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By J Butler, N Patel, S Narendranathan, S Rastogi

The Yallourn Mine (YM) commenced mining of brown coal in the 1920s under operation by the State Electricity Commission of Victoria (SECV), prior to it becoming privatised in 1996. The present owners of the YM, Energy Australia Yallourn (EAY), acquired the site in 2000 and intend to continue operations until scheduled closure in 2028. Brown coal extracted from the YM is fed into the Yallourn Power Station which supplies approximately 22 per cent of Victoria’s electricity. Water within the YM is collected and stored in the Township Field Fire Service Pond. Water levels within the Fire Service Pond (FSP) may fluctuate considerably depending on the requirement for storage at the site. With due consideration to the stability performance of mine batters adjoining the FSP, the authors performed slope stability assessments to evaluate the risk and consequence of batter instability during the potential pond filling as it approaches the ‘critical pool’. The critical pond is defined as the level at which the driving forces (destabilising forces) are at their greatest and the resisting forces (lake forces, friction) are at their lowest. This assessment was undertaken using the Mine Geotechnical Risk Index (MGRI) approach.

Aug 2, 2023

The problem of comparison of island arc's andesites in terms of petrochemical data is exa- mined. It is definitely established that only two main factors exist controlling the petroche- mical variety of the Kurile arc's andesites.Ori final multivariate statistical technique and computer software are used to extract these fac- tors. It is shown as well that the chemical com- position of igneous rocks depends on the type and structure of the Earth's crust. The follo- ~cing interpretation is proposed for the two factors describing petrochemistry of andesites: the first one is the depth to the Benioff seis- mofocal zone and the second one is supposed to indicate the position of the peripheral magma chambers. The basic trends of variations in the chemical composition components depending on the changes in the controlling factors are de- Tcnnined.

Jan 1, 1987

A new lead refinery with a. capacity of 230,000 tons per year com-menced operation at*Port'Plsie in October, 1959. This plant' superseded the refinery which had operated from 1933 with the advent of thecontinuous lead refining process. The incorporation of new equipment following local metallurgical developments, together with the overseas demand for lead of extremely low antimony content, created difficulties in operating the original plant. The new refinery project was under-taken to cover this disability and to gain the full advantage of the new processes.Desilverising and softening are carried out in units identical in size to those used previously. Metallic'zinc is now recovered from the entire output of desilverised bullion by vacuum distillation. Final refining is then carried out by batch'treatinent with caustic soda yield-ing lead of purity previously unattainable at Port Pirie.These two processes have replaced continuous dezincing by oxidation, a high temperature process which caused large quantities of lead and antimony to be recirculated. As the final stage is a .batch process the product composition can be.checked before casting. Individual batches can be adjusted to produce special alloys to,consumer's specification.Improved casting equipment has allowed the quantity production of pigs of good physical characteristics either as 56 lb bars or 2000 lb pigs. This, together with the high purity of the lead, has assured the B.H.A.S. position in world markets.Automatic control systems have been extensively employed particularly on the vacuum dezincing unit.The anticipated financial benefits have been achieved mainly by a reduction in the tonnage of recirculated materials, a smaller labour force, and reduced maintenance requirements.

Jan 1, 1963

In this, the centennial year of The Institute, it is appropriate that the history of the Institute in New Zealand be recorded. I am indebted to John Dew, compiler of the centenary publication æMining People A Century - Highlights of the First Hundred Years of The AusIMM 1893 - 1993Æ, for many of the early historical references in this paper. In July 1892 the Amalgamated Mining Managers' Association of Australasia held its annual conference in Ballarat, Victoria, Australia, when it was suggested by the delegate from Broken Hill that the time had arrived for the establishment of an Australasian Institute of Mining Engineers. Resulting from this meeting at Ballarat, a Provisional Committee was formed at Broken Hill with the object of forming The Australasian Institute of Mining Engineers having the following objectives. To promote the arts and sciences connected with the economic production of the useful minerals and metals, the welfare of those employed in those industries by means of meetings for social intercourse, and the reading and discussion of professional papers with the circulation by means of publications amongst its members and associates the information thus obtained.

