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By D J. Brake

The risk from fire remains one of the most serious of underground mine disaster scenarios. The impacts of mine fires on the underground ventilation system and the production of toxic gases have been difficult to model and therefore assessments have relied largely on empirical data, historical precedent and subjective opinions. Underground fire modelling software has had limited availability and been technically challenging and time consuming to use especially for routine mine investigations. There has also been no well-accepted set of assumptions for fire modelling in mines, which has resulted in a lack of confidence in adopting its use more widely. This paper describes modelling of three critical fire scenarios in underground hard rock mines: a fire (LHD) in an underground diesel refuelling facility, a fire in an underground explosives magazine and a fire on an underground ore transport conveyor. Modelling was undertaken using VentsimÆs VentFIREÖ fire simulation module. It describes the basis of design, the key assumptions, the methodology used and provides examples of the outputs, conclusions and recommendations. It reviews the impacts of these fires on egress and entrapment strategies in the mine. Some general principles regarding improvements to ventilation circuit design based on this analysis are also recommended. Whilst the fire scenarios were based on actual case studies, they have been disguised for this paper.CITATION:Brake, D J, 2013. Fire modelling in underground mines using Ventsim Visual VentFIRE software, in Proceedings The Australian Mine Ventilation Conference , pp 265-276 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 1, 2013

The Telfer Underground sublevel cave (SLC) Operation is located approximately 850 m below surface. The cave was designed to propagate through an old decline which was initially used to monitor the cave. There was a requirement to install air blast plugs at two locations in the old decline in order to isolate any potential air-blasts from the active workings in the event of the rock mass collapsing into the cavity. There was a further requirement for an air-blast plug in another section of the mine where there was a risk of the cave intersecting an old workshop and providing an air-blast pathway through an abandoned incline. The design criteria for the plugs was that they should withstand the design air blast loading, be free draining, cost effective and easily constructed with the mining expertise available on site. A plug consisting of grouted mullock was considered robust and least challenging to construct. For the purpose of estimation of maximum air pressure on plugs, it is supposed as a worst case that the rock above a cave falls as an airtight piston onto the top of a muck pile, forcing air into it and also mine workings intersected by the cave. Airflow through the muck pile is governed by Ergun's equation for turbulent flow. In a time-stepping integration scheme, transient air pressures and velocities are calculated according to equations of thermodynamics, in the cave and at intervals along intersected drives by means of a finite difference spatial discretisation. The ability of plugs to withstand computed pressures is assessed by finite element elastoplastic analysis. This paper outlines the rationale for potential air blast loading, calculation of transient air pressures, plug design and analysis of plug behaviour. The plug construction method is also discussed.

Nov 25, 2010

By M D. Sussman

A large number of countries in the world now have some regulation for labelling the presence of genetically modified organisms (GMO) in food. For the last ten years, ISO/TC 34/SC 16 has been providing methods, guidelines and requirements concerning the evaluation of molecular biomarkers including GMOs. This activity makes sure that stakeholders on all sides of commercial transactions are satisfied and their marketing or regulatory needs are met. Developing and maintaining a transparent, science-based environment for users of horizontal methods for molecular biomarker analysis is a high priority. Sampling and analysis of molecular biomarkers has become critically important for food and agricultural organisations developing, producing, distributing and selling genetically engineered, non-genetically engineered, identity preserved and/or organic crops and their derived products and preventing their respective destructive diseases. To aid in international harmonisation, a new work item proposal to develop an ISO type A management system standard (MSS) for organisations including laboratories using molecular biomarker analysis and sampling has been submitted to ISO/TC 34/SC 16. The purpose of this MSS is ensuring that determination of the presence, absence or quantification of a particular biomarker with a relationship to a product quality determinant, a marketing claim, a regulation or a plant pathogen is carried out under a suitable quality assurance / quality control system. This MSS will provide an overarching system to apply and manage molecular biomarker analysis and sampling for any organisation large, medium or small in a private, government or academic setting.CITATION:Sussman, M D, 2017. ISO/TC 34/SC 16 horizontal methods for molecular biomarker analysis – molecular biomarker analysis and sampling management system, in Proceedings Eighth World Conference on Sampling and Blending , pp 295–302 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By M-A Van Ende, N Kumar, I-H Jung

