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By Whiten W. J

An investigation on the breakage characteristics of closely sized orc samples at different levels of input energy was carried out to determine an appearance function for possible use in ball mill modelling. A consistent pattern of breakage behaviour was observed and the resultant size distributions could be described by a one-parameter, ('t'), family of curves. For each particle size range tested, this parameter 't' has an exponential relationship with input energy below an upper energy limit. A tentative linear relationship between the input energy at a constant value of 't' and the work-index leads to reconstruction of 'I' - input-energy curves from the work-index values. To normalise the efrect of particle size and input energy, multidimensional cubic spline regression was performed on thc entire range of data. The results indicated that the parameter 't' can be determined, reasonably accurately, as a function of Ln (input energy, kWh/tonne) and Ln (particle size, mm) for input energies between 0.5 and 8.0 kWh/tonne.

Jan 1, 1983

Samples of a refractory copper ore were examined to test their response to segregation roasting, flotation, and acetonitrile leaching. Recoveries in the segregation roasting stage were between 60 and 100 per cent, while flotation recoveries varied between 60 and 85 per cent in cleaner concentrates assaying 25-40 per cent copper.The fraction of the copper which could be leached from the concentrate by an acetonitrile/sulphuric acid/cupric ion leach solution varied from 16 to 97 per cent, the lower recoveries being correlated with the presence of sulphide in the concentrate.

Jan 1, 1973

The beach sand industry is the only Australian mineral industry which, so far, has used electrostatic separation on a full commercial scale. The main application of the process is for the separation of rutile from zircon. Laboratory work has demonstrated that electrostatic methods are effective for ilmenite-monazite and cassiterite-zircon separations, thus facilitating the production of high grade monazite and cassiterite products from top-strip table concentrates, but the commercial application of these processeshas been rather limited so far. Overseas, electrostatic methods are becoming more widely used for the treatment of granular material which is not amenable to flotation. The use of electrostatic separation for the treatment of ores other than beach sands has been investigated in this laboratory 1, 2, 3, and two pilot separators were built during i953 to carry out field tests. Of these, the first was an inclined feed plate separator for the removal of silica from granular lime-sand in Western Australia, the second a conductance roll separator for the removal of diamonds from alluvial gravel in New South Wales. In both cases the whole of the ore passed through the separator, not a gravity concentrate only as in beach sand practice. The two types of separator mentioned are shown diagramatically in Figs. 1 and 2.

Jan 1, 1954

By M Watson, A V. Engelbrecht, E Murray-Hayden

Whereas mine reconciliation is a well-established month-end process for most modern mining operations, the resource sector has yet to endorse uniform reporting factors against which model accuracy and metal recovery can be formally assessed. Logically, any comprehensive reconciliation framework should facilitate comparison between period reserve, mine and mill and production figures. Historically, Parker’s F Series ratios (Parker, 2012) are often used in some form by mine operators, although they are rarely shared externally, as formal definitions have yet to be accepted. This paper presents a structural extension to the reconciliation process, wherein resource ratios (R Series factors) are used to quantify the long-term impact of the information effect, together with dilution and ore loss. A case study from the El Limón Guajes (ELG) Mine Complex in Mexico is used to demonstrate how an R Factor Series can be implemented to facilitate operation optimisation, over and above conventional F Series reconciliation treatments. This approach is applicable to any mining operation.

Mar 22, 2022

This paper describes a mobile laboratory developed specifically for nickel prospecting, and which was designed to be operated by sub-professional staff in remote areas independently of established laboratories. An atomic absorption spectrophotometric procedure was used to determine nickel, cobalt, lead, zinc, and copper ID latentIc and sulphIde samples, with a detection limit better than 25 µg/g for all elements. The procedure was applicable to both soil and drill samples and the accuracy of the procedure, which was ±5 per cent relative at the 1,000 µg/g level was sufficient for the preliminary assessment of mineralized samples and the control of drilling operations. The analytical procedure and the means taken to ensure the necessary reproductibility and accuracy are described. One operator can carry out 400 elemental determinations per 8-hr day at an approximate cdst of 6 cents per elemental determination. The results are returned within a single day, a factor which can contribute materially to the efficiency of drilling operations.

