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By V Gau, L Overmeyer, M Kesting

Economically efficient mining processes can be significantly assisted by the implementation of sensor technologies for the detection of materials and boundary layers between materials inside the stratum. These sensors are meant to facilitate the machinery operator and illustrate furthermore the prerequisites in assisting tools towards fully automated mining equipment. Therefore, project æSensory Identification of Material Type and Detection of the InterfacesÆ (SIMT) aims at the integration of ground penetrating radar (GPR) and geoelectric sensor technology by endowing with them a bucket of a bucket wheel excavator. For this reason, a sensor bucket was developed and tested in the Inden Mine of RWE Power AG. The feasibility of integration and deployment of such sensor technology has been proven effective for the conditions of open cast mining. The main focus of current research lies on developing algorithms to analyse the acquired measurement data from the sensors to automatically detect layers and materials. A computer network receives the GPR and geoelectric measurement data as well as the positioning data of the sensor bucket. The positioning data mainly consists of GPS and encoder information, which is merged with the sensor data by using the UTC time stamp. With the aid of consecutive processes the relevant information will be extracted and provided to the user. The aim of SIMT is to replace material identification, traditionally carried out by the operator, by implementing a continuous operating interpretation system in mining equipment based on GPR and geoelectric sensor technology, resulting in more detailed information regarding the working face during an excavation. This detailed information provides an opportunity for efficient planning and controlling of selective mining of natural deposits, such as the process of lignite mining.

Sep 26, 2011

By R McIlwraith, B Breul

"This paper discusses the successful use of bituminous geomembranes (BGMs) in mining applications since their development in 1974. It explains and illustrates the structure of a BGM composite, which is a geomembrane manufactured by impregnating a polyester geotextile with a compound of bitumen, elastomer and filler. Examples of applications of BGMs in the mining industry are also presented in the following contexts.Storage of solid waste: storage of mining waste at mines in Canada heap leach pads in France, Peru, Chile and Turkey at the base of a mining waste landfill in Brazil capping of solid mining waste in Chile and Canada temporary capping of mining stockpiles in Australia (with possible reuse of the BGM for other works).Examples of the application of BGMs for the storage of liquid waste in mining containment reservoirs in Canada, Guatemala and Peru will also be given.For each example given, reasons are supplied that supported the choice of BGMs by the clients and consultants, drawn from the following advantages of the BGM:BGMs have excellent puncture strength, due to the internal polyester reinforcement, as well as excellent ultraviolet resistance. This often eliminates the need for a cushion geotextile or cover soil over the BGM.BGMs have a very long life expectancy, in excess of 300 years, in subsoil conditions (Breul et al, 2004).BGMs can be installed in very harsh climatic conditions. They are suitable for high wind environments as their heavy mass per square metre makes them resistant to wind uplift. The low coefficient of thermal expansion means that BGMs are suitable for installation in mines where very low or very high temperatures are expected. This reduces construction delays and allows for a quicker use of the mining facility.The fact that the BGM can be installed by the mine’s own workforce, after appropriate training from the BGM manufacturer, allows for a more flexible construction sequence on the mine.Ability of the BGM to connect to other materials such as concrete, steel, rock and other geomembranes that may be on the mine site.The technical advantages of a BGM enabled the engineering consultants to prepare solutions for their mining clients that had a lower environmental risk, had a faster completion schedule and were overall a cheaper option than with a polymeric geomembrane.CITATION:Breul, B and McIlwraith, R, 2015. Bituminous geomembranes in mine construction, in Proceedings Tailings and Mine Waste Management for the 21st Century, pp 289–296 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 27, 2015

By B Roache, A Vakili, R Talebi

When a highly anisotropic or weak rock mass is subjected to high-stress conditions, it can lead to large ongoing deformations or squeezing ground conditions. Squeezing ground conditions can impose increased support costs, delays associated with rehabilitation, and disruption to production schedules. Ultimately, in more severe cases, it may result in complete drive closure. Several recent case studies investigated the squeezing mechanism and measures to control squeezing ground in underground mines and also to design appropriate ground support systems. Effective management of squeezing ground conditions requires a sound understanding of the failure mechanism and the driving forces. Once the failure mechanism is understood, the appropriate ground support system should be tailored to specifically manage the critical driving forces that control the squeezing mechanism. Support type, support stiffness, reinforcement length, support density, installation times and mining sequence all have important impact on the effectiveness of the support system. This paper provides a case study at the Ballarat Gold Mine in Australia, where drive squeezing was associated with foliated ground conditions located below 700 m depth. Numerical modelling was used to better understand the failure mechanism and the driving forces that lead to squeezing conditions. The effectiveness of various support types was compared to installed ground support performance. This has provided a credible methodology for assessing and optimising the selection of reinforcement in squeezing ground conditions. CITATION:Talebi, R, Roache, B and Vakili, A, 2018. Understanding and modelling squeezing ground conditions at the Ballarat Gold Mine, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 107–118 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By K J. Lownie, T Rafferty

