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Modelling and Optimisation of Direct Reduction of Iron Ore by Coal in a Rotary Kiln

Sep 13, 2010

By C Vuillier, A Roshdieh

Water is the main medium for removing impurities from iron ore during wet processing to achieve a higher quality product. However, there is a substantial increase in freshwater consumption due to an increase in demand from the following two factors: in the past 55 years the world population has doubled from 3 to 7.5 billion and crude steel production has increased five times from approximately 350 to 1662 Mt/a (IISI, 2008). Furthermore, social development in developing countries exacerbates water consumption making freshwater an increasingly valuable resource with an average distribution of 70 per cent for agriculture, 20 per cent for industry and only ten per cent for domestic consumption (Hourtolle, 2005; OECD, 2009). Rapidly changing regulations over the access and preservation of water across the world indicates the growing importance of this issue, so the mining industry must adapt to this continual change and must be committed to increasing the efficiency of water usage.Tailings dams receive most of the water used by the process plant. In arid regions where evaporation is high and availability of water low or non-existent, technical solutions other than the conventional tailings dam, such as thickened and/or filtered tailings, exist to optimise the recovery of water and reduce the need for external water consumption. However, these solutions present additional challenges, such as energy consumption and transportation from the process plant to the ultimate storage area.This paper considers a range of alternatives covering thickening and filtering, transportation and storage, water return, closure and rehabilitation. Mining projects in the future will be more affected by the rising cost in water and tighter regulations in accessing water and energy. Good tailings management can contribute significantly to reducing the dependence on these two key commodities (water and electricity), improving the resilience of iron ore projects especially in arid regions and areas with high competition for water.CITATION:Vuillier, C and A Roshdieh, A, 2017. Minimising the water loss associated with mine tailings disposal, in Proceedings Iron Ore 2017, pp 245–250 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

The smelting of the Broken Hill lead concentrates at the Broken Hill Asso,ciated Smelters produced, among other products, approximately 4,900 ounces of gold and 8,800,000 ounces of silver during the year ending June 30th, 1938. The following table shows the actual amounts of gold per ton of lead concentrate produced during this period at the important mines. The total gold in the period is calculated from the number of tons of lead concentrates produced, and by comparison with the production' of silver, shows thatthere is no constant relation between the amounts of gold and silver.The fact that no gold is seen during milling, even when gravity concentrating tables are employed, signifies that the gold does not occur as occasional coarse particles.Further, as the values increase considerably in the flotation slime, it can be inferred that the gold occurs as minute inclusions in one or more of the minerals in the lead concentrates.The four most abundant minerals in the lead concentrate are galena, zinc blende, chalcopyrite, and...

Jan 1, 1940

By A J. Eggers

With gold first discovered at Carrick in 1864, exploration and mining on the Carrick Goldfield in Central Otago, New Zealand, has now been ongoing for more than 130 years. Recorded historical hard rock production from up to 52 different mining claims from 1864 to about 1921 is 24,047 ounces (oz) of gold.   Since 1980 Amoco Minerals New Zealand Limited, CRA Exploration Pty. Limited, Amax Gold Mines New Zealand Limited and Summit Gold (New Zealand) Limited have conducted modem systematic exploration campaigns targeted at locating shear controlled gold bearing quartz lodes and stockwork deposits. More than NZ $1million has been spent by these companies on aerial photography, geological mapping, stream sediment surveys, soil and rock chip geochemistry as well as reverse circulation (RC) percussion and diamond drilling.   RC drilling by Summit Resources in 1997 has identified a 1,500 m long zone of low-grade gold mineralisation at Lower Carrick, with an average grade of 1.00 g/t Au over a 14 m average thickness. This gold mineralisation, hosted within a low angle shear zone, has analogies with the Hyde-Macraes Shear Zone in eastern Otago. Recent exploration and drilling at Carrick has revealed the potential to discover large (>0.5 million ounce (Moz)) low-grade bulk shear controlled quartz vein and stockwork gold deposits similar to those now being mined at Macraes.