Jan 1, 1970

Additional Attractive Force Between Alumina Particles Due to Low Solubility of Dicarboxylic Acids

Sep 13, 2010

By Koch D. F A

An electrochemical study of the dissolution of gold in aerated cyanide solution shows that the dissolution rate is determined by the nature of the surface. A passive film (probably a basic cyanide) formed at -0·6 V vs a saturated calomel electrode inhibits both the anodic dissolution of gold and the cathodic reduction of oxygen. Thallium has an "activating" effect on these reaction mechanisms.INTRODUCTIONIn general the dissolution rate of a solid in a liquid is studied by weight loss measurements or analysis of the solution at known time intervals. However, if the solid is a metallic conductor, on which a redox reaction can occur at the metal-solution interface, it can be studied by electrochemical techniques. Electrochemical measurements have the advantage that the overall reaction can be separated into its components, in some cases by electrical measurements alone, and in others by a combination of these with analytical determinations.The overall equation for the dissolution of gold in aerated cyanide solution may be written4Au + 02+ 8CN- + 2H20 = 4Au (CN)2- + 40H- ..... (1)which can be separated into the two electrochemical componentsrepresenting the oxidation of gold and the reductionof ogygen respectively.4Au + 8CN-,= 4Au(CN)2- + 4eand O2+ 2H20 + 4e = 40H- These two reactions occur at the gold-electrolyte interface and it is the purpose of this paper to discuss the mechanism...

Jan 1, 1964

By Edmonds W, Jeffcoat R

The completion of the first two open hearth furnaces in the new No. 2 open hearth plant at Port Kembla will increase Australian production of steel by 350,000 tons of ingots per annum.The paper gives an outline of the essential features of open hearth design and auxiliary equipment required to operate the two modern open hearth furnaces at present being installed.INTRODUCTIONThe increasing demand for steel required by Australian secondary industries led to the decision to construct and operate No. 2 open hearth plant at Port Kembla. Two basic open hearth furnaces of the most modern design are under construction and it is anticipated that these units will be commissi.oned in September 1956. Australian steel capacity will thereby be increased by approximately 350,000 tons of ingots per annum.PLANT LAY-OUT AND CONSTRUCTIONIn the design and lay-out of this plant the emphasis has been on efficient material handling with simplicity of design and operation. Overseas methods were studied and these studies, together with experience gained at Newcastle and Port Kembla open hearth shops, enabled this plant to be built to a standard which compares favourably with any other in the industry.Initially two furnaces, each of 2,75 tons capacity, have been built, but provision has been made in. the design and lay-out to enable expansion to six furnaces.The location of the new plant in relation to the existing units will be noted in Fig. 5. It is one of the first units to be built in an area which will dovetail into a pattern for...

Jan 1, 1957

By Healy T. W, Dixon D. R

The present study 'of pure ZnS and NiS and ZnS (marmatite) by detailed electrokinetic methods has shown that by careful control of experimental parameters much new' information on sulphide-water interfaces can be obtained. Time-dependent processes of alteration of sulphide surfaces are foHowed by electrokinetic methods and indicate that the isoelectric point of the surface depends on elemental sulphur coverage, oxidation product coverage, and the conditions which promote or minimize such reaotions in the presence and absence of activator.

