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By W Schauenburg

The increasing problems associated with the disposal of waste and the potential for use of by-products as underground filling material is a subject which is relevant not only to the coal-mining industry. The progressive scarcity of surface disposal facilities for by-products and waste has now become a problem in all sectors - not only for the mining industry. The considerable capacity offered by underground cavities which exists in various mining branches present an extremely promising potential in this context. The backfill process for coal mining developed by DMT in co-operation with Ruhrkohle AG make use of the cavities which are offered by the extraction of coal. It consists of several stages: The fine-grained by-products, such as sludge, filter cakes, fine refuse, ash and flue-gas cleaning residues are processed on the basis of specified formulations in metering, blending and pump facilities on the surface to produce pumpable pastes with precisely defined flow characteristics. On Walsum Colliery of Ruhrkohle AG up to 200 m3/h stowing paste is conveyed into the mine in pipes with diameter of 200 mm (8"). The delivery pressure of the pump operating on surface in conjunction with the hydrostatic pressure of the shaft pipe - amounting in total to as much as 25 MPa - makes it possible to convey the stowing material for a distance 12000 m underground up to the workings without any need for additional booster pumps. Via a pipe installed in the face, the paste is pressurised into the cavities in the specially fragmented rock in the mined-out zone well behind the support. Consistent use of stowage of caved-in goafs makes it possible to reduce surface settlement above the workings. Fires in the stowed rock are either smothered or completely prevented thanks to the exceptional air-tightness in the caved goaf and the cooling effects of the slurry stowage. The reduced danger of fire, the preventation of air-leakage and the positive effects on gas emission from the coal improve safety in the workings.

Jan 1, 1998

The Electricity Commission of New South Wales is the largest single user of coal in the State, burning some 8.5 million tonnes during 1972-73. This coal is converted in power stations into electrical energy which is then distributed throughout the State and supplies the electricity requirements of 99% of users in New South Wales. Barring any major change in energy consumption growth, or change in the current mode of power generation, the consumption of coal by the Commission is estimated to have a doubling period of from 10 to 14 years. Coal is used to generate up to 87% of the electrical energy sold, the balance being obtained from hydro gen- eration, mainly in the Snowy Mountains, and, to a much smaller extent, from diesel generation at Broken Hill. A very large proportion of this coal is consumed in pulverised fuel boilers in the Commission's power stations, located mainly on the various coalfields of New South Wales. Coal supplies are drawn from a large number of mines, some owned or controlled by the Commission, others being owned by public companies. The coals used, originate from at least ten different seams located in the northern, western and southern coalfields of New South Wales, and therefore have a wide variety of properties and characteristics. To ensure an adequate fuel supply well into the future, the Commission is continuously engaged in coal prospecting in various areas. Bore data is used in assessing coal reserves and is also the basis of economic studies for their possible future exploitation. The numerous coal cores obtained during drilling operations are carefully tested and analysed in order to assess their suitability for power generation purposes, and to provide data for the design and operation of boiler plant using these coals. In existing power stations coal deliveries are systematically sampled and tested for quality control, for pay- ment of purchases based upon certain quality parameters and to check for any possible plant operating or main- tenance problems that might arise from the use of the particular coals. Almost all the properties of coal that may be necessary in the Commission's work are obtained using standard testing procedures carried out by the Commission's chemists, in laboratories located at the various power stations or at its Central Laboratories in Pyrmont. Where specialised analysis or testing is required, this is ordinarily undertaken on a commercial basis by outside bodies, expert in the particular field. The significance of the various properties of the coal for use in p.f. boilers is outlined and related to their proper application to boiler plant design and to plant operation.

