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Attempt has been made to determine the nature of charge on activated carbon surface by studying the electro-kinetic properties of the carbon in the presence of cations, anions and aurocyanide solutions. The zeta-potential measurements were made in the presence of individual ions and also in combinations. The cations and anions chosen were those commonly associated with gold bearing ores in Kalgoorlie area. It was found that the iso-electric point of Norit Carbon was at pH 4.45; below this pH the charge was positive, while above, it was negative. In the absence of gold cyanide solutions and in the presence of individual cations the i.e.p. shifted to the alkaline range (pH 7.2-8.5) while in the presence of anions the i.e.p. was shifted to less than pH 3.5. In the presence of aurocyanide solutions, the iso-electric point was still in the acid region irrespective of whether anions or cations were present. The probable mechanism for such a behaviour has been attempted after measuring the specific conductivities of solutions before and after gold adsorption, by studies using the electron- probe-mirco-analyser, and S.E.M. on the carbon surface.

Jan 1, 1982

There are still vast areas of Australia in which either the hydrocarbon potential has already been indicated but from which no hydrocarbons have been produced or else are completely untested. Despite the lack of recent new oil discoveries, it is anticipated that initial gas discoveries in these areas will be followed by oil discoveries as has happened historically. General exploration activities are continually providing new information that is being input to update previous hydrocarbon assessments for Australia, and all indications are that future exploration efforts will discover a lot of gas, some small oil pools and there is a chance to prove a major new oil province. Because of this, it is anticipated that reserves growth will continue at the average historical rate of about 200 MMB/year until the year 2000. The most frequent scenario will be costly exploration resulting in small oil discoveries and high development costs. This, in the past, has resulted in low profitability for Australian oil exploration, but windfalls for the Australian government.

Jan 1, 1981

By L Terrusi

The Bungaroo Valley hosts a concealed Tertiary channel iron deposit (CID) along a 17 km stretch of its length. Bungaroo Valley is approximately 0.5 km wide upstream at its easternmost extent, and 3.5 km wide downstream where it joins the Jimmawarrada Creek. The valley follows the axial trace of an anticline that plunges gently to the southeast, and the CID infills the valley. Mineralisation extends to a depth of 230 m below the surface, and almost the entire deposit occurs below the water table. Bungaroo Valley cuts through the Buckland Hills and is bounded to the north and south by steep scarps capped with the resistant Dales Gorge Member of the Brockman Iron Formation. Basement rocks are believed to be mostly Wittenoom Formation shales and dolomites, with Mount McRae Shale and Mount Sylvia Formation also present. Deep, localised depressions appear at the base of the CID sequence towards the north edge of the upstream section of the valley, while downstream the basal CID contact is relatively flat and shallow. In both cases the profile of the CID surface closely mirrors that of the basal contact. The localised depressions seen in the upstream basal CID contact produce significant variations in CID thickness of up to 100 m over short strike distances. This uneven palaeotopography is most likely due to eddying and waterfalls forming within the riverbed prior to CID deposition during a time when the water table was much lower than at present. It may also be associated with possible karsting in an underlying dolomite unit and subsequent syn- or post-depositional collapse of the overlying CID. The irregular basal contact of the Bungaroo CID sequence has implications for mining in terms of pit design and resource accessibility.

Jan 1, 2007

In recent years new instrumentation and digital technology have Wrote possible a new facet of goo-physics: broadband seismology. From digitally record-ing networks and arrays. broadband scistnograrns of body waves that are flat to displacement and veloc-ity in at least the frequency range from 0.01 to 5.0 liz can now be routinely obtained for most carthquakes of magnitude greater than about 5.5. In contrast to data from conventional narrowband seismographs, broad-band body waves have sufficient spectral information to nvest,igate the many frequency-dependent eflects that may arise from source finiteness and from wave prop-agat ion phenomenon. Besides the usual parameters of depth. moment and focal mechanism, broadband data have sufficient spectral information to provide estimates of radiated energy, associated stresses and the frequency dependence of source parameters. Moreover. teleseis-mically recorded broadband data and near-field strong motion accelerograms overlap in the frequency band be-tween about 0.1-2.0 Hz. Thus. v it h broadband data it is possible to connect far field and near field data in order to make estimates of acceleration for almost any seismically active region of the circum-Pacific.

