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By Brien RT, O&apos

The work reported in this paper extends,-bhsb on the "Heat Hardening of Artificial Magnetite ;Pellets"., which was described at the- International Symposium on Agglomeration ;-sponsored by the American Institute. of Mining, Metallurgical and Petroleum Engineers at Philadelphia; U.S.A. in April, 1961. Whereas- that work was of a.,more basic nature, -serving to illustrate the suitability of artificialòmagnetites with various.admixtures, to the application of heat hardened pellets, on: this occasion the aim-is to illustrate the procedures-which were used-to- establish the dimensions of commercialòrecuperativ strands for Australian raw materials,The nature of the pellet feed, i.e. relatively uniform :spheres of4 3/8 in. - 7/16. in. diameter, makes it possible to use small scale static pots for test work. By the use of a closed system and the measurement of suctions, gas f lows, and temperatures through beds, the speed and heat requirements of the various stages of heat hardening can be measured, so: that for a specified quality of product estimates can be made of the broad design characteristics of a moving grate system. In practice of course it is .usual to correlate the data from this type-of :experimental 'apparatus with . existing production units upon which good operating data, in the statistical sense, are available.

Jan 1, 1963

By I Basson, J A. Miller, M Becker, F C. de Beer, L C. Bam

"Geometallurgy brings together geologists, mine planners and process engineers to extract meaningful mineralogical and textural information from an orebody, with a view to predicting its metallurgical response. Preferably, automated analytical techniques, which provide mineralogical and textural information, should process a large number of samples quickly, relatively inexpensively and reliably. Microfocus X-ray computed tomography (µXCT) is capable of producing 3D volumetric information on texture and mineralogy that satisfies some of these criteria. µXCT has been used extensively to study the porosity and internal pore structure of iron ore pellets as part of downstream processing. It has not been widely applied to earlier mineralogical and textural analysis of unprocessed ore, due to the limited ability of X-rays to penetrate high-density samples. In this contribution, we propose scanning methods to overcome this limitation, thereby facilitating a broader application of µXCT to iron ore resource management.CITATION:Bam, L C, Miller, J A, Becker, M, De Beer, F C and Basson, I, 2016. X-ray Computed Tomography – Determination of Rapid Scanning Parameters for Geometallurgical Analysis of Iron Ore, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 209–220 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By D B, M A. Sares, D W. Coulter, D C. Peters

This presentation discusses NASA-funded research on the ability of hyperspectral remote sensing to map diagnostic acid rock drainage (ARD) mineralogy that adversely affects water quality within watershed and to determine the relative contributions of natural ARD sources of metals and acidity to that drainage. Ground-based reflectance spectroscopy, combined with water chemistry, is used to identify mineralogical and chemical variations throughout a watershed. Integrated with hyperspectral data acquired from airborne remote sensing platforms, such as the NASA Airborne Visible Infrared Imaging Spectrometer (AVIRIS) sensor, a methodology has been developed that should improve environmental assessments and tracking of impacts on and from drainages. Phase I of this project focuses on a drainage basin (Lake Creek), tributary to the upper Arkansas River in central Colorado, which is impacted by natural acid rock drainage from areas of high-sulfide hydrothermal alteration. This project builds upon research and inventory efforts by the Colorado Geological Survey (CGS) to identify hydrothermal alteration that is the primary source or is contributing to acidic and toxic drainage in Colorado. This presentation will cover ground and airborne hyperspectral remote sensing techniques and results and water analyses for seasonal high-flow and low-flow conditions in Lake Creek. Identifying correlations between mineralogy, especially mineralogy that can be identified through airborne remote sensing, and water chemistry is a key focus of this project. Of particular interest are low-pH iron phases such as jarosite, ferrihydrite, schwertmannite, copiapite, and transitional amorphous phases as well as AlOH phases from higher, although still acidic, pH environments which are observed to mix with the iron precipitates within the streams draining from the hydrothermal systems. Drainage in the Lake Creek watershed derives from the Grizzly Peak caldera (Oligocene), which exhibits extensive hydrothermal alteration. Alteration types include silicic, quartz-sericite, quartz-sericite-pyrite, advanced argillic, and argillic. By understanding the chemistry of a naturally impacted drainage and its relationship to the surrounding geology, the project goal is to allow more efficient and complete identification of such sources in mineralised terranes through remote sensing technology.