The in situ testing of mine ventilation fan systems has been a contentious issue for many years. Site testing was generally undertaken by adapting standards that were developed for the laboratory testing of fans using standardised airways. The deficiencies inherent in this practice have been widely recognised by informed practitioners, and this led to the first stand-alone document specifically intended for the in situ testing of large fans (ISO 5802:2001 Industrial fans - Performance testing in situ).This paper describes the structure of the International Standards organisation and the processes that are followed in the course of preparing such a standard.The application of ISO 5802:2001 is briefly outlined together with how test data is assessed for compliance with the suppliers guarantee. This paper must be read in conjunction with ISO 5801:2007, ISO 5802:2001 and ISO 13348:2007.CITATION:Lownie, K J and Rafferty, T, 2013. A review of ISO 5802:2001 industrial fans - performance testing i n situ, in Proceedings The Australian Mine Ventilation Conference , pp 149-154 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 1, 2013

By R G. Barker, A B. Christie

Minerals are necessary for providing almost everything we take for granted in our daily lives including food, shelter, and supplies of energy and water. Minerals are therefore essential for the maintenance and improvement of the standard of living of all New Zealanders.

Jan 1, 1998

By A S. Lund

Optimisation of the underground mining production process benefits from informed decision making during the process of explosive rock fragmentation. Selection of the most appropriate bulk explosive products for underground production blasting is an area of endeavour that offers significant economic upside if correctly and thoroughly undertaken. The explosive selection process is facilitated by a clear understanding of:the physical and detonic properties of the alternative explosive options available; the response of different rock masses to these different explosive options; and the importance of maintaining a clear focus on desirable blast outcomes in order to enhance value creation aspects of the mining production process. The level of understanding of these issues is raised through the application of measurement and modelling technology, quantifying the effects of blast design (and implementation) on process outcomes. Homestake Darlot and DynoConsult applied a range of dynamic blast measurement and outcome modelling techniques in order to explore the relationship between rock properties, explosive properties and mining process efficiencies. A campaign of vibration and explosive Velocity of Detonation (VoD) measurement produced feed data for use in vibration and fragmentation modelling during the extraction of one of the major stoping blocks at Darlot Gold Mine. The paper describes the use of these tools and discusses the understanding gained concerning the limitations and capabilities of, and the reconciliation between, a selection of analysis and modelling approaches.

Jan 1, 2001

By H Stedman

Integrating exploration and operational blastholes into one database significantly enhances geological modelling. Benefits include: improved coal predictions, stronger interpretation of structurally complex areas, detailed mapping of heat affected coal aureoles and additional roof accuracy for blast designs that deliver better coal protection.CITATION:Stedman, H, 2014. Integrating blastholes into exploration data to improve coal recovery and modelling, in Proceedings Ninth International Mining Geology Conference 2014 , pp 237–242 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

How do you initiate closure planning for a mine site that is on the doorstep of a major community without generating the extremes of panic or complacency? That is the question that is faced by Australia's largest gold mine, the Kalgoorlie Consolidated Gold Mines (KCGM) Super Pit in Kalgoorlie-Boulder. KCGM's Community Relations Manager, Danielle van Kampen, will reveal the lengthy closure planning process that is in train to alert yet not alarm the community about the future of the Super Pit and to generate discussion on issues of importance. What will happen to the 'big hole' that generates both mining and tourism dollars for the City of Kalgoorlie-Boulder as its anticipated closure date of 2021 comes closer? How do you communicate a constantly evolving closure date? Although the process may generate more questions than answers, the project will be discussed at length and with the added benefit of independent community recent research in the form of the public 2009 Closure Consultation and the KCGM 2010 Social Impact Assessment. This is an ABSTRACT ONLY no paper was prepared for this presentation.

