Search Documents

By E T. Baker, J A. Resing, S L. Walker, V Ferrini, F Martinez, R Haymon

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Enumerating active sea floor hydrothermal sites has been a challenge since their discovery almost 40 years ago. High-temperature hydrothermal sites are readily discoverable, primarily by detecting mineral-laden plumes, but working at these sites poses severe environmental and operational difficulties. Low-temperature vent fields, which may represent waning of venting from high-temperature systems, may be more accessible but are more difficult to locate. Over the last decade, however, oxidation-reduction potential (ORP; aka Eh) sensors capable of detecting minute concentrations of reduced hydrothermal chemicals have been successfully used to pinpoint such fields. In this extended abstract, we use ORP anomalies observed during continuous (towed sensor) plume surveys to estimate site frequency along four intermediate- to fast-spreading ridge sections. From these data, we estimate site frequencies between five and 16/100 km for these ridge sections. Previous camera surveys on the fast-spreading East Pacific Rise support these frequencies. These rates are much greater than the frequency of ~0.5–5/100 km, generally increasing with spreading rate, derived from well-surveyed ridge sections in the InterRidge database (InterRidge, 2014). The higher frequencies arise because ORP sensors are able to distinguish between sites as close as ~1 km and identify sites with negligible or no optical plume signal.CITATION:Baker, E T, Resing, J A, Martinez, F, Haymon, R, Walker, S L and Ferrini, V, 2015. How leaky are oceanic ridge axes? A new assessment of the spatial density of submarine hydrothermal discharge, in Proceedings PACRIM 2015 Congress, pp 3–8 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

The Pike River Coalfield is located on the West Coast of the South Island of New Zealand near the top of the Paparoa Range approximately 45 km north east of the coastal town of Greymouth. The Pike River Coal Company Ltd (PRCC) is owned jointly by New Zealand Oil & Gas Limited (NZOG) and private investors.   The project has followed a long and difficult road towards project implementation which is now a reality with mine construction scheduled to commence in November 2005. The first stage of the project, the consent and land access process has been the most difficult. Resource consents for the project were first applied for, granted and appealed in 1998. A second round of modified resources consents followed a similar path in 2001. Following consultation with a range of parties including local and central government as well as the Department of Conservation, in March 2004 the Minister of Conservation granted PRCC access through Department of Conservation land. In October 2004, the Environment Court issued a Memorandum of Consent granting resource consents with conditions that had been negotiated between PRCC and the appellants.   The second stage of the project, investigation and design, commenced in December 2004 and was completed in June 2005 with the PRCC board ratifying the project capital and operating budgets. While the investigation and design work was proceeding, PRCC were also engaged in securing private equity and bank debt funding for the project. Formal Board approval to proceed with project construction was granted in September 2005 following completion of fund raising.   The project consists of a number of significant construction activities, namely: +        10.5 km of mine access road through previous logged and virgin rain forest; +        2.2 km of tunnel through metamorphic rock; +        a coal preparation plant about 8.3 km from the mine portal; +        an underground coal preparation plant; and +        a major slurry pump station, high and low pressure underground water supply systems to support hydraulic mining units and underground coal transport respectively.   Project construction is expected to be completed in April 2007 with completion of the ventilation shaft. Mine production will commence in December 2006 with coal from pit bottom development which will be carried out by the mine owner.

Jan 1, 2005

By Clarke B. N

The Olympic mine is currently and development to 1988. The mine practice is, and number of factors. Dam copper-uranium-gold undergoing construction start production in May ventilation design and will be determined by a These include: 1. Mining method and degree of mechanization. 2. Presence of radon emanating material. 3. High virgin rock temperatures at relatively shallow depths. 4. High ambient air temperatures in Summer.