Jan 1, 1997

By R J. Worland, D Bowyer, J L. Mauk

The TerraSpec is a compact field portable mineral analyser that uses non-destructive reflectance spectroscopy for mineral identification. The instrument uses and measures infrared and visible light that is absorbed by certain covalent and molecular bonds (AlOH, FeOH, MgOH, CO32-, OH, H2O and NH4) within the lattice of a mineral at specific wavelengths producing an absorption spectral profile. A variety of minerals can be detected including clays, micas, carbonates, and hydroxides as well as some sulfates and silicates. However, not all minerals are detectable, such as quartz and feldspar. Alteration minerals replacing volcanic rocks have been studied for several epithermal prospects in the lower Waitekauri Valley (Sovereign, Jubilee, Scotia and Jasper Creek) and a geothermal field in the Taupo Volcanic Zone. At the Sovereign, Jubilee, Scotia and Jasper Creek prospects previous XRD investigations determined well developed clay mineral zonation with illite in the west (Sovereign and Jubilee) grading into interstratified illite-smectite (Scotia) and smectite (Jasper Creek) to the east. Although the percent of illite within interstratified illite-smectite could not be determined and some illite-rich illite-smectite (>90 per cent illite) and some smectite-rich illite-smectite (>90 per cent smectite) could be misidentified as illite or smectite respectively, the TerraSpec survey determined the same zonation of illite to illite-smectite and smectite. Common chlorite, rare calcite and local kaolinite were also detected. At the geothermal field, the TerraSpec was primarily used to determine the occurrence of kaolinite, dickite and alunite, which form in acid conditions. Widely spaced (every 50 to 100 m) XRD results are in excellent agreement with closely spaced (every 5 to 10 m) TerraSpec results that further determined the occurrence of these minerals in previously unrecognised intervals. It also determined the occurrence of zoned smectite, illite-smectite, illite, and chlorite alteration. Overall, the TerraSpec is a rapid mineral identification technique that is very useful in delineating the occurrence and distribution of certain minerals in both epithermal deposits and geothermal fields. Although the TerraSpec cannot detect as many minerals as XRD, the TerraSpec allows data collection at a sampling scale and speed (real time) that is not practical by XRD.

Jan 1, 2006

By M Warnken

Major cities are not only the focal point for AustralianÆs work, leisure and homes, they also are the focal point for the flow of resources into the built environment, motor cars and transportation and urban consumables. The steady increases in æstockÆ and waste generation, in line with GDP growth, means that cities will become the mine sites of the future if the inherent value is recovered from these materials at end of life. The urban waste stream can be characterised as containing approximately nine per cent hydrocarbon-based materials; 57 per cent biomass-based material; 28 per cent fully mineralised materials that are inert, five per cent metals and less than one per cent of problematic materials that are potentially hazardous and toxic. In order to convert these wastes into value added inputs into the economy, a number of technological interventions are required. These æurban waste mining techniquesÆ revolve around source separation and material streaming. One issue that needs to be overcome when determining which mining technique to implement, is identifying the option that will deliver optimal value, both from a financial and a sustainability perspective. The difference between embodied energy and calorific value is a case in point. Highest net resource value (HNRV) is a concept that can assist in choosing between different resource recovery options. The assessment can be done at a strategic level, or can be used to work out material specific issues. For example, used tyres can be recovered for their energy content at an approximate cost of $120 per tonne, whereas mechanical processing of used tyres can deliver a net benefit of $192.

Jan 1, 2006

Author's Note: Since the paper on "All-Flotation at North Broken Hill Limited" was read and discussed, the metallurgical results obtained have conclusively justified the adoption of the All-Flotation treatment.At present the shipping grades of lead concentrate produced from North mine ore range between 74% and 75% Pb, carrying approximately 43 oz. Ag and 4.5%-5% Zn. The lead recovery in lead concentrate is recording 95%-96% of the lead content of crude ore, and the milling and treatment cost on 6400 tons crude ore perweek of 96 hours has dropped to 6s. 3.6d. per ton on ore. With an increased ore tonnage, and with a new mill, considerable further reduction in costs is certain.New flotation machines, with 30 in. vertical depth of overflow (instead of 42 in. depth), are now being tried for the secondary granular treatment, with advantageous results. The treatment to-day is practically the same as that outlined in the paper, excepting that additional concentrate is returned for retreatment in the existing units.(Signed) A. LOWRY.Mr. T. A. READ: The author states (page 356 of Proceedings, No. 79), "The sulphide ore itself was then comparatively coarsegrained, a fact which permitted ready concentration of the galena contents by means of jigs, tables, vanners, etc."