Jan 1, 1975

By M D. Melville, B C. T Macdonald, T D. W

The surface waters in regions with acid sulfate soils (ASS) can contain high concentrations of acidity and dissolved metals. These soils cause problems for agriculture, construction and development. The water can be neutralised through many techniques, however a technique that is low in maintenance and low in cost is most desirable. Due to the vast spread of ASS along AustraliaÆs coastline an expensive and high maintenance solution would not be cost-effective. In this study, a passive treatment system that has been used to neutralise acid rock drainage has been applied to treat ASS water. This system is commonly referred to as an oxic limestone drain (OLD) or an anoxic limestone drain (ALD) depending on the waters dissolved oxygen concentration. The system that has been developed for ASS has a similar closed system to the OLD or ALD, that traps the carbon dioxide which forms when limestone reacts with acidic water. It has been called a closed tank reactor (CTR) and is constructed by placing limestone into an airtight tank. A common problem that will occur when acidic water with a high concentration of dissolved metals reacts with limestone is the formation of metal oxy-hydroxide precipitates. These precipitates can coat or armour the limestone and reduce its reactivity. To minimise the accumulation of precipitates in the CTR, perforated subdrains have been installed. It is anticipated that high water pressure and flow through the subdrains will remove some precipitates. A sump has also been installed at the base of the tank to collect precipitates that settle under gravity. The CTR has been tested for 70 days at a sugar cane farm located at McLeods Creek, NSW. Within this time the sump and subdrains have been used to flush the system. An orange solution was produced during flushing and it is believed to contain iron and aluminium precipitates. The initial performance of the CTR raised pH by at least one unit. Almost all dissolved aluminium was removed and more than half the dissolved iron. The total titratable acidity ranged from 17 - 92 mg/L CaCO3 in the initial month of monitoring. After passing through the CTR the acidity was reduced to zero. The performance of the CTR during the last few days of monitoring decreased. This is believed to be due to a pulse of water with higher acidity and dissolved metal content that lasted a week. In this pulse, the acidity reached 307 mg/L CaCO3 and the total dissolved aluminium reached a maximum of 24 mg/L. Higher concentrations of dissolved metals may have been the cause for lower performance due to increased precipitation and coating on the limestone.

Jan 1, 2003

Education and Training for the minerals industry has been identified as one of the key priorities by the AusIMM and many closely related groups. The AusIMM Education Taskforce has been engaged, through a visioning exercise, in evaluating what minerals education and training should look like by 2025. A common recurring theme is that for minerals education and training to be efficient and effective into the future, it needs to be comprehensive and inclusive. Some previous attempts to achieve efficiency and effectiveness have had limited success, mainly due to approaching the issues involved from a narrow, singular perspective. This paper outlines that the achievement of the desired outcome may require an approach that parallels the same techniques that are used for multi-dimensional mine planning, treating tertiary minerals education and training in a similar way to the planning involved for a complex orebody. Just as efficient and effective mine planning requires engagement and understanding of many factors, so too does engagement with tertiary minerals education and training. The major factors that need to be considered are outlined in the paper, including: levels of tertiary education and training; Australian Qualifications Framework (AQF), Levels 1 to 13: systems of minerals education and training, such as higher education, (mainly universities), industry/professional associations and licencing requirements, vocational education, (mainly TAFE) and workplace programs; types of minerals or mining methods involved; volume of delivery; stage in the flow sheet, (geology, mining, beneficiation, extraction, refining). For comprehensive mine planning there is the need to develop links or roadways and openings between different levels of a mine. Similarly, to achieve a comprehensive tertiary minerals education and training model, there is a need to develop pathways, recognition and credit transfer between the various levels and components of minerals tertiary education and training.

Jan 1, 2005

By S Zaffron, O Loffredi

A critical concern of any mining company today is its relationship with the different stakeholder groups impacted by the operational activity û communities, unions, vendors, local partners and competitors, local and federal governments, interest groups and non-government organisations. What ten years ago would have gone unnoticed, now, and even more so in the future, can drastically impact the profitability and even existence of a mining operation. This paper describes the development and delivery of a new paradigm for creating effective external stakeholder relationships. We report on the actual measurable results of an integrated and highly complex initiative led by Lonmin Plc (Lonmin) and Landmark Education Business Development (LEBD) that significantly altered the nature of the relationship with the stakeholders. Given the nature of the long-term investment required in a mining operation, any breakdowns or surprises in its relationship with external stakeholders brings with it the potential for major loss. The transformation of executive and senior management and community leadership was required to enable them to be effective in managing this complex set of circumstances.