Jan 1, 1988

By B Cooper

During the design of a new production facility for a greenfields or significant brownfields expansion many design decisions are made driven by an unquestioning objective to achieve 'lowest cash-cost' production costs. In many cases this translates to a design and operating philosophy based on largest-available, single-line equipment. Although acknowledged as an approach that is efficient from an operating cost perspective does this approach always maximise shareholder value? There is an increasing awareness in the mining industry of the value of project flexibility, robustness and value options. The design of a new production facility creates a window of opportunity which should be structured to ensure that project value options and robustness are understood and exploited. This requires the use of emerging valuation methodologies, such as Value-at-Risk and Real Options, as well as tried and trusted NPV/IRR approaches. The paper provides an overview of the basis and application of these less well known techniques in the context of metallurgical plant design. Design guidelines that demonstrate how value options and flexibility can be quantified from both a risk and value perspective are presented. Issues such as use of single versus multiple line equipment, optimum cut-off grade and improved exploitation of the inherent variability of the orebody are also examined. Finally the management issues and approaches to achieving this will be briefly discussed; for example it is common during project development to drive towards increasing certainty as rapidly as possible to facilitate 'accurate' estimation of costs. Understanding and exploiting value options requires a project culture that tolerates, and revels in, ambiguity and uncertainty û something that would make many project teams uncomfortable!

Jan 1, 2008

By Richmond AJ, Allan J

The use of long-hole in-seam drilling techniques for seam gas drainage ahead of mining was introduced to the Australian coal industry by ACIRL in mid-1981. ACIRL's research program has involved the development and demonstration of drilling and borehole survey technology in addition to evaluating the gas drainage potential of long-hole in- seam boreholes. This paper presents the results of the long-hole drilling carried out to date in the Illawarra District of the New South Wales coal fields. Drilling experience in relation to both vertical and horizontal directional control of the drill string, drill performance and borehole survey techniques are discussed. In addition, results of gas drainage effected by the long boreholes are presented. Future potential and requirements for further development of this technology are Reviewed.

Jan 1, 1982

By R Polmear, G Mauger

You wouldnÆt start excavating before testing core samples, so why would you approve a project plan before all factors have been identified, reviewed and addressed? Even a champion sports team made up of the best players canÆt produce optimal results without a well understood and agreed game plan. Could an F1 racing team produce their outstanding performance without rigorous evaluation and testing of the factors for successful performance? Why would we expect a capital works project team to be able to get it right without an understanding and an involvement in setting and implementing the overall game plan and without an understanding of all stakeholder requirements? For International PowerÆs Hazelwood (IPRH) mine in Victoria, the challenge was development and delivery of a 40 year mine plan, ultimately involving relocation of existing mine operations into an adjacent new coal field, land acquisitions and major environmental and other approvals to allow diversion of three streams, a highway, an Over Dimension route and other infrastructure in a political and environmentally sensitive atmosphere. The lessons from International Power HazelwoodÆs (IPRH) experience are: that the clear set of project principles and guiding values ensured delivery of a robust plan; a robust plan can withstand significant change; and value management (VM) played an important role in providing assurance, to all, that the plan was sound at both the strategic and micro levels. This Hazelwood mine project included five major VM workshops. The first was a critical review process in addition to design and cost reviews. This VM workshop was used to analyse, at a high level, the preferred coal mining sequence and design concepts, together with the interaction between design elements, risks and costs. In addition to this, the workshop provided an agreed common pathway for all downstream decisions. A second VM study was conducted to ensure that the proposed plan and design for relocation of the conveying systems from the existing mine into the new field were planned for optimum achievement from a whole of life cost, time, operational and maintenance perspective, plus the logistics of continuing operations while relocating assets. A third study followed to review the Conveyor Transfer Alliance and review functional design. A fourth VM study workshop was formed at the start of Phase 2 Alliance to ensure that the best value for money was being achieved through the current design, schedule and project arrangements and that all interfaces between parties had been reviewed and responsibilities were clear and understood. Other studies are outlined later in this paper. This paper details the evaluation criteria and processes used in the project evaluation that led to the WestField Mine Development.

Jan 1, 2007

By H J. J Boshoff

Pit lakes, as a final void after completing open cut mining, are in most cases unavoidable. Initial mine designs and approvals require consideration and assessment of closure objectives, legislation and stakeholder acceptance to ensure suitable understanding of the closure liability. Mining companies undertake studies and engineering during the planning, operational and closure stages of mining to identify closure options for the final voids, which would be sustainable. Without adequate planning prior to and during the life of the mine, options during the closure stage become limited resulting in costly closure works or long-term liabilities. Engineering consultants provide a specialist service in the assessment of long-term pit lake water levels and characteristics. Ongoing advances in mining methodology and technology, coupled with improved data collection and data management aid in a better understanding of the complexities in estimating long-term pit lake water levels and characteristics. Closure objectives developed during the planning stage sets the requirements for long-term pit lake water levels, which could require maintaining a water level and pit water or discharge water quality. A variety of approaches could be used to assess these closure scenarios each requiring specific data and methodologies. Typically, limited data is available during the planning stage, which results in assumptions based on past experience and relevant case studies. Closure assessments are revisited during the life of mine and leading up to the closure stage, during which additional site-specific data is available improving the accuracy of the assessments.CITATION:Boshoff, H J J, 2018. Assessment of approaches, data requirements and methodologies for estimating long-term pit lake water levels, in Proceedings Life-of-Mine 2018, pp 28–31 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By H Höft