Jan 1, 2003

Giving the keynote address in the final session of a conference dealing with closely related topics has a disadvantage in that much of what can be said has been said. It also has an advantage, however, because it presents the speaker with the opportunity to integrate and analyse the material presented by the various speakers. I would like to look to the near future in Aust- ralia and the United States of America, to the risks, problem areas, and changes of a rapidly evolving post-industrial era-an era we are begin- ning to experience where industry no longer `calls the tune'. We miners have been quick to point out and emphasize, that ours is a `high-risk' industry in the world of business and commerce. Yet, clearly those who have survived, and been successful, have learned to anticipate and cope with risk and change. This ability has been a distinguishing feature of the industry's leaders who, in market studies and commodity selection, exploration and development, mine planning, metallurgical pro- cessing, and general administration and operation 1. identify areas of risk or inevitable change, 2. analyse, test and quantify those factors of risk or change, and 3. design methods, systems, equipment to elim- inate, moderate, or control or economically compensate for predicted risks or changes.

Jan 1, 1978

Although I have, for most of my working life, been associated with research into problems of water pollution, this has been exclusively in a country where problems arise from having too many people rather than too little water, a country furthermore, where for the past few decades, mining, except for coal, could hardly be called a major Industry.

Jan 1, 1971

The GDR has extensive lignite deposits at its disposal, which formed the basis for the development of an independent energy source after 1945 and which will retain their significance well beyond the year 2000 (see fig. 1). In 1946 lignite output was about 110 x 106 t. In 1985 312x 106 t was produced and in 1988 the planned output will be ca. 315 x 106 t. Thus, the domestic produc- tion of lignite covers ca. 75% of the GDR's primary energy requirements. More than 80% of the electrical energy is gener- ated by the use of lignite and about 12% by nuclear energy. In addition to this, about 18 x 106 t/a mineral oil and about 6 x 109, m3/a natural gas are imported, predominantly from the Soviet Union. The lignite deposits of the GDR are of Tertiary origin and are recovered exclusively by opencast mining. There are two large regions (fig. 2): - in the region east of the river Elbe (Cottbus/Senftenberg- "Niederlausitz") and - in the region west of the river Elbe (Halle/Leip- zig/Magdeburg). These deposits differ in geological age and conditions of depo- sition, consequently there are differences in their chemical and physical composition and, thus, in their uses. The younger Mio- cene coals of the main region in the East of the river Elbe belong to the epirogenetic type and have a low content of ash and sul- phur. Among other things, they are suitable for the production of brown coal high-temperature coke (Lauchhammer and Schwarze Pumpe). The older Oligocene coals of the Halle/Leip- zig region are bitumenous in certain areas. Therefore, they form the basis for production in low-temperature carbonizing and chemical plants. In the Halle-Magdeburg region, where the lig- nite is in contact with the underlying Zechstein subdivision, so- called "salt coals" are found.

Jan 1, 1989

By C V. Putnis, T Geisler, A Putnis

In nature, ilmenite (FeTiO3) undergoes weathering through oxidation and removal of Fe to form an apparently continuous series of compositions from ilmenite to pseudorutile (ideally Fe2Ti3O9), and with further weathering, to leucoxene. To determine the mechanism of acid-leaching of ilmenite to ultimately form rutile, we have carried out an experimental study of ilmenite alteration in autoclaves at 150¦C in HCl solutions. Resulting products were studied by X-ray diffraction, scanning electron microscopy, electron microprobe and Raman spectroscopy. In some experiments the solution was initially enriched in 18O and the distribution of the isotope in the alteration products mapped from the peak shift in the Raman spectra. The results indicate that the alteration may proceed in two stages, each with a sharp interface between the parent phase and the product. The alteration begins at the original ilmenite crystal surface and along cracks through which the fluid can migrate. The first alteration product is pseudorutile û no phases intermediate between ilmenite and pseudorutile were detected. The textural relationship between ilmenite and pseudorutile suggests a coupled dissolution-reprecipitation mechanism rather than a solid state continuous oxidation and Fe diffusion mechanism. The second stage involves a further dissolution-reprecipitation step to form rutile. Raman spectroscopy shows that the 18O is incorporated in the rutile during the recrystallisation. Throughout the alteration process the original morphology of the ilmenite is preserved although the product is highly porous. The rutile inherits crystallographic information from the parent ilmenite, resulting in a triply-twinned rutile microstructure.

