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Mine rehabilitation is a sustainability issue that has been revisited ad infinitum; however, the persistent lack of demonstrated on-the-ground performance and an increasingly intractable rehabilitation liability in Queensland continue to erode the credibility of the mining industry and regulatory bodies. For at least ten years the need to change the current, process-based approach to rehabilitation to an outcomes-based approach has been apparent. The ISO 14001 series temporarily diverted attention from this important point, however it would appear the limitations of an ISO 14001 approach are now more widely accepted. It is proposed that a successful outcomes-based approach cannot be achieved without meaningful community engagement. The apparently intractable nature of the rehabilitation issue will continue to generate conflict and criticism unless all stakeholders are encouraged to participate in the process of developing robust and practical outcomes for rehabilitation. Sharing the responsibility will ensure the best possible outcome. It is important to recognise the valuable resources inherent in community groups, many of whose committed volunteers have considerable expertise in relevant areas. Community groups should not be seen as adversaries but as allies in the process of solving problems that affect the wider community. Several projects that can be seen as test cases for the engagement of stakeholders exist, and in this paper the process of achieving multiple stakeholder engagement in the context of Environmentally Sustainable Development is discussed.

Jan 1, 2002

The overwhelming weight of scientific opinion indicates that human activity is having a discernible and negative influence on the earthÆs climate system. The Australian Government, together with about 100 other nations, has accepted the findings of the Intergovernmental Panel on Climate Change third assessment report, released in 2001. This report was prepared by several hundred eminent scientists from all over the world, from various scientific disciplines and with differing opinions on global warming. The IPCC third assessment report contains a series of relevant, significant conclusions; for example, it finds that there is an increasing body of observations that gives a collective picture of a warming world and other changes in the climate system. Global average surface temperature increased over the past 100 years by about 0.6¦C. This may not seem much, but in the 900 years beforehand, the EarthÆs temperature remained relatively stable. The 20th century was the warmest of the past 1000 years in the northern hemisphere (there is much better information available from the northern hemisphere than the southern hemisphere). The 1990s were the warmest decade of the millennium in the northern hemisphere and 1998 was the warmest year. Although many factors influenced the EarthÆs climate, scientists are confident that greenhouse gas increases were the main factor contributing to global warming in the last 50 years of the 20th century. Increases in carbon dioxide, methane, troposhperic (lower atmosphere) ozone, halocarbons and nitrous oxide have all contributed to global warming. Combating climate change cannot be done without the cooperation of industry and the community at large. It is important that Government and industry work together to achieve greenhouse gas abatement while ensuring continued economic growth. The cause of the problem û the generation of greenhouse gas emissions û lies at the heart of the structure and size of modern economic activity. Greenhouse gas emissions are embedded in our way of life from our energy consumption patterns to the basic production of food. Moreover, the costs of the impacts of climate change to the earth will be potentially revolutionary, not merely evolutionary. It is in this light, acknowledging both the seriousness and nature of the problem before us that I want to reflect on the key drivers in the international climate change negotiations. A consideration of the past, present and future from what I see as the mid-way point in the process. In 1997, Parties agreed to adopt the Kyoto Protocol, which sets out mandatory targets for greenhouse gas emissions for developed countries.

Jan 1, 2002

By I F. Bell, K P. Hammerschmid

Well planned and executed environmental management plans can reduce life-of-mine operating costs and the need to deal with major environmental issues at the time of mine closure. With proper planning during the exploration, feasibility and execution phases of a project, final closure costs can be reduced. The reduction of closure costs should be considered during exploration and initial feasibility studies and when process facilities, waste rock dumps and tailings impoundments are designed. During the mining of the resource, closure cost reduction will depend on effective and efficient environmental management plans for ongoing land clearance, segregation of mine waste materials, management of mine site water and workshop wastewaters, and the establishment of progressive rehabilitation strategies. These issues are the responsibility of planning, production, technical support and maintenance personnel at an operating site. The successful implementation of environmental plans will ensure that all impacts are reduced and that closure issues with major cost implications are addressed prior to closure of the mine.

