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By H Bateman, I Cawrse, G Carnes, S Cawrse

In developing mineral resources, the focus typically centres on the management of identified social and environmental impacts and compliance with regulatory requirements. However, opportunities to protect and enhance the environment and communities are most effective in the planning and design phases. Achieving the objective of integrating sustainability considerations as an element of design decision making requires that the design criteria be technically sound, relevant to the project and applicable to desired design outcomes. This is particularly important for projects employing virtual teaming, where design engineers may be geographically dispersed and are unlikely to be familiar with site specific sustainability challenges and opportunities. This paper documents the approach taken by BHP Billiton to incorporate sustainability principles, objectives and guidelines in design criteria for the Olympic Dam Expansion (ODX) project. It describes the range of inputs used in defining sustainability objectives which interface in a framework that is dynamic and transferable to other mining projects and to engineering design in general. The Sustainability in Design Criteria document distils statutory requirements, corporate standards, lessons learned and leading industry practice into a single coherent framework that supports engineers to approach problem solving as a holistic and integrated exercise with a long term perspective. The framework also serves to improve linkages between internal stakeholders by fostering greater communication, collaboration and innovation to deliver more sustainable outcomes through the design process.

Jan 1, 2009

By Forrest A. Kerr

Introduction During recent years the work of the Geological Survey in northwestern British Columbia has been in the nature of reconnaissance and exploratory mapping, largely for the purpose of gaining knowledge of the potential mineral-producing zones known to occur along the eastern side of the Coast range, and also to gather such data as might facilitate their exploitation. Commencing with fairly detailed mapping in the more accessible parts, the work has been continued and expanded until now an understanding has been gained of the more general features of a continuous section along the range for a distance of about two hundred miles. Geographically, northern British Columbia is more or less isolated. It is cut off from the central part of the Province by a rugged and mountainous country which, except for the telegraph line and a rarely travelled trail along it, is not penetrated by any developed routes or lines of communication. To the west, it is cut off from the Pacific by the Coast range, an extremely rugged area sixty to eighty miles in width which, except along the few navigable rivers cutting across it, cannot be readily traversed. Politically, it is further isolated in this direction by the narrow strip of south-eastern Alaska which borders the coast and extends inland to the axis of the range.

Jan 1, 1931

By Imane Benhamed, Jaouher Diouani, Laurent Cassayre, Florent Bourgeois, Carine Julcour-Lebigue, Université de Carthage

The attrition-leaching process aims at improving leaching performance when formation of passivation layers at the surface of leached particles is a severe limiting factor, as discussed recently by Julcour and coworkers (Julcour et al., 2015). This paper proposes a geochemistry-based modelling scheme for deriving the window of possible operating conditions for the attrition-leaching process to match the properties of the processed ore. The rationale is that the attrition-leaching process maintains the surface of reacting particles in an unpassivated state by continuous mechanical removal of surface leach layers, so that the process reactions can be modelled from thermodynamic equilibria throughout the duration of the process. The strength of the proposed modelling approach is that it bridges the gap between the properties of the ore and the process operating conditions. The present paper exemplifies the proposed process modelling route for derivation of the attrition-leaching process operating conditions in the context of the leaching of silicate ores, matching model predictions against controlled laboratory experiments. It is shown how thermodynamic modelling, when used in conjunction with a solid knowledge of the phases present in the system, can assist with deciding upon suitable process operating conditions. As an example, this firstprinciple modelling approach predicted that steel grinding medium would be converted into siderite (FeCO3) under a wide range of operating conditions, which led to questioning this initial choice of grinding medium for the attrition-leaching process under mineral carbonation conditions. It is emphasised that the same approach could be applied to ores of greater economic significance.

