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By D M. Frantois-Bongarton

Variograms can be powerful tools for the analysis and control of process streams and their sampling. Their uses and proper utilisation have been described somewhat unclearly to date, and their limitations and precautions of use are too rarely mentioned. The general meaning and properties of the variogram tool and its use in geostatistics are therefore reviewed in details to derive a critical view of its proper use for process control: what to expect from it and what it cannot deliver and which uses are illusory or potentially misleading. A summary of GyÆs seminal work accompanies this essay to put the concepts into historical perspective.CITATION:Frantois-Bongarton, D M, 2012. Review of variogram properties and remarks on its use in process control, in Proceedings Sampling 2012 , pp 175-180 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 21, 2012

The operations management system at Olympic Dam has evolved over a two-year period to the state described in this paper. This evolution has been driven largely by the requirements of the recent expansion of the Olympic Dam operation from three to nine million tonnes of ore per year. Such a change process demands an holistic approach to mine management and several techniques have been employed including XPAC, Mine Works Planner as well as a basic philosophy of æjust-in-timeÆ completion. The philosophies, software and tracking mechanisms for managing a large tonnage operation are described, outlining a fully integrated scheduling system from shift to shift detailed activity planning to a 20 year production plan. Moreover, the vision of production exceeding the current limit of nine million tonnes means that there are to be further developments to this state-of-the-art system in use at the Olympic Dam mine.

Jan 1, 2000

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 McIntosh A. H, Torlach J. A

Since the last paper on mining methods was presented to the Annual Conference of the Australasian Institute of Mining and Metallurgy in 1:960, numerous advances have been made in drilling and blasting techniques at Mount Morgan. This paper describes the drilling and blasting methods being employed in the open cut. The change over to track mounted percussion drills for all types of primary drilling is almost complete and new techniques such as detergent drilling and pressure loading of ANFO are being applied successfully.

Jan 1, 1965

By Wittenberg J. C, Reid A. F

A method is described for the rapid and effective production of polished section mounts of ore and mineral particulates to the standards required for automated image analysis. This requires mounting without segregation of particles by mass or density, and it is also preferable to avoid having particles in contact so that they can be recognised as individuals. To achieve this, the particle samples are first split to an appropriate degree in a rotary riffle, and the sub-sample mechanically diluted and thoroughly mixed with an inert filler of the same size range as the particles. Just sufficient epoxy resin is added to make the mixture fluid. During setting, the ore particles are mechanically supported by the inert filler particles, thus maintaining the particles in a random three-dimensional distribution. A rapid two-stage grinding process, based on the successive use of 600 mesh silicon carbide and 1200 mesh (10 um) corundum on cast iron plates, is followed by three stages of mechanical diamond polishing on cloth laps. Hand polishing is entirely avoided, as is the use of papers.

Jan 1, 1984

By Halvorsen N

For mining medium-hard materials on the surface, "Continuous Surface Miners" have been employed for some years. The latest generation surface miner extends the performance of this type of machine to the point where the same cost efficiencies can now be achieved in medium-hard materials as has been achieved in softer materials by machines such as the bucket wheel excavator. The paper explains briefly the technology of the Krupp Surface Miner (recently released to the market) and develops the costs of ownership and typical operating costs. Comparisons are made between a shoveLtruck system and Krupp Surface Miner (KSM) systems based on both truck and conveyor transport systems. Further benefits of mining with the KSM, such as environmental, selective mining and improved product reovery are discussed briefly. The equipment is now available to mine semi-hard materials (with compressive strengths up to 60MPa) on a continuous basis and reap the benefits which continuous systems can deliver. All new and existing open cut mines should review their costs with regard to this technology.

Jan 1, 1990

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

By Grey CA

Any economic evaluation of a lead-zinc mining project requires the estimation of net revenue per tonne of concentrate at the "mine gate". The value at the mine gate equals the Net Smelter Return minus all realisation costs. The paper develops a simple predictive model for Net Smelter Return based on metal prices.

