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By T Mizuta, H Satoh, M Ogasawara, M Miyata, M Fukuyama

The Miocene Chichibu granitoids associated with the Chichibu skarn deposit are divided into North Body, South Body and Daikoku altered stock. Orebodies of the Chichibu skarn deposit are mainly distributed in the north-western part of the North Body and Daikoku altered stock. The North Body consists of magnetite-series granitoids ranging from tonalite to granodiorite and to monzogranite from the margins to the centre of the intrusion. The South Body consists of tonalite and granodiorite, and most of these rocks are also classified as magnetite-series granitoids. The Daikoku altered stock consists of a quartz diorite porphyry. The SiO2 contents of the granitic rocks of the North Body and South Body range from 61.6 to 70.7 wt per cent. During magmatic differentiation, Cu, As and Zn contents in fresh granitic rocks of the North Body and South Body increase with SiO2 content up to 63 wt per cent SiO2, and then progressively decrease with increasing SiO2 contents as SiO2 exceeds 65 wt per cent. Estimated pressure for the emplacement of the granitoids is about 0.5 kbars. Cathodoluminescence studies on quartz from those granitic rocks show that vapour rich two-phase fluid inclusions tend to occur in the core of quartz crystals, while halite-bearing poly-phase fluid inclusions occur in the margins of quartz crystals. The distribution of fluid inclusions suggests that fluid composition changed from low to high salinities during the growth of magmatic quartz crystals. Texture showing quartz crystals with an oval shape enclosed by radial aggregates of a mixture of fine-grained quartz, plagioclase and K-feldspar composing the groundmass of the monzogranite also suggests a pressure decrease during solidification of North Body. These findings show that high salinity fluids were present during magmatic differentiation and that Fe-Cu-Pb-Zn-Au-Ag skarn mineralisation of the Chichibu deposit was possibly associated with these high salinity fluids. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

Stringent environmental benchmarks imposed by governments and successful legal challenges in the country of origin have changed the risk profile for all mining companies over recent years. In developing countries, however, where high government standards may not always be in place, direct community action has often made worthless substantial investments in otherwise viable mining operations. Real limitations are therefore imposed from these risks on all areas of mining activity, wherever they may be. Thus, the bar has been raised for all companies developing or operating mines. This paper argues real financial and global industry reputation benefits accrue when all known environmental risks, where practical, are managed. In response, among major international mining companies, as the industry moves towards greater global consolidation, senior management teams have increasingly adopted corporate governance standards including æTriple Bottom LineÆ (shareholder/government/community) sustainability reporting. Sustainability reporting is encouraged by improved international stockholder and financial investor perceptions by contributing to lowered social, community and geopolitical risk which lowers the cost of access to funds as well as improving staff morale and productivity. New mines must not only be primarily financially viable but must operate throughout in a sustainable way. Case studies of some recent mining operations, who have not foreseen or proactively managed major environmental risks, demonstrate the dire financial and personal implications for managers, directors and shareholders from not identifying and managing these environmental risks. Merely having a corporate policy statement on environmental standards or high level Government approvals process for a mining activity does not preclude mining operations from the risk of direct action by local populations or future adverse legal implications from risks which were perhaps identified but not mitigated effectively. Methods and processes for the identification and active management of environmental risks in the global arena are discussed to add a practical element to sustainability, based on the authors recent strategy development processes with governments and major mining houses such as BHPBillition, Rio and Xstrata. Emphasis is placed on proactive, innovative yet practical solutions which, where possible, show positive contributions firstly to the financial bottom line but also the community at large.

Jan 1, 2003

The Bureau of Mines, with a history of mining research since 1910, still seeks improvement in safety and health along with improvement and competitiveness in the mining industry. Much promise of such improvements lies in new technology, and this is particularly the case in the still growing coal mine sector, although much Bureau research is long term, high risk, aimed at new concepts.The miner's environment is a primary concern, involving technologies of contaminant monitoring and control in high production scenarios. Contaminants arising from diesel use, alternatives to high speed rotary cutting and more efficient dust removal are being addressed, and drilling efficiencies, better monitoring through unitising operations and insitu rock dust monitoring are particular features.

