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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

By J Canterford

Although we have access to a wide range of sophisticated process design and improvement tools in combination with a significant range of case studies, the mineral resource industry still manages to be plagued by the negative publicity surrounding operating plant failures because they were neither smart nor safe, together with proposed projects that fail at the first or second hurdle. The general public and the finance industry are generally totally uniformed about projects that ramp-up to name plate capacity on time and on budget and even more so when ahead of schedule and under budget. As the saying goes, good news does not cut the mustard.The following is a summary of the author’s sometimes jaundiced view about why metallurgical plants do not live up to their technical and commercial expectations. In no way should the summary be construed as a negative reflection on the skills of the metallurgical profession. Rather, it is to be taken as a positive acknowledgement of those skills and is intended to highlight some of the major considerations that need to be assessed as a potential project transforms into a sustainable technical and commercial reality.While a considerable portion of the summary is directed at developing hydrometallurgical flowsheets, the general principles are equally important to all aspects of extractive metallurgy.For convenience, the summary covers the following five basic discussion points – project, people, process, patents and politicians.

Aug 8, 2011

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 Espig D, Standish N

In the paper a stochastic model of the batch sieving procedure is presen- ted resulting in a system of ordinary differential equations to describe the time dependence of the mass fractions on the sieve surfaces being randomly influenced by sampling errors. The coefficients of the system can be interpreted as sieving velocities. Their dependence on the sieving con- ditions is discussed and a special type of functional relationship and methods are suggested to determine this function experimentally. Moreover the applicability of the approach is demonstrated by an example to evaluate the particle size distribution, if only the result of incomplete test sieving is known. For this problem a rough error estimation is performed.

Jan 1, 1984

After the minim operation, most raw materials that occur in the earth's crust require some form of processing or refining before they can be converted into a final end product. In the mineral industry these remarks apply to materials such as iron ore, bauxite, limestone, copper ore and many others that are found in Australia in large quantities. Processing plants for these raw materials operate more efficiently, however, if the feed to them is consistent in both physical and chemical characteristics. Such uniformity rarely occurs in nature so that some form of homogenisation, or blending, is required ahead of the processing plant. Bending also assists the mining operation itself by reducing; the need for selective mining and, by combining high and low grade materials, a more uniformly graded, commercially acceptable product can be obtained, thereby increasing the commercial life of a mine or quarry. Bed blending is the most efficient of the processes available, and following its development in the United States in 1905, over 100 plants have been installed, or are under construction, all over the world. The original process, the Robins--Nessiter system, has been the subject of continued improvements and refinements, so that economical capacities are possible from less than 100 l.t.p.h. up to 10,000 l.t.p,h. and beyond.

Jan 1, 1969

By L W. Palmer

"Evaluating the geological risk associated with ore deposits is becoming common practice in the mining industry. While geostatistical simulation is a useful tool for evaluating this risk, the effect of applying different types of simulation is less understood. For simulation of categorical variables like rock types, available methods perform simulation in fundamentally different ways. In this study, the geological risk relevant for informed mine planning is studied with two categorical simulation methods, PluriGaussian Simulation (PGS) and Sequential Indicator Simulation (SIS). Risk is expressed as a probability of repeated occurrence of lithological units in the same location across simulations. Significant differences are observed between the methods in terms of spatial distribution of risk. To identify the most plausible risk model, the input parameters at every step of both techniques are scrutinised. PGS and SIS inputs are classified as four parameters that are: fundamental to implementation of the methodfixed to enable comparison of PGS and SISdetermined by user interpretation, hence variablenormally optimised during application of PGS and SIS. The effect of parameter selection from categories 1 and 4 on the risk model is investigated using drill core data from a leucogranite deposit. A corresponding block model is created for assigning outputs from PGS and SIS. Risk models produced by either method are illustrated in a cut-out from the block model to enable bench-by-bench comparison. For PGS, risk associated with relatively rare lithologies is relatively sensitive to variation of parameters. Independent of the abundance of lithology, a location-dependent effect of variogram and vertical proportion curve parameter selection is observed, with risk increasing towards the deposit edge. Although SIS requires fewer inputs, single lithologies must be modelled in turn. Using small numbers of samples in the search neighbourhood, all risk models differ substantially. For larger numbers of samples, the risk models are similar. Overall it appears that the risk model produced using SIS is less sensitive to changes than PGS but further work is required to confirm this.CITATION:Palmer, L W and Glass, H J, 2014. Risk associated with rock type prediction using simulation techniques, in Proceedings Ninth International Mining Geology Conference 2014 , pp 217–228 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 18, 2014

By A B. Christie

REGCHEM is a geochemical database containing stream sediment geochemical analyses compiled from open file mining company exploration reports. The database contains data on over 21 000 samples that have each been analysed for several elements such as gold, silver, arsenic, copper, lead and, zinc.   REGCHEM is supported by GEOEXPL - a custom written computer software application which operates under Microsoft Access. The data can be plotted as maps using a geographic information system (GIS) package called MapInfo, which can incorporate data from other data sets such as mineral deposit sites from the geological resource map database, GERM.

