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By Terlich R. E, Finlayson J. M

A combination of high virgin rock temperatures, deep workings and extensive utilisation of heavy diesel equipment has presented North Mine (A Division of North Broken Hill Limited) with challenging ventilation problems. These problems have been addressed in a variety of ways which include in the order of 6000 kM of underground refrigeration. The future of North Mine depends on the successful development and extraction of ore in excess of 1100 m below the shaft collar using mechanised cut and fill mining. The success of this will depend on the installation of a complex chilled water reticulation circuit in this area. This will involve planning and constriction of a number of large dams, installation of pups and turbines, and the successful commissioning of several large water to air heat exchangers.

Jan 1, 1988

By Hayes P. C

The kinetics of reduction of PbO-silicate melts in CO-N gas mixtures at 900¦C have been studied. Rea~tion rates were measured by moni- toring the CO2 content of the product gas. A wide range of gas and melt compositions and gas flowrates have been investigated. The overall reaction rates in heterogen- eous systems are typically characterised by a steady increase as the gas flowrate is in- creased. At low flowrates the processes are limited by gas film mass transfer. At high flowrates it is expected that the rates will tend to maximum values determined by either the rate limiting chemical reaction or diffusion in the condensed phase. In the present series of experiments it has been found that for any given gas composition the overall reduction rate goes through a maximum with increasing gas flow. The maxima, which occur at relatively low gas flows, are more than an order of magni- tude greater than those observed at high gas flowrates. The results of these and other experiments are presented and analysed. Possible rate limiting mechanisms in the reaction system and their implications regarding commercial reactors are discussed.

Jan 1, 1987

The Direct and Indirect Effects of the Reagent Suite on Froth Stability in Laboratory Scale Batch Flotation Tests

Sep 13, 2010

A review of historic mining information and geological literature pertaining to the Alpine Mine, Lyell Goldfield has been completed. As a result of this work the Alpine reef is inferred to be associated with an upright anticline with a sub-horizontal axis. Structural profiles prepared from limited underground data indicate that the reef is subparallel to the eastern limb of the anticline and cuts across the western limb. Reassessment of structural mapping completed by the New Zealand Geological Survey indicates that Greenland Group metasediments within the Lyell Goldfield are folded into a series of opposed assymetic folds with sub-horizontal axes. It is suggested that the anticline which harbours the Alpine Reef is located on the axis of a synclinorium. Along the western limb of the synclinorium the subsidiary folds have steep west dipping limbs and shallow east dipping limbs (western sense of assymmetry) whereas shallow west dips and steep east dips are typical of the eastern limb. The notion of quartz mineralisation occupying the axis of a synclinorium is contrary to the situation in the Reefton Goldfield where quartz mineralisation is affiliated with folds associated with an anticlinorium. Historic mine data reveals that below No.4 Level the quartz-gold mineralisation, in the Alpine Mine, occupied a steeply dipping ore channel. The strike of the channel was to the northwest and within this structure the are shoots plunged to the north at approximately 40¦. Archival mine plans show that two quartz bodies, the North and South Blocks, were present at No. 4 Level. Although the North Block was followed down to No 14 Level (530 m vertically below the surface outcrop) the South Block was only mined as far as No 7 Level. Sampling on No 7 Level together with the results of trial mining suggest that the grade of quartz underfoot in South Block is low. Information from the Mines Statements and mapping undertaken by the Gold Prospecting Scheme reveals that faulting had a profound influence on the intregity and extent of the Alpine Reef. The reef occupies a Inajor shear zone but little is known about it. It is also apparent that below No 7 Level the reef was progressively shattered by faulting and this may be the chief reason for the decrease in grade in the lower levels of the mine. No substantive facts are available about wall rock alteration effects adjacent to the Alpine Reef Still this is not surprising considering that comments on the mineralised pug envelope and breccias adjacent to the mined quartz shoots at the Globe - Progress Prospect were omitted from contemporary publications. In spite of this the existance of sulphide bearing reef casing lithologies cannot be completely dismissed since 9.15 m of 'reef track' has been reported in Reids No 2 Level.

Jan 1, 1996

By Masters I. M, Ozberk E, Chalkley M. E

The integration of iron rejection as hematite with the Sherritt two-stage zinc pressure leach process has been investigated on the laboratory scale. The two-stage pressure leach process is applicable for a greenfield zinc plant, or for replacement of the conventional roast-leach circuit in an existing zinc plant. An excess of zinc concentrate is used to accomplish acid neutralisation in the first stage of pressure leaching, and the residual concentrate in the first stage residue is treated with an excess of acid solution in the second stage of pressure leaching to yield high zinc extraction. Integration of hematite precipitation with this process allows for the potential sale of the iron residue, greatly decreasing the residue disposal problem. Two flowsheets containing the desirable features of both of these processes are described in this paper, along with laboratory Results.

