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Models of the genesis of existing ore oodles and targetting of exploration for new mines are greatly enhanced by an-understanding of the plate tectonic environment existing at the time of mineral emplacement. In areas of recent or active tectonism, a study of the present-day crustal and upper mantle structure is an obvious starting point in unravelling the evolution of the accessible upper crust. Bougainville is the northern-most island in the Solomon Islands arc. A 7km deep trench almost 100km off its western coast marks the commencement of subduction of the Solomon Sea plate beneath the Pacific plate. As outlined by the seismicity, the subducted crustal slab under the southern half of Bougainville reaches the axis of the island at about 100km depth, from which point it dips near vertically another 300km into the upper mantle. Large surface blasts at the Bougainville Copper Mine at Panguna, Bougainville, Papua New Guinea were used to derive an unreversed upper crustal profile of the island. The crust appears to be relatively simple, being comprised of a 5km deep layer with a P-wave velocity of 4.5km/sec, overlying a l0km thick layer with a P-wave velocity of 7.2km/sec. Constraints on the 15km mantle depth were provided by the identification of both P to and S to P phase conversions of seismic waves from local shallow earthquakes at the Moho boundary. An upper mantle velocity of 7.95(¦ 0.15) km/sec was measured from travel times of selected shallow earthquakes along the strike of the island arc.

Jan 1, 1987

Professional engineers of today require a wide array of experience and knowledge. It is true that commonly engineering degrees do teach the technical requirements well, but do fall short in the way of teaching other non-technical issues of professionalism to the student. Today calls for an engineer who does not only have a high standard of the technical knowledge required for their degree, but also has a broad range of experience in areas that are becoming increasingly important in engineering. The importance of social responsibility, liability and interpersonal relations is high. Through the face of the changing world, it has become clear that there is a need for a new type of engineer, who has a broad range of expertise, as well as the typical technical abilities required. This paper will outline these non-technical issues and propose ways of combining these ideas into the mainstream engineering degree.

Jan 1, 2004

By R Badreddine, J Rose, L De Windt, P Chaurand, L Raimbault

Municipal solid waste of incineration (MSWI) bottom ashes are recycled as aggregates in civil engineering. These heterogeneous materials are composed of crystalline and glassy solid phases which contain trace metals, presenting a potential risk to the environment. Secondary ion mass spectrometry (SIMS) can provide quantitative chemical information, in particular the localisation of metals at trace level. Unstable glassy phases formed during incineration are present in relatively high proportions. Their analyses suggest a continuum between melilite-bearing glasses and dark glasses enriched in iron with abundant spinel aggregates. These primary glasses are enriched in zinc (~4500 ppm) but depleted in lead (~800 ppm) by comparison with the bulk chemical composition and reference materials. Heterogeneous cementing and encrusting admixtures on coarse grains are studied in a second step. SIMS imaging suggests a superposition of band zones including an intermediate layer enriched in iron oxyhydroxides and a superficial layer with calcium accumulation. A strong spatial association between lead and iron is systematically observed. Extended X-ray absorption fine structure (EXAFS) supports these observations by demonstrating that lead co-precipitation within iron oxyhydroxides, or sorption on their surfaces, may be a main containment process in the cementing and encrusting admixtures, whereas lead speciation is globally more complex in MSWI bottom ash.

Jan 1, 2008

The considerations which led to the decision to_ install discs at the Dampier Pellet Plant of Hamer ley Iron Pty. Ltd. are described. Initial testwork showed that the ore could be ground dry in open circuit to a Blaine index of 2500 cm2/g and that it pelletized readily. The various design criteria including diameter, slope, speed, motor size, depth of sidewall, feed point and water spray location were then determined. Plant performance after commissioning is described including the various problems encountered and the modifications since carried out to overcome them. The main problem was quickly identified as disc feed rate control. Various bin and bin feeder modifications were tried to overcome the effects of the fluidising characteristics of the dry ground ore. Other factors found to affect disc operation are ore size distribution, additives and operator competence.

