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By O Pasca, B Hogg

Consistent slag blow end point detection remains one of the challenges in the Peirce-Smith converters at Mount Isa MinesÆ Copper Smelter. Under blowing results in foaming on copper blow and carry forward of oxide skims to the anode furnace. Over blowing results in high copper losses to the slag. Both present safety issues and contribute to lower copper production. The end points of the slag making phases are assessed by inspection of a bar sample. A bar sample is a thin accretion layer that adheres to a steel bar when it is inserted into the tuyere while the converter is blowing. This method is biased and subjective, so there is heavy reliance on operator experience. The Semtech Optical Process Control (OPC) system was installed in early 2002 for converter slag blow end point detection. Initial plant trials did not improve all aspects of converter operations, and uptake by operators was poor, so the system was not used. In early 2005, the Semtech OPC system was re-visited and another short trial was conducted to evaluate the permanent use of the system for slag and copper blow end point detection. During this trial, the Semtech OPC method was found to be superior to bar sampling for slag blow end point detection. The implementation and refurbishment of the Semtech OPC system has resulted in plant improvements and given a better insight into converter operation during blowing. Oxide skim generation carried forward to the anode furnace has been shown to decrease with increasing compliance with Semtech OPC. Some of the expected improvements to converter operation were not found to be significant. Semtech OPC is now well received and utilised by converter operators. Individual paper available only. Not included in book or CD ROM Proceedings.

Jan 1, 2005

By S van der Sluijs, M van Ende, Y Tang, A Emami

This paper presents a phenomena-based model for investigating the possibility of scrap melting in an Open Slag Bath Furnace (OSBF) for green ironmaking. The goal of this study is to enhance the circularity of the steelmaking process by utilising scrap as a green source of iron in OSBFs. The model takes into account the fundamental differences between OSBFs and traditional processes such as Electric Arc Furnaces (EAFs) and Basic Oxygen Furnaces (BOFs). The model considers three primary regions where scrap heating and melting occur: the solid feed pile, slag and hot metal. It accounts for factors such as the furnace geometry, scrap charging mechanism and specific heat and mass transfer properties of the reactor. The model was validated using literature data and was used to investigate the heating and melting behaviour of individual scrap particles under various process parameters. The study finds that the scrap melting process in OSBFs involves three stages: shell formation, shell remelting and subsequent melting of the parent scrap. The carbon content of the scrap and the liquid hot metal plays a critical role in determining the melting behaviour. Depending on the carbon concentration and temperature, the melting process can be heat transfer controlled or mass transfer controlled. The paper also examines the scrap feeding methods in OSBFs, including direct charging into the slag or charging through a feed pile. The model provides insights into the melting rate of scrap compared to Direct Reduced Iron (DRI) in OSBFs and highlights the role of carbon in this process. Overall, this phenomena-based model contributes to the understanding of scrap melting behaviour in OSBFs and provides valuable insights for optimising the circularity and efficiency of green ironmaking processes. The findings of this study can inform the design and operation of OSBFs, paving the way for increased utilisation of scrap as a sustainable feedstock in the steel industry.

Jun 19, 2024

The Broken Hill (BH) Block contains a wide variety of mineralization, with comrodities including Pb, Ag, Zn, W, Cu, Co and Sn. Much of the mineralization is stratigraphically controlled. Fe, Cu and Co-rich mineralization is dcminant in the Thackaringa Group; Pb, Ag, Zn and W is dcminant in the BH Group and Sn mineralization is present above the BH Group. Some mineralization occurs as concordant syngenetic deposits, but other types have been partly or completely remobilized by metamorphism, magmatic activity or hydrothermal fluids. Almost all of the non-syngenetic mineralization, including stratabound, vein and intrusive-related types, has formed from the "recycling" (remobilization and redeposition) of metals originally deposited with the sediments and volcanics of the Willyama Supergroup.

Jan 1, 1983

By E R. Ramanaidou

The value of Raman spectroscopy to undertake mineral and chemical characterisation of iron ores was assessed by applying the technique to representative samples of banded iron-formations (BIF) and a BIF-derived, martite-goethite ore. The common iron oxides haematite, magnetite and goethite as well as gangue minerals such as quartz and carbonates all show distinct Raman spectra that enables these phases to be easily detected and mapped in situ for either samples prepared as polished blocks or unprepared material. Raman spectroscopy also offers the potential of in situ chemical characterisation. Shifts in the excitation bands of carbonate detected in BIF were related to the Mg content of Fe-carbonate and confirmed the first world-wide occurrence of a high Mg-bearing siderite (pistomesite) in BIF.The discriminatory power of Raman spectroscopy coupled with the potential of the technique to offer large-scale (volumetric) characterisation of iron ore will be of great value not only to the existing BID and CID ore types, but also to the newly emerging magnetite iron deposits (MID).

