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By M Qiao, A Sugden, W Zong, J Hines, J Roberts, T Ren

Long-term exposure to respirable dust continues to present an occupational health and safety hazard to mine workers in underground mines. Workers who are exposed to mine dust can develop occupational lung diseases including coal workers’ pneumoconiosis (CWP) or ‘black lung’, progressive massive fibrosis (PMF) and chronic obstructive pulmonary disease (COPD). To demonstrate the exposure impact of certain working conditions and improve dust management in longwall development panels, this paper details the development of a computational fluid dynamicsvirtual reality (CFD-VR) based training tool. The tool has been developed as an educational platform to facilitate the effective communication of workplace health and safety (WH&S) dust control measures for continuous miner operators and engineers. The study introduces a promising approach to model ventilation and dust flow patterns based on site-specific data, employing computational fluid dynamics (CFD) for a detailed analysis and visualisation of these mechanisms. Additionally, an algorithm has been developed for processing the large and complex CFD data sets into a form amenable for visualisation within a virtual reality (VR) environment using standalone VR headsets with limited processing power. This training tool has been deployed to mine sites with the specific purpose of educating users on the hazards of dust emissions and the best practices for control.

Apr 16, 2024

By D Hunter

A production information management system (PIMS) was recently implemented at Queensland NickelÆs Yabulu Refinery. Although a strong business case was developed to justify the significant investment in PIMS some potential beneficiaries remained sceptical of the anticipated benefits. The decision to install PIMS was justified as the on-line availability of continuous production data enabled the optimisation of some crucial operations resulting in significant cost savings, improved throughput and final product quality. Furthermore the rapid access to extended historical data has allowed the cause of repeated failure of equipment to be determined. The investment is expected to pay for itself within two years and has already contributed towards significant savings. This paper focuses on some of the diverse production improvements gained and compares the anticipated benefits in the business case to those achieved. A brief outline of the phased implementation of the OSIsoft PI data historian and complementary client software at Yabulu is included, along with details of the lessons learned.

Jan 1, 2003

By M I. Pownceby, S Hapugoda, H Han, E Donskoi, L Lu

Iron ore sinter mineralogy and its associated macro-/micro – structure has a strong impact on sinter quality. At a macroscopic scale, sinter ideally consists of a strong, porous matrix which bonds relict ore nuclei together. Microscopically, the sinter matrix (solidified from the melt part of the initial sinter mix) generally consists of complex calcium ferrites known as SFCA, secondary magnetite and hematite grains (precipitated from the primary sinter melt), glass and silicates. Depending on the conditions under which the sinter structure is formed, two major forms of SFCA with different morphologies are generally recognised, ie fine micro-platy SFCA (usually termed SFCA-I) and coarse columnar/prismatic SFCA. Detailed optical microscope observations of several pot grate and compact sinter samples revealed the presence of a variety of fine, coarse and dense forms of both types of SFCA. The controlled cooling tests revealed that cooling rate has an impact on the form and size of SFCA crystals. In this work, EPMA analysis of SFCA compositions from a variety of pot grate and compact sinter samples are presented. Results show that the SFCA types exhibit a broad range of complex compositions within the system Fe2O3/CaO/SiO2/Al2O3/MgO/TiO2/MnO2. Although SFCA-I and SFCA are known to be crystallographically distinct and with different, well-defined ranges in composition, there was considerable overlap in compositions of the experimental sinter samples. The development of SFCA textures depend on several parameters including the local chemistry and conditions including the maximum temperature attained and the cooling rate, within the sinter bed, thereby suggesting that SFCA identification based on morphology alone may be erroneous.

