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The quality of the external water source for a mineral processing plant may influence the extent to which the environmentally desirable practice of recycling of water from plant products is possible. This is particularly likely for froth flotation plants where the chemical quality of the water may affect the plantÆs performance. The quality of the external water source or the recycled water can be improved by a water treatment step, and in turn the extent of recycling which can be tolerated is able to be influenced. The quality of the external water can range from very high quality, soft water derived from melting snow, to poor quality, hard water (high levels of dissolved calcium and magnesium) from underground aquifers, and to even lower quality sea water (very high levels of dissolved species including sodium chloride). It can be noted that some underground water is more saline than ocean water as well as containing high levels of dissolved calcium and magnesium. Occasionally, a different source of water is utilised in the wet and the dry seasons. Increasingly, sewage water from cities is becoming a potential external water source with sustainability implications. If the initial quality of the external water is high, the scope for recycling of water from all the products is maximised. Such reuse or recycling of water from the products allows chemical species from oxidation of the ore and from other inputs to the process such as reagents to increase in concentration in the water returned to the plant. Such accumulation of species can have negative effects on the performance of a process such as froth flotation but instances of positive effects exist. Some reagents which are used in flotation plants such as lime or sodium carbonate also happen to be commonly used for independent water treatment plants. Hence, the flotation process may inadvertently provide some aspects of water processing. Where the quality of the water in the feed to a mineral processing plant (external water plus recycled water) is not an issue, more powerful solid-liquid separation processes can be considered to maximise the removal of water from the products and its reuse. Such processes may also have complementary benefits in a sustainable mineral industry by, for example, producing a tailing stream with a higher per cent solid value which is more suitable for safe storage on the surface or underground. This paper documents findings on the effect of water quality on the flotation process. It also considers current directions of change in the need for increased removal of water from plant products. It then considers the implications of these trends for maximisation of water recycling by such operations.

Jan 1, 2003

Caving is the lowest cost underground mining method, provided that drawpoint spacing, drawpoint size and ore handling facilities are designed to suit the caved material and that the drawpoint horizon can be maintained for the draw life. In the near future several open pit mines that produce in excess of 50 000 tons per day will have to examine the feasibility of converting to low cost, large scale underground operations. Several other large scale, low grade underground operations will experience major changes in their mining environments as large dropdowns are implemented. These changes demand a more realistic approach to mine planning than has occurred in the past, where existing operations have been projected to increased depths with little consideration of the change in mining environment that will occur. As economics force the consideration of underground mining of large, competent orebodies by low cost methods, the role of cave mining will have to be defined. In the past caving has generally been considered for rock masses that cave and fragment readily. The ability to define cavability and fragmentation, the availability of large, robust LHDs, a better understanding of draw control requirements, improved drilling equipment for secondary blasting and reliable cost data have shown that competent orebodies with coarse fragmentation can be exploited by cave mining at a much lower cost than with drill and blast Methods.

Jan 1, 1995

By G Chitombo, G Lewis

The knowledge of the expected run of mine (ROM) fragmentation during the feasibility study of a green field site is essential for the design of downstream crushing and milling processes. However,the prediction of blast fragmentation can be a challenging process due to the uncertainty related to the blast design and rock mass parameters. In general,a number of possible blast designs are considered in a feasibility study,with factors such as bench height and blasthole diameter influencing the design. Rock mass parameters are normally derived from a limited number of geotechnical diamond drill cores. Although diamond drill core can provide detailed information concerning intact rock strength (unconfined compressive strength and point load),it provides limited structural information to predict the in situ block size distribution of the rock mass. The in situ block size is an essential input to the prediction of the fragmentation distribution, in particular the coarse end. This paper outlines the methodology of blast fragmentation modeling undertaken for a green field feasibility study at the Riska gold deposit in Indonesia. The favoured milling process for the feasibility study was dump leaching,with no crushing of the ore material extracted from the pit. For this reason,blast fragmentation was a critical issue to be addressed by the study. A range of blast designs were considered with bench heights and blasthole diameters ranging from 4 m to 7 m and 76 mm to 102 mm respectively. Rock mass data was obtained from 19 diamond drill cores across the deposit (total drill length approximately 2200 m). Intact rock strength was estimated from qualitative strength descriptors,while the in situ block size distribution of the rock mass was estimated from the Rock Quality Designation (RQD) of the core. The methodology of fragmentation prediction involved a number of steps including the estimation of rock mass parameters from diamond drillhole data including the estimation of the in situ block size, delineation of blast domains within the deposit,and the assessment of the impact of various blast design parameters and rock mass variation on the predicted fragmentation distribution. The modelling process for the Riska green field site highlighted the need for additional rock mass data to be collected post feasibility stage and once the development of the mine commenced.