Today tunnel segment liners are sealed with corner-vulcanised gaskets made of extruded elastomeric compression profiles. The profile geometries and the elastomeric materials have been further developed in course of time to meet the steadily increasing water-proofing requirements. After 40 years of using such compression gaskets, a wide range of proven standard profile geometries and well-known brands can be found on the market. Even so, there is still potential for further developments and improvement, not only with regard to the water-proofing performance. Permanently increasing cost pressure in the segment production plants demands further developments and new solutions with regard to application techniques. This is an abstract only. No paper was prepared for this abstract.

Mar 8, 2011

By A Riles

"Three issues of relevance in a modern tailings storage facility (TSF) are:geotechnical stabilitymanaging acid rock drainage (ARD) from pyritic tailingsmanaging the tailings from cyanidation of gold ores. Drawing on examples from both copper porphyry flotation and sulfide-hosted gold ores, this paper demonstrates that giving some weight and importance to the process tails properties upfront can influence the flow sheet and not only improve tailings management effectiveness but also impact positively on economics. In the case of a typical copper porphyry ore with moderate pyrite content, the rougher tail in a conventional high pH selective flotation step is usually classified as potentially acid generating (PAG). To avoid the generation of ARD within the tailings and the requirement for a costly plastic lining, subaqueous deposition is recommended, which in turn has negative implications for tailings stability, consolidation and closure. Adopting a neutral pH rougher stage rejects silicate gangue but recovers pyritic material to the cleaners for a subsequent selective flotation stage, often after regrinding. This effectively quarantines the PAG pyritic material in a much lower volume cleaner tail, which can then be appropriately encapsulated within a larger non-lined flotation tails facility. It also facilitates cyanide leaching of the cleaner tail for gold recovery, with the encapsulated tailings facility being suitable for cyanidation tails storage. A case study from Europe is examined. For gold ores where the gold is sulfide-hosted, but not refractory, a flotation route with cyanidation of the concentrate can similarly produce the majority of tailings as a benign flotation tail and again quarantine the low volume concentrate leach tail in a small encapsulated cell with appropriate residual cyanide management measures applied. Overall economics for intensive leaching of a low volume concentrate stream can also be surprisingly positive. A feasibility study design example of the process and TSF is presented. CITATION: Riles, A, 2016. An Integrated Approach to Optimising All Concentrator Products, Including Tailings, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 341–346 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By L Richards, R L. Brathwaite, C Mazenga

Underground mining of gold-silver bearing quartz lodes was carried out in the great mines at Martha Hill, Waihi over 70 years from 1882 until 1952. Shafts and stopes reached a total depth of 600 m on 16 levels, with workings extending laterally some 1.6 km, and as new reefs were discovered the workings extended beneath parts of the township. Over their long life the mines produced 1217 tonnes of gold-silver bullion from processing 12.2 million tonnes of mined ore. In the early-1980s drilling proved large reserves of gold and silver ore remaining in stock-work zones between the previously mined lodes. This led to a new era of mining at Waihi with the opening of the Martha Hill open pit in 1988. A series of three sink holes have formed above unfilled stopes of the Royal lode. In 1999 a sudden collapse crater 40 m in diameter occurred near an occupied part of Waihi, placing in danger several houses and a busy street. This crater formed close to a similar crater that occurred in 1961. The 1999 collapse resulted in subsurface investigations and risk assessment studies being commissioned by the local Hauraki District Council. However, a further 50 m diameter collapse crater in December 2001 formed in a residential area, swallowing and wrecking an occupied house, fortunately without injuring its five occupants. Two other houses were perched on the crater rim. The 2001 collapse led to an acceleration of the work being carried out by the Institute of Geological and Nuclear Sciences Ltd. (GNS) to identify the extent of the old underground workings at Waihi. For the risk assessment detailed rock mechanics analyses were made to consider the stability of the underground mine stopes, in terms of the stope back, hangingwall, footwall and crown pillar failure mechanisms, as well as void migration. The collapse crater areas were analysed using using several methods, including analysis to simulate the probability of void migration from unfilled stopes to the surface using the @Risk program. The analyses show that in the cases of the actual collapse craters, the voids have a high probability of migrating to the surface, thus providing a method of testing the void migration modelling. Modelling analysis applied to the remaining stopes of the old underground mines show there are further areas where void migration from unfilled stopes has a high, medium and low probability of reaching the surface as a collapse crater. The locations of these probabilistic hazard zones were outlined using the @Risk modelling and deterministically by using the dimensions of the historical collapses applied along the length of the stopes. Consideration of the æincubation periodÆ (the time interval between the cessation of mining and the occurrence of collapse) and comparisons with mine subsidence histories overseas, indicates that further collapses are likely to occur over the next 50 years. Risk assessment estimates made using property values and occupancy levels within the three hazard zones, were compared with Societal and Individual Risk criteria. Results indicate that safety within the high and medium zones may be unacceptable.

