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The excavator selection process is quite complex due to the large number of influencing factors, many of these are variable and difficult to accurately define. The majority of mining companies prepare a tender of general specifications and suppliers will then match a product to those specifications. The mining company will then evaluate the tenders on the basis of the best available deal. In this paper, the importance of open pit excavator selection in terms of its impact on operating costs is analysed and discussed. A rigorous process for selection is then outlined.

Jan 1, 2003

Vertical retreat open stoping (VROS) is a variation of sublevel open stoping (SLOS) that has been introduced at Cannington to minimise the influence of subvertical geological structures during stope extraction. The first application of VROS is described, where structures within the stope resulted in a change in firing sequence and the extraction of two complete sublevels in a single blast. The use of electronic detonators is critical to the success of VROS and their application is described. Numerous benefits of using VROS have been identified and are described. To date, eight stopes have been successfully mined using VROS. In addition to the first application of VROS, two further case studies are described.

Jan 1, 2005

By Reichman J. P

Extensive use is made of a small scale computer (IBM 1130), in the calculations of ore reserves for Western Mining Corporation's nickel mine at Kambalda, W.A. All surface drilling data such as assays, density and location information, are stored on disk files at the Company's Technical Computing Centre at Perth, W.A. The computer is used to search through the data, select significant ore intersections, calculate the area of influence of each intersection and perform the necessary calculations to arrive at an estimate of the ore reserve. Comparing the computer-assisted ore reserve calculation with an entirely manual operation, it is estimated that a saving of 40 percent in time is achieved together with

Jan 1, 1973

The 3.5 million tones per annum Enterprise mine is the newest underground copper mine at Mount Isa in northern Australia. At a depth of up to 2000 metres, it is the hottest and deepest mine in Australia. In situ rock temperatures sometimes exceed 60¦C requiring the installation of substantial amount of refrigeration to provide safe working conditions for mine workers. The latest refrigeration project at the mine, R67, required the design and installation of the worldÆs largest bulk air cooler and AustraliaÆs largest chilled water plant. The plant is mounted on the surface of the mine and provides 25 MW of refrigeration to cool some 580 kg/sec of ambient air to 11.4¦C. This is equivalent to the production of 6300 tonnes of ice per day. The plant was designed for high availability, as any downtime would result in substantial production losses to MIM, and also had the potential to quickly result in unsafe levels of heat stress within the underground workplaces. The bulk air cooler has been designed for a capacity of 34 MW(R), the expected ultimate carrying capacity of the 7 m vertical intake shaft. Being located well inside the tropics, technical issues such as control of thermal pulldown required special consideration. Also, the bulk air cooler had to be designed to handle whatever demand for fresh air was imposed by the mine below, with over 100 per cent variations in airflow expected, and without loss of thermal efficiency. A substantial program of risk assessment and HAZOP studies was used to protect underground miners from leaks of ammonia into the air or water circuits. Fully automatic control systems result in a totally unmanned plant that is supervised remotely. To improve efficiency, the plant is controlled by the outlet air temperature from the bulk air cooler û the first in the world to be controlled in this fashion. Engineering solutions to address environmental considerations were incorporated at the design stage through features such as the use of ammonia (a greenhouse-friendly gas) as the refrigerant, zero atmospheric discharge and a wastewater collection and re-use system.