Jan 1, 1995

Heap leaching of copper sulphide and oxide ores' has been conducted at Rum Jungle since the end of 1965.A review of operations was made and this led to an examination of some theoretical aspects of copper sulphide heap leaching. Ox,ygen diffusion was indicated to be the factor controlling copper leaching rate at Rum Jungle and in other similar operations. Suggestions are made for measuring the heap leaching rate. Prediction of full scale operational results from pilot scale testwork are discussed.

Jan 1, 1969

By M Wimmer

LKAB operates two underground iron ore mines located in the northern part of Sweden, both using sublevel caving (SLC) as the mining method. Knowledge of the mechanisms of gravity flow is important since it affects both ore recovery and waste dilution. This paper describes results from a large-scale field test carried out at the Kiruna mine with a focus on gravity flow. It is part of Work Package 2 in the I2Mine project financed by the EU. A total of ten rings were blasted. Smart Markers based on radio frequency identification technology were used to monitor the gravity flow. An accurate delineation of the isolated extraction zone requires reliable detection of all recovered Smart Markers and precise knowledge of the 3D position of the markers within the burden. It was therefore necessary to carry out borehole deviation measurements (collar, alignment and trajectory). The blast performance was monitored by high-speed filming, near-field vibration monitoring and velocity of detonation measurements. Three-dimensional stereo images were taken from the drawpoint and the loaded bucket after each mucking cycle. Based upon that, fragmentation was assessed both in 2D and 3D. Furthermore, volumetric differences were determined at the drawpoint, which reflects the mobility of loaded material. For draw control, the Fe content is estimated by measuring weight and assuming a full bucket. The measured volume of rock in each bucket further improves this estimate. Possible flow disturbances occurring at the drawpoint were revealed by video recording. Two-dimensional laser scanning was carried out during mucking to track the position of the bucket and estimate the position and slope of the muck pile.The results from this test clearly show that the gravity flow in the large-scale sublevel cave in Kiruna mine is often of disturbed character. Standard draw occurred only in three rings and shallow draw in the remaining seven rings. In five cases, shallow draw developed towards standard draw, but occurred at rather late stages during extraction (70–125 per cent). The maximum width of the draw varied between 10 m and 13 m except for one ring (6 m). The draw reaches the cave rather early (5–25 per cent extraction) in shallow draw situations and much later (about 50 per cent) during standard draw. Waste originates from above in most cases, while more significant portions often occur at about 20–45 per cent extraction.All the results from this extensive field test are not yet fully analysed, and further field tests are planned. A more detailed insight into gravity flow in large-scale SLC and possible influence by drilling, blasting and the mucking procedure is expected in the future.CITATION:Nordqvist, A and Wimmer, M, 2016. Holistic approach to study gravity flow at the Kiruna sublevel caving mine, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 401–414 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

An Integrated Solid Waste Management Method for Western Macedonia, Greece

Sep 13, 2010

GENERALTHE coal deposit, where it is being worked, consists of a bed of brown coal varying in thickness from 120 ft. to 200 ft., covered by an overburden of clay, drift, loam, etc., of a thickness of 22 ft. to 40 ft., and averaging 28 ft.The overburden is first entirely removed from the coal, and then the coal is excavated by. large revolving shovels which work at the bottom of the hole or open cut in the coal and deliver it in shovel bucketfuls to the transport system. The shovels owned by the Commission and available for this coal excavation are two Bucyrus steam revolving shovels, one being type 150B, weighing 150 tons, having a 21-cub. yd. bucket, and capable of digging a 47-ft. face; and the other being type 175B, weighing200 tons, having a 31-cub. yd. bucket, and capable of digging a 61-ft. face.In addition to these two steam shovels, the Commission has recently obtained a No. 250 Ruston electric revolving shovel weighing 340 tons, and having a bucket of 10 cub. yd. capacity, and capable of digging a 75-ft. face. When this electric shovel has been erected it will replace the steam shovels on the coal excavation, and the permanent transport system has been designed to take delivery of the coal from its bucket.The duty to be performed by the transport system is to take the coal from the shovels, elevate it out of the open cut, transport it to the screening house, deliver it iuto the hoppers at the top of this building, then to take the coal after it has passed over the screens and distribute the required grades to the power house and to the briquetting plant.

