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Failure of rock materials is a process of crack propagation. Crack initiation takes place when the crack tip stress intensity K reaches a critical value called fracture toughness, K1C. The rock fracture toughness is known to be affected by the surrounding environment such as temperature, confining pressure and humidity. In order to examine the effect of humidity, a series of semi-circular bend tests were performed under various water vapour pressures in a rock material that is known to be anisotropic. Water vapour promotes stress corrosion of rock and therefore the fracture toughness was found to have a decreasing trend with increasing water vapour pressure. The rate of decreasing the fracture toughness depends on the microcrack density that promotes the migration of water vapour into the rock. Also in an anisotropic rock, the fracture toughness depends on the direction of crack in relation to the anisotropy of the rock material.

Dec 6, 2010

By G Baird, M Seto

Reliable evaluation of in situ stress is an important phase in the analysis and design of underground excavations, particularly for evaluating the stability of underground structures to prevent failure or collapse. A technique for the estimation of the full stress tensor based on acoustic emission (the Kaiser effect) is being developed and trialed at the WA School of Mines. The result obtained compare well with the standard over-coring method. The advantages of the technique are that it is relatively cheap, non-time consuming and is applicable to in situ stress measurements at depth in remote regions.

Jan 1, 2002

A mineral grain finder is described which is easily constructed to fit onto the stage of a standard reflected light ore microscope.The device is most useful in relocating particular grains or mineral associations on 30 mm diameter polished sections. The use of the grain finder in the teaching of ore microscopy is outlined.

Jan 1, 1988

By A C. Robertson

World urban expansion puts constraints on the available land surface area of our major cities both for accommodating people as well as providing infrastructure and services whilst at the same time attempting to preserve the remaining natural environment. Whilst consideration is often given to underground planning for private and public transport infrastructure, the author is of the opinion that the current lack of underground planning of our cities that are suitable for underground development will have major long implications when finally the need for underground space planning is critical and ultimately recognised. This paper identifies the need for our city planners to integrate surface planning and underground planning as a ‘total planning solution’ where the city plan incorporates the elements of underground space planning as identified in this paper. Investigations by the author reveal that there are very few cities in the world that actually incorporate underground space planning in their city plans. The author uses the City of Brisbane as a case study for the potential introduction of underground space planning as part of the city plan. Despite efforts by the author to include the planning concept of underground commercial development in the latest Brisbane City Plan 2014 as well as four underground space workshops in Brisbane over the past 20 year through the Australasian Tunnelling Society (ATS), underground space planning for the City of Brisbane, apart from infrastructure projects, is not considered of significance to the City of Brisbane.CITATION:Robertson, A C, 2014. Commercial underground space – planned development for the future, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 513–518 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

State ownership of mineral in the ground is not newthe Regalian Right is an ancient concept. And the compulsory purchase of land and the minerals beneath it by the State or a body approved by the State (Fitzgerald, 1952) was a principle well established and enforced in practice over a hundred years ago, when such powers became a practical necessity during the period of railway building in Britain and elsewhere:The acquisition of mineral properties which stand in the way of public construction projects still goes on. But in recent years nationalization is being increasingly undertaken as part of the planned use of national resources, for the closer regulation of economic activities, or merely, so it would seem, as a matter of political expediency or national pride. For instance, the unsevered coal in Britain came under State ownership in 1938 in an attempt to simplify a complex pattern of freehold titles which were impedingplanned mining operations. Later, unsevered minerals became a factor in negotiations arising under various town and country planning acts. The acquisition of the Rio Tinto mines by the Spanish Government implies political aspirations. Or State purchase may even be accidental: it was the easiest course for the Sierra Leone Government consequential upon its failure to prevent widespread trespass over legally-held diamond privileges in 1955.This paper has been prompted by problems that have arisen when properties containing unsevered mineral have been expropriated by the Crown in New Zealand: expropriations, it is true, that have been on a small scale in rela...

Jan 1, 1957

The ready solubility of gold in dilute aqueous solutions of the cyanides of the alkalies or alkaline earths provides a convenient method for the separation of the precious metal -from the large surplus of associated materia1. The finely ground ore is pulped with a weak solution of cyanide, agitated to dissolve the gold, filtered and washed. The lowgrade filtrate is then clarified and the gold precipitated by some electronegative agent, the most usual being finely divided zinc or zinc dust. The slight precipitate is collectedon some form of filter coated with a filter aid, the filter cake being then known as "gold slime".A typical analysis of this slime is given in Table 1.