Jan 1, 1990

By C Thompson, D Connelly

The history of mill liners has evolved over time and this paper tracks the changes and development of liner technology. It provides an overview of the primary types of liners, the design and the materials of construction. The design of a mill liner is driven by application, materials of construction, casting technology and handling issues. The choice of solid steel, grid liners, rubber or composites and magnetic liners is based on many factors.The methods used for monitoring wear and predicting eventual change out time are many and varied. The contribution of discrete element modeling (DEM) analysis in predicting wear profile is discussed.Mill trajectory and DEM software programs are used with great effect to predict the effect of lifter height, face angle, high low lifters or mill speed. In the field, trial and operational experience is used or improvements/design concepts at one operation are applied to another. Broken mill lifters, accentuated wear and other problems can be better understood using hardness testing, chemical analysis and photo micrograph analysis of pearlitic or martensitic structure along with fracture face observations. This forms a part of the typical root cause analysis. However given correct and sound liner and lifter, feed and discharge design media selection, and materials of construction, the majority of premature liner or bolting failure is normally attributed to incorrect operational methods such as excessive high ball to feed ratio, incorrect mill speed relating to lifter ball throw, incorrect media selection, "tramp" material entering the mill charge from upstream or recirculating process and understanding the specific mill operation in question.It is hoped that this paper will benefit mill operators who are faced with challenges of improving wear life and at the same time optimizing mill throughput and performance.CITATION:Connelly, D and Thompson, C, 2013. The selection design and application of mill liners for large wet grinding mills, in Proceedings MetPlant 2013 , pp 133-140 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

The extent of regional stratigraphic and structural geological mapping so far carried out in Australia is likely to be greatly overestimated by uncritical inspection of the latest authoritative geological map of the continent-that so ably compiled by the late Sir'T. W. Edgeworth David. Vast areas geologically coloured on this map are in fact known only from the most meagre field data, some of Which even include observations of distant views from which the so-called "geology" has been indicated in' reconnaissance reports.This applies to large areas in Cape York Peninsula; the plateau of Arnhem Land, and its margins except on the west where the Pine Creek mineral belt is better known; to the Desert Basin of Western Australia, practically the whole of the western half of the Northern Territory, much of east-central Western Australia, and northwestern New South Wales. Other vast areas are, more happily perhaps, left blank. It is true that prospecting parties have, at various times and with varying degrees of thoroughness, traversedparts of these little-known regions, often, however, in the search for gold or the.more obvious types of metalliferous mineral deposits and, furthermore, too often without leaving any written account of their examination, or with very sketchy details supplied. Unpublished geological surveys also cover some parts of these regions, but, on the whole, the picture we can draw of the regional deployment of rock masses in Australia is far less full than even David's map, with its obvious blanks, presents to us.Lest the practical mineral seeker among us should be inclined to place too much reliance on the prospecting to which I have referred.as giving him a straight hint of what country to keep out of, we may point to the recent discovery of a major sedimentary basin in the east KimberllilYs on which Dr. Teichert will have more to say. And that there are new metalliferous mineral deposits to be foundin parts of these little-known areas no one can doubt, for, after all, new discoveries are made from time to time in areas so well-known as the Victorian gold-fields. I take it then that regional geological mapping is a necessary concomitant of the further development of Australia's mineral resources-but I am not of the school that places it first on the list of priorities, and furthermore I believe that there can be a royal road to regional mapping-an inspired approach based on knowledge already gained and led to fruition by field surveys in key areas, by which there may be obtained a result giving a significantly close approach to actuality with only a fraction of the work that would be required for detailed field surveys on a systematic basis. I believe that a policy of rapid reconnaissance of such a type should be adhered to, especially in view of present deficiencies in numbers of geologists available for all purposes in Australia. The details that must eventually be sought can, I believe, be filled in later as the whole country becomes more developed and amenable to detailed surveys.

Jan 1, 1950

This paper discusses the social and economic impact of mining, and in particular goldmining, on New Zealand. The range of topics covered and their complexity has confined us in this paper to highlighting the main points of concern û a detailed report is under preparation. A major problem in undertaking this study was the lack of hard data on important environmental, economic and social issues and if there is to be effective planning in the area of natural resource use this situation must be rectified. The following conclusions were drawn: Goldmining was very important in shaping New Zealand's early social and economic development, providing wealth, employment and impetus for social change.Foreign investment and technology has been an essential element in New ZealandÆs economic development.Mining is a small industry at present by this must not be allowed to obscure its potential to broaden New Zealand's economic base and provide foreign exchange.With modern methods, development of mineral resources and environmental protection are not incompatible but certain unique and irreplaceable areas must be preserved.There are problems in evaluating mining and other projects because different groups hold different values, and arguments often hinge on the valuation of costs and benefits rather than the technical aspects of the analysis.Mineral exploration is a high risk business and the potential returns must be sufficient to attract capital if New Zealand's mineral resources are to be developed.A resurgence of goldmining will clearly have obvious benefits for Waihi but the local community must plan carefully for their future. New Zealand will also gain valuable foreign exchange required for higher levels of economic activity.

