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By Carlos G. C

Geological mapping in various parts of Australia is revealing a number of regional associations of mineralizations with particular persistent stratigraphic horizons. Such associations have been found in the Broken Hill district of New South Wales, in the Nairne district of South Australia, in the Mount Isa district of Queensland, and in the Cloncurry district of Queensland. The question has arisen as to whether such mineralizations are of sedimentary origin, syngenetic with the enclosing formation, or whether they are of epigenetic origin, and reflect the selective hydrothermal mineralization of favourable beds on a regional scale.The purpose of this investigation is to test the use of sulphur-selenium ratios as an objective method of distinguishing between suphide deposits or sedimentary or supergene origin, and sulphide deposits of hydrothermal origin, with particular application to the districts mentioned. At the same time much data has been accumulated as to the selenium content of Australian sulphide ores. The possible use of sulphur-selenium ratios for this purpose was first demonstrated by Goldschmidt and his coworkers (1933; 1935), and later by Carstens (1941). Goldschmidt and Strock (1935) found that pyrite of sedimentary origin had a sulphur : selenium ratio of the order of 200,000 or more, whereas pyrite of hydrothermal origin had a sulphur: selenium ratio of 10,000 to 20,000. Carstensfound that sedimentary pyrite deposits in Norway contained less than 1 g. Se per ton, whereas hydrothermal pyrite deposits contained 20 to 30 g. per ton.

Jan 1, 1954

IN this paper it is proposed to present certain features of operating practice at the Port Pirie works of The Broken Hill Associated Smelters Proprietary Limited, in the smelting in a blast furnace of lead ores carrying a high concentration of zinc.The subject matter selected for presentation is:(i) The effect of zinc on lead blast-furnace operations, together with an outline of the methods adopted in actual practice in dealing with the zinc problem.(2) Development of the height of tuyere above the bottom of the jacket, and the extension of the tapping interval and the combined effect of both factors upon the lead content of blast furnace slag.It will later be seen that one phase of the investigation carried out in connection with the effect of zinc on blast-furnace operations was largely responsible for the decision to increase to a marked degree the height of the tuyere above the bottom of the jacket.Due to this interdependence, it has been considered advisable to deal with the two features above mentioned.The high concentration of zinc in the lead-bearing materials smelted at Port Pirie has brought with it those troubles which are associated with zinc in the smelting operation.In the early stages of the history of The Broken Hill Associated Smelters Pty. Ltd. the trend towards increasing cost for labour, fuel, and stores, etc., rendered it necessary to increase the lead content of the charge, and reduce to a minimum the quantity of barren flux used.

Jan 1, 1931

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

Mesothermal gold deposits of southernAlaska 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 as 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 G Eastwood, C Joyce, P Ryan, G M. Johnston

Over the years, predictive techniques for Acid Mine Drainage (AMD) and the natural processes affecting acid generation have received considerable attention. Less emphasis has been placed on the sampling strategy and the integration of testwork results with the geological data base. The sampling strategy employed and the development of a geological model to determine the spatial distribution and volume of acid producing material are often crucial for developing cost-effective containment and mitigation measures. The geological model provides a link between the occurrence, timing, destination and placement of mined waste rock. Careful and accurate interrogation of a comprehensive geological database provides this linkage. The AMD testwork program at Cadia in NSW has been designed to identify the temporal selective handling requirements that will be required during operation. Sampling involved collection of representative combinations of all waste rock types identified within an extensive geological database. These samples were subjected to static, kinetic and accelerated weathering predictive tests. Preliminary results have been used to construct a waste block model for the deposit that identifies the quantity and distribution of acid producing material. Integration of the block model with the mine scheduling determines when the material will be mined.