Jan 1, 1956

By Chand F

The silver deposits of Rockvale near Armidale, N.S.W., occur in fissure veins in epi-Permian granite. The ore is fine grained, mineralogically complex, and contains twenty-seven different minerals including eleven silver minerals. The ore is characterized by a unique multiple unmixing from a sphalerite solvent. The following minerals have exsolved from solid solution in sphalerite: pyrrhotite, chalcopyrite, cubanite I, cubanite II (chalcopyrrhotite), valleriite, "brown" stannite, "olive" stannite, argentian tetrahedrite, pyrargyrite, and an unknown grey-white mineral. Several of these minerals derive from a second-stage unmixing, the immediate solvents of which are the products of earlier exsolutions.INTRODUCTIONSmall silver-rich base metal deposits occur at several localities near Armidale in the New England district of New South Wales. Chief among these are the Tulloch Mine and the Rockvale Mine at Rockvale, 27 miles SE. of Armidale, and the Tait's Gulley deposits some 15 miles NE. of Armidale.At Rockvale (Kenny, 1928), irregular lenses of lode material, principally quartz and calcite, occur along a zone of shearing in biotite granite and altered sediments. The orebodies had a maximum width of 6 ft but averaged 2 ft 6 in. The largest lens was 150 ft long and 50 ft high. The Rockvale deposits were worked for both arsenic and silver; 2,897 tons of arsenic were produced but no figures are available forsilver.Little is known of the Tait's Gulley deposits which occur in folded arenites containing small but rich veins of pyrargyrite with base metal sulphides.The sediments in these localities are possibly Silurian.

Jan 1, 1962

WHEN the writer resided at Zeehan, qn the West Coast of Tasmania, some years ago, he took a keen interest in the geology of the district and availed himself of the opportunity to investigate occurrences, of the varied minerals in which the field abounds. The following notes were compiled as a result of one of his periodical visits to the outlying mining districts, when an examination was made of the bindsay Reward tin mining property, which has an area of 140 acres. This is most easily reached from Renison Bell, the centre of the North Dundas tin-fields, on the Emu Bay railway, 'about' eight miles north east of Zeehan. Thence a pack track some 14 -miles long connects with the mine, crossing the Piemah River by a fine suspension bridge.The mine itself is situated on the main south leading spot of the Parson's Hood Range, at an altitude of some 1600 ft. above sea level. The Parson's Hood Range is composed of granite and is an extension of the rugged Meredith Range. A remarkable feature is the uniform topography of the surrounding country when viewed from the peaks. Except where dissected by the rivers and creeks, the surface is practically level and, indeed, affords a striking illustration of an ancient uplifted peneplain.The mine has been opened by means of trenches and adits, and the ore-body proved to extend for a length of 30 chains, with an average width of about 100 ft. Its general trend is west-north-west, and its dip, which is steep, corresponds to that of the country-rocks. These latter, which are of sedimentary origin and generally regarded as of pre-Silurian age, have been tilted at high angles, consequent, no doubt, on the crustal movements produced by the intrusion of the huge granitic masses which now form the high ranges in the vicinity.It may be here remarked that it is not Within the scope of this paper to deal with the sequence of events leading to the geological structure...

Jan 1, 1923

This evening I would like to speak about men for the mineral industry.It is trite to say that the mining industry is expanding rapidly and that technically trained men are in short supply. How short is difficult to assess and impossible to quantify.The industry has been traditionally managed by technically trained men experienced in the ways of their fellow men. Let us start with the assumption that men with this training and experience are essential to management of mining and metallurgical enterprises.I suggest that we do this as it avoids argument with those who are beginning to suggest that such men are not so important as they used to be; who are suggesting that the latest sophisticated business management schools can produce managers who can straight out of school join the upper echelons of an organization and successfully manage it by the use of modern systems and techniques without the need to rub shoulders with men of all callings and get their hands dirty in the process.This kind of thinking brings to mind the modern cargo ship which is equipped with all the latest gadgets of science. It can find its way from Sydney to Auckland with no one in the engine room and the man on the bridge spending most of his time writing to his wife or reading the latest novel.How often do we read of this ship being tied up in Sydney because the crew sympathizes with the cook who has been slighted by some uncomplimentary remark about his toheroa soup? Here is a pieceof sophisticated machinery stopped through no technical fault, but held up by the whim of man. The understanding of man by man can spell the success or failure of any endeavour. A single man can leadan organization to the pinnacles of success, or doom it to utter failure in spite of modern systems and techniques.So let us start from the point that people matter.Through the years our Institute has been fortunate in having many members who have felt strongly...

