the pattern of settlement. As mineral finds were made, railways were constructed to these fields, then agricultural development followed.Then, as the industrial era started, minerals provided the raw material for Australia's rapid industrial expansion, and they have all contributed to the extent that they have made...

Jan 1, 1960

During the last 20 years, manufacturers of Australian iron have given increasing attention to development of external markets for processed blast furnace slag. Slag has been in widespread use overseas and data on the performance of Australian slag in concrete lave shown it is suitable for that use. Chemical and physical properties of typical Australian slag products including air cooled, granulated and pelletised slag are discussed and compared with local natural aggregates. Special attention is given to pumping achieve- ments with slag concretes and the observed durability of concrete after many years service. More'recent applications for granulated slag as a sand replacement are discussed. It is concluded that'whilst more wide- spread use of slag is possible, the cost of marketing and transporting slag are likely to restrict opportunities unless for local usage.

Jan 1, 1979

By Schmidt LC

The method of supporting excavated roofs in underground coal mines by conventional roof bolting systems is challenged due to its shortcomings of being time-consuming and leading to possible unsafe installation. Though a few alternatives have been considered, the ultimate and most efficient bolting method has often been conceived as one using a self-drilling roof bolt, or a Rapid Face Bolting System (RFBS). The on-going Rapid Face Bolting Project undertaken by the University of Wollongong includes a special tubular bolt design.The tubular bolt designed for the RFBS is a "single-pass" bolt equipped with cutting tips used to drill a bolthole to accommodate the bolt. Different from that of the coring bit employed in geological site investigations, the principal design consideration for the tubular bolt is low cost associated with a small working life for the cutting tip.

Jan 1, 1991

Industrial relations on Australian and New Zealand resource projects can be volatile. Therefore investors have become increasingly aware over the years that sound industrial relations during construction is vital to the overall success of their project. There has been a wide range of actual industrial relations performance, project by project, and the degree. of success often directly correlates with the degree and thoroughness of pre-project planning. However, although many projects have been crippled by delays and cost overruns because of labour disputes, good results are achievable. Total commitment to the project by all parties involved is essential and it is up to the employers to seek out this commitment and not just trust mother luck. Industrial relations must be taken very seriously as the price of failure can render a resource project unviable.

Jan 1, 1983

The paper reviews recent valuations of mineral properties, many of which are at an early stage of exploration. The various methods used are outlined. The problem of comparing, in terms of whether it is fair and reasonable, a highly subjective opinion of the present value of a portfolio of exploration tenements with a vendor consideration, the real value of which, in most cases, lies at some indeterminate time in the future because of the application by the Australian Stock Exchange (ASX) of escrow conditions, is highlighted. Examples are given of some of the questionable logic used by consultants in handling this difficult issue. A proposal for revision to current flotation and listing practice which, the author believes, would circumvent the problem and at the same time provide better protection for the investing public is offered for Consideration.

Jan 1, 1994

By Taylor RN

A simple apparatus for delivering pulverized coal as fuel to a SIROSMELT lance is described, and its performance in smelting tests is evaluated. Using the pulverized coal as fuel, the SIROSMELT furnace performed well in both oxidative copper smelting and reductive smelting (zinc fuming). In both cases the evidence suggests that part of the combustion occurred by indirect oxidation of coal particles entrained in the bath. Oxygen potential measurements made during the zinc fuming tests confirmed the general features of the the non-equilibrium mechanism for zinc fuming proposed by Richards and Brimacombe. The zinc level in the slag during continuous fuming was lower than was predicted using an equilibrium model.

Jan 1, 1987

As mines become deeper, the problems of heat in the workplacebecome more acute. An important response from the industry hasbeen the widespread adoption of microclimate cooling such asair-conditioned cabins. However, not all work in mines can becompleted from inside an air-conditioned cabin, and in any event,it is still important to keep the ambient air in the mine outside ofany microclimate to a safe temperature. An important method forbringing workplace temperatures under control is the appropriateuse of refrigeration. The application of refrigeration inmechanised mines has been recently described (Brake, 2001;Brake and Fulker, 2000). This paper provides an overview ofsome of the important engineering considerations in thespecification and selection of mine refrigeration plants. Thepurpose is to provide a basic understanding of refrigerationprinciples, practices, terminology, hazards and opportunities formining engineers or other personnel who may need to beinvolved in the introduction of refrigeration onto a mine site.

