Search Documents

By I M. Howard

With the bell-less top (BLT) charging system replacing the centuries old double bell charging method, the furnace efficiency has been greatly improved together with considerable reduction in the furnace down time and operational problems. But still there are many draw-backs which need further attention to achieve better efficiency and operational effectiveness. The performance and operational problems of the BLTs have been highlighted and possible solutions to overcome some of the major problems are discussed.

Jan 1, 1999

This paper identifies the challenges and opportunities for mining companies and communities in investing in human rights compatible, credible, effective and representative company-community relationships.   The paper draws on the work of Professor John Ruggie, Special Representative to the United Nations Secretary General on Business and Human Rights, and his Protect, Respect and Remedy framework for business and human rights, The CDA Collaborative Learning Project, and the experience of Oxfam Australia. This paper begins with the premise that Australian companies commence operations offshore with high expectations and a willingness to work harmoniously with local communities. However, as companies increasingly engage in global operations - particularly in weak governance and conflict zones - the challenge to establish and sustain rights compatible, meaningful, corporate community relationships and grievances mechanisms becomes both more complex and necessary. Establishing trust and honouring commitments made to communities, including legacy issues, is a critical component in good corporate community relations.   The second part of the paper will identify some of the impacts and challenges of mining that need to be addressed in corporate community negotiations and consultation. Respect for indigenous people's rights and their right to give or withhold consent for a project to proceed is increasingly evident, as is the growing global expectations with regard to revenue transparency. As such, key challenges include: grievance mechanisms; free prior and informed consent; transparency and accountability; the gender impact of mining; resettlement, compensation and benefit sharing; and security issues.   Finally, the paper will provide practical guidance to companies on how to establish effective corporate community relationships. It will include examples, such as human rights impact assessments, gender impact assessments, and establishing local level grievance procedures. The paper will include an Oxfam Australia case study of a dialogue mechanism at Tintaya copper mine in Peru.

Jun 1, 2010

India is on fast economic growth. Even in the turbulent years of global crisis, it could achieve a growth of over eight per cent. In recent past, Indian Government has been contemplating a faster growth in all the sectors of economy so as to make the nation an economic power in the world.Steel is a versatile material. It has its role in most of the major industrial activities, such as infrastructure, automobiles, urbanisation, consumer durables and other. In other words, steel is a part and parcel of industrial expansion, urban and rural development. It is rightly admitted that steel acts as pillar of any development model. Volume of steel consumption is the barometer which measures economic progress and/or industrial status of any country.India and China are the two countries in Asia which have the significant impact on the global steel industry. Of course, China is much ahead of India in consumption level of steel.

Dec 6, 2010

By D R. Swinbourne, T Lehner

Study of the distribution of minor elements between copper matte andfayalite slag is important in determining appropriate methods tomaximise the recovery of valuable metals and the rejection of harmfulelements. Boliden Mineral AB operate a large copper smelter in northern Sweden, where they had noted that the loss of silver to the slag in the settling furnace appeared to be a direct function of the tin content of the slag. This work was aimed at determining whether or not this was a cause-and-effect relationship. Copper matte containing approximately 50 wt per cent copper and small amounts of silver and tin was equilibrated with silica-saturated fayalite slag at 1250¦C, then quenched. The matte and slag were then analysed for their silver and tin contents. It was found that there was no relationship between the silver distribution and the tin distribution. The silver matte/slag distribution ratio had a value of 120 ¦ 40 while that for tin was 2.8 ¦ 0.3. It is suggested that the most likely cause of the relationship observed at the Boliden smelter was matte entrainment in the slag.