In order to utilise the powerful thermodynamic databases for process simulations, a concept called Effective Equilibrium Reaction Zone (EERZ) was introduced to couple thermodynamic database calculations and reaction kinetics. Using the EERZ concept, many process simulation models for steelmaking processes have been developed within the FactSage steelmaking consortium. After validation of the simulation results by comparing with plant data, the simulation models have been applied to improve plant operations. Several success stories of the improvement of real steelmaking operations are shared. A new user-friendly FactProSim software developed for building process simulations is introduced.

Aug 21, 2024

By I Cameron

Simulation is increasingly being used to analyse mineral processing operations and explore efficiency options. Engineers that use simulation are rightly concerned with the quality and applicability of the underlying models. However, many of these models have a significant empirical component, and the best structure for this component may not be apparent. There is an opportunity to improve the quality and application range of these models by exploring potential structures for this empirical element. One approach to this problem is the use of structural optimisation, which is a formalisation of the model development process. This method searches through a family or hyper-structure of candidate models for a model that is optimal with respect to some measure of model quality. This method has been applied to the modelling of an industrial flotation circuit. The result was a model that was a significant improvement over a number of standard models reported in the literature. Structural optimisation provides a method to compare potential models in a systematic and efficient way, and hence to improve the structure of process models.

Jan 1, 1998

By R Norris, M Dunne

Mining and mineral processing is expected by society and obliged by law to operate in an environmentally friendly fashion, minimising the impact on and avoiding damage to the environment. Substantial efforts by the industry, as well as by process and equipment designers have resulted in many innovative developments, which show that operating in an environmentally responsible manner can be achieved in a cost-effective way. This paper showcases five emerging equipment best practices in industry including installation examples. Flip-flow screening machines are proven worldwide in the dry classification of coal and other minerals, reducing the size of beneficiation plants whilst reducing energy, water demand and media consumption. They also allow the screening of wet/sticky materials not able to be sized using conventional screens. The belt press filter is a small fraction of the operating and capital cost of alternative dry tailings technologies. This gives operators who must dry their tailings a competitive advantage and makes such ægreenÆ operations much more sustainable. The filtercake is disposed with other plant rejects, eliminating the need for tailings dams to be constructed and thus also often increasing mine reserves. Mining applications include coal tailings, sand tailings, sinter plant waste and power station fly ash. Screen-scroll and vibrating centrifuges are widely used in the coal, potash and salt industries to dewater the product to low surface moistures. Inclined plate Lamella separators are used for toxic water clarification and/or sludge thickening in many downstream metal industries with the underflow often dewatered in a belt filter press. Such low cost, high capacity thickeners could also be used instead of conventional thickeners at smaller mines. The simple and reliable continuous washing upward flow (CWUF) sand filters have been used for treatment of waste water from coal preparation plants and steel works as well as in the worldwide production of potable water. The filtered waste water from mining processes can then either be reused or discharged from site. Other installations include cleaning mine water to prevent the blocking of dust suppression spray nozzles.

Jan 1, 2006

By X Zhang, B McFadzean, C T. O’Connor, S Pikinini

The Platreef in South Africa contains one of the world’s largest reserves of platinum group elements. One of the major platinum group minerals (PGM) components in this ore is sperrylite (PtAs₂), which has been found to be slow floating compared to the other PGMs. In a study aimed at determining the reasons for the poor floatability of sperrylite and to improve its recovery, tests were carried out to determine the interactions of the mineral with a range of standard and novel collectors. Microflotation tests were carried out to determine the hydrophobicity of the minerals before and after adsorption of collectors. In addition, experiments were carried out to determine the enthalpy and extent of collector adsorption on the minerals and to investigate electrochemical interactions between sperrylite and selected standard collectors. The results indicated that poor collector adsorption was the major cause for the poor floatability of sperrylite. Sperrylite had both poor natural (14.5 per cent) floatability and collector-induced flotation recoveries, the highest recovery of 26 per cent being observed using PNBX collector at pH 9. Moreover, the rest potential tests showed that the interaction of sperrylite with standard collectors such as xanthates was poor. The decrease in potential after the addition of the standard collectors ranged from 7.9 mV to 24.9 mV under alkaline conditions. Furthermore, sperrylite rest potentials remained unchanged with a change in pH from basic to acidic, indicating its resistance to surface alteration. Surface alteration of the minerals is key for the chemisorption of collectors to take place on the mineral surface. This was further emphasised by flotation recoveries at low pH, where only certain collectors responded positively to a decrease in pH and these were shown to have undergone a structural change. This work has highlighted the difficulties associated with sperrylite flotation and provides some direction for future research.