Jan 1, 1990

By J McNee

Pike River Coal Limited (PRCL) is developing the Pike River Coal Mine in the Paparoa Ranges of New ZealandÆs South Island. The mine is being developed to extract a coking coal deposit of the Brunner Seam, some 46 km northeast of Greymouth, using a combination of continuous miners, road-headers and hydraulic extraction.   The mining area is located within Department of Conservation (DOC) land and is adjacent to the escarpment of the Paparoa Range and the Paparoa National Park. The mine will use its elevation advantage to hydraulically flume coal from the working faces to the pit bottom area where it will be slurried to approximately 35 per cent density of solids and pumped down a slurry line to the coal prep plant some 10.5 km down the Pike River Valley. The coal will be sold on the export market as a high quality coking coal for international steel making.   PRCL faces significant challenges to achieving the goal of cost effective production. The remoteness, high rainfall (greater then 6 metres per year on average), temperature variation and restrictions on access to this subalpine environment have driven the project to develop some distinctive solutions. These include the establishment of survey control in such a difficult environment with vertical and sub-vertical rock faces, significant vegetation and steep slopes by using helicopter survey, aerial photography and LIDAR (Light Detection And Ranging) aerial survey. PRCL has also commenced designing the placement of the main ventilation fans in an underground chamber in the stone drive.

Jan 1, 2007

By Jena, Anand S, Das R. P

Leaching studies were carried out on Indian Ocean manganese nodules using sulphuric acid as the lixiviant. By leaching the nodules with 8 per cent sulphuric acid for 12h at 100°C, copper and nickel could be completely extracted along with 50 per cent cobalt and 6.2 per cent manganese.94.2 per cent of the iron was also dissolved. To increase manganese and cobalt extraction, charcoal was used as a reductant. The role of charcoal was to reduce the manganese dioxide and render it soluble as manganese sulphate as well as to facilitate solution of the cobalt minerals associated with the manganese dioxide. Various leaching parameters were studied including acid concentration, amount of reductant, leach time, pulp density and leach temperature. It was found that by leaching the nodules with 10 per cent sulphuric acid at 100°C for 4h using 5 wt/wt per cent charcoal (0.05g of charcoal per g of nodule) almost complete extraction of copper, nickel, cobalt and manganese could be achieved. However, under these conditions all the iron present in the nodules was also leached.

Jan 1, 1989

By Martin C. H, Met B

INDEX OF CONTENTS:1. Introduction, Explanatory; and Reasons for Coal Cleaning.2. Principles on which Coal Cleaning is based.3. Location of Broken Hill Proprietary Co. Ltd. Plant.4. Description of Processes Selected Barvoys Bath Process; Barvoys Medium Preparation and Treatment; Static Dry Cleaning Plant.5. Detailed Description of Plant.6. Typical Results of Cleaning Operations.INTRODUCTION, EXPLANATORY, AND REASONS FOR COALCLEANING:The Institute proceedings have not previously published any matter on coal cleaning and the reasons thereof; in consequence it has been deemed advisable to allot a part of this paper to explanatory matter, prior to entering into a detailed explanation and description of the Newcastle plant.At the outset it would be as well to consider briefly the kinds of materials from which coal has originated. All coals represent some stage in the decomposition and transformation of vegetable matter laid down in prehistoric times, the vegetable matter undergoing numerous geological changes, such as submergence, overlaying by sediment, with subsequent pressure and re-elevation; these processes may...

Jan 1, 1946

By Bradford NL

The Isa Mine of Mount Isa Mines Limited produces 5.1 million tonnes of copper ore and 2.2 million tonnes of silver-lead-zinc ore from sublevel open stopes annually. Extraction of the narrow, steeply dipping silver-lead-zinc orebodies requires a strategy quite different to that used in the massive copper orebodies. A range of blasthole diameters, explosive types and initiation systems gives the flexibility needed to adapt open stoping to a variety of situations. Hole diameters from 70 mm to 200 mm are being used, with lengths of up to 100 m common for the latter.

