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On the face of it this is an easily answered question. Modern technology and life as we know it today would be impossible without industrial minerals and the responsible utilisation of mineral resources is essential for the economic wellbeing of the nation. The quarrying industry supplies a high percentage of the industrial minerals used in New Zealand and our role therefore, is to ensure a constant supply of high quality roading and concrete aggregates so that society and the community as a whole can develop. We must do this in a manner which causes the least possible disruption to members of the community, which efficiently utilises all the valuable resources, which causes as little pollution as possible and last but by no means least, creates realistic profit for the operator. It is only by achieving a reasonable profit that we are able to continue in business and therefore play our part in the development of the country. Unfortunately, quarries have a poor image and are not generally popular, as on the whole, they are noisy, dirty and dusty and attract large trucks which create traffic problems. Judging by the amount of restrictive legislation with which we have to comply today, not even government or the local authorities want quarries which presents the industry with some serious problems, some of which will be outlined in this paper.

Jan 1, 1978

By E Mare

Recent highly publicised incidences of disastrous containment failures, none more pertinent than the 2019 iron ore tailings dam failure in Brumadinho, have focused the world’s attention squarely on the often-challenging subject of tailings storage. Unwanted ultrafines, that are deemed to be unworthy of further treatment or not to have further saleable value, are therefore a significant issue for mine owners looking to reduce risks and perceptions associated with long-term storage of tailings. In this context, there are strong drivers to identify safer approaches to ultrafine tailings management, especially if it can also lead to increased revenue, together with better water stewardship and environmental outcomes. The better management of tailings needs to be considered from both containment challenge and processing opportunity perspectives. This paper focuses on the latter, reviewing from a technical and economic perspective, the feasibility of more extensive processing and/or reprocessing of specifically iron ore tailings, in a bid to reduce the overall volume for management in long-term storage. Herein the opportunity lies in recovery processing, as much as enhanced thickening and/or mechanical dewatering, and therefore the paper discusses both issues as equally important sides of the same coin. Recent interest in iron ore ultrafines processing and reprocessing studies suggests that the enhanced processing of iron ore tailings offers multiple perceived advantages. Apart from a potential reduction in tailings volume, associated with safer containment, lower environmental impact and improved water management, the prospect of increased revenue from additional Fe recovery presents supplementary motivation for iron ore players to embrace this approach, as further elaborated in this paper.

Nov 8, 2021

By Goode RA

It is-assumed that a pipeline system is economically justified as a means of transportation.. The terms "True Life" and "Economic Design Life" are defined. The most usual design alternatives to be considered from both physical and economic -viewpoints are listed and a summary is given of the main factors to be costed in assessing the relative economics of each alternative. A brief statement of the recor mended method af economic. assessment is given and an example is included. The paper aims to present a reasonably accurate, simple and practical method of considering the main economic factors which govern design.

Jan 1, 1962

By G Forbes, D J. Bradshaw, G S. Heinrich, D

Traditionally, operators on mineral flotation plants have relied on visual inspection of the froth surface when making adjustments to process set-points. Machine vision systems are being developed to relate froth surface descriptors, which can be consistently measured in real time, to flotation performance. By investigating the impact of various selected operating variables on both froth surface characteristics and metallurgical performance it is possible to develop a management strategy for the control and optimisation of the process. This paper presents the results of testwork conducted at Kennecott copper mine which investigates the relationship between the froth colour and the concentrate grade and discusses the factors which affect the froth colour. This work shows that the main factors that influence the froth colour in this system are molybdenum, copper and iron concentrate grade, pulp and concentrate per cent solids and pulp iron grade.It goes on to develop models to predict the concentrate grade based on colour information and velocity and stability information. It also shows that the most accurate prediction is made with combined colour and stability information.

Jan 1, 2005

Forty years ago Dr Pierre M Gy, a metallurgist, introduced variography as applied to monitoring a process. Consequently, his followers used the variogram to elaborate meaningful process control charts, especially since 1993. The name æChronostatisticsÆ was suggested several times by Gy as a logical name for this new science. The intent was to draw a parallel between the variogram identifying the variability components affecting a process parameter as a function of time, and the variogram used in geostatistics identifying the variability components of a given mineral content as a function of space. Heterogeneity problems encountered have indeed strong similarities. However, there is a fundamental difference. The variogram used in geostatistics is often stationary within a given type of mineralisation. While investigating a dynamic process through Chronostatistics, there is no such thing as a stationary variogram. Still, the evolving variogram provides essential information about subtle, often overlooked process difficulties. Chronostatistics is especially useful for management to take advantage of existing data that are often a forgotten source of valuable information to pinpoint recurring structural problems. The superiority of Chronostatistics over conventional statistical process control approaches is that it links observations to the inherent heterogeneity of materials under investigation, therefore to the sampling theory. Chronostatistics is like opening a new world to the metallurgist, making the process variability speak in a more comprehensive and in-depth way. Several case studies are presented to demonstrate the potency of this new science. For each of them, observations lead to solutions for continuous process improvement, therefore attractive economic opportunities. The philosophy is this: if a control chart shows a process is out of control, it must also suggest logical and pragmatic directions for solutions. The intent of this presentation is to vastly expand on these valuable, almost forgotten ideas.