Jun 1, 2010

By K A. Heasley

The LaModel program was initially developed in 1993, and it is used to model the stresses and displacements in thin tabular deposits such as coal seams. It uses the displacement-discontinuity variation of the boundary-element method with a simplified laminated overburden model and because of this formulation, it is able to quickly and effectively analyse large areas of single- or multiple-seam mines. Over the last couple of decades, LaModel has been used by many mine engineers and researchers for improving pillar designs and mine safety, and it has been continually updated to add functionality and improve its ease of use and accuracy. The present LaModel can calculate seam displacements and overburden, multiple-seam and total seam stresses, pillar safety factors, energy values, roof-bending stresses, fault effects and surface subsidence. It can automatically generate the mine and overburden grids from AutoCAD drawings, and it includes wizards for automatically generating Bieniawski strength coal pillars, easily calibrating the overburden properties to observed abutment stresses and calibrating the gob material to expected gob loading. This paper will present the formulation and features of the modern LaModel program and demonstrate its utility with a multiple-seam case study from the rugged topography in Southern Appalachia.CITATION:Heasley, K A, 2014. LaModel – a program for coalmine modelling, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 409–414 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By B Whiteley, B Gee

The Northside Storage Tunnel is a TBM driven rock tunnel system designed to collect and store sewage from four major storm overflow points along the existing Northern Suburbs Ocean Outfall Sewer. At present, sewage overflows during wet weather are the main source of pollution for Sydney Harbour. The tunnel system comprises a 16 km long by 3.8 m to 6.5 m diameter tunnel from Lane Cove to the North Head Sewage Treatment Plant and a 4 km long by 6.3 m diameter branch tunnel from West Chatswood. The tunnel will have a typical rock cover of about 50 m to 150 m. Most of the tunnel alignment is contained within the Hawkesbury Sandstone Formation which is generally an excellent tunnelling stratum, and offers few geotechnical constraints. However, the tunnel is required to pass beneath incised palaeochannels at Middle Harbour and Manly with each palaeochannel containing about 70 m of sediment.Innovative geotechnical and geophysical investigations were undertaken to examine the tunnel route and characterise the rock beneath the palaeochannels. These investigations have located zones of poor quality rock beneath one palaeochannel in particular, suggesting significant stress relief had taken place in the rock at times of lower sealevel producing structural features indicative of valley bulging. This paper presents the geotechnical model developed for the tunnel, and the models and constraints for tunnelling beneath the palaeochannels.

Jan 1, 1999

More and more coal in Australia is extracted by underground mining methods especially by longwall mining. These methods can be particularly sensitive to relatively small-scale structural discontinuities and variations in roof and floor rock character. Traditionally, information on these features has been obtained through drilling. However, this is an expensive process and its relevance is limited to the immediate neighbourhood of the boreholes. The geological uncertainty remains. Seismic surveying, especially by 3D seismic, is an alternative tool for geological structure delineation with growing credibility. In fact, it is one of the most effective geophysical methods available for identification of geological structures such as faults, folds, washouts, seam splits and thickness changes which are normally associated with potential mining hazards. Seismic data even can be used for stratigraphic identification. The information extracted from seismic data then can be integrated into mine planning and design. In this paper, we demonstrate computer aided interpretation techniques for maximising the information from seismic data and illustrate the ability of seismic reflection methods to resolve localised geological features. Both synthetic and real seismic data obtained in recent 2D and 3D seismic surveys from Australian coal mines will be used. Compared with results obtained with drilling programs, the structural definitions from seismic are of unprecedented quality.

Jan 1, 2002

By J Johansson, E Lund, J Lööw, A Pekkari

Technological development is accelerating in the mining industry (Abrahamsson and Johansson, 2021) and in large parts of the world there is an increased environmental awareness (United Nations, 2015). This can mean both challenges and opportunities. The mining industry has long been criticized for its adverse environmental effects. However, there is now a lively discourse about the role of mining in facilitating the green transition towards sustainable development. Mining is increasingly recognised as a prerequisite for the green transition, by supplying key raw materials to enable, for example, digitisation and batteries for electric vehicles. The green transition not only amplifies the demand for metals and minerals but also intensifies pressure on the mining sector to assume greater responsibility for environmental and societal welfare (Dehaine et al, 2020). New technology, such as digitisation, automation, and remote control, play a crucial role in advancing towards more sustainable mining practices. Despite the expanding role of advanced technology, human involvement will remain important in the extraction process (Rogers et al, 2019), but new technology will change how miners do their work, which in turn will lead to changed competence requirements for miners (Herbert and Hidalgo, 2021) and increased need for further education. Given the significant shift towards sustainable mining, it is important to study how these changes may affect the work, competences, further education and skills of miners as human expertise will continue to be critical in the extraction process. Consequently, there is a need for proactive research to prepare for the inevitable changes and implement measures to support miners through this changeable period to ensure a smooth transition that protects miners’ safety and working environment. This extended abstract explores how new technology will affect the need for further education of miners in the future.

