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Two Variable Real-Time Algorithm for Cone Crusher Control

Sep 13, 2010

The Ocean Drilling Program (ODP) is the largest international geoscience project in the world, and the state-of-the-art drill ship, the JOIDES Resolution, is permanently at sea. Each year there are six scientific cruises (legs) which each last approximately two months. These legs are designed by geoscientists from the nineteen countries that subscribe to ODP.Australia and Canada presently share ODP membership under the banner of the AUSCAN Consortium. The benefits of Australia's involvement in ODP include internationalisation of Australian geoscience, advanced graduate training, and unique scientific investigations of the ocean floors in the Australasian region. In addition, visits to Australian ports by the ODP drill ship, the JOIDES Resolution, contribute up to $2 million per visit to the local economy. Amongst the many other aspects of ten years of scientific drilling, OOP has significantly contributed to our understanding of hydrothermal processes on the seafloor. To date, three hydrothermal sites have been drilled to date by the OOP, Snakepit (MAR), Middle Valley (Juan de Fuca Ridge) and TAG (MAR). Two more hydrothermal sites are scheduled for 1996.

Jan 1, 1995

By Hillis R

As part of BHP Iron Ore's policy and goal of achieving a high standard of environmental management within its operations, a protocol for mine closure has evolved. The need to demonstrate sound environmental management with respect to site decommissioning meant that a comprehensive, environmentally sensitive closure protocol was required. Within this framework, a four-phase protocol was developed, the first phase was the determination of objectives in relation to site rehabilitation and end land use. The second phase was the determination of the process required to achieve these objectives. The third phase was the application of this process in a site specific manner. The fourth and final phase was monitoring of the site with regard to the achievement of determined objectives. The protocol was originally developed to direct the closure and decommissioning of the Goldsworthy site in 1992. This being the first total site decommissioning for BHP Iron Ore. Since that time the protocol has been successfully utilised for the closure of the Yampi (Koolan Island) operations (in 1993/94) and the Shay Gap/Nimingarra Operations (in 1994/95).

Jan 1, 1996

Comparison of Discretised Population Balance (DPB) and Finite Element Method (FEM) Methodologies for Modelling Batch Gibbsite Precipitation

Sep 13, 2010

Societal expectations about how the industry operates and treats its people will be a key driver in the development of the Australian mining industry over the next 20 - 30 years (Moffat, Mason and Littleboy, 2009). Understanding these expectations will be critical in maintaining what much of the minerals industry calls its 'social licence to operate', or its public acceptance or approval. Yet what constitutes this social licence is poorly articulated, with little published research exploring the concept at a local operational level or at the national level in Australia or internationally. This research aimed to explore the societal expectations of the mining industry in Australia and test a participatory methodology to articulate them. Three workshops were conducted with a sample of 24 members of the 'Australian voting public' to explore community objectives for the onshore exploration and mining industry, and the underlying expectations for how the industry should operate in the future. Qualitative analysis of this data revealed three overarching objectives for the onshore mining industry held by participants. They thought that the industry should: advance Australia's national interests (including social well-being); minimise environmental impact, and; act in a socially responsible manner. Within each of these three key themes, or objectives, a number of tensions were evident in the views of participants regarding the trade-offs they are willing to make to secure economic benefit from mining, as well as the basic conditions for socially acceptable mining. These data provide an insight into the conditions for a national social licence in Australia for the mining industry, and the means for its realisation.

