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By H W. Wu, D Humphreys

The structure of a comprehensive research project into mine fires study applying the Ventgraph mine fire simulation software, preplanning of escape scenarios and general interaction with rescue responses is outlined. The project has Australian Coal Association Research Program (ACARP) funding and also relies on substantial mining company site support. This practical input from mine operators is essential and allows the approach to be introduced in the most creditable way. The effort is built around the introduction of fire simulation computer software to the Australian mining industry and the consequent modelling of fire scenarios in selected different mine layouts. Application of the simulation software package to the changing mine layouts requires experience to achieve realistic outcomes. Most Australian mines of size currently use a ventilation network simulation program. Under the project a small subroutine has been written to transfer the input data from the existing mine ventilation network simulation program to æVentgraphÆ. This has been tested successfully. To understand fire simulation behaviour on the mine ventilation system, it is necessary to understood the possible effects of mine fires on various mine ventilation systems correctly first. Case studies demonstrating the possible effects of fires on some typical Australian coal mine ventilation circuits have been examined. The situation in which there is some gas make at the face and effects with fire have also been developed to emphasise how unstable and dangerous situations may arise. The primary objective of the part of the study described in this paper is to use mine fire simulation software to gain better understanding of how spontaneous combustion initiated fires can interact with the complex ventilation behaviour underground during a substantial fire. It focuses on the simulation of spontaneous combustion sourced heatings that develop into open fires. Further, it examines ventilation behaviour effects of spontaneous combustion initiated pillar fires and examines the difficulties these can be present if a ventilation reversal occurs. It also briefly examines simulation of use of the inertisation to assist in mine recovery. Mine fires are recognised across the world as a major hazard issue. New approaches allowing improvement in understanding their consequences have been developed as an aid in handling this complex area.

Jan 1, 2005

Flotation testing has been done at laboratory scale on hematite mineral and ore samples using stage additions of various hydroxamates. Chemisorption of hydroxamate species onto the hematite surface was inferred from the results, possibly involving both the undissociated hydroxamic acid and hydroxamate ion as maximum recovery occurred close to the pKa of the hydroxamic acid. Flotation testing on a specular hematite ore containing 40 per cent Fe and 42.5 per cent silica gave highest iron grades in concentrate at pH 6, in contrast to published data which suggested pH 9 as the optimum value for ore processing. Using octyl hydroxamate, a rougher concentrate assaying 67 per cent Fe at 51 per cent recovery was obtained using four stage additions of 50 g/t at pH 6. For lower grade concentrates still meeting the chemical analysis for pigment grade micaceous hematite (minimum Fe assay 60 per cent) iron recoveries of 80 per cent were possible for stage additions of 50 g/t octyl hydroxamate in the pH range 6-8.

Jan 1, 1999

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

The Small Pebble Process for Reducing Ball and Power Consumption in Secondary Grinding Ball mills are used widely for secondary grinding. A mixture of ball sizes can be used to optimise grinding efficiency, but the use of balls smaller than about 30 mm in diameter is not normally viable, particularly when alloy steel is required. Preliminary testing of the grinding efficiency of various combinations of 40 mm steel balls and crushed stone in the size range 7 to 25 mm was carried out in a 300 mm diameter mill, which has accurate power measurement.The primary interest was to assess the potential benefit of adding small pebbles (from a primary circuit crusher or mill) to a secondary ball mill, to reduce ball consumption and to improve grinding efficiency. The optimum proportion of pebbles was found to be about 25 per cent by volume. This mixture produced about the same amount of fines as balls alone, but with lower power consumption, due to the lower density of the pebbles. The net result was a 12 per cent saving in power and a 25 per cent saving in ball consumption. The production of fines was partly due to pebble wear. The use of portions of 15 mm balls, (ceramic and steel), was also tested for comparison. A few batch pilot-scale tests were conducted in a 1.2 m diameter, 0.31 m long mill to test the viability of the pebbles at a larger scale. The pilot-scale tests confirmed the reduction in power and that the rate of production of fines was the same as that obtained with balls. The same residence time was used and this implies that pebbles can be added to an existing full-scale ball mill, with no loss in capacity. Samples of secondary mill feed and pebbles were obtained from a copper mine and the steady-state consumption of pebbles was determined by locked-cycle laboratory-scale tests. These tests demonstrated that mill power could be reduced by up 13 per cent and that the consumption of 40 mm balls could be reduced by up to 38 per cent, while maintaining the same throughput and product size. The rate of pebble addition was about 4 per cent of the primary circuit feed rate. Application has been made for patent protection.