Jan 1, 1981

According to the data provided by the most recent European Survey on Working Conditions, roughly 25 per cent of the European working population is exposed to mechanical vibrations for no less than one quarter of the work shift duration, while around ten per cent are exposed for the entire work shift. The occupational exposure to whole-body vibration (WBV), in particular, represents a major health risk in mining, quarrying and civil excavation activities. In accordance with European Directive 2002/44/EC, the latest version of the Italian law on physical risks has recently confirmed the possibility of using relevant literature data on vibration magnitude in order to evaluate personal occupational exposure (vibration database or data provided by the manufacturer). Still the alternative option, based on field measurements, represents the most appropriated method of risk assessment, as it accounts for the actual operating condition at the workplace; actual operator and vehicle under investigation and specific working cycle. The article discusses the vibration measurements taken on a number of heavy machinery (excavators, loaders, trucks, dumpers, etc) employed for talc extraction in a mine located in Sardinia and the resulting personal exposure for the drivers. The assessment was carried out in accordance with the specifications of ISO 2631-1 and EN 14253.

Dec 6, 2010

By Flavelle IV

A survey is made of changes in the technical status of a number of western world copper extraction and refining operations over the past 20 years. Specific developments in pyro- and hydro-metallurgy and refining practices are identified together with factors in the changing environment of the industry which has influenced their adoption. Nickel extraction and refining is similarly discussed.The replacement of traditional technology by more attractive alternatives has occurred in a considerable number of operations. The develop-ment and status of new continuous smelting processes, advances in hydrometallurgy and refining innovations which emerged during the 1960s and early 1970s is discussed. The varying experience in commercial acceptance of these new technologies is noted.Finally some possible future directions are canvassed for both operators and the research and development institutions.

Jan 1, 1985

The conclusions reached by den Tex after a study of the fabric of some rocks from Broken Hill have been used to support the epigenetic hypothesis for the origin of the ore, first by Edwards (1959, p. 70) and then by Stillwell (1962, p. 131) in his criticism of Segnit's (1961) views. Den Tex claimed that the petrofabric study provided "independent evidence that the ore, at least in its present form, post-dates all events of a diastrophic nature in the area concerned".Repetition of this claim by Edwards and by Stillwell and the lack of any criticism of den Tex's work for more than three years implies its general acceptance by geologists in Australia. Therefore it appears necessary to examine parts of den Tex's paper in detail to show that his, conclusions are unwarranted. The major weaknesses in his study are that1. the petrofabric study was inadequate to warrant any major conclusions, and2. the petrofabric data allow alternative conclusions.Den Tex made a single visit to the field, collected six carefully selected specimens and presented quartz and· biotitepetrofabric diagrams for two specimens, quartz-diagrams alone for three more and included three diagrams of the orientation of c-axes and fractures in one specimen. It is not reasonable to come to firm conclusions about the origin of such a complex area as Broken Hill on such inadequate data, despite den Tex's claim (p. 87, lines 22 and 23) that "a thorough investigation of the quartz-fabric of the wall rock was undertaken".Den Tex's interpretation of each diagram is open to criticism, and alternative (and to my mind, preferable) interpretations may be made. It is impossible to evaluate den...

Jan 1, 1962

By Beavis FC, Box JC

The important chemical and fluid flow phenomena in heap, dump and in situ leaching are summarised. Published, quantitative models of these processes are critically reviewed, and their potential applications outlined. Comparison between the independent predictions of one of the models and column leach test data reported by others confirms the potential. Some recent developments by the authors in the fields of fluid flow through unbroken ore and modelling of the more complex chemical systems are briefly Described.

Jan 1, 1981

By Met M. E, Worner H. K

During the past two years, a large number of creep tests has been carried out on electrolytic lead, special assay lead and ordinary refined (Port Pirie) lead. Some of these tests have already been reported.1§ In addition, an attempt has been made to estimate the influence of the individual elements present in small traces in Port Pirie lead. The present paper gives the results obtained when small additions are made to "U" lead of the composition shown in Table 1.(which has been used throughout these investigations during the past few years). The additions were silver, antimony, bismuth and zinc. The results of the addition of tellurium have already been communicated. This investigation was intended to run parallel with a similar one using electrolytic lead as a basis and adding one element at a time.Actually, the experiments using "U" lead have got rather ahead of the others. The important point has emerged, however, that the effect of a .given addition may be appreciably influenced by the presence of traces of other elements.In most of these tests, an initial stress of 500lb. per sq. in. has been used. Whilst it is fully appreciated that this stress is higher than those used in practice, it has to be borne in mind that an improvement in creep resistance was *Manuscript received December 11th, 1936.