Nov 8, 2021

By P Wilson

The Mt. Wright Underground Mine is located near the town of Ravenswood in North Queensland and is operated by Carpentaria Gold – a wholly owned subsidiary of Resolute Mining Limited. The establishment of the world’s first Sub Level Shrinkage (SLS) mine from a tradition Sub Level Open Stoping operation has proven to be a geotechnical challenge which has required tailored solutions to overcome unique issues. This paper will be broken into two distinct sections that will outline: a brief overview of the mining method and how the SLS method was chosen; and how the SLS is managed and key geotechnical learnings. The story of the world’s first SLS originated from the need of a bulk mining method to ensure the viability of Mt. Wright into the future. Traditional bulk mining methods such as; Block or Sublevel Caving were originally ruled out due to the low natural ‘cavability’ of the orebody and the proximity of the orebody to existing major infrastructure (Decline, Ventilation Rises and Egresses). The first section of the paper will outline the key geotechnical information that helped decide the SLS method in addition to how continuous backfill influenced the design. The second section is intended to address issues that the geotechnical engineers encountered since the inception of the SLS. The feature topic of this section is mining induced stress. Like most bulk mining methods, Mt. Wright had success when the production front was running parallel to the stress (production front being ‘shadowed’ from the stress). This was until a design change, forced by a splitting ore body resulted in this shadowing effect becoming harder to achieve. As a result, rehabilitation and production hole re-drilling become a regular occurrence, which teamed with a strict set of access controls made the production cycle longer and harder to complete. CITATION:Wilson, P, 2018. Mt Wright – geotechnical learnings from a sub level shrink, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 119–132 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By C Armstrong, B Wentzinger

Upstream embankment raises often represent the lowest cost option for increasing the capacity of tailings storage facilities (TSF), but also pose the highest stability risk due to constructing on top of previously deposited tailings.This paper presents an overview of key aspects in the geotechnical investigation and design of upstream raises and some recent lessons learnt from experience across a number of TSFs in Australia. A summary of recommended field investigation and laboratory testing methods is provided with a focus on collecting quality information for design purposes. A strong focus is given in developing an accurate assessment of pore water pressures, which, if not correctly understood can have disastrous consequences on tailings strength parameter interpretation and wall stability assessment in static and post-seismic conditions.The assessment of the contractive or dilative shearing behaviour of the tailings material and rigorous interpretation of design characteristic values are presented. Some comments on stability analysis options and proposed methodology are also provided.CITATION:Wentzinger, B and Armstrong, C, 2018. Lessons learnt in geotechnical investigation and stability analysis for upstream tailings storage facility raise design, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 333–348 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

Rather like the mythical "Economic Man" "an employer" in this context must necessarily be an abstraction, and the views possessed by such an abstraction, a composite of many views known to have been expressed. Not even the complex Conciliation and Arbitration legislation in this country provides any helpful specifications, except in one peculiar particular. The Australian Conciliation and Arbitration Act provides an almost totally tautological definition, except in that one oddity referred to above. It is this : "An employer means any employer in any industry, and includes any person who is usually an employer in an industry, and also includes a Club." No doubt there is some perfectly justifiable reason for such specific and unique particularity in an otherwise meaning- less definition. That need not trouble us in this exercise.

Jan 1, 1982

By A Kite

Frontline leaders play a critical role in the safe and productive operations of Australia’s mining, resources and heavy industries. These leaders set the workplace culture, especially during night shifts and weekends, by providing team direction and encouragement, providing access to resources, fulfilling statutory requirements, enacting and reinforcing risk management systems, setting the standards on shift and acting as the primary conduit of communications between senior leaders and team members.

May 5, 2022

In the general planning of this area, provision was made for the distribution over the whole area as required of the following services:(a) Power and lighting from the substation distribution boards 'located in the winder house.(b) Miscellaneous electrical indicating, control and signalling systems.(c) Telephone lines from the main internal automatic exchange located in the changehouse, the town exchange to the automatic exchange and also direct lines from the town exchange to selected offices.(d) Compressed air from the incoming 16-in. air main. (e) Water, both unfiltered and filtered; and the disposal of the following effluents:(f) Sewage from the area to the town sewage system.(g) Changehouse shower water to the regeneration area.(h) Storm water to the general mine surface drainage system leading out to the naturally drained area north of the No. 8 Shaft.