Jan 1, 1999

By F Djukic, T Fisher, G Irving

Questionnaires were sent to 12 underground metalliferous mines in Queensland to enquire how these mines control diesel emissions from mobile diesel engines used underground. Where responses or controls were absent, discussion has been provided. A significant finding concerns secondary ventilation design rates. Some mines were designing ventilation rates to meet the superseded Mines Regulation Act of 1989 which required 0.04 m3/s/kW. The current Queensland Mining and Quarrying Safety and Health Regulation (2001) is risk based. In line with other jurisdictions, including New South Wales (NSW) and most Provinces in Canada, a minimum ventilation rate of 0.06 m3/s/kW is acceptable. However, this design ventilation rate will vary in practice depending on the diesel engines and controls. Dedicated ventilation engineers and technicians should be appointed to evaluate the effectiveness of the ventilation system. Personal exposure monitoring is required to confirm that exposure standards are not being exceeded. The primary control practice should be to reduce the emission at source. This can be ensured by purchasing low emission (Tier 2, Tier 3) equipment. In addition, the use of ultra low sulfur fuel (et al, 2002). Diesel fuel with a low aromatic content such as Eromanga diesel fuel will also mean employees are exposed to lower levels of poly-cyclic aromatic hydrocarbons. These controls should be carried out in parallel with good maintenance practices. Preventative maintenance should be programmed and emissions be routinely tested, including both gaseous and particulate pollutants and compared against defined criteria. According to McGinn, 2002, there are a number of fundamental tools necessary to carry out preventative maintenance. These are outlined in maintenance guidelines and best practices for diesel engines in underground mining produced for the Diesel Emissions Evaluation Program (DEEP). An effective diesel emission management system needs to be fully integrated within the Safety and Health Management System. These requirements are further discussed in this paper.

Jan 1, 2007

By J Lööw, M Nygren, E Segerstedt, L Abrahamsson

The purpose of the paper is to discuss socially sustainable development in the mining industry and the communities surrounding the mines. The discussions are based on results from a prestudy and literature review on mining and sustainable development conducted during 2013–2014 at Luleå University of Technology in Sweden. ‘A social licence to mine’ is important for the mining industry, but the social dimension is a relatively underdeveloped dimension when it comes to sustainable development in general and the mining industry in particular, one reason probably being the lack of effective methods for capturing social impacts. The mining industry and the surrounding communities face many challenges that provide both possibilities and obstacles to socially sustainable development; eg aspects such as gender, work conditions and cultural aspects. For example, a strong mining workplace culture and community identity can create strong cohesion but also lead to excluding certain groups, rejecting new ideas and reinforcing obsolete values. Other challenges include recruitment, as well as health and safety in relation to an increased use of fly-in-fly-out, contractors and automation of mining. Some challenges relate to the effects of fluctuations in the mining market. There is a lack of research that links attitudes, policies and activities within companies to their impact on the wider community, and vice versa. Future research should also include the development of methods and indicators for social sustainability relevant for mining – in other words: how do mining companies get ‘a social licence to mine’?CITATION:Abrahamsson, L, Lööw, J, Nygren, M and Segerstedt, E, 2015. How to get a social licence to mine, in Proceedings Third International Future Mining Conference, pp 125–136 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

One of the major changes in the resource industry in the nineties has been the re- internationalisation of the industry. The history of the resource business has been one of companies from the developed world utilising the cash flows from their operations to explore and develop mines in less developed regions of the world. This resource development has progressively generated wealth and economic development, which in tum, has led to a new generation of exploration and mining projects.   InSouth America, Chile had led the way in a mining resurgence, now closely followed by Argentina, Brazil, Venezuela and Peru. Although Chile has long had a significant copper mining industry, the pre-nationalisation phase was driven by American capital; the current phase has been spearheaded by RTZ - BHP at Escondida with Canadian junior companies, in particular, providing major speculative impetus. The Australian junior companies have not been significant in South America.   Although Canadian and USA exploration appears to be in decline, the mining industry, particularly in gold, is buoyant in North America. Interestingly, a number of listed and unlisted Australian companies are active, particularly in United States exploration.   Australian-based companies have dominated the South-East Asian exploration scene, especially in the Vietnam region. To date, the combination of political and legislative uncertainties have failed to lead to significant resource developments in this region. The area remains one of great potential, as exemplified by the exciting developments in Indonesia.   The Philippines has a history of mining, and this has been dominated by both local and North American operators. Both large and small Australian resource companies have a presence in the Philippines, and the development of the copper-gold potential could be impressive over the next decade.   The tales of the undeveloped mineral potential of China are probably rivalled only by the supposed strings of virgin Russian orebodies! Many Australian companies appear to have looked but few have chosen to proceed with Chinese developments. There seems little likelihood that China will, in the foreseeable future, rival South America as a target for Australian and North American resource capital.   Papua New Guinea has had an active, albeit chequered history in mining, with Australia long being the predominant source of exploration and development funds. The developing nation status of PNG has generated extreme uncertainty, with the current exploration scene all but dead. Most recently, the international flotation of Lihir Gold has tested the international and Australian investment community's commitment to PNG resource development.   The Australian exploration scene continues buoyant, although dominated by gold. The base metals scene is generating, on average, one significant base metal mine developed every couple of years. This is probably the fastest rate of significant base metal development in Australia's history.   The gold scene has been one of incredible dynamics, and there is no evidence that this momentum is waning. The development of new exploration techniques, together with a number of the companies reaching a critical size, has added to the momentum in the industry.