Jan 1, 1993

By N B. McCaffrey, V Glenn, C Johns, P D. Erskine, A T. Fletcher

"Underground coal mining is the dominant method of extracting thermal and coking coal in the southern and western coalfields of New South Wales. Monitoring mining-related subsidence forms an important component of environmental impact assessments and subsidence management plans, particularly when there are conflicts between the interests and requirements of mining and environment and community groups. However, there are few specific guidelines for monitoring the impacts of subsidence on terrestrial and aquatic ecosystems, leading to inconsistent policy approaches and highly variable abilities of monitoring programs to accurately detect biological change.This paper highlights the use of a conceptual framework to guide the development of a long-term ecological monitoring program at an underground coalmine in the Western Blue Mountains, New South Wales. Two pilot studies are described: determining the level of observer agreement to assess the condition of a vulnerable tree species (Capertee Stringybark) comparing field sampling methods for detecting a rare heath shrub, Epacris muelleri, using a power analysis to determine sampling intensity requirements.These examples demonstrate that investment in initial pilot studies to test different monitoring approaches can have long-term benefits for stakeholders by more confidently being able to detect potential impacts.CITATION:McCaffrey, N?B,?Glenn, V, Erskine, P?D, Johns,?C?and Fletcher, A?T, 2014. Detecting long-term ecological impacts of subsidence from underground coal mining – a tale of two pilot tests, in Proceedings Life-of-Mine 2014, pp 139–152 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 16, 2014

By D Fergusson, J D. St George

Highwall stability is a major consideration in optimising opencast mine geometry. It involves assessing the risk of those slope failures that are large enough to have significant cost, safety and/or operational implications. These risks are then balanced against the value of the resource to arrive at an acceptable slope design. Load-deformation models (commonly referred to as ænumericalÆ models) of slopes provide a powerful tool in this decision-making process since they can be verified well before slope failure occurs. This gives the slope designer increased confidence in reviewing designs during excavation, potentially allowing early revision of pit geometry to either increase or decrease safety margins as appropriate. However, these models are not always adopted as they depend heavily on an appropriate choice of constitutive model and material parameters.   A preliminary load-deformation model of a 170m highwall in Solid Energy North (SEN) OperationsÆ Awaroa 4 opencast coal mine in the Rotowaro Coalfield has been prepared. This uses a strain-dependent constitutive model based on laboratory test results, strength parameters developed by SEN and excavation monitoring data. The laboratory testing has included triaxial compression tests on large-diameter fractured samples to characterise the stress-strain response of the closely-jointed soft rock masses that exist in many parts of the mine. Data from the monitoring of a 25m cut made during excavation of a haul road has been used to refine and verify the constitutive model. The resulting highwall model has predicted highwall crest movements corresponding to the excavation of each bench, for comparison with monitored values. Key model outputs are total horizontal movements of about 0.5m near the highwall crest and shear strains of 0.5-0.7% at the locations of potential bedding-parallel shear planes underlying the highwall. Most of the movement is expected to occur as creep rather than as an immediate response to excavation.

Jan 1, 2006

This Institute, by nature of its charter, draws on various persons in the mining and metallurgical world of Australasia for its President from year to year, and consequently when the presidential address is given by one of these people the topic. which they generally select is a topic to which they are accustomed and on which they are able to speak with authority.As most of you know, my prime object in life has been concerned with steelmaking, so tonight you can steel yourself to the thought that you are going to be spoken to about steelmaking.Even if that were not the case, and were I not particularly interested in steelmaking, I think it would be appropriate to look at steelmaking in a broad sense on a basis of pure metallurgical interest, because the steel industry is going through as big a revolution today as it went through something over one hundred years ago when Bessemer made a theory become a fact.Bessemer, and as the Americans prefer to think Kelly, separately conceived the idea of blowing cold air through molten pig iron, and, contrary to the then general belief, this did not result in cooling of the metal but succeeded rather in heating it, and in burning out of the rather crude pig iron the impurities which prevented it from becoming a ductile metal.For many years before this, steel had been made in a very small painstaking way by what was known as the crucible process. Benjamin Huntsman is credited with having developed the crucible steel making process to a stage where it could make a reliable and trustworthy product, but he...

