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Government established and financed the NZ Steel Investigating Co in 1960. Its investigations showed that a steel industry was feasible and desirable based uponNorth Island titanomagnetite ironsands, and charted a route for its establishment. The initial processing used post-1945 preheating and prereduction developments, but later innovative improvements created what was essentially a new New Zealand technology. Of the North Island titanomagnetite deposits: the small ones at Waipipi were best made available for export; those at Kawhia and Taharoa were too remote for the economic siting of a mill; that at Raglan proved too small; while at Waikato North Head three times the requirement of 50 million tons of concentrate were located in two sand areas averaging 18 per cent titanomagnetite. Economic studies showed that a South Auckland site would be ideal, close to New Zealand's biggest market. The mill site, on a basalt flow at Glenbrook, was located by a half-day's fieldwork - near both the Waikato North Head deposit, and a railhead for bringing in Waikato coal, etc, and taking out steel products.   This development was one of several since World War II which altered significantly the lives and homes of New Zealanders (others were natural gas, oil, geothermal power, epithermal gold, aluminium, opencastable lignite, etc). All had the essential ingredients of the highest government backing, direct or indirect government finance, and first-class New Zealand scientific and engineering skills (eg to create new technologies). Not one such project failed.

Jan 1, 1993

By D Kentwell

This extended abstract and associated presentation provide a series of real examples of the complex interactions between the numerous input parameters, both geological and mathematical, that are required for resource estimation. Many of these parameters can contain a large degree of uncertainty at the initial resource stage. The resource tonnages and grades at economic cut offs of some types of deposits are relatively robust to these initial uncertainties while others exhibit significant sensitivity. In some cases, changes in parameters can result in counter-intuitive outcomes. Grades and confidence levels are inseparable; as the parameters change the confidence changes and so does the grade estimate. The extended abstract and associated presentation also discuss the question of whether or not a single solution is still an acceptable outcome for an estimate or if even a set of simulations based on a single fixed set of parameters is acceptable.CITATION: Kentwell, D, 2018. Sensitive dependence on initial conditions in resource estimation, in Proceedings Complex Orebodies Conference 2018, pp 28–30 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

This paper examines the complex interplay of deposit characteristics, mining plans, tailings disposal techniques and rehabilitation requirements on planning for mineral sands operations. All component parts of this mining cycle are interdependent and cannot be evaluated in isolation when optimising a mineral sands operation. This is most evident when projects are large-scale or involve resources that contain complexities such as high slimes content, consolidated hard band materials, acid forming materials and radioactive materials. Projects located in environmentally sensitive areas add further to the need for more stringent planning. This paper describes the analysis techniques adopted by Hatch to evaluate mining and tailings placement options for a dredging and floating concentrator system. The principles and methods used in the analysis are applicable to any mining system involving the complexities listed above. The focus of this paper is on the reconstitution of mined material as tailings and the impact of this process on mining schedules and tailings construction and placement options.

Jan 1, 2001

By C Sylvestre

Leaders have invested heavily in traditional safety management to improve safety performance over the years. This primarily involved: • fixing the environment (eliminating the hazard) • improving the system (more/less rules, procedures etc) • making safety more conscious (more/better interactions about the importance of safety). These approaches have helped improve safety performance significantly during the last 50 years and will continue to play a role in the future. Although these approaches may be part of an overall solution, they are not enough to prevent many incidents. Today, these three approaches are used more than before, and are used better than ever before. Yet, workplace fatalities in Australia have stagnated from 2013 to 2019, as have the number of incidents, even serious ones. In the USA, workplace fatalities have increased by 15 per cent in the same period.

May 5, 2022

By B Murphy

Seeking to reduce the likelihood of uncontrolled personnel entry into the operating footprint of a dragline, Coronado Global Resources initiated a review of proximity detection systems currently available and equipment interactions in and around dragline operational areas. At the time of the assessment, there were no established personnel proximity detection systems in compliance with functional safety standards for large machinery in Australia. Our primary objective was to guarantee a functionally safe outcome, particularly by implementing a performance-level-rated system in accordance with AS4024 (Safety of Machinery series of Australian Standards). Applying appropriate detection technologies, the goal was to reduce the residual operating risk for machine-to-machine and machine-to-personnel interactions. A comprehensive analysis of available or in-development technologies was conducted, and a layered approach (demonstrated in Figure 1) was adopted to achieve the desired risk reduction by segregating the sensing zones into distinct areas using diverse and disparate technologies consisting of radar (short); light detection and ranging (LiDAR) (medium); and optical (long). To address the potential limitations of each technology, overlapping layered sensing zones were designed. With LIDAR and optical using two distinct artificial intelligence (AI) systems to classify detections, these were specifically trained to handle the unique environments of a mining operation.