Jan 1, 2002

The magnesite deposits near Young, N.S.W., occur in decomposed serpentine rock below a soil. and alluvial cover. They show considerable variation in both quality and depth which greatly hampers mining operations. Seismic refraction techniques afford methods of conducting detailed and reconnaissance surveys which yield a depth and velocity analysis of the serpentine/magnesite refractor. The measured seismic velocities may be used as an index of the presence and quality of the deposits. The Seismic Timer which was used in the test surveys is a simplified seismograph which makes use of seismic reciprocity by replacing the conventional seismic shotpoints with geophone stations and the conventional geophone stations with impact points of a sledge hammer. Thi,s enables the use of detailed seismic refraction techniques which yield the depth and velocity analysis of the refractor.INTRODUCTIONThe magnesite deposits near Young, N.S.W., were produced by a process of leaching and enrichment of magnesium in serpentine rock. The magnesite occurs in nodular form emplaced in decomposed rock at shallow depths below soil and alluvium. The depth ranges from close to the surface down to some tens of feet. The deposits are patchy and show considerable variation in both quality and depth, giving riseto considerable difficulties in mining operations.Due to the thorough leaching of the surface material, geochemical tests carried out so far have not proved satisfactory for locating the pockets of magnesite enrichment.It was decided to test the application of detailed shallow seismic refraction methods to the investigation of both the depth and quality of the deposits. The tests were carried out...

Jan 1, 1962

By Young DJ

Gold mineralisation at the Hamata prospect is related to a series of stacked pyrite and quartz-pyrite veins associated with a number of shears which strike N to NE and dip E. Mineralisation is contained entirely within the Morobe Granodiorite close to the intersection of the Upper Watut Fault and some younger NE to SW striking faults. The prospect was originally detected in 1987 by a regional stream sediment sampling programme. Subsequent mapping and sampling outlined an anomalous zone approximately 900m long by 300m wide. Drill testing has indicated a resource of 46Mt at 0.9 g/t Au.

Jan 1, 1991

By H Barrie, L Ameglio

"Current methods for acid rock drainage (ARD) mitigation revolve around insulation of the waste from oxygen in the atmosphere with water and dry (soils and liners) covers. Both are of limited effectiveness and present significant drawbacks. Furthermore, while they reduce oxygen influx, they reduce but do not prevent ARD.The inert gas mixture (IGM) technology has been designed to overcome the deficiencies of gas transfer into tailings and waste rock materials across the surface and instead block oxidation by controlling the transfer of oxygen from the atmosphere. Inert gas is injected into the mine waste at low flow rates and the positive but low flow purges the oxygen that tends to diffuse into the sulfide waste across the surface. The positive flow of IGM compensates for inward oxygen diffusion and creates a pressure drop across the cover layer preventing inward diffusion of oxygen and, hence, acid generation.The IGM processes are evaluated in this paper: theoretically, with a review of the theory of ARD and the current state of knowledge about the performance of notably dry covers as atmospheric oxygen barriers via models to predict the performance of the IGM technique practically, with a bench-scaled experiment.The results demonstrate the effectiveness of IGM to prevent oxidation of sulfide minerals and ARD in waste rock. The laboratory experiments further identified key variables to be used to monitor performance and control efficiency of IGM, which is now awaiting field-scale application.The IGM technology is a patented process by Terraquest Technologies Ltd (Canada) in USA, Canada and Australia. The IGM technology can be cost-effectively manufactured on-site with commercially available compressors and gas filtration membranes. It is predicted that low-cost covers can then be utilised with IGM, which in turn lowers the overall capital costs of ARD mitigation.CITATION:Ameglio, L and Barrie, H, 2015. Acid rock drainage prevention using inert gas mixture technology, in Proceedings Tailings and Mine Waste Management for the 21st Century, pp 85–96 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 27, 2015

