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By M Grigorescu, S Crimp, J H. Hodgkinson, P Kokic, W Jin

Mines are typically located in remote, inhospitable locations and movement of materials between site, processor and port are often at risk from extreme weather events. Mining companies have recorded multiple supply chain, production and logistics delays caused by climatic events. Recent analyses of extreme temperature and rainfall events (90th and 99th percentile values) for 1960 to 1985 and 1986 highlighted regionalised increases in the frequency and intensity of extremes. The trajectory of this change is likely to be maintained (IPCC, 2014) in regions where increases have occurred historically, suggesting that some parts of the industry may be faced with management challenges beyond current experience (Hodgkinson et al, 2010; Loechel, Hodgkinson and Moffat, 2012). Reliance on historical data to plan for extremes (such as scheduling production downtime to reduce impact) will become increasingly ineffective as the data become less representative of future conditions. Importantly, mine site remediation and closure management need to consider the future climate to ensure rehabilitation is sustainable under changing conditions.Vulnerability assessments and risk-reducing adaptation will become more common as the industry reaches to secure both a mine’s longevity and the industry’s reputation as shareholders and clients become less tolerant of repeated or prolonged interruptions (Hodgkinson, Hobday and Pinkard, 2014). Climate-resilient new mines may be planned using site planning tools combined with knowledge of future climate scenarios. Scenario tools are valuable for developing a gated risk management approach to reducing climate-risk during a mine’s life, through to the rehabilitation process and for managing care and maintenance or closed mines.CITATION:Hodgkinson, J H, Crimp, S, Jin, W, Kokic, P and Grigorescu, M, 2016. Life-of-mine planning tools for a changing climate – intuitive, interrogative, iterative, in Proceedings Life-of-Mine 2016 Conference, pp 71–74 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By B P. Banerjee, D Patra, S Raval

Roof bolts are an essential component of roof support systems in underground mines. They are used to provide structural support to the roof of the mine and prevent it from collapsing. Therefore, it is imperative to perform regular assessments of these roof bolts to avert any hazards. Manual investigations of roof bolts are done by surveyors in underground mines, which is extremely timeconsuming and challenging due to the low-light conditions in underground mines accompanied by stringent mine access rules. To this end, automated recognition of roof bolts in 3D point cloud data obtained through laser scanning in underground mines serves as a potential solution to aid roof bolt monitoring. With the continuous advancements in laser scanning-based 3D data acquisition systems, the feasibility of making such surface estimations from 3D point cloud data has increased severalfold.

Sep 1, 2024

By J Kovacs

Underground development drill and blast practices have generally remained unchanged for decades. Historically, development optimisation has focused mainly on the application of perimeter control products in order to reduce overbreak, and efficiencies in development cycle times to increase advance rates. In today’s environment of ever increasing operating costs and lower ore grades, it has become even more critical to focus on the optimisation of drill and blast in development mining. It is a crucial component in ensuring mining schedules are maintained, but more importantly achieving the objective of getting to the orebody in the shortest possible time.This paper will focus on the development optimisation process used in a trial at Xstrata’s George Fisher Mine in North Queensland. Not only did the trial include the typical optimisation areas of charge loading practices, perimeter control methods, drill design standardisation and quality control processes, it also investigated the significance of delay accuracy with regards to perimeter control and drill design optimisation.One of the key measures of the trial was a comparative analysis between baseline development and development with the staged introduction of optimisation elements using 3D photogrammetry as a validation tool. A detailed cost analysis between the various stages was also a key measurable of the trial.The results of the work undertaken at George Fisher have shown that the accuracy of electronic detonators can produce significant benefits in development blasting. When combined with standard optimisation philosophies a substantial reduction in overbreak, ground support requirements and development cycle times can be achieved, whilst still being able to reduce the overall development operating costs.CITATION:Kovacs, J, 2014. Mine development optimisation – an evolutionary process, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 51–56 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