Jan 1, 2016

By Diego Bellato

Production data recorded by special foundation rigs during construction activities at the site are commonly used for quality assurance / quality control procedures and, in particular, to prove that the installed foundation elements comply with the geometrical and quality requirements defined in the design specifications. Parameters such as crowd force, penetration/withdrawal rate, rotational speed etc. are usually presented in reports in the form of depth and/or time profiles. This type of protocols are already standard QA/QC solutions for ground improvement methods like deep soil mixing or jet-grouting, but they are quite rarely applied in combination with other techniques like diaphragm walls or Kelly drilling. In the latter cases, one of the main reasons behind this lack of site documentation is related to the difficulty in interpreting huge amount of data collected during the creation of single elements, which, in some cases, can last several days (not always in a row). In addition, the building sequence is often characterized by many alternated operations involving different movements of the rig and the use of different tools. In this context, the identification of specific construction activities based only on the mere exam of the time profiles of the recorded production parameters is extremely difficult. In this paper, the time profiles of production parameters obtained from a fully-cased Kelly drilling rig employed on a site in Karlsruhe (Germany) have been investigated and compared with a detailed series of activities deduced from a video filmed during installation. Typical time profile patterns associated to specific procedures have been identified by combining the different information available. The outcome of this study helped project engineers to automatize the recognition of activities directly from production data and led to an overall understanding and optimization of the construction process. INTRODUCTION The special foundation industry is characterized by the use of highly sophisticated machinery for the realization of geotechnical systems such as piled rafts, retaining walls and slabs for excavation pits, cut-off walls for levees and embankments or ground improvement solutions. Rigs can vary in size, weight, and power and can be provided with several drilling tools to cope with the different soil conditions (e.g. clay, sand, rock) and the different geometries of the elements to be built at the site (e.g. micro-piles, large- diameter bored piles, diaphragm walls, anchors). Due to the challenging construction procedures, various types of sensors have started to be mounted on the equipment in the last decades to monitor the behavior of some important machine parameters and to inform rig operators about the on-going process and the status of their devices.

Jan 1, 2019

By Estevesson Ferreira Miqueletti

Neste trabalho, tiras de cobre foram laminadas para se obter tubos aletados. As variáveis importantes ao sucesso do projeto foram: a) a temperatura de tratamento térmico e b) a largura da tira. Tiras largas resultaram em pouca união, levando a escolha de tiras menos largas. Temperaturas altas também resultaram em baixa união. A melhor condição foi tiras de 100 mm de largura e 500°C de tratamento térmico.

Aug 16, 2017

By Hai Lin, Renshu Yang, Yongliang Li, Shizheng Fang

With the aim of solving the large deformation problem of surrounding rock in coal mine roadways with a thin sand-mudstone interbed roof, transportation roadway 1603 in Haoyuan Mine was considered. The failure mechanism of surrounding rock was studied through comprehensive on-site investigations, borehole image analysis, mineral composition analysis, and other means. Numerical simulations were performed to determine the influence of roof layer thickness, lateral pressure coefficient, and coal rib strength on the stability of the interbedded roof. The main reasons for support failure and deformation of the roadway are softening and swelling of the sand-mudstone interbed roof upon exposure to water, insufficient support capacity of the roof due to the soft coal rib, an unreasonable support scheme, or poor construction quality, which can reduce the bearing capacity of surrounding rock. Based on our analysis, a control strategy was devised for a thin coal-mudstone interbed roof. The support scheme combines long and short cable support, strengthening of the coal rib to consolidate the roof, and partially shotcrete grout, and was found to improve the overall mechanical strength of surrounding rock and maintain the stability of the thin sand-mudstone interbed roof. The results of the numerical simulations and monitoring data indicated that the proposed support scheme effectively controls the deformation of the surrounding rock of thin sand-mudstone interbed roof of coal mine roadways while maintaining the safety and stability of the surrounding rock and supporting structure.