Jan 1, 2006

Australian wheat belt agriculture is causing a decline of its natural resource base. The major problem, salinity, arises from a small reduction in water consumption by agricultural crops compared to what prevailed under the prior native vegetation. This causes groundwater accumulation which, in the low relief landscapes of the wheat belt, is leading to extensive surface saturation in low landscape positions and dramatic, destructive change in the hydrological behaviour and habitat of streams and rivers. The ability of agriculture to invest in salinity control is severely limited by its long-term decline in its terms of trade. Extensive planting of perennial vegetation has the potential to increase water use and arrest the salinisation process. If these perennials were also commercially attractive, the cost of salinity treatment could be minimised. Given the difficult commercial position of food commodities, it is logical to develop ænon-foodÆ perennial crops, in particular woody crops suitable for industrial products. This paper looks at the example of Sweden, where there has been a generation of investment in developing forest harvest residue recovery, and short cycle woody crops for bioenergy, but with only limited success. In contrast, secondary residues (processing wastes) from forestry industry are readily saleable for low value uses like bioenergy. This suggests that the model woody crop must have a higher value fraction to facilitate delivery and commercial use of its lower value fractions. This model is being emulated in the development of native mallee eucalypts as short cycle woody crops in Western Australia. Some $50 million has been expended on mallee development in the past decade and this has culminated in an engineering demonstration of integrated processing. The putative high value products are activated carbon and eucalyptus oil and the residue (plus waste heat) will be converted to electricity. The potential scale on which crops of this type would be required to achieve salinity control means that many more high value and residue products will have to be developed. Metallurgical charcoal appears to be a promising product option.

Jan 1, 2006

By E Yurakov, D J. Ashelford, M I. Slate

The push for increasing coal production rates continues to place increasing demands on mine management to safely and effectively control seam gas. Gas drainage strategies applied vary in both effectiveness and form. Methods employed are a function of assessed risk, gas reservoir characteristics, surface and underground access, budgetary constraints and gas utilisation potential. With the aim of establishing and optimising the effectiveness and efficiency of gas drainage systems, Australian coal miners in cooperation with gas management specialists are embracing the use of gas reservoir simulators and gas emission models. This paper discusses the evolution of gas drainage practices in Australian underground coal mines and the role of gas reservoir assessment methods in optimising gas drainage systems and gas production forecasts.

Jan 1, 2005

By T Seifert, P Krolop, K Niiranen, S Gilbricht

The Per Geijer iron oxide apatite deposits (IOA) display significant potential mineral resources for Luossavaara-Kiirunavaara AB (publ), known as LKAB. LKAB continuously mines magnetite/hematite ores in northern Sweden for almost 130 years. The Per Geijer deposits reveal a high phosphorus content and vary from magnetite-dominated to hematite-dominated ores, respectively. Furthermore, they show a large variation in texture, mineral composition, and relation to wall rocks. The high phosphorus concentration of these ores results from highly elevated content of apatite as gangue mineral. Reliable, robust, and qualitative characterisation of the mineralisation is required as these ores inherit complex mineralogical and textural features. For this purpose, comminution tests at laboratory scale in combination with scanning electron microscopy-mineral liberation analysis (SEMMLA) were carried out. Based on this work, significant information on the modal mineralogy and degree of liberation of minerals of economic interest (eg magnetite, hematite, and apatite) were obtained. Results show that there is a difference in the degree of liberation of magnetite and hematite between ore types. This seems to be dependent both on the size fractions and the dominance of each iron oxide in the individual ore type. The amount of gangue minerals seems to have no significant impact on the degree of liberation after comminution. Apatite is generally best liberated in ore types associated with silicates, regardless of magnetite or hematite dominance. Based on the results of this study it can be inferred that a high degree of liberation of the minerals of economic interest can be achieved. However, results need to be verified with further beneficiation steps such magnetic separation, apatite flotation and possibly reverse silicate flotation.