Jun 1, 2010

By W C. Burton, J S. Kuszma, T O. Aspinall

The environmental impact of mining and evolving environmentallegislation has received increased attention worldwide in the last two decades (Bradfield, Shultz and Stone, 1996). The potential impacts associated with unstable spoil dumps from mine operations is the focus of concern both by the mining industry, environmental regulatory agencies and members of the public. Engineered slopes of mine spoils may be stable at the end of construction, but they can deteriorate over time. There is thus the need to increase the base of knowledge on the existing practices of spoil dump design and rehabilitation. Efficient engineering design and systematic economic evaluation of spoil dump reshaping techniques for mine rehabilitation assists in maintaining the expected standards of environmental compliance. As part of the overall approach for effective engineering design ofspoil dumps, a comprehensive, computational and efficient tool isrequired for assessing the economics and productivity of existing spoil dump reshaping practices for efficient mine rehabilitation. Such a design tool is useful in linking current spoil dump environmental management practices with engineering design planning and economic impact evaluation. This paper identifies the processes for the economic impact evaluation for existing spoil dump reshaping practices and proposed final site dump designs. Selection of an efficient spoil dump design at optimum costs will ensure operational efficiency. A case study is presented identifying economic impact evaluation in earthmoving equipment selection and the costs involved for the reshaping of spoil dumps to that of varying final site designs.

Jan 1, 2000

By G P. Bates

The rationale for the design of the Emergency Egress (escape andentrapment) strategy for one underground metal mine has beenpreviously described (Brake, 1999). Two of the key conclusionsfor this mine, which is equipped with 30 minute oxygen-generating self-contained self-rescuers (SCSR), were the need to ensure no person is ever more than 750 m from an emergency refuge station (ERS) and that it could take up to eight hours to rescue workers from undergroundå. These conclusions were based on a number of considerations including the non-availability of a credible, æpersonalÆ entrapment procedure at the workplace, the duration of self-contained self-rescuers when used for travel, the need for rapid æclearingÆ of mine personnel to effectively and safely target mine search and rescue resources and the maximum time to either put a fire out, or to rescue affected personnel. As there is no Australian standard for refuge stationsç (or for self-rescuers), this paper follows with guidelines for the location and specification of both fixed (permanent) and relocatable Emergency Refuge Stations (ERSs) that may be applicable to other underground Australian metal mines.

Jan 1, 1999

By L Forrester

The tube bundle system is an integral part of an underground coalmine’s gas monitoring system. The maintenance of these systems is vital to ensure the quality of the data produced. Integrity testing of the tube bundle lines is required monthly, as specified in Standards Australia AS/NZ 2290.3 (1990). The various forms of integrity testing are reviewed, including pressure testing and introduction of a known gas. This paper provides a recommended and standardised methodology for those techniques where none currently exists. A strengths, weaknesses, opportunities, threats (SWOT) analysis is performed. The parameters considered for the SWOT analysis include resourcing required by the mines, time for the testing to be performed, and quality of the results produced. The suitability of such integrity testing protocols to be used in a mine emergency situation is also evaluated.CITATION:Forrester, L, 2017. Tube bundle integrity testing methodologies, in Proceedings Australian Mine Vent Conference 2017, pp 129–136 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By Payne AR

The high cost of gateroad repairs and maintenance in U.K. longwall coalmining is a clear indication of the failure of permanent support systems to fulfill their prime function, i.e. control of strata movement. The main component of gateroad support is the pack, the design and materials of which have experienced an important development process during the last 10-15 years. More recently, research investigators have attempted to give a design basis to pack quality and dimension, and reference is made to two theoretical approaches. In the course of a current research programme based upon in situ monitoring, interim design recommendations have been proposed as a means of effecting improvement in support efficiency. Identification of characteristic deformation behaviour forms the basis of the recommendations made and the subsequent improvement in gateroad performance reported.