Dec 12, 2022

By S J. Clarke, C S. Walker

The South West Rail Link (SWRL) project involved construction of a rail line to service new residential areas in south-west Sydney. The 11 km rail line is conveyed through a short tunnel at shallow depth where it crosses beneath the eight lanes of the Hume Highway. The underpass location is one of the most heavily trafficked within Sydney’s motorway network.The New South Wales Roads and Maritime Services (Roads and Maritime), as the owner of the highway asset, had the responsibility of managing the risks to the highway and traffic associated with the tunnelling project from the pretender stage through to completion. This paper considers the primary risks and mitigation measures employed, including geotechnical investigation, and development of appropriate construction constraints and concept design of an extensive real-time survey system to monitor pavement deformation during the tunnel works.The geology comprises fresh Minchinbury Sandstone in the tunnel invert and side walls, and variably weathered Bringelly Shale in the haunch and crown. Few tunnels have been excavated in these rock types in Sydney, and there is little information relating to the in situ stresses and stress-relief deformations in these materials.During tunnel construction the monitoring data indicated unexpected surface heave of up to about 24 mm. A multiparametric back-analysis of the deformation data is presented, which provides information on the deformation mechanisms and key geotechnical parameters, including rock mass modulus and in situ stresses.The approaches and methodologies developed for the SWRL underpass were effective in maintaining the safe operation and traffic capacity of the highway throughout the construction period, and the analysis of the monitoring data provides a useful reference for similar future projects, or projects constructed in similar ground conditions.CITATION:Clarke, S J and Walker, C S, 2014. Deformation mechanisms of the South West Rail Link underpass beneath the Hume Highway, in Proceedings 15th Australasian Tunnelling Conference 2014, pp 631–640 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By J. Daniel Bryant

Deformation processing of rapidly solidified powder alloys presents a technical challenge different in several ways from the processing of ingot based alloys. The metastable phases formed during planar flow casting of aluminum alloy 8009 (FVS0812) must be safe-guarded from high temperature excursions during processing to avoid decomposition; this restriction prohibits liquid phase sintering of particles during consolidation. The development of strong particle-particle adhesion, therefore, relies on the imposition of very large strains during forming operations to insure sufficient mechanical meshing of the aluminum particles and break-up of prior particle oxide boundaries. These strains are generally much greater than those required for metallurgical transformations in ingot based alloys. In an attempt to quantify the deformation required to improve interparticle bonding, the finite element method (FEM) was employed. Preliminary results which predict the metal flow and strain distribution in several workpiece configurations are discussed. These predictions are then correlated to measurements made on experimental subscale forgings. Lastly, experimentally measured quantities which reflect the degree of interparticle bondingg are related back to FEM model predictions.

Jan 1, 1992

By Sadtler, C. B.

IT is generally assumed that in most metals and alloys a given tensile stress produces a given deformation irrespective of the length of time during which the stress is applied. This assumption is justified in most of the important engineering applications of metallic materials; however, in the case of some metals and alloys used or tested at temperatures over or slightly under that at which recrystallization can occur the assumption is not warranted.1 This paper deals with the variations of deformation produced by a constant tensile stress acting for varied lengths of time in the special case of thin aluminum alloy sheet of the duralumin type, which had been subjected to different thermal and mechanical treatments. The material investigated was in the form of a sheet approximately 0.002 in. thick, which had been cold-rolled from a thickness of 0.020 in. It has been found that at a sufficiently high constant tension such material deforms continuously with the elapse of time and that the rate at which this deformation occurs is greatly influenced by the previous thermal and mechanical treatments.

Jan 1, 1927

By J Robinson, L D’Uva

"The Gold Fields group and Gekko Systems have successfully worked together on multiple projects, including at the St Ives, Agnew and Granny Smith operations in Western Australia, and the Damang operations in Ghana, with gravity recovery design, technology installation and optimisation the key driver on each occasion.In 2014, Gold Fields Australia identified an opportunity to challenge the historical thinking at Granny Smith and reassessed the benefit of upfront gravity gold recovery. The historical approach had been to employ gravity on the tailings stream of the carbon-in-pulp (CIP) circuit, recovering sulfide minerals into a concentrate from spiral concentrators for further liberation of gold via a regrind circuit.Gekko was engaged to assess the implementation of a gravity circuit within the grinding area, and to perform a comprehensive gravity recoverable gold test program. Test data was fed into the AMIRA P420 BCC Gravity Model to confirm the gravity recovery potential of the ore, and for process design basis generation. Height, space and capital limitations proved to be a design challenge. However, collaborative learnings throughout the project ensured the design and operation of a reliable and economic gravity gold circuit. Ultimately, the Granny Smith gravity circuit was a success, satisfying all the project objectives and yielding consistent, measurable benefits. On average, the gravity circuit recovers 33 per cent of total gold, resulting in an increase to overall gold recovery by 0.7 per cent.This paper highlights the key project drivers for Gold Fields, and the development of the Granny Smith free gold gravity circuit. It details application of test work and modelling, and the challenges and learnings encountered during the design, installation and commissioning stages. This paper seeks to demonstrate that continuous improvement in a long standing operation can be beneficial to overall circuit flexibility and increased ounce production.Citation:D'Uva, L, Robinson, J and Bell, T, 2016. Defying Gravity - Brownfield Continuous Improvement, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 135–144 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By Leo Ranney