Jan 1, 1961

The Karangahake gold-silver deposit is located 11 km west of Waihi in the southern part of the Hauraki Goldfield. Historically it was the second largest bullion producer in the goldfield with a past production (1882 - 1944) of 126.712 tonnes of gold-silver bullion (Au:Ag ratio of 1:3.3) from 1 142 315 tonnes of ore grading 27.4 g/tonne gold equivalents.

Jan 1, 1987

It is no longer satisfactory to assess the value of a coking coal on its intrinsic properties alone; its value depends upon its behaviour as a component in a blend. No single test can be used to make this assessment, it can only be made by carrying out a suite of tests. The quality parameters which are considered desirable, and which have widespread acceptance, have been discussed and their application to the blending of coals from New South Wales and New Zealand has been reported and discussed. Blending can be utilised to offset deficiencies, or capitalise on advantages, of the individual coals making up a blend. Coals can be blended, which alone are poorly, Coking, but which have compensating features. Blending also allows better exploitation of coking coal reserves. Several applications of blending have been reviewed with regard to coal producers and exporters, as well as coal users. The possibility of extracting a coking coal fraction from fuel coals is discussed. Blending systems and the coking of coal are also briefly reviewed.

Jan 1, 1971

By Faidel VV, Yushina TI, Yagodkina NG, Yatsimirsky AK, Chanturiya VA

Among the problems of the flotation of sulphides by the thiol collectors is the dependence and varieties of the flotation starting with the time and oxygen contents in the slurry. For sulphides, the flotation stage follows after the electrocatalytic oxidation of the collector with oxygen on the surface of the conductor minerals. The necessity of the oxygen for sulphide flotation (Plaksin and Bessonov, 1957) is in accordance with a corrosion model of a collector surface sorption (Salamy and Nixon, 1954). As Golikov and Nagimyak (1961) showed, the sulphides possess catalytic activity which provides the autoxidation of the xanthates in the sluny to the dixanthogen. This stage can be rather protracted, which limits the speed of the total process. Disulphides constitute important collectors for the sulphide flotation and the optimal degree of the xanthate oxidation is about 20 per cent for different ores (Abramov, 1978) or, following Chanturiya and Nazarova (1977) the surface compositions for various sulphide ores are different and an optimal oxidation degree is variable from five to 25 per cent according to the ore nature. The optimisation of the surface composition is possible by application of the dixanthogens, or by a partial chemical, electrochemical, or catalytic oxidation of xanthates (Desains, 1847; Schall, 1896; Vigdergauz, 1989). According to Rand (1977) and Vigdergauz (1991) sulphides possess different catalytic activities for oxygen electroreduction. In neutral solutions, for example, the following decrease in the order: FeS2 (Fe,Ni)9S8 CuFeS2 FeS; Cu5FeS4 Cu2S; PbS (Vigdergauz, 1991). For the cases of low catalytic activities of the sulphides, the preflotation oxidation of xanthate could be useful to optimise the process kinetics.

Jan 1, 1993

A great range of contacting equipment is used in solvent extraction. However, a tower filled with a regular packing offers many advantages in the direct extraction from slurries. A study was made of the flow of a dense slurry through a packed tower in which the continuous phase was kerosene. The grid type packing, which was preferentially wetted by the slurry, had slats inclined at an angle of 30¦, to the horizontal. On the sur- face of the slats there were uniformly spaced longitudinal indentat- ions. These were of a height slightly less than the film thickness and divided the slurry discharging from the bottom of the slats into a number of uniform streams. When slurry entered the tower it was distributed by means of a troughs and weirs type of distributor. Because of the relatively high slurry velocities that occur at the entry region, it was necess- ary to have the distributor and the first two grids above the solvent level. The interface at the bottom of the tower was located at the mid-point of the bottom grid, so that the slurry entered the interface as a continuous film across the full width of the slats. Using the above system, stable flow with low entrainment was achieved at slurry flow rates of 3.4 mis/cm/sec. This would be equivalent to a flow rate of 177 gallons per minute through a tower of cross-section 4 ft 4 in. by 4 ft 10 in., or 1200 tons per day of solids of specific gravity 2.6 when the pulp density was 65 per cent. Previous tests indicated that a total tower height of about 30 ft would be required for a recovery of better than 99 per cent.