Jan 1, 2006

Almost all the countries of the south-west Pacific and the Australian states have recently completed or have commissioned mineral royalty reviews. The prime reasons for this widespread and consistent action is the desire of the governments of these entities to redress perceived effi- ciency and equity imbalances and to ensure that the revenue raising motive does not override the necessity to maintain mineral exploration and development incentives. Governments are tending to adopt royalty systems comprising a com- bination of base royalty and a profit component. Resource rent royalty and royalty holidays have been introduced and anomalies, such as royalty free gold production, still exist but appear to have uncertain futures. Tasmania ranks as the Australian state with the lowest aggregate royalty levy/production value ratio whilst Papua New Guinea has the highest royalty objective achievement level in the south-west Pacific region.

Jan 1, 1988

By E Villaescusa, C Drover, I Onederra

Development face destress blasting is a construction technique in deep mining, which aims to prevent, reduce the frequency, or manipulate the timing of violent, stress-driven rock mass instability at the face. This paper presents a destress blasting design concept that was optimised for the specific rock mass conditions of a deep mine using the Hybrid Stress Blasting Model (HSBM) software. The design was then implemented in an area of the mine where stress-driven instability of the face regularly occurred during development. An adjacent tunnel was constructed in parallel without destressing, within the same rock mass conditions, as a control. The rock mass response to each excavation was quantitatively compared using high-resolution local seismic monitoring. Visual observations of the fractures created by destress blasting were also made. The analysis indicated that destressing reduced both seismicity and the rock mass stiffness ahead of the face. This was inferred from the spatial broadening of the development seismogenic zone and the typically significant reduction in the spatial density of seismic events. Seismic source mechanism analysis also indicated that destress blasting generated a much wider variety of failure modes than conventional blasting. Most seismic source mechanisms following destressing were associated with natural joint structures. A relatively small portion were consistent with newly created blast-induced fractures. The greater diversity of rock mass failure modes associated with destressing implied a lower potential for stain-energy accumulation within the rock mass at the face, and thus a lower risk of hazardous instability. Observations of visible rock fracturing indicated that the major principal stress influenced the damage intensity on natural geological structures within the destressed zone, and that numerical predictions of radial fracturing limits made by HSBM analysis were realistic representations of the real blasting performance.

Nov 29, 2022

As a society, the retiring age of workers is increasing. Individuals are having to consider working to an older age (beyond 55 years), the reason being to æpay offÆ debt, maintain a quality of life or, as a bigger picture, because society simply cannot afford the aging population. The Government is encouraging and promoting those approaching retirement to work to an older age to alleviate the financial burden of an aging population. In a working context those aged 55 years and over accounted for ten per cent of the Australian workforce in 1998 with this age group expected to account for half of the growth in the workforce between now and 2016. For the 60 - 64 years which account for less than three per cent in 1998, this group is expected to account for 15 per cent of the growth in the same period. As a result of individuals who have worked all their lives and in some cases æphysically hardÆ, they do not fully enjoy their years of retirement as a time when they get to choose what they want to do rather than what they have to do. Of particular interest are the physical or health related conditions that individuals end up with and the restrictions that ensue resulting in an individual being incapacitated either physically or with respect to the state of their health.