Jan 1, 1993

By Hirst H, McAfee J

In December, 1934, Mr. R. Sussex extruded some silver lead alloy wires in order to determine their electrical resistance. After the determinations had been made each wire was threaded through a sheet of paper on which the composition was noted. The wires were placed in a more or less tangled mass in a cupboard in March, 1935. It was not until September, 1936, that they were re-examined, and it was found that during the eighteen months some of the wires had corroded very badly. It was not until March, 1938, that the wires and the corrosion product could be examined, and the results are given in the following pages. It is of interest to note that none of the numerous silver-lead alloys which have been used for creep testing in the rolled condition have shown a similarphenomenon. The silver content of the rolled alloys was, however, never greater than 0·1%.GENERAL APPEARANCE OF THE CORRODED WIRESThe wires contained 0·1% up to 28% of silver, and a general examination showed that the corrosion had progressed farther the higher the silver content. This can be seen in Fig. 1, which is a photograph taken in March, 1938, of typical wires at a 'magnification of five diameters. In the early stages the corrosive action seems to be localized and an area of grey, yellow or reddish brown powder appears. The grey corrosion product is by far the one, most frequently seen, and in the later stages the only one visible from the outside. The reddish coloured product is sometimes seen on the residual metallic centre when the grey product has been broken away.The irregular extent of the corrosion can be seen in Fig. 2, which shows (natural size) the 5% silver wire after standing two years. The corroded parts are seen to be much thicker than the slightly corroded ones. The corrosion product, being non-metallic, is quite brittle and falls away from the wire on bending. In the extreme case the' whole wire has corroded and presents a cracked appearance as seen in Fig. 1 (281% silver).An approximate idea of the extent of corrosion can be obtained by measuring the diameter of the corroded part. The original diameter in each case was ·050/ ·051 inches and in Table I are given the diameters of the corroded parts after Hand 3 years respectively. When the diameter...

Jan 1, 1941

By M Stewart

The structural framework for the major gold deposits of the Reefton Goldfield was largely established in the 1930s after a detailed regional geological mapping programme. Recent new mapping has now substantially modified the structural framework of the Globe Hill - Devils Creek area and the Waiuta area. Using bedding-cleavage vergence as a method of establishing fold limb facing, many new fold structures have been identified, some of which conflict with long-established structures such as the Globe Hill and Waiuta anticlines. In addition, the mapping of areas of west- versus east-facing limbs constrains the position of many faults. The mineralised Globe-Progress Shear is one such fault which graphically demonstrates major structural discordance of the folds in the hangingwall compared to the footwall. Recognition of the folding is establishing the structural framework for understanding of the origin of these productive gold mining areas.

Jan 1, 1996

By M D. Goodz, Wright R. F

This paper highlights the importance of accurate observational technical reports compiled by Mining Geologists and Engineers. Before uncovering the original reports in July 1992, all previous investigations discounted returning to old mining areas on the belief that all operations were suspended because they were 'unpayable'. However, the detail of the original reports removed any doubt of the economic value of retrieving remnant ore.The important feature was that the description of 'unpayable' by GMA could be equated to 11.6 - 35 g/t over the history of the mine. On the basis of these reports the Morning Star mine has been re-opened.

Jan 1, 1993

By Ramsden AR, French DH

The limited contrast range of conventional black and white imaging does not enable full use to be made of the dynamic range of the video signal obtained from a scanning electron microscope or microprobe. The use of false colour substantially increases the information that can be derived from such images enabling relationships to be displayed that cannot be observed in black and white. This capability is now used extensively in combination with quantitative electron microprobe analysis as a research tool for ore characterization and host rocks studies related to minerals exploration in the CSIRO Division of Exploration Geoscience.

Jan 1, 1989

In October 2005 Phelps Dodge mining, a US based company, visited several Australian mining companies and mine sites to ascertain the current applications of risk management methods in the organisation. The results of this review, documented by the author, indicated a ælayeredÆ approach from high level site or major hazard analysis through to face level, æstop and lookÆ, methods. The approaches of several companies were summarised in one simple layered model. This model is helpful to other sites and companies to identify potential improvements but also offers an image of best practice that may assist with the governance of OH&S by both company boards and community regulators. The issue is particularly relevant as we discuss national consistency in mining regulation. This paper examines the layered model, the company and site approaches that helped define the model, as well as the suggested implications of the layered model to governance.

Jan 1, 2006

Research on the Thermodynamics of Siderite Roast Decomposition and the Experiment of Magnetic Roasting-Separation

Sep 13, 2010

Details are given of the excellent performance, outside Australia, of steel slag in road pavement surfacing. Laboratory tests and plant trials have shown Port Kembla BOF steel slag to be a material with properties suitable for producing asphaltic concrete which will maintain a high skid resistance in service under heavy traffic. The high density of steel slag is a factor which will result in a cartage cost penalty likely to restrict usage to close to its source.