Jan 1, 1986

Bioleaching of E-Wastes

Sep 13, 2010

Research on the Differential Flotation of Iso-Floatable Lead-Zinc Sulfide Ore

Sep 13, 2010

By R Salmon, C Jones

This paper examines the recent trend towards sustainability reporting and the application of the Global Reporting Initiative (GRI) æSustainability Reporting GuidelinesÆ. It also reviews reporting in the context of the Australian Minerals Industry Code for Environmental Management, as well as the status of public sustainability reporting globally in the minerals industry. The public reporting of environmental, health and safety, social/community and economic performance has evolved over the past two decades. Initially, separate and to some degree disparate documents were produced to report performance in each distinct area. In the early to mid 1980Æs some organisations had begun to report their environmental performance through some minor commentary in their annual financial reports or through ætokenisticÆ leaflets, often used as public relations exercises. Due to more media coverage and an elevated level of public scrutiny, organisations are no longer merely reporting their good performance, but also their bad and indifferent performance. In recent years these once separate environment, health and safety and community public reports have further evolved to become more integrated, reflecting organisations embarking on the reporting of their progress towards sustainable development. The primary factor in driving the evolution of sustainability reporting has been the increasing influence of stakeholders. Two groups of external stakeholders that have had a significant influence over public sustainability reporting in recent years have been non government organisations (NGOs) and socially responsible investment funds. Significant expenditure is involved in the preparation and publication of a sustainability report however many organisations do not appear to have examined in detail what they are really trying to achieve from their public reporting process. It is important to establish objectives for the public reporting process to achieve maximum benefits. Without a framework of public reporting objectives, the benefits of the reporting process to the organisation will not be recognised and the considerable expenditure involved will be increasingly difficult to justify. We believe that by focussing on the process rather than the document, significant benefits to the organisation can be gained. Indeed, with a proper framework of objectives and targets, the reporting process can be used as a vehicle to drive organisational change, implement management systems and improve performance. An idealised framework for a public sustainability reporting process sees the organisationÆs sustainability policies drive the entire process and determine the sustainability objectives. Specific targets are then set to realise those objectives. The targets will govern performance indicators that should be used to measure the success of target achievement and which will also define what data need to be collected. Evaluation is a key component of the reporting process to measure the success of target achievement and progress in realising objectives, as well as review the need for new targets to be set. The actual production of a public document is only one, albeit important, component of the overall reporting process. The challenges that lie ahead for sustainability reporting primarily relate to the integration of environmental, social and economic performance reporting as organisations integrate their approach to these areas. This will only happen as the culture of an organisation changes to not only accept the principles of sustainable development but to implement those principles in daily operations. The reporting process has the potential to drive that cultural change by communicating the organisationÆs sustainability objectives and setting challenging targets for their realisation. Public sustainability reporting will only achieve its maximum value when it forms an integral part of an organisationÆs sustainability management system and culture.

Jan 1, 2002

By Silitonga M

Generally, the acceptable parameter for predicting the intensity of ground vibration due to a blast is the amount of explo ive u ed and the distance from the explo ion. A eries of closely controlled tests were carried out and it was observed that the degree of confinement or burden of an explosive charge play an important role in the variation of the transmitted magnitude of the shock wave through the ground.The intensity of the shock wave increases with burial depth or with greater confinement of an explosion until a critical depth is reached.Beyond this critical depth, the magnitude of ground vibration remain constant. This is an important finding, which explains the anomalies between the expected level and the monitored ground vibration in a particular situation.

Jan 1, 1984

New Developments in Spirals and Spiral Plant Operations Records indicate that spiral separators have been utilised in mineral separation for over 100 years. The Spiral's predecessor, the sluice, has been in use for centuries in different forms and a spiral can be thought of as a sluice wound around a column. The spiral separator is distinguished from the straight sluice, and other flowing film separators, in uniquely introducing centrifugal motion. The elegance of the spiral concept was embraced due to significantly improved separation efficiencies, ease of operation and tolerance of variation in feed conditions. Advances in spiral technology have improved the metallurgical performance, modernised the materials of construction, increased unit capacities and simplified operation. These advances have ensured that spirals continue to play a major industry role amidst other advancing and competing technologies. Recent developments in spiral and spiral plant technology include: the launch of the VHG spiral model, specifically aimed at feeds with very high levels of high-density mineral particles; the introduction of a high capacity wash water spiral model; and innovations in feed stabilisation and control. Details of these developments are presented together with the resultant operational benefits including feed stabilisation, product control and improved metallurgical performances.