Jan 1, 1996

By Waghorne E. P

The State Electricity Commission of Victoria is Australia's largest single coal producer. Approximately 19 Mt of coal will be produced in 1989 from the SEC V's newest mine, Loy Yang Open Cut (LYOC), which com- menced overburden stripping operation in October 1982. When the adja- cent Loy Yang Power Station is completed in the late 1990's, LYOC will supply between 35 to 45 Mt/a, depending on power station performance and demand of coal for non-power generation uses. LYOC has been a major challenge for the SECV. It is the biggest single open pit coal mining development undertaken in Australia, with a whole of life capital cost approaching A$1 billion. The mine has supplied a very rapidly growing demand for coal from the expanding power station while developing in breadth, length and depth. Coal demand has consistently been above the figures anticipated during the initial planning because of the substantially improved performance of the 500 MW units of the Loy Yang A Power Station. The superior performance of the LYOC and power station has generated additional electrical energy during the first 5 years of power station operation compared with the initial planning targets- at almost no additional capital cost. This has been a major benefit to the SECV. LYOC will continue to present major challenges for the SECV, particularly in achieving overburden removal and coal reserve targets as development of the open cut continues to full depth over the next 15 years.

Jan 1, 1989

By P Warner

Mines are often located in remote areas that are not well served by æstiffÆ power grids. Radial transmission networks, high lightning incidence (eg in South Africa the Witwatersrand experiences seven to ten strikes/km2 per year), low short circuit strengths and diesel generation are not uncommon. All these factors result in the electric power supply to many mines being unusually prone to dips and disturbances. æLegacyÆ winder drives û cyclo converters and dc drives û convert power directly from the supply to the motor, with no intermediate energy storage element. Further, they rely on the supply network for commutation and are therefore sensitive to supply voltage disturbances. There is a high probability that a dc or cyclo mine winder will trip during a supply disturbance, often resulting in lost production time and call-outs for technical staff to reset or even repair equipment. In contrast, a voltage source inverter (VSI) ac drive stores a large quantity of energy (in the dc link capacitors) and is fully self-commutating. Hence, this topology is inherently more immune to supply voltage disturbances. Indeed, vendors of ac VSI mine winders make general statements about the superior performance of their drives during supply disturbances. However, the advantages have apparently not been previously quantified. This paper compares different winder drive topologies and their sensitivity to supply disturbances, considers categories of supply disturbances and quantifies the cost of the effects on the different drive types.

Jan 1, 2005

By J Widjaja, E Hermawan, M Muharam, L Damanik

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The island of Java lies within the Sunda-Banda magmatic arc, which is characterised by multiple phases of volcanic activity and extensive compressional deformation. Along this zone, significant gold and copper mineralisation occurs, including some of the world’s largest deposits. In West Java, epithermal gold mineralisation is typically located in a series of extensional and strike-slip faults that cut Miocene to Pliocene volcanic rocks. These are all low-sulfidation, epithermal, vein-stockwork-style deposits developed in Miocene to Pliocene calc-alkaline volcanic rocks, which have been intruded by shallow-level plutons.This paper discusses an example of epithermal mineralisation at Mt Subang, West Java. Gold mineralisation was originally identified from stream sediment, panned concentrate and rock geochemistry sampling in the early 1990s. Geophysical surveys (magnetics and induced polarisation resistivity/chargeability), trenching, pitting and diamond hole drilling has subsequently revealed silicified-quartz vein epithermal gold mineralisation hosted within fault structures. It is clear that these structures acted as hydrothermal fluid pathways leading to the development of mineralised offshoots along north–south extensional and en-echelon arrays of north-east–south-west and transtensional faults. A number of vertical offshoots also occur in flexures and fault jogs. Post-mineral faulting has subsequently dissected and offset a number of the offshoots. Therefore, a detailed knowledge of structure and fault kinematics and displacement magnitudes is required in order to understand the geometry and continuity of mineralisation across major structures and maximise the resource potential. A range of exploration targets were modelled, indicating a minimum and maximum of 0.2 and 1.8 Moz of gold respectively.CITATION:Cunningham, M J M, Muharam, M, Damanik, L, Hermawan, E and Widjaja, J, 2015. Structural controls on the localisation of low-sulfidation epithermal mineralisation in West Java, Indonesia , in Proceedings PACRIM 2015 Congress, pp 227–234 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By G Simpson, S Dressler, A E. Levett

Tailings storage facilities often represent a mining operation’s most significant liability, posing serious environmental, social and safety risks. Almost all mining operations dispose of wet tailings (Valenta et al, 2023), which represents a risk of failure due to the potential for a rapid strength reduction of the unconsolidated materials leading to static liquefaction and subsequent dam wall failure. As a waste stream, tailings disposal, decommissioning and relinquishment aim to be inexpensive processes, ruling out many highly engineered solutions. Advantageously, tailings consolidation does not need to be immediate, opening the door for relatively passive, inexpensive consolidation methods that aim to gradually increase the strength of tailings over extended periods (ie years). In this paper, we present the prospect of novel in situ tailings stabilisation, learning from studies that have investigated the most erosion-resistant landforms on Earth.