Sep 1, 2024

By M Alston

Many organisations struggle to yield meaningful outcomes from incident investigations. This paper will demonstrate that we can discover systemic issues by rethinking the ‘Why’ and ‘How’ of investigations, fostering genuine risk reduction. Key points: 1. Shift from ‘prevent recurrence’ to ‘learn and reduce risk’: conventional investigations focus narrowly on recurrence prevention, resulting in narrowly focused investigations with limited ability to identify and reduce organisational risk. Redirecting our objective to learning and improvement opens avenues for broader risk mitigation. 2. Understanding daily work for risk insights: recognise that work is not always completed in full compliance with procedures. Workers will adapt how they complete tasks influenced by the conditions and management systems that exist every day. Understanding the conditions and systems affecting everyday work is vital for uncovering systemic risks. 3. Unearth systemic issues through in-depth exploration: many investigations address surface concerns such as lack of training, incorrect procedures, equipment not being maintained, and missing overarching organisational risks. Systemic, organisation-wide risks are not identified. To discover these systemic issues and create shared learnings, investigators must question management systems, including resourcing, planning and risk management. 4. Design actions for safe failure: common actions like discipline and training fall short and do not reduce risk. Resilience emerges from well-designed controls. Incorporate planning, better resources, interlocks, and guarding to bridge the gap between task execution and risk. 5. Investigation Reports as a Business Case: Investigation reports should not simply state historical information regarding an incident. They are to facilitate decision-making and be presented as a business case to drive change. Organisations can move beyond localised risk and ineffective administrative actions by changing investigation objectives and methods. They can facilitate learning, understand daily work intricacies, identify systemic issues, and enhance the capacity for safety, driving lasting risk reduction.

Apr 16, 2024

By A Satyanaga, H Rahardjo, K G. Mercer

The soil-water characteristic curve (SWCC) is one of the most essential soil properties in unsaturated soil mechanics. The water flow and storage characteristics of an unsaturated soil are closely related to the amount of water contained in the pores and the negative pore-water pressure in the soil. These are both in turn, related to the particle-size distribution and the plasticity of the soil. The SWCC is obtained by laboratory testing which is difficult to perform, costly and time consuming. There is a significant advantage in establishing typical SWCC envelopes for different soil types from a geotechnical design and analysis viewpoint. This paper presents some of the research work undertaken by UWA and NTU to develop SWCC envelopes for soil types classified in terms of the ASTM D2487 Unified Soil Classification System (USCS). This was done by establishing a large database of soils from across the world, classifying them according to ASTM D2487 and undertaking SWCC testing for each soil. This paper presents the SWCC test results from a selection of three of the most common soil classifications encountered in geotechnical engineering practise.CITATION:Mercer, K G, Rahardjo, H and Satyanaga, A, 2018. The development of soil water characteristic curves for soil types classified according to the USCS, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 263–273 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

Thank you for the opportunity to speak at this important conference attended by aspiring mining professionals, some of whom will become the leaders of the mineral resources industry that forms the solid foundation of AustraliaÆs past and that will fuel the exciting growth of AustraliaÆs future.I want to briefly touch on the history of our business, then look at the opportunities that exist in the contract mining industry and finally comment on what the educators need to consider in their curriculum to meet the needs of our business. Byrnecut started out as an idea in early-1987 developed by a group of four mining people. At the time the industry was on the high end of a mining boom, the era of the Bonds, Connels, Skases and so on. Riding on this wave of euphoria we borrowed $600 000 from the National Australia Bank and, without having enough knowledge to lose sleep over the potential risks, started business in mid-1987. The euphoria quickly evaporated with the 1987 October stock market crash. The bank pulled our overdraft, equipment finance rates increased to over 20 per cent per annum and my house was mortgagedseveral times over. The business learning curve was extreme for a young mining engineer who had developed his trade in the relatively sheltered environment of a large public mining house, namely WMC. We were somewhat bitter that the banks had done a runner. We were a private company, backing the business with personal assets with our shoulders to the wheel, whilst the Bonds of the world had theirnoses in the trough ripping off mum and dad shareholders. All of this had a sobering effect, namely keep your feet on the ground, stick to the knitting, work hard and worship cash flow. Since that stressful but adrenaline pumping beginning the company now employs over 600 people and is now working for major mining houses at over a dozen locations in Australia, east Africa and WesternEurope and the National bank is again our banker. On this basis I consider myself qualified for the subject of this speech.