By S Maryati

Surface mining activities disturb large areas, produce great sediment loads and tend to be a source of water pollution if they are not managed properly. Coal mining in Indonesia has a very high risk of soil erosion because the coal mining areas are generally located in tropical areas with a high average of rainfall (4000 - 6000 mm/year) and use surface mining methods. The main factors affecting erosion risk are climate, soil type, topography, vegetation cover and management factors. Thus, the monitoring of erosion risk in mining areas is very important due to the characteristics of coal mining in Indonesia. The objective of this research is to determine the ability of satellite images (remote sensing data) and geographic information systems (GIS) to provide an accurate and up to date spatial database for the monitoring of erosion risk in surface coal mining areas using the Universal Soil Loss Equation (USLE) method.The erosion risk analysis and spatial data processing are generated by the ArcGIS 9.3 software and need several data, namely: an erosivity map, erodibility map, a slope map, vegetation index map and land management or land cover map. The erosivity map is derived from the rainfall data, whereas the erodibility map is derived from the soil map. The slope map is derived from the SRTM-DEM (Shuttle Radar Topography Mission-Digital Elevation Model) and processed using 3D analyst tools. Furthermore, the vegetation index map and land cover map are derived from a satellite image using digital image processing techniques.This preliminary study produced results that show soil erosion monitoring, which is integrated with remote sensing and GIS technologies, has great potential for producing accurate, advance, and low cost erosion risk maps in coal mining areas. This map is very important for getting spatial distributions of the erosion and useful for developing erosion management plans.

Nov 22, 2011

By J Hutchings

An essential component to the management of any process is the measurement of key parameters, used to monitor, control, and provide the feedback necessary for improvement. This paper discusses how data collection and analysis can provide a better understanding of the blasting process, as well as additional control and improved outcomes.The drill and blast process involves the generation and use of information at a number of levels. Comparison of historical parameters and results provides a starting point for the development of ongoing blast designs and a baseline against which future results can be compared. The collection of data during implementation provides a quality assurance/quality control (QA/QC) function where potential defects (such as under-drilled or over-charged holes) can be rectified prior to firing. Actual quantities and production rates allow the development of realistic plans and schedules, rather than using inaccurate estimates and targets that lead to unscheduled changes to equipment paths. Over?the past several years there have been a number of technological advances in data collection technology. Drill monitoring instrumentation on blasthole drills provides location information and feedback on rock properties as drilling occurs. Hand held ‘data logger’ technology has also overcome the challenges of working on the bench, such that blasthole measurements can be collected and forwarded directly to the explosive truck. Mine sites are becoming wireless network-enabled allowing the seamless data transfer from the field back to the office, in near real time, as that information is collected. Great strides have also been made in the development of drill and blast software systems which are more user friendly, and yet provide far greater capability to manage the quantity of data generated. The blasting process is critical to the overall mining process and the delivery of a successful blast outcome requires that the blasting process be ‘in control’. The measurement of key parameters can provide the data with which to measure and maintain control of blasting, and allows the validation of performance improvement measures and identification of improvement opportunities.

Nov 8, 2011

It is well documented that drill and blast outcomes affect the downstream mining processes of loading, hauling, crushing and grinding but it can also significantly impact on mine profitability via dilution, recovery percentage, lump generation (iron ore), fines generation (coal, iron ore), coal loss and final wall stability. Drill and blast must therefore be optimised to improve the overall profitability via positively impacting on productivity and saleable product generation. It is however, difficult to achieve this because of the complexity of the number of parameters that must be integrated and managed across the entire mine value chain, ie the concept of æMine to MillÆ. This paper highlights, via a simple case study, the need to have a mineÆs drill and blast system both in control (so that it is predictable to a high degree) and with minimal variability (so the design actually makes it into the field). This type of management control is essential prior to optimisation work being undertaken. The æTeam ApproachÆ is discussed to illustrate the methodology of achieving drill and blast optimisation. A case study is presented to illustrate the potential benefits of this approach which in this mine represented a 27 per cent reduction in powder factor with the downstream functions achieving higher productivity with the same or reduced maintenance costs. It is essential for Australian mineÆs to implement the appropriate management strategies and experienced personnel placement to ensure that their mineÆs drill and blast system is correctly managed to facilitate the optimisation of profit. Without this, the Australian mining sector will become increasingly uncompetitive.