Jan 1, 2004

By McNay L. M

Two field studies to monitor fill pres sures and vein-wall deformation were conducted in mines of the Coeur d'Alene mining district in Idaho. Both operations employed cut-and-fill mining techniques in nearly vertical veins aver- aging 10 feet in width, and backfilled with classified mill tailings. Hydraulic pressure cells were used to measure transverse, longitudinal, and vertical pressures within the backfilled stopes. Rock bolts extending into the manways and mechanical closure devices were used to monitor vein-wall convergence. Continuous recorders were used with selected pressure cells to prolong the life of the installation. Transverse pressures in excess of 600 psi and stope wall closure up to 22 inches were re- corded. Closure rates were higher at midheight of the stope than they were near either sill, indicating that the vein walls react similarly to a beam supported on each end.

Jan 1, 1973

By Cocker A, Kavetsky A

A numerical model describing blast fragmentation and damage in three dimensions has been developed at the Julius Kruuschnitt Mineral Research Centre (JKMRC) and applied to numerous blasting operations in mines throughout Australia. The model combines the rock structure (summarised by block size distribution) with blast strain energy and uses comminution theory to calculate the resultant block size distribution. The model distinguishes between rock breakage and failure, the former being defined as size reduction and the latter as block dissassembly. The background and basis of the model are discussed in detail and three case studies presented describing the application of the model to explosive performance evaluation, explosive selection and drill selection in Australian mining operations.

Jan 1, 1990

By B Lyne

In 1990, the Queensland mining industry had come to the conclusion that new safety and health legislation based on risk identification and control was required if the mining industry was to be effectively and efficiently regulated. In particular stakeholders in the coal mining industry had arrived at this opinion after the industry had suffered a number of major underground explosions over the 14-year period between 1972 and 1986. Also by 1990, a general consensus had emerged across both the coal and metalliferous mining sectors that mining industry was over regulated and, more to the point this over regulation did not encourage industry to identify and address the underlying causes that had led to a cycle of major mining accidents in the state. The prevailing opinion was that the prescriptive legislation left the ownership of risk management with the regulator and not with the mine operator. This paper discusses the background to the development of the Queensland Coal Mining Safety and Health Act 1999 and the Mining and Quarrying Safety and Health Act 1999 and the progress made in improving safety and health since the statutes came into force on the 16 March 2001. The paper discusses the issues that had to be addressed during the development of the legislation including the interaction with other legislation based on based on risk management principles that either overly or interface with the mining legislation. The effect the underground explosion at Moura No 2 in 1994 had on the final content of the new legislation is also considered. Health is often the neglected twin of safety and health legislation and the paper previews the health surveillance system being proposed in Queensland to ensure that health of mine and quarry workers is afforded the same priority as their safety. By increasing the structured management of occupational health problems in our mines there is an opportunity to make significant improvements in mine safety In conclusion the paper reviews the results to date since the introduction of the new mining safety and health legislation in Queensland on the 16 March 2001. Progress has been made and more is yet to be achieved

Jan 1, 2003

By Caigen Wang, Wending Ma, Xiexin Mi

The urgent need for the control of surface subsidence caused by longwall coal mining in densely populated areas of China has led to a feasibility study on the effectiveness of longwall goaf cemented backfill. The study is focussed on exploring the potential of longwall goaf cemented backfill practice for surface subsidence control. Specific backfill geometry was designed in view of the characteristics of the longwall coal mining system. Laboratory physical simulated tests were carried out with different backfill material properties and pack size. The tests achieved a marked reduction in surface subsidence by the use of goaf cemented backfill. The system has been shown to be effective in laboratory tests, the challenge now is to overcome the engineering problems to put it into practice.