Jan 1, 1969

By Fletcher A. E W

Ever since it made its debut in 1962, in the form of a Robbins 31R, the raiseborer has become an accepted tool in the mining and civil construction industries. The first raiseborer to be used in the Witwatersrand goldfields made its appearance in 1968. This was a Robbins 42R which could raisebore 185m deep holes to 1,22m diameter. From 1968 to 1973 capability increased with the introduction of first the 61R, then the 71R and finally the 83R, which could raisebore 610m deep holes to 3,66m diameter. This created a demand for larger holes but the cost of bigger, more powerful machines requiring larger, stronger drill pipe, cutters and other accessories was prohibitive. To avoid replacing existing models such as the 71R, and in order to increase their capability, the concept of reaming in two stages sequentially was developed jointly by a German drilling equipment manufacturer, Wirth, their South African subsidiary, Transbor, and a local contractor, Rocbor Raiseboring and Mining Contractors. The result, the Sequential Reaming Head, proved most successful and existing machines, normally limited to 2,44m diameter holes, could now ream to 3,66m diameter. This created a demand for even larger holes. In order to maximise the use of the sequential reaming head to meet this demand the HG330, and subsequently the HG330SP raiseborer were developed. Using a 4,26m/6,02m cutting head, these machines have raisebored holes 1000m deep in hard rock. The raise- boring of the first major hole to be excavated by this combination, the 484m deep x 6,02m diameter surface shaft at Premier Mine is described. Reference is also made to six other shafts which have been completed or are under construction.

Jan 1, 1987

By J M. F Clout

Geological, textural and mineralogical classification of iron ores is routinely conducted by mine and exploration geologists on reverse circulation percussion, blasthole cone and bulk samples for grade control, defining ore and waste, determining lump:fines ratio and predicting downstream processing characteristics. Classification is based on physical hardness, colour, streak and other visual characteristics. However, logging is generally restricted to the five to 20 per cent of chips above about 2 mm. This means that most of the sample is too fine to be reliably logged for anything but colour or streak and the textural types must be inferred from other information. A recently developed software package called æRecognitionÆ allows automated identification and classification of iron ore textural types and gangue on a particle basis in polished section down to 0.01 mm using processed digital images. It is not designed to be used as a routine logging tool, but is applicable where higher definition is required at the resource evaluation stage on selected percussion, drill core or bulk samples. æRecognitionÆ processes data obtained after optical image analysis of fine iron ore samples. It contains several parts, like æRecognitionÆ, æCompositionÆ, æLiberation by Total IronÆ, æLiberation by PhasesÆ and æStatisticsÆ, which allow vast and diverse information to be obtained about the iron ore samples being studied. Identification and classification of the textural type of each particle is performed according to the CSIRO-Hamersley Iron Ore Group Classification Scheme. The recognition procedure encompasses a good knowledge of different ore types and a logical knowledge tree, managing fuzzy boundary problems and the potential for a few different ore types in the same particle to be considered. This new technology introduces strict criteria to make the process of identifying particles more objective. Automated recognition standardises the identification procedure and significantly saves time. It enables users without a strong background in mineralogy to perform accurate texture identification. The æRecognitionÆ package has a modern user-friendly interface and Word compatible output. The combination of all the features mentioned makes the package a convenient tool for detailed studies of fine iron ores.

Jan 1, 2005

By O Rojas

The Telégrafo copper – gold deposit is located in the Centinela district of the Antofagasta region in northern Chile. Telégrafo is a porphyry copper deposit of Eocene – Oligocene age which has a total mineral resource in measured, indicated and inferred categories equal to 2.6 billion tonnes with an average grade of 0.38 per cent copper.Currently the project is in the prefeasibility study phase, including an infill drilling campaign to improve the knowledge of the deposit that should result in an improvement of the mineral resource classification. In this context was decided to review the classification criteria in order to optimise the drill hole density necessary to support the project.This paper presents an application of conditional simulation to evaluate the risk related to drill hole spacing, using a geostatistical approach that mimics the process of evaluation of resources from the perspective of geological modelling and grade estimation. The first step of the approach is the generation of conditional simulations using the available samples to generate several plausible scenarios of the deposit in terms of copper grades and geological units. These scenarios are considered as the unknown reality of the deposit and sampled by synthetic drill holes in order to replicate the geological model process and copper resource estimation. In this way it is possible to establish differences between the possible scenarios and the generated resource estimation models for several simulated drill hole spacing alternatives. These differences or errors can then be quantified in terms of estimated mean, metal content and tonnage over different production volumes.The resulting errors were useful in assisting the decision making process related to the design of drill hole spacing for each category of mineral resource in the Telégrafo project, and to redistribute the budget associated to the drill campaigns for the next stage of the project.