Jan 1, 1977

Delivered at the University of Sydney, on June 4th, 1954.THE TORCH WE HOLDLast year Our Institute celebrated its Diamond Jubilee, coincident with the holding of the Fifth Empire Mining and Metallurigcal Congress in Australia and New Zealand. We can be proud of our growth over the 61 years since the inaugural meeting in Adelaide in April, 1893, which followed suggestions from a provisional committee of mining men, formed in 1892 in Broken Hill.We can also be proud of our technical achievements in the fields of economic geology, mining and metallurgy.Should we be content with the growth of our mining and metallurgical industries over these years? My answer is in the negative. The discovery of new mineral deposits is essential for the continuance and development of the industries we represent.Let me review the background and trends of our industry in an attempt to emphasise the changing factors influencing the search for minerals and their exploitation.Australia was blessed with the discovery of coal in New South Wales in 1796; copper in South Australia at Kapunda, Burra, Wallaroo and Moonta in the eighteen-forties; gold in Victoria and Eastern Australia in the 'fifties; tin at Mount Bischoff, Tasmania, and gold at Charters Towers, Queensland, in the 'seventies; lead-silver at Broken Hill, New South Wales; gold and copper at Mount Morgan, Queensland, and copper at Mount Lyell, Tasmania, in the 'eighties; and gold at Kalgoorlie, Western Australia, and zinc-lead atRosebery, Tasmania, in the 'nineties. As well, the iron ore deposits of the Middleback Ranges, South Australia, and Yampi Sound, Western Australia, were known before...

Jan 1, 1954

By A Valero, G M. Mudd

There is active debate and research around the most suitable indicators to assess the sustainability of mining. The most common approach is to report a range of data for a given mine site (or less preferably, a company total), such as inputs, outputs, benefits and potential costs. The most popular protocol in use (and growing rapidly) is the Global Reporting Initiative (GRI). However, these measures are numerous and still do not allow a single over-arching indicator to be developed. Other measures, such as known mineral resources over time, do not account for critical challenges such as declining ore grades, increasing wastes and poorer quality ores or more difficult mineralogy. By adopting a thermodynamic approach to sustainability, through the concept of æexergyÆ, it is possible to incorporate into a single measure the effective quality of mineral resources. Exergy involves the assessment of the minimum energy costs involved in producing a mineral resource with a specific chemical composition and concentration from common materials in the environment. The exergy of a mineral resource is evaluated from mineralogic composition, concentration (or ore grade) and, of course, quantity, by multiplying the unit exergies with the tonnes of the resource produced (or consumed). Since exergy is a thermodynamic quantity (ie energy or joules), it is additive across different minerals, such as iron ore to gold to copper or even oil and gas or coal û making it an ideal indicator to assess mineral resource sustainability at the industry scale rather than the individual mine scale. This paper briefly outlines the theoretical basis for exergy, and then presents a range of commodity case studies showing the application of exergy to the Australian mining industry. Overall, the usefulness of exergy is clearly demonstrated for use as a broad indicator of the sustainability of mineral resources at the national or even global scale.

Jan 1, 2009

By J Elsen, R Snellings, K Van Balen

This research concerns the mineralogical study of the physico-chemical reactions taking place at the pozzolan-binder interface. Lime binder/ pozzolan mixtures have been prepared for different natural zeolites. Analcime, phillipsite, chabazite, erionite, mordenite and clinoptilolite were mixed with portlandite and water, after which the progress in the reaction was quantitatively determined by thermogravimetrical analyses from three to 180 days. A first and important step was the thorough characterisation of the raw materials by quantitative X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscope energy- dispersive X-ray (SEM-EDX) measurements of the zeolite minerals, Brunauer-Emmet-Teller (BET) specific surface area measurements, grain-size analyses and cation exchange capacity measurements. Beside these zeolite samples with varying Si/Al ratios, two clinoptilolite samples exchanged to the calcium, potassium and sodium form were studied and the difference in their short- and long-term reactivity was assessed. Also the difference in reactivity between identical clinoptilolite samples ground to different grain sizes, obviously having different specific surface areas, was determined experimentally. The results indicate that the external surface area only influences the short-term reactivity, whereas the cation content has effect on both long- and short-term. Na-exchanged samples combine clearly more portlandite in the first few days, whereas the reaction slows down afterwards compared to K- and Ca-exchanged samples. The early reactivity of the unexchanged zeolite samples could be explained by these two parameters, but their long-term reactivity seemed to be related to their Si/Al ratio. Samples with zeolites rich in Si reacted faster then their Al-rich counterparts.