Jan 1, 1931

By N van Aarde, B A. Moore, S van der Merwe

Frequently materials handling operations are compromised by transfer chute problems ranging from high wear rates, blockages and ineffective loading of the downstream conveyor. This paper will present the design flow implemented to overcome problems in two case studies utilising discrete element modelling incorporating material characterisation.Material testing is relevant in achieving a valid discrete element method (DEM) simulation model and subsequently a valuable design tool for transfer chute assessment and design. It is well recognised that in the current growth and demand for mineral resources, leading to ever increasing conveyor capacities associated with export terminals and mineral processing facilities that transfer chutes are a key focus point. The successful performance of the transfer chute is also dependent on operating with a ærobust rangeÆ of material flowability and handling characteristics. This requirement is crucial in accommodating mineral ores from developing resources, which are often more friable and stickier than in past decades.This paper will include details of chute installations associated with iron ore and coking coal, from the DEM simulations through to the performance of the installed and commissioned plant.CITATION:Moore, B A, van der Merwe, S and van Aarde, N, 2013. Implementation of advanced transfer chute designs, in Proceedings Iron Ore 2013 , pp 445-450 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

Uranium ore at Sleisbeck, N.T., occurs as lenticular bodies associated with zones of bleached carbonized schists lying between walls of closely folded quartzite. The ore consists mainly of uranium micas with Borne pitchblende.INTRODUCTIONThe Sleisbeck uranium prospect is about 70 miles E. of Pine Creek, and 160 miles S.E. of Darwin (Fig. 1). The prospect consists of a well-defined, E.-W. trending line of hills, about I! miles long. The line is composed of 3 major hills called the Eastern, Central and Western hills, with minor interconnecting hills and outcrops (Fig. 2).

Jan 1, 1955

The ore, as sent to the sulphide mill, is a mixture, in varying proportions, of oxidized ore from above the 450-ft. level and sulphide ore from above and below (to date mainly from above) that level. The oxidized ore consists essentially of quartz, with varying amounts of kaolin and clayey material which passes into the slime and, in excess, creates a serious problem in settling. Pyrite may be present in small amounts. The gold is free and extremely fine.The ore, classed as sulphide, consists of pyritic material in a quartz gangue. The sulphides have been exposed to weathering, leaching by descending solutions and attack by ascending gases and actual burning. The alteration products occur in widely varying proportions and this variation adds to the difficulties in settling and control of grinding and flotation.Copper Minerals.-Chalcopyrite is the principal copperbearing mineral with smaller and varying amounts of covellite, which is sometimes associated with chalcocite, both these minerals being apparently of secondary origin.Examination of tailing by Dr. Stillwell has revealed all stages between clean chalcopyrite, chalcopyrite tinged with covellite, covellite with residual cores of chalcopyrite and clean covellite.The chalcopyrite is free floating, very few particles of clean chalcopyrite being observed in the tailing from granular flotation. The chief tailing loss is probably as chalcopyrite occurring as small inclusions in pyrite...

Jan 1, 1939

With some notable exceptions, marine placers located just below, or just above, present sea level, are responsible for much of today's production of detrital ilmenite, rutile, zircon, and other minerals of value. The purpose of this paper is to discuss the paleogeographic and paleo-oceanographic factors which may have determined the location of presently submerged marine placers. These factors include changes in sea level, burial by recent marine sediments, stream capture and other changes in drainage patterns, and recent changes in climate. Selected geologic situations in the Yellow Sea off the coast of Korea, in the Atlantic Ocean off the coast of Portugal, in the Bering Sea off the coast of Alaska, and in the Arabian Sea off the coast of India, will be used to illustrate the author's point of view.

Jan 1, 1971

The notes from which this paper has been prepared were set down at the time of the author's departure from Australia in 1935. Mr. Frank Forman, Government Geologist of Western Australia, who has very kindly read the paper in manuscript, affirms that the views here set forth are now accepted by most geologists. Thus, Forman's recent presidential address before the Royal Society of Western Australia (1937) mentions sediments in the Kalgoorlie Series "including banded jaspers and jaspilites."While it may, therefore, be superfluous to belabour the question further at this time, Mr. Forman has encouraged the author to publish this paper as a summary or both past and present views.To those specially interested in the subject of the paper, a study of pertinent Plates attached to Western Australian Geological Survey Bulletin No. 71, 1917, is suggested.The type of rock which is variously called "jasper bar," jaspilite, or "ferruginous quartzite" is familiar to all mining men who have worked in the West Australian goldfields.In its typical form it is a "striped" rock consisting of alternate layers of white or pinkish silica with red to brown bands of iron-bearing silica.In the course of geological work in many parts of Western Australia I studied exposures of jasper bar and was repeatedly impressed with the similarity of much of the material to the sedimentary "banded iron formation" of Canada. It was, therefore, a surprise to learn that the jasper bars were not generally regarded in Australia as sedimentary horizons. It is true that Honman offered convincing evidence of the sedimentary origin of the jaspers...

