Search Documents

By Clark K. N

The need for and advantages of simulators in iron ore pellet induration research are described. The approaches to simulation and the techniques to carry it out are discussed in detail covering drying and firing for the straight grate process. The CSIRO simulator design is described and some errors in simulation are discussed.

Jan 1, 1974

By Borkin AD, Yemelyanov MF, Otrozhdennova LA, Malinovskaya ND, Nechay LA, Koltunova TY

The results of investigations of reagent regimes and flotation machines to decrease the losses of valuable components in both coarse and fine particle classes during non-ferrous metal dressing are considered.

Jan 1, 1993

Two separate mine rehabilitation programmes carried out by Australian Consolidated Industries Limited (A.C.I.) in South Australia at Normanville and Port Lawler are discussed. Emphasis is given to the methods used, the results achieved and to possible future improvements.

Jan 1, 1976

Platinum Group metals have been known in New Zealand since the 1880's but not produced on a large scale. They have been neglected because their value was not appreciated rela- tive to gold and their value was often very low, reflecting demand, and because recovery was difficult compared with recovery of gold. With the rising price of most Platinum Group metals and the perfection of gravity and flota- tion recovery methods, recovery of platinum along with gold from alluvial deposits is more attractive. Platinum Group metals are known in several different environments in New Zealand, ranging from alluvial placer deposits to layered basic to ultrabasic intrusions and quartz veins. None of the known occurrences have been ade- quately prospected and there is a real possibi- lity of future discovery of important deposits. Several New Zealand based and at least two offshore resource companies are currently involved in exploration, prospecting or mining for Platinum Group metals in New Zealand.

Jan 1, 1987

The Northland Peninsula of northern North Island, New Zealand contains a complex and diverse record of volcanism which reflects rapid tectonic changes during the late Cenozoic. The main volcanic associations observed on the peninsula are late Cretaceous- early oceanic crust obducted onto Northland at the end of the Oligocene, Miocene arc-type rocks and Pliocene-Quaternary intraplate basalts. This sucession of volcanic successions can be related to tectonic convergence developing into subduction and followed by a an environment of tectonic tension. While the volcanic activity is ultimately linked to specific tectonic regimes, because of rapid change magmatism was decoupled from the specific tectonic event. This decoupling of magmatism and tectonism appears to be a feature of the zones of plate interaction in the southwest Pacific region.

Jan 1, 1990

By Coxhead B. A, Brandt B. A

The geological exploration and evaluation of coal reserves involves the appraisal of very large amounts of data. Computers afford an ideal means of handling and manipulating the data, thereby avoiding the laborious and expensive method of manually compiling the logs in full descriptive language. The Minad system of computer storage and retrieval of geological and analytical data is particularly suited to the description of cores and cuttings from exploration drill-holes. The encoded data is arranged in a 120-column computer output sheet format; descriptive geological information in a 54-column geolog and analytical information in a 64-column assaylog. The acquired data is quantitative, uniform and relatively complete and can be selectively retrieved for processing by a wide range of specialized computer programs developed for the coal mining industry. Visual retrieval of data for manual processing is facilitated by the use of simple codes and logical word abbreviations.

Jan 1, 1977

By Hayward P. G

Complex ores, characterised by intimate intergrowths between minerals, have previously been treated by flotation with limited success. The most common problem has been that the liberation size is often finer than the lower size limit for selection flotation. A technique has been developed in which the problem is overcome by the use of a selective agglomeration procedure in which the values are coalesced with oil to a size suitable for flotation prior to introduction into the flotation machine. A complex lead ore was characterised by QEM*SEM mineralogy as having a mean galena liberation size of 15 ¦m. The best recovery of lead at 50 per cent Pb grade by standard flotation was 53 per cent. After application of the procedure, 86 per cent recovery was obtained after a single cleaner step. The oil functions as a bridging liquid in the presence of conventional collectors which render the mineral oleophillic.

Jan 1, 1991

The introduction ofa submerged entry tundish nozzle incorporating a cylindrical internal space for argon distribution to its inner bore slab is described. In co-operation with the refractory supplier, four major phases of nozzle development have been undertaken. Problems as well as successes are outlined.Significant reduction in alumina clogging ofnozzles has been achieved along with a decrease in nozzle consumption, using resin bonded alumina graphite with up to 4 different materials "zoned" to give resistance to thermal shock, gas leakage, and erosion.