Jan 1, 1999

By S Walters

The emerging discipline of ‘geometallurgy’ is not new but is becoming increasingly recognised as a discrete and high-value activity. Geometallurgy involves a quantified and spatially constrained approach to ore characterisation in terms of relationships to critical processing performance behaviours. A key outcome is enhanced economic optimisation of mining and improved risk management tools.Industry recognition of the need for large-scale, integrated research to support this emerging area resulted in commencement of a major ongoing initiative in mid-2005. The AMIRA International P843 ‘GeMIII’ project (Geometallurgical Mapping and Mine Modelling) is a cross-discipline collaboration involving a number of world-class research organisations supported by over 20 industry sponsors.The project is delivering integrated tools and methods which link intrinsic rock characteristics to prediction of mineral processing performance. These indices must be capable of spatial distribution in 3D resource models and incorporation into mine planning and optimisation. A key aspect is provision of new cost-effective tools and methods which can provide the large numbers of measured and estimated data points required to undertake effective modelling and spatial distribution. The integrated methodology and enabling technologies being developed through the ongoing AMIRA GeMIII project are outlined, together with implications for supporting industry best practice.

Sep 5, 2011

By Kandemir H, Stafford G

The Croydon Gold Mine is located in northwest Queensland and is a joint venture between Central Coast Exploration N.L. and Pancontinental Mining Ltd. The mining operation commenced in 1987 and consists of satellite open pit mines feeding a central Carbon-In-Pulp gold Treatment Plant. The gold mineralisation is hosted by quartz veins within the Croydon Volcanic Group and the Esmeralda Granite, a cogenetic igneous suite of Middle Proterozoic age. The mineralisation comprises gold and silver with associated basemetals. The gold and silver electrum occurs as extremely fine free grains. The gold distribution is heterogenous occuring across the full vein width, or restricted to the footwall or hangingwall. The average mineral resource grade is 3.5 g/t. The deposits are all hard rock and mining is carried out by drill and blast technique. All mining activity is carried out by a mining contractor. Mining is by a selective mining method which entails the drilling, blasting and extraction of the hangingwall waste prior to orebody extraction.

Jan 1, 1989

By S C. Barrie

St BarbaraÆs Marvel Loch operations have successfully used longhole open stoping as the primary mining method for a number of years. A transition to Core and Shell mining was implemented in 2009 to recover substantial ore grade resources remaining in sill and rib pillars. The transition to core and shell for the Exhibition lode required continuous waste filling of created voids and thus the removal of the crown pillar at the base of the Exhibition pit by blasting. Access to the top of pillar was denied as the pit was partially rock filled with waste rock from underground development.Beyond the technical challenges of the blasting project, a simple and transparent risk management process was developed to ensure appropriate controls and mitigating strategies were in place to minimise risk to personnel during the pillar removal process.Although failure of the crown pillar was anticipated but with the actual timing unknown, on 25 December 2011 the crown pillar yielded during normal mine operations. Engineered and isolation controls in place at the time were of a sufficiently high standard to ensure limited exposure of the underground workforce and minimal damage to mine infrastructure. Successful risk management through implementation of appropriate controls during the project lifecycle of two years and three months proved to be fundamental to the safe removal of the crown pillar.CITATION:Barrie, S C, 2012. Successful risk management through project life cycle for removal of the crown pillar at the Marvel Loch Underground Mine, in Proceedings International Mine Management 2012, pp 125-134 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

By W Mackinnon

Coal mining operations require the expenditure of appreciable start up and working capital in order to produce saleable coal for domestic or export markets. The competitive nature of the coal business restricts margins, and so it is imperative that downside risks, in terms of production outcomes, are minimised. The major risks identified for a coal mining operation, aside from sales volumes and coal price, are generally thought to be confined to the geology of the deposit and the mining process. However, the impact of product quality and yield can be very significant. If product coal is inferior to projections, then it will need to be sold at a discounted price and this can dramatically impact on margins. Equally, if yield is five to ten per cent less than planned, then this will have a huge effect on profitability. This paper will look at issues relating to in situ moisture and density, resource quality evaluation, modelling of washability and dilution, and simulation techniques, and how best practice approaches can be incorporated into mine planning and feasibility studies. Risks are best modelled and understood by adopting a detailed approach that is fully documented and auditable. This is particularly needed for multi-seam and multi-product operations. Once a well defined systematic approach is established the potential risks can be evaluated by testing different scenarios, carrying out sensitivity analyses, variability modelling and examining extreme operating conditions. These have been discussed in the paper, along with some related issues such as the cost of quick fixes and the value of spending a little more in the coal preparation area.