Jan 1, 2005

By J Harris, M Shi, S Vink, P A. Kirsch

Across the life-of-mine, water is both an essential commodity to mining, and one of the most significant hazards. In Australia, a land of drought and floods, availability of water is a critical strategic risk for mine sites and neighbouring stakeholders, with both insufficient water leading to curtailed operations and contested space, and extreme water closing operations through flooding of mine sites, transportation infrastructure and unplanned regulatory restrictions. In addition to these major strategic risks, water must be addressed in operational risk management activities in many different ways.This paper develops a set of categories for classification of water risks based on academic papers from the water in mining literature. These categories are applied to media content analysis of articles in International Longwall News (ILN) (an online coal industry news site) obtained with the search terms ‘water’, ‘rain’ and ‘flood’. Identified risks are discussed within the context of the life-of-mine. The paper uses these same categories to analyse the treatment of water risks in a new coal industry risk management body of knowledge called RISKGATE (http://www.riskgate.org, Minerals Industry Safety and Health Centre, The University of Queensland). The discussion of water risks in both INL and RISKGATE is compared and contrasted to pinpoint opportunities (and a roadmap) for further development of a specific RISKGATE water module for site-based operations. The media review also identifies areas for development of RISKGATE expansion topic(s) that would address other strategic water risks, eg severe weather events.CITATION:Shi, M, Kirsch, P A, Vink, S and Harris, J, ?2014. Water as risk in mining – media analysis and the RISKGATE body of knowledge, in Proceedings Life-of-Mine 2014 , pp 205–218 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By J Jackson, E Sellers

Blasting related indices were developed to quantify variation in rock strength and structure for each stope, and for each lift of each stope, as part of a Mine to Mill study at an underground open stope mine. The indices were derived from combinations of data from underground diamond drilling because the simplifying assumptions contained in the block model prevented sufficient differentiation in rock mass characteristics to enable adjustments to the blast design.Application of combinations of blasting related indices enabled the identification of stopes with a high potential for inconsistent and oversize fragmentation, underbreak and overbreak. The indices also fragmentation outcomes to deliver increased material flow within stopes, better digability and predict indicative mill throughput. The stopes with issuesCalibration of the results enabled adjustments to the blast design based on the rock mass conditions and accordingly improved the blast outcomes. This enabled improved productivity by reducing underbreak and overbreak, having a more appropriate fragmentation, which reduces unplanned rock handling and improves bogging. The reduction in recovery drilling creates huge opportunities to improve output by reducing production delays and decreasing the overall cost per tonne. By understanding the explosive performance and blast energy distribution in relation to rock mass blastability poor, performing designs in blind upholes and convex stopes were identified.The conclusion of the work is that value improvement, regarding increased revenue and reduced costs, can be achieved across the whole underground Mine to Mill process chain by developing stope based indices from the existing geological information to correctly tailor the blast design to the rock within, and surrounding, the stope.CITATION:Jackson, J and Sellers, E, 2017. Blasting related indices as the key to underground blasting improvements in a challenging rock mass, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 23–32 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017

By S A. McManus

With the advances in software speed and capability, many of us now are running multiple scenarios on entire models rather than just testing small areas or a few blocks. In the authors experience both the geological and geostatistical academic theory and our rules of thumb, often prove un-useable or incorrect in the real world we work in. The only way to truly validate and tune our models is to complete the entire model and ‘see if it works’. If it lacks some property we were expecting, then we need to find out why and/or run different scenarios to see what changes. This is not always possible with tight project timelines but we find ourselves doing more and more of this sort of thing, and in so doing, understand that every deposit is different and requires its own ‘rules’ to get valid and useful results. For the purposes of this paper, this process is termed Empirical Geostatistics. Take Clayton Deutsch’s ‘all realisations all of the time’ concept a step back. Before you even think of simulating, test the alternate realisations generated by alternate parameters such as different domaining, varying search neighbourhood parameters etc.

Mar 22, 2022

By J Nantel

Planning of modern mines entails considerable challenges in the areas of ground control, materials handling, safety, environment, equipment and personnel. Many orebodies are not economical unless efficient mining systems are used to win the ore. Relentless pressures are placed on mine operators to force them to become more productive and to make mines more competitive in modern economies. This has generated an intense drive to adopt technologies that rely on a greater degree of mechanisation, automation and computerisation. There is no turning back; high technology in mines is here to stay: computer controls and monitoring, computer aided mine design, information management systems, etc. During the past 20 years significant advances have been made in the areas of mine design, mine equipment and geomechanics. One could rhetorically ask if the advances in mine backfill technologies have kept pace with developments in other sectors of the mining industry. This paper will look at a few key mining technology sectors and will compare the relative progress of backfill technology to these sectors.