Aug 2, 2023

Some of the major factors affecting ore reserve estimation in gold mines are discussed together with their impact on computational methods.The major priority in ore reserve estimation is to get sampling and geological problems resolved. Poor basic information cannot be remedied by mathematical methods.Generally the more complex a deposit becomes the greater the need for subjective assessment and the less applicable are more complex ore reserve methodologies.

Jan 1, 1984

By Townsend IJ

The Upper Triassic Leigh Creek Coal Measures which include a number of seams of sub-bituminous black coal are preserved in four small intramontane basins. The largest is Telford Basin, 1,000 m in thickness. The coals, of variable thickness and quality, are mined by open cast mining methods and utilised for generation of electricity at Port Augusta. The combined proven and indicated reserves are about 100 million tonnes.

Jan 1, 1975

This paper discusses recent ore reserve methodology at the Woodlawn base metal Mine in New South Wales. The ownership of the Mine changed hands in 1987 and a number of revisions to ore reserve practice were instigated by the new operators. While the overall modeling and calculation procedure remained essentially unaltered, the modifications and revised assumptions significantly increased the ore reserve. While general ore reserve procedures are discussed in this paper, it is the impact of these changed assumptions on the reserves which is our main focus.

Jan 1, 1990

By J S. Moema, R Paton, J Zimba

Today, most organisations are familiar with the pressure to increase their effectiveness and efficiency, regardless of the nature of their business. Cost cutting and increased productivity are the main themes of many initiatives to ensure the profitability of operations and, ultimately, shareholder satisfaction. It is well known that the cost of comminution to liberate minerals such as gold from their respective ores is a major expense for mines. Comminution costs consist predominantly of grinding balls and electricity. However, there are no national or international standard specifications for grinding balls û on which a single mine may spend several million dollars per month. In addition, in the past mines generally did not specify the minimum requirements when purchasing grinding balls from suppliers. The result is that every supplier has its own grinding ball recipe (regarding chemistry and heat treatment), and is under no pressure to implement a quality assurance plan to ensure that a consistent product is delivered. The resulting variation in the quality of grinding balls leads to increased steel consumption rates and hence increased milling costs. A more stringent quality plan will generally not be welcomed by suppliers since this may entail further investments and/or reduce the production rate. In a sense, suppliers benefit from poor quality grinding balls as this leads to increased sales. Perhaps the main problem is a lack of understanding of the factors that influence grinding ball performance. This paper will describe the factors that influence the wear rate of grinding balls from both a microstructural perspective and a mill perspective. In addition, some insights are provided on the different grinding balls available and ways that users can verify their quality.

Jan 1, 2007

By Else D

While the underground mining work environment may have processes and equipment considered unique, most of the broad issues likely to affect the occupational health and safety of employees are not. One such occupational health and safety issue that is common to the mining sector and most other industries is noise. Noise as an occupational health and safety issue is of national significance. Presently noise induced hearing loss costs Australia around $35 million per year on compensation claims experience alone. Noisy equipment and work environments are still being tolerated in parts of the mining industry as `part of the job'. Where work has been undertaken in noise management, considerable emphasis has been placed on either industrial hygiene monitoring programs or the provision of hearing protectors to miners working on or around noisy equipment.Opportunities for more cost-effective and long term methods for controlling noise exist. Ready to apply solutions to noise problems in the mining industry are available, but for many mining operators this information is often difficult to obtain. To overcome this problem, the SHARE program collects and distributes solutions to occupational health and safety problems. The program aims to help organisations to close the gap between what is known about solving health and safety problems and what is actually being applied at the shop floor level: Recent developments have incorporated the SHARE program concept into worksite hazard management projects that involve the participation of employee representatives, front line supervisors and engineering personnel. Besides providing workforce members with an increased understanding of hazard management skills, the SHARE in-house program results in the implementation and sharing of solutions to health and safety problems by the program participants.

