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By C Mark

Coal bursts involve the sudden, violent ejection of coal or rock into the mine workings. They are a particular hazard because they typically occur without warning. During the past two years, three US coal miners were killed in two coal bursts, following a six-year period during which there were zero burst fatalities.This paper puts the US experience in the context of worldwide research into coal bursts. It focuses on two major longwall mining coalfields that have struggled with bursts for decades. The Utah experience displays many of the ‘classic’ burst characteristics, including deep cover, strong roof and floor rock, and a direct association between bursts and mining activity. In Colorado, the longwalls of the North Fork Valley (NFV) also work at great depth, but their roof and floor strengths are moderate, and most bursts have occurred during entry development or in headgates, bleeders or other outbye locations. The NFV bursts also are more likely to be associated with geologic structures and large magnitude seismic events. The paper closes with a brief discussion of how US longwalls have managed the burst risk.CITATION:Mark, C, 2014. Coal bursts in the deep longwall mines of the United States, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 33–40 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By J L. Merritt

The mining industry seeks to engage with and respond to stakeholders through open consultation processes during the various phases of a mining project (Department of Industry, Tourism and Resources, 2006). Two Australian Coal Association Research Program (ACARP) funded projects conducted in the Bowen Basin coalfields in Central Queensland investigated the use of a stakeholder panel for the evaluation of mine site rehabilitation. The panel members were drawn from the local and regional area, and represented neighbouring landholders, traditional owners, AgForce, local government, conservation groups and non-governmental organisations (NGOs) such as Greening Australia and the Fitzroy Basin Association. The approach of utilising stakeholders to establish rehabilitation criteria was proposed as an alternative to the established practice of assessing rehabilitated areas against a suite of quantitative completion criteria; eg >70 per cent vegetative ground cover or <5 t/ha/a soil loss. The basis of this approach recognises the reality that the definition of completion criteria has proved problematic over the last 40 years with no broad consensus reached on the suite, let alone the metrics; eg the exact cover level that will benchmark acceptance of the mine site rehabilitation.CITATION:Merritt, J L, 2016. Zooming out – learning to see rehabilitation through stakeholders’ eyes, in Proceedings Life-of-Mine 2016 Conference, pp 163–165 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

Conceptually coal reserve assessment is simple but in practice it presents many problems. These arise from the origin and geological history of coal seams and from the diverse nature of the coal itself. The suitability of a coal for a particular use depends upon its type and so sheer quantity of reserves does not guarantee the adequacy of coal reserves for all requirements. Codes have been formulated to counteract the effects of subjectivity in reserve assessment. The code for calculating and reporting coal reserves published by the Standing Committee on Coalfield Geology of New South Wales has wide acceptance but the Committee itself recognises that it has shortcomings. Currently the Committee is engaged on the commendable but difficult endeavour of formulating a code that will meet the needs of scientific rigour and professional and commercial ethics and that will allow the specification of an assessment method without constraining it. It is generally agreed in the coal industry that the assessment of coal reserves can not conveniently be incorporated into codes formulated for other resources.

Jan 1, 1979

By Ballantyne GH

The Ladolam gold deposit on Lihir Island, in Papua New Guinea, is a large disseminated gold deposit hosted by hydrothermal breccias. The deposit occurs in the cupola zone of a 350,000 year old monzonite stock which is emplaced in the collapsed caldera of a shosho- nitic stratovolcano.

Jan 1, 1987

By M A. Noppé

"Mining is an inherently risky business: from the technical, environmental, social and economic uncertainties associated with advancing an exploration concept to a viable project; to the risks associated with the operating, market, and safety risks and uncertainties attached to a developed mine; and the final mine closure process.Investors and other stakeholders assessing the risk, opportunity and relative value associated with a resource project need to appreciate the project in its correct context. Errors, omissions, biased reporting or conflicting information in reporting may result in a misinterpretation of technical and financial results, leading to biased estimates or assumptions on project value (Noppé, 2016).Simplistically, a project can be assessed on three key areas for positioning the project in its correct relative context, namely: the project development stage the confidence in the estimated quantities and qualities of the resource, reserve and/or product the level of accuracy, precision and confidence in the technical and economic studies supporting the project.In the latter case, the ‘technical and economic’ information includes assessing the necessary social, environmental and commercial/legal/governmental approvals for the project.Responsible management of a resource project through its full life cycle relies on competent and dependable control and direction being effectively provided by the technical, business and board leadership of the organisation. In turn, the project information must be effectively communicated between various disciplines, these disciplines and the company, and the company and its stakeholders.CITATION:Noppé, M A, 2016. Responsible management and transparent reporting across the project life cycle, in Proceedings Life-of-Mine 2016 Conference, pp 5–7 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 28, 2016

