Search Documents

The paper considers Aboriginal responses to large-scale mining, including Indigenous attitudes towards land access for exploration and project development. The core question, in which I have been interested for some time (Trigger 1997a; 2000; 2001), is: what are the significant factors affecting responses among Indigenous communities to mining exploration and development project proposals?

Jan 1, 2002

A predicted increase in aluminium production and the possibility of a diminishing supply of petroleum coke for anode electrodes in alumina reduction cells makes it desirable to find alternative electrode materials. Browncoal char, with a lower ash content and with an elemental purity similar to petroleum coke, was produced by leaching in hydrochloric acid, washing with water, and charring at 1,150°C. The cost of processing is estimated tobe competitive with petroleum coke.Without further processing the bulk density and real density were undesirably low, but by briquetting the coal before charring and crushing, the bulk density was improved to 92 per cent of the petroleum coke value andthe particle density was improved to 92 per cent of the density of petroleum coke by water displacement or 75 per cent by mercury displacement.Pre-baked electrodes were prepared from the char alone, mixtures of petroleum coke and char, and from petroleum coke alone, all bonded with coal tar pitch.The electrodes were tested for the usual physical properties and were evaluated for performance in a laboratory size alumina reduction cell.Electrodes based on brown coal char alone were found to be inferior in physical properties and performance, but mixtures of the char and petroleum coke, despite poorer density, electrical resistivity, and carbon consumptionon a theoretical basis, in performance tests gave up to 17 per cent better carbon consumption per weight of aluminium produced and 21 per cent better electrical current efficiency than the electrodes based on petroleum,coke alone.It is suggested that larger scale tests are warranted.

Jan 1, 1971

By D R. Cohen

As one of the four basic sciences, the study of geology is intrinsically worthy as a means of increasing fundamental knowledge of the behaviour and evolution of the universe. Geological knowledge can also be translated into practical outcomes for society such as resource discovery and protection of the environment. Australia has a long tradition of providing very high quality geoscience programs to prepare graduates for a range of occupations. We are, however, reaching a nexus in the way universities should or can deliver engaging programs. This has been triggered by the rapid evolution of the digital world (the Internet of Things), new technologies, unprecedented access to information, better understanding of the processes by which we learn and adapt our thinking, growing complexity in the problems we must face or opportunities to grasp, and university funding models. Designing education programs for the next generation of geologists extends far beyond tinkering with syllabuses. We must develop skills sets that will allow graduates to work in rapidly changing landscapes, but in doing so may have to sacrifice content to build capability in our graduates. Whereas universities must respond to changing demands on graduates by ensuring degree programs contain an appropriate balance of material and high quality of delivery, industry and government must also fulfil their responsibilities to provide additional training programs for graduates to assist their rapid transition into independent professionals. This paper examines various educational issues being considered in developing the new Decadal Plan for the Earth Sciences, and reflects on directions that education is heading in many of our universities.CITATION:Cohen, D R, 2017. Educating the next generation of geologists, in Proceedings Tenth International Mining Geology Conference 2017, pp 3–10 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By Pfeifer H. C, Nicacio P. A D

Sinter has been used as part of the metallic charge in large-scale blast furnaces for many years with the well-known benefits in terms of productivity and fuel consumption. However, because of the high investment in a conventional sinter plant, small blast furnaces and the associated integrated mini steel plants have not taken the advantages of using sinter. Recently KTS Korf Tecnologia Siderurgica, a division of Mannesmann Demag Ltda in Brazil, has developed a mini sinter plant for which the investment is compatible with small blast furnaces. Consequently, it is of great interest to evaluate the economical impact of using sinter in such small-scale integrated steel plants. In order to compare two alternatives, ie 100 per cent ore and 70 per cent sinter in the blast furnace burden, mass and heat balances for the entire operation from sinter plant through the blast furnace and EOF-based melting shop, were performed to evaluate the final production cost of the liquid steel. It was found that, depending on the sinter feed price, substantial savings can be obtained with the use of sinter.