Aug 22, 2011

By G F. Brent, R D. Hart, C Carr, F Felipe

In underground operations, where copper, gold and other metals are mined, the open stopes can be backfilled to stabilise surrounding workings. This fill may consist of tailings from the processing plant, usually mixed in slurry with a binder such as ordinary Portland cement (OPC). Extensive use is made of tailings in OPC-based paste fill, cemented hydraulic fill or cemented aggregate fill applications. A large underground operation such as the Mount Isa Copper Operations utilises over three million tonnes of backfill per annum. Geopolymers offer an alternative binder system with significant environmental advantages over OPC. Geopolymers are formed by polymerisation of aluminosilicate precursors in an alkali medium. They generally form products with superior strength characteristics as well as increased resistance to degradation, particularly under acidic conditions. Geopolymers have lower carbon dioxide emissions associated with their manufacture than OPC and offer further potential advantages, such as the use of less water and more waste materials. The application of geopolymers to weak material systems such as mine backfill has not been widely studied. The aims of this investigation were to assess a range of Australian mine process wastes for suitability as feedstocks in fill applications and to construct a range of these cemented minefills using a geopolymer binder. The physicochemical characteristics of each of the wastes are discussed as well as how they ultimately contribute to the geopolymer cement through direct replacement of OPC. Results from various tests on the candidate geopolymer fill formulations are presented and the potential of such fill formulations to replace OPC in mine backfilling operations is highlighted. The significant potential contribution to reducing greenhouse gas emissions from the use of geopolymer-based mine backfill across the industry is noted. Conversion of a single mine, such as the Mount Isa Copper Operations, is shown to match the reductions in greenhouse gas emissions due to the current total installed photovoltaic electricity generation capacity of Australia. A similar examination of wastes available to a gold mine could potentially yield new binders for use in established or new fill systems.

Jan 1, 2007

By L Rattmann, T Katz, J B. Pateiro-Fernßndez

Carbon capture and storage (CCS) is expected to become one of the main technological instruments for mid-term reduction of CO2 emissions into the earthÆs atmosphere. Besides the reduction of CO2 emissions into the atmosphere, the implementation of CCS would have various negative consequences, which are û if at all û only poorly covered in the current socio-political discussion. Taking into account all aspects of CCS, the outcome of a comprehensive and conclusive assessment of CCS against the background of the sustainable development concept is uncertain. When assessing the overall impact of CCS in a holistic approach, a variety of aspects with effects on sustainable development are affected. Besides economic issues, various other effects of implementing CCS should be taken into consideration. These include for example additional costs for CCS facilities and processes and a decrease in powerplant efficiency due to high energy requirements of capture processes, and various ecological and societal aspects, such as higher demand for combustible, resulting in faster depletion of reserves and higher land and water use and the provision of jobs along CCS technology chain. This paper presents an approach for a structured sustainability assessment of CCS based on the multi attribute decision-making (MADM) method analytical hierarchy process (AHP). The functioning of the presented methodology is exemplified at the case study of a German coal fired powerplant.