Jan 1, 1995

Flotation testing has been done at laboratory scale on hematite mineral and ore samples using stage additions of various hydroxamates. Chemisorption of hydroxamate species onto the hematite surface was inferred from the results, possibly involving both the undissociated hydroxamic acid and hydroxamate ion as maximum recovery occurred close to the pKa of the hydroxamic acid. Flotation testing on a specular hematite ore containing 40 per cent Fe and 42.5 per cent silica gave highest iron grades in concentrate at pH 6, in contrast to published data which suggested pH 9 as the optimum value for ore processing. Using octyl hydroxamate, a rougher concentrate assaying 67 per cent Fe at 51 per cent recovery was obtained using four stage additions of 50 g/t at pH 6. For lower grade concentrates still meeting the chemical analysis for pigment grade micaceous hematite (minimum Fe assay 60 per cent) iron recoveries of 80 per cent were possible for stage additions of 50 g/t octyl hydroxamate in the pH range 6-8.

Jan 1, 1999

By A Clark

When production targets are not being reached it is essential to determine what the operating problems are so that remedial action can be taken. It is also imperative that all persons who are part of the production stream within a mining operation know and understand what the operating difficulties and delays are so that corrective action is effective. This includes the supervisors, superintendents, planning team members and managers. A new approach recently adopted at Hilton Mine to help identify these operating difficulties has been to use short-term schedules and reports known as the Daily Shift Schedule Controls (DSSC), and the Daily Weekly Operating Reports (DWOR) respectively. These control elements have enabled management and supervisory staff to accurately identify labour inefficiencies and ultimately determine capital resources.

Jan 1, 1998

By J Harris, P Kirsch, D Cliff, M Spinks, S Goater, D Sprott

Fires are a common and recurrent unwanted event in the operation of open pit mines. In most cases, the causes of events such as fires are already æknownÆ but are either overlooked or not fully addressed in planning. Ongoing rapid growth of the global mining industry is creating a scarcity of skilled personnel, and high turnover within operations. This contributes to loss of corporate memory in risk management activities. RISKGATE« is an online risk management system designed to support and assist in the analysis of priority unwanted events in Australian coal mining operations. Funded by the Australian Coal Association Research Program (ACARP), RISKGATE« is a knowledge management program that delivers best-practice controls for unwanted events and assists operations in staying abreast of emergent risks and threats. RISKGATE« content has been primarily developed from an association of industry experts, and enriched with input from additional academic and technological resources. In mining operations, RISKGATE« provides a continuum of knowledge and best practice for risk identification, assessment and management. RISKGATE« will assist companies in improving safety performance, operational efficiency, operating practice and training. Here we present the RISKGATE« prototype as developed in 2011 for Fires, with a case study presented for the initiating event Fires on Mobile Plant.CITATION:Harris, J, Sprott, D, Spinks, M, Cliff, D, Goater, S and Kirsch, P, 2012. RISKGATE« - A case study in application to fires on mobile plant, in Proceedings Eighth Open Pit OperatorsÆ Conference , pp 49-54 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 18, 2012