Sep 13, 2010

CONTENTS.IntroductionAcknowledgementsDescription of MineVentilation of MineOrganisation of Fire Fighting SquadsTraining of Fire Fighting SquadsRescue WorkFire Fighting and Rescue EquipmentFire AlarmsConclusionINTRODUCTION.This paper should be read in conjunction with that by R. P. Hooper, entitled "Underground Mine Fire Prevention at the South Mine," Broken Hill. Contents of the paper have been arranged similarly for easy reference. The methods used in educating employees in the use of Proto apparatus remain basically the same, but many changes in the methods and equipment used in subjugating fires have been brought about by the practical experiences gained by officers of the company in extinguishing the outbreaks which occurred in the latter half of 1944.Three fires took place during this period, the first in July, on M.L. 11 in openings leading to timbered workings previously worked and subsequently abandoned by...

Jan 1, 1946

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

Sep 13, 2010

Any hypothesis for the origin of the Otago gold-quartz lodes must account for the following observations. 1. Southeast of Glenorchy, where the schists hosting the lodes are comparatively unaffected by Neogene Alpine Fault deformation, the dominant strike of the vein systems is NW-SE, parallel to the axis of greatest post-metamorphic uplift in the Otago Schist belt (Paterson, 1986). 2. The lodes are fault-hosted, with some developed along steep, low-displacement normal faults (eg Barewood, Bendigo, Nenthorn), implying NE-SW extension, and some developed along low-angle thrusts (eg Macraes) implying, in apparent contradiction, NE-SW contraction (Teagle et al, 1990). 3. The mineralising fluid was of metamorphic origin (McKeag and Craw, 1989), but while some of the lodes developed in a mesothermal environment at considerable depth (eg ~10 km for Macraes), others appear to have formed at very shallow depth (eg <1 km for Nenthorn) (Craw and Norris, 1988). 4. The timing of the mineralisation is generally poorly constrained but postdates the main Rangitata schist metamorphism. It probably initiated during early Cretaceous exhumation and unroofing of the schist belt (140 - 120 Ma?) and may have continued well into the Tertiary (Craw, 1989). Estimates for the relative ages of the different lodes are largely speculative but, based on pressure estimates from fluid inclusion studies, Macraes likely represents the deepest and oldest lode system while Nenthorn (just 12 km to the southwest) is perhaps the shallowest and youngest (Craw and Norris, 1988).

Jan 1, 1992

The Tasman Orogenic Zone is regarded as a single metallogenic province (the Tasman Province) with four SUb-provinces corresponding with its major tectonic components: the Lachlan, New England, Hodgkinson.and North Queensland orogenic provinces. Within the Tasman Province there are four main ore-rock associations.These are1. manganese and iron with sedimentary and basic volcanic rocks,2. zinc-lead-copper and copper with intermediate-acid volcanic sequences,3. minor chromium, platinum, and osmiridium with ultramafic complexes, and4. tin, wolfram, gold, and copper with syn- and posttectonic granitic intrusions.Whereas the ores of ultramafic and volcanic associations form geographically-restricted metallogenic districts, the ubiquitous granitic ores may be subdivided into twenty-one districts that cover almost the entireOrogenic Zone. The Tasman Province is notably lacking in uranium ores and Mississippi Valley-type deposits.There is a distinct tendency for ores of each association to be progressively younger to the east and north, thus paralleling the progressive growth and stabilization of the Zone. Similar ore-rock associations are present in repeated phases of mineralization from the Cambrian to the Permian-Triassic, reflecting the essential homogeneity of the Tasman Province, and the similarity of the successive tectonic cycles.

Jan 1, 1972

By S F. Simmons, J Fleming

Alteration and mineralisation at the Island Copper deposit is related to the intrusion of Early Jurassic quartz feldspar porphyry dykes into surrounding comagmatic Bonanza volcanic rocks. The pyrophyilite alteration zone forms an upward flaring cone, largely hosted within a breccia body that cross-cuts the Co, Mo, and Au-rich ore shell. This alteration zone contains pyrophyllite, dumortierite and diaspore and resembles alteration occurring in some high-sulfidation deposits, but which is barren. Fluid-mineral equilibria and fluid inclusion studies indicate formation at approximately 300 ¦C from fluids dominated by steam and gases. These fluids appear highly acidic, but sulfur poor, leading to extreme base leaching within the breccia body and surrounding rocks.