Jan 1, 1985

By R Dimitrakopoulos

The development of mineral resources is based on a spatial model of the orebody that is only partly known from exploration drilling and associated geological interpretations. As a result, orebody models generated from the available information are uncertain and may require the use of stochastic conditional simulation techniques. Multiple-point methods have been developed for petroleum reservoir modelling, enabling reproduction of complex geological geometries. This paper considers a multiple-point approach to capture the uncertainty of the lithological model. The implementation of the method at the Yandi channel iron ore deposit in Western Australia and performance characteristics are discussed. The uncertain lithological model translates into considerable grade-tonnage uncertainty.

Jan 1, 2007

By Durucan S

Uncertainty due to spatial and temporal variability of different pollutants found in soil, water and air is an important issue in the modelling of environmental impacts. Recognition of spatial environmental patterns is relatively straightforward to achieve by applying most of the well-known artificial neural networks or adopting a stochastic approach. However, it is the temporal component of the environmental variables that makes modelling of the environmental pollutants particularly complicated and challenging. This paper presents the results of a case study investigating the artificial neural network performance when modelling the spatio-temporal behaviour of environmental pollutants. The test case involved the modelling and prediction of the distribution of water quality indicators along a river from the point of discharge of treated mine effluents. The behaviour of river water quality indicators is rather complex and shows a lot of fluctuations due to a number of hydrochemical, hydrobiological and hydrodynamic factors. Results obtained in this study indicate that artificial neural networks provide a very powerful and robust method for simultaneous modelling of spatio-temporal behaviour of environmental pollutants.

Jan 1, 1995

By Patridge A. C

A pilot scale laboratory investigation of manual slurry sampling methods representative of those used in the minerals industry is described. Samples were taken from slurries made up from silica particles of various sizes and in various concentrations from a stirred tank and from the discharge lip of a rectangular launder. Sampling methods from the tank included immersion flasks and several configurations of a suction probe. The launder was sampled using a conventional narrow-mouth ladle and also with a 'mouth organ' stream splitter. Samples were analysed for overall solids concentration and size distribution and showed different but always significant and often large biases relative to the known overall composition of the slurry, the nature and extent of bias being dependent on pulp concentration, particle size, sampling method and sampling location. Results clearly show the very great difficulty of obtaining representative samples by simple sampling techniques, although the data suggest that errors can be reduced by using an appropriately designed and operated suction probe. Further work will be carried out with the objective of establishing guidelines for industrial sampling practice.

Jan 1, 1995

Detailed observations were made for two existing continuous miner and shuttlecar systems. A simple model for the shift average cycle consisted of three time components - delays, mining and transport. Cycle improvement and productivity improvement factors are derived and used to predict the theoretical improvement which the observed cycles could achieve. Various strategies of action ranging from short-term optimisation through to long-term planning for continuous haulage systems are evaluated. High potential for improvement is shown for a wide range of operating conditions. An overview is presented for systems, currently available or under active development, which can accept coal directly from continuous miners and offer continuous haulage to the surface. Systems are broadly classified as mechanical-roof mounted, mechanical-floor mounted and hydraulic transportation.

Jan 1, 1982

By M Yahyaei, P Knights, M S. Kizil, J Qu

Digital Twins (DTs) are transforming business operations across many industries through their accurate representations of physical entities enabled by IoT technologies.

Sep 1, 2024

By Haeussler P, Christie A, Bradley D, Skinner D

Mesothermal gold deposits of southern Alaska and Westland, New Zealand have both formed at the seaward edge of major collisional zones in the Pacific basin. In Alaska, production of large fluid volumes correlates in time with the addition of heat into the lower parts of the accreted terranes in the late stages of collisional orogeny. This heat was critical for driving both the metamorphic reactions that released the large volumes of fluid that carried the gold, and the contemporaneous widespread anatexis and magmatism. In Alaska's Chugach terrane, this heat was produced by subduction of a spreading ridge beneath the North America continental margin in the Eocene. The resulting products were the S-type granites and gold-bearing veins. The similar widespread S-type plutonism and gold veining in Westland's Buller terrane suggest that a similar tectonic event could have triggered ore formation along the southeastern edge of Gondwanaland. Based on the Alaskan model, a Devonian or Early Carboniferous age is favoured for high volume metamorphogenic fluid generation and gold vein formation in Westland.