By C Zhang, I Canbulat, S Saydam, H Yu, H Chen

Natural rocks are frequently exposed to groundwater and complex geological conditions. Environments with water presence are more susceptible to chemical corrosion, which notably affects rock’s micro properties. Generally, the pH of acid mine drainage in hard rock mines can be low to 5, and the pH of quarrying waste deposits can be below 3. With the expanding scope of mining engineering in aquifers and salty areas, chemical corrosion can also caused by different types and concentrations of anions. The anions can significantly affect rock’s mechanical properties. Therefore, it is critical to emphasise the impact of anion and acid on the mechanical and micro characteristics of rock. This paper commences with an introduction to representative corrosive environments. Then the UCS tests are conducted on granite samples corroded by chloride ions and sulfate ions. Anion has negative effects on the strength of granite. The reason is that certain minerals can react and be dissolved by anions and hydrogen ions, such as Al2O3. Furthermore, the scanning electron microscope (SEM) shows that the roughness of the fracture surface increases with the anion concentration. The effect of acid is notably more pronounced than anion on the micro properties of granite. The initiated fissures and pores also increase with the concentration of SO42- and Cl- ions, which is the micro explanation for the impact of anion on rock strength and stability. Subsequently, the permeability of the granite specimens is tested. The reason that granite performs insensitivity to acid and anion is attributed to its low permeability and high content of inactive oxides, such as quartz. To summarise, anionic and acidic conditions can slightly deteriorate the mechanical and micro properties of granite. While SO42- demonstrates a higher level of corrosiveness on granite than Cl-.

Sep 1, 2024

By T Sirinawin, R H. Murfitt, W Shywolup

The Bong Mieu Project lies within the Pre-Palaeozoic Kontum Craton near the southern margin of the regional Phuoc Son û Tam Ky Suture. The Suture and accompanying Truongson Fold Belt of Indosinian age host significant gold and base-metal bearing districts including OlympusÆ other project at Phuoc Son to the west of Bong Mieu and OxianaÆs Sepon project in Laos. The Bong Mieu Project is located some 90 km south of Da Nang and some 30 km south-west of Tam Ky, the provincial capital of Quang Nam province in central Vietnam. The project area is covered by an Investment Licence of some 30 km2 which was granted in 1991 and a mining permit of some 365 ha granted in 1992. Several mesothermal, gold-silver deposits with assigned resources are present on the property. Deposits with assigned resources contain some 615 000 ounces of gold in situ. These are at Ho Gan and Ho Ray which are potentially exploitable by open-pit mining and Nui Kem which is potentially exploitable by underground mining. Newly discovered extensions to the known deposits at Ho Gan, Ho Ray and Nui Kem, and several other new prospects, are currently being investigated by drilling. The Ho Gan mineralisation is of mesothermal, shear and shear breccia quartz vein, as well as intrusive breccia hosted style. Nui Kem mineralisation is of mesothermal, shear and shear breccia quartz vein style. The Ho Ray mineralisation is of skarn (gold-bismuth-tungsten) and lesser quartz vein style. The deposits straddle and flank the east-west trending Bong Mieu Anticline which trends through the central portion of the Investment Licence. In this paper the geology of the deposits, details of resources, results of recent exploration on the Investment Licence and recent engineering and mining studies at Ho Gan are briefly reviewed.