Sep 1, 2024

By Letz H

An investigation of earthquake hazard in Papua New Guinea (PNG) by a yearly extreme magnitude method using the magnitude 7 earthquake record since 1900 shows that the Bougain-ville Island seismic zone is by far the most active, followed by the New Britain and northern mainland PNG regions. Return period for magnitude 7.0 earthquakes occurring in normalized 10,000km2 areas of the Bougainville Island, New Britain, Huon, West Bismarck, North Sepik and Ramu seismic zones is 37, 60, 81, 88, 125 and 125 years respectively. These areas are much more active than the California Seismic Zone 4 region including the San Andreas Fault, which has a normalized magnitude 7.0 return period of 299 years, calcul-ated here by the same method.Only southern PNG, including the Papuan Fold Belt and most of the Bismarck Sea, are less active than California Zone 4. The Papuan Fold Belt is only marginally less active than California Zone 4, but more active than the State of California taken as a whole.

Jan 1, 1994

The seventies was a decade of intensive hydrometallurgical activity, firstly for copper recovery, then uranium, and finally gold. In comminution, semi-autogenous grinding was applied to uranium and gold ores. In leaching there were extensive investigations into pressure and in-situ systems, and into ammonia and chloride leaching processes. Solvent extraction became a major unit operation for copper recovery. New reagents and equipment were introduced. There was a resurgence of ion exchange for uranium as low grade sources were tapped and continuous ion exchange systems developed. Carbon-in-pulp technology came to the fore for gold recovery with the development of desorption and electrowinning systems. Electrowinning was widely applied for copper in conjunction with solvent extraction. There was a continued move to greater mechanisation and higher current density. There were important developments in solid-liquid separation such as high capacity thickeners, belt filters and sand filters. Many of these trends will continue in the eighties. Interesting new developments can be expected.

Jan 1, 1981

By S Hapugoda, Y Tang, L Lu

The steel industry is one of the global leading CO2 emitters, accounting for approximately 7 per cent of global anthropogenic CO2 emissions. In 2022, the world produced 1878.5 Mt of crude steel. About 70.8 per cent of the world’s crude steel was produced by integrated steel mills through the blast furnace and basic oxygen furnace (BF-BOF) process, while the remainder was produced largely by mini mills using electrical arc furnaces (EAF). Compared with gas-based DRI and scrap-based EAF processes, the direct CO2 emissions from the BF-BOF process and the coal based DRI and EAF process are significantly more, as both the processes rely heavily on fossil fuels, such as coke and pulverised coal, to provide energy and reduce iron oxides. Hydrogen is very reactive and reduces iron oxides to metallic iron without generating CO2. Therefore, substitution of hydrogen for fossil fuels in these processes presents a good opportunity to significantly decarbonise the steel industry. This paper will first discuss the thermodynamic and kinetic characteristics of hydrogen and carbothermic reductions of iron oxides and then examine the behaviours of different ore types present in Australia iron ores during hydrogen reduction.

Sep 18, 2023

The Bendigo Goldfield is AustraliaÆs second largest goldfield, having produced 22 million ounces of gold between 1851 and 1954. Development of the modern decline mine, initially for underground exploration and bulk sampling, commenced in 1998. The project is targeting new reefs below and along from historic workings beneath the city of Bendigo. The major technical challenge for the project is the inability to solely use drill core gold assays to estimate the grade of reefs, due to the coarsegrained nature of gold mineralisation, known as the nugget effect. In 2002, a program of bulk sampling commenced, resulting in the development of factors for converting drill hole grades to in situ reef grades. In mid 2006 commercial production commenced following the construction of a 600 000 t/yr processing plant adjacent to the Kangaroo Flat Mine portal, with plant feed being derived from four reefs in the Sheepshead and Deborah lines of reef. In early 2007 it became clear that the initial ore reserves had been overestimated, leading to an immediate change of strategy from production to exploration. A cash conservation program was also put in place. Exploration refocused onto the more historically productive Garden Gully and New Chum lines of reef, whilst a new grade estimation tool based primarily on the visual assessment of drill core was implemented. Immediate exploration success occurred with the discovery of four reefs in the Garden Gully line in early 2007. Successful step-out drilling during the year led to the decision to undertake trial mining in Gill reef. Trial production commenced in June 2008 and includes the processing of discrete ore blocks and the introduction of selective mining techniques. This paper examines the steps that have been taken to refocus exploration and to gain confidence in new exploration results, particularly through the visual grade estimation technique and assessment of trial mining Gill reef on the Garden Gully line. In addition, project factors relating to human skills, community relationships and financial management in a dynamic external environment are also addressed.