Jan 1, 1999

Mine ore, reduced to minus 71/2 in. by primary crushers, is stockpiled. Size reduction of the reclaimed material by secondary and tertiary crushers is achieved in a closed circuit crushing and screening plant. Screen products of minus 30 mm plus 6 mm lump, and minus 6 mm fines are stockpiled by conveyor and stacker systems prior to rail despatch 10 port facilities at Dampier. Crusher settings, determined from experience, are closely maintained to obtain the desired lump/fines ratio. Chemical and sizing analyses from automatically taken samples are used to maintain product specifications. The beneficiation plant upgrades the fines product when this is necessary. The recorded wear life of individual plant components is the basis of a planned maintenance programme.

Jan 1, 1970

Research on the Design and Processing Characteristics of 320 m3 Air-Forced Mechanical Flotation Cell

Sep 13, 2010

By R Aseervatham

The fast tracked mine development strategy attempts to blend feasibility studies and engineering/commissioning functions into a streamlined process. In this compressed process, environmental issues are difficult to control with respect to the optimisation of operational environmental performance. This paper presents a standard mine development process with specific focus on environmental issues, and contrasts this against Rio TintoÆs recent fast track experiences on the Hail Creek project (Australia), the Baranj project (India) and the Gokwe North project (Zimbabwe).

Jan 1, 1999

By J R. Goff, R Carver, D S. Sheppard

The REGCHEM (Regional Exploration Geochemistry) stream sediment geochemistry database of open file mining company data, managed by GNS Science, was recently made accessible via the internet (http://maps.gns.cri.nz/website/minmap/). REGCHEM provides coverage of selected elements in mineral rich areas of New Zealand. Analysis of REGCHEM data highlights problems with inconsistencies between different surveys in terms of sampling methods, number and types of elements analysed, analytical techniques and detection limits. New, consistent multi-element geochemical surveys with national coverage are required. To test sampling, analytical and data treatment techniques for the new surveys, a pilot stream sediment geochemical survey was carried out in the Thames area, Hauraki Goldfield. Seventy samples were collected in an area of 220 km2 representing about one sample every 3 km2. The samples were analysed for 50 elements, mostly by XRF.   Regional patterns are apparent in the concentrations of some elements. Several elements, such as As, Cd, Cu, K, Pb, Sb, Se, and Zn exhibit anomalous concentrations mainly in the western part of the study area, related to Au-Ag-Zn-Pb-Cu epithermal quartz veins and porphyry Cu occurrences in hydrothermally altered andesitic terrane.   Mercury is anomalous in southern samples, reflecting cinnabar occurrences in the Kauaeranga valley (eg Mangakirikiri), and the occurrence of cinnabar as a late stage mineral in some of the Thames epithermal veins. Ba and U are anomalous in the eastern samples, and these anomalies are probably related to the presence of rhyolitic rocks in the eastern part of the project area.

Jan 1, 2006

The methods and equipment developed and used at the Mount Isa mine to obtain samples of uncemented hydraulic fill lying above major horizontal pillars are described. From existing underground development, samples were obtained at distances up to 50 m, of which up to 30 m was through hard rock. Samples were used to predict fill behaviour as it affected mining security during recovery of the pillars.Specialized equipment for difficult sampling situations and also other sampling exercises are described.

Jan 1, 1976

WMC was a late entrant into Indonesia in mid-1996, but had considerable experience and success in exploring in Asia, particularly the Philippines since 1988. Given the geological similarities to the Philippines and IndonesiaÆs superior æcradle to graveÆ Contract of Work (CoW) tenure system, the entry into Indonesia was a logical decision but nonetheless a result of detailed planning. At the time of WMCÆs entry, Busang in Kalimantan was still a 60 moz wonder and the euphoria of this apparent discovery had overflowed into every aspect of exploration. Many junior mining companies and tenement speculators were clamouring for properties in Kalimantan, whilst other serious and capable explorers had to compete for properties and exploration personnel in an era of high and often unrealistic expectations. The picture in late-1998 and through 1999 is dramatically different, as the worldwide downturn in the price of most metals coincides with financial and social crises throughout most Asian countries. The impact of this has been particularly severe in Indonesia and when coupled with the negative sentiment of the Busang fraud has resulted in an exodus of junior companies and also some of the majors. This is understandable given the much publicised social unrest, uncertainty of government, mooted changes to the eighth generation CoW, increasing illegal mining and heightened community expectations. The reality however is somewhat different and although clearly a crisis in many respects, it is also a time of great opportunity.