Jan 1, 2004

The Warraua and Mount Poole Inliers form part of a discontinuous series of basement complexes in the northwestern corner of New South Wales. The Inliers comprise mainly clastic sediments of low metamorphic grade (Wonominta Beds) and minor sills, dykes and intrusives, particularly within the Mount Poole lnJier. The Warratta rnlier has received attention due to the occurrence of auriferous quartz-veins where reef mining activities havetaken place.The deformational history of the Warratta and Mount Poole Inljers is characterised by a continuous subhorizontally WSW-ENE directed compression. Deformation was associated with the development of NNW-trending and steeply west-dipping major faults, which bound or biscct the inliers. Chevron folds and a penetrative axial planar cleavage characterise the deformational architecture and document crustal shorterung of at least 40 per cent. In zones adjacent to the major faults and within pelitic and semi-pelitic uruts, a multiple deformational evolution becomes apparent, comprising two events (D1 and D2). Deformational structures considered significant in this study were the result of D1. Tight, northeast-vergent fold patterns FI' and associated axjal plane cleavage SI' and reverse dip-slip movements at major faults indicate early northeast-directed thrusting during D1. This was followed by dextral strike-slip deformation displayed by tight, recumbent folds, en-echelon fold patterns (F2'), a northeast trending crenulation cleavage (52'), and two sets of second order faults, the latter showing high angular relationship to the major faults. A final stage of the deformational history (D2) is represented by WSW-ENE trending kink folds (F2).Auriferous quartz veins, predominantly occurring within pelitic and semi-pelitic units, were generated syntectorucally during the early deformational event (D1) in the course of commencing development of cleavage (S2'). Vein textures point towards vein formation by repeated hydrauJjc fracturing and fracture healing (crack-seal process), and by simple accretionary vein growth. Folded pelite-dominated horizons, considered as low permeability units, are suggested preferential sites where migrating metamorphic Ouids pooled and were trapped, causing high fluid pressure.Hydraulic fracturing and vein precipitation was controlled by lithology and structural constraints such as cleavage.K-Ar dates of approximately 440 Ma (Benambran Orogeny) marking the peak of metamorphism, and coinciding with the development of cleavage S1', also indicate the time of auriferous quartz-vein formation. A period of deformation of at least 30 Ma is proposed for the development of cleavage S1', as constrained by K-Ar dating and the intrusion of a syntectonic granitoid, the Tibooburra Granodiorite.

Jan 1, 1992

Commercial or potentially commercial deposits of coal occur in Australia in strata ranging in age from Permian to Tertiary. The coals of each period tend to show a community of petrographic character and significant differences as compared with coals of other ages. In particular- many of the Permian coals are unusually rich in inertinite whereas the Jurassic and Tertiary coals are typically very rich in vitrinite. The majority of the coals show evidence of deposition in environments subject to relatively minor marine influence. Except for some Tertiary and Permian coals the content of mineral matter tends to be high. Outcrops of coals of bituminous rank appear to be largely restricted to the eastern margin of the Australian continent. In this region vertical rank gradients are generally higher than in the other sedimentary basins and uplift and the removal of cover has occurred to a greater extent. To the west of the Tasman geosyncline, coal of bituminous rank generally occurs at considerable depths (usually in excess of 1 km and in some areas only at depths of over 2 kms), and in most areas coals at shallow depth are of sub-bituminous or brown coal rank. The controls of the distribution of coal type and rank have considerable economic significance and the unusual characteristics of Australian coals, especially with respect to coal type, make the direct application of overseas technology to Australian coals inappropriate.

Jan 1, 1975

By Shiels O. J

The major Permian coal deposits of N.S.W. are in the Sydney-Bowen Basin and associated small deposits occur in structurally isolated areas; a further deposit is present in the Oaklands Basin. - The Sydney-Bowen Basin in New South Wales comprises the sub basins, the Sydney Basin and the Gunnedah Basin. Coal measures in these basins are near the top of the Permian succession and within and below an underlying marine sequence. The coal deposits can be conveniently described in units in which the coal geology is homogeneous. The Clyde Coal Measures and Yarrunga Coal Measures contain no seams of economic significance and occur beneath the marine beds in the south of the Sydney Basin. The Greta Coal Measures are economically significant and represent a brief interlude in the marine sequence in the north of the Sydney Basin and equivalents are present in the east of the Gunnedah Basin. The Tomago Coal Measures crop out above the marine sequence east from the Lochinvar Anticline and dip southeast to uneconomic depths. The Newcastle Coal Measures are historically and economically very important and overlie the Tomago Coal Measures and these measures will continue to be important although future mining will be faced with greater depths. To the west of the Lochinvar Anticline the Singleton Coal Measures, equivalent to the Tomago and Newcastle Coal Measures, crop out. This unit represents the thickest development of coal measures in the State and has a very large potential for both open cut and underground mining. Equivalents of the Singleton Coal Measures, the Black Jack Coal Measures and the Booroomin Group crop out on the east side of the Gunnedah Basin and probably are widespread across the Basin. They have less economic potential than the Singleton Coal Measures. In the southwest of the Gunnedah Basin, Illawarra/Singleton Coal Measures crop out over extensive areas and possibly have a large potential for underground mining under low cover. The Illawarra Coal Measures are exposed along the western margin of the Sydney Basin and thicken as they dip into the Basin across a shelf. The outcrop area is currently mined and the shelf has considerable potential for future mining. The highest rank coals in the State are in the Illawarra Coal Measures in the south of the Sydney Basin. The deepest coal mining is in this area and its continuing success is of great importance to the future exploitation of the resources of the Basin. The Tomago, Newcastle, Singleton and Illawarra Coal Measures extend into and meet in the central area of the Sydney Basin but they are under thick cover and are not considered to be economic at present. Permian coal measures occur in isolated areas in the New England Fold Belt and have limited economic potential. The Oaklands Basin in the south of the State contains a large reserve of low rank coal.