Nov 8, 2021

At the Nikkel og Olivin nickel mine near Narvik, Norway, Outokumpu has been the operator since 1993. The mine was opened in 1989 and in 1992 Outokumpu commenced operations to secure concentrate deliveries to Harjavalta's nickel smelter in Finland. Annual production is about 740 000 tonnes of nickel ore grading 0.5 per cent Ni, about 25 000 tonnes of nickel concentrate and about 2800 tonnes of nickel metal. All production comes from underground operations which makes Nikkel og Olivin AS perhaps the lowest grade underground nickel mine in the world today. Production is currently from one of two orebodies, which is known as the Western orebody. The Eastern orebody was worked out by 1995. During Outokumpu's operational period the Western orebody has been delineated and taken to production. The underground exploration and definition drilling involved about 15 000 in of diamond drilling, which was carried out during a nine-month period. Following this a feasibility study was undertaken and production commenced. Improvements were made to the mining methods. Previously the mine utilised open pit equipment underground and this resulted in an enormous amount of additional tunnelling. Grade control and ore delineation were previously based on sparse diamond drilling and all geological information was processed manually. The improvements included the use of underground sludge drilling to increase the amount of geological information, the of a new computer system for grade control and mine planning, new automated underground longhole drilling equipment and the of underground mining equipment which reduced the size of the drives. These changes produced a marked increase in the efficiency of the underground Mine.

Jan 1, 1996

By B Ascott, J Kennedy, A White

At mines with low tonnes per vertical metre, like the Jundee Mine in Western Australia, operated by Newmont Asia Pacific, high development rates across multiple mining areas are critical to achieving the delivery outlined, or promised, in the annual business plan. The challenge is to deliver the short-term requirements while keeping in balance with the long-term strategic direction. Newmont Jundee has developed a system called æMine Planning by QuartersÆ that integrates the planning process with the business process in one end-to-end continuum. Short-, medium- and long-term schedules are reviewed and updated by applying four integrated subprocesses, which capture new information as it becomes available. The four subprocesses are: resource development planning û evaluating mineral resource,reserve development planning û preliminary design for new reserves,mine operating planning û final mine design for reserves, andmine production planning û detailed plans for stoping a proved reserve. Commercial mine planning software is used in these subprocesses to facilitate the flow of information into a central storage æhubÆ for uploading into the rolling business plan. A regular and consistent quarterly review helps to identify and qualify areas of business risk at an early stage, allowing time to plan for contingency and minimise the impact of the risk.

Jan 1, 2008

Water is a key resource input to copper heap leach operations in both quality and quantity. A number of recent developments in analysis of the technology have shown that water consumption can be optimised. The leach consumption has been generally considered in terms of minimisation of the evaporative loss by changing the application method (drippers or wobblers). Modelling of the irrigation effects on leach rate has shown that the poorer surface coverage from drippers has an adverse effect on the leach extraction rate. This is particularly evident in the early part of the leach. The use of different irrigation systems during alternate parts of the leach cycle can have benefits in minimising the water consumption without an unacceptable outcome from extended extraction times. By combining the leach rate effect with the evaporative loss estimates, an economic decision matrix can be generated to allow the operator to select an appropriate leach irrigation strategy, combining both irrigation delivery and irrigation rate. In the SX-EW plant, the total quantity of EW bleed and SX scrub stage bleed (both for iron control) can be reduced to an absolute minimum. The economic minimum may be different depending on the cost of producing the high-quality water used to replace the bleed streams. Adjustment of the SX process, in particular use of multiple entrainment control steps, can provide significant reductions in the total bleed and make up requirements.

Jan 1, 2003

The Mining Act (1992) and the Petroleum Act (1980) provide for the Government of Papua New Guinea (PNG) to take up equity holdings in mining and petroleum projects. The price the Government pays for its share is based on the historical cost of exploration and development on the project to the date of government equity acquisition. The equity level to be acquired is not fixed and ranges up to 30o for mining and up to 22.5s for petroleum at the discretion of the Government of the time.The objective of this paper is to examine the pros and cons of State equity holdings in PNG from the point of view of both the State and the developer. Using an economic model of the PNG mining taxation system an assessment is made of the effective return on investment received by the State from such equity holdings. The results are compared with government revenues from other taxation measures.