Jan 1, 2003

By J-P Franzidis

A technique for determining the recovery of attached particles across the froth phase in flotation that relies on measuring the rate at which bubble-particle aggregates enter the froth is used to investigate the selectivity of attached particles across the froth phase. Combining these measurements with those of other techniques for determining the froth recovery of attached particles provides an insight into the different subprocesses of particle rejection in the froth phase. The results of experiments conducted in a 3 m3 Outokumpu tank cell show that the detachment of particles from aggregates in the froth phase occurs largely at the pulp-froth interface. In particular it is shown that the pulp-froth interface selectively detaches particles from aggregates according to their physical attributes.

Jan 1, 2005

By J Parmenter

Issues around water û its quality, use, availability and environmental value û can be a major point of tension between mineral projects and local communities. Failure to manage these issues appropriately can jeopardise the obtaining of regulatory approvals for new projects and place at risk the æsocial licence to operateÆ of existing operations. Conversely, there may also be significant opportunities for companies to engage constructively with communities over water issues and to make a positive contribution to the sustainable development of these communities. Using case studies, this paper will explore the various types of social risks and opportunities associated with water and mineral resource development and identify key learnings relating to the management of these issues.

Jan 1, 2006

By J Krahn

In designing climate exposed soil structures such as caps and covers over mine waste it is necessary to include the wetting and drying influences of the local climate in order to accurately predict the net water, vapour and oxygen fluxes across the ground surface and through the base of the covers. The most advanced evaporative flux modelling tools currently available to practitioners have been limited to rigorous one-dimensional models (ie SoilCover) or semi-empirical two-dimensional models (ie Hydrus-2D). It is common practice to use the rigorous one-dimensional evaporative flux model results to develop a surface boundary function that can then be applied within a saturated/unsaturated two-dimensional model. However, this is not an ideal situation and results in a further approximation of the real system being modelled. This paper will highlight the use of a new modelling tool, VADOSE/W, which brings existing, rigorously formulated evaporative flux theory into the familiar setting of a two-dimensional model. The model is enhanced for simultaneous two-dimensional oxygen gas transport analysis, which has direct application in the mine waste industry. A key focus of the paper will be addressing the limitations of one-dimensional analysis for cover systems on sloping and hummocky terrain.