Jan 1, 1999

The No. 2 Ore-shaft, at Mount Isa Mines Limited, involving the use of boreholes as ropeways for the upper portion thereof, constitutes, we believe, a unique feature in hoisting installations. The boreholes were sunk from the surface to a depth of 390 ft., thus eliminating the necessity of erecting the hoist at an underground location or construction of the shaft for this distance. Fig. 1, a diagrammatic cross-section through the shaft, shows the complete installation from the surface down to the first loading station below No. 7 haulage level.During the latter part of 1936, conditions encountered in sinking the Main Ore shaft made it impracticable and uneconomical to continue deepening it to serve haulage levels below the present No. 5-level. Plans were therefore made for an interior shaft, to serve new lower levels, that terminated above No. 5-level so that ore hoisted could be drawn off on this level and transported to the Main Ore shaft for final conveyance to the mill crude ore bin.Referring again to Fig. 1, it is apparent that the section above No. 4-level, if opened out to full shaft size, would be inoperative and would serve no useful purpose except, possibly, as a ventilation duct. Original plans therefore did not include continuation of the shaft above No. 4-level. Excavation of a hoist room upon No. 5-level; erection of sheave wheels just below No. 4-level, and a long inclined ropeway leading from the hoist to the sheaves, were incorporated in the general layout. Work on the lower sectionof the shaft had started when the idea of locating the hoist...

Jan 1, 1939

Application of the Anaconda Simplified Work Index for Multiple Test Sizes Vale uses Bond Work Index measurements extensively in a number of applications. The Bond Work Index is usually a good parameter for checking scale up procedures when sizing ball mills, as well as the basis for variability analysis whenever drill core data is available. It is typical to measure between 100 and 150 Bond Work Indexes, depending on the deposit characteristics. The Bond procedure is relatively complex and time costly. It also requires relatively large amounts of sample, which are very expensive to be obtained. The benefits of the Anaconda simplified procedure are: considerably smaller sample requirements and laboratory time. This makes it very much attractive at Vale's development centre, including geometallurgical mapping, operation efficiency control, mine to mill, etc. The Anaconda simplified procedure was implemented and evaluated at Vale's Development Centre using a number of ores and several samples of each ore totalling more than 190 measurements. The Anaconda simplified method was calibrated for several test sieves and a correlation for any test size was determined for Vale's test mill. The calibration was also extended for two sample top sizes. The relative error of the simplified procedure was found to be in the range of nine per cent which is within the expected error Bond standard procedure. The implementation of the Anaconda method at Vale's development center has been used with great success over the past years in several green field, brown field projects and operating plants.

Sep 13, 2010

By Edwards A. B

The following note on the mineral association in the ores of the Tennant Creek Goldfield, Northern Territory, is largely based on Mineragraphic Reports Nos. 49, 89, 117 and 193 of the Council for Scientific and Industrial Research. These reports are the results of the examinations of auriferous specimens from a number of mines of the goldfield and are now supplemented by the examination of further specimens from Mt. Samuel forwarded by Mr. V. G. Martin.The Tennant Creek Goldfield lies in the central portion of the Northern Territory, about Lat. 190 35', Long. 1340 15', on the Overland Telegraph Line and about 369 miles north of Alice Springs. It comprise an area extending about 50 miles east and west, by 30 miles north and south.The geology of the goldfield has been described by Woolnough. (2)The rocks of the area are of pre-Cambrian age, and consist of talcose, chloritic, micaceous and siliceous schists of sedimentary origin, interbedded with flows or dykes of schistose quartz porphyry, and of granites which were intruded subsequent to the regional metarporphism of the area. The rocks are moderately folded, but the beclding tends to be obscured by a pronounced east-west cleavage. The most continuous orebodies run east and west, parallel with this cleavage.Numerous lenses of hematite occur in the schists, with their long axes, parallel to the cleavage, and the gold values of the field are frequently associated with such hematite bodies. The dimensions of these hematite bodies are variable but rarely exceed a length of 300 ft., with an average thickness between 10 and 30 ft.; the original vertical dimensions are thought to be comparable with their length. The lenses tend to occur in groups when they are arranged en echelon both horizontally and in depth; and erosion has exposed individual lenses to different degrees, ranging from incipient exposure to complete removal. The existence of unexposed hematite lenses at depth has been proved by geophysical surveys, coupled with drilling tests. (3)A few of the bodies are pipe-like. Many are surrounded by a casing of brecciated rock, composed of fragments of hematite and shattered country rock, and presumably caused by subsequent earth movements which crushed the country rock against the resistant hematite bodies. In the early days of the field most of the important gold occurences were found within these crushed zones, or, to a less extent, within the hematite bodies themselves.These occurrences appeared to be associated only with those hematite lenses which were intersected by quartz veins or other lines of weakness, of later origin than the crushing. This led Woolnough to think that the introduction of the gold and attendant bismuth was subsequent to the...