Jan 1, 1995

By Kissell F. N, Volkwein J. C

The U.S. Department of Interior's Bureau of Mines has the opportunity to visit many U.S. mines, including some that claim 2 to 5 times the national average of 334 raw tonnes/unit shift (tps) from a continuous miner section. In a project to assess the reasons for this high production, the Bureau conducted two studies. The first study focused on the 25 highest producing continuous miner sections. What stood out during the visits-was the quality of the labor-management relations. In each of the mines there was a positive labor/management relationship based on mutual trust and a sense that the employees were the company's most valuable resource. Discussions with labor revealed a universally positive attitude toward the company. Interviews with the mine superintendents invariably ranked the quality and attitude of workers as more important than anything else. Also during the mine visits of the 25- mine study, no engineering factors obviously stood out. Time at the face was greater than average, most were in coal over 1.52 m and the roof was generally good. Also, none of the 25 mines had to contend with high methane levels. Because this study found that a high percentage of mines were in seams less than 1.52 m thick, the second study examined thin seam mines only.

Jan 1, 1988

By Granholm S

The current emphasis within the mining industry to reduce the cost of production has stimulated interest in the field of maintenance and operational reliability of capital intensive mining equipuent. The failure consequences of these machines have major safety and economic implications for a mine operator. The reliability centered maintenance (RCM) approach has been found cost effective for equipment maintenance and for achieving high level system perform- ance by many organizations such as airline, military, chemical, process and manufac- turing industries. In this paper an attempt has been made to describe in brief the basic concepts of a RCM approach, the methods of RCM analysis and its cost effectiveness for maintenance of equipment. Since this approach is comparatively new for the mining industry, suitable examples are given to illustrate the case.

Jan 1, 1988

By Manlapig EV, Davis JJ

A methodology for modelling dense medium cyclones is presented for cyclones operating under conditions which avoid particle interference or apex crowding. Particle interference and apex crowding are shown to result in less efficient separations and represent undesirable regimes of dense medium cyclone operation. In order to avoid apex crowding, suitable medium to ore ratios and apex diameters should be used. Cyclone density differentials should be kept below approximately 400kg.m 3 to limit loss of efficiency due to excessive particle recirculation within the cyclone. The relationship between size-by-size partition curves shows that the flow split and density of the medium within a cyclone can be related to two new parameters, the pivot partition number and pivot density. The parameters are common to each partition curve in any set of size-by-size data and are mathematically related to the familiar performance characteristics, ecart probable (Ep) and separation density. The resulting expression confirms that the Ep and separation density are directly related.

Jan 1, 1986

By L Reynolds, N Whetter, S C. Cox

The Reefton Goldfield has had the largest hard-rock gold production (64 t Au) on the West Coast of the South Island of New Zealand, and is currently under renewed development by Oceana Gold. The gold predominantly occurs in variably sheared quartz veins that are associated with zones of tighter, shorter wavelength folds in the host Greenland Group metasediments. The quartz veins typically occur as a series of plunging shoots that align with specific fold limbs or fold hinge zones. Shear zones containing disseminated mineralisation and quartz veins have thickness variations that relate to the angular relationship between the shear and host-rock bedding. Exploration strategies and targeting can be developed around both types of structural control.

Jan 1, 2005

By Deutsch G. P

The output of an underground mine often depends entirely on the mine winding system. -Decisions made--at the design stage affect the economy and operation'of the mine'.througb -its entire life. A modern mine winding installation is an integrated system and its design requires a multidisciplinary approach including expertise in the-materials handling, mining, mechanical, civil, structural, electrical and control engineering fields. The paper-sets out the elements of typical mine wind- ing systems-and describes some of the more important decisions which must be made during the planning and design process, It is no longer.adequate to. base the choice of a system on the pre- ferences and experiences of individuals. Major Australian winding install- ations are usually designed on the basis of overseas experience and some of the detail design is often carried, out overseas. Differences in basic design criteria occur from country to

Jan 1, 1973

By C Fearon

This paper discusses the implementation of an underground rail haulage system during a major expansion of the Olympic Dam mine in 1998. The factors affecting the selection of rail haulage are discussed and details are provided on the rail system, which is designed to transport more than 10.5 million tonnes per annum (Mtpa). The reliability of the system during commissioning is discussed, including the decision to manufacture a ædummyÆ locomotive in order to keep the system operational. Finally, reliability improvements made both during and after commissioning are discussed with comments provided on the effectiveness of the system as it operates today.

Jan 1, 2005