The offshore Maui gas/condensate field was discovered by Shell BP and Todd on Services Limited in 1969. Subsequent appraisal drilling and negotiations with the Government led to a development agreement, æThe Maui White Paper' being concluded in 1973. Part of this agreement provided for the Government to take a 50 per cent shareholding in the field. The field is comprised of a double domed anticlinal structure containing two gas reservoirs at depths ranging from 2700 - 3000 m. Water depth is 110 m. The development plan called for two standalone steel platforms to be installed sequentially over a period of some years depending on gas demand. The first platform (MPA) was put in place in 1976 but difficulties were experienced with piling and drilling of the 12 (later increased to 14) wells did not start until 1978. First gas was piped ashore late in 1979.

Jan 1, 1994

By J Hudson

Autogenous (AG) and Semi Autogenous (SAG) grinding mills are the conventional selection for large-scale grinding circuits. It is accepted that these forms of comminution are not the most energy efficient available. This efficiency combined with escalating energy prices, steel prices and the requirement to process larger, lower grade deposits has necessitated that better comminution techniques are found to challenge the dominant position of AG/SAG mills in the grinding circuit. Recent advances in high pressure grinding rolls (HPGR), particularly in terms of roll surface protection have meant that, depending on the application, an economic alternative is available to the large diameter AG/SAG mills. Mining companies now recognise the potential benefits of HPGR and so they need proper assessment in the design of new or upgrade of existing grinding processes. Of course, the answer to the question AG/SAG or HPGR is not straightforward and the impact of the grinding process on the whole metallurgical process needs to be evaluated. Clearly this is a complex decision to make and requires substantial metallurgical knowledge, test work, and objective analysis. The perceived downstream processing benefits will differ between different plants depending on the ore type and processing conditions. The optimal design of the comminution circuit requires that a robust methodology is followed to objectively characterise the ore, size the equipment and determine the downstream processing benefits. The paper gives a brief comparison of the capital and operating costs for both grinding systems, and then outlines the appropriate test work that is required to make an informed decision.

Jan 1, 2006

By A B. Christie, F P. Bierlein

Lode gold deposits of the Western and Eastern provinces, South Island, New Zealand , formed as a part of the Cordilleran-style tectonism during Tasman/Tahua and Rangitata orogenesis along the Paleozoic-middle Mesozoic southern Gondwanan margin. These deposits, hosted by lower grade greenschist facies sedimentary rock sequences of the Buller, Takaka, Torlesse, and Caples terranes, universally show geological features that are consistent with the orogenic gold deposit model, and genetic features are generally suggestive of a metamorphic origin, with the possible exception of a magmatic fluid source for the mineralisation at Sams Creek. However, ore fluid chemistry in Mesozoic deposits of the Eastern province, particularly the low concentration of non-aqueous volatiles and the very dilute nature of the fluids, is uncharacteristic of most orogenic gold deposits; this must be explained by either a unique fluid source or fluid type, which we believe unlikely, or an unrecognised significance of relatively rare gas-rich fluid inclusions in the deposits. Absolute age data for gold deposits in both provinces remain equivocal, thus hindering definition of the exact temporal relationship between ore formation and terrane accretion, regional metamorphism, and magmatic arc emplacement. Mercury and antimony occurrences in subgreenschist grade parts of the Haast Schist may target the upper levels of unrecognised orogenic gold deposits. If low-grade, high-tonnage intrusion-related gold systems occur on the South Island, then they are most likely to be discovered in association with the small molybdenite-, scheelite-, or cassiterite-bearing quartz stockworks spatially related to the Karamea and Median batholiths.

Jan 1, 2005

By D Thomas

Geochemical data related to AMD for the West Coast and Southland regions have been collated into a relational database and GIS system. The types of information include; rock geochemical data, water chemistry data and aquatic macro-invertebrate abundance data. This information will be combined with eco-toxicology experiments to determine impact thresholds on aquatic ecosystems. Ultimately these datasets will be combined with remediation investigations to produce a Framework to assist decision making related to mine planning, consent and compliance.   Current geochemical research examines the controls on As concentrations downstream of gold mining areas and the variability of AMD from Brunner Coal Measure rocks. Assessment of factors that control the chemistry of Brunner Coal Measure AMD such as mine type, hydrogeology, geology, geochemistry and climate is in progress. Minerals that control the concentration of aluminium downstream of AMD point sources include alunite, jurbanite and various forms of Al(OH)3.