Jan 1, 1924

Studies of the Main Seam in the Rapahoe Sector of Greymouth Coalfield have shown that the proportions of palynomorphs and palynomorph groups vary vertically within the seam, but remain laterally consistent. Subsequent examinations of other seams in the Rapahoe Sector have demonstrated that the changes in palynomorph proportions observed in the Main Seam are specific to that seam, effectively providing a seam 'fingerprint'. Such a characteristic signature may be used to identify the Main Seam where faulting or seam splitting confuses seam correlation between drillhole intersections. Palynomorph assemblages are derived from the original plants which formed the peat mire, and yield information on mire conditions such as climate, mineral matter input and chemistry. These depositional factors influence coal properties such as mineral content, volatile matter yields and coal breakability. Palynological data can therefore assist in development of depositional lTIodels for prediction of coal quality variations. Several other, thiner seams in the Rapahoe Sector have been demonstrated to also contain recognisable palynomorph assemblages, suggesting that other seams may also possess distinct palynomorph abundance profiles.

Jan 1, 1996

Significance of Ion Interactions in Flotation in Saline and Brine Solutions

Sep 13, 2010

Electricity will play a major part in providing energy services in the 21st century. Ecologically Sustainable Development (ESD), that is accommodating the needs of the present without compromising the needs of future generations, will provide a focus for optimising the use of electrical energy. Environmental externalities may redefine the cost structure of electricity. Strong corporate environmental management will ensure that current environmental objectives are met and that future ones, identified by the ESD process and environmental externalities accounting, can be developed and implemented by receptive business managers. This paper addresses the current environmental issues of electricity production. It outlines a management strategy for the SECV becoming a community leader in protecting the environment. ESD is discussed in terms of using non-renewable resources wisely, extending their availability and putting in place mechanisms which ensure their ultimate substitution by renewable resources and conservation. The paper explores options for dealing with costing environmental externalities, particularly in relation to greenhouse emissions.

Jan 1, 1992

By Madsen I. C, Langberg D. E

Recent advances in X-ray diffraction (XRD) technology have made it possible to conduct powder XRD measurements on samples at high temperatures during reaction. State-of-the-art detectors are now capable of rapidly acquiring diffraction patterns across a wide angular range (typically 120"20) enabling phase transformation rates to be measured directly during sample reaction. In this study, the phase transformations during the reduction of hematite to metallic iron by five per cent hydro ºen in nitrogen gas mixtures, were measured in situ between 500 - 700 C. Complete X-ray diffraction patterns were acquired within 15 seconds every one minute, enabling direct measurement of the transient phase abundances during the reaction. The data were quantitatively analysed by the Rietveld method to yield the abundances of hematite, magnetite, wustite and metallic iron, as functions of time during the reduction process. A first-order reactions-in-series model was proposed, and the reaction rate constants and activation energy were determined from the time-dependent phase abundance data.

Jan 1, 1999

By Johnson N. W

After an unsuccessful transfer from the laboratory to the pilot plant of galena flotation technology which used sodium metabisulphite and ethyl xanthate, laboratory flotation tests were conducted to identify any unusual variables which had a deleterious effect on the position of the lead rougher grade recovery curve for Hilton and Mount Isa silver-lead-zinc ores. Two variables (pulp temperature and contact time for ethyl xanthate and sodium metabisulphite) had important deleterious effects.The findings allowed a successful transfer of the laboratory process to a pilot plant scale process. The effect of temperature was important because the higher temperature (40°C) in the pilot plant pulp increased significantly the rate of reaction between ethyl xanthate and sodium metabisulphite. In the laboratory process at 20 to 25°C, the reaction rate was lower and did not interfere significantly with the process. The contact time for the two reagents was also important in the pilot plant scale process because of the higher reaction rate at 40°C.To employ ethyl xanthate in the pilot plant process, special precautions were required. Further, a collector (Aerofloat 241) from the dithiophosphate family was used successfully in the pilot plant process.