Jan 1, 1970

The profitability of individual ore blocks can be classed as clearly profitable, clearly not profitable, and those in between which are by nature quite sensitive to their major cost and revenue drivers. It is often the case that the most effort goes into the least profitable ore blocks to ensure that these will in fact not generate a loss. In these cases a cut-off grade policy is often not sufficiently live to separate individual sources given the volatility of financial markets and individual circumstances of some sources particularly in remnant operations such as Mount Isa MinesÆ Lead Mine. Standard sensitivity analysis can determine which factors stope profitability is most sensitive to. However, this does not usually indicate the likelihood of any input change, nor the combined effect of multiple inputs changing. The author attempted to modify the Lead Stream financial model that determines cash margin by inserting probability distribution functions and then using Monte Carlo simulations to determine the probability of any particular ore block making a profit. This effectively demonstrates the combined effect of varying a number of inputs simultaneously to provide a probability of making a profit. The limitations of this analysis lie in the accuracy that individual probability distributions can be specified. Attempts to generate valid functions from first principles have proved difficult for a number of reasons and these are discussed along with some practical alternatives.

Jan 1, 2002

By Eggleton R. A

X-ray diffraction techniques are commonly used in the identification and quantification of fine-grained materials. A relationship exists between the size of crystals in a sample and the degree to which they diffract X-rays. The Scherrer equation relates the broadness of diffraction peaks to the size of crystals responsible for diffraction (Klug and Alexander, 1974). Relatively large crystals of the order of I - 10 ¦m strongly diffract X-rays; the diffractogram of such crystals exhibit narrow intense peaks. As the size of the crystals in a sample is reduced, diffraction peaks become broader and less intense. Crystals less than 10 nm generally exhibit broad, diffuse and low intensity peaks. Some material is so fine-grained and poorly-diffracting that X-ray patterns show very little information in a normal one-hour scan thereby necessitating very long acquisition times of up to 12 hours. The term poorly-diffracting material (PDM) was coined for such material found within the bauxite deposit of Weipa, northern Queensland (Tilley and Eggleton, 1994; 1996). Common regolith minerals such as hematite, goethite and layer silicate clays are quite commonly fine enough to possess a poorly-diffracting character. Noncrystalline and poorly crystalline Fe-Si-Al-oxyhydroxides such as allophane, opal, ferrihydrite and hisingerite, have either a nondiffracting (amorphous) or poorly-diffracting nature (Eggleton, 1987).

Jan 1, 1997

By Pilon CG, Deakin RC

It is proposed that a waste rock dump be constructed on slopes consisting of soft colluvium and weathered Chim Formation mudstone at the Porgera Gold Mine, in Enga Province, Papua New Guinea (PNG). Geolog- ical, geomorphological and geophysical investigations were conducted in support of geotechnical studies to assess the physical character of the 6km2 site. Geomorphological studies focused on the extent and nature of colluvium cover and landslide activity. Detailed ground traverse mapping resulted in classification and delineation of eight terrains and seven material types. Seismic refraction and resistivity profiling, combined with drilling, provided subsurface data. Results were presented as standard profiles, coloured contoured sections and plans. Subsurface features, including deep colluvial channels, buried cliffs, slump blocks and buried alluvial channels, were identified. Results of the combined investigations allowed designers to model the colluvium/ bedrock surface and identify critical areas of deep, mobile colluvium and weak bedrock. A design approach was developed which accounted for the morphology of landslide systems and distribution of colluvium types.