Jan 1, 1942

By S H. Begg

There is strong evidence that many major oil and gas (O&G) projects are plagued by large cost and schedule overruns, or significant underperformance in productivity. Similar evidence exists for large mining projects. This paper claims that uncertainty is the underlying reason why projects fail to deliver the metrics used to justify their investment, or to deliver the economic value possible if alternative decisions had been made.Most technical and economic analyses are performed to reduce uncertainty to help make decisions. Decision-making is about ranking alternatives and choosing the best; rarely are precise predictions required, if this is even possible. Better uncertainty assessment is one of the keys to better decisions, thus better business outcomes. To get better decisions it is suggested that the focus or reward/penalty incentives be shifted away from the quality of outcomes to the quality of decisions. High-quality decisions are those that are generated from the skilled use of the tools, methodologies and processes from the discipline of decision analysis.Uncertainty is quantified by probability, which is a degree of belief in the truth/falsity of some proposition about a quantity relevant to a decision, such as volume of in-place resource, future price or action of a competitor. The probability a person ascribes to a proposition depends upon their information set; hence probability is subjective – it is not an inherent attribute of the quantity of interest or the physical system.The above simple observations have profound implications for modelling approaches, how they deal with uncertainty, the use of data to help assess uncertainty and the reliability of information provided by subject-matter experts. The limited circumstances under which frequency data (from spatial or temporal variables) can be used to assign probabilities is also reviewed.People, in general, are subject to a range of biases and cognitive errors. Research with O&G subject-matter experts shows that their expertise offers little or no protection from making errors in probability assessments and other judgements.CITATION:Begg, S H, 2016. Decisions, decisions – uncertainty, variability, modelling and psychology, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 9–18 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By W T. Yen

Pyrrhotite crystallises as either a hexagonal or monoclinic structure, both of which can occur in ore deposits. In general, pyrrhotite is not considered as a valuable mineral unless it contains considerable amounts of other metals like nickel or copper. In fact it causes numerous problems in flotation including intensive oxygen consumption, which results in poor selectivity among sulphide minerals in the processing of complex sulphide ores. Also, because of its high sulphur content, pyrrhotite is a major contributor to environmentally detrimental sulphur dioxide (SO2) emissions from smelters. Pyrrhotite also interacts galvanically with grinding media via electrolyte species present in the flotation pulp, resulting in media corrosion. The most effective way to reject pyrrhotite is through a separation stage, which may be difficult when both types of pyrrhotite are present in the ore. In this regard depression of pyrrhotite through a flotation stage may be applied. Pyrrhotite depression by either intensive oxidation or by using sodium cyanide has been practiced. Results present in this work show that NaCN can depress pyrrhotite effectively when combined with an alkaline environment and low collector concentrations.

Jan 1, 2002

Incorrect sampling and measurement operations and misunderstanding the components of variability can cause huge economic losses to the mining industry. The main objective of this paper is to illustrate by means of four historical facts how Codelco has been evolving in those issues since the late 1980s. The El Abra bias, the awareness of the different kind of sampling errors and the role of Francis Pitard, the awareness of weighting errors, and the understanding of the components of nature and process variability are described. It has been a slow but a consistent process. Much progress has been achieved but still there are many opportunities for improvement to transit from the tonnage culture to the productivity culture.