Jan 1, 1994

By K F. Tang, J-W Li

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Xiong’ershan district in the southern margin of the North China Craton (NCC) contains more than 20 gold deposits hosted in the late Neoarchean to early Palaeoproterozoic amphibolite facies metamorphic rocks or late Palaeoproterozoic unmetamorphosed volcanic rocks. Gold mineralisation consists mainly of auriferous quartz veins and disseminated ores in hydrothermally altered zones, with additional gold mineralised breccia pipes. Gold orebodies are strictly controlled by secondary- or higher-order brittle/ductile-brittle faults. Isotopic dating reveals two separate episodes of gold mineralisation: the Shanggong and Dianfang deposits formed in the range of 236 ± 1.4 to 202 ± 18 Ma, whereas the Gongyu, Qianhe and Qiyugou deposits formed between 135.0 ± 0.5 Ma and 124.0 ± 1.0 Ma. Stable isotope and noble gas geochemistry studies indicate that the Triassic gold deposits were precipitated from deeply-sourced, low-salinity fluids at 250–350°C, but whether the fluids were mainly derived from metamorphic devolatilisation or magmatic degassing remains unresolved. In contrast, the Early Cretaceous deposits most likely precipitated from a dominantly magmatic fluid, although metamorphic and meteoric components cannot be ruled out. Results from this study, when combined with regional geological and geochemical data, suggest that the Triassic gold mineralisation was generated by the deformation associated with the collision between the North China and Yangtze cratons, forming the Qinling-Dabie orogen. In contrast, the Early Cretaceous gold veining was a result of lithospheric destruction of the NCC, a process initiated by plate subduction from both the south and north since late Palaeozoic but ultimately triggered by the westward subduction of the palaeo-Pacific plate in the late Mesozoic. This study helps to reconcile the long-term debate on the timing, genesis and geodynamic setting of gold mineralisation in the Xiong’ershan and other districts along the southern margin of the NCC.CITATION:Li, J-W and Tang, K F, 2015. Gold deposits in the Xiong’ershan District, Southern North China Craton – products of Triassic deformation and Cretaceous craton destruction, in Proceedings PACRIM 2015 Congress, pp 341–344 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Ormsby W. R, Nicholson P. M

Woodcutters is a polymetallic vein-style deposit hosted by sediments of the Palacoproterozoic Whites Formation which forms part of the sedimentary sequence in the central Pine Creek Geosyncline. Past production and identified resources total over eight million tonnes at 5.5 per cent lead, 12.1 per cent zinc and 110 gA silver. The local geology is influenced by Archaean basement highs; the Rum Jungle and Waterhouse Complexes. Unconformably overlying basement are interbedded clastic and crystalline carbonate units (Batchelor Group) representing cyclic changes in the depositional environment. These exhibit onlapping features with the underlying rocks. Sediments of the overlying Frances Creek Group suggest a quiet period during subsidence and subsequent increase in water depth (the carbonaceous dolomitic shales and the interbedded dololutites of the Whites Formation) followed by proximal uplift resulting in the inundation of turbiditic flows (Acacia Gap Quartzite). All of the Palaeoproterozoic rocks show evidence of being affected by penecontemporaneous, basement circling faults with steep dips. The stress regime during the deposition of the Frances Creek Group was characterised by alternating episodes of thrusting and transpression. Periods of relaxation also occurred. The compression resulted in major NS strike-slip (transpressional) faulting, en-echelon NNE trending folds and NW-SE tensional cross faults. Thrusting produced N-S striking, steep dipping reverse faults and a possible decollement immediately above the Batchelor Group. Relaxation is evidenced by the intrusion of lamprophyre dykes and dolerite sills (Zamu Dolerite). Mineralisation at Woodcutters occurred in faults within the Whites Formation, probably synchronous with deformation and the deposition of the upper parts of the Frances Creek Group. Greenschist facies metamorphism occurred as the rocks were further buried. Several massive sulphide bodies occur at Woodcutters. A number of features influence the location and shape of these bodies. They are: ò the N-S transpressional faults and in particular associated dilation zones; ò intersection of the N-S transpressional faults with the axial plane of the NNE trending Woodcutters Anticline; ò intersection of the N-S transpressional faults with the NW-SE cross-faults; ò intersection of dololutite rich units with the NS transpressional faults where local replacement takes place; ò thickening of the lithological units in the vicinity of the anticlinal axis; and ò the anticline doubly plunging to both the north and south. The mineralisation exhibits vein-like features as well as epigenetic textures. Its boundaries are sharp, its thickness varies rapidly down dip and along strike, and no alteration halo exists though stringer veins of quartz-carbonate-pyrite ¦ sphalerite/galena occur in close proximity. A number of sulphide mineral assemblages have been recognised, each separated by periods of deformation and partially replacing the earlier assemblages. Vertically continuous zonation patterns highlight the presence of rich galena-sphalerite-silver in zones of maximum dilation and pyrite-arsenopyrite-gold concentrated at the along strike peripheries. The genetic model proposed has the mineralisation occurring whilst the transpressional regime was active. It was deposited from the same fluid that elsewhere in the Geosyncline formed the stratiform deposits higher in the sedimentary pile. Hydrocarbons sourced from the organic-rich Whites