Jan 1, 2001

Ion exchange resins are an attractive alternative to activated carbon in both column and resin-in-pulp processes for the recovery of gold from cyanide solution. Resins are widely used for this purpose in the Soviet Union apparently in preference to activated carbons.A wide range of resins are available and the high level of resin technology is demon-strated in the resin processes used to recover uranium.The anionic gold complex, Au(CN) 2 , is selectively adsorbed onto weak and strong base resins. However other anionic cyanide complexes, cyanide ions and other anions from the process water are also adsorbed onto resin sites. Resin selectively for gold is not as high as it is for activated carbons. As a result similar gold loading capacities are obtained for resins and carbons when used in plant liquors.

Jan 1, 1984

In Munich's peculiar hydrogeological conditions (water bearing sand strata between layers of impermeable clay, silt or marl) are proper functioning groundwater lowering methods of decisive importance for underground construc- tion. Shield tunnelling with compressed air has al- ready proved to be successful. In view of growing application of shotcrete tunnelling it was obvious to consider the use of compressed air even here. After a preliminary research-project the first subway section "shotcrete under compressed air" was 1979 awarded in Munich and since that time five sections have been awarded, respectively completed. On the basis of the experiences meanwhile obtained reports will be given stating the frame conditions in which this new construction method can be applied. The tunnels consist of two shells. The outer ist driven by shotcrete under compressed air. In order to keep the air overpressure low, the groundwater often is previously detensioned or partially lowered. The inner shell of watertight concrete is built under atmosperic pressure.

Jan 1, 1987

By McCarthy P. L

With production at Olympic Dam scheduled to commence in June 1988, it has been necessary to install a complete underground ore handling system capable of removing two million tonnes of material annually from the mine. The system comprises mucking from stope drawpoints, truck haulage to underground storage, primary crushing, conveying and hoisting. On the surface, material is conveyed to stockpiles at the Metallurgical Plant. Mining of the numerous special excavations within the system was incorporated into the mine's ongoing development program prior to the underground construction phase. Utilisation of a decline from the surface enabled versatile construction equipment to operate at the underground sites as well as simplifying the transportation and delivery of construction Materials.

Jan 1, 1988

The provision of electrical power is an important consideration in project develop- ment. The first step to be taken in this area is to assess the power requirements of the project. The alternatives of taking a supply from a power authority or providing local generation can then be considered. This requires additional definition of the prob- able characteristics of the supply. The availability of authority power in Australia is limited by the extent of the state power grids. Recent developments now allow these grids to be extended and their load capacity increased to meet major load increases at less cost than was possible pre- viously. The options for local generation include diesel, gas turbine, steam, hydro, solar and wind, each having its particular performance characteristics and costs. The choice of fuel for diesel, gas turbine, and steam plant likewise involves consideration of a range of factors. The arrangements adopted for a number of development projects illustrate some of the aspects which influence the decisions on power supply.

Jan 1, 1986

Mining of the silver-lead-zinc orebodies at the George Fisher Mine officially started in 2000. A review of mining performance to date shows that many of the extracted primary stopes have experienced some degree of hangingwall dilution. The degree of hangingwall failure in the stopes became progressively more extensive throughout mining of the orebodies in 2001 and 2002, culminating in the unplanned catastrophic failure of the 744D stope in which the ore between 13C (2683RL) and 12L (2714RL) sublevels caved into the previously mined cavity between 13L (2654RL) and 13C sublevels. This was followed several months later by another unplanned caving event in a nearby stope, 740D. As a direct result of these unplanned failures it was decided to mine the stopes with a smaller span than had been previously planned and in a primary-secondary pyramidal stoping sequence. To limit the exposure of the stope hangingwall, a hangingwall drive is no longer developed and therefore geologists no longer have access to the detailed geological information that this provided. Geologists at George Fisher Mine have had to be adaptable and flexible in response to these proposed changes and rely more on data from drilling than mapping for their geological interpretation. The result is that the drilling cycle has become much more critical in the planning process.