Jan 1, 1982

By H Ramandi, H Masoumi, I Canbulat, B Hebblewhite, J Oh, S Saydam, W Timms, S Mo

This paper reviews the floor heave mechanisms in underground coal mine roadways. Previous studies have reported three main failure mechanisms: bearing capacity failure, buckling and swelling. The buckling failure has been observed where immediate floor strata are relatively strong and thinly bedded. On the contrary, the weak floor strata have been associated with both the bearing capacity failure and swelling mechanisms. The bearing capacity floor failures are likely to induce other types of instability such as pillar punching, tensile failure of pillar, roof fall and subsidence as well as floor heave. Despite a considerable amount of research, predicting the magnitude, location and timing of floor deformation is challenging with current state of knowledge. CITATION:Mo, S, Ramandi, H, Oh, J, Masoumi, H, Timms, W, Canbulat, I, Hebblewhite, B and Saydam, S, 2018. A review of floor heave mechanisms in underground coal mine roadways, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 196–206 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

General Gold was discovered in quartz veins at Wiluna in 1896, and the first lode was discovered in 1904. Since 1896, some 2.5 million ounces of gold have been produced from the Wiluna area. The mining operations at Wiluna are 100 per cent owned by Wiluna Gold Pty Ltd, a wholly owned subsidiary of Wiluna Mines Ltd. Oxide and sulphide gold ore is extracted by conventional open pit mining techniques, and ran-of-mine ore is processed through two separate circuits. The oxide circuit has a capacity to treat 600 0(X) tonnes per annum and the sulphide circuit has a capacity to treat 400 (XX) tonnes per annum. Additional gold is won by dump leaching sub-grade oxidised ore and by retreating of primary ore flotation tailings from previous operations. Testwork carried out in 1990 indicated the viability of leaching dumps of run-of-mine oxide ore, and in June 1991 Signet Engineering of Perth, WA, was awarded an EPCM contract to construct a nominal 2.5 million tonne dump leach facility, for a total construction estimate of 51.75 million.

Jan 1, 1994

By Jensen B, Ofori P, He Y, White E, Stanmore B, Brien M, O&apos

As part of a large AMIRA project, an on-line moisture meter was installed at two mine sites in Central Queensland. This project investigated the factors which control the moisture content of coarse (>0.5 mm) coal from the centrifuges used in conventional coal preparation plants. It was placed immediately after the first centrifuge to isolate the factors pertaining to one machine and its feed.The meter was found to be accurate and precise when compared with manual and mechanical sampling methods. The Grubbs estimator technique indicated that its precision is better than 0.3 per cent at the 95 per cent confidence limit.It has been identified that:1. the variability of the measured moisture contents of coarse coal can be described by normal distributions. Standard deviations of about 0.6 per cent are common; and2. the treatment of the coarse coal on the drain and rinse screens immediately prior to the centrifuge can affect the final moisture content.

Jan 1, 1995

Flat jack stress determinations in selected colliery roadways have revealed a range of measured stress from 330-p.s.i. tension to 3,750 p.s.i. compression. Photoelastic examination of loaded plastic and actual rock mo.odel mine openings has shown that the primary horizontal stress required to attain these measured stresses would be from one to three times the superincumbent vertical load.Examination of roof movement with a. borehole oxtensumeter and a series of anchors at various horizons to 30 feet in a. vertical roof borehole showed that when a standing face waa.s advanced the roofmovement was practically confined to the lower two feet. The ma.j ority of this movement occurred during the 36 hours after mining at this face commenced.The use of a. radioactive isotope and a. scintillation counter in a. pair of parallel bcreholes promises to be sensitive and accurate method of roof bedding plane crack detection.

Jan 1, 1963

Methane is present in varying degrees in nearly all underground coal mining operations. At mixtures with air near 5-15% it is explosive and consequently since it is not usual for these levels of contamination to be reached in the general body of a mine ventilation system it is not unusual to experience it in specific places. On longwall faces the most used power loader is the shearer machine and because of its general shape, situation and operation it is likely that all the factors which are required to cause a frictional ignition can be present. This paper makes a general appreciation of the causes of these ignitions and methods which are and have been used to control these situations on and around these machines.