Jan 1, 1974

This paper looks at the development in management education for engineers at the undergraduate level with particular reference to mining engineers. The management core content of the engineering degree course at Ballarat C.A.E. is described is some Detail.

Jan 1, 1986

This paper looks at the development in management education for engineers at the undergraduate level with particular reference to mining engineers. The management core content of the engineering degree course at Ballarat C.A.E. is described is some Detail.

Jan 1, 1986

Airblast overpressure legislative limits can be extremely difficult to meet throughout Australia, which has by far the most stringent limits of any nation in the world. As the difficulty in meeting the limits is strongly dependent on the scale of mining, it is not surprising that the Australian coal mining industry is experiencing particular difficulties in meeting these limits. Eight full scale overburden blasts have been modelled with respect to overpressure impact for a strip coal mine, involving both dragline (cast) blasting and pre-strip (non-cast) blasting. Overpressure levels in the range 100 to 125 dBL have been measured at distances varying from 2.4 to 5.7 km, and modelling has successfully estimated both the amplitude and shape of overpressure waveforms to within an average of 1.2 dBL. Typical errors of prediction are around 0.6 dBL. This accuracy of prediction has been achieved by considering the impact of only the face holes, and the accuracy of prediction of both shape and amplitude suggests that it is these holes which dominate the environmental overpressure impact at distances in the range two to six kilometres, for cast and pre-strip blasting operations. Modelling has been based upon the Elemental Overpressure Wavelet proposed by Richards and Moore (2002), incorporating actual hole coordinates, actual delay timing, and assumed delay scatter statistics. The incorporation of delay scatter statistics has been particularly significant, and allows the determination of the range over which the peak overpressure levels are expected to vary. To date, modelling has considered only the use of conventional pyrotechnic delays, though simple adjustment to the scatter definition would allow estimation of overpressure levels, and their variability, with electronic delays.

Jan 1, 2004

By G Brooks

The control of phosphorus in steelmaking is one of the famous challenges of pyrometallurgy. It is well established that highly basic slags, the presence of FeO in the slag and lower temperatures (less than 1650°C) are favourable for phosphorous removal. The thermodynamics of this reaction have been extensively studied under laboratory conditions and the general trends confirmed through industrial trials. However, in general, phosphorus slag/metal distributions measured in industry are far from equilibrium and quite specific to the oxygen steelmaking technology being used. This variability was quantified by Urban, Weinberg and Cappel (2015), who found that the phosphorus partition ratio measured in plants varied with blowing practice, stirring intensity and even converter life. Some recent kinetic studies by Gu, Dogan and Coley (2017) have shown how the kinetics of these reactions vary with FeO content and dissolved sulfur at the droplet scale. A global kinetic model by Rout et al (2018) provides meaningful predictions of where dephosphorisation occurs in an industrial basic oxygen furnace (BOF) and some recent heat transfer modelling by Madhavan et al (2021, 2022) implies that temperature difference between droplets and slag has a role to play in explaining why equilibrium is not achieved. This paper will review the current state of knowledge and provide suggestions on predicting phosphorous removal for industrial operations and how greater removal could be achieved.

Jun 19, 2024

DIVERSITY There are plenty of examples to show that diversity has been the fundamental downfall of many organisations, particularly when you consider the international position. What about core business, the return of companies to key competence directions and market focus. The stockmarket for instance defines groups and companies in key groups of core business. The expectation is that companies toe the line and do not diversify across their areas of defined expertise. In essence, the market has given notice that the requirements are to focus and stick to our core business. So what right does the conference have to suggest that diversity is the key to prosperity. Hasn't the organiser read the book, studied the history, listened to the market - obviously not. Have they got it wrong, My feeling and belief is no - the organisers have got it right. However, the matter is not as simple as first perceived. What is Diversity, or Diversification as I would prefer? Is it a product position? Is it a geographic position? Is it an expansion or change in services offered? Does a gold mining company diversify into copper or diamonds or aluminium or nickel? Does a gold miner in Australia diversify into China or Kazakhstan or West Africa? How do the two relate? They don't. A successful company will always possess a 'core competence' not so much a 'core business'. The best example of this is the service company extraordinaire - McDonalds. They don't sell hamburgers or french fries, they sell a service, a convenience, a lifestyle. The core business is hamburgers and if McDonalds were to diversify further into new styles of hamburgers, I suggest to you they would fail. But if McDonalds were to diversify into other products based on their 'core competence', provision of service, then I would suggest to you they would be very successful. The service procedure, service machine, service system, the formula, stava the rnnetant the nrnrlnrte -