Jan 1, 1998

The Central Andes in Peru, Chile, Bolivia, and Argentina, contain two contiguous terranes which were accreted i, Gondwanaland between the end of the Devonian and the end of the Triassic. These terranes, Arequipa in the north, anni Chilenia in the south, differ from each other in the timing and style of their metallogenic development. However, they contain over 90% of the Central Andean porphyry copper resource. The copper porphyries in the Arequipa terrane are Paleocene to lower Oligocene in age, whereas the Chilenia deposits are mid-upper Cretaceous and mid-upper Miocene. Porphyry copper deposits occur outside these terranes, but are all Miocene in age. Miocene porphyry-style mineralisation also exists in the Arequipa terrane, but is copper-deficient and gold-rich. The accreted terranes may have favoured porphyry and other styles of copper mineralisation because they possessed relatively thin continental crust compared to adjacent parts of the Andes. Crustal thickening which commenced at about 30 Ma in the Arequipa terrane coincided with a major change to polymetallic, precious metal mineralisation which commonly displays high sulfidation charcteristics.

Jan 1, 1995

A variety of rockbolt designs and resin anchors are currently in use in underground mines. This paper identifies possible risk factors that may affect the intended performance of rockbolts. The paper also presents the outcome of a study on the variability of some aspects of fully encapsulated rockbolts undertaken across seven coal mines within the context of previous research findings on rockbolt anchorage performance.

Jan 1, 2003

By T Ireland, B Wright, S Weaver

All tunnels have unique characteristics that result in different fire and life safety risk. The fire safety systems for each tunnel also give different benefits at different costs. It is therefore neither pragmatic nor cost-effective to prescribe specific fire standards requirements for all tunnels. Each tunnel needs to be assessed individually but using a common process.The owner/client is normally the risk owner and needs to make the decision on what fire and life safety provisions will be provided within the tunnel. To make this decision they need to be appropriately informed. The low probability and high consequence nature of fire events creates a challenge such that traditional analysis processes, which tend to focus on a major event after it has happened, are not easily applied and do not give the best value for money. Therefore a process is required that provides the relevant information to the owner for decision-making.A quantitative risk assessment (QRA) provides a process and framework for the consideration of fire life safety risk when applied properly. This involves a risk assessment of the ‘do nothing’ option together with assessments of improvement options and their costs. It also involves consideration of benchmark safety levels for other tunnels and the open road.This paper will outline a QRA process for assessing fire and life safety risk in tunnels and how this has been used for three existing tunnels, Homer Tunnel, Lyttelton Tunnel and Mt Victoria Tunnel. Key challenges include determining an acceptable safety level, defining realistic inputs, providing sufficient complexity to get meaningful results but not so complex that transparency is lost and interpretation to enable decision-making by non-technical personnel.CITATION:Weaver, S, Wright, B and Ireland, T, 2014. A transparent and pragmatic quantitative risk assessment process for assessing fire safety in New Zealand tunnels, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 121–128 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

This paper explores options worthy of consideration in the management of S02 produced from the gold roasting operations at Kalgoorlie. Some of the options have relevance to other sources of SO2 in the region, eminating from nickel smelting operations. The paper considers the following options: 1. Capture of SO2 within the roaster where sulphur-containing reaction products are mixed with the calcine. 2. Processes in which the sulphur-containing products are bled separately from the stack for further treatment or for dumping as a waste. These include: Seawater-based scrubbing of SO2; Sulphuric acid manufacture as a feedstock for fertiliser production or for leaching of bauxite; its use as Caro's acid: and the production of value-added sulphur-containing reagents eg liquid S02 and sulphonic acid.

Jan 1, 1992

By G Brooks

The control of phosphorus in steelmaking is one of the famous challenges of pyrometallurgy. It is well established that highly basic slags, the presence of FeO in the slag and lower temperatures (less than 1650°C) are favourable for phosphorous removal. The thermodynamics of this reaction have been extensively studied under laboratory conditions and the general trends confirmed through industrial trials. However, in general, phosphorus slag/metal distributions measured in industry are far from equilibrium and quite specific to the oxygen steelmaking technology being used. This variability was quantified by Urban, Weinberg and Cappel (2015), who found that the phosphorus partition ratio measured in plants varied with blowing practice, stirring intensity and even converter life. Some recent kinetic studies by Gu, Dogan and Coley (2017) have shown how the kinetics of these reactions vary with FeO content and dissolved sulfur at the droplet scale. A global kinetic model by Rout et al (2018) provides meaningful predictions of where dephosphorisation occurs in an industrial basic oxygen furnace (BOF) and some recent heat transfer modelling by Madhavan et al (2021, 2022) implies that temperature difference between droplets and slag has a role to play in explaining why equilibrium is not achieved. This paper will review the current state of knowledge and provide suggestions on predicting phosphorous removal for industrial operations and how greater removal could be achieved.