Jan 1, 2003

By I Doye

Acid mine drainage is a serious environmental problem caused by the oxidation of sulfide minerals responsible for highly acidic, sulfate and metals-rich drainage. Several methods of mine waste management have been developed that reduce liabilities on environment. Layered co-mingling of waste rock with compacted tailings, covers with capillary barriers effect, and co-disposal of waste rock and tailings are these new methods which are used to reduce the formation of acid mine drainage. These methods shield waste rock dumps from oxygen. These techniques could prevent oxidation reaction. In this study, alkaline industrial wastes are used with acid generating tailings to inhibit acid mine drainage. The alkaline wastes selected are cement kiln dust (CKD) and red mud bauxite (RMB). These alkaline materials are used to keep neutral conditions in the fine material layer and to inhibit the metabolic activity of Thiobacillus ferroxidans which catalyses the oxidation of sulfide minerals. A series of timed static leaching tests were performed by reacting samples of mine tailings with two, five and ten per cent alkaline material in order to characterise geochemical balance between liquid and solid phases. Column tests have been set up with oxidised tailings, waste rock, CKD, and RMB. Column tests have been carried out to simulate layered co-mingling, covers, liners, and co-disposal of waste rock and tailings. Column leach tests were conducted in order to investigate the long-term neutralisation potential of alkaline materials and the drainage water quality. Bacteria counting were performed on each sample after testing. The results obtained show that the addition of alkaline materials permit the retention of near neutral conditions in the fine material layer, thus increasing water quality and preventing bacteria development. In fact, the pH results show that the use of five per cent, ten per cent CKD or ten per cent of a mixture of CKD and RMB permit the retention of neutral pH conditions in the reactive layer. At these percent rates, the concentrations of Al, Fe, Cu, Zn, and SO4 in solution are significantly reduced compared to those obtained with the tailings only. In presence of waste rock, the relative position of the fine material layer is important. When the fine material layer overlaying reactive waste rock is composted of reactive tailings with ten per cent CKD and ten per cent (CKD:RMB), a delay was observed before achievement of near neutral pH. The neutral pH conditions remain stable over time. The mixture of CKD and RMB provides a better short-term neutralisation than the use of CKD alone. The use of alkaline materials is beneficial in order to reduce the concentrations of Fe and other metals such as Cu and Zn as well as the number of viable bacteria. The use of ten per cent RMB alone does not involve the neutralisation of reactive tailings. In the cases where the fine-grained layer are below or mixed with the waste rocks, the near neutral pH values are directly reached with ten per cent CKD. However, the pH values decrease rapidly and the number of viable bacteria increases.

Jan 1, 2003

By G Diprose

Diamond exploration in Queensland is influenced by the South African approach modified by the discovery of diamonds in Lamproite in Western Australia. The current approach is to explore for Kimberlite and Lamproite bodies using indicator minerals dispersed by fluvial and colluvial processes. In the north-west, diamonds are derived from kimberlitic and lamproitic sources, whereas those in the coastal and subcoastal areas of eastern Queensland are associated with xenoliths included in rocks formed during Cainozoic volcanism. In these areas, sapphire is commonly associated with diamonds. In New South Wales diamonds in economic quantities occur in alkali basaltic intrusions and a subduction model has been proposed for these occurrences (Barrows et al, 1996). Exploration for diamonds in Australia increased following the discovery and exploitation of the Argyle mine. State geological surveys have produced digital information on the local occurrences of diamonds. As part of the Smart Mining Initiative (2006 - 2010), the Geological Survey of Queensland compiled a database and report on microdiamonds and diamond indicator minerals from open file company exploration data from 1968 to 2008 from the Department of Mines and EnergyÆs QDEX system. Most exploration in Queensland was conducted with exploration for other commodities. There is no commercial exploitation of diamonds in Queensland and, to date, only rare occurrences of microdiamonds. There is a regional difference in diamond occurrences with the kimberlitic and lamproitic models favoured for the north-western regions of the State and the subduction (S-type model) favoured for the eastern coastal zone linked to Cainozoic alkalic basaltic volcanism. Further diamond exploration is warranted in Cainozoic basalt provinces along the eastern coastal and near coastal regions and in the north-west of the state in conjunction with airborne geophysics flown as part of current Departmental Smart initiatives. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

Since the days of Adam Smith and Milton Friedman the discussion of corporate citizenship and sustainability has been flooded with multiple contradictions, with proponents of sustainability saying that it is a crucial cog in the business strategy, while those against, maintain that æthe business of business is businessÆ and therefore sustainability issues are just add-ons. Sustainability arises from a deeply held vision by corporate leaders that businesses can and should play a role beyond just making money. Businesses should embrace the understanding that everything that a company does has an impact both internally and externally (communities, employees and customers), and the natural environment. This paper highlights the approach that led to a view that there is a contradiction between profitability, sustainability and community development, and we provide a further argument to the contrary. This argument is based on a comprehensive literature review of over three decades by various scholars linking corporate social performance and corporate financial performance. Driefontein Gold MineÆs approach is that of linking the community development, natural environmental and employee well-being initiatives and projects to the mineÆs business strategy. The paper further highlights the coordination and implementation mechanism of sustainability at the mine where the accountability lies with the head of the mine operations. A two pronged approach is employed where there is an internal dialogue on sustainability between the various departments coordinated by the sustainable development department and an external tri-sector partnership with local government, interested and affected parties and the mine. These approaches are closely linked to the contributions towards the mineÆs financial bottom line.