Jan 1, 1957

The major heavy industrial consumers of limestone are the cement, lime'and steel ind- ustries. Each of these requires large quantities of cheap raw material. Other ind- ustries such as glass and chemical manufactur- ing are significant consumers and agricultur- al and constructional activities provide additional demand which is usually more local in its occurrence. Limestone is widely dis- tributed throughout Australia but location in relation to major markets, and transport con- siderations render most deposits of no economic value. Among deposits which are sufficiently close to the major metropolitan markets many must be rejected as being unsuitable on grounds of quality, inadequate size for major.develop- ment, or other reasons such as environmental considerations. The major producing locations are sit- uated in a variety of geological environments. Most have limited reserves and require partic- ular attention to quality control. Planned extraction programmes based on detailed geo- logical investigations enable not only satis- factory grade control but also permit, by the adoption of appropriate quarry procedures, the use of sub-grade material, thus optimis- ing utilisation of the available reserves.

Jan 1, 1976

By P Corbett, P Sheffield

Centennial Coal operates the Springvale longwall mining operation which extracts coal beneath the Newnes Plateau in the Western Coalfields of New South Wales. Springvale, and the neighbouring Angus Place mine, have a history of difficult geotechnical conditions where combinations of a relatively high stress regime and weak, laminated roof and extensive geological faulting has led to numerous roof failures throughout the mine’s life. Following development, the mines underground roadways can experience high levels of roof movement which may lead to roof falls. Multipoint wire extensometers are extensively used throughout the mine for roadway condition monitoring, and to reactively drive remedial strata support through trigger action response plans (TARPs).As a result of the use of high-density extensometer monitoring over a long period, the mines have an extensive archive of legacy data. Data processing has evolved over time in order to accommodate the increasing data volume, including direct data entry from the recently introduced hard-wired real-time monitoring instruments. It is likely that telemetric real-time instruments will be introduced in the future, which will cause another step change in data management requirements. This paper discusses the transition to and evolution of relational database management systems for extensometer and associated data.This paper also presents case studies of the use of a new software tool for reprocessing legacy data to enable time-scaled visualisation of monitoring data in the context of longwall and development face positions and installed strata support. The software can be used proactively in the identification of geotechnical risk factors and their interaction with the mining process to allow a more robust geotechnical hazard process. It interfaces directly with the widely used ExtoChart database software and can be presented with scale drawings of geological and geotechnical data to allow correlation of monitoring data results with risk factors.CITATION:Corbett, P and Sheffield, P, 2015. The use of high-intensity monitoring data to better characterise geotechnical properties of a non-homogeneous rock mass, in Proceedings Third International Future Mining Conference, pp 145–158 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By D Connelly

The Iron Road Limited Central Eyre Iron Project (CEIP) area, located on the Eyre Peninsula of South Australia, covers extensive Archaean iron formations that occur as coarse-grained magnetite bearing gneiss. The cumulative strike length, estimated from aeromagnetic data, is at least 95 km.The project is located in a grain growing area 185 km west of the existing iron ore and steel making operations of OneSteel at Whyalla. A narrow gauge railway built to transport agricultural products to the deep-water port of Port Lincoln, 175 km to the south, traverses the project area. A number of well-serviced rural townships are located nearby. Current activities include resource expansion drilling, extensive metallurgical test work, community consultation and a Prefeasibility Study (PFS) that commenced in April 2010.The PFS has encompassed the Central Eyre Iron Project, comprising the three significant iron occurrences (Warramboo, Kopi and Hambidge) and was completed in early 2011. Extensive test work programs and metallurgical modelling confirmed viable process options for the project, using simple off the shelf processing technology.Preconcentration by coarse cobbing yielded promising results, and is the key to reducing not only the capital expenditure but also the operating cost, in particular the power cost, which is the highest operating cost component of a magnetite benefi ciation plant. The ore is also amendable to high pressure grinding rolls (HPGR) processing. This offers a potential for further reduction of the energy requirements.Test work also confirmed that a high grade blast furnace quality concentrate (~68 per cent Fe) can be produced at a relatively coarse grind (P80 106 µm).