Jan 1, 1992

The Coal Section of the Geological Survey of Queensland was formed in 1950 to plan and supervise systematic diamond drilling programmes to investigate the State's coal resources. For the first 15 years these programmes were con- fined to the established coalfields to prove reserves of coal suitable for steam raising for power generation. Adequate reserves were del- ineated during this period to provide coal for the operating lives of new power stations at Ipswich and Collinsville. Later exploration was aimed at a regional appraisal of coal mea- sure stratigraphy, particularly in the Bowen and Galilee Basins. This was followed, in some areas, by drilling to prove reserves to indic- ated status. Parameters were developed to allow a uniform approach to the estimation of reserves. Coal quality is evaluated in terms of potential utilization of coal. Reserves defined by exploration companies are assessed, and combined with reserves from Departmental drilling into a general table. Total reserves in situ amount to 9 962 million tonnes of coking coal and 7 333 million tonnes of non-coking coal. Approximately 20 per cent of coking and 40 per cent of non-coking coal were proved as a direct result of Geological Survey drilling programmes. Further explor- ation is planned for the Bowen and Galilee Bas- ins and may extend to the Surat Basin.

Jan 1, 1977

By Nevolina VG, Zakharova IB

The results of a study on the flotation of baddeleyite and associate minerals are presented, together with effective flotation reagents. Detailed microcrystallomorphological analysis of the benefication products were made to find out the features of distribution of different baddeleyite generations between froth and chamber products. To reveal the dynamics of interaction of technological properties of minerals with their morphology and constitution, a method of onthogenetic analysis was used. It is well known that the difference between technological properties of the particles of the same mineral depend greatly on its genesis, but also the relation is direct - by means of constitution (habit). Thus, flotation behaviour of minerals depends on morphology microinclusions, distribution of impurities, dislocations and physical properties of individual particles. The microrelief of baddeleyite grains and crystals from froth and chamber products was studied with an electron scanning microscope. Chemical composition was determined by means of laser, microprobe and chemical analyses. The difference between baddeleyite generations, their distribution in benefication products, and the effects of grain sizes, number of inclusions and chemical compositions were valuated. Conclusions on baddeleyite flotation properties were made. Mineralogical study on eudialite grains from rough ore and eudialite concentrate was carried out. The interrelation between eudialite and associate minerals and negative effect of aegirine on technological properties of eudialite were revealed as well.

Jan 1, 1993

Support design in jointed or blocky rock masses is often approached by the use of either 'rules of thumb', rock mass classification systems such as the Q-system (Barton, Lien and Lunde, 1974) or RMR (Bieniawski, 1973) or conventional wedge analysis. Generally, this requires that a number of key simplifying assumptions are made and the support system is designed to cater for either a mean, most likely, or worst case scenario depending on the risk tolerance. The design block size is often a major uncertainty and often a worst case block size based on excavation span is used. Thompson and Windsor (2007) state that it is inappropriate to base support designs on the excavation size as these size blocks rarely occur if discontinuity trace lengths are considered. Probabilistic keyblock methods can be used to determine the most likely design block sizes. A methodology is presented whereby JBlock software (Estherhuizen, 1996) is used to estimate potential block sizes as part of the support design process. Using information such as the spacing, orientation and length of discontinuities, it is possible to simulate blocks in the walls of an excavation (Esterhuizen and Streuders, 1998). Keyblock analysis methods (Goodman and Shi, 1985) are used to evaluate whether blocks are removable and whether the chosen support will be sufficient to ensure stability. Data from two mines is used to demonstrate how probabilistic keyblock analyses can be used in support design. Discontinuity data was used to generate 10 000 removable blocks and the design block size statistics were determined. For one mine this information was used to scale blocks in a conventional. Unwedge analysis whilst for the other mine, the point estimate method (Harr, 1987) was applied. The choice of appropriate design acceptance criteria in terms of factor of safety and probability of failure is also considered.