Jan 1, 1998

By Gleadow AJW, Foster DA, Kohn BP, Raza A

A large and increasing data base of apatite fission track results from sedimentary and granitic rocks exposed within the southeastern highlands and along the continental margin of Australia provides constraints for the tectonic development of the southeastern passive margin. The fission track results suggest that many regions of the southeastern margin of Australia experienced distinct episodes of relatively rapid cooling during the middle Cretaceous to early Tertiary that can be attributed to the effects of rifting. One cooling episode is middle Cretaceous in age and related to denudation of the southeastern highlands from Tasmania to northern New South Wales between -90-100 Ma. Rocks exposed along the present coast line record a later episode of rapid cooling, which is diachronous and decreases in age northward from -80 to 90 Ma in northern Tasmania to southern New South Wales, -60-80 Ma in central and northern New South Wales, and to -50-60 Ma in southern Queensland.

Jan 1, 1995

By B Huls, B E. Smith, I Brake, M Yu

A brief outline of some of the pioneering events in the development of flotation technology, which originated in Broken Hill at the start of the 1900s, is presented. The development of the original Potter-Delprat process, the introduction of oils to generate froth flotation and the achievement of selective flotation processing are described, all focussed on solving challenges with the Broken Hill Pb-Ag-Zn ores. Some recent initiatives in flotation at BHP Billiton operations are also outlined, covering coal, copper, lead-silver-zinc and diamonds. Some views are offered on the characteristics of innovation in flotation and on possible trends into the future.

Jan 1, 2005

The Telfer Gold Mine, owned and operated by Newcrest Mining and located in Western Australia, is currently being expanded. A new underground sublevel cave development is proposed along with an appreciable expansion of the open pit. The Telfer area is generally subject to low rainfall, however, during the wet season cyclonic events can result in sizable rain events, which have the potential to cause substantial inflow. In addition to this, during the first five years (nominal) of the mineÆs life, there is the potential for drainage paths between the pit and the underground mine via decommissioned underground workings which lie directly under the pit. After this initial five year period the pit floor will be mined out below the old workings and will therefore no longer connect to the underground, however cave breakthrough to the surface may start to occur thus providing another water path into the underground mine. To arrive at an optimum, safe solution for dewatering the mine that successfully addressed the above items, a rigorous risk analysis was included as an integral part of the design process. This involved the determination of the probability of events occurring and the consequences of these occurrences. This was compared against the cost of mitigation for the various events. This paper outlines the process by which a safe concept addressing all the issues relating to dewatering the proposed mine has been arrived at. This process included: Establishing the pit catchment areas. These were based on historical run-off data and took into account practical mitigation works. Establishing an Average Recurrence Interval (ARI) based on reference material and historical rainfall data. Utilising a standard approach based on Australian Rainfall and Run-off (ARR) to calculate pumping and storage requirements for the various catchments. Analysing the 20 years of recorded rainfall in the Telfer area to establish the duration, magnitude and sequence of events. This analysis assisted in determining the surface run-off coefficient. Establishing potential water storage areas and determining the risks associated with using particular storage options. Establishing the percolation rate through the cave zone. A degree of uncertainty regarding the percolation rate in the cave zone required that the consequences of using various percolation rates were considered to aid in establishing the rate which was adopted. Establishing preliminary concepts and determining the most economically viable concept. Conducting a risk assessment based on the principles outlined by Australian Rainfall and Run-off (ARR) to confirm that the appropriate Average Recurrence Interval (ARI) had been selected. A risk assessment was also conducted in accordance with client requirements. Establishing the optimum pump station sizes and storage capacities. Establishing the appropriate numbers of duty and standby equipment. By using the foregoing process, which included a number of stages of risk analyses, an optimum dewatering system concept was produced.