Jan 1, 2008

Vatukoula is a gold mining township situated at the south-west periphery of a Tertiary caldera which measures 3 miles by 4 miles. Erosion of the caldera resulted in the formation of a topographic depression, called the Tavua basin, covering about 30 square miles. This area, also known as the Tavua Goldfield, has been the site for spasmodic prospecting since the initial discovery of gold in 1932.The mineralization at Vatukoula is typically epithermal with the gold occurring as tellurides, auriferous sulphides, and to a much less extent as native gold. The lodes are confined to three major structures i.e. north-west shears, flatly dipping structures (flat makes), and local shatter orebodies.Within these structures, at least five types of controls are recognized to account for the localization of the oreshoots. The dominant control is structure.The lode structures are related to the overall structural pattern of the Tavua basin. This pattern, which is controlled by the collapse planes of the caldera and a north-west shear system, produced a "shatter block" atVatukoula and elsewhere around the caldera.Structural analysis indicates there are certain areas in the Tavua basin where exploration could be rewarded by the discovery of orebodies with similar controls to those of the productive Vatukoula block.

Jan 1, 1967

By D Price

Mining at the Tuckabianna Mining Centre in the Murchison district of Western Australia ceased in 1997, after the production of 550 000 ounces of gold at an average grade of 2.5 g/t from 22 separate open pits (Tectonic Resources, 2006). Like many historic mining camps in WA, Tuckabianna was considered exhausted of gold, such that an economic project could not be sustained on the existing resources. Since 1997, three separate companies have owned the Tuckabianna leases. Each of these companies completed minor exploration and some form of mining study to determine if mining could be sustained. All three companies concluded that the remaining resources were insufficient to support an economic project. Silver Lake Resources acquired the adjacent Tuckabianna, Comet and Moyagee projects in 2007 with a combined resource base of 693 000 ounces of gold in 11 separate deposits. In September 2009, Silver Lake commenced exploration in the Murchison targeting extensions to the main resources at the three project centres and completing targeted regional exploration across the lease holding. At the same time, a detailed evaluation of all historic drill data was completed and all resources re-estimated. This has culminated in the resource base increasing to 1.5 million ounces of gold in 20 separate deposits, with two new discoveries being made. In August 2010, a mining feasibility study was commissioned. Preliminary results from the study indicate that an economic stand alone project can be sustained for a minimum of five years. The ability to bring the remaining resource from a once unloved project into production is due to a number of factors: historically high gold price, combining adjacent projects into a single operation, evaluation of all resources regardless of size and grade, and well funded exploration directed to both resource extensions and new discoveries. Using the Tuckabianna Project as an example, this paper attempts to outline the strategy Silver Lake used to define the resources to justify the capital expenditure required for production, and give a summary of some of the successes and failures made as the projects progress towards mining. Examples of where being too rigid and over exuberant have resulted in less than optimal use of expenditure are used to high-light the difficulties in exploring in mature terrains. Evaluation of the success of a company’s exploration strategy at all scales from project acquisition to target selection is critical to the success of future project development. This paper has been part of that process for Silver Lake with some interesting discussions and insights being made. It is hoped that some of the points discussed can be applied to other projects to help achieve the best outcome from the assets available to a company.