Jan 1, 2009

By F M. Weir, M Fowler

The design of excavations in rock must, implicitly or explicitly take into consideration the influence of small- and large-scale geological structures. For most sites the complexity of a fractured rock mass is best captured using a 3D fracture system model based on field data. A discrete fracture network (DFN) approach involves stochastic modelling of the ‘smaller scale’, nondeterministic structures. For slope stability or tunnelling projects DFN modelling provides a valuable geotechnical tool for characterisation of a rock mass and identification of likely failure mechanisms.This paper presents a suite of the DFN modelling undertaken for the design of a large open pit in Australia. The proposed pit is to encounter a 160?m thick, high strength, sheared shale unit, which overlies a crystalline basement. DFN modelling was undertaken separately for both the shale and basement units. While the model inputs and development for each unit are briefly presented, the focus of this paper is on the various applications of the DFN modelling.A key advantage of the DFN approach for design studies is its probabilistic application to structural analyses and results. Multiple realisations of the same model were generated for both the shale and basement units, with the stability analysis carried out on each iteration. The generation of a large number of DFN models and analyses allow assessment of wedge volume, factor of safety and proportion of unstable slope for a range of conditions. The DFN modelling at the case study site was also utilised for a number of other purposes. For example, investigation of likely fault lengths in the shale unit and combined rock mass and defect failure. The development of this tool has been influential in improving our understanding of fracture networks for excavation design.CITATION:Weir, F M and Fowler, M, 2014. Rock mass characterisation and analysis for excavation design – a discrete fracture network approach, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 445–456 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

The non-renewable energy resources of Queensland comprise coal, petroleum (oil and gas), oil shale and uranium. Coal is widely distributed., and has been developed extensively both for export and for use within the State. Proven reserves total 5 390 million tonnes recoverable of coking coal and 5 580 million tonnes recoverable of non-coking; very large resources particularly of non-coking coal are still to be quantified by further drilling. Annual production is of the order of 20 million tonnes of coking coal, principally for export, and 6 million tonnes of non-coking, mainly for power generation within the State. Petroleum resources are meagre in com- parison with those of coal. Initial recover- able reserves of liquids (mainly in the now substantially depleted Moonie Oil Field) totalled only 4.2 million m3. Initial recover- able reserves of gas (mainly in the western Surat and Bowen Basins) totalled 7 800 million m3. Annual production is of the order of 64 thousand m3 of liquids for refining in Bris- bane, and 268 million m3 of gas mainly for production of fertiliser and for industrial and domestic heating, in Brisbane. Prospects are fair for the discovery of additional reserves. Two deposits of oil shale are potentially of economic significance. The Rundle deposit at The Narrows in central Queensland has the

Jan 1, 1979

By Fennell B

A process for the recovery of cobalt from a speiss produced at Sulphide Corporation is presented. The speiss is leached in oxygenated sulphuric acid to dissolve the metallic iron at a pH of around 4. The resultant iron (11) is subsequently oxidized in the leaching vessel and precipitates as goethite. Acid is regenerated in the precipitation allowing dissolution of further speiss. Subsequent to the conversion of most of the iron in the speiss to goethite, conditions become sufficiently oxidizing to dissolve cobalt. Cobalt is not co-precipitated under the leaching conditions, yielding a pregnant solution containing the cobalt and some iron (11). The principal advantage of such a process is the significantly lower acid consumption over that obtained by complete dissolution followed by selective precipitation. An impure product of cobalt hydroxide can be obtained from the pregnant solution by neutralization.

Jan 1, 1983

By S Maritsa, E K. Chiwandika, S M. Masuka

The iron and steel industry is experiencing an increase in the use of iron and steel commodities within societies, decarbonisation pressures, depletion of high iron ore grades and high energy consumption. This necessitates scrap metal recycling, low-grade ore utilisation using the induction or electric arc furnace to achieve the global target of net zero CO2 emission. The available highquality scrap metal cannot sustain the steel industry but the world has unused hematite-goethite ores. It is the aim of this research that this resource be utilised using the induction furnace to sustain the steel industry in an environmentally friendly manner. Indurated pellets prepared from the hematite-goethite ore, 5 wt per cent limestone and 5 wt per cent coal addition were smelted in the induction furnace at 1350 ± 50°C with 25 mins holding time. The effects of basicity and carbon content were also investigated to optimise the smelting parameters. The results showed that the careful control of the basicity, and iron-to-carbon ratio maximised total metal recovery. The optimal basicity ratio was determined to be 1.3 and a carbon to iron ratio of 1.4 achieved a total metal recovery of 73 per cent. The metal recovery was closely related to the estimated slag melting temperature. The basicity ratio of 1.3 achieved the lowest slag melting temperature estimated to be around 1380°C based on the CaO-SiO2-Al2O3 phase diagram. The recovered metal had a comparable chemical composition and microstructure to that products from an ITmk3 furnace.

Jun 19, 2024