Jul 11, 2011

By G York

South African gold reserves extend to great depths. However, strategies for the mining of such deposits have changed only slightly over the past number of years. Regional support at depth is currently provided by rock pillars and backfill. Many problems have been experienced with these regional support practices at deeper levels. In this paper several alternative forms of regional support are described which include the use of concrete, the use of back area caving and confinement to strengthen pillars. These new concepts are supported by numerical and laboratory modelling and in situ results.

Jan 1, 1998

By D Syme

In the middle of 2000, BHP Billiton implemented a Six Sigma Plus business improvement program known as Operating Excellence. It was developed based on a business bottom line initiative to deliver 35 - 40c/share and was one of the BHP Billiton strategies to deliver $2 earnings per share and a longer term $40 share price (BHP share price). Cannington is a silver, lead and zinc mine owned and operated by BHP Billiton. Through implementing Six Sigma Plus Cannington wanted to:have in-house capabilities to change and improve; tailor for the needs of each business unit and department; have æSharing of its KnowledgeÆ as a tool for improvement and have a competitive edge across Cannington û to be better than our competitors; learn from and leverage off the successes of improved safety and prior business improvement efforts; and ensure networking and sharing of information have common measurement systems across all assets. As with most business improvement programs û Six Sigma Plus was met with some degree of skepticism, especially given the amount of resources involved. After 18 months, much of this skepticism has been replaced with enthusiasm as peopleÆs understanding and acceptance of its fundamental concepts are being realised. The idea behind Six Sigma Plus is that it combines sound technical solutions with high acceptance by those who need to work with or implement the change. The future vision for Six Sigma Plus is that it become part of what we do at Cannington û just like safety and environment û so that Six Sigma tools and methodologies are used in our every day work.

Jan 1, 2002

By G Pasin, F Wirfiyata, G Khomaeni, W Valery, A Maclean, A Jankovic

The grinding circuit at PT Newmont Nusa Tenggara (PTNNT) – Batu Hijau mine consists of two SABC (semi-autogenous milling, ball milling, pebble crushing) trains, including four 20'?×?33'6? ball mills that have been lined with steel liners since the commissioning of the plant in 1999. During 2011 and 2012 an industrial trial was conducted to evaluate Poly-Met liners (a combination of rubber and steel liners). These new liners were installed in two of the ball mills (ball mills 1 and 2) and operated in parallel with ball mills 3 and 4 with steel liners.The objective of the trial was to compare the plant performance with the Poly-Met and steel ball?mill liners with regards to wear life, mill throughput, grind size and total unit costs. The trial was conducted over the entire life of the liners. The evaluation methodology implemented consisted of frequent spot sampling around the ball mill circuits, complete surveys/audits in both ball mills, and detailed analysis of process data. This paper presents the results of the industrial trial and main conclusions.CITATION:Maclean, A, Wirfiyata, F, Khomaeni, G, Jankovic, A, Pasin, G and Valery, W, 2014. Ball mill Poly-Met liner evaluation at PT Newmont Nusa Tenggara – Batu Hijau mine, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 255–262 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

Although laterite ores already provide a significant proportion of the world's nickel and cobalt production it is anticipated that they will surpass sulphide ores as a source of nickel in the next century. The most recent period of greenfield nickel project construction was during the 1970s when it was notable that all of the eight new plants were based on treating laterite ores. This was because of the relatively large selection of available high grade laterite ore deposits amenable to cheap open cast mining and a paucity of high grade sulphide ore prospect alternatives. Of the three processing options for treating laterite ores: 1. smelting for the lower horizon saprolite ore, 2. ammonia; and 3. acid leach for the upper horizon limonite ore, smelting currently accounts for about 80 per cent of nickel production. In the future, as saprolite ore grades decline because of relatively high exploitation rates, the incentive to process the large untapped reserves of limonite ore will increase. The high cobalt content of limonite ore also makes it ideally suited to processing by a hydrometallurgical rather than smelting route. With only two exceptions, all saprolite smelting operations have a Class 2 nickel end product (largely ferronickel) and do not produce a cobalt by-product. As a result of technological advances, the modified ammonia leach process for limonite and transition ore as undertaken at Yabulu, now allows the production of pure nickel metal as a Class 1 product, along with significant tonnages of cobalt by-product. The mixed Ni-Co sulphide intermediate product of the pressure acid leach processing of limonite ore at Mon is converted to Class 1 nickel and cobalt metal at Fort Saskatchewan, Canada.