Jan 1, 1979

The development of Western Mining Corporation's first commercial gold heap leaching operation is described. The laboratory testwork requirements for determining the amenability of ore to heap leaching techniques is discussed. Heap construction and operating practices are described; and production statistics and operating parameters are presented. It is shown that for a specific low grade gold ore a treatment cost optimization can be performed. Taking cognizance of the ore grade, percentage gold recovery, operating costs, and the gold sale price, it can be determined whether Carbon-In-Pulp (C-I-P) or Heap Leaching should be employed as the extraction process. The examples presented in this paper refer specifically to Kambalda and should not be used in themselves as generalities.

Jan 1, 1987

In a previous paper of this series (1) ,t it was shown that during the creep of single crystals of lead, deformation proceeded to some extent by means of slip on the octahedral plane. This was demonstrated by the formation of slip lines on the surface of the specimens. At first, a few broad bands appeared after a small amount of extension had taken place; then, as extension proceeded, more and finer lines made their appearance until the whole of the specimen surface was covered.The present paper deals with the process of deformation of the creep specimens as revealed by X-ray examination..By the use of this method, the changes taking place in the crystal structure can be observed.EXPERIMENTAL METHODThe method of preparation of the specimens, their size and the purity of the lead employed have been reported elsewhere (1). At frequent intervals, the specimens were dismantled from the test rack and X-ray back reflection photographs were taken. The specimens were so marked and set up on the X-ray machine that the same spot on the specimen surface was always examined.Copper radiation was employed, the tube voltage and current being 45 kV. and 25 m.a. respectively and the exposure time 2 hrs. The slit diameter was 1 mm.

Jan 1, 1941

An experimental study of the soil mechanics of brown coal showed that brown coal consolidates in the same manner as does a clay and that the theory of consolidation for soils may be applied to brown coals. Moisture content is a function of the coal type, the existing effective stress, and the stress history of the coal.The effective stress in a brown coal seam is a function of the overburden pressure, the pore stress and tectonic stresses. Stress history may be deduced from geological evidence and determined by consolidation tests. Application of these principles to the brown coal seams of the Latrobe Valley shows that the distributions of natural moisture contents are consistent with consolidation.INTRODUCTIONThe nature and geology of the brown coals of Victoria, particularly of the Latrobe Valley, were discussed in some detail by Edwards (1945, 1948), Thomas and Baragwanath (1949) and Gloe (1960). A salient feature of these studies was the distribution of moisture contents in the brown coal seams. Recent experimental work, part of a soil mechanics study of the structure and strength of brown coal, showed that moisture content variation is a reflection of consolidation phenomena in brown coal and application of the results to .field condItions verified and modified the conclusions of Edwards in his pioneer work. Further detail of this experimental work is recorded elsewhere (Rosengren, 1961).EFFECTIVE STRESS AND CONSOLIDATIONEffective stresses in soilsA saturated soil is a two-phase system, consisting of a compressible skeleton of rigid soil particles and pores filled with water, an incompressible fluid. (In this context, the terms compressible, incompressible, and rigid are relative only and refer to orders of magnitude). If this system is subjected to stress we define...

Jan 1, 1963

By B R, R Brooks, R Simcock, R Stewart

As environmental costs incurred by the mining industry become increasingly subject to critical analysis, new technology is necessary to ensure the further development of good relationships between the industry and community. Phytoremediation and phytomining are technologies that have the potential to capture the imagination and approval of the public. Phytoremediation , the in situ use of plants to extract heavy metals from a contaminated substrate, could offer an environmentally and cost-friendly alternative to traditional remediation techniques. Phytomining is the in situ removal of metals from a contaminated site or subeconomic orebody with the additional aim of recovering from the plant an economic amount of metal. Plants used in such operations, hyperaccumulators, accumulate large quantities of one or more target metals in their above-ground herbage. Upon harvesting and incineration, this plant material yields a low-volume, sulphide-free æbio-oreÆ, which can either be safely disposed of, or if the metal is of sufficient value, smelted. Investigations into the economics of phytomining nickel from ultramafic (serpentine) soils, showed that Alyssum bertolonii and Berkheya coddii could remove over 100 kg of nickel per hectare per annum from land with nickel concentrations well below the cut-off grade for conventional mining. It also appears possible to æinduceÆ the hyperaccumulation of gold into plants growing on gold tailings, or on stockpiled, low-grade gold ore. The plants used for phytoremediation and phytomining are useful colonisers as they are necessarily hardy and withstand extremes of salinity, metal toxicity and water stress that hinder the success of current revegetation procedures. As part of a rehabilitation operation, these plants may alter the geochemistry of a substrate making it more amenable to the growth of native species that should be used to restore a mining site to pre-operating conditions.