Aug 24, 2022

Gravity gold recovery has been practiced for thousands of years, making it one of the oldest forms of mineral processing. Gold is 19 times heavier than water although the barren rock is generally only 2.7 times heavier. Any potential gold ore needs to be characterised to assess its amenability to a gravity recoverable gold (GRG) process based on well planned and executed test work. Scale up considerations need to be considered in designing a gravity circuit. The economic impact of a gravity circuit should be justified based on the installed cost and likely benefits. Maximising gravity gold recovery results in a faster cash flow, lower operating cost per ounce and higher overall gold recoveries compared to the several weeks required to recover gold adsorbed onto carbon. The advent of centrifugal concentrators such as the Knelson and Falcon, coupled with intensive leaching of concentrates (ILR), has revolutionised gravity gold circuit designs. Considerations associated with the sizing of the centrifugal machines and the percentage of the circulating load (bleed) that should be processed is discussed in this paper. The trends with gravity circuit layout, engineering, as well as optimum dumping cycles, are important areas which require close consideration. Key aspects of these are presented in this paper. There are a number of circuit configurations to be considered, including the integration of different gravity concentrators. Other gravity process design considerations such as fewer modules, the effect of equipment size and enhancement of process efficiency using preconcentration, together with factors that affect OPEX and CAPEX are addressed. Practical considerations of maintenance, security from theft, minimisation of risk and water balance considerations are discussed using different equipment and circuit configurations. The trend towards using gravity recovery in flotation plants is also reviewed. A number of examples are cited and good design aspects highlighted.

Aug 1, 2010

By D Giles, A C. Bailey

In the first 20 years of the 21st century, just over 20 per cent of Australian mineral exploration expenditure was dedicated to iron ore, totalling >A$8 billion and >30 million metres of drilling (Australian Bureau of Statistics, 2021). Improvements in the cost, efficiency, safety, reliability and data quality of drilling have the potential to deliver significant productivity improvements, increasing the probability of discovery and reducing the time from discovery to mining. Currently in its third year of research, Mineral Exploration Cooperative Research Centre (MinEx CRC) is focused on a new set of exploration tools and new ways to deploy those tools which recognise the fundamental importance of collecting quantity and quality data from the subsurface, to enable exploration success for all minerals, including iron ore. MinEx CRC is focused on developing more productive, safer and environmentally friendly drilling methods to discover and drill-out deposits. This includes pioneering work on Coil Tube (CT) drilling technology and innovations in Diamond and Reverse Circulation (RC) drilling techniques aimed at improved drilling optimisation and automation. In parallel, MinEx is developing new technologies for collecting data whilst drilling. This is being undertaken in four separate industry-led projects utilising geophysical, seismic, downhole analytical and 3-dimensional (3D) modelling improvements. A National Drilling Initiative (NDI) is also underway, with two drilling programs completed in 2020. The NDI is a world-first collaboration of Geological Surveys, researchers and industry, which undertakes drilling in under-explored areas of potential mineral wealth in Australia and provides a test-bed for new mineral exploration technologies.