Jan 1, 1991

In-pit crushing and conveying (IPCC) is being increasingly considered as an alternative to traditional truck-shovel mining methods. The move towards IPCC is driven by a number of factors including the potential to reduce greenhouse gas emissions, the availability of skilled labour and the need to increase extraction rates to levels that present significant challenges to traditional methods.When considering the relative performance of IPCC and truck-shovel methods, the outcome can be inadvertently impacted by either the use of different simulation approaches, or techniques that do not adequately model the processes in sufficient detail.A simulation approach is proposed that models both IPCC and truck-shovel using the same software platform and is capable of functioning at a wide range of resolutions from life-of-mine scale through to second-by-second asset tracking level. The simulation framework also holds models of processing equipment and hence the mining simulations can be extended to gauge the impact on downstream plant.The approach, known as mine-process operational simulation (MPOS), can be tailored to the level of information available and hence the type of study required, ie order of magnitude, prefeasibility, feasibility, or detailed design.Using information from block models and a range of detailed equipment and process models, MPOS can span major system discontinuities, typified by the mine-plant interface, to allow the estimation of final mine and plant product specifications.

Dec 6, 2010

By OÆBrien R. T

A small static bed was used to study the thermal cycles required for the heat hardening of pellets based on synthetic magnetite concentrates and a naturally fine hematite. This apparatus can be employed to yield broad process data for the design of a recuperative strand system operating on the magnetite concentrates.Various alternatives are given for a process to heat harden the hematite ore but a preference is given to the production of a self fluxing pellet. Bond types and general mineralogical structures are interpreted against the optimum firing cycle necessary to produce a defined quality of pellet.INTRODUCTIONThe work reported in this paper extends that on the "Heat Hardening of Artificial Magnetite Pellets", which was described at the International Symposium on Agglomeration, sponsored by the American Institute of Mining, Metallurgical and Petroleum Engineers at Philadelphia, U.S.A. in April 1961. Whereas that work was of a more basic nature, serving to illustrate the suitability of artificial magnetites with various admixtures, to the application of heat hardened pellets, on this occasion the aim is to illustrate the procedures which were used to establish the dimensions of commercial recuperative strands for Australian raw materials.The nature of the pellet feed, Le. relatively uniform spheres of + i in.-Yi6 in. diameter, makes it possible to use small scale static pots for test work. By the use of a closed system and the measurement of suctions, gas flows...

Jan 1, 1963

By J B. Gemmell, D R. Cooke

Recent mapping at the Kelian epithermal gold deposit in East Kalimantan, Indonesia has delineated intrusive and extrusive-phreatomagmatic breccias, their magmatic roots, and late-stage endogenous domes of a maar-diatreme complex. The Kelian epithermal system is characterised by a wide variety of mineralised and unmineralised breccias, which include tectonic, hydrothermal, phreatic and phreatomagmatic varieties. Phreatomagmatic breccias and associated igneous rocks post-date early stage alteration and mineralisation, and pre-date main stage precious and base-metal mineralisation. This study emphasises the spatial, temporal and genetic links that have been drawn between diatremes and both epithermal and porphyry systems in volcano-plutonic arcs.

Jan 1, 1999

By Bujtor G. J, McMahon D. W

This guide to the understanding of ore reserve estimation is the revised version of a report with a similar title circulated within the CRA Limited (CRA) group of companies in mid-1980. It is the principal result to date of an Ore Reserve Study commissioned by CRA in late 1977.This guide to the understanding of ore reserve estimationis the revised version of a report with a similar titlecirculated within the CRA Limited (CRA) group ofcompanies in mid-1980. It is the principal result to dateof an Ore Reserve Study commissioned by CRA in late1977.The study was prompted by two ore reserve situations.The Zinc Corporation and New Broken Hill Consolidated,Broken Hill, had reached the point of havingto find a replacement 'for their traditional ore reserveprocedure and Mary Kathleen had to admit publicly thatore reserve predictions would not be realized. Thesewere not however the only problems to be looked at. Asmentioned more fully later, other ore reserve situationswere known, or were met during the study, in copper,gold and nickel as well, where poor realization: expectationratios had ranged from embarrassing to disastrous.These made it clear that ore reserve estimation had to belooked at afresh.The fresh look has resulted in a broadening of theconcept of ore reserve estimation from its traditionalpurely computational basis to an approach embracingall the many things that can affect expectation andrealization as essential factors. Hence this guiderepresents a gathering together of what has been learnedand what should be known to all those concerned withore reserves in any of its diverse aspects.The study has been marked"by a number of changesof thinking. At first the aspects that appeared to requireattention were two; recognition that an ore reserve statementwas an estimate, not a precise calculation; and asearch for im improved estimation procedure adapted tolow grade ores with narrow economic margins. Threeyears later the view was that the need was to incorporateinto ore reserve estimation all relevant aspects of theproposed mining operation from choice of a samplingmethod to sales contract specifications.This study is thought to be unique in being frankabout weaknesses in ore reserve estimation and intreating failures not as natural disasters (like drought orflood, which have to be endured) but as potentiallyavoidable. It has led to three principal conclusions.