By E Yurakov, D J. Ashelford, M I. Slate

The push for increasing coal production rates continues to place increasing demands on mine management to safely and effectively control seam gas. Gas drainage strategies applied vary in both effectiveness and form. Methods employed are a function of assessed risk, gas reservoir characteristics, surface and underground access, budgetary constraints and gas utilisation potential. With the aim of establishing and optimising the effectiveness and efficiency of gas drainage systems, Australian coal miners in cooperation with gas management specialists are embracing the use of gas reservoir simulators and gas emission models. This paper discusses the evolution of gas drainage practices in Australian underground coal mines and the role of gas reservoir assessment methods in optimising gas drainage systems and gas production forecasts.

Jan 1, 2005

The Sao Chico gold project is located on the Tocantinzinho trend which is the most mineralised zone in the Tapajos Mineral Field of Brazil (see Figure 1). The Tapajos goldfi eld was the site of the biggest gold rush in Brazilian history in the late 1970s and 1980s when approximately 500 000 garimpeiros (artisanal miners) rushed to the area to exploit extensive areas of newly discovered alluvial gold. Approximately 20 - 30 million ounces of gold were produced from these operations before the easily won alluvial gold deposits were largely depleted. The Tapajos region has had little exploration by modern exploration methods compared to any other equivalent gold fields in the world. The gold occurs in sulfide veins developed in shear zones within Proterozoic granites. Gold grades vary from approximately 15 g/t in the hard rock veins, to up to several ounces per tonne in the supergene weathered upper portions of the veins. Goldbearing vein zones in the weathered profile are free digging. In addition, tailings dumps from previous mining operations contain gold grades of approximately 1 g/t. Metallurgical test work conducted to date indicates that gold recoveries of at least 70 per cent can be achieved via gravity concentration. Gold Anomaly, via its 100 per cent owned Brazilian subsidiary, Gold Aura Do Brasil Mineracao Ltda (GOAB), plans to mine the tailings and weathered vein material by open cut methods to generate a quick cash fl ow and to provide a better understanding of the mineralisation as part of a feasibility study for mining the underlying sulfide zone mineralisation (see Figure 2). Mining will utilise locally hired excavators and trucks and ramp up to a rate of 100 tonnes per day. To treat the gold-bearing material, GOAB has purchased an integrated 'state of the art' gravity concentration processing plant from Gekko Systems of Australia. The processing plant includes a scrubber for clay and oversize removal, coarse gold gravity separation via an inline pressure jig and an inline spinner; and fine gold gravity separation via a Falcon Concentrator. The plant is expected to be operational by late 2010. This is an ABSTRACT ONLY. No paper was prepared for this presentation. 

Aug 1, 2010

By C Young

The identification of Critical Risks, their associated Critical Controls, and the implementation of processes to ensure their ongoing management can be difficult and resource intensive. Answering the following Critical Risk Management related questions can be challenging: • What is a Critical Risk? • What is a Bow-tie Analysis and when should it be used? • What is Critical Control? • How is the effectiveness of a Critical Control assured, and how is this measured? • Who is responsible for managing Critical Controls? • What are the implications if a Critical Control is not effective? It appears that in the mining industry’s efforts to implement the Critical Control Management Process outlined by the International Council on Mining and Metals (ICMM), instead of embedding an integrated, well understood, value adding process, we have instead created a resource hungry monster that is poorly understood by numerous layers of the organisation.

May 5, 2022

By Ross R

Although mining is an old industry its management is quite a new science, and its complications are now being recognised as demanding expert knowledge in many branches of technical and professional education. Not the least amongst these isaccountancy, for probably its most important problem is "How to control the expenditure." Unlike most businesses a mining company stands almost entirely in the light of a purchaser in the world's markets, and not as a seller, except say for product so the established and perfected systems of modern industries cannot be adopted for mining purposes. For this reason it has been left for late years to consider the matter seriously, and now a number of well-managed concerns have devised costs systems to suit their own requirements.Very little, however, has been published and even that is disjoined and difficult to make use of. Some of the costs systems in vogue, although elaborate and imposing, are not of very great value for keeping check on wasteful expenditure, or for displaying the commercial effect brought about 'by any particular change in practice, or by an addition or alteration to a portion of existing plant.