ANY years ago a prospector came to a Nevada town and built himself a shack. Day after day he searched the hills for gold -but he found none. He closed his shack and hurried north, where a strike had been made. Next he tried to trap the flour gold that floats down the Snake River. He panned the black sands along the Oregon coast. He ranged over the mountains and up the gulches of far-off Alaska. At last, broken in health, six years ago he came back to his old home in Nevada. There his shack still stood-nobody wanted it. One day he started a garden in the rocky soil that he owned. His spade turned up a chunk of quartz, and in that quartz were stringers of gold. He had found a rich gold vein, running right under his own house. You gas producers who have hurried to Oklahoma, Louisiana, East Texas, South Texas, West Texas, even to California to drill wildcat holes a mile or two miles deep-why not, like the old gold prospector, have a look in your own back yard? Some of your coal seams contain 20,000,000 cu. ft. of natural gas per acre.

Jan 1, 1943

By C. Özgen Karacan

Methane emissions from the active face areas and from the fractured formations overlying the mined coalbed can affect safety and productivity in longwall mines. Since ventilation alone may not be sufficient to control the methane levels on a longwall operation, gob vent boreholes (GVB), horizontal and vertical drainage boreholes, and their combinations are drilled and used as supplementary methane control measures in many mines. However, in most cases, the types of degasification wellbores chosen are decided based on previous experiences without analyzing the different factors that may affect this decision. This study describes the development of an expert classification system used as a decision tool. It was built using a multilayer perceptron (MLP) type artificial neural network (ANN) structure. The ANN was trained using different geographical locations, longwall operation parameters, and coalbed characteristics as input and was tested to classify the output into four different selections, which are actual degasification designs that US longwall mines utilize. The ANN network selected no degasification, GVB, horizontal and GVB, and horizontal, vertical and GVB options with high accuracy. The results suggest that the model can be used as a decision tool for degasification system selection using site- and mine-specific conditions. Such a model can also be used as a screening tool to decide which degasification design should be investigated in detail with more complex numerical techniques.

Jan 1, 2009

By Donna M. Noel

Bacterial strains have been cultivated from solids previously exposed to cyanide that will tolerate 300 ppm sodium cyanide under anaerobic conditions. In selected solid samples, these bacteria have been shown to reduce the level of cyanide from approximately 300 ppm to essentially zero in about 50 days under anaerobic conditions. Various media were investigated, and the nutrients providing maximal growth were ?established .. Degradation of cyanide in sterilized solids was determined for comparison with degradation obtained in bioactive solids. All experiments were conducted at ambient temperature and initial pH of approximately 10.5.

Jan 1, 1991

By N. Nikolaeva, A. Romashev, T. Aleksandrova

Energetic characteristics identify energy consumption for destruction of prills and kinetic characteristics rate formation of finished size grade in the course of destruction and identify crushing and grinding equipment capacity. And if screen sizing or classification processes are applied in the cycle of ore preparation, then the use of characteristics of separation to size – separating characteristics – is required for theoretical description. Separating characteristics have a lower profile for ore preparation but, nevertheless, they have to be taken into account especially for balance and design calculations of crushing and grinding circuits. In most cases there are impregnations of minerals which vary widely in energy consumption and destruction kinetics and thus polyminerality must be considered as one of priority factor. Raw materials which passed through crushing and grinding processes can be assessed numerically by functions of fractional composition of two types: differential distribution function y ( €) and assay function B( c ) . A set of experiments on grinding of crushed raw materials at different time (up to various sizes) was conducted to analyze effect of grinding size of carbonaceous overburden on function y € and B ( c) as well as to justify the possibility of preconcentration of raw materials at the stage of ore preparation. Analysis of metals distribution per size grades showed that metals are concentrated in size grades of less than 0.315 mm (which is equivalent of cut point for this type of raw material), however, there is no overgrinding and oversludging of material, and enriched product for its further processing can be excluded with the help of classification. The stage of size segregation was tested as a method of preconcentration of raw materials for optimization of ore preparation and further separation.