Jan 1, 2003

By Hoberg H, Schnieder FU

The disposal of residues from coal preparation and processing will to an increasing extent require investigation and consideration of the environmental problems resulting as a consequence of this. Different authors (Diingelhoff and Plankert, 1983; Hasenpatt, 1985; Szczepanska and Twardowska, 1987) have concentrated primarily on the content and the mobilisation of inorganic contaminants such as chlorides, metals and heavy metals from spoil tips, while no publications have yet been found on the question of a possible emission of organic contaminants (PCB, PAH, HC HC) from processing residues. Here the flotation residues in particular are able to bind larger quantities of organic contaminants by physi-sorptive means because of their large specific surface and, after disposal, to be re-emitt than into the environment. The flotation agents used in coal flotation are mixtures of technical distillation products with a correspondingly fluctuating composition. As Hey, 1986 showed, they may contain, in addition to the main components (n-alkanes, alcohols, surfactants), over 50 individual trace substances. In conjunction with the structural-chemical similarity of the individual components, this complicates the quantitative analysis of individual components considerably. For the analysis of hydrocarbon content of flotation products by means of extraction with organic solvents in accordance with DIN 38408, H18, the difficulty arises, besides the insufficient sensitivity at low concentrations, that geogeonic hydrocarbons are extracted from the coal as. well and the analysis results are thus falsified. These problems were overcome by the application of the 14C radiotracer method where certain components of the flotation agents are marked with radioactive carbon (14C). By measurement of the radioactivity of solid and liquid samples, the concentration of the marked substance can be measured very sensitively and precisely, whereby the accumulative measurement of similar organic substances is ruled out. Thus the reaction path of certain substances in complex reagent mixtures such as flotation agents can be traced excellently and the conceivable environment burden resulting from flotation tailings disposal can be estimated. In this paper, the adsorption behaviour of typical components of coal flotation agents are investigated for different coals and types of gangue material, the reagent content of flotation concentrates and tailings, as well as the mobility of the reagents adsorbed onto solids. The knowledge of adsorption and desorption mechanisms of unpolar hydrocarbons emulsified in water to solids are also of particular interest for the understanding of processes of organic soil contamination and for the further development of washing processes for oil-contaminated soils.

Jan 1, 1993

Shortly after the outbreak of war in September, 1939, it became apparent that considerable quantities of certain metals and alloys which at that time were not being produced in Australia would be required in increasing amounts for the prosecution of the war effort.Australian industry had relied on overseas sources of supply for the relatively small quantities of many special metals which were needed under peacetime conditions. As the war progressed so great became the demand for mooy of these alloys in Great Britain and other allied countries that it was necessary for them to place an embargo on the export of these materials, and thus it soon became evident that if Australia's production of munitions was to expand and develop it would be necessary for her to become independent of overseas sources for many of these essential 'items. The shipping position also became very acute, and this, accentuated the difficulties of obtaining these alloys. Because of the conditions outlined aqove, the manufacture of over thirty different metals and alloys .was undertaken at Newcastle during the past decade. It is with two of these that this paper proposes to deal. They are tungsten powder and ferro-silicon.TUNGSTEN POWDERTungsten is a rare and comparatively new metal. It is used extensively in the production of high speed tool steel, some grades of which contain up to 22% tungsten. Such articles as twist drills, reamers, milling cutters, and lathe tools are made from tool steel, and the demand for these during the war years was greater than ever before. The use of tungsten in the manufacture of high speed steel was first developed in 1914 by the Germans, and when it was discovered that they were using tungsten bearing steel for the production of munitions there began a world-wide search for ores of this rare metal.

Jan 1, 1947

By B McIntosh

Sustainability in its simplest assessment has been defined as æmeeting the needs of the present without jeopardising the needs of future generationsÆ. For the mining industry alone, this statement could indeed be interpreted by the many cynics in our community as an oxymoron; as miningÆs very existence requires the extraction and consumption of finite resources. However for the future of industry as a whole, the integration of mining, minerals processing and manufacturing presents us with a unique opportunity to achieve sustainability through the continued supply of metals and materials for society, in a manner which can achieve positive social outcomes through a triple bottom line approach.The Kwinana Industrial Area has been Western AustraliaÆs premier heavy industrial precinct for more than 40 years and its prevailing level of prosperity will ensure it remains a significant contributor to the State economy through the 21st century.The Kwinana industries depend on each other for the production of essential raw materials vital to their manufacturing and refining process, an innovation that also has significant environmental benefits.Formed in 1991, the Kwinana Industries Council strives to foster positive interaction between member companies and with the local community.The aims are:to co-ordinate the activities of Kwinana industries on a range of common issues; provide effective liaison with the local community; promote a positive image of Kwinana industries; highlight contributions to the community by Kwinana industries; and work towards the long-term viability of the Kwinana Industrial Area. The Kwinana Industries Council facilities these aims by focusing on developing and employing leading edge technology, giving workplace health, safety and environment top priority, and taking a committed, responsible and pro-active approach to environmental protection, whilst forging a two-way partnership with the local community.The sustainability of industry is the key objective for the Kwinana Industries Council and through the involvement of the 13 member companies industry strives to:achieve efficient processing of resources to provide a range of goods and services needed by the community; achieve acceptable and decreasing level of environmental impact; provide jobs and income for our community; and engage co-operative projects that benefit the local communities, the State and Australia.