Jan 1, 1991

By Seib W

In cut-and-break rock excavation use is made of the fact that breaking rock in tension towards a free face requires a specific energy of excavation which is small in comparison with that required for rock excavation using conventional tools operating by a process of indentation of the rock.The process of cut-and-break excavation comprises firstly a cutting step in which a groove is cut into the rock surface, followed by a breaking phase in which a tool is inserted into the cut in order to break the rock adjacent to the cut.

Jan 1, 1992

By Cooper W. C, Stokes M. A

Proterozoic gold deposits in the Pine Creek Geosyncline are at present receiving renewed attention with the opening of old mines and several new discoveries. This important polymetallic province contains occurrences of gold, base metals, tin, tungsten, tantalum, platinum, palladium and aluminium. These resources have been exploited over the past century with periods of major interest during the turn of the century and during the past 20 years. Economically viable resources of predominantly gold, eg Pine Creek, Woolwonga, Brocks Creek and Union Reefs, and Ag-Pb-Zn, eg Woodcutters are currently in development or being mined. A variety of genetic models, ranging from magmatic through hydrothermal to syngenetic, have been postulated in the past for the formation of gold deposits in the Pine Creek Geosyncline. The first discussion on the regional geological factors that control ore deposition in the Brocks Creek-Howley District was by Sullivan and Iten (1952). They recognised that the most important ore deposits are associated with anticlinal and domal structures and that granites may be a controlling factor in the localisation of the mineralisation. More recently a group of authors, Needham and Roarty (1980), Goulevitch (1980), Nicholson and Eupene (1984), Sanger-Von Oepen, Friedrich and Kater, (1988), Nicholson and Eupene (1990) and Kruse, Whitehead and Mulder (1990) have suggested an exhalitive syngenetic origin, or remobilised syngenetic during dolerite intrusion and/or regional deformation, for gold mineralisation, especially those associated with South Alligator Group lithologies (eg Bridge Creek, Mt Bonnie group of mines and Cosmopolitan Howley). Studies carried out at the Bridge Creek and Western Arm Prospects over the last three years suggest that syngenetic models for gold mineralisation are less relevant to gold mineralisation in the Howley District than first thought (Wall, 1989; Partington, 1990). The Bridge Creek prospect has been cited as an example of a syngenetic-syngenetic remobilised deposit (Oepen, Friedrich and Kater, 1988) while the Western Arm prospect is more clearly a vein hosted epigenetic deposit and a comparison of the styles of mineralisation at both prospects will be made. The nature of the gold mineralisation at both prospects will be described and compared, and possible genetic models for gold mineralisation and their relevance to regional exploration discussed.

Jan 1, 1994

Instantaneous outbursts have occurred at Metropolitan Colliery from the pick and shovel work of early days to the modern mining techniques of today. Developments have been the introduction of an emission index to measure the proneness of the coal to outbursts, drainage and destressing by large diameter holes, attempts at higher productivity by the introduction of pulsed infusion shotfiring and improvements in ventilation. The future plans and aims for the Colliery include prediction of outbursts, seam gas pre- drainage and longwall mining.

Jan 1, 1980

By Davis A, Song J

A review of the literature indicated that several studies have been reported on the dissolution of gold using iodide/iodine, bromide/bromine leaching systems. Although the reagent costs are much cheaper for chloride/chlorine (or hypochlorite) this system has not been fully evaluated. This study was conducted to evaluate the fundamental chemistry of the chloride/hypochlorite leaching system. The CHEMIX program was used to model the stability of various gold species existing in the solution. The gold dissolution rate at different conditions was determined using gold strips immersed in various mixtures of chloride/hypochlorite. Leaching experiments were conducted to test the extraction of gold from various ores (oxidised and copper-gold ores), showing a promising prospect for this technique in various applications.