Jan 1, 2018

By M Bellamy

The DeGrussa copper deposit was discovered by Sandfire Resources in April 2009. Construction of the 1.6 Mt/a concentrator, open pit and underground mining operations commenced in March 2011 with first concentrate production achieved in October 2012. Over the next ten years, DeGrussa grew to include both the DeGrussa and Monty underground mines, establishing itself as one of the world’s premier copper producers with total production of 663 000 t of contained copper by the time the mine closed. Final ore was trucked from Degrussa on 5 October 2022. This paper examines the mine closure experience from both a planning and operational perspective. The paper provides an overview of the site’s mine planning process including the factors involved in determining the end of the mine life and how this was tracked and communicated in the lead up to the end of mining operations. It will also look at some of the specific operational aspects involved in maintaining steady state production all the way through to the last day while facing increasingly challenging conditions. These factors, along with the external factors faced by most of the industry such as labour shortages and COVID related disruptions, contributed to making it an interesting journey to the end of operations at DeGrussa.

Mar 29, 2023

By P Vass, C Butler, J Condon, B Hooper

DeGrussa Copper Mine, resource status 10.2 Mt at 5.7 per cent Cu, 2.1 g/t Au (Sandfire Resources, 2013), commenced concentrate production through its 1.5 Mt/a conventional copper flotation processing plant in September 2012. Geometallurgical assessment during the feasibility study identified potential process-critical ore factors that required further investigation to determine potential impact on processing. Ore characterisation and metallurgical processing performance test work of ore types ensued and subsequently, the first quantitative DeGrussa geometallurgy model was born. Now one year into steady state production, the geometallurgical program has evolved significantly from its infancy and provides valuable insight into ore characterisation and behaviour in the processing plant. This paper details geometallurgical investigations undertaken at DeGrussa to date; from feasibility metallurgical test work through to geometallurgical modelling and management practices, as well as reconciliation between observations at feasibility study level and subsequent observations in production.CITATION:Condon, J, Butler, C, Hooper, B and Vass, P, 2013. DeGrussa Copper Mine, Western Australia - feasibility to first production: a case study in developing a working geometallurgy model from first principles, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 59-66 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

By Yuexin Han, Wenbo Li, Xinran Zhu, Pengchao Li

A multi-stage fluidization magnetization roasting is a promising method to treat limonite ore. The dehydroxylation of limonite ore is a key reaction in the pre-heating stage. In this study, the dehydroxylation mechanism of limonite was studied in a laboratory fluidization roasting reactor. The samples were characterized using in situ X-ray diffraction, Fourier transform infrared spectroscopy, and simultaneous thermogravimetry and differential scanning calorimetry analysis. The phase transformation and kinetics analysis were studied. Results indicated that the dehydroxylation occurred at the temperature of 250–350 °C with the vanish of hydroxyl functional groups (-OH). The dehydroxylation kinetics followed the 2-D diffusion (Jander) reaction model G(α) = [1 − (1 − α)1/2]2, and the calculated activation energy was 113.43 kJ·mol−1. This study is conducive to exploiting limonite ore resources using magnetization roasting technology.