Jan 1, 1911

By C Young

In the vast expanse of Western Australia’s mining sector, a critical issue has come to light: many mining operations overlook the power of a Broad-Brush Risk Assessment (BBRA) to uncover their critical risks. This oversight has led to a cascade of challenges, where some mining endeavours find themselves grappling with: - Unidentified and unmanaged fatal risks, casting a shadow of uncertainty and heightened compliance risks. - A bewildering landscape where the concept of critical risks remains enigmatic, with some mistaking the risk register for the BBRA. - A fog of confusion surrounding the guardianship of these critical risks, leaving safety responsibilities blurred and undefined. Yet, the solution lies within our grasp. An effective BBRA empowers organisations to: - Pinpoint with unwavering certainty every ‘true’ critical risk. - Clarify ownership for each critical risk, ensuring accountability and swift action. - Create a prioritised roster of critical risks, illuminating the path to safer operations. - Lay the foundation for essential follow-up actions like bow-tie analysis, the identification of critical controls, and the fortification of the safety and health management system. Join us in this presentation, where we delve into the heart of an industry-leading BBRA process. Discover practical insights that will enable your organisation to craft and implement BBRA strategies, bridging the gaps in your journey toward preventing fatalities and fortifying safety protocols.

Apr 16, 2024

Over years of exploration the massive and tabular orebodies in the area to the South West of Western Areas Gold Mine had been assessed as containing about 50 million ounces of gold û a world class orebody. Planning initially was for a surface and subvertical shaft system to exploit this area but because of cost, a single lift shaft to an area which could be accessed ex Western Areas was planned to intersect the reef at 2760 metres. It was also planned to mine out the shaft pillar area long before the deep shafts would reach that position. This is not the normal practice in South African Gold Mines. The stoped out shaft pillar was backfilled to minimise movement in the shaft sites. The result of a competitive tender/adjudication process was that Cementation Mining û Skanska won and was awarded the R192 million contract to sink the Main and Ventilation Shafts on 15 June 1995. On 1 April 1999 Western Areas and Placer Dome SA formed a Joint Venture, which now owns and operates the mine on which the South Deep Shafts are situated. This situation prevails today.

Jan 1, 2002

By C Sylvestre

For the last 50 years, traditional safety management has improved safety performance by: • 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). Although these approaches certainly have merit, and may be part of an overall solution, they are not enough to prevent many modern-day 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 M Tayebi-Khorami

There is an increasing trend in the extraction and development of copper resources from complex deposits. The complex deposits pose mineral processing challenges, as they often contain low grade copper ore, relatively large quantity of clay minerals, complex texture, very fine disseminated ore, high amount of pyrite, and high level of impurity elements such as arsenic. With the amount of arsenic in concentrates increasing and with environment, occupational health and safety regulations becoming more restrict, there is a need for a processing method that results in no arsenic emissions and captures all arsenic while immobilizing it in a compound that is stable under a wide range of conditions, so it is suitable for long-term disposal. Some development work has been undertaken to examine the most effective arsenic treatment option for complex orebodies that contain arsenic, but a technically robust and economically viable option has not yet been developed. Previous research has demonstrated the possibility of separating arsenic-copper sulphides from other copper minerals by controlling the potential of the flotation pulp in the single mineral systems. The selective flotation of enargite from copper sulphides in a real complex ore system was studied by Tayebi-Khorami (2016), which is summarised in this paper. CITATION: Tayebi-Khorami, M, 2018. Arsenic in complex orebodies, in Proceedings Complex Orebodies Conference 2018, pp 132–134 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By P Stoker