Jan 1, 2008

By S Hapugoda, J R. Manuel, M J. Peterson

Microindentation testing using the square–pyramid–shaped Vickers indenter is a well-established technique to determine the microhardness of minerals and materials. However there is a paucity of published microhardness data from Fe ore samples. It is acknowledged that an iron ore’s particle mineralogy and texture is critical to its processing properties, and it is therefore considered that the microhardness of different mineralogical/textural types may also relate to these properties. Mineral microhardness potentially provides inputs to the modelling of breakage characteristics during comminution, as well as the relationship between mineral chemistry and microhardness, and mineral microporosity and microhardness. Microhardness can be determined as single crystal microhardness, for more coarsely microcrystalline samples, or as ‘aggregate microhardness’ for cryptocrystalline or finely microcrystalline samples.Variations in the texture and mineral chemistry of common Fe ore minerals (eg martite and microplaty hematite, ochreous and vitreous goethite etc) are well established and this study provides microhardness data on different textural forms of Fe (oxyhydr)oxides from a variety of different Fe ore deposits. The data indicated that in general, the mineral grain size, microporosity and texture were the main influences on Fe (oxyhydr)oxide microhardness. There were no apparent systematic variations between microhardness and minor element mineral chemistry, with the possible exception of Al content in goethite (for goethites with Al content >0.5 wt per cent), and for goethite total element contents >90 wt per cent (determined by electron probe microanalysis, EPMA). Higher Al concentrations and lower total element concentrations in goethite EPMA analyses correlated with lower goethite microhardness. Microporosity and grain size were more important than texture to hematite microhardness. Different textural forms of dense hematite (eg martite, recrystallised interlocking hematite and specular hematite) with similar grain size exhibited comparable microhardness. Microhardness values for hematite and hydrohematite with little or no evident microporosity were also similar, whereas more porous forms of martite, microplaty hematite or hydrohematite exhibited lower microhardness.CITATION:Peterson, M J, Manuel, J R and Hapugoda, S, 2017. Microhardness testing of hematite-goethite Fe ores – implications for their textural characterisation and geometallurgy, in Proceedings Iron Ore 2017, pp 319–330 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By O Haavisto, N Khajehzadeh, L Koresaar

Online analysis of metal content can be used to optimise the grade and recovery of a flotation circuit. Compared to conventional laboratory analyses, the benefit of an online analyser is the speed of the measurement, therefore disturbances (eg changes in feed grade and decrease in recovery) can be reacted to in real time by an operator or automatic process control system. In some cases traditional X-ray fluorescence analysers can be applied to silica analysis in iron ore when the SiO2 grades are high enough and have a negative correlation with iron; however, generally a laser-induced breakdown spectroscopy (LIBS) analyser is more suitable for low Z elements.The Outotec Courier 8® analyser is a LIBS based analyser able to measure elements starting from lithium (Z = 3), thus being able to measure impurities; eg silica and aluminium directly in iron ore slurries. Besides online elemental analysis, the analyser can be combined with optical measurements for rapid continuous measurement of each sample line. Laboratory testing has also shown potential for mineralogical analysis using the combination of LIBS and reflectance spectroscopy.CITATION:Koresaar, L, Khajehzadeh, N, Haavisto, O and Timperi, J, 2017. Online elemental and mineral measurement of slurries in iron ore beneficiation, in Proceedings Iron Ore 2017, pp 561–566 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