Nov 2, 2023

By D Reid, J Black

The adverse health impacts from diesel particulate matter (DPM) exposure are a well-known global concern. The building evidence has triggered underground mining operations to review existing atmospheric conditions and assess the scale of the challenge faced. South32’s Cannington Mine (Cannington) evaluated the ability to provide a healthy atmosphere from a whole mine approach, taking into account existing preventative controls including: maintenance strategies, fuel quality, mining operations, ventilation provisions, monitoring protocols and effective education and training programs.During the evaluation process, Cannington gave due recognition to the advice and guidance provided in the Queensland Guidance Note 21 (QGN21), the Guidelines of New South Wales’ MDG29 and Mining Industry Advisory Committee (MIAC) of Western Australia. Each of these documents advises a dilution rate of >0.06 m3/s/kW is best for reduction of DPM exposure in underground mines.Achieving the prescribed mine ventilation rate typically results in the need to directly invest significant capital into increasing ventilation infrastructure in order to further dilute contaminants. In today’s economic market of volatile metal prices and increasing pressures to meet regulatory requirements, it can become challenging for established metalliferous operations to create a balance between optimisation of current ventilation infrastructure and capital outlay.In order to obtain and correctly justify the requirements for capital investiture Cannington conducted a ventilation operational analysis for the life-of-operation, identifying the existing air volume envelope was adequate for current and future production rates by optimising existing primary ventilation infrastructure through the implementation of a modified ventilation on demand (VoD) and air conservation system.This process achieved sustainable operating and capital cost reductions without compromising delivery of adequate ventilation to work areas. The process also recognised that engaging mine workers’ ownership of their work areas is crucial to maintaining a technically efficient and operationally robust ventilation system.This paper will concentrate on Cannington’s existing preventative controls, their implementation and their management for the prevention of increased DPM exposure; reducing the risk of both short and long-term health impacts to ‘as low as reasonably achievable’ (ALARA).CITATION:Black, J and Reid, D, 2017. Delivering a healthy atmosphere underground in a cost-conscious environment, in Proceedings Australian Mine Vent Conference 2017, pp 159–168 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By Don Ibana

Supported by the Minerals Council of Australia (MCA) through the Minerals Tertiary Education Council (MTEC), three Australian universities–Curtin University, Murdoch University and the University of Queensland–have formed the Metallurgical Education Partnership (MEP) to jointly develop and deliver an engineering design capstone unit–Metallurgical Process and Plant Design–in their respective undergraduate programs in extractive metallurgy, in order to enhance the students’ educational experience. A unique feature of the program is the close interaction of the students in all three universities and a significant involvement of industry professionals. Now in its sixth year, it is clear that this unit is achieving its objectives

Jan 1, 2014

By A Purchase, C Stacey

The procedure for operation of deluge systems installed in road tunnels is still a subject of debate. The work undertaken in this paper assists in the understanding of the effects of deluge in road tunnels, and thus aims to help inform the development of operational policy. Analysis was undertaken using computational fluid dynamics (CFD) simulations to help explore the deluge interaction with the tunnel ventilation (including smoke exhaust) and combustion products. It was found, for the scenarios considered, that: Deluge activation can decrease the required critical velocity for smoke backlayering, and this in turn can improve the effectiveness of a smoke exhaust system.The dominant parameter for deluge effectiveness is the vehicle configuration, with shielded scenarios (such as a fire in the passenger compartment) showing almost no water reaching the fire. The water delivery rate (5 mm/min versus 10 mm/min) has only a minor effect on the smoke duct damper inlet temperatures and downstream smoke temperatures for small fires (5 MW). For large fires (50 MW) the higher water delivery rate gives slightly improved performance (lower damper inlet temperatures and lower downstream smoke temperatures). A one-dimensional transient tunnel model incorporating different operational and deluge response policies (ie deluge activation times) was developed. It was used to examine the influence of different operational parameters on life safety risk and tunnel damage risk. It was found, for the scenarios considered, that: The life safety risk for different scenarios has a sensitivity to deluge activation policy with the case of delaying the deluge activation for a long time giving the worst outcomes. However, the most critical parameters for life safety risk are operator response time (for all response activities, not just deluge) and the type of fire (configuration, size and growth rate).There is a reduction in risk of tunnel damage when the deluge is activated earlier, although the fire configuration (ie whether or not the seat of the fire can be reached) has the greatest influence on the outcome. It is concluded that the deluge activation policy should be case-dependent. It will depend on the tunnel, the safety systems provided, and most particularly the vehicles involved. The current policy in Australian tunnels is for manual activation of the deluge by the tunnel operator as soon as practical after the fire is confirmed (see also PIARC, 2007). This is a good policy. However, future work may be helpful to improve the skills of operators to make the best judgement as to when deluge should be activated, balancing all risks. This work could include research to further the understanding of deluge and fire in road tunnels, training programs and consideration of historical fire events.

Jan 1, 2008