Jan 1, 1988

Factors leading to the necessity for some individual testwork in solving most specific hydraulic transportation problems are listed and a description is given of a method used in determining critical flow conditions. An outline is given of the basic theory of the purpose of the testwork, and a means of applying test results for varied pipeline diamet.er and material conditions follows. Engineering and economic factors are applied to the solution of a specific hydraulic transportation problem and the use of the test results in plant practice is illustrated. The advantages of connecting pumps in series in centralised pumping stations rather than individually along the pipeline are stressed. Some notes are added on the future possibilities and economies of post pump injection of solids into high pressure pipelines.THE HYDRAULIC TRANSPORTATION OF SANDSAs well as all the classical variables involved in a pipeline installation, one must consider, when solids are to be transported, the effects of such variables as:(i) Proportion of solids in the pulp.(ii) The average specific gravity of the pulp.(iii) Specific gravity of the solid material.(iv) Solid particle average sizing and possibly shape.(v) Solids particle grading.(vi) Pipeline diameter for effects other than classically hydraulic.(vii) Pipeline material.(viii) Fluid viscosity.(ix) Pump characteristics.(x) Abrasive or corrosive properties of the pulp.Not surprisingly, the application of published data to the hydraulic transportation of a specific material is difficult if not well nigh impossible. Most hydraulic transportation investigations also involve economic and site factors vary...

Jan 1, 1959

By R B. Stewart

Where pasture production is the intended land use of the areas to be reclaimed, the creation of a suitable growing +medium is a major objective. To achieve this land reclaimers require a sound understanding of the proposed mining plan and a knowledge of the physical, biological and chemical properties of materials intended for resurfacing disturbed areas. Where the original soil is not being replaced in its natural state, research is usually required to determine an alternative growing medium. Results from field research conducted on waste material from the Waihi Gold mine are reported with emphasis on the significance of soil depth in relation to pasture production in this environment.  Problems in extrapolating field research to large scale operations are also considered.   Essentially the requirements for successful pasture production, on surrogate growing medium, are akin to conventional approaches used in New Zealand in the development of unimproved agricultural land. High inputs of fertiliser are initially needed, especially where volcanic soil is used, and careful management of pastures and soils is required to minimise soil erosion and create a sustainable system. In the first three to five years of pasture production, grazing use of the land requires to be dictated by pasture availability and soil conditions and not by animal feed requirements. The use of light stock (young dairy or sheep) is recommended.   Successful land restoration requires a team approach by a range of cooperative specialists including engineers, soil scientists, farm managers, agricultural contractors, landscape architects and environmental officers.

Jan 1, 1991

The cost of preparing a feasibility study is notoriously difficult to estimate. Studies for mining projects are typically commenced when an exploration programme has identified a mineable resource and pre-feasibility studies have shown that development of the resource would lead to an economically viable project. Pre-feasibility studies will normally include an estimate of the cost of a formal feasibility study and this estimate would then be firmed up before a commitment is made to proceed with the formal study. Data for preparing the feasibility study cost estimate will be sketchy, geological investigations, metallurgical testwork, and marketing studies may be needed before the scope of the project and hence the scope of the formal study can be finally determined. Before an estimate of the work required and hence of the cost of the feasibility study can be prepared the source of project funds must be decided. Studies for internally funded projects are often less rigorous than those which must be "bankable" and subject to the scrutiny of external financial institutions. This paper sets out suggestions for preparing more accurate cost estimates for feasibility studies by ensuring that all activities are included and shows how a staged approach to preparing such studies can minimise costs and guard against cost overruns. It also provides a case study showing how the estimate compared with actual costs for a recent feasibility study completed by Pancontinental Mining Limited.

Jan 1, 1990

By E N. Sajin

The final arsenic bearing waste products at the majority of metallurgical and chemical enterprises are cakes in which arsenic is present in the form of calcium arsenate. Burial of cakes demands construction of special burial sites and does not guarantee reliable protection from arsenic penetration into the ground and surface waters. Under laboratory conditions we developed technology for processing calcium arsenate cakes with obtaining low toxic products suitable for long-term storage, meeting environmental requirements. The investigations have shown that thermal processing of briquetted mixtures of cakes containing 15 - 20 per cent weight of pyrite under the temperature of 873 - 923¦K during 45 - 60 minutes gives briquettes sufficiently hard for transportation and long-term storage. Arsenic, under high sulphidisation temperature is bonded into low solubility non-volatile iron sulphide bearing compounds having chemical properties similar to the natural arsenic compounds. Solubility of the obtained products in neutral, acid and alkaline media was investigated during long period of time (three to 12 months). It was determined that arsenic content in the solutions did not exceed the norms for cultural and welfare basins and fish-ponds.