Jan 1, 1994

The main features and recent developments in the processes of benefication and extractive treatments of tin ores are reviewed. The need for development of processes to recover fine tin, tin from low-grade complex ores and from hard rock resources is indicated. The progress in understanding of slag-metal interactions and developments of fuming processes on industrial scale is delineated. the processes and prospects of hydrometallurgical and chlorination methods are briefly indicated.

Jan 1, 1992

By Revy T

A testwork program aimed to improve the assaying of underground face samples established that for an Accelerated Cyanidation Extraction using the LeachWELLTM 60X catalyst, followed by an Aqua Regia finish (to quantify non-cyanide-extractable gold): ò Assay results (including the aqua regia finish) from a full set of samples from one underground face can be returned within four hours. ò The reagent dose to make the method simple and 'bullet-proof' is 8 gm LeachWELLTM 60X and 20 gm NaCN per 200 gm sample (30 per cent solids). Pulverising is to 90 per cent passing 75 micron (compared to the standard of 90 per cent passing 150 micron), and cyanidation is completed within one hour - however both might be further optimised. ò The LeachWELLTM/Aqua Regia results demonstrate that Fire Assays suffer from a significant nugget effect which makes the Fire Assay data relatively unreliable. ò Original costs, specific to Bannockburn (viz including an Aqua Regia finish), handling approximately 20 000 to 25 000 per annum is estimated to be $5.40, ie about one-third less than fire assaying. Optimising is further reducing these costs. It is estimated that the LeachWELLT"'/Aqua Regia assay procedure has reduced the probable error limits of any given assay of this ore from the range 0.74x to 1.36x for Fire Assay, to an appreciably smaller range of 0.90x to 1.11x. Thus for a cut-off grade of 1.60 g Au/t, samples with Fire Assays ranging up to 2.18 g Au/t have 25 per cent chance of being below cut-off, while samples with Fire Assays as low as 1.18 g Au/t have an equal chance of actually exceeding cut-off grade. This 1 g Au/t range in uncertainty is generally unacceptable for many practicalgrade/tonnage relationships. By contrast, using LeachWELLTM + Aqua Regia assays, the estimated corresponding limits are 1.44 g Au/t and 1.78 g Auk respectively - a far more tolerable 0.34 g Au/t range of uncertainty. Subsequent data has demonstrated that sufficient accuracy for grade control is achieved by Accelerated Cyanidation alone, further halving the cost of assays.

Jan 1, 1994

By K C. Corin, C T. O’Connor

In recent years it has been shown that the concept of using partial molar excess Gibbs energy (G̅ex) to explain the behaviour of collectors in the recovery of minerals can be usefully applied to explain flotation performance. Fundamentally this is because hydrophobicity of a mineral particle on which a collector is adsorbed may be strongly related to the fact that the alkyl chain associated with the collector behaves in the same way as any hydrocarbon would in an aqueous medium. This hydrocarbon-water system represents a classical non-ideal mixture, and such mixtures are quantified thermodynamically by determining the activity coefficient of the hydrocarbon moiety of the collector and hence its G̅ex in the mixture. It has been shown that G̅ex is a more rigorous indicator of the contributions of various alkyl groups of a collector than HLB (Corin and O’Connor, 2014) and was also able to explain aspects of froth behaviour (Harris and O’Connor, 2017) and hydrophobicity (O’Connor, 2021). The present paper is aimed at extending the above concepts in two different ways. Firstly, a study is undertaken of a range of results previously reported in which various reagents containing different alkyl groups were analysed in terms of their effect on contact angle and their performance as flotation reagents in terms of recovery. These results sustain the previous observations that there is a robust positive relationship between hydrophobicity as indicated by flotation recovery and contact angle and G̅ex of the alkyl group associated with the collector. Secondly, on the basis of the observation that increases in G̅ex are indicative of increases in the hydrophobicity of the mineral particle-collector aggregate, a study was undertaken to examine the effect of ions typical of electrolytes in water as well as the effect of the presence of alcohols and of pH on G̅ex of the collector alkyl group. In the former two instances the absence of any correlation between G̅ex and recoveries supported the proposition of the respective authors of these studies that the major effect of these electrolytes and added alcohols may be on particle–bubble attachment rather than on the hydrophobicity of the mineral/collector in the aqueous system. On the other hand, the effect of pH on G̅ex correlated reasonably well with changes reported in the literature on the effect of pH on recovery and contact angle.