The need for quality assurance and quality control (QA/QC) in the sampling and assaying of minerals is fundamental to the reliability and confidence of a mineral resource estimate, reserve estimate and possibly profitability of a mine. In spite of this, QA/QC practices in the mining industry are commonly applied poorly, or misunderstood. As New Leaders, we should aim to correct the poor practices and become fully informed on appropriate procedures. This paper uses worked examples that show the usefulness and importance of best practice QA/QC procedures. Fundamentals of reviewing the performance of the laboratory by examining the results of client inserted standard reference material (standards), blank material and duplicate samples are discussed. To do this, three examples from Australian data sets have been used. For each example, simple and efficient plotting techniques are suggested with subsequent evaluations of each plot. The first case study compares the results of internal standards from a laboratory with blind standards (where the expected value is unknown to the laboratory) submitted by the client. It was demonstrated over time that the laboratory was unintentionally analysing the internal standards in a different manner to the remainder of the sample batch. In this example, not understanding the cause of a high negative laboratory bias could have led to poor understanding of the depositÆs grade and in the extreme a proposed mining operation may have reached operational stage with a subeconomic grade. The second case study discusses the quality of blank material submitted by a mining operation to monitor cross-contamination within the laboratory. The blank material contained background levels of the element under investigation. This created uncertainty in the assay results, which could have led to the need for additional assays and drilling programs. Finally, the third case study demonstrates the use of the relative paired differences (RPD) technique to cross-validate the results from duplicates and repeat analyses from two laboratories. The three examples given show either laboratory or operational error. If left undetected, each example could have had serious implications for the mineral resource estimate and ultimately, the mining operation. These examples are not isolated occurrences; poor QA/QC practices are an industry wide problem exacerbated by rapid staff turnover and increased contractor positions on-site. New Leaders must be equipped with a thorough grounding in QA/QC best practices to improve its application and confidence in the results of sample analysis.

Jan 1, 2009

The celebrations which took place in 1986 to mark South Australia's Jubilee 150 served to focus attention on all aspects of the State's heritage. Until that time the sites and relics of South Aus- tralia's early mines had been generally neglected. Marked by the ruins of enginehouses and littered with the remains of the massive technology of the Industrial Revolution, these sites have now been recognised as containing the threads of a fascinat- ing story. In the early days of settlement the economy of the Colony was based on land and farming. Droughts caused periods of economic depression which were alleviated by chance discoveries of gold, lead, silver, and copper ore. Some of the mines which were opened on the copper deposits were the largest in the world at that time and their names well-known throughout mining circles. Working by hand with primitive equipment, the early miners excavated vast networks of shafts and stopes often extending to great depths: at Moonta- Wallaroo Mines for example workings extended to 860 m below ground. Because of the presence of underground water, mining to these depths would not have been possible without the Cornish pumping engine. Operated by steam power these massive engines and their associated equipment were transported from Cornwall by clipper and delivered to the mines by bullock cart. At this time the engines were at the peak of their devel- opment and, although expensive to import and install, they were highly reliable: the engine oper- ating Hughes pump at Moonta worked continu- ously for sixty years without a major breakdown.

Jan 1, 1987

Coal mining in the Bulli seam in the Southern Coalfield in New South Wales has experienced the dangers of outbursts of coal and gas. These incidents present a major risk to the safety of mine workers and consequently a threat to the overall viability of the mining operations. Since the occurrence of a major outburst incident in the South Bulli Colliery in 1991 involving three fatalities, the primary contributory factors associated with coal/gas outbursts in the Bulli coal seam have been identified and a strategy for the management of the outburst risk has been formulated by the cooperation of mine operators, mine workers and the Department of Mineral Resources. Utilisation of risk management techniques in combination with modern gas drainage technologies and geological control methods have led to the formation of this effective outburst management plan. Clause 15 of the Coal Mines (Underground) Regulation 1999 in NSW has made it mandatory in an area of outburst to carry out mining in accordance with a code or guidelines developed for mining in outburst prone areas (DMR, 1999). In this paper an outburst management system is discussed which was developed for collieries in the Southern Coalfield that brings together all the available information including past experiences and risk management techniques in a documented form in order to maximise safety of mine workers. It is concluded that since the introduction of the outburst risk management systems in the Southern Coalfield in 1994 considerable reduction in outburst incidences have been experienced.