Jan 1, 2002

By H Austrheim, A K. Engvik, A Putnis

How aqueous fluids move through rocks and minerals is a question of possible pathways and mechanisms. Existing pathways such as fractures and grain or mineral boundaries provide obvious channels for fluid movement. We show how minerals reactive in the presence of an interfacial fluid can be replaced by new product phases through a process of interface-coupled dissolution-reprecipitation. A resulting porosity in the new phase provides a new pathway for fluid movement and therefore mass transport through the mineral, which progressively reacts at a moving interface. Eventually fluids of new and changing composition can pass through originally solid minerals and move on further, taking remobilised elements with them, to be reprecipitated whenever the chemical and/or physical conditions allow. One such example is albitisation of rocks associated with mineralisation.

Jan 1, 2008

By M Zoorabadi

Overcoring is a common technique to measure in situ rock stress using the concept of stress relief. The strains measured during overcoring are used to calculate the stress tensor assuming continuous, homogeneous, isotropic and linear elastic behaviour. This approach does not recognise any effect of the thickness of the rock annulus produced during overcoring instead assuming that the stresses are entirely a function of the difference in strain between the start of the overcoring and the end with no regard to the transient strains produced. Three-dimensional numerical modelling was used to simulate the overcoring process and investigate the impact of core diameter on the transient stresses and strains during overcoring. This study showed that in thicker core, maximum transient axial stresses and strains occur when the drill bit approaches the measuring point and greater tensile axial stresses were produced when the annulus was thinner. CITATION:Zoorabadi, M, 2018. Numerical study of annulus thickness on overcoring stress measurements, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 274–278 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

Reconciliation involves the collection of tonnage, grade (quality) and contained metal (product) data from disparate and hopefully independent sources. Examples are exploration data, production sampling data from blastholes or drawpoints, and process plant data. These data may be compared by means of ratios (factors). The F1 factor usually relates short-term (ore control) model tonnages, grades and metal content to ore reserves depleted. The F2 factor usually relates received-at-mill tonnages, grades and metal content to delivered-to-mill = production tonnages, grade and metal content. The F3 factor is F1 × F2 and enables a comparison of a mineÆs ability to recover the tonnage, grade and metal content estimated in ore reserves. The F1 factor measures the accuracy of orebody knowledge in the ore reserves to the demarcation of ore and waste by ore control (short-term model). The F1 factor may be used to check and calibrate the selectivity of mineral resource models and/or planned dilution assumed in transfer from mineral resources to ore reserves. The F2 factor enables a check on unplanned dilution entering the ore stream between ore control and the mill. Using the factors it is possible to calculate a monetary value on improvements in the accuracy of orebody knowledge, selectivity and the effects of dilution and ore loss. Reconciliation should be an implicit part of the mining process, and reconciliation targets should be a key performance indicator for well-run mines.

Sep 26, 2011

By J Tien, J Huang, N Haque, M O’Brien

Coal preparation is an integral part of producing coal for thermal powerplants and metallurgical processing plants. Coal processing plants use various unit processes to separate gangue and ash content from mineral coal, thus increasing the specific energy content.A flow sheet and a simulation model was established for a typical coal processing plant using Microsoft Excel. This model used the mass balance and split factors for run-of-mine (ROM) coal, tailings and water usage from a typical, generic coalmine.The common method of coal preparation initially involves several stages of crushing to reduce the size of coal. It is then sent to the processing plant for further washing. The typical method in Australia for coarse coal material processing is the use of dense medium cyclone (DMC) (Kininmonth and Baafi, 2009). Flotation cells are used for processing of fine coal. The fine products are utilised for coking coal only. In our case study, the intended coal product is for thermal powerplants. Therefore, the fine coal processing utilised spirals instead of flotation, which is typical for the industry.CITATION:Huang, J, Haque, N, O'Brien, M, O'Brien G and Tien, J, 2016. Development, simulation, economic and environmental evaluation of a coal processing flow sheet, in Proceedings Life-of-Mine 2016 Conference , pp 48–51 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By D David