Aug 24, 2022

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 role of the mine geologist in a business perspective is self-evident to some, but to others it may be a new concept. All mine geologists need to know exactly how they add value to the business if they are to be successful. Alternatively, if they do not add value, then they will become redundant. This paper seeks to understand some of the contributing problems that hinder the mine geologist from operating in a business perspective. In doing so, a new context (for some) is proposed to aid the mine geologist and the operation gain greater value from geology. The proposal suggests how to ensure that the activities of our geologists are intrinsically linked to the business process that we are involved in. The mine geologist can and must play a pivotal role in the success of an operation. To do this, they must understand some principles of business such as:process, customer/supplier relationships, and organisational structure. Our geologists must know the business objectives, understand the product that the customer needs and use their geological skills to deliver the product safely, on time and to specification. As geologists, we can be instrumental in ensuring that the operational environment is structured in such a way that maximum value is realised, not only from the mine geologists but the entire site team. In doing so, mine geologists will realise their full potential in delivering the outcomes the business demand, and therefore be recognised as strong contributors to business success.

Jan 1, 2000

By I Canbulat, G Si, Y Duan, X Luo

The presence of unfavourable geological structures such as faults and dykes often can contribute to coal burst risk. Seismic events associated with rock fractures tend to cluster around these structures and it is important to understand the characteristics of seismicity for coal burst risk management. In an Australian underground longwall coalmine, two clusters of seismic activities close to the longwall face and within a section of the maingate roadway which was intersected by a major dyke were respectively identified. The induced seismicity in the dyke-roadway area was closely related to the longwall mining. These seismic events were located and the distribution of seismic events shows that more fractures were distributed on the inbye side of the dyke. The spatial-temporal changes of the seismic event locations delineate the fracture propagation as the longwall mined through the dyke. The frequency-magnitude relationship of seismicity was analysed and it was found that it changed significantly when the longwall was mining towards, through and past the dyke. The monitoring results demonstrate that because of the stiff dyke, the seismicity was intensified in the roadway section. It proves that the dyke promoted stress re-distribution and seismicity in its vicinity. More fractures were induced in the hanging wall of the dyke, whereas less strain energy was accumulated and released in the footwall of the dyke.

Nov 29, 2022

By P Hanna

Following the Busang fiasco, more detailed guidelines were appended to the latest revision of the JORC Code released in September 1999 (JORC, 1999). Although the definitions and terminology essentially remained unchanged, the additional information in the guidelines has highlighted a number of issues for consideration by geologists undertaking computer-based resource estimations. The three main issues are:Data Integrity û details such as drilling and logging techniques, sampling procedures, assay tests, site visits, data recording and aggregation methods need to be considered. Geological Interpretation û is the Competent Person applying the appropriate software interpretation to the deposit in accordance with the regional setting. Are the correct computer-based tools being applied and are they producing the desired result (without compromise) to the satisfaction of the Competent Person? Modelling Technique û the importance of the relevant experience of the Competent Person not only in regard to the geology, but also with respect to the modelling algorithms and resource calculation methods of the computer software system involved. At the end of the day, it is essential that the Competent Person undertake a reality check on the resource estimation itself. They should also check that the borehole spacing is in accordance with the level of continuity for each critical parameter (such as structure, grade, impurities, etc) for which the resources are categorised.

Jan 1, 2000

By M Wortley, J McKay, D La Rosa, O Guyo

It has been a generally held concept that crushing operations were, by their nature, too simple to benefit from the implementation of advanced process control. The commissioning of an OCS¬ expert control system and image-based oversize detection system, VisioRock, at the Pilbara Iron Tom Price facility are dispelling these notions. A constraint-based OCS¬ expert control system has been designed and commissioned on the high-grade crushing and screening plant along with a vision-based oversize detection system functioning on six product conveyor belts. To date, the expert control has demonstrated the ability to increase production by maximising dynamic constraint utilisation. Dynamic constraint utilisation is a concept developed by Rio Tinto Technical Services for effectively evaluating constraint-based control logic performance. The VisioRock system has been installed and configured and has been operating for a period of several months. Currently, Tom Price and Metso personnel are working to define correct oversize detection thresholds. Details of the plant implementation are discussed.