Jan 1, 2009

By S S. Kanchibotla, S Morrell

In recent years there has been a growing recognition of the impact that mining practices have on the efficiency of mineral processing operations. Head grade, dilution, particle size distribution and their variability are known to have a significant effect on the throughput and recovery achieved in mineral processing plants. Improved process monitoring and modelling have provided the opportunity to identify and quantify some of these impacts and to define very significant incentives to optimise the overall operation from the mining face through subsequent comminution and processing. The Julius Kruttschnitt Mineral Research Centre has been undertaking research to optimise æMine to MillÆ performance through a major AMIRA research project and through individual research contracts with mining companies. This work has resulted in a broad range of field and laboratory experience in terms of both the challenges and the opportunities encountered when tailoring blasting operations to suit the overall æMine to MillÆ production chain. This paper describes the objectives of æMine to MillÆ blasting to optimise the system of rock breakage involved in the blasting, crushing and SAG milling of hard, brittle ores. The design of such blasts falls outside the conventional envelope of experience for most engineers and requires the consideration of some critical factors if the objectives of such blast are to be met and some of the potential problems are to be avoided. Experience to-date has also found that the quality of implementation is critical to the success of æMine to MillÆ blasts.

Jan 1, 1999

This paper reviews hydrometallurgical processing technology for refractory gold ores, which form an increasing resource stock for gold. The reasons fQr ore refractoriness and pressure, chemical and biooxidation process options are briefly listed. Electrochemical technology, suitable for processing refractory ore is reviewed and some preliminary results for the electrochemical oxidation of slurried arsenopyrite are given.

Jan 1, 1992

By R M. Yanamandra, S K. Tripathy, N Mangadoddy, P Sudikondala, P Ankireddy

Spiral concentrator is one of the most commonly used gravity concentration devices in mineral processing. The particles are classified based on their specific gravity and size. The present work analyses the experimental and numerical investigations of the water flow field, such as fluid depth and free surface primary velocity of two high gravity spiral concentrators at different flow rates. The measurement techniques use a flow depth gauge and flow visualisation technique adapting lycopodium powder as the tracer. Flow features in terms of liquid depth and primary velocity at the free surface of the flow are captured across the trough in two different high gravity spirals. A highspeed motion camera with an imaging frequency of 5400 frames per second and 768 × 768 pixel resolution is utilised to track the tracer particles in the liquid flow on the dark surface background. Further, the two-phase flow is studied numerically on high gravity spirals based on the volume of fluid (VOF) approach utilising the RNG k-ε model and Reynolds Stress Model (RSM) for predicting the fluid flow on trough surfaces such as water depth and free surface primary velocity. The CFD predictions of the flow field for the two spirals are attempted to validate against experimental data. The high gravity spiral concentrators show lower flow depths and free surface primary velocities but steep velocities on the outer trough zone compared to that of low gravity spiral concentrators (conventional coal spirals). Among the computationally tested high gravity spirals, higher pitch and higher secondary slope design shows greater flow characteristics.

Aug 24, 2022

By P Hatherly, A Melkumyan, D Wyman

Chemical species distributions in rock sequences can be modelled using Gaussian processes (GPs) to predict the weight percentage between known data points. This method can be improved by dividing the modelled area into regions of different mineralogy. In the context of many iron ore deposits, marker shales give the initial guidance of where these regions may lie. These shales give rise to distinctive peaks in the natural gamma downhole logs, which are conventionally identified by hand. A GP method has been developed to automate this task.Once the appropriate boundary has been located on the basis of shale occurrences, chemical assays from exploration drill holes are used to find the exact boundaries of interest. These boundaries divide the drill hole stratigraphy into regions of different mineralogy, each of which display their own distinct correlations between the main elements and oxides (Fe, SiO2 and Al2O3). Iron ore shows a negative correlation between Fe and Al2O3, but in banded iron formation (BIF) there is a positive correlation between these species. Similarly, SiO2 and Al2O3 have a positive correlation in the shales and ore but a negative correlation in the BIF. Correlations obtained within ore-, BIF- and shale-dominated regions are therefore better than those obtained using the entire log and can be used to improve the results obtained when modelling.

Sep 26, 2011