Jan 1, 1981

By King D, Dickinson S. B, Matheson R. S

Commencing in 1956, Rio TInto Australian Exploration Pty Limited in association with Electrolytic Zinc Co of Australasia, Limited, has been carrying out a mineral prospecting program in North-West Tasmania over an area of about 4000 square miles.The program has comprised extensive airborne geophysical surveys, detailed geological mapping, ground geophysical and geochemical investigations. Out of the wealth of new data, and the examination of previous records, has emerged a new structural concept of regional ore control and distribution in North-West Tasmania. This roncept stems from the discovery of an ancient 'fossil' rift valley (graben), named the Owen Rift Valley, along which are located the major mines of the area and numerous well-known prospects. The known mines and prospects from north to south include Mt Bischoff (tin); the Pinnacles (zinc, lead, ropper); the Chester (pyrites); Rosebery-Hercules (lead, zinc, ropper, silver, gold); Mt Tyndall (lead, ropper, zinc); Comstock and Tasman (copper, lead, zinc); Mt Lyell (copper, pyrites, gold); Mt Jukes and Mt Darwin (ropper). The identification of the West Coast (Owen Conglomerate) Range as a fossil rift valley is due to Or B Campana, who carried out extensive geological mapping and interpretation work, and who, with S B Dickinson, are the senior authors of this paper.S B Dickinson, who introduced B Campana to the geological problems of West Tasmania, had previously investigated the Mt Lyell and Rosebery mining fIeld, to which reference is made in this work.D King assisted in the regional mapping and in providing numerous data on the mineral distribution of the area.R S Matheson rontributed to the fmdings on ore emplacement and rontrol in the discussions held on this subject. They are accordingly included as joint authors of this paper.Credit is also due to E McCarthy, who interpreted the geophysical results, and to J H Rattigan, who compiled the preliminary geological maps from published documents and by photo-geological methods.G Hall and V H Cottle, of the Electrolytic Zinc Co in Rosebery, provided invaluable geological data and suggestions in the course of the survey, and made a constructive criticism of the manuscript of this work. The airborne geophysical survey carried out by the Adastra-Hunting Geophysics Ltd company, furnished useful data which substantiated many of the fIndings on the stratigraphic and structural relationship. The Mines Department of Tasmania and S W Carey, Professor of Geology at the University of Tasmania, were instrumental in initiating the regional survey and provided the published and unpublished geological literature on the area.The authors also wish to acknowledge the invaluable assistance received from the Mt Lyell Mining and Railway Co in Queenstown, which made available the more recent geological and mining documents rompiled by M L Wade and M Solomon.

Jan 1, 1994

By Real F, Carvalho P

During the development of the Neves-Corvo Underground Copper Mine, since 1981, inflow of water has been encountered in the mine workings, which consist of a ramp from surface 5 km long, a shaft 575 m deep and access crosscuts through the massive sulphide orebodies of Neves, Corvo and Graga, which are three of the four known deposits up today. Mine-hydrological studies have established the main characteristics of the hydrological system and its evolution in space and time. In a geological setting of low permeability rocks of Paleozoic age, tectonically affected by thrusts and faults, this has involved consideration of the relation with surface and ground water as a result of mine dewatering processes. The hydrological systems are described and summarized in this paper together with the techniques employed to study their origin and evolution, namely hydrochemistry, thermometry, piezometry and isotopic tracers.

Jan 1, 1988

By Morley C

The Mount Charlotte gold mine is located 0.75 km east of the General Post Office in Hannan Street, Kalgoorlie WA and about 3.5 km north of the Fimiston Operations on the famous Golden Mile.Mechanised underground bulk-mining at Mount Charlotte has been in continuous operation since 1963. For the 30-year period ending December 1992, the mine produced 22 million tonnes (Mt) of ore for a recovery of 2.73 million ounces. During 1991/92, the mine produced 1.53 Mt of ore at a head grade of 3.15 gramshonne (g/t) for a recovery of 135 822 ounces.The principal ore source at Mount Charlotte has been the Charlotte Orebody which is now largely mined out. Since 1990, approximately 75 per cent of production has been sourced from the Reward Orebodies. The Charlotte Orebody was a relatively homogeneous quartz stockwork with simple geometry and average bulked grades in the range of 4.0 to 5.5 g/t. This is in contrast to the Reward Orebodies and the more recently defined Charlotte Deeps and Maritana Stockworks, which have complex grade distribution and geometry with lower average bulked grades (2 to 4 g/t). The lower grades are principally due to the decreased density and volume of stockwork venation and related vein halo alteration. Typically, these stockworks comprise a patchy mosaic of quartz veins and vein swarms, with irregular distribution and geometry within the quartz gabbro host rock.