Jul 11, 2011

The earliest suggestions that some metallic ore deposits might have resulted from seafloor volcanic exhalation seem to have been those of Elie de Beaumont in 1847 and Henry de la Beche in 1851. In 1885 Tinoco, and Bouglise and Cumenge, independently investigating-.the manto copper deposits of the Boleo district of Baja California, proposed that these had formed on the seafloor by precipitation from "hydrothermal submarine emanations". Some twenty years later the Japanese geologists Kukuchi and Tsujimoto (1904) put forward the idea that the Kuroko ore- bodies were seafloor volcanic sinter deposits and in 1919 this was re-affirmed by Ohashi. In 1909 the English geologists Thomas and MacAllister postulated a similar origin for some of the gold deposits of Mount Morgan in Queensland. Between the wars the great European economic geologists Niggli and Schneiderhohn both clearly recognized a class of seafloor hydrothermal deposits. The idea rose again immediately after the Second World War in a very clear statement by Hegeman in 1948, which was followed by contributions by Ehrenberg and Kraume and their co-workers on the submarine volcanic origin of the Meggen and Rammelsberg orebodies in 1954 and 1955 respectively. In 1955 the present writer, quite unaware of early or contemporary work on volcanic exhalative ore deposits, proposed a volcanic sedimentary/diagenetic origin for the stratiform base metal ores of SE Australia. In doing so the writer emphasized the probable importance of island arc volcanism, suggested that some "metallogenetic regions" of ancient terrains were in fact old island arc systems, that the composition of the ores might be related to the composition of the associated volcanic rocks and that such ores would be tied to volcanic stratigraphy. Ideas on relations between volcanism and stratiform ore genesis have thus been evolving over.a period of some 140 years and, beginning with the observations on Baja California in 1882, work round the rim of the Pacific has made an important contribution over a period of more than 100 years.

Jan 1, 1987

By J Nixon

I have to say that my story is not too much different to many others who grew up and worked in the great mining fields like Broken Hill, Mt Isa, Rosebery, Kalgoorlie or Kambalda and any one of them could have stood up here and spun you a good yarn.What does my paper offer you in this volume? By sharing my experiences I want to encourage you to consider your own experience with leadership, taking on change, learning from and contributing to the development of others.I have been very fortunate to be part of many new innovations into underground mining over the past 40 or so years; most of it with Conzinc Rio Tinto Australia (CRA)/Rio Tinto operations.•From hand-held drills and a homemade single boom Jumbo mounted on an old Airtrak, to the sophisticated twin boom jumbos with high speed drifters all controlled by an on-board computer;•from a Scraper winch and a Wagner 2D loader to fully automated electric LHDs that navigate to the tipple, empty the bucket and return to where they come from;•from hand-held cut-and-fill and timber stoping in Broken Hill to the bulk mining methods of a block cave where at Northparkes we mined more ore in a month than we mined in the total five years of operations at Currawang;•from hand-held scaling and bolting with no skin protection to installing ground support with Jumbos and sophisticated Cable Bolters and the introduction of in cycle shotcrete;•from hand-held ladder rising and shaft sinking to Box Hole rigs, Raise Bore Machines and Blind Hole shaft sinking; and•from Gelignite based AN60 stick explosives, ANFO, fuse firing and half second detonators to Powergel, Emulsions and electronic computer programmed detonators that can somehow be initiated by ‘Blast Ped’ travelling through the rock.

Mar 21, 2011

By LefTvre Y

In May 1991, AZSA commissioned a new conventional Cell House. This paper focuses on the major improvements introduced in the design and the construction of the equipment, machinery and control. An effective control system together with good reporting and routine operation has resulted in quality control of the Cell House at the highest possible level. Consequently the monthly current efficiency consistently averages above 93 per cent with a total energy usage of 3000 AC kWh/t of cathode zinc. The new concept for the year 2000 and beyond is introduced.