Nov 8, 2021

By F Diaz, G Hovestadt, B Friedrich, D Latacz, M Sommerfeld

The metallurgical sector significantly contributes to the global carbon footprint and encounters the challenge of developing more sustainable production methods. This study introduces novel approaches aimed at reducing CO2 emissions within the industrial sector, some of which have been developed up to the demonstration scale. In two case studies, urban waste from the agricultural sector (corn, olives, coconut etc) and waste electrical or electronic equipment (WEEE) recycling residues (shredder light fractions (SLF)) were subjected to thermal treatment. The resulting materials were then used as substitutes for conventional fossil-based reducing agents in both the copper and ferroalloy industries. Furthermore, hydrogen was employed at different scales to assess its efficacy as a reducing agent for recovering metal oxides from fayalitic copper slags. Our findings reveal promising prospects and defined specific challenges for the integration of these alternative reducing agents in the industry. The synergistic use of pyrolysed SLF, bio-coke, and hydrogen presents a viable pathway to significantly diminish CO2 emissions while simultaneously improving the sustainability of the metallurgical sector.

Jun 19, 2024

By R Godard, J Gantumur, F Prince, C Pascoe

Resolution Copper Mining LLC (RCML) is one of the largest undeveloped high-grade porphyry copper-molybdenum deposits in the world, with an orebody at depths of approximately 2000 m beneath post-mineralisation cover. With a vision to develop a large-scale, low-cost operating mine, the project is designed as a micropanel cave with an advanced undercut.In September 2014, RCML began a study focusing on identifying and selecting the best production cases to eventually reach full production (120 kt/d). To achieve this, a methodology was developed that allows the fast evaluation of a large number of production schedules.Dassault Systèmes GEOVIA was commissioned to enhance the Footprint Finder program for batch scheduling panel cave production. The tonnage and grade schedules produced by Footprint Finder were compared to schedules developed using personal computing block caving (PCBC™). The inputs to Footprint Finder were then adjusted to achieve a reasonable correlation with the PCBC™ schedules.The enhanced Footprint Finder program was used to batch-process nearly 54 000 schedules using 20 elevations, 17 shutoff grades, four heights of draw, two different copper grades (modelled and upside), two layout refinements within the existing footprint and a variety of production ramp-up rates to 120 kt/d. The study team developed processes to analyse large amounts of data, to assist in selecting a matrix of the best schedules for detailed assessment using PCBC™. Three hundred PCBC™ schedules were developed.The detailed trade-offs between the scenarios is currently underway with promising results. This paper outlines the methodology used in evaluating the numerous alternatives.CITATION:Gantumur, J, Godard, R, Prince, F and Pascoe, C, 2016. Development and evaluation processes of cave production schedules for the Resolution copper project, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 59–64 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

CONTENTSThe significance of values givenINTRODUCTIONTHE ORE1. DATA SECURED FROM THE MILLING PLANT AS OPERATING BETWEEN 1938 AND 1942(a) Mill Recoveries(b) Mill Flow Sheet(c) Scheelite-Garnet Association(d) Detailed Examination of Mill Performance during 1942Crushing UnitsCoarse Rolls DischargeFine Rolls DischargeFeed to Huntington MillsFinal Ground ProductProduction of -200-mesh Scheelite SlimeSummary of Information on Crushing and Grinding Circuit(e) Detailed Examination of Mill Performance During 1942Concentrating UnitsLocation and Nature of Scheelite LossesSize Distribution of Scheelite LossesDistributor Spigot ProductsSummary of Information on Concentration Circuit(f) Detailed Examination of Mill Performance During 1942 Gravity Plant Feed2. EXAMINATION OF MINE SAMPLES TAKEN DURING 1942(a) Introduction(b) Nature of the Ore(c) Sampling of Mill Feed(d) Testing Technique(e) Minus 1/8-inch Ores-Naturally Broken Fractions(f) Recoveries from Plus 1/8-inch Fractions-Crushed to Minus 1/8-lnch(g) Probable Recoveries Obtainable from Weathered Ores140 Contour120 Contour90 Contour(h) Examination of an Ore Sample from the 90-foot Adit(i) Run-of-Mine Ore(j) Evidence of Maximum Sizes of Scheelfte Present in Run-of- Mine Ore(k) Summary of Information on Liberation and Recovery from the Ores as Mined in 1942 and from the Mill Samples