Jan 1, 1994

By R Carreau

The results of a detailed acid rock drainage (ARD) prediction program were used to revise the waste rock segregation criteria at the Restigouche open pit mine. Waste rock at the site was predominately derived from altered volcanic rocks that hosted a massive sulfide lead/zinc orebody. The program assessed the five years of drainage chemistry from both the potentially acid generating and the non-acid generating waste rock storage facilities in addition to laboratory-based kinetic test results. Material-specific leaching characteristics including relative metal-release rates and neutralisation potential depletion rates were determined from 12 laboratory-based kinetic tests. Solid-phase analyses indicated that, although pyrite was typically the most abundant sulfide mineral in the waste rock, its abundance varied significantly as documented by total sulfur contents ranging from 4.0 per cent. Kinetic test results were used to establish revised waste rock segregation criteria based on total sulfur content and neutralisation potential. The revised criteria maintain that waste material with a total sulfur content 4.0 per cent as potentially acid generating. When present in sufficient quantities, ankerite provided an effective source of neutralisation potential for the range of observed sulfide oxidation rates. Kinetic testing documented that up to 6 kg CaCO3/t was ineffective at neutralising acidity in samples that contained >4 per cent S. The carbonate molar ratio measured from the humidity cells was adjusted to reflect the stoichiometry of the ankerite and applied as an NP/AP criteria for waste rock containing 0.1 <S per cent <4.0.

Jan 1, 2003

By D Craw, P Upton

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Southern Alps of New Zealand and the mountains of Taiwan are both young transpressive orogens characterised by rapid uplift and exhumation, high heat flow and vigorous surface processes. Comparing and contrasting the two provides an ideal framework through which to explore the structural and lithological controls on fluid and gold mobility during collisional deformation. Both have two fluid flow systems centred about their drainage divide with shallow topographically-driven meteoric water above a deeper flow system dominated by mineralising rock-exchanged fluids. Despite similar tectonic settings, the distribution of heat flow, hot springs and veins in the two orogens are different. Taiwan has higher heat flow, distributed hot springs and localised veining whereas the Southern Alps have a narrow heat flow anomaly, localised warm springs and widespread veining. We use three-dimensional numerical models to evaluate key parameters that affect fluid flow and gold mineralisation. Models show that differences in crustal strength and thickness affect the locus, scale and rate of crustal fluid flow and hence influence gold deposition at a variety of scales. We explore how surface topography can lead to localised changes in the stress state, facilitating the switching of principal stresses and hence vein orientations.CITATION:Upton, P and Craw, D, 2015. Modelling structural and lithological controls on the mobility of fluids and gold in orogenic belts – examples from New Zealand and Taiwan, in Proceedings PACRIM 2015 Congress, pp 189–192 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Muto S, Okada S

At Tamano Smelter, part of the furnace settler is electrically heated by electrodes placed internally. This practice provides good control of the settler conditions. The authors have been investigating improvements in furnace operations, especially to decrease the copper content in the slag discarded from the settler. The important operational points on the control of magnetite in liquid matte and slag are discussed on the basis of the thermodynamic calculation method developed by Prof. S. Goto. The behaviour of magnetite in the practical furnace has been studied by using a torsion magnetometer and a solid electrolyte oxygen-sensing cell.