Nov 25, 2010

The economic viability of base metal and gold production projects at Chillagoe, North Queensland has been elusive or difficult to achieve. Because of isolation and low grades metallurgical efficiency has always been essential. This paper, concentrates on the Chillagoe Railway and Mines Company's operations from 1898 to 1914 and Elders Resources Limited's current developmental operations at Red Dome. The technological methods of concentrating, smelting and refining the copper, silver, lead and zinc by the Chillagoe Company will be outlined as well as their understanding of the geological aspects of the ore bodies and the stock market speculation. The Chillagoe Company failed in its economic management but developed the region. Elders Resources have successfully redeveloped the region including fostering the tourist potential of the area through their expert financial, engineering and metallurgical strategies within the external economic parameters of the Pacific Region.

Jan 1, 1987

By S E. Munro, P D. Munro

The commonly traded base metals concentrates of copper, lead, tin and zinc are sold by miners to custom smelters using contracts whose terms were generally established at the beginning of the 20th century or even earlier. Technical clauses in these concentrates for items such as payable metals and penalty elements do not reflect current realities of extractive metallurgical technologies and hygiene/environmental issues.It is an axiom that the miners and smelters have a symbiotic relationship. While the existing antique and arcane commercial arrangements serve the purpose of transferring money from the buyer to the seller, they are not likely to result in the industry achieving better overall technical and economic outcomes. By examining the cases for copper concentrates and zinc concentrates in particular, it will be shown that the practical application of these antiquated technical clauses does not drive the miners to produce the better quality concentrates that should be desired by the smelters. This is despite development of mineral beneficiation and hydrometallurgical technologies that would allow the miners to make better products.The adage that any extractive metallurgical problem in the smelter is cheaper to solve in the concentrator still generally holds.While nickel concentrates are only touched on lightly in this discussion because sales terms are more opaque than those for the other base metals, it is expected that the same conclusions will apply.CITATION:Munro, P D and Munro, S E, 2015. Base metals concentrate sales contracts – change Pavlov and the dog, in Proceedings MetPlant 2015, pp 46–60 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

By A Harris, N Fitzpatrick, F MacCorquodale

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Gosowong epithermal Au-Ag deposits, located on the island of Halmahera, North Maluku Province, Indonesia, are owned and operated by PT Nusa Halmahera Minerals, a joint venture between Newcrest Mining Limited (75 per cent) and PT Aneka Tambang Tbk (25 per cent).The Gosowong deposit was a greenfields discovery in 1994. Subsequent brownfields discoveries, most recently in 2009, have resulted in a total endowment of more than 6 Moz Au. The three main deposits include Gosowong, Toguraci and Kencana, and as of December 2013, production comprised 5.7 Mt Au at 24 g/t for 4.3 Moz with remaining resources of 4.2 Mt Au at 13 g/t for 1.7 Moz.Mineralisation primarily occurs in multistage veins, breccias and stockwork veins, with at least four texturally- and mineralogically-distinct vein events, including: banded crystalline quartz, quartz-adularia, quartz-chlorite and quartz-sulfide stages. Vein mode, texture and mineralogy are zoned around areas of maximum dilation, vein width and vein grade. Within banded quartz-chlorite, grades of >1000 g/t Au are common. Anomalous Au-Ag-Pb-As-Sb-K-Li geochemistry in rocks is commonly associated with the epithermal mineralisation. Four major types of hypogene alteration are recognised at Gosowong: silicification (quartz-illite-adularia-pyrite) within the immediate vein zone, argillic (illite-quartz-pyrite) alteration enveloping the vein zone, advanced argillic (dickite-kaolinite-quartz) alteration above and adjacent to the vein zone and within the overlying Kayasa Formation, and propylitic (chlorite-epidote-albite-calcite-pyrite) alteration within the footwall and distal to the vein zone.CITATION:Fitzpatrick, N, Harris, A, MacCorquodale, F and Wardiman, D, 2015. The Gosowong goldfield – a world-class epithermal gold-silver district in Indonesia , in Proceedings PACRIM 2015 Congress, pp 235–242 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

INTRODUCTION ò World coal production, Exporters and Importers òNew Zealand Exports, Markets and Products ò Types of Markets and Price Setting ò Bench Mark Prices and Exchange Rate ò Transport ò International Marketing - Key Factors ò Coal New Zealand , the Challenges

Jan 1, 1996