Jan 1, 2003

By H Utama, hi, A Suw

PT. Indo Muro Kencana (PT.IMK) is gold and silver mine located in Central Kalimantan province, Indonesia. Mining activities in PT.IMK is conducted in Bantian pit area by applying surface mining method and using combination of excavator and hauler (articulated dump truck and rigid haul truck) as the transportation for ore to the crushing plant and waste material to the waste dump. Current blasting practice is ore-waste blasting. Ore-waste blasting is the term where the ore and waste rock are blasted in the same blasting process. Blasting is conducted by using nonel initiation system. By multiple pits operation, monthly powder factor is varied from 0.23 kg/t to 0.27 kg/t. Emulsion blend with density 1.15 g/cc is used as bulk explosive. At this stage, the concept of geoblast is proposed as an engineering tool for Drill and Blast engineering practice in PT.IMK. In addition, there is a need to maintain rock fragmentation by blasting, to maintain monthly powder factor, and to maintain excavator’s productivity. Next, the concept of scaled depth of burial (Chiappetta and Treleven, 1997) and the concept of blastability index (Lilly, 1986) are proposed as geoblast’s tools to improve blasting practice in PT.IMK. It is expected that rock fragmentation by blasting, explosive consumption and excavator’s productivity will be maintained by integration of geoblast and drill and blast engineering. Furthermore, the objective of this paper is to integrate geoblast and drill and blast engineering in order to create an engineering guideline in PT.IMK. Additionally, blasting trials with air decking application is proposed in order to support the geoblast’s improvement. It is planned that these blasting trials will be conducted in 2022. In conclusion, it can be seen that integration of geoblast and D&B engineering in PT.IMK is relevant to improve current drill and blast current practice and applicable to maintain rock fragmentation by blasting.

Nov 29, 2022

The Que River and Hellyer polymetallic massive sulphide ore bodies are located 3 kilometres apart in the Cambrian Mount Read volcanics of Western Tasmania. Both deposits are classic examples of the Kuroko volcanogenic style. Base and precious metal rich hydrothermal solutions rose through a deep fracture system and vented on the sea floor, causing sulphides to accumu- late in adjacent topographic lows. Together the preproduction geological resource is approximately 23 million tonnes at greater than 18% zinc plus lead, with economically significant silver and gold. Exploration by Aberfoyle in the Mount Read volcanics com- menced in 1970. Que River was discovered in 1973 following a comprehensive data review, a regional stream geochemical survey and a helicopter-borne electromagnetic survey. Production began in 1981, and the mine is currently producing 300,000 tonnes per year. The ore is sold to the Electrolytic Zinc Company of Aus- tralasia Ltd mill at Rosebery. Ten years of extensive geological mapping, soil geochemistry, and induced polarisation, combined with continual study of the Que River orebody and its host rocks, formed a strong frame- work for the discovery of the Hellyer deposit, which was found as a result of drilling .a subtle time domain electromagnetic anomaly in 1983. Hellyer is currently being mined at a rate of 250,000 tonnes per year, with the ore being concentrated at Aber- foyle's converted Cleveland tin mill. Treatment of 1 million tonnes per year will begin in early 1989 at a new mill located near the Hellyer site.

