Search Documents

Design and construction techniques used to develop two highway tunnels in inaccessible mountainous terrain are described. Measures used to adapt the design to the unusual geology and topography are discussed, as well as measures to adapt the construction methods to available equipment, materials, and skills. Sharp local variations in geoloqic conditions resulted in field modifications to both design and construction techniques. The geology is a volcanic ash and breccia-agglomerate at one site, a jointed andesite at the other, which is also the site of a major landslide. Both rock reinforcement in the form of pretensioned and grouted rock bolts with a shotcrete lining,and rock support by struc- tural steel sets with a reinforced concrete lining were used. A canyonside location and high lateral in-situ stresses required modification of design procedures. Pilot tunnels at both sites resulted in adapting the designs to site conditions with large savings in lining costs, disclosing problem areas in advance of the main excavation, and cushioning of blasting pressure to minimize stability problems.

Jan 1, 1976

The success of any industry depends on the planned integration of the policies and resources of the key components of the Australian economic and political structure - government, industry management, education, research, and the human resources of the industry. The Australian Mineral Industry, like Australia itself, has grown and developed at a rate not foreseen by many of our founding fathers and early industry leaders. Hence, now, as we approach the 21st Century, we need to re-think our approach to the significant new problems that are beginning to face both government and the Mineral Industry. Government initiatives, government information and support services, industry re-structuring, and research and development support, need to be carefully re-evaluated, re-diredted,. and strengthened, so that government, the community, and the Mineral Industry produce and receive the optimum education and research strategies and services. The support of academics and researchers, the development of facilities, and the design of new Courses for the future successful and beneficial exploitation of minerals need particular consideration.

Jan 1, 1986

By A Roseman, T Gruber

Traditional methods for installing gaskets for segmented bored tunnels have relied upon different bonding procedures with adhesives that carry a series of disadvantages to segment producers. Fixation of the gaskets into the concrete segment as part of the casting procedure has been developed over the last 20 years and has emerged as an economical solution to produce high-quality tunnel segments for various technical tunnel applications. This paper investigates the advantages of using anchored gaskets, the different tunnel systems that employ anchor gaskets and reviews the first anchor gasket project; the Lee Tunnel and analyses how segment production efficiencies are gained.CITATION:Gruber, T and Roseman, A, 2014. Use of anchored gaskets in segmented bored tunnels, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 253–256 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

A real Dorothy Dix title has been selec- ted for this paper. It has the advantage, however, of being capable of being interpreted in many different ways and hence I can select my own approach. You probably are thinking that this topic would be more appropriately handled by an Accountant. I wish to make it clear at the outset that I am not skilled in the sometimes mysterious ways of Accountants - likewise that profession frequently has difficulty in pinning down economists. We have our own strange ideas about profits, marginal efficiencies, cost/benefit analysis etc. What follows is in the main a mixture of two disciplines, probably in a form that few of the purists from either side would accept. Nor do I expect the reader to accept my own prejudices. The paper is designed to stimulate thought and discussion'on the subject. Emotive words such as "profit" and "loss" make for wide differences of opinion. At the time of writing there is a surprising degree of acceptance of the viewpoint that profits in Australia are too low and one is tempted to make this point of near agreement a starting Point.

Jan 1, 1975

By S Serp, M Duchateau, P Chevreux

Molten salt reactor (MSR) is a promising advanced reactor system aiming to the transmutation of minor actinides such as americium in order to reduce the inventory of ultimate nuclear waste. The fuel is a molten salt in which actinides are homogeneously dissolved in the liquid phase. A chloride salt may be retained for this concept, as it provides low melting point, high solubility of actinides, harder neutron spectrum. To avoid corrosion and precipitation issues, molten salt composition has to be carefully controlled with impurity content as low as possible. Obtaining pure actinide chlorides without contaminants such as oxide, oxychloride, hydroxide and water is still a challenge. To prepare actinide-bearing salt, the chlorination of actinides oxides was investigated in an unstirred reactor under flowing gas as solid-gas reaction. The carbochlorination of PuO2 were performed in the temperature range of 600 to 800°C with chlorine gas as a chlorinating agent and the presence of solid carbon. PuCl3 was successfully synthesised by this method and characterised by X-ray diffraction measurements but some impurities such as oxide phase remain inside the formed product. Refinements of anhydrous and hydrated PuCl3 phases by Le Bail method were also performed for crystalline materials definition. Conversion mainly depends on the chlorinating temperature and the contact between the oxide and the chlorinating agent. A conversion value of 70–80 per cent was achieved at 700°C from PuO2 with quite high specific surface area. The conversion rate was not improved with increasing the chlorination time. The volatilisation of Pu was observed during the carbochlorination experiments. To avoid a loss of Pu caused by sublimation, the chlorination temperature should be limited to 650°C despite that the conversion of PuO2 to PuCl3 was enhanced by increasing temperature. Both carbochlorination and hydrochlorination of AmO2 were also carried out leading to the formation of AmCl3. These first results suggest that americium oxide was chlorinated more readily than plutonium oxide. The purity of produced PuCl3 and AmCl3 still deserves further investigations.