Jan 1, 1992

By D Chalmers

"There is a tendency to treat mine roadways with fan installations as leak proof systems. Morecomplex ventilation arrangements are being installed in coal mines out of necessity or designand these can introduce additional hazards. This paper explores the leakage paths that can existaround fans and in particular the hazards these leakage paths may generate around undergroundfan installations. The behaviour or these leakage paths in the event of a fan failure has also beenexplored. Early detection of spontaneous combustion is essential, so understanding the leakage behaviour around fans especially boosters or main fans installed underground will assist in sett ing up monitoring locations in the correct places. If this behaviour is not fully understood then monitoring may be placed incorrectly, or trends may not be picked up until it is too late."

Jun 1, 2012

I must tell you at the outset that I come to this conference deeply disturbed at the `role of Government in international dealings in mineral and energy resources'. I am disturbed by the confusion that now passes for policy. I am disturbed by the short- range view of critical problems taken by a majority of Governments. I am equally disturbed by the even shorter range of view taken by a growing army of industries. Many of them clamour for Governments to solve their problems in a specific way, with little regard for any other sector but their own-and with even less regard for the fact that every time a Government takes over some of their responsibilities they surrender some of their freedom. I would not say that longer range views don't exist. But I would say that they don't prevail at the present time. Instead, we are seeing the con- stant development of many policies for individual problems which don't tackle the fundamental causes. We must get back to basics without delay.

Jan 1, 1978

Kinetics of bubble-particle interaction, surface hydrophobicity and interfacial phenomena in sulfide mineral flotation are discussed in this paper. Results of the measurements of a bubble and mineral induction time (IT) and detachment force (DF), vacuum of bubble evolution (VE) and mineral floatability are discussed for pyrite, galena, chalcocite and chalcopyrite. Natural wetting and wetting induced by xanthates with different lengths of alkyl chains are examined. Experiments show the existence of several maxima of hydrophobicity on dependences of pH and electrochemical potential. These maxima are attributed as the reflection of mineral surface heterogeneity due to xanthate adsorption and the presence of cationic and anionic centres with uncompensated positive and negative charges. These charges can be neutralised by both regulation pH and applied potential. The aim of this paper is to evaluate a thickness of the rupturing film and to estimate how long the bubble-mineral interactions are according to the experimental values of IT, in order to develop a procedure for comparing of the results of DF and atomic force measurements in the same dimensionality, and to compare the results of the experimental studies on the wettability of sulfides with those predicted by the models of physics of capillarity.

Jan 1, 2005

By M Grigorescu, J H. Hodgkinson, M Khanal

The mining industry often needs to operate in remote or climatically harsh locations. The industry has recently been forced to deal with extreme conditions including floods, heatwaves and droughts. As these are becoming progressively frequent occurrences, mines typically build ‘downtime’ into production schedules and expect to incur costs to manage the various risks arising from climate extremes. Importantly, many environmental conditions are becoming more extreme and consequently, risk management based on past data can become increasingly ineffective. Market and shareholder demand for fewer interruptions are another pressure on mines to avoid prolonged or frequent downtime. Hence, adaptation to climate is becoming an important strategic move for many companies, many of whom are using future climate scenarios and alternative risk evaluations.We present here a method that uses commonly available mine site data to assist decision-making for reducing vulnerability to sudden flood. The method, ‘climate-related adaptation from terrain evaluation results’ (CRATER), identifies a mine’s flood ‘hot-spots’ and presents them as a ‘traffic lights’ warning map. The process then requires a failure analysis process such as fault-tree analysis to identify both the cause of possible failures and a range of possible failure-avoidance adaptations. In the final stage, management can assess the most suitable option for the mine, based on the availability of capital such as time, facilities, labour and money in addition to social acceptability of the options. CRATER has been tested in an open cut mine environment and is now being further developed to identify how subsidence over underground mines may impact on flooding and ponding over the mining life cycle (CRATER II). Further work is continuing to test larger and more complex mine landscapes to deliver a method to extract more knowledge from existing data.CITATION:Hodgkinson, J H, Grigorescu, M and Khanal, M, 2016. Reducing mine site extreme rainfall vulnerability using climate-related adaptation from terrain evaluation results, in Proceedings International Mine Management Conference, pp 187-200 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 22, 2016