Jan 1, 1996

By M Brady

"It has long been recognised that the barometer infl uences areas of underground coal mines that havebeen sealed off from the current, or active, mine workings but it appears litt le formal research hasbeen done on how the barometer aff ects the goafstream sample point. Based on statistical analysis of samples from a number of mines from Queensland and New South Wales it can be concluded that there is a direct correlation between the barometer and oxygen concentration at a goafstream sample point. To help mitigate some of the high consequence hazards within the underground coal industry and protect the health and safety of the persons within that environment, many monitoring tools are utilised. A control recognised in management plans prescribed under New South Wales and Queensland legislation is the need to conduct monitoring to identify the early warning signs of spontaneous combustion. One of the monitoring tools utilised involves a bagsample being collected from a goafstream sample point then returned to the surface for analysis.When the sample is incorrectly collected, the resultant analysis from a gas chromatograph provides litt le value to the persons charged with the obligation of operating the coal mine at an acceptable level of risk. This, therefore, increases the probability of spontaneous combustion leading to a loss of equipment, mine and in the worst case, life. When the sample is collected correctly, the analysis presents early warning signs of low level oxidation allowing corrective action to be taken, to prevent the oxidation accelerating to spontaneous combustion. The eff ect the barometer has on this sample point should be recognised and the knowledge imparted to persons who conduct sampling to remove a variable in the bag sample collection process. This will ensure the persons operating the mine have a bett er understanding of what is happening within their longwall goaf."

Jun 1, 2012

By A J. Gunson

The Norman B Keevil Institute of Mining Engineering, or the Department of Mining Engineering (the Department), at CanadaÆs University of British Columbia (UBC) is addressing the integration of sustainable development concepts into mining education and research on behalf of industry and society. Over the past decade, the DepartmentÆs education and research model has been evolving to incorporate collaborative and multidisciplinary strategies, where sustainability initiatives are taught in classes, supported in research and discussed in a voluntary collective of mostly graduate students û the Sustainability Working Group (SWG). The SWG has brought together a diverse array of disciplines from academia, industry, government, non-governmental organisations (NGOs) and mining communities. The operational mechanisms and structure of the SWG have enabled momentum to be gained through several multidisciplinary educational and research networking initiatives. It acts to attract new students with diverse backgrounds, foster innovative research, develop relationships and networks, and create the space to discuss progressive ideas and projects. The original cohort of SWG graduate students laid the foundation for sustainable research initiatives within the Department at UBC. Novel research has incorporated topics such as: community resilience, artisanal small-scale mining, sustainability indicators and corporate social responsibility, environmental assessment and impact benefit agreements and the recycling of waste. Propelled by the support of the Department and inspired by the works completed, a host of new graduate students have embarked on their research quests to integrate sustainability principles into their projects. Such projects include: social impacts and benefits of mining, artisanal small-scale mining, community health, the production and transport of mine pollutants, mine waste management, mineral process plant design and the evolution of community education and mine policy. This paper reports on the departmentÆs continuing research and development towards an understanding and evaluations of the ongoing contributions of mining to sustainable development.