Jun 19, 2024

There are still vast areas of Australia in which either the hydrocarbon potential has already been indicated but from which no hydrocarbons have been produced or else are completely untested. Despite the lack of recent new oil discoveries, it is anticipated that initial gas discoveries in these areas will be followed by oil discoveries as has happened historically. General exploration activities are continually providing new information that is being input to update previous hydrocarbon assessments for Australia, and all indications are that future exploration efforts will discover a lot of gas, some small oil pools and there is a chance to prove a major new oil province. Because of this, it is anticipated that reserves growth will continue at the average historical rate of about 200 MMB/year until the year 2000. The most frequent scenario will be costly exploration resulting in small oil discoveries and high development costs. This, in the past, has resulted in low profitability for Australian oil exploration, but windfalls for the Australian government.

Jan 1, 1981

Coal washery wastes comprise tailings, finer than 0.5 to 0.1 mm depending on the sophistication of the washery, and coarse reject, typically finer than 50 mm. Subaerial disposal of coal tailings slurry at about 30 per cent solids by mass results in the formation of a delta with an average slope of about 1 in 100, representing one extreme. The ravelling of coarse reject on loose-dumping, results in an angle of repose slope with an angle of about 37o (1 in 1.3), representing the other extreme. The pumped co-disposal of coal tailings and coarse reject results in the formation of an upper delta with an average slope of about to one in ten, between the two extremes. The depositional behaviour of these three waste streams is discussed and compared in this paper. The important depositional and material parameters, and a theoretical description of the processes involved, are also presented. Comparisons are made between the depositional behaviour of the various coal washery waste streams, and natural depositional systems, such as rivers, alluvial fans, and scree slopes.

Jan 1, 1998

By J T. Woodcock

This paper discusses characterisation techniques that can be applied to complex waste products from metal production and processing operations with the aim of devising treatment methods for upgrading the metal content for recycling. Two waste streams were selected to illustrate the role of characterisation in adapting mineral processing techniques to provide an effective recycling strategy. Waste products chosen were:aluminium dross, which contains metallic aluminium particles in a coarse matrix of many components; and steel shredder sludge that contains copper wire and other metallics in a matrix of plastic and natural fibres, iron oxides, metallic iron, and other compounds. Characterisation methods discussed include chemical analysis (XRF, ICP-AES, and selected specialised techniques), phase analysis (XRD, SEM, TEM, and optical microscopy), morphology (IFESEM), sizing analysis (screening, Cyclosizing, Infrasizing, Malvern sizing), and general techniques such as particle shape, surface area, and porosity determinations. The applicability of these techniques to the waste products is considered in relation to their advantages and disadvantages, and sampling issues.Treatment techniques considered for the two waste products included comminution, screening, air or water classification, simple water leaching, gravity separation, magnetic separation, flotation, and eddy current separation.Tentative flow sheets were developed for the two wastes. For aluminium dross, it was proposed to use fine crushing followed by water washing to remove soluble chlorides and aluminium nitride, and then desliming followed by flotation of the granular fraction to give a metallic aluminium-rich concentrate. For shredder sludge, it was proposed to use wet screening, water classification, and gravity concentration to produce a copper-rich product and magnetic separation to produce a metallic iron-rich product.