Jan 1, 2002

By J Hall, A Gallardo, M Strizek

Mineralogy and coproponents Sino Iron, International Minerals and Austeel are in the process of developing four world class magnetite iron ore mines with multiple open pits along a 25 km strike length of Brockman Iron Formation to the south of Cape Preston on the West Pilbara coast. The close proximity of the proposed pits raises some challenging project approvals and environmental management issues relating to the impacts of dewatering at individual projects and the cumulative impacts of progressive development on local and regional groundwater resources, which includes a large fresh water aquifer system in the Fortescue River alluvium.This paper presents an outline of the hydro-environmental impact assessment process adopted and the key result that the cumulative impacts of dewatering at all four projects on the local brackish groundwater system in the basement rocks is only marginally more than the impact of any one project on its own, and that the impact on the Fortescue River alluvium aquifer is negligible. The paper also presents an outline of the proposed integrated water management approach that will involve coordinated monitoring, ongoing impact assessment and management, and reporting programs for all projects.

Jan 1, 2009

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

Project cost control procedures and computer systems have enjoyed a successful and simple relationship over the past decade, thanks primarily to the proliferation of portable computers or PC's. Prior to the introduction of this technology, project control was largely a manual and somewhat onerous task of historical data compilations, with little time available for dynamic forecasting, staged planning, or pre-emptive cost control. Automated systems developed during this era were resident on "Heavy Iron" or mainframe computers and were expensive to maintain and operate. Use of these early systems was limited to large engineering, construction, and industrial concerns with the economies of scale and funding required for their successful application. Systems were either designed for critical path analysis or task scheduling, but rarely integrated with the other, much less cost control.

Jan 1, 1990

By A Proudman, J Isles, R Lawolo, G Forster

PT Nusa Halmahera Minerals (PT NHM) is an Indonesian joint venture company owned by Newcrest Mining Limited (75 per cent) and PT Aneka Tambang (Persero) (25 per cent). PT NHM operates two underground gold mines, Kencana and Toguraci at the Gosowong mine site in North Halmahera District, North Maluku Province, Indonesia.Due to several major stope overbreak events at Toguraci, the mining method and sequence was reviewed. The method was changed from a bottom up Avoca stoping approach using waste rock as fill material and leaving sill pillars, to a top down open stope method using paste fill without sill pillars.The revised mine plan originally had stoping progressing from the current level to the base of reserves followed by extraction of the sill pillars in the upper levels at the end of mine life. Geotechnical modelling was conducted on the revised mine plan and it was recommended that the sill pillars be taken early due to the risk of them overstressing and being difficult to recover if left until the end of mine life. The backfill material above the sill pillars is unconsolidated run-of-mine development waste rock or unconsolidated rock fill (URF).Due to earlier attempts to extract sill pillars under URF not being successful in the upper areas of the mine, it was stipulated that the URF above the five remaining pillars must be consolidated prior to stoping. Cost benefit analysis showed this to be justifiable due to the high-grade nature of the ore locked up in the pillars.Grout was initially planned to be injected in one pass through self-drilling anchors (SDA) in a 2.5 m pattern. Initial attempts to do this failed due to the SDA aperture and grout consistency. A modified method was employed using poly pipe installed into open holes that were drilled through the sill pillar and into the URF from below. Repeated application at each location ensured full grout consolidation. Drill holes were used to confirm grout thickness as well as add more grout. Design thickness was based on stress analysis.Despite different URF types being present due to varying quantities of fines, the process was similar for each area. The presence of paste in the URF of one target affected the quantity of grout it received.With a design thickness of 4–5 m of consolidation in the URF, depending on stope width and dip, each consolidated pillar (to date) maintained integrity during the stope operation. Some fall of material was anticipated; however, quality assurance / quality control (QA/QC) during grouting, staged stope extraction and careful blast design minimised fall of material.CITATION:Proudman, A, Isles, J, Lawolo, R and Forster, G, 2017. Rock fill consolidation for the extraction of sill pillar stopes at Toguraci gold mine, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 199–210 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017