Aug 22, 2011

The investigation of Noapara glass sand deposit in Sylhet district of Bangladesh is performed to beneficiate the sand for the manufacture of colourless glass. For the ease and efficient removal of the colour bearing impurities, the physical and mineralogical investigations of the sand deposits is carried out first. The sand is then treated with the standard beneficiation procedures to reduce the impurity level to an acceptable level. It is found that the Noapara glass sands are of medium grained and moderately sorted. They contain 0.15 - 0.30 per cent Fe2O3 and 0.001 -0.008 per cent Cr2O3 as major colour bearing impurities. The heavy mineral fractions containing most of the impurities can be grouped into five types of associations:stable or ubiquitous minerals (tourmaline, zircon, rutile); metamorphic species (staurolite, kyanite); amphibole minerals (hornblende, tremolite); the micas (muscovite, biotite); and discrete minerals (magnetite, ilmenite, etc). It is also seen that, the use of mechanical separation process in combination with water washing, attrition, and magnetic separation can remove a maximum of only 70 per cent of total Fe2O3 present in the deposits. This is insufficient to produce the specified grade of sand to manufacture colourless glass. Among the various chemical treatment processes used, sodium dithionite method is found to be the most effective, although the discrete minerals are not removed. Using the specific reagent group during froth flotation, the iron and chromium contents are reduced to 0.03 and 0.001 per cent respectively which are very near to the specified colourless glass composition.

Jan 1, 2000

By L Terrusi

The Bungaroo Valley hosts a concealed Tertiary channel iron deposit (CID) along a 17 km stretch of its length. Bungaroo Valley is approximately 0.5 km wide upstream at its easternmost extent, and 3.5 km wide downstream where it joins the Jimmawarrada Creek. The valley follows the axial trace of an anticline that plunges gently to the southeast, and the CID infills the valley. Mineralisation extends to a depth of 230 m below the surface, and almost the entire deposit occurs below the water table. Bungaroo Valley cuts through the Buckland Hills and is bounded to the north and south by steep scarps capped with the resistant Dales Gorge Member of the Brockman Iron Formation. Basement rocks are believed to be mostly Wittenoom Formation shales and dolomites, with Mount McRae Shale and Mount Sylvia Formation also present. Deep, localised depressions appear at the base of the CID sequence towards the north edge of the upstream section of the valley, while downstream the basal CID contact is relatively flat and shallow. In both cases the profile of the CID surface closely mirrors that of the basal contact. The localised depressions seen in the upstream basal CID contact produce significant variations in CID thickness of up to 100 m over short strike distances. This uneven palaeotopography is most likely due to eddying and waterfalls forming within the riverbed prior to CID deposition during a time when the water table was much lower than at present. It may also be associated with possible karsting in an underlying dolomite unit and subsequent syn- or post-depositional collapse of the overlying CID. The irregular basal contact of the Bungaroo CID sequence has implications for mining in terms of pit design and resource accessibility.

Jan 1, 2007

By A Mehrani, F Zamani, A Dehghani

Vibrating screens play an important role in the dry classification circuit of Gol-e-Gohar iron ore processing plant. This circuit was designed to classify the autogenous mill discharge and produce a suitable feed, with K80 about 450 ¦m, for dry magnetic separators. Three parallel vibrating screens produce more than 50 per cent of the separatorÆs feed. The efficiency of the magnetic separator is greatly affected by feed size distribution. In this work, the JKSimMet 5.1 software was used as an analysing tool to assess the flow rates and USIM PAC3 software as the simulation tool to control and optimise the vibrating screens. Samples were collected and the circuit was mass balanced. Then the vibrating screen was simulated and adjustment parameters such as cut-point, bypass and imperfection factor were determined. The product streams of vibrating screens can also be predicted.

Jan 1, 2007

Chlorine as a lixiviant for gold possesses a number of significant chemical and Idnetic advantages over cyanide but because of its corrosive and vaporous nature the method of implementation needs to be significantly modified. At comparable reagent concentrations the dissolution rate for gold in the C12/Cl- systems is some 10 - 100 times that achieved in the 02/CN system. The dissolution rate in the chlorine system is largely a function of the concentration of C12, Cl- and pH. Under conditions of low Cl', (less than 50 g/1), the dissolution rate begins to drop off dramatically over the pH range from 3 - 4. Increasing the level of dissolved chloride ions shifts the pH of this rate reduction to around pH 5 at 100 g/l NaCl, and to around pH 6 at 300 g/l NaCl.