Jan 1, 2004

By J M. Galvin

The traditional engineering approach to assessing stability is based on comparing resisting force (capacity) to driving force (demand), or strength to working stress. In underground coal geomechanics, considerable effort has been expended on quantifying the strength of rock structures. However, this has not been matched by advances in determining the load acting on these structures, reflecting a reluctance by some to embrace numerical modelling to assess load magnitudes and distributions. Numerical modelling is a valuable aid as loading environments are a function of both the stiffness of the mine workings and the stiffness of the superincumbent strata and are statically indeterminate in most cases.This paper defines stiffness, which is often confused with elastic modulus. It shows that, effectively, stiffness encapsulates geology, depth of mining, panel width, pillar width and mining height. Therefore, these factors are variables that need to be taken into account when determining stress magnitudes and distributions about mine workings. A range of examples are presented that illustrate the significance of the stiffness of the superincumbent strata on surface subsidence; the magnitude and distribution of pillar and abutment load; and aspects of bord and pillar mining, pillar extraction and longwall mining. These examples provide bases for identifying the limitations of some empirical approaches to mine design, identifying how to compensate for some of these in design processes; and emphasising the need to make greater use of numerical modelling in understanding and quantifying loading environments in underground coal mining.CITATION:Galvin, J M, 2014. The significance of superincumbent strata stiffness and its impacts on coalmine design, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 3–16 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By S Vearncombe

SpaDiSÖ is a revolutionary approach to the spatial analysis of point data using geometry to analyse geometry! SpaDiSÖ uses each and every spatial relationship and is not dependent on mathematical models. For n points there are n2 û n spatial relationships and, because of the square function, the method yields interpretable results for both small and large data sets. SpaDiSÖ is an alternative to variography for directional studies. At the regional scale, the analysis can assess distribution patterns of mineralisation and potential controlling structures. At the deposit scale, the characteristics of zones of mineralisation such as direction, spacing, high-grade ore direction and grade distribution can all be deduced.

Jan 1, 2000

By T Elms, R Beckman, M Sampson

"In today’s mining industry, the pressure of reducing costs and increasing production while maintaining high safety standards is at the forefront of operational endeavours. A combination of specific mining knowledge and technological advances has helped enable this notion. Fleet management systems have been developed to enable sites to better measure and manage production to improve operational efficiency.The integral part to managing production is having accurate, readily accessible data. This empowers key stakeholders in the management team to drive production reporting, materials tracking and budget forecasting.If a site does not run a fleet management system, manual input is heavily relied upon for production data, which introduces increased risk of human input error. Errors can drive outcomes that don’t achieve increased production at a reduced cost. Alternatively, a fleet management system can have improved accuracy but involves a high monetary investment. Such an investment is not always feasible for smaller mining operations subject to current industry cost pressures.The Emeco Operating System has been developed in alliance with sites such as the Mungari White Foil Operations by satisfying the criteria of a low intensity hardware installation, material tracking data validation processes, remote monitoring, identification of metrics to improve overall operating efficiency and providing the right information to key stakeholders.Citation:Beckman, R, Elms, T and Sampson, M, 2016. Getting Accurate Mine Information to the Right Teams to Drive Production Improvement, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 203–211 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

The Palaeozoic succession of Victoria contains one of the world's major gold provinces with a total production of 2500 tonnes of gold. Larger deposits, including Bendigo (over 800 tonnes Au), are related to Ordovician slates and greywackes, but a wide range of metamorphosed sedimentary and igneous rock types are host to significant gold deposits. Most, if not all, deposits demonstrate structural control, although the controlling structural features are variable between deposits: a majority of deposits comprise quartz veins. It is suggested here that a major factor in making Victoria such a gold-rich province might be a particularly high geothermal gradient in central Victoria during the Tabberabberan orogeny (360-380 my). This generated auriferous metamorphic fluids from underlying successions (?Cambrian) which migrated upwards along active structural pathways. One cause of gold deposition appears to have been fluid reduction by carbon, but other methods are suspected. This model is considerably simpler than the plethora of syngenetic, granite magmatic and lamprophyre-related models that have been proposed recently, but is in basic agreement with Cox et al. (1983). Exploration models for similar gold deposits both within Victoria and elsewhere should take account of the negligible evidence for a major syngenetic contribution to Victorian gold production, and the lack of any clear genetic relationship to particular igneous rock types. A real opportunity exists for new deposit types not identified by the early prospectors.