The objectives of this paper are to introduce the International Code of Practice for Risk Management of Tunnel Works and to illustrate to the participants of the 13th Australian Tunnelling Conference 2008 how the insurance industry would like to see the future of tunnelling insurance. Tunnel construction projects have suffered large losses over the years as can be shown from various loss examples and a list of major losses over the last ten to 15 years. Since the consequences of insufficient risk control had to be borne by insurers, these losses have heightened the need for improved and adequate risk management measures so that insurance cover can also in future be provided for this hazardous industry sector. Observations are made as regards to the prevailing trends in the tunnelling industry, which contribute to the increase in risk and have adverse consequences for the insurance industry. To find a solution to this dilemma various options are examined with the suggestion of a Joint Code of Practice for Tunnel Works being agreed by all stakeholders, which would become essential to secure future insurance protection for such project work. The British Tunnelling Society has, in cooperation with the Association of British Insurers, developed such a code, which the International Tunnelling Insurance Group has now adopted for global application in international markets. The content and concept of this code is explained to establish a framework of understanding and applied risk management principles for tunnel works. This initiative also has the support of the International Tunnelling Association and the International Association of Engineering Insurers. The international application of this new code is demonstrated with a few examples, which also includes Australian projects. It is the aim that this code forms in future part of the insurance coverage for tunnelling works in order to put this risk segment on a more sustainable basis. For that reason the insurance industry is seeking the support of all stakeholders of tunnelling construction projects.

Jan 1, 2008

By Firth B. A

The classification performance of a Dutch State Mines (DSM) Rapped Sieve Bend has been investigated in a series of experiments. Coal slurries of a nominal 0.5 mm size were classified in the separation range of 0.10 to 0.14 mm at pulp densities from 6 to 21 per cent by mass of solids, and flow rates of 110 to 1375 litre min-1.The results obtained showed that the partition curve and water split io oversize was dependent on the solids flow rather than slurry flow rate or pulp density. For most of the operating conditions considered an accurate classification of the fine coal was obtained. The undersize efficiency was susceptible to solids flow rate, and was less than 70 per cent for solids flow rates greater than 16.7 tonne hour-1 metre-1 width of screen.

Jan 1, 1983

Traditionally, capital costs of major resource development projects have been estimated as a single amount to which a percentage accuracy has been assigned based on the method of preparation of the estimate, that is, on the amount of information available to develop the estimate.However, there is a growing recognition of the importance of a probabilistic approach to capital cost estimates, and of a more rigorous calculation of estimate accuracies and of the presentation thereof. Accuracies can be expressed with more certainty as a percentage of the estimate amount where the percentage represents one standard distribution on the probability curve for the capital cost of that specific project. Thus confidence levels can be stated for various estimated amounts - for example, it can be stated that there is an 85% chance that a stated amount will not be exceeded, or a 90% certainty that a (higher) amount will not be exceeded. Moreover, the right skewness of the probability distribution curve for most projects can be readily recognised and reflected in the evaluations. This enables senior executives and board members to have a clearer understanding of investment uncertainties, and the possible magnitude of commitments.

Jan 1, 1990

Geochemical data on Australian granites and pegmatites, and the mineral components of these rocks, are compared with that obtained in similar studies in the U.S.S.R. and elsewhere.The geochemical character of tin granites and the trace chemistry of their component minerals, particularly biotites, have some significance as ore guides in prospecting for tin.The primary geochemical dispersion of tin can be readily tested both in the laboratory and field by colourimetric methods, after volatilization with ammonium iodide, using modifications of the method described by Wood (1958).Secondary dispersions of tin in residual soils or alluvia can likewise be readly tested by rapid colourimetric methods in the field, but simple hydraulic methods, handling larger sample volumes, give reliable outlines of dispersion patterns.INTRODUCTIONThe search for tin ores, whether lode or placer in type, is usually directed on genetic grounds to country within or adjoining acid intrusives.A long established means of prospecting is to test samples for cassiterite by panning or other hydraulic separation.These methods can be used on crushed lode material or the natural materials from placers.With the advent of new techniques for extraction and for colourimetric analysis for tin (Wood, 1958 and Ross and White, 1961) a means is available for rapid analysis of materials not susceptible to quantitative testing by hydraulic methods because of the fine sizings of cassiterite or the occurrence of tin structurally held in minerals. The new methods thus opened up the field of tin prospecting by extending the search for ore guides to genetically associated rocks and minerals, wall ror-ks of veins and a wider range of superficial deposits.