Jan 1, 2005

By S Jahn, M Noel, E M. Rykaart, M Pau

Three soil cover test areas were constructed on waste rock backfilled into the Lichtenberg Pit, near Ronneburg Germany. A fourth, uncovered area was included as a control. Each test area measures 50 m by 65 m, and was constructed using full-scale equipment and construction practices. Extensive material sampling and testing was included as part of the construction. Devices were installed in each plot to monitor meteorology, infiltration, run-off, interflow, soil moisture, soil temperature, and soil pore gases. Boreholes were completed in each area and instrumented for temperature, pressure and pore gas sampling to a depth of approximately 60 m. Data from the monitoring instruments have been collected since July 2000, and have been comprehensively analysed and modelled on two occasions. The paper presents an overview of the test area design and instrumentation and the results of the two comprehensive data reviews. The reliability of the various monitoring methods is discussed and experience with several innovative methods is reviewed. The difficulties encountered in modelling the data set using common soil physical models are discussed.

Jan 1, 2003

By D K, S Freij, A Rossiter, X Han, B Feng

In mining operations, the removal of overburden to expose the ores is achieved by rock blasting using ammonium nitrate based explosives, eg ammonium nitrate-fuel oil mixtures, commonly known as ANFO. However, ammonium nitrate can react with pyritic shales that are often found in many mines, leading to premature detonation or spontaneous explosion. In order to minimise the occurrence of spontaneous explosion, the reactivity of the shale in a mine must be assessed. This will provide a better understanding of blasting risks and thus will improve the safety and the cost efficiency of blasting through the selection of appropriate explosives. In this study, shale samples were collected from different locations in Western AustraliaÆs Mt Whaleback iron ore mine and geochemically characterised. The reactivity of the shale samples towards ammonium nitrate and ANFO was investigated using a combination of large-scale firing range tests and laboratory isothermal reactor tests. Results of the firing range tests show that the reactive ingredients of the shale are the limiting factor for the reactions between shale and ANFO. Based on the firing range test results, further isothermal reactor tests were conducted to investigate the reactivity of shale samples towards ammonium nitrate under controlled conditions. Analysis of the results from the firing range tests and the isothermal reactor tests shows that there are correlations between the reactivity of shale samples and several geochemical characteristics such as sulfate, sulfur, ferrous and zinc content.

Jan 1, 2005

By J A. Cowburn

The high intensity zone within the Jameson Cell is the downcomer. It is largely external and separated from the flotation tank. This, together with operation of the downcomer under vacuum, rather than at elevated pressure and the absence of moving parts, allows ready access to the high intensity zone for measurement and analysis. Experimentation was conducted allowing measurements of recovery for residence times of between 20 milliseconds and ten seconds within the downcomer of a Jameson Cell. The affect of aeration rate on the recovery of different particle sizes was also studied.

Jan 1, 2005

Subsurface development requires some geotechnical conditions and challenges. Most of then are related to the compatibility between tunnelling system and surrounded ground conditions, and design criteria. Design criteria usually involve lining pressure and ground control of displacements. In order to fulfil these requirements, geotechnical parameters have to be obtained as well as construction aspects have to be taken into account for predicting the tunnel behaviour. The Brasilia Metro is presented as a case history illustrating the geotechnical conditions and challenges for its implementation. It is 42 km long, including tunnels excavated in collapsible porous soils by the New Austrian Tunnelling Method. The Brasilia porous clay presents some characteristics, which may lead to large deformations due to structural collapse. Empirical methods were calibrated for collapsible porous soils and then applied to predict tunnelling-induced settlements. Settlements due to soil structural collapse modify completely the expected settlement profile, increasing their values from the tunnel crown to the ground surface. Consequently, surface settlement trough volumes were also greater than the ground losses around the tunnel. In this case history, structural collapse of porous soils played an important role and must have been taken into account to predict correctly the settlement trough and profile. Numerical simulation has shown that settlement magnitudes due to structural collapse are strongly dependent on the soil stiffness reduction after collapse and the extent of the collapsible zone.

Jan 1, 1999

Safety bulletins and stickers issued for the paste backfill plant at Cannington read as follows: æCannington Paste Fill Plant, First of ItÆs Kind in AustraliaÆ. We could even dare to state that the Cannington plant is different than any other paste backfill plant in the world because of the overall design, plant equipment and underground delivery. However, one thing to be certain of is, the paste backfill plant works as designed and a pump is not required to deliver paste underground given the general plant arrangement at Cannington. The past two years have been a process of evolution to design and construct the plant and make it work. This paper will describe the paste process using full mill tails along with placement of cemented paste underground. Discussions will include rationale of fixed plant selection along with various control requirements. BHP World Minerals recently commissioned its paste backfill plant in December 1997. Cannington is placing full mill tails underground via two surface boreholes that deliver either to primary or secondary stopes.

Jan 1, 1998