Jan 1, 1996

At some time in the mining life of an open cut coal deposit, consideration is usually given to determine the point at which underground mining becomes an economic proposition or even necessary. This can occur anywhere from the pre-feasibility project stage to decades after commencement of mining. Options which can be considered include the extension of the life of the open cut by use of larger equipment, the utilisation of highwall mining techniques and the introduction of low capital start-up or full underground development. The primary focus is always the minimisation of the total unit cost (including capital )of clean product. The transition point at which an undergound mining operation becomes more economic than an open cut operation is not a simple evaluation and depends on many factors, particularly on the nature of the deposit itself. The main general determining factors of the transition point are related to the three factors of mining resource, the mining method that can be used and mining cost issues. Mining resource issues include geography, geotechnics, strip ratio, geology and the size of the deposit. Mining method issues include highwall mining, extending the life of an open cut, the environment, available roof support technology, product yields and the availability of appropriate workforces. The mining cost factors discussed include capital and operating costs and the impact of productivity and management. All these factors impact to a varying extent on the transition point.

Jan 1, 1997

ADDRESS BY THE PRESIDENT OF THE INSTITUTE (MR. J. G. SYMONS) IN PRESENTING THE CERTIFICATE TO ROBERT COLVILLE BRADSHAW, O.B.E.Today it is my privilege and pleasure to introduce to you, Robert Colville Bradshaw. O.B.E., the third New Zealander to be honoured with Honorary Membership of The Institute. Sir William Hudson and Mr. C. H. Benney were the others.Mr. Bradshaw has been an Affiliate Member of The Institute since the formation of the New Zealand Branch in 1966. Like his friend Matt Benney. Bob Bradshaw is an accountant by training. Last June he retired as senior partner of the firm of chartered accountants, now known as Wilkinson Wilberfoss, with which he served from January 1929.Mr. Bradshaw grew up in New Zealand attending the Terrace School in Wellington, the New Plymouth Boys' High School where he was a boarder, and completing a Bachelor of Commerce at the university now known as the Victoria University of Wellington. He is an elected Fellow of the New Zealand Society of Accountants and an Associate of the United Kingdom Institute of Cost and Works Accountants.

Jan 1, 1977

By Z Fu, E Topal, O Erten

"Mine waste rock management involving waste rock movement and placement, is a critical aspect in the planning of open pit mining operations, as the waste rock haulage cost can be the largest portion of the mine operating cost. The concept of sustainable development in the mining industry also encourages environmentally friendly waste dumps that have zero hazards to people and the surrounding environment. Therefore, a detailed waste management schedule must satisfy economic and environmental considerations. However, the available tools in the market cannot provide optimal waste dumping schedules to meet all these constraints. This paper introduces a user-friendly and automatic tool to optimise the waste dumping schedule, which minimises the haulage cost, and covers the encapsulation of reactive materials to minimise acid mine drainage problems. This tool has been developed by using a new mixed integer programming (MIP) mathematical model that considers both single-lift and multilift dumping scenarios. The application of the proposed tool on a data set collected from a gold mine shows that the multilift dumping scenario has provided a more flexible and economical waste dumping schedule than the single-lift scenario, and both scenarios satisfy environmental requirements.Citation:Fu, Z, Topal, E and Erten, O, 2016. A Modified Software Tool for Mine Waste Rock Dump Planning, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 229–242 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

By M M. M LT Tassinari, A B. Braz, L M. SantÆAgostino, C Ulsen

Several mineral resources have been recognised to alkaline igneous rocks. In general, these mineralisations present low P grades, so a complex concentration process is required to achieve commercial grade concentrates. This process is guided not only by the ore characteristics, such as apatite grain size and liberation degree, gangue minerals and slimes content, but also by different apatite varieties, iron oxi-hydroxide surface coating and roughness. The main techniques applied to apatite and phosphate ore characterisation, such as optical microscopy, cathodoluminescence (CL) microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), surface techniques and magnetic separation are discussed, aiming to evaluate distinct apatite varieties and their technological behaviour.