By Hayes P. C

The kinetics of reduction of PbO-silicate melts in CO-N gas mixtures at 900¦C have been studied. Rea~tion rates were measured by moni- toring the CO2 content of the product gas. A wide range of gas and melt compositions and gas flowrates have been investigated. The overall reaction rates in heterogen- eous systems are typically characterised by a steady increase as the gas flowrate is in- creased. At low flowrates the processes are limited by gas film mass transfer. At high flowrates it is expected that the rates will tend to maximum values determined by either the rate limiting chemical reaction or diffusion in the condensed phase. In the present series of experiments it has been found that for any given gas composition the overall reduction rate goes through a maximum with increasing gas flow. The maxima, which occur at relatively low gas flows, are more than an order of magni- tude greater than those observed at high gas flowrates. The results of these and other experiments are presented and analysed. Possible rate limiting mechanisms in the reaction system and their implications regarding commercial reactors are discussed.

Jan 1, 1987

By Locke CA

Geophysical signatures of the Taranaki and Tongariro volcanoes reflect similarities in their age, composition and hydrothermal histories, but also reflect differences in host rock settings and edifice evolution. The Taranaki volcanoes have strong positive gravity anomalies showing that their edifices largely consist of dense andesite which reflects substantial lava production or dyke injection during construction and that large sub-edifice dykelstock complexes occur. In contrast, the Tongariro volcanoes have strong negative gravity anomalies indicating low density edifices of volcaniclastic material; no sub-edifice intrusions can be identified, probably because of the lack of density contrast with host basement rocks. Strong positive magnetic anomalies over the younger cones can mainly be attributed to near-surface andesite lavas or dykes whereas subdued magnetic effects are associated with hydrothermally altered zones within both edifices and sub-edifice intrusions.

Jan 1, 1995

University education in Australia is changing, driven by greater market orientation, reduced funding available per student, especially in the higher-cost minerals industry disciplines, and the call for more flexible delivery of subjects and courses to meet changing lifestyles and expectations. The opportunity exists for a true partnership to develop between industry, government and academia that will reshape minerals education in Australia and secure the future supply of the specialists industry needs to maintain international competitiveness. If this partnership does not emerge, it is anticipated that AustraliaÆs somewhat fragmented and unstable higher education system, especially in the disciplines of particular relevance to the minerals industry, will be put under further pressure so decreasing its effectiveness to produce quality graduates. The Minerals Council of Australia in 1998 published æBack from the BrinkÆ, a discussion paper which proposed strategies to build a world class minerals tertiary education system in Australia. Those strategies are now being implemented collaboratively with principal emphasis on the disciplines of mining engineering, metallurgy and earth science and as far as process is concerned, on the necessity to æcooperate to competeÆ. For metallurgy, the challenge is to integrate more closely undergraduate teaching with the existing world-class research centres and to link the tertiary institutions in such a manner that the strengths of all components are harnessed and then made available nationally in major population centres and at remote sites where appropriate. For industry the challenge is to build effective partnerships with the academic community that will enable and assist the agreed course of action to take place.

Jan 1, 2000

Access roads for haulage, construction or maintenance purposes are discussed with particular attention being given to the un- sealed "all weather" form of construction for Off-Highway applications. The service conditions experienced by the surfaces used in these roads is examined. These conditions are discussed in terms of the conventional engineering properties used for natural gravel material selection. Experience gained during the construction of a pipeline access track is used to illustratE material selection guidelines based on geological input and an understanding of good construction practices. TMITDnIll IrTT Ohl In many Australian situations off-highway haulage by wheel or track supported vehicles is carried on unsealed, gravel roads. Although the unsealed gravel road is the back-bone of the rural road network in Australia, in general, traffic loadings are relatively low compared to the off-highway unsealed haulage road. The cost of the haulage/access road construction component is one important factor in project planning which needs careful consideration. It is no longer acceptable that the initial rough exploration track be gradually upgraded so that it will eventually carry construction and maintenance traffic safely and efficiently. Fatal accidents and