Geometallurgy is often a misunderstood and poorly defined concept. The first thing the paper will attempt is to provide a definition of geometallurgy. Ultimately this paper has been written to provide guidance to geologists, mining engineers and processing professionals as to what geometallurgy means in the crucial early phases of a potential mining project between the time of discovery and the time of commencing construction, should this occur. The paper covers the options available for conducting a geometallurgical study of a resource or orebody, appropriate to the level of definition required in the projectÆs development cycle. The paper will then describe how the geometallurgical information generated is subsequently used in calculations, planning and preparation of reports designed to inform and reassure stakeholders, such as the market. Ultimately in a successful project, appropriate options adopted in the development phase will form the basis of an ongoing geometallurgical program that links the major site disciplines for the good of the operation.CITATION:David, D, 2013. Geometallurgical guidelines for miners, geologists and process engineers - discovery to design, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 129-132 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

PIP is regularly engaged in businesses where Greenfield Capital Projects are under- delivering on the expected business case. In most of these projects, we can identify that rigorous review has been carried out on the design and financial cost elements and substantial reporting is maintained to Boards on progress versus plan of project completion and cost. However, in all sites of this nature that we have worked at, the planning, design and execution of the operational elements or æwiringÆ of the organisation have fallen short and resulted in significant extra cost or opportunity cost (lost tonnage or quality) during start-up. When compared to the amount of planning and resources that have been poured into the capital side, the ledger on the æwiringÆ side is typically fairly sparse. This presentation outlines the importance of running a disciplined, rigorous process to prepare the human and wiring side of a start-up to ensure rapid start-ups and put the site on the pathway to high performance. It gives an outline of the rigorous process PIP has used with projects to ensure excellent start-ups.

Jan 1, 2006

By Hannan JC

Consent to develop and operate a new coal mine in New South Wales (NSW) will be conditional upon a number of environmental controls. In NSW, applications for any new major development associated with coal mining are determined by the Minister for Planning and Environment. The environ- mental conditions placed on the development consent, the coal mining lease and the approvals, and licences under the pollution control legislation amount to a substantial component of any new project's commissioning considerations. The nature, scale and location of projects and the principles of pollution control on which conditions of State Pollution Control Commission (SPCC) approvals are based have a considerable influence on project planning. The design, construction and operation of coal mines in NSW has been progressively modified over the past 15 years, to incorporate increasingly stringent requirements for environmental management. These requirements are in turn, a reflection of a greater community demand for environmental protection.

Jan 1, 1986

By I Onederra

A better understanding of the detonation performance of an explosive charge can be gained by directly measuring pressure, temperature and velocity of detonation (VOD). This is particularly important with explosives used in the mining industry because their performance is directly influenced by the degree of confinement given by the borehole diameter and the surrounding rock mass. A project funded by the Australian Coal Association Research Program (ACARP) was initiated in early 2009 with the view to design and build cost-effective prototype instrumentation to measure the relative differences in detonation pressures and temperatures of commercial mining explosives. The project’s primary focus was on low-density explosives. Low-density (also referred to as low shock) explosives have been available in various forms for nearly 20 years. There have been significant advances in the availability, reliability and flexibility of these explosives, which now offer a range of densities and degrees of water resistance. Their detonation performance is not well understood and cannot be accurately predicted with current ideal and non-ideal detonation codes. It was therefore viewed as important to be able to directly measure pressure and temperature during the detonation process of these complex mixtures in production blastholes. Identifying the pressure release patterns of both conventional and low-density explosives under different geotechnical conditions should provide the necessary information to both validate detonation codes and better define input parameters for breakage and fragmentation models. This paper gives a general description of the prototype instrumentation developed and reports on the results obtained to date in full-scale conditions.