Jan 1, 2005

By D Yan, D Connelly

Beneficiation of magnetite is an integral part of the future of iron ore processing. Historically, the focus of Western Australian producers has been on exporting direct shipping ore (DSO) namely haematite. The future for new DSO resources is limited so companies are changing their emphasis into processing the very large, undeveloped magnetite ores in Western Australia (WA), using beneficiation to produce shippable magnetite concentrates. These magnetite resources require higher cost processing techniques such as fine grinding and beneficiation to produce saleable concentrates. This distinct difference, from the DSO ores, has led to the development of a number of new technologies. This paper reviews: the different techniques used for magnetite beneficiation and provides some case studies in the WA industry; the use of mineral liberation analysis (MLA) to describe the nature, grain size, occurrence and associations of the mineralisation;the consideration of coarse cobbing as a critical upgrading; the application of high pressure grinding rolls (HPGR) to save energy; how the field of magnetic separation has resulted in new machines with higher field strength (SLon Separators); ultra fine grinding requirements of magnetite concentrates; andthe application of reverse flotation to reduce silica in the concentrates.

Jan 1, 2009

By I Lamb

Past experience of ground settlement and groundwater monitoring for tunnelling projects in Melbourne has provided an appreciation of the value and importance to owners of establishing a broad baseline monitoring program of the ground surface movements and groundwater movements well in advance of the commencement of any excavation and tunnelling activities. For the Northern Sewerage Project (NSP) tunnels in the northern suburbs of Melbourne, a baseline monitoring network of ground settlement points and groundwater wells was established in early 2006, 18 months prior to the commencement of project construction, and has continued throughout the tunnelling and project construction activities. This baseline monitoring network provides insights into the superposition and interpretation of both tunnelling and non-tunnelling effects, such as seasonal effects, which result in ground settlement.In the case of the NSP the baseline monitoring and construction phase excavations coincided with several years of drought. The reduced rainfall developed overall downward settlement trends project wide that could easily be mistaken at the local site level to be construction effects if the baseline monitoring was not available to show otherwise. There are lessons to be learned from the NSP experience for tunnel projects where there are variable surface soil types and where project-specific settlement criteria are to be established for the protection of property prior to construction.This paper presents examples of the baseline monitoring, how the tunnelling-specific settlement was identified and determined, and what this means in terms of how settlement criteria should be established and set for project consenting and in the construction contract documents.

Mar 8, 2011

By M O. Tade, M W. Sze

The particle dynamics of a mixture of coal and zircon system wasstudied in a scaled-down cold model of an industrial kiln. Thefactors investigated in the study were rotational speed (N),zircon-to-coal feed ratio (B), coal particle size (dpc) and the angle of inclination (*) of the kiln. The technique used is the residence time distribution (RTD) method. It was found that rotational speed and angle of inclination are important parameters that affect the residence time of particles in the kiln. A mathematical model for predicting the mean residence time of particles in the rotary kiln was developed. Comparisons with reported models for such systems are discussed.

Jan 1, 1998

By C Gimber

Dust suppression is an important environmental control in most mining operations. The poorest quality water within a mine site is often used for dust suppression since it provides an effective means of reducing the volume of poor quality water. The ultimate fate of contaminants or salinity associated with water used in dust suppression is important to consider for optimising water management and assessing the environmental impact and life span and maintenance requirements of roads associated with dust suppression.The propensity for remobilisation of contaminants or salts depends on a range of factors such as the application rate, climate, road construction, water chemistry and soil geochemistry. This paper describes a typical study approach which could be used to assess the short- and long-term impacts of mine water application for dust suppression. The steps of the study are: reviewing the environmental setting, estimating water requirements for dust suppression, reviewing source water chemistry, developing a mass balance model and assessing the mobility and fate of contaminants with a geochemical model.This approach identifies which salt species are likely to form and whether they are prone to remobilisation. It is possible to quantitatively assess the risk of exporting contaminants or salt from roads and to refine the dust suppression strategy to minimise the environmental risk. The approach can be applied at mine sites to address regulator concerns, aid decision-making and improve the understanding of short- and long-term environmental risks.CITATION:Gimber, C, 2013. Assessing contaminant risk associated with the use of mine water for dust suppression, in Proceedings Water in Mining 2013 , pp 235-240 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