Jan 1, 1982

By Amer S, Novais A. Q, Limpo Gil J

A proprietary hydrometallurgical ammonium chloride process for the recovery of not only zinc, but also copper, lead and silver from sulphidic zinc-rich concentrates has been developed at bench scale by CENIM and INETI (ex-LNET) as part of a research project supported by the Commission of the European Community (DGXII). This paper deals with the innovative chemical aspects applied to this chloride process and also with the more relevant data relating to mass balance, heat balance and process economics. Under mild temperature and oxygen pressure leaching conditions it is possible to extract practically all the zinc together with the other metals of interest and to precipitate simultaneously the solubilised iron fraction as goethite. The pH is kept close to neutrality in spite of the ammonia released in the leaching of the non-ferrous sulphides. A buffer effect is observed mostly due to the formation of zinc ammines which are very soluble in this medium. The zinc is further extracted by D2EHPA, the acidity being neutralised by the ammonia. Most of the ammonium chloride is naturally regenerated in this step. The zinc is recovered as zinc cathodes in a conventional sulphate electrowinning circuit. All the main raw material consumptions excluding the concentrate, such as oxygen, lime and ammonium chloride are linked to the sulphate formation in the leaching step which must be kept as low as possible by decreasing the reaction time under neutral conditions. The process analysis is complemented by the economic evaluation of a reference case. Difficulties encountered in finding a more convenient method of assessing the economics of the process in the absence of a reference price for a complex sulphide concentrate are examined and discussed. The reason why this analysis was performed with a much more optimistic metal prices scenario is also highlighted. The process economics are primarily dependent on the zinc market quotations and of course on the concentrate cost. Around 70 per cent of the total revenue is due to zinc sales. Assuming an internal rate of return of 17 per cent, the price of the concentrate can be as high as 255 $US/t for a plant capacity of 320 000 t/y (90 000 t/y of zinc).

Jan 1, 1993

By A Cooper

The current financial climate has given rise to fears that falling mineral prices and tight credit will force mining companies to cut back on production and new project development in a bid to cut costs and conserve cash. However, a prolonged squeeze on global supply can have only one result: a massive and potentially explosive demand for metals in the not-too-distant future. A resurgent global economy will also generate dramatic new demand for oil and energy, with a return to higher oil prices likely. How then should the mining industry plan for the future? In-pit crushing and conveying (IPCC) could lead the way as a partial or complete substitute for trucks. In 13 of 15 studies undertaken by Sandvik and Snowden, comparing IPCC with truck-optimised pit designs, IPCC generated operating savings ranging from US$0.18 to US$0.82 per tonne moved, compared to trucks. Trucks have higher operating, maintenance and energy costs than conveyors. New emission standards on diesel engines may make them more emission friendly but less efficient in terms of energy usage. With far more efficient energy use and cheaper operating costs per tonne moved than trucks, conveying offers an attractive alternative for the bad times ahead and into the apparent energy depleted future. When evaluating alternatives, a reasonable first step would be to conduct a scoping level study which analyses the differences in capital and operating costs between a truck and shovel operation and an IPCC solution. The study can also determine what type of IPCC is best suited to the particular mining application. The results can then be used to decide whether a more detailed study is justifiable. IPCC is a proven process that, with a fresh mindset, can make a significant improvement to mining operations. Sandvik (as an OEM with a full suite of IPCC equipment) can undertake these studies in ten working days in conjunction with Snowden or any other independent mine planner who knows how to schedule for IPCC. Because most mining industry personnel have been æborn and bredÆ on trucks and shovels û this paper focuses on some of the practical considerations necessary to make IPCC systems work that the Sandvik Technical Services Group has encountered during these studies.

Jan 1, 2009

By J W Shields

The aim of this paper is to present a concept or model regarding a particular geological environment where gold orebodies occur in the Pine Creek Geosyncline and indeed in many other pans of the world. The name GIGIACS (an acronym for Gold In Greywacke In Anticlinal CrestS) is proposed to label this concept or model. The name Saddle Reefs (which has been in use for many years) is used for gold-bearing quartz veins which often occur in conjunction with Gigiacs. Simple patterns formed by this type of mineralisation at the surface due to different configurations are illustrated. Some examples of Gigiacs and associated saddle reefs are presented from the Pine Creek Geosyncline together with examples from other parts of the world. This concept has been used successfully as an exploration tool and five examples are given. The terms Gicsiacs (for Gold In Carbonaceous Shale In Anticlinal CrestS) and Giliacs (for Gold In Limestone In Anticlinal CrestS) are also used.