Jan 1, 2009

Intermontane valleys form unusual features of compressive mountain belts both in the sharp topographic break they represent and in the strike-slip displacements often associated with the valleys. Such strike-slip motion seems hard to reconcile in the actively deforming Andes where reconstructions have indicated nearly perpendicular Cenozoic plate convergence. Detailed study of a part of the Argentine Andes between latitude 31-33¦S suggests that, although strike-slip displacements may have largely created a prominent intermontane valley system, no Holocene strike-slip displacements are observed amid the relatively active compressional deformation along the mountain belt flanks. New plate reconstructions, treating the Nazca plate as two microplates separated by fractures along the Nazca Ridge, predict large components of strike-slip motion between the South American and Nazca Plates for the period from 10 to 5 Ma. These reconstructed plate motions are consistent with strains derived from recent kinematic analyses of minor faults along the southeast margin of the Puna plateau and the general timing of tectonic phases in the Andes.

Jan 1, 1987

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

By A Keddie

Standard microeconomic theory suggests that the behaviour of mineral extraction and processing firms with respect to their demand for water can be modelled and a market demand for water subsequently derived. Such a model, although an abstraction of the real world, should be able to predict the responsiveness of quantity of water demanded to change in price, and, change in demand to a range of factors including: expectations about reliability of supply, changed commodity prices for mineral production, and change in water technology and storage at mine site. This paper demonstrates that the price of water is particularly responsive to changes in demand and that although price increases would result in some additional supplies, physical constraints on supply suggest that the industry will be paying considerably higher prices for water in the future. It is recommended that the mining industry undertakes quantification of possible price increases to position itself to minimise the impact on their operating costs as well as to make responsible capital investment decisions to facilitate future expansion or commissioning of new mines. Substantial investment is required to commission a new mining venture with expected rates of return subject to risk and uncertainty due to fluctuations in world commodity markets as well as reliability of secure supplies of inputs. If a reliable supply of water was subject to uncertainty and water was a critical input for production, then the initial mine design would typically consider a range of production decisions contingent on levels of uncertainty with respect to water supply. These states or sets of water supply, will affect production decisions and future water demand. Modelling production decisions contingent on different states of nature, termed the state-contingent approach, provides a number of insights about producer behaviour under uncertainty. This paper investigates the assumptions underlying the derivation of the market demand for water by the mineral resource industry and identifies the drivers of demand and the responsiveness of the industry to change in price and supply, particularly in relation to capital investment in water-use technologies. The usefulness of these models to the mining industry is considered by reference to the increasing demand for water by the industry in Queensland, in a climate of water shortages.

Jan 1, 2006

By A Lechner, T Baumgartl, S Arnold, P Audet

When revegetation is a part of a rehabilitation strategy at mine sites in arid and semi-arid environments, its success can be strongly affected by the availability of water prior or during the time of seed dormancy, germination and early growth of seedlings. The semi-arid and arid environments of northern Australia are characterised by highly variable and erratic rainfall and hence the actual weather conditions at and around the time of germination and seedling emergence play a critical role in determining the success of plant establishment and the type of plant community that may develop.Using available climate data, an analysis has been undertaken and a set of indices has been developed which describe the suitability of the climatic conditions for rehabilitation. In total, eight sites from Queensland and one site from New South Wales, Australia have been analysed. It could be determined that regular rainfall and relatively short periods of water-deficit are key characteristics of climate suitability. A comparison of the locations studied allowed the separation into suitable and susceptible locations in terms of the availability of water, amount of rain and duration of drought between rain events.In our experience, specific estimates of climate suitability are rarely incorporated into the design of mined land rehabilitation programs. We consider that the regional intensity, seasonality and extremity of climate represent an overarching component of landscape complexity, which in turn will influence the development of post-disturbance ecosystems in these regions. This paper presents the outcome of climate analyses paired with the development of suitability indices. A conceptual framework is presented explaining the suitability matrix and its incorporation as a prognosis tool to achieve greater certainty for success in rehabilitation development.CITATION:Baumgartl, T, Arnold, S, Audet, P and Lechner, A, 2014. Development of climate-based suitability indices for the improvement of success in rehabilitation, in Proceedings Life-of-Mine 2014 , pp 483–490 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014