Jan 1, 1995

By Y Lanwin

The Australian mining sector is undergoing a significant transformation with the adoption of advanced technology to the operational landscape. This has highlighted a critical disconnect between our traditional educational systems and the skill requirements of working with these advanced technologies. This paper aims to provide a behavioural science analysis of how the traditional manufacturing mindset, deeply rooted in our educational frameworks from primary to tertiary education, registered training organisations (RTOs), and in-house learning and development, is misaligned with the needs of today’s technologically advanced mining operations. Originating in the industrial revolution, the manufacturing mindset prioritised efficiency, mass production, and the division of labour. In educational institutions, this translated into an emphasis on rote learning, linear examinations, and a rigid adherence to processes and procedures. Such a system, while effective in producing a workforce suited for repetitive and predictable tasks, falls short in fostering skills like problem-solving, adaptability, flexibility, and coping with change – skills that are increasingly vital in a mining sector dominated by automation, robotics, and AI. The paper discusses how the focus on disciplined adherence to standard work procedures and processes in educational and training programs has inadvertently stifled creativity and autonomy in learners. This issue is compounded in the workplace, where employees, having been conditioned to operate within strict guidelines, now face the challenge of adapting to environments where autonomous decision-making and creative problem solving are crucial. In essence, the traditional approach to education and training has prepared individuals for a world of work that no longer exists. This paper advocates for a whole of pipeline approach, grounded in behavioural science, to revamp mining education and training. It highlights the importance of understanding and influencing the behavioural aspects of learning and recommends for an approach that promotes diversity, critical thinking, and adaptability, preparing the workforce to excel in the rapidly changing landscape of the Australian mining sector.

Sep 1, 2024

The interaction of flotation collectors with sulfide minerals takes place at the solid - solution interface. The electrochemistry of the processes which affect this interface are discussed. The interaction of xanthates with sulfides is an electrochemical process, xanthates being electro-oxidised to chemisorbed xanthate and dixanthogen. The role of oxygen is to provide a cathodic process to allow the anodic oxidation to occur. The hydrophobic condition of the mineral surface is brought about by the presence of the oxidised xanthate species. The action of reagents which can activate or depress the flotation of sulfides is discussed briefly.

Jan 1, 1971

The Hishikari gold deposit, discovered by the Metal Mining Agency of Japan, has become a giant class epithermal gold deposit with the highest grade of gold yet recorded in the world through detailed exploration and development by the Sumitomo Metal Mining Co Ltd. The exploration strategy involved a regional approach combining geological and gravity surveys over a 900 km2 area which had historically produced over 120 t of gold. These surveys were carried out to grasp the common geologic features of epithermal gold deposits in the survey area. A genetic model for epithermal gold deposits in the area under regional survey was also considered based on detailed research of the Kushikino epithermal gold deposit which was in operation at that time. This model was applied to the targeted areas, and important relationships between mineralisation, host lithology, intensive propylitic alteration and gravity highs became apparent. The Hishikari block was selected in this way and bonanza gold was discovered during drilling. Since the development of the Hishikari mine, information useful for further exploration for the same type of deposit has been accumulated.

Jan 1, 1995

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

Upon cessation of mining activity open-cast mine pits typically fill with water, forming a æpit-lakeÆ. The water in these lakes, in some instances, contains high concentrations of ædeleteriousÆ material. Containment and/or dilution typically requires an understanding of how stratification in the pit-lake will develop over a long timescale (say 100 years). Vastly different transport rates can develop due to differing hydrogeochemistry, basin morphology and climate. Numerical (computer) modelling is the most likely approach for successful prediction over long times. While lake modelling tools are available, useful numerical modelling requires improved understanding of transport in such systems because they are different to natural lakes in a number of ways. Notwithstanding the effort required to improve our understanding, the modelling provide a means of testing approaches to active management of pit-lakes.

Jan 1, 2002

The Upper Waimangaroa mining permit is part of the Buller Coalfield and lies on the eastern side of the Stockton-Denniston Plateau. The mining permit area is estimated to contain a total in-ground coal resource of 58 million tonnes, contained within 13 separate coal resource .blocks. The coal is Bituminous High Volatile B rank with export potential as semi soft coking or thermal coal. The Northern Opencast mine is the first mine proposed for Upper Waimangaroa and consists of the three resource blocks at the northern end of the permit area. The highwall of the mine will cut into the Mt William Range resulting in overburden cover of up to 150 metres in some areas. The ability to rehabilitate the area after mining was a major consideration in the design of the mine. The Northern Opencast area has been geologically mapped, extensively drilled and effectively modelled using Vulcan software. Three distinct coal seams are present and the mineable in situ resource is estimated at 8.7 million tonnes of which approximately 7.1 million tonnes is likely to be recoverable. It is proposed that this resource will be mined using opencast methods and the void will be backfilled with overburden. The life of the mine is at this stage estimated at 19 years based on an annual production of 500,000 tonnes at 1.8% sulphur and the Upper Waimangaroacoal will be blended with low sulphur coal from the Greymouth Coalfield to meet export specifications. The Northern Opencast area contains a range of native flora and fauna and physical features which make it an environmentally significant area. Mining will totally modify the area, thus an effective rehabilitation scheme is an integral part of the mine plan. Various rehabilitation methods will be used, and wherever possible, the backfilled areas will be rehabilitated so as to resemble the original area as closely as possible.