Jan 1, 1991

By Propster M, Choudhry M

THIS note gives comments on the paper by Kitaev et al on p. 68 of this book and compares results with those obtained by ourselves. We wish to say that the authors are to be congratulated on their sophisticated approach to an important problem and that it complements our efforts on flow maldistribution.1-5 It is our view that Eqs. (1)-(5) on p. 69 are impressive, but unfortunately with present day computers and computational facilities, it would be quite impractical to contemplate the numerical solution of these. Eq. (8) in the authors' paper, on p. 70, does provide the logical starting point for tackling flow maldistribution problems and strictly speaking this equation is more accurate than Eq. (1) in our paper in this book. We note in passing that there is direct experimental evidence to support the contention that our Eq. (1) is at least a reasonable approximation and one may question in a practical sense whether the refinement afforded by Eq. (8) in the paper by Kitaev et a/ is justified. While one must readily accept the appropriateness of Eq. (8) of Kitaev et al as a starting point, the subsequent mathematical manipulation by the authors is open to serious criticism. In order to solve this complex, non-linear equation Kitaev et al postulated irrotational flow, which afforded considerable simplification. One can argue simply on physical grounds that the assumption of irrotational flow is inappropriate, a fact which should be readily apparent on inspection of the flow fields shown in Figs. 2 and 3 of Kitaev's paper. It follows that while the starting point through the use of Eq. (8) is correct the results derived from this starting point may be suspect because of the erroneous nature of the irrotational flow assumption.

Jan 1, 1975

By Edmonds G. A

The power station went into operation in 1931, when the installed capacity was 12,500 kVA. with a loading of 4,000 kVA. In 1936 the loading increased to 6,750 kVA. which necessitated the addition of a third set which went into operation in 1937, the installed capacity at that date being 18,750 kvA. with a loading of 7,000 kVA. This remained fairly constant until 1945, when a gradual increase was noticed, the loading in 1952 being 10,598 kVA.With the addition of the copper plant, additional generating capacity was required and it was decided to raise the installed capacity by the addition of a fourth set to 34,375 kVA. with an expected loading, when producing copper, of 20,000 kViA.MAIN POWER PLANTThis consists of three GiE.e. alternators of 6,250 kVA. or 5,000 kW. at 0.8 P.F. rating and one G.E.C. alternator of 15,625 kVA. or 12,500 kW. at 0.8 P.F. rating, making a total generating capacity of 34,375 kVA.Each alternator is driven by Fraser and Chalmers turbines at 3,000 r.p.m.SYSTEMThe main 3 phase 3 wire 3,300 volt distribution system has the neutral point of alternators earthed through by one or two earthing resistors designed to limit earth fault current to 3,000 amp. for 20 seconds, in the case of the large machine, and to 1,100 amp. for 10 seconds, in the case of the smaller machines, or full load of either size machine at rated voltage.

Jan 1, 1953

Low-grade manganese ore from Sandur, India containing 28.2 per cent manganese and 20.9 per cent iron was roasted with sulphating agents, viz ammonium sulphate and sulphuric acid. The effects of temperature of roasting (300 - 800°C), time (15 - 120 minutes) and amount of sulphating agent (0.5 to 2.5 times stoichiometric amount) were studied. Under optimum conditions, it was possible to extract 92 per cent manganese with 0.5 per cent iron at a temperature of 700°C for 90 minutes duration with stoichiometric ammonium sulphate. Further increase in quantity of ammonium sulphate has marginal effect on manganese extraction.Similar studies were carried out with sulphuric acid, and an extraction of about 87 per cent manganese with similar iron contamination was achieved at a temperature of 700°C for 60 minutes duration with stoichiometric quantity of the reagent. Selective extraction of manganese with respect to iron is discussed.