Jan 1, 1982

By M Ahler

Future developments in the mining sector will be driven by the need to increase safety, ecological sustainability and efficiency. Autonomous systems represent a huge step towards achieving these goals. This paper describes the basic infrastructure of an autonomous system – essentially a network of distributed sensors. Although the sensors are distributed, the overarching communication network with its related middleware offers a transparent and uniform layer. This middleware acts as an abstraction layer which priorities information and provides information to other platforms on request. This permits higher-level autonomous functionality to utilise all information available in the system regardless of where data has been generated or via which physical communication link it has been processed.The Personnel Proximity Detection (PDD) system is described in detail as an example, with details not only of the system itself, but also of the essential full integration and how the abstraction layer allows this technology to be plugged in at any location of the network. The paper ends with a summary of the content and a conclusion.

Nov 22, 2011

By A Jäger, J L. Lett, J Rachocki and B Mobilio

The Newcrest Mining Limited Cadia East Panel Cave mines near Orange, New South Wales, Australia commenced production 1200 m below the surface in May 2014. Understanding the mine-wide impact caving had on excavation stability was a primary objective to ensure a safe working environment as production ramped up in the Panel Cave 1 operation and establishment activities were implemented in Panel Cave 2. The impact of cave interaction between Panel Cave 1 and Panel Cave 2 and establishing monitoring systems to assist mine planning and production as both caves joined is explained in this paper. Monitoring tools such as a microseismic system, open holes, HI-cells, extensometers, fibre optic sensing, cave markers, closure monitoring, underground observations and damage mapping were used to characterise the performance and position of the cave back. The data and observations collected were compared to predictions from numerical and empirical methods and used to calibrate the numerical models for forward prediction and to develop site empirical design tools. The results and methodology for monitoring deep high-output caves are the key discussion points in this paper.CITATION:Lett, J L, Jäger, A, Thornhill, T, Rachocki, J and Mobilio, B, 2016. Geotechnical challenges in cave monitoring – a modern approach, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 203–216 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By Knevitt L. T

PART 1Details of Kiewa Scheme.Introduction.Topography.Preliminary Investigations.Geology.Description of Project.Details of Main Works.Main Transmission of Power.Construction Facilities.PART 2Underground Works.Summary of Projected Works.Administration.Labour.Surveying.Safety and Accident Prevention.Medical Attention and First Aid.PART 3No. 4 Head Race Tunnel.Summary.Geology.

Jan 1, 1950

By M I. Roberts

Corporate and workplace culture, as many owners, directors, executives and managers know, is by far the most powerful determinant of productivity. It’s much more significant than buildings and equipment. Yet although no one today would build a building or machine without a plan, few leaders have a plan for building and sustaining a safer and more productive culture.Using practical ways, culture can be planned and shaped as desired. Success requires implementing a project plan for changing the systems that drive behaviours that in turn shape attitudes. The combination of behaviour and attitude together with leadership largely shape culture.To improve performance, leaders need to:1. improve the organisational systems that drive behaviour2. action a project plan for improving specific performance metrics 3. demonstrate leadership that is conscious, disciplined, committed and passionate for purposeful use of human energy.This paper explains all three factors in practical ways with operational and corporate examples. It details understanding and applying the power of fundamental statistical analysis tools to recalibrate, focus and drive proactive leadership that takes responsibility for process improvement, supporting people and ensuring accountability.Experience and practical understanding of human and organisational behaviour confirm that the Measurement ? Analysis ? Reporting system combined with conscious leadership is by far the most powerful driver of behaviour. This wisdom produces profound changes in leadership style and behaviour. It develops outstanding leadership to create and sustain a safe and highly productive culture reliably producing consistently high quality products. It is the key to developing accountability, employee retention and a sustained competitive advantage.CITATION:Roberts, M I, 2016. Building safe, productive cultures and leadership, in Proceedings International Mine Management Conference, pp 163-178 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 22, 2016