Jan 1, 1975

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

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

Sep 1, 2024

By N LaBranche

The resurgence of Silicosis and Coal Worker’s Pneumoconiosis (CWP) in coalmines has placed the spotlight back on the management of worker exposure to particulate matter across all mining sectors (Coal Workers Pneumoconiosis Select Committee, 2017). There already exists a substantial body of knowledge on particulate matter and its impacts upon human health (National Academies of Sciences, Engineering, and Medicine, 2018). The contribution of silica to respiratory disease is well known and there is a growing concern for exposure to diesel particulate matter. However, it is also clear that there are major gaps in our understanding. In part, those gaps relate to the contribution to adverse health effects of mineralogical constituents in the dust (LaBranche et al, 2021a). It is also becoming evident that the size and shape of the particulate matter can affect its potential impact on human health.The University of Queensland has developed a methodology for characterising respirable and inhalable dust samples using scanning electron microscopy. Multiple samples from numerous mining operations have already been analysed using the UQ methodology. The process has been successful in showing the variety of mineralogica lcomponents and particle size distributions presentin various areas of the mines.

Oct 12, 2022

By A Roudnev, P Loderer

Mineral froth pumping utilising centrifugal slurry pumps is a major engineering challenge for both the end users and pump manufacturers. The traditional approach has been to oversize the pump for pumping mineral froth. New horizontal slurry froth pump designs offer opportunities to improve froth pumping capability of mineral froth with challenging (high) Froth Volume Factor while maintaining high efficiency, long wear life and stable pumping performance.CITATION:Loderer, P and Roudnev, A, 2018. A reliable solution for pumping mineral froth with challenging froth volume, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 291–296 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By W G. Rowley

The Fortescue Metals Group story began in 2003 with a vision to establish an infrastructure project that would connect the stranded iron ore deposits of the Pilbara region of Western Australia with the steel mills of Asia. Following exploration successes in the Chichester Ranges using their new exploration model, Fortescue established significant iron ore resources at Cloudbreak and Christmas Creek during 2004 and 2005. By May 2006 the definitive feasibility study for mine, rail and port was completed, many of the key government approvals had been obtained, product development and market acceptance were complete and 1.07 Bt of total proved plus probable iron ore reserves were defined to support a 20 year mine life from the Cloudbreak and Christmas Creek deposits. Project construction commenced in September 2006 following a successful $3.2 billion capital raising. By April 2008, the mine and processing plant at Cloudbreak were completed along with the Herb Elliott port facility at Port Hedland and 256 km of heavy haul railroad linking the mine with the port. Mining of overburden commenced at Cloudbreak in late 2007 and by 15 May 2008 the first shipment of iron ore had departed for China. In the first 12 months of operation total shipments amounted to 24.6 M wet metric tonnes with weighted mean composition of 58.9 per cent Fe (64.4 per cent Fe calcined), 4.3 per cent SiO2, 2.0 per cent Al2O3 and 0.047 per cent P. Exactly 3.5 years between the Cloudbreak discovery hole and commercial production. The project success depended on many technical breakthroughs including a new exploration model, application of the surface miner as the main mining production unit, design of a new marketable fines product called æRocket FinesÆ, a highly efficient ædesandÆ flow sheet for upgrading of 2.4 per cent alumina run-of-mine to 1.9 per cent alumina Rocket Fines, 40 t axle loads for the heavy haul railway and a high capacity-highly automated port facility.