Jan 1, 2003

A simple method of designing effective fill drainage systems for slurry backfill is presented. By using the proposed method, it is easy to calculate and predict the expected fill drainage rates or to provide additional drainage systems to accelerate the fill drainage. The fundamentals of hydraulic fill and an efficient method to determine its permeability is also explained. The safety in hydraulic filling and bulkhead stability depends totally on achieving effective drainage regime for the fill. This paper provides the basis for creating such efficient drainage regimes. The recent fatal fill bulkhead failures in Australia were the result of poor drainage from the respective fill masses, and therefore it is more important to provide suitable drainage arrangements to continue using hydraulic fill to the benefit of the mining industry. At present there is no procedure available to mine operators to estimate the expected bulkhead pressures to design a satisfactory bulkhead. Some mines are constructing bulkheads after their initial investigations carried out years ago. Other mines have simply borrowed the ideas from the pioneer mines and using in their areas. It is high time that we develop a rational approach to estimate the expected bulkhead pressures for the design of bulkheads. We need a simple model that could be understood and used by the mine operators on a day-to-day basis. This paper also presents a model to predict the bulkhead pressures for designing safe bulkheads.

Jan 1, 2002

I take it the character of addresses to conventions, should, following precedent, avoid details, and treat subjects rather from a philosophical point of view so far as they will permit.In the subject about to be treated on, an endeavour will be made to find here we stand as regards the past, in order that we may the better, hope to look correctly in the direction to be followed.It may be assumed that the main object of the Institute is to forward mining interests and the ways in which engineers can aid those interests are many. If all of us were to try to follow many of those interests we should become like" jacks of all trades and masters of none". Mining engineering is consequently subdivided, all are necessary to the common end, and it is on one of those divisions I have undertaken to address you. The subject or steam pumping is a large one, and I regret, not having received such longer notice as would have enabled me to do better justice to the subject, and more respectful regard for yourselves. I must, however, under the circumstances, crave your generous consideration, and hope the topics mentioned may furnish material for discussion and future papers of far more value than this one, Ind.eed, the subject is so illtimately and historically associated with mining that if treated on its merits would be highly interesting or could be made so in more capable hands.

By Misk A

Several logging methods are presently available to the oil industry for the evaluation of formation porosity: the Sonic and Neutron logs are already widely used, the Gamma-Ganmia log is being progressively introduced. The readings of these instruments are primarily a function of the rack-porosity, hence the general term of "porosity tools". Apart from porosity, however, other variables such as type of fluid in the pores, nature of matrix and degree of shaliness have an important influence.The response of each device is a different function of such parameters: therefore, a cci bination of porosity tools can lead to information on these variables in addition to the evaluation of effective porosity.For example, the presence of gas; rather than water or oil, in a formation which is not deeply invaded, will tend to give Neutron derived porosity values which are too 'low; on the other hand, the Sonic derived porosity: value will be too high in such- a case. For the same porosity, the Sonic gives a longer transit time in sandstone than limestone, whereas in the low porosity range, the Neutron will read more counts per second in a sandstone than in a limestone of the same porosity. The presence of shale also affects the readings of the various porosity tools in different ways so that the combination of two or more methods may lead, in some cases; to an evaluation of both the-effective porosity and the shale, content.In conclusion, it may be said that the various porosity tools pre-sently available, are, to a large extent, complementary, and that in many problems the use of two porosity tools, instead of one, is very likely to bring valuable additional information.

Jan 1, 1962

Here, in what is partly a review and partly a personal viewpoint, I take stock of changes in emphasis and comprehension on the subject of basaltic volcanism in the decade that has passed since the completion of the landmark Basaltic Volcanism Study Project (1981). I concentrate attention on the relatively neglected physical-volcanology aspects (in 1988 it was still possible to publish a 340-page book on flood basalts with barely any mention of physical mechanisms).I adopt the useful unifying concept of "volcanic system" to embrace the invariably-present intrusions as well as the volcano; I consider controls exercised by magma-supply rate and modulator-mechanisms on the nature of the system;I emphasize that sheeted-intrusion complexes, consisting either of dikes or inclined sheets (depending on the ability of the system to expand laterally) occur in all eroded major systems and fuel geothermal systems; I show how constraints set by cooling of narrow intrusions cause such complexes to be wedge-like and produce considerable rotations; I consider the role of the level of neutral buoyancy in making magma chambers possible, causing lateral subsurface magma flow and localizing intrusions, while the LNB itself can be accentuated by intrusions; and I examine the possibility that underwater systems could have very different internal structures from systems on land.

Jan 1, 1990

With the exeption of the United States, Canada and Russia, oil has not been around in quantity near world centres of population. Production: in Western Europe is insignificant. Japan is without production as are Australia, Southern Africa, India; Brazil, Chile, New Zealand and China. The United States is, however, a large importer of crude oil. The very fact that oil is produced generally away from centres of population means that it has to be carried by sea to the area in which it is required. There is, therefore, a constant flow of oil around the world in very definite channels.

Jan 1, 1962