Jan 1, 1991

By B J. Wilde

Evaluating the resources and reserves in a mineral deposit requires many interdependent subjective decisions. The decision of stationarity is arguably the most important. This decision includes: the choice of domains that subset the entire deposit, modelling the boundaries of each domain, and understanding and considering the nature of the contacts between domains. Reasonable choices are made in consideration of the geological context, the available data, the goals of the study and the available resources for the study. This paper reviews aspects of the decision of stationarity in modern resource assessment with a focus on quantifying uncertainty and using numerical/statistical tools to help the geomodeller. The use of volume/distance functions to quantify uncertainty in domain limits is particularly important and is presented in detail. The use of contact plots provides help with the continuity of grades across domain boundaries. Realisations are not assembled as a branching combinatorial of all possibilities, but as a set of realisations that provide a measure of uncertainty. This paper amounts to a definition of stationarity for modern resource assessment.

Sep 26, 2011

By A R. Hollis, M Heddon

The safe life cycle of a Tailings Storage Facility (TSF) is founded on the fundamentals of proper design, construction, operation and closure. Leinster Nickel Operations (Leinster) utilises four active TSF cells that are cycled between filling (deposition), desiccation, and construction to meet a targeted rate of rise. This results in ongoing and consistent raising of the TSF walls. Critical to maintaining the safe life cycle through this consistent wall raising is precision construction and high frequency quality assurance to ensure compliance to design requirements and TSF walls free from defects. Leinster has recently deployed Intelligent Machine Control technology for TSF construction. Advances in Intelligent Machine Control have decreased variability in construction; ensuring variations are within the tolerances of design. The Intelligent Machine Controls are programed to ensure construction conforms to design tolerances of +/-30mm. This level of accuracy provides assurance of borrow area set out, compacted layers are as per design, compaction monitoring is within the zone placed, scarification between layers to prevent lamination is maintained, and batter angles are set to the correct grade. This level of control provides certainty that construction meets the design intent. In conjunction with Intelligent Machine Control, periodic drone surveys are conducted to verify construction against design. Advancement in survey equipment and techniques allow higher frequency, high accuracy survey to be completed on demand by site based personnel. This provides quality assurance through all stages of the construction phases, as well as the final constructed wall, ensuring compliance to design. Combining Intelligent Machine Control with higher frequency quality assurance provides an increased level of certainty that the TSF construction is defect free and within quality specifications. These recent technological advancements in Construction and Quality Assurance ensure cell raises are constructed to the design intent with greater levels of accuracy and precision than ever before.

Jul 1, 2021

Universities have had a long history in the education of geology graduates, Analysis of this history reveals a record of success, as judged on a world basis. However there have been significant changes in the last 20 years that have impacted on the ability of universities to continue to provide their traditional style of geology education. These changes have increased in the last 10 years. In the teaching side, there has been a change in expectations. Additionally the increasing workload decreases the value of each academic to perform the tasks needed by the new education. In the area of research, the funds provided have continued to decline, in both real and absolute terms, and it is now necessary for universities to seek out funds to pay for their postgraduate research. Additionally, the universities have slipped into the error of what cahn only be termed "academic incest", and research student mobility has decreased to an undesirable level, stifling initiative and new ideas in a number of cases, The only solution is for Government monies to be "directed" - ie that the postgraduate student must leave his or her original university in order to receifve the research stipend/scholarship. On the government front, the government and its agencies have not adequately analysed and recognised the need for the redirection of education and research funds into the needy areas of science and technology, especially those that related to the minerals area.

Jan 1, 1986

By R Minnitt

Two methods of calibrating the parameters K and Alpha for use in Gy’s formula for the fundamental sampling error were investigated. Approximately 480 kg of broken ore from Harmony’s Target gold mine in South Africa was used to compile the replicate samples for two experiments. The duplicate series analysis (DSA) and segregation free analysis (SFA) methods differ in terms of their approach to recovering the sized materials required for the calibration procedure. In this experiment the DSA method split off six more-or-less equal masses of material from a 75 kg lot that was successively crushed to finer and finer fragment sizes. The sublots so formed were split into 32 samples and fire assayed for gold. The SFA method used approximately 250 kg of broken ore crushed to 95 per cent passing 2.50 cm, which was then passed through successively finer screens until a sublot of less than 0.0075 cm was obtained. Each of the 15 sublots obtained in this way were split using a riffle splitter into 32 samples that were fire assayed. A total of 672 fire assays were used in these experiments. The sampling parameters K and Alpha were used for the compilation of a nomogram and to calculate the gold liberation size of the ores. While there are no definitive results in terms of the actual gold grain sizes against which the calculated sizes can be compared, it appears that the DSA method produces more acceptable results.CITATION:Minnitt, R, 2014. A comparison of two methods for calculating the constants K and alpha in a broken ore, in Proceedings Sampling 2014 , pp 165–178 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 29, 2014