Jan 1, 1944

By A Kamaraj, M Mohanasundaram, R Kumar, P Tikare

This study presents a comprehensive thermodynamic optimisation and sustainability analysis of the secondary copper smelting process for Waste Printed Circuit Board (WPCB) recycling. The study investigates various scenarios with different proportions of WPCB in the input stream, ranging from 0 per cent to 100 per cent. Through thermodynamic modelling using FactSage™ version 8.1, the optimisation process is conducted in three stages. The results of the thermodynamic modelling indicate that the best-case scenario for WPCB recycling is achieved with a 40 per cent proportion of WPCB in the input stream. This case exhibits a maximum copper recovery of 99.93 per cent while minimising the formation of other waste. In addition to the thermodynamic analyses, environmental factors such as the carbon emission index and resource utilisation efficiency are studied. The 40 per cent WPCB recycling case exhibits a resource utilisation efficiency of 93.055 per cent and a carbon emission rate of 0.133. The present investigation highlights the significant benefits of a 40 per cent WPCB recycling scenario through a secondary copper smelting process in terms of base metal recovery and energy efficiency, thus emphasising its potential for sustainable PCB waste management and resource utilisation.

Aug 21, 2024

By P Standish

Qualitative risk assessment methods are not well suited to considering complex systems and potential interactions of new technology. As part of supporting tier one mining organisations and international industry groups, the author and colleagues have innovated processes to help provide better solutions to sites/companies considering a move to implementing proximity detection and collision avoidance systems. The process identifies required operating states for the system. By applying a combination of research and team-based analyses, a rigorous identification of credible failure modes which could cause these states to be lost, is identified. Finally, required business inputs, expressed in practical terms are distilled from regulator, industry, organisation and site in a way which clearly addresses the failure modes and so retain the required operating states. These business inputs identify improvements for site arrangements (EMESRT levels 1 to 7) before identifying functional requirements for technological collision avoidance solutions (levels 8 for advisory and 9 for autonomous). The paper presents a case study synthesised from multiple sites analyses and will provide guidance on where to find additional resources to assist in making the best possible transition to better equipment and road network solutions.

Jun 22, 2022

By P Ring, B Cooper, C Carr, G Laing

The Nova Ni-Cu-Co Operation, located in the Fraser Range of Western Australia, commenced commercial production in July 2017 only five years after discovery. Owned by Independence Group NL (IGO), the operation has successfully ramped up over an accelerated schedule and currently deploying leading technologies. This paper begins with a description of the Nova Operation, and its journey to achieve full production in such a short time frame. It includes discussions on development and production design, selection of fixed plant infrastructure, and the features challenges of running a low-pressure primary ventilation circuit. The paper also discusses key technologies that have improved overall safety for the underground workforce, and improved operational efficiencies. Investigations continue into the implementation of further technological applications for safety and productivity enhancements. This paper also discusses the findings from a study into transitioning from a diesel to an all-electric underground mining fleet, based on a review of Nova if it were to be developed today with the current EV offerings. The study indicates compelling savings will be available to future mines when considering development design, project schedule, capital outlay and operational savings, and the ‘next Nova’ is expected to be all electric.

Mar 15, 2021

By B Stewart

It has long been recognised that knowledge of the conditions existing in a mine after an incident is essential in deciding whether to deploy responders as part of the incident recovery process. Applying this knowledge in a structured manner to the assessment and the acceptability of the risks likely to be faced by those teams during response activities before authorising their deployment is an onerous task incumbent upon the person controlling the incident response. The Mine Event Management System (MEMS) provides structure and coordination in the management of mine events. It assists with the skills and knowledge for incident control teams to effectively manage any emergency or non-emergency event, be it large or small. In cases where multiple organisations are involved, the MEMS promotes effective joint operations through the use of common terminology and structure to provide seamless communication between agencies at all operational levels. The SQL-based software developed by Queensland Mines Rescue Service (QMRS) assists decision-makers to make considered options; it does not make decisions for you. When set-up, it allows the information that already exists within a mine’s Safety Health Management System that is relevant to the incident to be accessed and considered rapidly within the pressured environment of an emergency. Additionally, the incident specific questions contained within MEMS focuses the management team on gathering and assessing information relevant to the incident as it progresses. The software’s event log can be utilised as an auditable document for post incident investigation. The MEMS provides a process to properly consider the adequacy of the information available upon which decisions have to be made, to consider and acknowledge the hazards of the environments within or adjacent to which responders will need to work and to acknowledge and authorise the entry of responders into or to remain within a mine either during or post an incident occurring, once an acceptable level of risk is achieved.