Jan 1, 2003

By P J Savory

Ranger is a uranium mining operation located within one of the most environmentally sensitive regions of Australia. Geology has played an important role in mine planning, operations and rehabilitation since discovery of the deposits 25 years ago. The Ranger orebodies have a reserve total of 166 300 tonnes of U308 including 90 400 tonnes of U308 at North Ranger. At current milling rates these reserves give a mine life greater than 40 years. The uranium is hosted in Lower Proterozoic rocks of the Cahill I ormation and is associated with strong chlorite alteration. In pit grade control involves the use of calibrated probes and a radiometric truck discriminator allowing fast, accurate grade determination of material. Ore is defined at a cut-off grade of 0.2 per cent U308. Mineralised material is defined by the Uranium Mining (Environmental Control) Act 1979 (UMEC Act) at a grade of 0.02 per cent U30s. Natural water levels in the #1 Pit area vary as much as 7.5 metres between wet and dry seasons. Ground water inflow into the pit during the dry season is 600 m3/day. No significant slope failures have occurred in the pit. The environmental impact of mining operations is constantly monitored. Rehabilitation of non-mineralised stockpiles is ongoing. This paper discusses the interaction between geology, hydrogeology, rock mechanics and grade control with the present mining operation.

Jan 1, 1994

By A Turns

In a survey conducted by symplexi with underground miners in Australia; 78 per cent of participants believed that ‘safety’ is all about people. If ‘safety’ is about people, then is the mining industry focusing on the wrong thing? It would be fair to say that the mining industry is heavily systems focused. Companies develop a safety management system and use this to show regulators that they comply with legislation – however, that is only half of the picture.

May 5, 2022

By J Stiefenhofer

"*This is an abstract only*Construction of geological models for kimberlites has historically largely been based on visual volcanic textures and features, with chemical data only collected on an ad-hoc basis depending on the level of perceived complexity observed in the geological data. The focus of this paper is a high-level view of the impact an initial absence (or lack) of relevant chemical data had on two kimberlite resource models as well as how the magnitude of the problem increased once the resource estimation process commenced (Stiefenhofer, 2013). The impact of ignoring chemical data on a project assessment where micro-diamond estimation techniques are employed, is also discussed. Resource estimates based on micro-diamond data are critically dependent on the use of the correct geological model since stationarity of the size frequency distribution is key to the generation of correct grade estimates. A multilevel approach is advocated where the volcanological/visual model is verified using chemical data and both are in turn verified by the diamond data.CITATION:Stiefenhofer, J, 2013. The use of chemical and metallurgical parameters to enhance the economic value of kimberlite resource models, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013, pp 101-104 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 29, 2013

Hindustan Zinc Limited (HZL) is one of the leading base metal producers in India. It operates a two-smelter Complex at Visakhapatnam, Andhra Pradesh. At this zinc-lead smelter zinc is manufactured by the conventional hydrometallurgical route and lead is produced by Blast furnace technology generating residues or wastes which contain substantial quantities of metal values. Disposal of such wastes is a problem in any non-ferrous industry. Both the stringent environmental regulations and the changing industrial scenario emphasise the need for industrial research to find economically viable and environmentally friendly technologies to recover the metal values from these waste materials. The in-house R&D Centre at Vizag Zinc Smelter (VZS) thinking globally re-engineered its activities and major thrust was given for converting waste to valuable metals and metal compounds. Basic analytical chemistry with the hydrometallurgical concepts has been adopted in developing these innovative technologies. In this paper attempts are made to provide a clear history of the different waste raw material, the process developed for each raw material and their superiority of over other parallel work. Most of the processes described here are pilot plant tested and under patenting. The process flowsheet, results obtained and advantages of each process are presented. This paper provides a consolidated approach through which the varied smelter waste materials can be processed with cost effective and eco-friendly innovative technologies. In-house R&D efforts at VZS with its contribution and achievement in converting æwastes into wealthÆ technologies are presented in this paper on the following the major thrust areas:recovery of zinc from liquid effluent; recovery of zinc from effluent treatment plant (ETP) gypsum sludge; production of highly pure electrolytic zinc metal powder from zinc bearing gypsum residue/sludge generated at the effluent treatment plant; hydrometallurgical recovery of copper as copper sulphate solution which can be used for CuSO4.5H2O, copper cathode/copper metal powder from copper-cadmium cement; recovery of manganese, lead and silver from anode mud generated at Zinc Cell House and 4-metal extraction/recovery of manganese, cobalt, copper and nickel from Indian ocean bed manganese nodules; recovery of zinc, lead, silver and sulphur values from silver concentrate residue generated at the froth flotation process; recovery of silver and lead as lead-silver sponge/lead-silver sulphide concentrate from lead bearing residues; recovery of lead, silver and copper from copper matte; recovery of antimony as antimony metal or lead-antimony master alloy from antimony bearing dross; and recovery of nickel and dimethylglyoxime from Ni-DMG complex.

Jan 1, 2000