Jan 1, 2009

By E S. Bernard

Toughness testing of fibre reinforced concrete (FRC) at 28 days age is typically undertaken as part of quality control for the many applications where fibres are used in concrete, including shotcrete, tunnel segments, and cast-in-place tunnel linings. The performance achieved at 28 days is usually assumed to be retained with increasing age. However, as the average strength grade of concrete used in most tunnelling applications, including tunnel segments, has steadily increased over the last 20 years, this assumption is becoming increasingly unviable. This is because for some types of fibre the mode of post-crack fibre behaviour depends on the strength of the concrete and can change from a desirable high-energy pull-out mode to a low-energy rupture mode as the strength and age of concrete increases. This paper describes a series of trials performed over two years in which the American Society for Testing and Materials (ASTM) C1609/C1609M beam tests were used to assess the performance of FRC reinforced with two widely used brands of steel and macro-synthetic fibre. The hooked-end steel fibres used for half the beams exhibited a dramatic fall in performance beyond 56 days age as the mode of failure changed from pull-out to rupture. The other fibre did not exhibit a fall in performance with age. This phenomenon highlights the need to quantify performance of FRC at much later ages when long-term performance is required, for example, to resist seismic events or changes in ground stress due to nearby excavations. As an alternative, a reduction factor may be applied to the performance of FRC mixes for which evidence of satisfactory long-term performance is not?available.CITATION:Bernard, E S, 2014. Age-dependent changes in post-cracking performance of fibre-reinforced concrete for tunnel?segments, in Proceedings 15th Australasian Tunnelling Conference 2014, pp 229–236 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By M Hawkes, Z Ji Gang, Z Ming, R Hassell

As underground mines become more geotechnically challenging with increasing depth and excavation size, the requirement for ground support to be installed as per design becomes more critical. The verification of installation quality for cable bolts and grouted rock bolts is difficult to assess. Current methods to control quality have limitations; pull testing is largely inconclusive with only extremely poor installation being identifiable. Audits during installation can only capture a small percentage of installed bolts. Following large rock mass displacement from either squeezing ground or seismic events, even previously well installed bolts may have yielded and require replacement. A method to provide an improved understanding of the reinforcement installation quality is Non- Destructive Testing (NDT) using acoustic reflection. To validate the accuracy of an NDT system, both plain and bulbed strand cable bolts were grouted in clear plastic tubes. The encapsulation grout quality was deliberately varied from full encapsulation through to partial encapsulation and a range of different size voids. The clear tubes allowed the ground encapsulation to be observed. Cable bolts strands were cut at varying lengths and different water cement grout ratios were used. Acoustic testing of the cable bolt specimens was completed blind; the technicians were not aware of what was being tested. The NDT results correlated well with the grout encapsulation, with differences between full encapsulation, minor voids and major voids being determined. The different water cement ratio and bolt lengths (including when partially cut) were also identifiable but with some discrepancies. Trials of the technology underground have also shown the data collection process to be relatively quick with each bolt taking 1-2 minutes to test, with interpretation of the results able to be completed soon after. The NDT results collected from the underground trial showed a wide variance in cable bolt grout encapsulation quality indicating that there were installation issues.

Mar 15, 2021

By P F. Knights, P Boniwell

This paper investigates the causes of low effective utilisation of the production drill fleet at the Telfer Underground Gold Mine, as measured by the percussion hours per shift. The first part of this paper focuses on a site time and motion study conducted to accurately identify shift time allocation and optimal drilling parameters (manual versus automatic, and suitable flushing mediums for varying ground conditions) as well as quantifying the business potential for automated or remotely operated production drilling. The second part of the paper focuses on the rate of successful hole completion for automated production drilling during shift changes. Two main areas of drill optimisation were identified. Firstly, a site-specific drilling procedure was established so as to ensure that all operators were drilling using optimal parameters. Total production metres per rig increased by 10.7 per cent as a result of the implementation of this standard. It was observed that a 25 per cent faster overall drill cycle was achieved using air mist flushing, and that manual drilling achieves a 19 per cent faster overall drilling cycle in comparison to automated drilling. Secondly, routine provision to the maintenance department of automation reliability reports that outlined the principal causes of unsuccessful hole completion led to an increase in production metres of a further 4.1 per cent, measured between January 2007 and August 2007. First hole automation reliability increased from 39 per cent to over 77 per cent over the same time period. Second hole automation completion was increased to 74 per cent, leading to a higher proportion of production achieved through automated technologies.

Jan 1, 2008