Jan 1, 1963

By R L. Brathwaite

Previous paleodepth studies of low-sulphidation epithermal Au-Ag deposits in the Coromandel region indicated that economic gold mineralisation was generally limited to a depth zone of 100 to 400 m below the paleosurface. Notable exceptions are Waihi and Karangahake, where ore shoots extended to depths of about 750 and 900 m respectively. These studies have been extended to include Au-Ag, Hg and Sb epithermal deposits in Northland and the Taupo Volcanic Zone. The main paleodepth indicators used are sinters and hydrothermal eruption breccias, hydrostatic pressures estimated from homogenisation temperature measurements on fluid inclusions, and hydrothermal alteration mineralogy. Also the occurrence of lacustrine and fluvial sediments is an indicator of the paleosurface at their time of deposition. Selected paleodepth indicators have been compiled and mapped in a GIS environment. The distribution of the paleodepth indicators are used to define regional variations in erosion levels, and may be useful in predicting areas most likely to preserve the optimum depth window for gold deposition. In the Coromandel region, regional stream sediment geochemical data has also been used to broadly define erosion levels in terms of Zn, Pb and Cu representing deeper base metal zone mineralization and Hg and Sb representing shallower cinnabar and stibnite mineralisation. The interpretations of paleodepth and potential reconstruction of paleosurfaces are limited by the paucity of data, poor age control on the paleodepth indicators and the epithermal deposits, and marked relief and complex stratigraphy in the volcanic terranes.

Jan 1, 2003

Suggestions have been made at various times that there may be a recurrence of lodes similar to those at Kalgoorlie in the country to the south of the Golden Mile, but, so far as is known, there has been no geological evidence to support these suggestions apart from the possible extension of the younger quartz-dolerite greenstone in this direction.Geological mapping carried out by the writer in the Coolgardie district in 1946, provided some additional geological evidence to support this claim, and the ideas then held have since been expanded and are now considered to be sufficiently advanced to present them as concrete suggestions. As will be seen from the following pages, the critical area for lode prospecting is Hannan's Lake, where the basement rocks may include younger quartz dolerite greenstone, which, although perhaps distributed over a smaller area than at Kalgoorlie, could, on structural grounds, have a similar fracture system and similar ore deposition.There is little need to stress the importance discoveries in this area would have in prolonging the life of the field, and stimulating the post-war gold mining revival.Previous Work: Only the publications having a direct bearing on the preparation of this paper are given in the list of selected references, but the writer is very conscious of the fact that much other geological work has been carried out in the Kalgoorlie district since its discovery, by the W.A. Department of Mines, by mining companies, and others, all of which has contributed to the present knowledge of the field, and acknowledgment of the value of this work is given herewith. In presenting the suggestions in this paper a broad structural control of ore deposition is assumed, but this has already been established in other parts of the goldfields of Western Australia, including adjacent areas. In the early nineteen thirties, the Western Mining Corporation commenced work on the basis that there was a close relationship between geological structure and auriferous ore deposition, and a similar approach was first made by the Geological Survey of Western Australia in the South Yilgarn in 1935. These ideas were further developed during later surveys, particularly in the North Yilgarn and the Mount Margaret Goldfield.During the Coolgardie Survey in 1946, broad structural mapping was done in greater detail than before, and the structural ideas were implemented and further developed, leading to some success.Other work to which particular acknowledgment is given is that of Stiltwell, Gustafson and Miller, Forman, Prider and Finucane, at Kalgoorlie, and that of Honman in the Kalgoorlie-Coolgardie district, references to which are given at the end of this paper.Valuable constructive criticism of this paper has been given by Professor E. de C. Clarke and Dr. R. T. Prider, of the University of Western Australia.

Jan 1, 1950