Sep 13, 2010

The relationship between comminution testwork results and the milling circuit that is subsequently selected is not a direct one and frequently involves recourse to databases of past test results. This in itself reflects the lack of a systematic engineering approach in the design process. This paper reviews comminution tests for SAG mill design in an attempt to identify where the essential information comes from that will be used in mill selection. The conclusion is that results from traditional test methods, including obscure and little used procedures like the Mokken test, are more valuable from an engineering perspective than parameters for breakage rate based modelling. Suggestions are made on ways in which existing test procedures can be enhanced in order to generate parameters that can be directly related to characteristics of the milling circuit being designed.

Jan 1, 2002

By M Lentz

This paper will discuss the issues associated with blasting in an urban mining environment that have been addressed by Winstone Aggregates at the Mt Wellington Quarry. These issues include - control of vibration and air overpressure, repeatability of shot performance, fragmentation on an extremely low maximum instantaneous charge, compliance with Territorial Authority regulations and perception. Over the last two years, in order to address these issues, Winstone Aggregates have undertaken a programme of continuous improvement, which has included; ò implementation of new technology; ò revising site procedures; ò conducting an investigation into the structural response of local buildings; ò investigating safe extrapolation; ò extensive public consultation; ò establishing credibility during the consent process; ò identification of perception issues; and ò building relationships and trust with neighbours. The issues addressed at the Mt Wellington Quarry have increasing significance for traditionally rural mining operations, as the input of the local community being urban or rural, increases. New and existing operations have the potential to adopt best practice now, building trust with the community and raising the profile of the industry.  

Jan 1, 1999

By K Broadley

Risk and dispute resolution are linked. Dispute resolution techniques are brought to bear on a dispute - which is an outcome of a risk being wholly or partially realised. There has been an increasing awareness by business of risk as a component of doing business. There is an accompanying awareness of the need to manage risk - including legal risk. Many companies have undertaken a systematic review of their potential risks and endeavoured to put in place systems to help to avoid or manage risks. A legal risk management program will not prevent disputes arising. However, such a program should prescribe how that dispute will be managed. The management of the dispute will involve consideration of the dispute resolution procedure to be adopted. The most appropriate processes will take into account the practical, personal and commercial considerations surrounding the dispute and be as efficient, cost-effective and user friendly as achievable in the circumstances for the benefit of all the parties. Carrying on business in South East Asia, whether as an explorer or a mining operator, brings additional considerations to bear in legal risk management and the dispute resolution process. A significantly different perspective is required due to the varying nature of the legal systems in many South East Asian jurisdictions. These jurisdictions often have relative uncertainty as to the law. This impacts on the dispute resolution processes and also raises further timing and cost issues. The authors contend that this is all the more reason to endeavour, as practically as possible, to adopt a legal risk management and dispute resolution profile which will provide business with the greatest prospects of maintaining control of the dispute resolution process. This presents a greater chance of a successful outcome to the dispute. In these times of increasing pressures on profitability because of low mineral prices, all costs of a minerals business are being reviewed. In such times, a significant legal dispute may have even greater potential to adversely impact on the companies concerned, together with the careers of the people involved. In this paper possible approaches to managing disputes and a case study a legal dispute in which Freehill Hollingdale and Page were involved are discussed. The dispute concerned an international mining company developing a gold mine in Indonesia and one of its contractors in Indonesia. Described is how that dispute was resolved. This achieved a very satisfactory result for the client - all things considered. Given the æadditionalÆ problems associated with ascertainment and enforcement of ærightsÆ in South East Asia, the longer the parties can retain control over their dispute the better off they will be. For this reason, the authors set out in this paper the main additional dispute resolution tools available - that are appropriate for use throughout South East Asia.