Jan 1, 1939

The zinc-lead lode at Rosebery, on the West coast of Tasmania, has a total length of over 4000 ft. It consists of five elongated lenses parallel to the foliation planes of the quartz sericite schist, and is situated at the junction of the quartz sericite schist and a thin belt of slate. The lenses consist of massive, fine grained sulphide ore, with small amounts of quartz, barite, sericite and chlorite, and they terminate in masses of low grade ore. The gangue minerals increase in quantity in the low grade ore which includes small quantities of the manganese garnet, spessartite. The schist walls of the lenses are in places impregnated with lode minerals to a degree sufficient to permit them to be regarded as economic ore.The ore-bodies have developed from incoming mineral solutions by the replacement of the quartz sericite schist and are localised where the ore solutions have been confined by a relatively impervious slate band. The early stages of replacement of the schists are signified by the development of pyritic bands which are succeeded by a strong development of zinc blende. With ptogressive crystallisation, the character of the mineral solutions gradually changed and the development of galena, and its associated bournonite, became more important in the later stages.Remnants of the replaced schist, in the form of isolated wisps and schlieren of sericite and chlorite, are present in the ore body, more noticeably in the pyritic specimens. An important feature of the ore is the association of small ogllantities of gold with trahedrite.

Jan 1, 1934

The suitability of char from Yallourn brown coal as a filler for carbon electrodes used in the aluminium smelting industry has been assessed on the basis of the specifications usually laid down by electrode manufacturers for petroleum coke fillers. The purity specifications can be met by a simple acid leaching of the coal before carbonization. The true density of char produced at 1200°C is within 5 per cent of the specification figure, but the bulk density of char obtained from as-mined coal is only half that specified for petroleum coke.Although this can be increased to three-quarters of the specified figure by briquetting the coal before carbonization, further increases would be very difficult to achieve, as the remaining shortfall in density is due to an extensive microporosity developed in the particles of char during carbonization.

Jan 1, 1970

The use of walk-through inspections, approvals and ad hoc investigations to ensure risk is kept within acceptable levels is reaching its limits of effectiveness. Further improvement in occupational health and safety requires a systems approach, and the use of Quality Management principles is an obvious basis for this. SafeGuard, a æbest practiceÆ model health and safety management system and audit criteria based on AS/NZS ISO 9001:1994, has been produced by the Department of Mines and Energy. Quality style audits of mine and quarry health and safety systems are now being carried out by the Inspectorate.

Jan 1, 1998

Future metal prices play a direct role in both the economic evaluation and short to medium planning of a mine scheduling sequence. It is difficult to predict with accuracy the future price of volatile metal commodities, however, it is possible to fix some future metal price, outside of long term contracts by the selling of futures contracts through a commodities exchange. The futures contract represents a fixed amount of a specified quality of a commodity for future delivery at a predetermined price. Several different types of hedging are possible, one in particular which is best suited for mining companies. There are relative advantages and disadvantages when trading in futures contracts and particular reference is made to gold contracts on the Sydney Futures Exchange.

Jan 1, 1980

he Wyalong goldfields were discovered in September, 1893, Messrs. Neeld and Sons, owners of the principal mine, being the pioneer prospectors. During the earliest days of the field the ore was sent to Barmedman, a distance of eighteen miles, for treatment at a battery there. The field rapidly increased in importance, and it was not long before a public battery was established on the spot. After some considerable quantity of ore was treated by this process, it became apparent that battery treatment was quite unsuitable for the richer ores, involving, as it did, considerable loss in the tailings. Recognition of this fact led to the erection, in 1895, of plants by the Wyalong Chlorination and Cyanide Works, owned by Mr. Walter Sully, for treatment by their processes; followed, at a later date, by Messrs. Neeld and Sons Chlorination Works. The Wyalong Chlorination and Cyanide Works, after a delay of twelve months in the erection of their plants, have since catered continuously up to the present time for the requirements of the field.Their plant consists of a No. 3 Gates' rock·breaker, a revolving dryer, a No. 5 Krupp mill, revolving roasting furnace with finishing hearth, two chlorination vats of 20 tons capacity each, "nine cyanide vats of 30 to 100 tons capacity, two Wheeler pans and three chlorine generators. The ores are purchased outright on assay at a fixed scale of charges, and treated by the owner of the works on his own account.