Jan 1, 1988

The Australian Constitution specifies certain powers of the Commonwealth Government to be used in its capacity as the national government. Certain of these broad powers result in the Com- monwealth having a facility to play an important part in the development of the mining industry. The State Governments, however, by virtue of their wide powers to regulate matters within the boundaries of a particular State, are more directly involved in the day to day administration and standards of activities of mining operations. In this respect the Common- wealth has something of a dual role because of its "State-like" responsibilities for the mainland Terri- tories. The components of the role that the Common- wealth Government discharges in relation to the mining industry are qualified to varying extents at particular times by the political persuasion of the Government. In absolute terms the components are as follows. 1. Economic management. The Commonwealth's fiscal and monetary policies have an important effect on industry as well as on State finances. In particular, the taxation regime employed by the Commonwealth Government is of direct importance to economic decision-makers in the mining industry. 2. International matters. International trade and commodity matters are, more and more, becoming an everyday part of the conduct of a nation's foreign affairs. 3. Exports. The Commonwealth Government, via the constitutional powers over overseas trade, have exercised varying degrees of control over mineral exports to achieve particular objectives. 4. Foreign capital and investment. Australia in general, and the mining industry in particular, is and will continue to be a net importer of capital. There appears to be bipartisan political agreement in Australia that foreign investment policy must be enunciated to ensure that investors. are in no doubt that Australia welcomes beneficial investment and technology from overseas. 5. Environment and Aborigines. Governments, both Commonwealth and State, have in recent years become more involved in these areas in response to their interpretations of community aspirations. 6. Energy. Access to assured supplies of energy is now viewed, by Governments worldwide, as a desirable asset to ensure the well-being of a nation's people and industries.

Jan 1, 1978

By F Shi, G Ballantyne, K Runge

There has been minimal innovation in the methods used to process an ore over the last 50 years. Productivity increases have largely resulted in increased equipment size without implementation of parallel improvements in technology. Complex orebodies of the future will need mining operations to adopt new technologies and techniques to make future ore treatment economically viable. Three emerging technologies, namely high voltage pulse (HVP) pretreatment, fine screening and the HydroFloat<sub>TM</sub> coarse particle flotation cell will be presented in this paper and the potential benefits that may result if they are adopted in mineral processing circuits will be outlined. The barriers that must be overcome before they can be adopted by industry with confidence will also be discussed. CITATION: Runge, K, Shi, F and Ballantyne, G, 2018. New technologies that will potentially enable processing of complex orebodies, in Proceedings Complex Orebodies Conference 2018, pp 126–129 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By Dawson CF

About 17% of the world's present day oil supplies comes from wells drilled in the continental shelf of some 28 countries. The demand for oil is increasing each year and is expected to quintuple in the next decade. In the same period, the demand for gas will climb to at least 20 times its present rate. In the next decade, the percentage of oil and gas obtained from offshore is expected to rise to nearly half the world's consumption. The offshore oil industry is currently striving to achieve new technological advances in the field of deep ocean operations, especially in face of adverse seas. While the emphasis was put on drilling vessels for exploration, the industry was slow in developing effective offshore construction vessels. Until a year ago, construction vessels were but large barges with construction equipment mounted on their decks. These vessels all shared the same severe limitation: When the sea exceeds a five-foot wave height (and in some cases as little as three feet) the conventional construction barge is forced to suspend operations. In face of an oncoming storm they must run for shelter. Their utilization, therefore, is limited and in rough weather areas, such as the North Sea or the Bass Strait is lower than 50%.

Jan 1, 1970

By Gregg PEH, Stewart RB

Reclamation field trials commenced in 1985, two years before the granting of the Mining Licence. The level of pasture production on varying soil depths (0 cm, 5 cm, 15 cm and 25 cm) overlying both tailings and oxidised waste overburden was assessed. After seven years, the rate of increase of N, C, P and S, losses of S and P and pH changes were investigated on the plots where grass seed was sown into bare tailings. It was determined that on these plots it would take approximately 24 years to reach the original carbon and nitrogen levels at the mine site.

Jan 1, 1995