Jan 1, 1993

The design of mine ventilation systems for the BHP Steel Division Collieries is based on the acquisition of ventilation survey data for the establishment of a realistic computer net- work model. The branches which form the net- work for the computer models are calculated from a range of resistance factors incorporat- ing both a frictional and shock loss component. Since shock losses can account for up to 30 per cent of the total energy losses in mine airways the use of friction factors alone without accounting for shock losses will result in the choosing of an insufficiently performing fan. Published tables of friction factors have in- variably been taken from metalliferous or single entry studies and consequently are not reliable for Australia's mining conditions where multiple entries with regularly spaced cut-throughs are the normal practice. Typical resistance factors for roadways of rectangular cross-section 5.5 m x 2.0 m, with coal sides, have been found to vary from 0.11 Ns2/m8/km where no timber supports are used, to 0.98 Ns2/m8/km where double centre legging together with wooden chocks is used. In addition to the range of resistance factors due to varying support methods, the nature of use for a roadway is very significant because of the condition of repair and upkeep maintained.

Jan 1, 1983

By Brimblecombe P

Morwell Open Cut is a continuous mining operation employing 5 buck- etwheel excavators, I bucket chain excavator and 54 conveyors. The combined bunkering capacity at both client Power Stations represents less than 12 hours maximum coal demand. This creates an extremely dynamic operating environment, which is further complicated with significant variations in both excavating and transportation plant capabilities. To achieve set objectives, including- I adequate reserves, 2 coal supply reliability, 3 cyclic plant maintenance, 4 minimal cost of coal, scheduling of the operation requires constant monitoring and reappraisal. Investigations are in progress to develop a computer based scheduling tool capable of simulating the complex operating environment. A review of computer scheduling packages currently available within the State Electricity Commission of Victoria has found limitations making most unsuitable for the task. The type of package found to be most suited is a knowledge based system ('Expert System')capable of operating within a set of rules defined by the user. Work is proceeding on the development of a knowledge base to test the effectiveness of Personal Computer based `Expert Systems'.

Jan 1, 1989

By A J. Clough

There has been an unprecedented rise in the fatality rate in the Australian mining industry over the last few years. The factors behind this rise are not clear; however, it is noted that the increase in fatalities has occurred during a fall in commodity prices.This paper examines prevention methods and systems to deal with hazards that have the potential to result in either single or multiple fatalities. Managing the risks associated with mine ventilation is used to illustrate the principals behind the approach.The paper also touches on the broad science of human error and proposes a multifaceted approach to controlling and preventing fatal risks.A summary of the steps involved in developing an effective principal hazard management plan is provided.CITATION:Clough, A J, 2015. Ensuring an effective principal hazard management plan, in Proceedings The Australian Mine Ventilation Conference, pp 3–8 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By Warren L. J

The recovery of phosphate minerals from the Mt Weld deposit by froth flotation has been studied by many researchers. Most of the flotation experiments were carried out with a tall oil fatty acid as collector and sodium silicate as dispersant and gangue depressant at pH about 10. Several rougher stages and cleaner stages and, sometimes, a desliming stage were included. The major difficulty was to reduce the Fe2O3 impurities in the concentrate to the required level. We used QEM*SEM (Quantitative Evaluation of Materials by Scanning Electron Microscopy) to provide a comprehensive and accurate mineralogical analysis of the flotation products. The analysis indicated that the Fe2O3 impurities were mainly recovered in the second concentrate, owing partly to the incomplete depression of the liberated iron oxides by the sodium silicate and partly to composite particles containing iron oxides. The selective depressing action of sodium silicate was improved by adjusting the variables such as the modulus (SiO2/Na2O), pH and time of standing of the stock sodium silicate solutions or by adding some polyvalent metal salts into sodium silicate solution. The flotation process was optimised to produce a phosphate concentrate with the required grade and recovery (38.6 per cent P2O5, 2.67 per cent Fe2O3, 13.7 for P2O5/(Fe2O3 + A1203), at P2O5 recovery of 81.5 per cent). The possibility of recovering the rare-earth phosphate, monazite, from the Mt Weld deposit by flotation was also studied.

Jan 1, 1991