Jan 1, 1999

By R J. Worland, D Bowyer, J L. Mauk

The TerraSpec is a compact field portable mineral analyser that uses non-destructive reflectance spectroscopy for mineral identification. The instrument uses and measures infrared and visible light that is absorbed by certain covalent and molecular bonds (AlOH, FeOH, MgOH, CO32-, OH, H2O and NH4) within the lattice of a mineral at specific wavelengths producing an absorption spectral profile. A variety of minerals can be detected including clays, micas, carbonates, and hydroxides as well as some sulfates and silicates. However, not all minerals are detectable, such as quartz and feldspar. Alteration minerals replacing volcanic rocks have been studied for several epithermal prospects in the lower Waitekauri Valley (Sovereign, Jubilee, Scotia and Jasper Creek) and a geothermal field in the Taupo Volcanic Zone. At the Sovereign, Jubilee, Scotia and Jasper Creek prospects previous XRD investigations determined well developed clay mineral zonation with illite in the west (Sovereign and Jubilee) grading into interstratified illite-smectite (Scotia) and smectite (Jasper Creek) to the east. Although the percent of illite within interstratified illite-smectite could not be determined and some illite-rich illite-smectite (>90 per cent illite) and some smectite-rich illite-smectite (>90 per cent smectite) could be misidentified as illite or smectite respectively, the TerraSpec survey determined the same zonation of illite to illite-smectite and smectite. Common chlorite, rare calcite and local kaolinite were also detected. At the geothermal field, the TerraSpec was primarily used to determine the occurrence of kaolinite, dickite and alunite, which form in acid conditions. Widely spaced (every 50 to 100 m) XRD results are in excellent agreement with closely spaced (every 5 to 10 m) TerraSpec results that further determined the occurrence of these minerals in previously unrecognised intervals. It also determined the occurrence of zoned smectite, illite-smectite, illite, and chlorite alteration. Overall, the TerraSpec is a rapid mineral identification technique that is very useful in delineating the occurrence and distribution of certain minerals in both epithermal deposits and geothermal fields. Although the TerraSpec cannot detect as many minerals as XRD, the TerraSpec allows data collection at a sampling scale and speed (real time) that is not practical by XRD.

Jan 1, 2006

Modelling and Simulation to Design a Flotation Circuit for Gold Concentration

Sep 13, 2010

æSustainabilityÆ is one of those words that has gained more usage in popular discourse than in the dictionary. In fact it is not in many dictionaries at all. Typically, given this, it also seems to mean different things depending on whose lips it emerges from. It is now like a code word in that if people say it, you donÆt have to think about its meaning; it is just æthereÆ and is taken for granted. This is a problem for the mining industry as we are now using the term too and to be effective in what we do, we need to have a reality check and see how those outside who have views on us (æstakeholdersÆ maybe) use it. The core issue seems to be æsustainability of whatÆ: the industry?, a company?, the global environment?, particular ecosystems?, the community? At these levels, the term seems almost meaningless. If we do not even agree on what it is, at least broadly, our communication and possible partnerships for going forward will be difficult to say the least. One reference to æsustainÆ in my thesaurus is: æTo keep from failing during stress or difficultyÆ. This may be a clue to something approaching a common notion. I suggest that to use æsustainabilityÆ we make the following assumptions:that we are talking about human activity aimed at making a living that has an impact on the natural and social environment; that humans must make a living (though what this needs to include is problematic); that the impact of particular activities has been problematic to date and needs to be monitored, altered, stopped, etc; that there is stress on both social and natural environments; and that change can be effected in order that particular activities such as mining minimise their negative effects and maximise their positive. This is why we are taking part in sessions such as this one today. Two more initial observations: First, it strikes me that even with the above assumptions laid out, æsustainabilityÆ and æsustainable developmentÆ are too abstract and general as concepts. We have to break these high and mighty ideals down into workable, bite-size chunks, into practical ways of dealing with the world outside our sites and companies. Second, sustainability, on both sides of the fence, too often focuses on nature and environment as though they are independent of people and community. I would argue, perhaps provocatively, that sustainability is primarily a people issue and has to be tackled as such. I want to look at the overall climate for business today and how it has responded before I return to what we can and need to do as the mining industry to make æsustainabilityÆwork.

Jan 1, 2002