Jan 1, 2004

The distribution of p(~rphyt1 copper deposits, in time as well as place, is used to propose an occurrence model based on the genesis models of Sillitoe and Rona. A magmatic source of the metals is accepted. The characteristic metallogenic epoch and the migration of the mineralization event along an elongate metal province are explained as the result of subduction of an obliquely- oriented strip of mineral-enriched material on the oceanic plate. Two mineral-enriched trails emanate from a hot-spot source of high-intensity hydrothermal activity in an oceanic rift. Because the whole plate system moves relative to hot spots, the hydrothermal source appears to migrate along the rift, and the two trails are not parallel to transform faults, but form a broad "V" centred on the hotspot. Source loci are spaced at intervals of about 3000 km, resulting in the possible repetition of metallogenic epochs, in a subduction zone province, at about 100 m.y. intervals. The position of the mineral-enriched strip can be found graphically, given ages of a series of deposits in a province, and the plate convergence vectors. This knowledge provides an exploration tool at regional scale and, by reflection across the rift, the potential for exploration is extended across oceans. The model has implications for commodities and deposit types other than porphyry coppers.

Jan 1, 1987

By N S. Rauert

The Barrick Gold Granny Smith underground operation located at the Wallaby deposit is currently in a transition period from a near surface operation in ramp up mode to a fully operational deep mining operation with annual production exceeding 1 Mt/a. A key element in this process has been the project execution of the Wallaby Deeps project from initial scoping study in 2007 to the major production component of the Wallaby operation by 2013.The Wallaby Deeps project serves as an example of how an ongoing detailed study program can be integrated into a day to day mining operation assessing risk and mining application in a perceived challenging narrow vein geotechnical environment prior to mining. A detailed study phase to feasibility level is carried out prior to the mining each zone of Wallaby with mining approval only granted on study completion with full justification.A central element in this process is an optimisation study that utilising the Mineable Shape Optimiser (MSO) and Schedule Optimisation Tool (SOT) software tools developed by AMIRA Ltd PRIMO research project is used to carry out an NPV value based option study. This optimisation process being then tempered to reality by a predefined practicality assessment process utilising extensive peer review by operational and study team members as well as industry experts.Other challenges facing the Wallaby Deeps project include the requirement to maintain the ramp up production profile to full production by 2012 without disruption but with pressures of an ongoing geological resource to reserve conversion program essential for the study process and mining approvals and also development rate achievement.To date these challenges are being met with integrated planning and the value of the study program itself. Production in 2012 year to date is well on the way to annual production rate exceeding 1 Mt/a.CITATION:Rauert, N S, 2012. Wallaby Deeps - from the optimal opportunity to reality, in Proceedings Narrow Vein Mining 2012 , pp 207-214 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012

By M J. Sale

The Epithermal and Mesothermal Gold Prospectivity Modelling Projects recently completed by Crown Minerals provided explorers in New Zealand with a new compilation of historical exploration data combined with new geological information from the GNS QMap 1:250 000 scale mapping project. These data were used to produce predictive mineral potential maps for gold mineralisation in New Zealand. The aim of these projects, which was to stimulate mineral exploration and investment in exploration, has been successful with new companies acquiring new tenements and committing significant exploration expenditure to exploring in New Zealand in the coming years. The projects were undertaken at a national scale and consequently not all exploration data were compiled into the prospectivity models. HPD New Zealand Ltd recognised the value of the prospectivity modeling work and committed exploration funds to continue the modelling process started by the projects. They recognised the need to compile the remaining data and run the models again to allow detailed exploration targeting.