Jun 19, 2024

By A Flatten, F Reusch

Recent advances in the disciplines involved in simulating large mining operations provide increasingly precise and accurate methods for the study of cave mechanics; however, in large regional-scale models, hydrological aspects are often neglected or studied independently from the mechanical problem. There exists a great demand for a unified approach to study and simulate both the mechanical and hydrological phenomena that allows for a more detailed understanding of the effects of groundwater flow, dewatering and the impact on block cave mining operations.This paper presents a numerical framework that combines three-dimensional regional-scale hydrological simulation techniques for groundwater flow, together with non-linear continuum–discontinuum rock mechanics models, provides such a unified modelling approach. The underlying simulation technique is based on a coupled parallel solution formulation adopting single-phase fluid flow formulations into a discontinuous, strain softening and dilatant finite element model. This approach is adopted for the presented case study of a realistic block caving example in a simplified unidirectional coupling formulation, to investigate the effects of the mechanical analysis on the hydrological response. Here, particular emphasis is on the non-linear coupling of the deformable and strain-softening solid skeleton and fluid phase; eg the change of hydraulic properties with evolution of damage in the rock mass and large-to-intermediate scale structures due to ongoing caving operations. The importance of discontinuum structures is discussed, as mining-induced fault reactivation significantly influences the hydrological response.CITATION:Flatten, A, Reusch, F and Beck, D, 2016. The application of hydromechanical mine-scale modelling for large block caving operations, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 341–348 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By M S. Powell

In this paper it is argued that we are entering a new mining era, based on considerably more challenging orebodies as we rapidly expand minerals production by exploiting previously uneconomic deposits. Rapidly increasing production costs cannot be sustained by continually increasing commodity prices, as illustrated by the recent downturn in the industry.Driven by reduction in grade, requiring the processing of 50 to 100 per cent more ore to recover the same amount of metal, often accompanied by finer grain structure - necessitating a finer product size and more challenging recovery - the productivity of the mining industry is dropping in real terms. The author suggests that tweaking current technologies and relying on economies of scale will not turn the industry around, but rather a switch to considerably more efficient processing is required.It is imperative to utilise the properties of the orebody, especially in terms of variability, in revolutionising our processing techniques. Our new mantra may be æselective mass mining with flexible processingÆ. This paper explores how this may be implemented using current technology and equipment in order to change the cost profile of the new mining industry. Orebody knowledge, based on the underlying process drivers, rather than proxies, is required. These properties and their variability will need to be propagated into the orebody through utilising the geological data rather than smoothing block averages, which destroys information on variability.Novel flexible circuit designs are presented that can respond to a wide variability in ore properties and throughput requirements in order to slash processing costs and energy utilisation, while enhancing overall recovery. The success of these circuits will be based on an ability to predict at both design stage and in everyday processing the variable ore properties, which is dependent upon reliable orebody knowledge that caries variability and underlying processing properties.CITATION:Powell, M S, 2013. Utilising orebody knowledge to improve comminution circuit design and energy utilisation, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 27-36 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

By A Calderon, J Harris, M Shi, D Viswanathan, C Ribeiro Duthie, P A. Kirsch

Mineral resource development activities impact the health and well-being of many people, from workers, to families and surrounding communities. In the current environment of corporate social responsibility life-of-mine planning considers that mining activities should be conducted in the best environmentally, socially and economically acceptable way for the entire life of the mine (ie from exploration to decommissioning and closure). In this context, the health impacts of mining extend throughout the life of the community from worker injury and chronic exposure to communicable and non-communicable causes of illness, through to family and community health and well-being. At the inaugural Life-of-Mine conference in July 2012, the authors proposed the life-of-mine in the life-of-community (LOMLOC) matrix as a framework for understanding issues at the interface between resource extraction operations and the surrounding environment.This paper reviews and compares health activities extracted from social and environmental reports published by selected major mining companies with American operations in Canada, Colombia and Brazil. These corporate approaches to public health management are mapped to the LOMLOC matrix to identify and compare trends and behaviour in corporate health investments. This analysis of how companies approach and prioritise health issues in the context of different regions, cultures and environmental drivers will serve as a resource for minerals industry managers, civil society and regulators regarding current health management approaches in this sector.CITATION:Ribeiro Duthie, C, Calderon, A, Viswanathan, D, ?Shi, M, Harris, J and Kirsch, P A, ?2014. Resource company investments in health – a life-of-mine / life-of-community perspective across America, in Proceedings Life-of-Mine 2014 , pp 349–364 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014