In this year marking the centennial of the Geological survey of Western Australia, it is appropriate that we should review the value of the contribution of the Survey, and Australian Geological Surveys in general, to the exploration industry. Most geological surveys in Europe and North America had their origins in the first half of the 19th Century when the burgeoning Industrial Revolution was demanding the identification of new sources of coal and iron ore. Australia, as a young nation, essentially dependent on an agricultural and pastoral industry, and with already discovered vast coal resources in Eastern Australia, had, no great need to explore for new mineral resources. However, with the discovery of gold in 1851, the mineral potential of the country became apparent to the whole world and the first Geological Survey in Australia was set up in 1852 in Victoria under A.R.C. Selwyn. After a number of false starts all Australian States had an established Geological Survey by 1900. It is hard to assess the contemporary value of the early work of the Geological Surveys with respect to exploration, almost all major mineral discoveries were made by prospectors and most mining companies had little time for geologists - although the Chamber of Mines in Western Australia in 1910, did recommend that the Geological survey be granted an additional ten thousand pounds over two years to map all existing goldfields and the country between them, and produce a reconnaissance map of the area east of a line between Wiluna and Edjudina as far as the South Australian border!

Jan 1, 1988

By P Card

“Let’s get discipline and quality into easy to understand evaluations!” Project Managers and MetPlant Operators accept poor quality evaluations because they are generally unaware of what they should expect.The 2010 draft AusIMM ‘Guidelines for Techno-Economic Evaluations’ were collated by a subcommittee of practitioners and are regarded as best practice.They apply directly to projects and metallurgical plant evaluations, including those with a heavy technical basis. They can be applied to technical problem solving where there are no monetary computations. Project Managers and MetPlant Operators should demand that economic models and evaluations follow the six principles. They should become working tools which are easy to understand, fit for purpose, consistent, rigorous, record sources of input data, have key graphs and are rapid to audit.

Aug 8, 2011

Diamond bearing deposits are extremely low grade and require large bulk samples to be tested to determine the grade and quality of the stones. The semi portable plants, for treatment of these bulk samples, have followed the development of commercial processes for diamond concentration. These processes included jigs and diamond pans, which have been largely supplanted by heavy media processes for primary concentration, due to the higher efficiencies in all size ranges. A number'of flowsheets including these processes are presented. The final recovery of diamonds from the bulk sample concentrates can be accomplished by rejigging, adherance to grease or by X-ray sorting. Flowsheets incorporating all the processes are presented. Two plants are described; one incorporating jigging, rejigging and hand sorting; the other using heavy media separation, and wet X-ray sorting.

Jan 1, 1984

By A L. Bennett

It is well understood that designers and constructors must protect the existing surroundings of tunnel construction, particularly in the selection of excavation methods, ground support and waterproofing systems. However, while this can readily address the existing conditions, the tunnel owner and the designers need to consider the changes that are likely to occur during the life of the tunnel. It is typical for transport infrastructure to have a design life of at least a century. While the effects of constructing the tunnel on its surroundings are a short-term effect, the converse case, the protection of the tunnel, and the need to maintain its integrity, will affect developments over and adjacent to the tunnels beyond the foreseeable future. Decisions made during the design phase have the potential either to facilitate development or to hinder it for the long term.Examples principally from Australia, New Zealand, Singapore and Hong Kong show that the provision for future development is addressed in different ways. These have ranged from making no specific provision, putting the onus onto developers to ensure that the tunnels are not affected adversely, to including a loading allowance for future development in the performance specification or contract documents for a tunnel project.These two contrasting approaches have strong points and risks. A highly prescriptive definition of permissible loadings around the tunnel can provide unambiguous guidance for the approving authority and the developer, but runs the risk of being overly conservative to allow for all the envisaged works, while still missing a detrimental combination of effects that theoretically complies with the specified requirements. In contrast, a general requirement to not cause detriment is open to interpretation and potentially difficult negotiations to reach agreement between the tunnel owner/operator and developer and finally the appointed contractor (probably with no contractual relationship with the tunnel owner).In practice, a combination of prescriptive and performance requirements is likely to provide the optimum combination of clarity and flexibility. The author provides examples and recommendations on how such provisions could be structured.CITATION:Bennett, A L, 2014. Protection of ?tunnels in their future environment, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 495–500 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014