Jan 1, 2008

By L J. Ingle, K L. McPhee, A G. Hunt

Iron Road Limited (IRD) is currently developing the Central Eyre Iron Project (CEIP) at Warramboo on the Eyre Peninsula, South Australia. The project consists of a 30 year open pit mine, magnetite processing facilities, standard-gauge railway and deep water, Cape class capable port. Major South Australian government approvals have been received and funding arrangements confirmed.The 4.5 Bt Mineral Resource (3.7 Bt Ore Reserve), the largest in Australia and among the largest globally, is to be mined to produce 24 Mt/a high-grade, 67 per cent Fe, magnetite concentrate. This in-demand, premium product has a P80 of ~100 µm, suitable for both direct sinter feed and an additive in pelletising.The extensively drilled, homogeneous orebody is unique in both geology and mineralogy; only averaging 15 per cent Fe yet coarse-grained with almost negligible phosphorus and sulfur content. This has allowed significant opportunities to tailor the mining method to the orebody, utilising both optimised blasting as first stage comminution, as well as in-pit crushing and conveying (IPCC) to reduce the heavy haulage diesel fleet and optimise the pit shell.Approximately 1 Mt/d of total material, ore and waste, is required to be moved from the pit daily, introducing materials handling challenges, overcome by a flexible IPCC set-up, multiple overland conveyors and an exacting mine plan. Non-conventional waste and tailings storage is utilised to allow for significant water savings, progressive rehabilitation and minimisation of land impact.The processing facilities utilise both the magnetic and density properties of the magnetite to beneficiate the ore. The coarse-grained nature of the ore is exploited to minimise comminution yet still liberate a high quality product. Utilisation of modular construction methods allows risk reduction during construction and reduced pumping requirements during operation.This paper highlights the uniqueness of the CEIP, with focus on the mineralisation of the orebody, and the beneficial impacts this has on both the proposed mining method and processing. Magnetite mining is not new and IRD has used the learnings of others, and input from various vendors and industry experts, utilising knowledge and expertise to engineer an innovative, yet supported, project design.CITATION:McPhee, K L, Hunt, A G and Ingle, L J, 2017. The Central Eyre Iron Project – developing a new iron ore mine in a challenging climate, in Proceedings Iron Ore 2017, pp 613–620 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Lonie W. M

The rapid development of the Australian steel industry over the past twenty years has greatly increased the demand for coking coal from the collieries owned by the Broken Hill Proprietary Co. Ltd. and Australian Iron & Steel Ltd. This in turn has called for an intensive and continuous programme of colliery expansion and new colliery development, along with the reorganization and modernization of existing collieries.This paper presents a general description of the factors involved and the techniques used in planning modern colliery development for the steel industry.PRELIMINARY GEOLOGICAL INVESTIGATIONSIn any colliery development, preliminary geological investigations require a detailed and practical knowledge of the geology and characteristics of the coal-field as a whole. In the early stages of the investigations, probably the most valuable information is obtained from outside the particular area under review, rather than within it, and unless the geology of the coal-field is understood, the projection of the known information into the unknown area cannot be carried out with certainty.Because development of the coal seams from the outcrops has been an apparently simple matter and not subject to the risks involved in deep mine development, the geology of the New South Wales. coal-fields has not received the attention that major mineral resources warrant.Only the most accessible regions of the coal measures have been generally prospected, while the potential areas remain...

Jan 1, 1957

GOOD ventilation is recognized as an essential for the preservation of health, and laws have accordingly been framed in many countries for the provision of adequate ventilation in factories and places of public resort as well as in mines.Apart from the legislative enforcement of hygienic measures as a matter of public 'policy, the ventilation of mines has an important economic aspect, since it affects to a large extent the industrial efficiency of the workmen, and consequently the cost of mineral production. Until recent years the ventilation of metal mines has not generally received much consideration, and the importance of pure air has been sometimes overlooked. To the absence of explosive gases in such mines, and to the cost of the installation and working of mechanical ventilators, may generally be attributed disregard of adequate ventilation. In this paper it is not proposed to furnish statistics on the mortality and morbidity of miners, or a treatise on the medical aspect of the rock-dust problem, to further elaborate which would be superfluous, the deleterious effects of the latter having been...

Jan 1, 1912

Further evidence is presented as to the widespread occurrence of Thiobacillus ferrooxidans in nature in association with sulphide minerals. Leaching rates are discussed in terms of the effect of environmental parameters, particularly Eh and pH, on the bacterial process.The methods used to investigate leaching phenomena are described and the advantages and limitations of each method are discussed. A theoretical treatment of the bacterial leaching process is given which indicates that the optimum conditions arrived at by traditional methods are compatible with those deduced from consideration of the mathematics of continuous culture and thermodynamics

Jan 1, 1968