Jan 1, 1994

By D J. Williams

Tailings management is typically constrained by many factors that are taken as given. These include the tailings production rate that must be accommodated, the desire to deliver the tailings cheaply and easily as a slurry using centrifugal pumps, and a tailings footprint limited by the desire to minimise capital costs leading to a rapid tailings rate of rise and a low settled density. Other constraints include wall raises being delayed due to limited capital, inadequate tailings water and rainfall run-off management, and the net present value (NPV) approach to capital expenditure that puts off expenditure at the expense of performance. All of these constraints result in the tailings occupying much more volume than is necessary, being difficult to rehabilitate, and not being capable of supporting a beneficial post-mining land use or function. Ultimately, such constrained tailings storage facilities will assume very large dimensions, but each will typically be developed as a series of smaller storages that are filled rapidly and added to progressively. The optimal stage to efficiently recover process water is in the process plant, but this is limited by the desire to use centrifugal pumps rather than the more costly positive displacement pumps, which also require greater management of tailings deposition. Process water can also be recovered from the tailings storage facility (TSF) decant. Tailings water that is not recovered from the plant or the decant will be lost to entrainment within the tailings, seepage to the foundation or through the wall, or evaporation. However, tailings water is not always suitable for reuse in the plant, particularly when it becomes contaminated by the processing, and it may simply be stored on the TSF. This will exacerbate the seepage of contaminated water to the environment, and will limit the densification of the tailings that would otherwise occur due to desiccation of the tailings on exposure. If a larger tailings footprint were developed early, cycling of tailings deposition in thin lifts between a number of cells could occur, maintaining the dormant cells dry to enhance desiccation and densification, and ultimate rehabilitation. The end result would be a much reduced stored volume of tailings, the potential for upstream raising, and ease of rehabilitation to a high level. The higher initial capital cost would be overtaken by reduced ongoing capital, operating and closure costs.CITATION:Williams, D J, ?2014. An alternative whole-of-life approach to tailings management, in Proceedings Life-of-Mine 2014 , pp 285–298 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By V Narayanaswamy

SustainabilityÆs imperative of economic development in tandem with social advancement and environmental protection is widely accepted, but much debate remains about the practical implications for the minerals processing technologies and practices for the future. Experience in other industry sectors however suggests that sustainability can be a value-adding framework for innovation in processing technologies, business models and management systems. This position paper explores how sustainability can drive innovation in minerals processing, by reviewing pertinent ideas and experiences gained in non-minerals sectors. Sustainable innovations can generally be broadly ranked from incremental to transformative, with each category having its own typical improvement potential, timescale and technological and operational challenges. This leads to a æmud mapÆ for sustainable innovation in minerals processing with three distinct tracks: eco-efficient operations; sustainable plant design and sustainable processing. Competing models for the sustainable innovation process through either forecasting or back-casting, have in common the strong reliance on vision, perspective and competency, which in turn highlights the importance of sustainability frameworks. Such sustainability frameworks provide normative goals and option elicitation prompts to assist with the analysis of current processes and scoping of more sustainable alternatives. A comparative analysis of five prominent environmental sustainability frameworks revealed three cross cutting sustainability themes that challenge current resource processing technologies and practices. These are: fate of materials (zero dissipation of materials); compatibility of materials and processes; and materials intensity of industrial products and processes. Although the sustainability concepts presented in this paper have not been extensively road tested in the minerals processing industry, there is ample evidence that recent initiatives in the Australian resource sector illustrate the applicability of the proposed framework. It is therefore argued that more in-depth assessment of sustainable innovation concepts would be a valuable contribution to the sustainable resource processing theory and practice.

Jan 1, 2004