Jan 1, 1998

Much attention in controlling blast vibrations has been centred on the probability of causing damage to structures in the area adjacent to where blasting is carried out. In most cases these structures are residential properties and the effect of the vibrations on the occupiers has not been studied to any great extent. This paper looks at the sources of disturbance caused by blasting and their psychological effect. A comparison of ground vibration levels for compliance is examined within the framework of structural and human response.

Jan 1, 1998

By J C. Waters

Pseudoclastic hydrothermal alteration textures occur within quenched coherent dykes forming part of a subaqueous dome complex (~4 Ma) onPonza Island, Italy. These textures are similar to those observed in considerably older (~500 Ma) subaqueous volcanic rocks at a number of localities throughout the Mount Read Volcanics in Tasmania and elsewhere in ancient volcanic sequences of this type in Australia. This is significant because the processes of formation, hydrothermal alteration and secondary mineralisation of ancient volcanic sequences may be better understood if we can make comparisons with modern analogues. Observations at Ponza imply that these pseudoclastic alteration features form synvolcanically or immediately after dyke emplacement and lava extrusion. This is compatible with scenarios presented for their formation in ancient sequences in the Mount Read Volcanics, Tasmania.

Jan 1, 1995

Mining and metallurgical processing of gold and base metal ores often results in solid wastes and effluents containing high concentrations of arsenic. In addition, arsenic can be released to the atmosphere from gold roasters and base metal smelters. Speciation of arsenic in roaster products, in a stack sample from a copper smelter, in organic soils impacted by smelter emissions, and in an anaerobic effluent treatment system at a smelter site was determined in order to broaden our understanding of the nature and occurrence of arsenic in a wider range of metallurgical wastes. Micro-XANES spectra obtained from iron oxide particles forming in a gold roaster indicate preferential enrichment of As3+ species in maghemite-rich domains and microlayers. In comparison, haematite-rich iron oxide particles are dominated by As5+ species. It appears that maghemite is retarding oxidation of arsenic and its volatilisation during roasting. Arsenic occurs as both As3+ and As5+ species in a stack sample emitted from a Cu smelter, confined to fine-grained secondary product layers accumulated on the surfaces of spherical Cu particles. This is probably resulting from condensation of As species upon cooling following their volatilisation during the combustion process. Soil samples collected at various distances from the Cu smelter are dominated by As5+ species including monomethylarsonic acid and tetramethylarsonium iodide as the organic arsenic species. The presence of reduced As3+ species highlights the importance of organic material influencing the speciation of arsenic and mineralogical transformations taking place within the soil profile. The XANES spectra indicate that arsenic occurs predominantly as aqueous arsenite species in the anaerobic treatment system, contrary to the conventional thinking of As retention by the formation of secondary sulfides.

Jan 1, 2008

The Influence of Particle Shape in Rock Fracture

Sep 13, 2010

Northern Iron Ltd (NIL) is an Australian listed company that recently brought the historic Sydvaranger open pit Magnetite Mine (the Project) in Northern Norway successfully back into production. NIL made the decision to operate the Project on an owner mining basis, due to limited large scale mining expertise amongst Norwegian mining contractors, a long mine life, a limited range in planned mining rate and to minimise costs. As a new mine operator in a country where labour practices are strictly regulated, there was the desire to reduce the risk associated employing and managing skilled personnel. This was achieved by coupling the purchase of the required mining equipment from the original equipment manufacturer's (OEM) regional dealers with OEM supported Maintenance and Repair Contracts (MARC). This paper examines the process that was followed to implement an owner mining operation in a short time frame; approximately 12 months from the initial requests for quotation to actual delivery of mining equipment to site, and some of the challenges faced. By following a formal and well-tested process, not only was the implementation achieved in the set time frame, but significant value was added through the cost savings achieved in the equipment purchase price and MARC rates that were negotiated through this process.

May 1, 2010