Jan 1, 2008

Although the effects of sea level changes on ore concentration processes are to some extent obvious with certain deposits, e.g. beach placer deposits, they have been largely overlooked with others such as Mississippi Valley type lead-zinc deposits. It is contended that sea level variations may have more profound effects on a wide range of deposits than has previously been appreciated. These deposits include not only placer'and residual deposits but also stratiform copper deposits, Mississippi Valley type deposits, stratiform manganese deposits and Minette type iron deposits. Sea levels in paralic basins profoundly affect the influx of 'detrital sediment, and this has to be suppressed to allow for the accumulation of thick rich deposits of coal evaporites, phosphate or metalliferous sediment. Emergence can be associated with oxidized waters, erosion, and,solution of soluble rocks. Submergence can reverse the Eh trend and can lead to preservation of ores. Both realms of surficial sedimentary environments and subsurface diagenetic environments can be affected by changes in water pressure, gas pressure (pC02), Eh, pH, and temperature as sea levels fluctuate. Even relatively small sea level changes may have profound effects. For example, there is some evidence to suggest that when the level dropped below 100 metres about 10,000 years ago, the Red Sea became isolated by the sill at Bab el Mandeb in the south, and evaporated away to leave a series of shallow lakes. The Red Sea is 1 to 2 km deep. It was at times such as this that the well-known copper-zinc mineralization developed in the Red Sea trough. Changes in sea level also affect the stability field of gas hydrates which can yield large volumes of gas leading to mass movements on the sea floor (Warnke, 1986).

Jan 1, 1987

By C Buchanan

For a long time there has been a known relationship between the northern Heavy Mineral (HM) deposits of the Murray Basin to the extensive north east trending ridges in the area. These ridges have been a targeting tool for exploration and have uncovered some significant discoveries, some of which have turned into mining projects. Bemax’s Ginkgo and Snapper deposits are good examples of how the faulting helped create an economic deposit but also result in significant planning issues in the exploitation of these deposits. Material balance, induration and pyrite issues have been made easier to manage through good geological understanding of the deposits.

Aug 22, 2011

The earth is a planet limited in size and limited in total resources. For the forseeable future, it is the only available habitat for mankind. Therefore, it follows that the more we know about our planet the better we can utilize its space and its resources for our well-being now and in the future. But, to accomplish this, we need reliable basic information. Geosciences provide such information. Recently, Dr. M. King Hubbert took note of the important effect of the geosciences on society, on how we think, and how we live. In the first century of modern geology, 1780- 1880, the influence of geology was primarily on how we think, i.e. changing our concept of the earth from one with a short catastrophic history to one that developed gradually over enormous spans of time. In the second century, 1880-1980, the emphasis was on how we live, on expanding the knowledge base so that we could more easily find and utilize the earth's resources. Now, in the third century, i.e. from 1980 towards the year 2000 and beyond, we should concentrate on both how we think and how we live; i.e. how we can better estimate potential global' resources and how we can manage these resources for maximum benefit to mankind. Like other sciences, the geosciences build upon what has already been done. Progress is achieved by using the thoughts, measurements, and observations of past workers, adding to these the insights from new experiments and from new concepts. Geology has its own methodology and approaches; but more than most sciences, it calls also upon the tools of physics, chemistry, mathematics, engineering, and biology to help solve its problems. Today's increasing population, increasing industrialization, and increasing complexity of modern society demand more detailed geoscience information so as to better use the land, reduce geological hazards, provide an inventory of resources, facilitate waste disposal, and prepare for long-term effects such as changes in climate and sea level.