Jan 1, 1999

By M Allen

By its nature, the mining industry is energy and emissions intensive. In the future, the world will still require the outputs of mining but the industry will need to adapt to the low emissions economy. Understanding the risks of climate change to a particular site or at a company level is key to managing this transition.CITATION:Allen, M, 2018. Assessment of climate risk in the Australian mining industry, in Proceedings Life-of-Mine 2018, pp 13–16 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

In redesigning the cyanide plant at Mount Torrens, in conjunction with Mr. L. W. Grayson, the manager, several minor alterations were introduced in order to have the operations under thorough control, and these having proved serviceable may be of sufficient interest to merit a description here. The lixiviation vats, though only 8 feet in diameter, were retained, but the pipes leading away from the bottom were reduced from two inches to half-an-inch in diameter, and had a fall to the zinc boxes of about 4 feet. As these small pipes were completely filled by the solutions fiowing away from the vats, they exerted a suction equal to their fall and thus hastened the rate of flow, so that tailings containing a larger proportion of slimes could be treated than was possible where the larger pipes were used, as, there not being sufficient fiow of solution to keep the latter filled, no suction could be obtained with them. It was found that with'most of the tailings treated a sufficient flow could be obtained from the half-inch pipes when the taps on, them were only one-third to half open. The lower end of each of these pipes was connected by means on indiarubber tubing with the sille hole of 11 in aspirator bottle, and to the mouth of this bottle a few feet of similar tubing was connected, so that the solutions coming through could be directed into either of the fixed tubes leading respectively to the waste water tank the strong solution zinc boxes or the weak solution zinc boxes.In working the vats, the following method was found to give good results. While filling the vats with tailings the taps were left open, so that the water might drain off into the waste water tank the surface of the tailings was carefully levelled. When the strong solution was run in at the top, the air contained in the interstices of the tailings was forced through the half-inch pipe at the bottom as a strong blast, instead of, as I believe js usual, escaping by means of channels formed by it through the tailings, and thus tending, it would appeal, to render the disposition of the tailings less even and to make.

Australia has a long history of underground mining. Even withadvances in open cut mining equipment, techniques andeconomics, many orebodies are still best mined by undergroundmeans. In addition, modern exploration tools are æuncoveringÆorebodies that are at increasing depths. South African mines arecurrently producing from below 3 km, and developing down to5 km depths û it is likely that Australian mines will also becomemuch deeper over the next 20 years. One of the most significanttechnical challenges in deep mines is the problem of heat.Community expectations and legislated standards continue todrive operations towards improving the working conditions inmines. The hazards and costs associated with chronic hotworking conditions (heat illness, poor safety, poor productivity,higher operating costs and poor morale) are also becomingincreasingly recognised (Brake, Donoghue and Bates, 1998). Theexposure of miners to many other occupational hazards has beenreduced over the past 50 years. However, despite air-conditionedcabins greatly reducing the heat stress on mobile plant operators,there are still many Australian mine workers subject to levels ofthermal stress that existed a century ago. There are severalreasons for this, including a frequently-poor understanding of thephysiology of working in heat by mine management, no agreedmining code of practice for working in heat, the lack of a robust,practical-sized instrument to measure heat stress, the costpressures on the industry and, to some extent, deep-seatedtraditional management and worker practices. Howeversignificant progress has been made in many of these areas (Brakeand Bates, in press), with the net result that there is likely to be a trend towards installation of refrigeration of some form in manyAustralian mines in the future. This will add directly to the costof operation, but will also have direct and indirect benefits,including cost benefits. It should also be noted that Australia isnot at the forefront of adopting practices to manage temperaturesin the workplace: South African metal mines usually haverefrigerated cooling, and Canadian mines spend large sums onheating, with heating costs (averaged over a full year) of up to$A1 per tonne mined (Bandopadhyay et al, 1997). The history of mine refrigeration dates back to 1919 when thefirst plant was installed at Morro Velho, Brazil. By 1965, the totalinstalled capacity (worldwide) reached about 100 MW(R)i. Since 1965 the growth in mine refrigeration capacity has beenexponential, with a doubling every six or seven years (Howes andNixon, 1997). South Africa is by far the largest user of minerefrigeration, with over 300 refrigeration machines installed. This paper discusses the key design issues associated with theapplication of refrigeration in underground metal or coal mines.Whilst the emphasis is on large, surface plants, small, surface orunderground refrigeration plants can also be very effective in thecorrect application and many of the principles of design andoperation are the same.

Jan 1, 2001

Copper Recovery from Printed Circuit Board by Carbonisation

Sep 13, 2010