Nov 8, 2011

'Industrial Minerals - their mining and use in New Zealand' is the theme of the 1978 Annual Conference of the New Zealand Branch of The Australasian Institute of Mining and Metallurgy. This paper describes the use of phosphate rock, sulphur and potassium chloride (potash) - three industrial minerals which have enabled the farmers of New Zealand to increase production to current levels. The growth of imports of these raw materials for the New Zealand fertiliser industry is well documented in NZ Fertiliser Statistics 1977. This is the most recent of the Ministry of Agriculture and Fisheries annual publications on this Subject prepared from the detailed returns of fertiliser manufacture and sales from each fertiliser works. There are now 12 of these works in New Zealand one of the most recently established being in Whangarie where this conference is being held. Its capacity to manufacture superphosphate will shortly be 300 000 tonnes twice that when it opened late in 1964. New grinding and manufacturing equipment comes on stream early in 1979. This paper illustrates the interdependence of two primary industries, agriculture and mining. New Zealand's economy in the foreseeable future will be based on agriculture so that our standard of living is dependent on the overseas prices and freight costs of the bulk raw materials from which our fertilisers are made. For the year ended 31 March 1978 New Zealand's total exports were $3395 million, of this total $2413 million (71%) came from the products of pastoral agriculture (wheat, wool, dairy and other animal products), $291 million from forest products and $501 (15%) from manufactured exports. Approximately half of the pastoral receipts can be attributed to the fertilisers applied at a total cost of about $200 million including subsidy.

Jan 1, 1978

Batch centrifugal gravity concentrators have become standard equipment in gold grinding circuits for recovery of gravity recoverable gold (GRG). The downstream benefits of installing a gravity circuit are well understood, and in general, if there is a reasonable amount of GRG in the ore, a gravity circuit is usually installed. The benefits of gold gravity recovery have also been well documented, with a large database of successful case studies. As well, predicting production scale gravity recovery results ahead of installing gravity has become a common practice. The missing link between lab and full scale has always been the ability to predict the recovery benefit of installing gravity ahead of actually doing so. Being able to predict the recovery benefit in advance would help an operation in assessing the economic benefit and help justify the capital costs of the gravity circuit with much less uncertainty.

Aug 1, 2010

By M Olsson, I Bergqvist

A Swedish table of blast damage depths has, in one form or other, been in use since the late-1970s. Its history and the underlying theory are described. New experimental and theoretical findings that point out a number of shortcomings in the table and the underlying theory are presented and discussed. A revised version of the blast damage table was recently introduced in conjunction with new but incomplete recommendations for cautious perimeter blasting. The new table leaves the difficult task of taking into account factors like decoupling, water in the borehole, the rock properties, type of initiation, charge length and the actual bit diameter to the user. This paper discusses different ways of doing this, based on the experimental findings and a recent formula for the prediction of the lengths of radial cracks behind the half-casts. The material presented in this paper is meant to supplement and extend the new Swedish recommendations for cautious perimeter blasting of tunnels, shafts, pits and road cuts.

Jan 1, 2001

The theme at this yearÆs AusIMM New Leaders Conference in Ballarat was æThe Minerals Industry û Future Directions for New LeadersÆ. There was a strong focus on the recruitment and retention of trained and skilled graduates and new professionals into the mining profession. This paper highlights some of the key findings and discussion points from the New Leaders Conference. While some of the main causes of the decline in attracting new geoscientists to the mining industry have been identified, there still remains a lack of accountability among a number of Australian mining companies. Some of the factors identified that are driving new graduates away from the industry include; the social and geographical isolation, the long hours in challenging conditions and a difficulty in obtaining work straight out of University. Often there appears to be no clear opportunities within companies for career development and advancement. The opinion also still persists that the mining industry is lagging behind in both environmental and technical developments, which makes entry to the industry unattractive. Solutions that some of the large players in the Australian mining industry are implementing to help reverse the trend include targeted marketing of the lifestyle, money, freedom and travel offered in the mining industry, the development of graduate recruitment programmes and much more emphasis on the quality and reputation of the companies themselves. Incentives to attract families have also been significant in attracting and retaining employees whom otherwise would have left the workforce. However, more still needs to be done to completely reverse this trend and the mining industry needs to continue to be proactive in marketing itself as a desirable employer and career choice option for students and new professionals.

Jan 1, 2004