Jan 1, 1986

Coal washing practice can be improved not only by critical examination of the plant being operated but also by studying plants operated in other areas. The developments at the Australian Iron & Steel Pty. Ltd. plants are discussed in relation to experiences there as well as developments which have taken place in Queensland in recent years. Early A.I.S. problems involved small coal cleaning in heavy medium cyclones and flotation. A proposed future plant flowsheet for A.I.S. is considered in the light of these experiences. Reference is made to plants operated by the Thiess, Peabody, Mitsui Coal Company Pty. Ltd. at Moura and the Utah Development Company's plants at Blackwater and Goonyella in the development of coal washing prac- tice in Australia.

Jan 1, 1975

The mineralogy, maero- and micro-textures of Thackaringa ore are simple and have many counterparts among base metal-quartz-siderite vein type deposits elsewhere.The ore consists predominantly of galena, sphalerlte, chalcopyrite, tetrahedrite, and arsenopyrite in a quartz and siderite gangue. Silver minerals, as such, appear to be lacking and silver values are no higher than in other sulphide ores of this type. These features contrast very markedly with those of the A.B.H. Consols Lode which appears to have emanated from the north end of the Broken Hill Main Lode Horizon during high grade regional metamorphism. The Consols Lode has been regarded as of Thackaringa type, and both are regarded as possibly arising from the remobilization of Main Lode Horizon ore. Whilst this may yet prove to be so it appears that the marked differences in mineral composition between the Consols and the Thackaringa types, would require somewhat different modes of regeneration.Thackaringa ore, as well as A.B.H. Consols ore, on this basis, would necessitate the development of a metahydrothermal ore fluid to account for their present apparently hydrothermal (or pseudo-hydrothermal) constitution...

Jan 1, 1967

In 1989 Henry Fairlie wrote a cover story for The New York Republic, 'Fear of Living'. He noted, `The first Apollo space craft caught fire during a test on the launch pad. Three astronauts were killed, the nation was shocked and horrified, all the more because the screams and scrambles of the astronauts could be clearly heard'. After a brief delay in manned flights, the Apollo program resumed with strong public support; within 18 months, Apollo 11 landed on the moon. Fairlie contrasts the Apollo tragedy to the 1986 Challenger disaster. `The prevailing mood in America so panicked NASA that it took almost three years to send up another shuttle', he observed. `In 19 years between these tragedies, the idea that our individual lives and the nation's life can and should be risk-free has grown to be an obsession threatening to create an unbuoyant and uninventive society.' Taking risks is a normal part of our daily routine. The act of living involves minute-by-minute decision-making focused on survival through the practical management of risks. The act of breathing exposes each individual to the risk of infection while the act of crossing the road could almost be considered suicidal. We deal with these constant threats by observing simple rules of hygiene, safety or what may be labelled as common sense. The rules of community, designed to minimise risk in society, can at times lose focus and result in the imposition of schemes that have a far greater cost than the issues from which they protect. Effective management of risk, whether in the community or a business is about awareness and balance and the elimination of unacceptable risk. Risk cannot be eliminated from our lives or our working environment. However it can be managed if it is properly understood, monitored and controlled. The purpose of my presentation today is not to provide a comprehensive technical risk inventory but to capture the essence of risk and the application of management strategies designed to deal with it in a positive fashion. The basis of our differential financial reward system is risk. The key to successful management is to deal with the downside risks in such a fashion that the benefits of enterprise are not eliminated. The key question any investor must consider is `can the major risks assQciated with a venture be managed or eliminated while retaining a greater proportion of upside potential'. The answer to this question is the ultimate value an investor would assign to any project. In reviewing the relevance of risk to our industry the range of papers to be presented today provide examples of how management deals with specific components of risk. In each case the value of the business has been enhanced by the practical application of balanced risk management. The ultimate success of the industry depends very much on this concept as it also provides a public showcase upon which we are judged. Therefore, from all perspectives the effective management of risk is a cornerstone from which to build a stable and progressive mining industry.

Jan 1, 1994

By S H. Hyun, J W. Cho

Jun 19, 2024