Jan 1, 1980

The Newcrest Mining Limited Telfer Gold Mine consists of an underground sublevel cave (SLC) operation located 734 m directly below active open pit operations. Open pit and underground current production rates are 50 million and 5.7 million tonnes per anum (Mt/a) respectively. The SLC was initiated in late 2006 with breakthrough planned to occur on the 5484 bench of the west wall in late 2009. Risk to the south ramp was identified during this time, resulting in the construction of the north ramp. The SLC was continually tracked from initiation with a suite of monitoring systems and managed with a Major Hazard Management Plan (MHMP) and associated Trigger Action and Response Plans (TARP). At breakthrough the eastern limb of the cave was located within a 70 m horizontal distance from the south ramp. The south ramp was closed in October 2009 due to significant slope deformation, extensive cracking in the berms and batters between the ramp and breakthrough bench and a major failure 250 m to the north of the cave breakthrough. Wall response was first identified from slope deformation measurements taken by the wall monitoring radar in May 2009, at which point the SLC was 160 m from breakthrough. The impact of the SLC on the slope is a unique case with the monitoring systems in place able to provide data on the slope reaction to the SLC progression. This paper will discuss the management of the south ramp such as the early interpretation of risk associated with cave breakthrough, monitoring systems implemented to track the cave progression and wall deformation, data integration and interpretation and risk management. Following the closure of the south ramp further instrumentation programs and risk assessments were conducted to determine the risk of re-opening this haulage route. The outcomes of this program will also be presented.

Nov 25, 2010

By S Q. Zhao, J H. Wei, Z X Zhao, S N. Liang

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The degree of regional denudation is one of the most important factors for judging the preservation potential of ore deposits as it can be used in a predictive manner to help guide exploration. There are many methods available to judge the denudation degrees of mineral deposits. These include regional geochemical assessment methods, the characterisation of primary lithogeochemical halos, the thermoelectricity of pyrite and apatite fission-track methods. Each method has its specific principles, application scopes, limitations and successful cases. Based on previous studies, this paper discusses the research progress on assessments of ore deposit denudation in China and provides a summary and discussion of various methods that can be employed.CITATION:Liang, S N, Wei, J H, Zhao, Z X and Zhao, S Q, 2015. Review on the ore deposit denudation degree, in Proceedings PACRIM 2015 Congress, pp 65–68 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By J-S Han, J-M Yao

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Shagou deposit is located along NE-trending faults within the high-grade metamorphic basement of the Xiong’er Terrane in the Qinling orogenic belt. It is a large Ag-Pb-Zn deposit hosted in the Taihua Supergroup and has proven reserves of 1.54 Mt of ore with grades of 767 g/t Ag, 13.24 per cent Pb and 4.31 per cent Zn. The hydrothermal ore-forming process can be divided into early quartz-pyrite, middle quartz-polymetallic sulfides and late quartz-carbonate stages. Four types of fluid inclusions (ie pure carbonic, carbonic, pure aqueous and aqueous) can be distinguished in quartz. Fluid inclusion, hydrogen, oxygen and sulfur isotope systematics indicate that the ore-forming fluids are initially deeply sourced metamorphic water with meteoric water gradually mixed in the later stages. Sulfur isotope data show that the ore-forming fluids originated from both the Taihua Supergroup and the sedimentary successions of the Guandaokou and Luanchuan Groups (CSC) located to the south of the Machaoying Fault. A genetic model of the Shagou deposit is proposed as follows: CSC subducted northward along the Machaoying Fault beneath the Xiong’er Terrane during the Mesozoic collision between the North China Craton and South China Block. Subsequent dehydration resulted in the devolatilisation of fluids rich in CO2. These fluids migrated upwards, reacted with the Taihua Supergroup and formed the Shagou deposit.CITATION:Han, J-S, Yao, J-M and Chen, H, 2015. Fluid inclusion and isotopic constraints on the mineralisation of the Shagou Ag-Pb-Zn deposit, Henan Province, China , in Proceedings PACRIM 2015 Congress, pp 615–618 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015