Jan 1, 2009

By A S. Kurilko

For mines located in the cryolitic zone, thermal conditions are an important factor for all kinds of mining works, especially for ventilation of workings. In the present paper, some models of mine air heat transfer considering air distribution in a net of mine workings are developed. A combined solution is suggested for heat transfer and air distribution problems in mine workings and other underground structures located in the cryolitic zone. A software package is also presented for calculating temperature conditions in an underground refrigeration plant and for optimisation of ventilation conditions. This software uses a special 3D mathematical model to describe heat transfer in a freezing chamber between surrounding rock massif and stored product as well as between atmospheric air and the daylight surface of rock massif. A problem requiring strengthening of a backfill material and its thermal interaction with surrounding rocks during underground deposit mining by horizontal layers in conditions of the cryolitic zone is also discussed. The developed program takes into account cement consumption, geometrical dimensions of workings filled and a sequence of deposit mining.

Jan 1, 2005

In terms of tunnelling the mining industry is generally thought of as the crude cousin of the civil construction industry. Mining has tended to concentrate on speed and flexibility rather than the high standards required in civil tunnelling. Historically this difference has been based on the belief that such high standards were not required by the mining industry, they would slow down the development of the project and as a result increase the costs and extend the time period between start up and a positive cashflow.For civil works the construction of a tunnel is the project, for mining the construction of declines, crosscuts and drives are merely the means of accessing the orebody so that the real work can begin û MINING. Extraction of ore is the core business of most mining companies û it is what pays the bills.Though most mining companies have the equipment, the people, the knowledge and the ability to excavate tunnels, in the past mining companies did not appear to put the same energy into their tunnelling operations as they put into improving their ore extraction operations. In the past decade this appears to have changed, many mining companies now realise how important the correct excavation of a decline is to the success of the overall mining operation. They began to recognise that there were cost benefits to be gained in using the correct development techniques without overly sacrificing the benefits of speed and flexibility.This recognition also coincided with the growth of underground contractors whose predominant work was primary development (declines and ore access crosscuts and drives). The contractors again had the same knowledge, the same people, and similar equipment but their focus was different from that of the mining company û the contractors were focused on the development of the mine, the excavation of declines, crosscuts and drives. These deliverables were the contractorsÆ core business û itÆs what paid the bills.

Jan 1, 1999

By D Cai, E Baafi

Various enabling technologies and systems have recently been introduced in the mining industry. Such systems include miner-bolters with concurrent cutting and bolting, employment of two shuttle cars, adoption of self drilling bolts and utilisation of continuous haulage or monorail systems. The paper discusses how Flexsim discrete event simulation models were used to assess how these proposed mining systems can best be used to achieve and sustain high roadway development rates of 10 m per operating hour for 20 h/day.

Sep 26, 2011

By L. Gilbert

Recent changes to environmental legislation and trends in the environmental regulation of mining in the Northern Territory are being driven by (among other factors) Federal Government policies and international agreements on the environment. These trends are discussed and the expected application of the NT Water Quality Management Strategy (based on the National Water Quality Objectives) over the next few years is examined with respect to mine environmental management practices. Some of the potential conflicts and changes in approach which may develop are identified and examples discussed. Proactive means of integrating trends in environmental legislation with mine planning and waste management are discussed.

Jan 1, 1994

Exploration and mining title administration in the Northern Territory has changed dramatically over the last 20 years. These changes have occurred due to legislative amendments, technological developments, and the changing face of the mining industry. The first legislation to control mining in the Northern Territory was the Northern Territory Gold Mining Act (1873) of South Australia. In 1911, control of the Northern Territory was passed from South Australia to the Commonwealth. As a result of the mining boom which followed the discovery of gold in Tennant Creek in 1932, the Commonwealth passed the Mining Ordinance of 1939. This legislation was amended 39 times and stayed in force until July 1982, when the self-governing Northern Territory passed the Mining Act 1980. This Act is still in force and is continuously under review. The first computerised mining titles system, REGIS, was created in 1984/85 and was, to all intents and purposes, just a computerised index. Various modifications ensued, and in 1989 the Titles Database was unveiled. The database has developed to be one of the most sophisticated yet user-friendly mining titles databases in Australia. In excess of 50 companies have access to the database from their own offices. Work continues on its development and fine-tuning. The paper outlines the development of the database since inception.