For years traditional optical microscopic techniques have been used successfully to carry out mineralogical studies on processing products. Essential information could be obtained by supplementing microscopic data with X-ray powder diffraction data, chemical analyses, etc. However, most of the time the mineralogists working on plant related issues, would supply qualitative information to the metallurgists, due to quantification not being possible in the available time. Since the late-80s, the use of semi-automated to automated techniques for mineral quantification has impacted positively on the use of mineralogy for optimising processing plants. Rustenburg Platinum Mines (now Anglo Platinum) were the first mining company to purchase a Qem*Sem in 1987. With the success achieved in quantifying the minerals in the concentrator streams of the Rustenburg Platinum operations, a second instrument was purchased soon after. These instruments have proven invaluable tools in understanding the flotation behaviour of the sulfide and gangue minerals in the various reefs of the Bushveld. Restrictions in the resolution of these earlier instruments, as well as the time involved in searching for and correctly identifying the fine-grained platinum-group minerals (PGM), meant that these investigations focused on the deportment of the more abundant base metal sulfides, rather than on the actual PGM. The Mineral Liberation Analyser (MLA), which became available in the late 1990s, was well suited to detect and analyse minerals occurring in trace amounts such as the PGM. Anglo Platinum was the first mining company to purchase such an instrument and now has fourteen systems operating at the AR Crown Mines site. One of the applications of these systems involves the study of feeds, concentrates and tailings from the various concentrators on a monthly basis. These routine investigations provide information on a variety of mineralogical parameters, including liberation, association, and grain size. Results are used to emphasise areas for improvement, and specifically underline those areas where improvements will have the most impact on recovery. After new or different technologies have been implemented, mineralogical characterisation of the different process streams is an essential component in the assessment of the impact of these changes on flotation performance. In addition, the knowledge is databased for future reference to draw trends across the various concentrators around the Bushveld complex, and is also used for comparative studies when plants experience high losses to tailings. Due to the success of these investigations the question was posed whether it was possible to obtain data on a daily basis, as compositing samples could hide the impact of daily events. Although the instruments currently used are suitable for a research environment, these are not ideal for mine-site implementation. For that reason Anglo Platinum, together with FEI embarked on a development program to develop a system that can be implemented on-site to measure the important mineralogical characteristics on a daily basis. Important requirements for such a system include time-to-data, ease of use and regular quality control. Highlighting some results from concentrator studies, the presentation will review the progress on the development of automated mineralogical techniques for fast, automated mineral measurements. This is an abstract only. No full paper was prepared for this abstract.

Sep 13, 2010

By G Smart, D Ward, J Grace

Ridgeway Gold Mine is part of Cadia Valley Operations which is wholly owned and managed by Newcrest Mining Limited. It is an underground sublevel cave (SLC) operation mining approximately 5 Mt per annum. Ore control systems at Ridgeway have been designed to deliver gold and copper metal production through focussing on the ore characteristics that impact on mine and mill performance and ultimately metal delivery. This is achieved using data collection and management systems which allow data to be collected digitally with æat captureÆ validation routines. These data form the basis for forecasting and on-going systems analysis which aim to accurately assess local in situ and drawn ore characteristics. Physical attributes of ore such as draw characteristics, brow conditions, visual grade estimates and draw point sampling are routinely recorded. Ore tracking and accounting systems monitor gold and copper grades, copper mineralogy, host lithology and ore sizing. These factors have material impacts on concentrator throughput and metal recovery. Draw point recovered grades are routinely reconciled back to design data to monitor and assess draw performance. Statistical variance controls are also employed to analyse mine and plant performance and guide actions.

Jan 1, 2003