Jan 1, 1996

By K Edwards, A J. J Mouton

Hematite represents the vast majority of iron ore exported from Australia as the development and processing cost of magnetite is generally seen as a barrier to the development of vast magnetite resources. However, a number of magnetite projects have attracted a significant amount of interest and investment from large Chinese steelmakers.This paper compares the relative merits of the development of Australian magnetite and hematite ore from the point of view of the steelmaker, taking into account the factors that influence the capital costs of the development of the ore types and the relative costs of operating the process plants to treat these ores. By modelling the relative operating cost for the production of hot rolled coil in China for the two ore categories, the paper demonstrates the economic drivers behind the Chinese steelmakers’ large investments in the magnetite resources of Western Australia. It does this by estimating the potential value of magnetite concentrate to the steelmaker in the event that the maximum potential is realised by operating the blast furnace with a 100 per cent pellet burden.Under the conditions described, it was found that direct reduction (DR)-grade magnetite concentrate could command a price premium over 62 per cent Fe fines of up to 46 per cent (December 2014 on a cost and freight (CFR) basis). The corresponding premium for blast furnace (BF)-grade magnetite concentrate is 17 per cent, which demonstrates the dependency on grade.The capital expenses for a 14 Mt/a concentrate plant is estimated at US$3.1 B for BF-grade magnetite and US$3.35 B for DR-grade, with operating expenses at US$45 and US$50 respectively. The corresponding free on board price for a break-even net present value is calculated at US$82/t for BF-grade magnetite and US$90/t for DR-grade. The minimum long-term iron ore price (62 per cent Fe) that would be required to underpin such a project is estimated at US$78/t CFR for BF-grade magnetite and US$68/t CFR for DR-grade concentrate.Apart from the financial benefits, it is demonstrated that the use of magnetite concentrate in ironmaking has the potential to reduce CO2 emissions by approximately 400 kg per tonne of hot rolled coil.CITATION:Mouton, A J J and Edwards, K, 2015. Magnetite – a higher-grade blast furnace feed and its potential benefits for the ironmaker, in Proceedings Iron Ore 2015, pp 613–620 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By M Kim, J Park, I-K Suh, E Kim, J Lee

One of the key technologies in developing hydrogen-enriched ironmaking operations is the control of the carburisation, melting, and dripping behaviour of the iron ore burden materials. When a hot compacted iron (HCI) is charged in the blast furnace or the FINEX Melter-Gasifier, iron oxide reduction, the reduced iron’s carburisation, and the melting of iron and slag occur successively. This study investigated the reduction, carburisation, melting and dripping behaviour of HCI under a COH2 gas mixture using the high-temperature X-ray radiographic technique. Under 100 per cent CO gas atmosphere, the dripping temperature was 1410°C. When 5 per cent H2 was introduced, the dripping temperature slightly decreased to 1400°C. Furthermore, the dripping temperature gradually increased as the H2 gas composition increased. As 30 per cent H2 was introduced, the dripping temperature reached 1414°C. The carbon concentration in the drained metal samples gradually increased with increasing H2 composition. It is considered that H2 decreased FeO content in the slag, yielding the increased melting temperature and viscosity of the slag. On the other hand, H2 accelerated the carburisation of the reduced iron by CO gas, enabling the homogenisation of the oxide materials to form a liquid phase. Therefore, it is considered that introducing H2 in the reactor is helpful to increase productivity and energy efficiency by accelerating the liquid phase’s formation.

Aug 21, 2024

The coking coal produced by Utah Development Company in the Bowen Basin is processed by a dual system of dense media cyclones for the 30mm x 0.5mm feed and flotation for 0.5 x 0mm material. The basic metallurgy of these processes will be presented with emphasis on the operational characteristics which are peculiar to coal. Potential areas for process improvement by the application of more sophisticated control systems will also be discussed.

Jan 1, 1978

By Dunn P. G

The copper ore reserves at the Chuquicamata mine were re-estimated during March to June 1994, as part of a comprehensive audit of the mine's overall short- and long-term planning. The basic principles essential to all ore reserve estimates were implemented viz: 1. A detailed study of the geology, in this case particularly of the orientations of structural features of copper mineralisation and the subdivision of the orebody into geologically homogeneous sections, 2. the use of both drillhole and blasthole data sets, 3. statistical and geostatistical analyses of both data sets to model anisotropic spatial structures for all the geologically homogeneous sections, 4. block kriging using both data sets individually; and 5. a comprehensive validation of the block valuations to confirm the absence of global and conditional biases and to quantify the actual improvement achieved in the overall quality of the estimates compared to those executed on earlier techniques.

Jan 1, 1995