Jan 1, 1936

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 G S. Anderson, N W. McDonald

"The IsaMill™ was originally developed to address liberation issues at Mount Isa Mines (now Glencore) operations, McArthur River and Mount Isa in the early 1990s. Following on from the industrial success at those operations, the IsaMill™ was commercialised. In the year 2000, Kalgoorlie Consolidated Gold Mines (KCGM) became the first external user of the technology with a 1.1 MW M3000 IsaMill™ installed to supplement the roaster capacity at its Gidji Processing Plant. The IsaMill™ was used to ultra-fine grind about 10 t/h of pyrite flotation concentrate to 10–12 µm prior to gold cyanide leaching. Based on the success of the Gidji installation, another was installed at the processing plant at KCGM’s Fimiston operation in 2002 in a similar duty.In 2014, a 3 MW M10 000 IsaMill™ was selected to replace the roasters at Gidji as part of the A$98 M emissions reduction project. The mill was commissioned in April 2015 at the design 30 t/h, allowing the immediate shutdown of the two roasters. Replacement of roasting with ultra-fine grinding completely eliminated air emissions at Gidji while maintaining overall plant production rates.This paper details the history of the IsaMill™ at KCGM from the original M3000 to the latest M10 000. It covers the basis of the process selection, circuit design, operating and maintenance data.Citation:Anderson, G S and McDonald, N W, 2016. IsaMill™ at Kalgoorlie Consolidated Gold Mines - from the M3000 to the M10 000 and Replacement of the Roasters at Gidji Processing Plant, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 29–38 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By S Winter, G Klenowski

During longwall mining in the Bowen Basin, open tension cracks formed by overburden subsidence occur to a height of about 175 m above the mining horizon. Within this zone, water in aquifers or inundated workings will flow into the mine.At the Oaky Creek mines Aquila seam, open cut pits containing pit water overlie German Creek seam longwall panels at a height of about 105 m. The highly saline water is classified as contaminated and cannot be discharged off-site. Because alternative water storage facilities were not available, innovative water management solutions were needed to allow longwall mining to proceed without underground flooding.Computer modelling and underground inflow measurements have been completed to accurately determine inflow rates into longwall mines from overlying water sources at increasing overburden heights. Research work has also included determining cost-effective blanket treatment of final voids and reshaping spoil piles to minimise downward seepage.Ponded water overlying the Aquila low, Grasstree south and A6 pits required remedial works prior to longwall undermining to prevent flooding. In the Aquila low pit it was necessary to partition the pit and remove water overlying longwall 32. Two in-pit bridges were constructed by dozing and track compacting low wall spoil. The final void above the longwall panel was kept dry during undermining. Maximum recorded underground inflow rate was 30.0 L/s.The Grasstree south pit final void, part of the ramp and much of the spoil piles were inundated prior to undermining of 308 panel. A bridge and blanket were required to prevent ponding above the longwall. Maximum recorded inflow during undermining was 23.2 L/s.The pit A6 south final void, which contained dumped, saturated rejects and inundated highwall mining entries was undermined by longwall 36 at the Oaky No 1 underground mine. Because mapping of highwall entries was not available, the maximum calculated inflow rate of 73.0 L/s was based on all design entries being fully inundated. The actual inflow rate during longwall mining ranged up to 20.0 L/s.Water management improvements that have been implemented include greater use of contaminated pit water to wash coal, use of evaporation fans, and installation of a 6 ML/day reverse osmosis plant for water purification.CITATION:Klenowski, G and Winter, S, 2017. Inflows into longwall mines from inundated overlying workings, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 183–190 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017

By S Sims, A Stradl, G Hope, B Lacouture

Column flotation cells have been installed in numerous base metal operations around the world. The majority of these cells utilise conventional air-only spargers to introduce air into the bottom of the column. The recent development of instruments to measure the bubble characteristics in these columns has provided a renewed understanding of column behaviour. These new tools provided insight into why the columns at Red Dog Mine had never performed up to expectations. After efforts to optimise the spargers failed to substantially change the bubble size and air efficiency, alternate sparger systems were investigated. The Metso Minerals CISA Microcel sparger system appeared promising and was selected for a full-scale plant trial. The Microcel sparger system was originally developed for the coal industry at the Virginia Centre for Coal and Minerals Processing. In October 2003, a Microcel was retrofitted into one of two 3.66 m diameter flotation columns in the zinc retreat circuit at Red Dog Mine. The operation of the two different sparger systems in parallel allowed a detailed comparison. This paper discusses the performance of the Microcel based on the data collected during several detailed surveys. Bubble size measurements carried out in the pulp zone using the McGill University bubble viewer showed a significant difference in bubble size. The mean Sauter diameter of the bubbles decreased from 3.4 mm for the jetting-type sparger to 1.9 mm for the Microcel sparger. The overall recovery and the recovery by size fraction for both valuable and gangue minerals were compared. Paired t-tests demonstrated that the Microcel column produced a higher concentrate grade (0.6 per cent zinc absolute) and a higher unit recovery (2.8 per cent zinc absolute) than the existing Canadian Process Technologies Inc (CPT) SlamJet column. These improvements provided a payback period of 1.5 months for the $109 000 investment.

Jan 1, 2005