Jan 1, 1994

By Wyborn L, Giddings J. W, Plumb K. A

The McArthur, Balma (new name) and Habgood Groups are thick (up to 4.5 km) correlative sequences of shallow water evaporitic carbonates, mudstones and sandstones that are exposed largely within the Batten, and southern and northern Walker Fault Zones (Batten and Walker Troughs) of the McArthur Basin respectively. Recent re-mapping of the Walker Fault Zone has provided data for refined stratigraphic correlations between these groups. Two significant hiatuses are now recognised within the Balma Group (base of Vaughton Siltstone and base of Yarrawirrie Formation) and these may represent tectonically-generated sequence boundaries which may correlate with similar local hiatuses within the McArthur Group such as at the base of the Teena Dolomite and Lynott Formation respectively.

Jan 1, 1994

International tenders for contract mining opportunities require the Contractor to make an assessment of risk for an operation with a life span of up to twenty-five years usually based on data made available by the Client. This paper seeks to address how the Contractor assesses the data and quantifies the risks associated with the project. The areas of risk are common to most projects, but in the--Lontractor's case, risk assessment is carried out on the Client's data base and within a compressed time frame of usually less than six months. Incorporation of that risk assessment into the contract documentation is also discussed. Practical examples are given in a number of areas.

Jan 1, 1986

By R B. Wanty

Historically, most investigations of biogeochemical cycling in acid rock drainage systems involved synoptic sampling over longer time periods (one sample per week or month) or intensive time series studies over a few hours or days. However, many important episodic loading events, such as seasonal meltwater and storm events occur on timescales that are rarely observed by these traditional sampling approaches. Monitoring these transient processes, which may contribute the bulk of the annual metal loading, is essential for accurate assessment in acid rock drainage areas. Recent work also has demonstrated dramatic diel (24 hour cycle) variations in trace metal concentrations in response to diel changes in temperature, pH, oxygen, and photochemical cycling (Brick and Moore, 1996; Nimick et al, in prep). To characterise a system that may respond to diel, seasonal, and episodic events, a monitoring program must sample at a frequency that captures the details of these major forcing events. We developed two novel instruments, the Zn-DigiScan and the DigiSampler to examine low and high frequency temporal changes in acid rock drainage areas. The Zn-DigiScan is a battery powered real time in situ chemical analyser designed for long-term deployments with hourly analyses of Zn. Stream physical parameters (temperature, conductivity, dissolved oxygen, pH, turbidity, etc) were measured every 15 minutes with a water quality sonde. The DigiSampler was developed for the long-term daily sampling of biogeochemically active elements and can take either discrete samples or samples integrated over 24 hours. The DigiSampler collects 2 ml samples in a Teflon coil which are separated by 0.2 ml nitrogen bubbles. The sample coil is returned to lab and the 2 ml samples are diluted 1:10 and analysed for trace metals by ICP-MS. Initial results from a three-day deployment at Fisher Creek, MT, USA have successfully demonstrated the ability of the Zn-DigiScan to record Zn concentrations at levels below 100 ¦g/L. Zinc concentrations measured at 30 minute intervals in Fisher Creek showed a diel cycle with low values of ~25 ¦g/L in the late afternoon and increasing to ~60 ¦g/L by early morning. Zn concentrations were inversely related to temperature and pH, suggesting that temperature and pH dependent adsorption was the main factor controlling diel Zn fluctuations. Initial deployment of the DigiSampler also was successful, revealing diel cycles in Zn, Cu, and Mn. Comparison of trace metal samples collected by the DigiSampler showed good agreement with samples collected by an Isco automated water sampler, demonstrating that the DigiSampler can collect clean samples for trace metal analysis at the low ¦g/L range.

Jan 1, 2003