Jan 1, 2004

Since the mid-1970s there has been increasing attention in the South Pacific area to the problems of disaster planning and management at various levels, mainly from regional through national to provincial levels. This concern has been expressed in a variety of ways. International aid donors have made their views known in commentaries or reports. Seminar discussions have been organised at the regional level (such as at Suva, 1976; Suva, 1979; Tonga, 1982 and Suva, 1983). In-country training workshops or meetings have been organised (such as the "Disaster Preparedness Workshops for Non-governmental Organisations" in Pacific countries, jointly run by the Australian Red Cross and the Australian Overseas Disaster Response Organisation and supported by AIDAB, in Vanuatu, 1985; Solomon Islands, 1985; Western Samoa, 1986; Fiji, 1987; Tonga, 1987; Lae and Port Moresby, Papua New Guinea, 1988) or held outside the area (ACDC at Macedon, 1981). Training and/or research institutions have been established such as the East-West Center, Honolulu, and the Asian Disaster Preparedness Center, Bangkok (more Asia oriented). As part of the East-West Center Pacific Islands Development Program's Disaster Preparedness Project, a detailed manual of disaster preparedness and response procedures and guidelines has been published (Carter, 1984).Table 1 and figure 1 show that the area with which this discussion deals is a highly fragmented island region, comprising many small, some minute, nations, both in land area and population. The social structure is predominantly rural, with the capital city often making up a small part of the total population and, in absolute terms, little more than a small town. Outside the administrative and governmental activities concentrated in the capitals, in most cases the indigenous inhabitants depend on subsistence agriculture or on usually a monocultural concentration on a cash crop, most frequently coconuts.

Jan 1, 1990

The purpose of this paper is to present a detailed account of the development of the Blasthole Diamond Drilling method of stoping now used at the property of Big Bell Mines Limited, in Western Australia.The ore body is one of the large low grade gold deposits of this State, being a continuous lens 1,850 ft. long and ranging in width from 15 ft. at the ends to 120 ft. at the widest part, the average width being 59 ft. It was first worked in 1913 by a local syndicate, and up to 1924, when operations ceased, 64,448 tons of 3.4 dwt. ore were mined from a shallow open cut. Between 1928 and 1932, 15 deep diamond drill holes were put down to test the ore body at vertical depths ranging from 100 to 700 ft. On the information gained from these drill holes, Premier Gold Mining Co. Ltd. began underground explQration. A level was driven at a depth of 253 ft. and crosscuts put out to the full width of the, orebody at intervals of 100 ft. along the strike, all ore broken being put through a sampling plant. On completion of this sampling,' Big Bell Mines Limited was formed as the operating company, and a plant with a capacity of 1,000 long tons per day was erected and mining and milling operations were commenced in 1937. Ore was first mined from glory hole stopes, 65 ft. long, separated by 35 ft. pillars, by benching using conventional steel with changes up to 20 ft., all broken ore being hauled to the main shaft on the...

Jan 1, 1948

By Linying W

Entropy is an important concept both in natural and social sciences.Considering the preparatory process of the earthquakes as an open system, in view of basic ideas of the Theory of the Dissipative Structure, the seis-mological Entropy is introduced as an order parame-ter, describing the scale of order associated with the earthquake distribution in time, space and mag-nitude. The features of evolution of seismic acti-vities before and after the large earthquakes have been studied by using the seismological entropy.The preliminary results show that the seismological entropy in certain region decreases as the large earthquake is approaching, it means that the distri-bution of earthquakes has turned gradually in order from disorder.It is expectation that the application of the Principle of Entropy in seismological research will deepen the understanding of the physical process of earthquake preparation. Meanwhile, it will also offer some enlightements in studying mitigation of seismic hazard as well as earthquake prediction.

Jan 1, 1990

By Partridge AC

In order to provide a'valid description of the performance of size classifying equipment it is necessary that a standard procedure be established for testing and for the subsequent expression of results. Such a standard would permit the valid comparison of alternative equipment and may provide a basis for the prediction of performance. An Australian Standard (AS 1634-1974) has been used as the starting point for an International Standards Organisation-(ISO) working group (of which the authors are members) charged with the preparation of an ISO Standard for the expression and presentation of the results of tests on coal size classifying equipment. The approach taken is applicable to all types of sizing equipment (cyclones, screens, dedusters, etc.) and should be suitable for adoption in the minerals industry as well as by coal preparation engineers. The background to the proposed Standard, is given,including a critical review of other frequently quoted performance measures, the procedures described in the draft are discussed, and an example given.

Jan 1, 1984