Apr 16, 2024

By M Scoble

This paper addresses the importance of collaborative approaches to resolving future mining challenges. It attempts to provide some insight into understanding the theory, measurement, mapping and management of collaboration. This is related to the design and planning for successful research and educational initiatives. Reference is made to Canadian and global case studies and personal experiences.

Nov 22, 2011

A hidden asset in most exploration and mining activities is data. Common practice involves the spending of large amounts of money to discover, define and prove the viability of a mining project. Some organisations have used operations research analysis and internal costing methods to allocate a value to their data and to compare the costs of data maintenance to other more tangible activities like plant and equipment maintenance. Those organisations, which do not undertake such an analysis often, have little knowledge or understanding of the extent and the worth of their data. Often the organisations lack of knowledge and understanding of the data is indicated by their failure to fully exploit or realise their opportunities. The focus of this paper is to discuss new technologies that optimise the management and security of collected and derived data. The technologies discussed are components of the software systems acQuire and MineSight.

Jan 1, 1999

By T Isaksson, J Anderson

The procurement process for underground construction contracts, in particular those contacts involving tunnel boring machines (TBMs), is subject to many complex and inter-related variables, including national and local politics, public policy, community involvement and media attention û as well as strict environmental and legal requirements. Other restrictions include the time available to adequately investigate geotechnical conditions and viable technical options to determine the best construction methodologies û including selection of tunnel boring machine characteristics and, those construction means and methods suitable for the specific geotechnical and environmental conditions. The latter are, most often, quite imperfectly understood. æGetting it rightÆ implies that an optimal configuration û of machine type, characteristics and associated methodologies û can be found and successfully implemented for a particular project. æFrom the beginningÆ implies that the lack of time issue can be successfully resolved. Within an international context this paper highlights a number of issues of concern which relate to tunnel procurement systems and the ways in which certain key processes are managed during planning, design and construction. The authors argue that there is considerable room for improvement in the way tunnelling projects are undertaken and an approach is discussed which has the potential for substantial gains in cost and schedule and reduction of risk. Savings, however, may only be fully realised if the new methods can be fully implemented by all parties involved. This, we believe, will require the rejection of ætraditionalÆ forms of management and procurement with associated changes in the roles and responsibilities of owner, engineer and contractor. Additionally, risk identification, assessment and mitigation are essential cost and schedule control process which have, to this point, been underutilised by the underground construction industry.

Jan 1, 1999

By S Wellink, D Chalmers, D Adermann, C Martin

The practice of recording blasts for quality control purposes has been conducted for several decades. However, at the low frame rates of a standard video camera, essential data is frequently missed as it occurs when the shutter is closed between frames.The use of high-speed video for the research, development and monitoring of the performance of blasting procedures is a well proven but under-utilised practice.The recent development of low cost, easy to use high-speed digital cameras and user friendly software can deliver a capability into mine management as a day-to-day production tool that can greatly improve blasting performance and reduce costs.Digital high-speed video and image analysis software can accurately quantify each blast. Analysis of the images can facilitate the identification of causes of variance from design, geology changes, errors in blast practice and areas of poor performance. The use of high-speed video greatly enhances the audit and review processes so that future blast design can be quickly and appropriately modified to deliver improved blasting performance and reduced costs.The three videos demonstrate the differences between standard video and high-speed video and the detail that can be obtained from them. These videos of open cut blasts can be used to identify blast performance variances. Capturing images at 1000 frames per second allows the analysis on a millisecond timescale where detonator timings, fragmentation, venting, fume generation and flyrock can be accurately identified.CITATION:Adermann, D, Chalmers, D, Martin, C and Wellink, S, 2015. High-speed video – an essential blasting tool, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 471–476 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015