Jan 1, 1903

Gold rush histories are usually written as though they were unique events in the development of a region or nation. While this is a valid way of looking at gold rushes, it is not the only way. This paper is a brief attempt to relate the West Coast rushes to a wider context. During the second half of the nineteenth century the lure of gold transformed the Pacific Rim. Gold rushes drew more than half a million Europeans and Americans to lands bordering the Pacific. By 1900 a chain of mining, industrial and urban centres ran from California to Alaska; from Ballarat to New Guinea, and on to Western Australia. The New Zealand rushes were a significant chapter in this story. People, cargo and information passed from rush to rush. Techniques learned on earlier goldfields were imported; those developed in New Zealand were, in turn, taken up elsewhere. Administrative systems and regulations developed in Australia were implemented in New Zealand, improved and passed on to Canada. This interconnectedness was so strong that gold-seekers thought of the mining regions as a distinct culture, 'the whole digging world'. Much can be made of the similarities shared by rushes. But comparison can also highlight the individuality of each rush. +The early days of the West Coast rushes were perhaps the strongest assertion of a diggers' culture. A brief period in which a remarkable orderliness was created through mateship, self-regulation, and the occasional threat of rough justice. The West Coast rushes were both a unique experience and an integral part of a process which transformed the Pacific Rim during the nineteenth century. Understanding their part in that bigger story highlights just how unique they were.

Jan 1, 1996

By R Crookes

Mine to Mill optimisation is not a recently developed concept. It is one which is finally gaining greater acceptance in the Australian Mining Industry, possibly as a consequence of the downturn in markets and certainly made possible by the development of tools and techniques to measure and predict performance of mining equipment and milling plants. Fragment size after blasting has a major bearing on the performance of all aspects of mining and a major influence on the economics of the mine and mill. The process to optimise fragmentation consists of identifying the key factors, measuring their sensitivity through a modelling and trialing program and conducting economic evaluations on the changes on both the mine and mill. Management of the Ernest Henry copper-gold mine in NorthernQueensland, Australia, has espoused the Mine-to-Mill concept and isactively pursuing excellence in blasting to drive down the total cost of mining. Ernest Henry has extremely hard, wet and heavily jointed geological conditions, and had high powder factors and a large percentage of oversize material reporting to the crusher or ROMstockpile. A blasting improvement program was undertaken betweenErnest Henry Mining, Thiess Contractors and Orica Explosives tooptimise the ore size distribution, particularly the oversize component, as a step to reducing production costs. Measures of success included bringing the rock breaker back from double shifts to part-time operation and increasing direct dumping into the crusher from 70 per cent to 92 per cent. Tools and technologies to predict and measure the performance ofindividual blasts are needed before it is possible to optimisefragmentation or the downstream processes. These include suchspecialised Orica Explosives tools as SABREX, POWERSIEVE, andPOWERLINE and commercially available drill monitors. As importantare the more common still and video camera, borehole loggers,measuring tapes, surveying equipment such as face profilers, and ahigh-speed camera if possible. There are many tools which can be applied however it is rarely necessary or possible to use all of them due to time constraints and a point of diminishing returns. The critical point is knowing what the true parameters of the blast were compared to design - only then can the predictive tools be effectively utilised. Stage one of the program has seen gradual improvement as theunderstanding grew and practices have been implemented resulting inreduced bridging in the crusher, geological mapping with respective blast designs and the oversize component under control. This paper is about a process approach which links tools and technology to understand the fragmentation drivers and then to optimising the size distribution.The continuous improvement program continues...

Jan 1, 2000

By Branagan D. F

The geology of the area studied is briefly described, together with the prospecting methods used in the search for copper, lead, zinc and uranium ore bodies.Four prospects, Mt. Corella, Yanasinga, Lawlor's and Greenmount, which were diamond-drilled, are described in detail and geochemical results are discussed in relation to the mineralization found. Copper anomalies were found wherever intrusive rocks were mapped, and showed a much closer relation to geology and mineralization than did the predominantly lead and zinc anomalies.Geochemical prospecting aids in the overall mineral search programme because of its speed and economy, as it helps to pinpoint areas worthy of detailed geological examination. Geochemical anomalies are a guide to favourable zones but may not indicate the presence of ore.INTRODUCTIONDuring 1953-55 the National Lead Company of New York carried out a search for minerals in an area south and west of Cloncurry (Fig. 1) in rocks of Precambrian age. After reconnaissance mapping, a number of prospects were chosen for closer examination by detailed geological mapping and geochemical sampling, and from these prospects, five sites were selected for drilling.This paper records the salient features of the exploration programme and discusses the geology and geochemistry of four of the prospects-Mt. Corella, Yanasinga, Lawlor's and Greenmount. Practically all the prospects examined showed high zinc "anomalies" or "dispersion" trains. Greta, Mt. Corella and Lawlor's prospects showed some copper anomalies and, to a lesser extent, lead anomalies. In particular, Greenmount exhibited striking copper anomalies.

Jan 1, 1960