Jan 1, 1993

By R C. Morris

Two major types of economic secondary iron ores occur in the banded iron formation (BIF)-rich Hamersley Province of the Pilbara, Western Australia:dominant BIF-hosted bedded iron deposits (BID)detrital ore deposits (DID sensu lato), which are mainly hosted in the three province-wide Cenozoic sequences that include coeval non-ore sediments and comprise:a. the major Miocene, fluvial channel iron deposits (CID)b. the lesser Eocene and Pliocene detrital iron deposits (DID sensu stricto).Striking differences exist between the massive CID resources and the much smaller underlying and overlying DID. CID are essentially riverine alluvial ooidal rocks with abundant small fossil wood fragments and variable iron peloids, but with only extremely rare recognisable lithic remnants. The original matrix is typically ramifying layered goethite. Eocene DID are mainly alluvial with minor pisoids, whereas Pliocene–Quaternary DID are dominantly coarse colluvial gravels, both derived from and largely retaining the original textures of BID, hard cap or variably ferruginised surface BIF. The colluvial DID matrix is typically ferroan-aluminous soil, resulting in canga where replaced by goethite, which may be dehydrated to hematite by exposure. The Cenozoic deposits occur in two dominant geomorphological environments: the southern Marra Mamba to Brockman Iron Formation strike valleys containing all three Cenozoic sequences and the much later northern Brockman Iron Formation plateau valleys that include only the Miocene and Pliocene sequences. The Cenozoic detritals formed in different climatic regimes, with an extended dry period forming a prominent province-wide dehydrated carapace on the Eocene DID. The Miocene ‘optimum’ followed with its thick scrub-covered deep regolith that produced the fossil wood-rich CID and was succeeded by the arid cool period of the Oakover limestone/calcrete. A major renewal of exposure and erosion in the Pliocene resulted in the extensive iron gravels of the Pliocene–Quaternary.CITATION:Morris, R C, 2015. The Cenozoic detrital iron deposits of the Hamersley Province of Western Australia – a tribute to Mal Kneeshaw, in Proceedings Iron Ore 2015, pp 319–326 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

The building is a lofty, well-ventilated one of hardwood frame, with galvanized-iron walls and roof, and consists of five spans running north and south, covering a total length of 236 ft. Each span is composed of nine bays of 1:3-ft. centres, making the total width of the building 117 ft. The refinery is situated conveniently at a distance of 100 yds from the smelters. Through the third span of the building runs a 5-ton electric overhead travelling crane, of a 3-motor type, with a span of 29 ft. The crane runway extends over a railway line, which connects the smelters to the refinery. This crane is llsed for handling bullion, coal, melting kettles, lead pumps, &c. A 3-ton crane of similar type, but with a 50-ft. span, runs through the fifth span of the building and also extends over the railwav line alreadv mentioned. This crane is used to load the soft lead into railway trucks, or to stack lead awaiting shipment in the area covered by the crane's operations.

Jan 1, 1918

By L Mariano

Three selected iron ore samples from the major bedded and channel iron deposits of Western Australia were analysed using a scratch test commonly used in the oil and gas industry. The portable commercial equipment dubbed Wombat cuts a groove on the surface of the sample with a cutter under imposed depth of cut and cutting velocity. The normal and tangential components of the force acting on the cutter are recorded with a high degree of precision (about 1N) at fine spatial resolution of about 20 measurements per millimeter.The intrinsic specific energy inferred from the scratch test measurements is found very well correlated with a classical measure of strength such as the uniaxial compressive strength, for over 300 sedimentary rock samples.The results obtained on the iron ore samples are comparable to those obtained on oil and gas sedimentary rocks. This method could provide an objective and semi-automated measurement of material strength and brittleness in iron ores that can possibly be correlated to the lump to fines ratio.

Jul 11, 2011

At Bulong, the mineralised (>0.8 per cent nickel) ore exists within numerous lithologies, which can and do occur coincidently. It is very important to discriminate between the different host units for estimation purposes, stockpiling and scheduling. This allocation of host unit has relied upon visual interpretation by the geologist recording the information, which can be very subjective by its nature. By using quantified constraints, such as assayed magnesium oxide and iron, the subjectivity of describing the host material of nickel laterite ore is reduced. The constraints permit consistent identification of the various host units, which improves the confidence in the overall estimation and scheduling of the ore.

Jan 1, 2000

By D A. Sketchley

The Merlin Zone, a 2008 high-grade Mo-Re discovery, is a part of the Mount Dore Deposit in the Eastern Succession of the Mount Isa Inlier in Queensland, Australia. Hosted by carbonaceous metapelites and phyllites, the Merlin mineralisation comprises molybdenite veins, breccia infillings, stylolitic fracture fillings, and disseminations. Because rhenium is geochemically similar to molybdenum and commonly associated with it, global production of rhenium has been mostly a by-product of molybdenum refining. The high-grade rhenium in the Merlin Zone is an exciting discovery that is expected to become a direct source of rhenium. At the time of discovery, quality assurance (QA) procedures for rhenium were not in place at the Merlin Zone; therefore, they needed to be developed.The Merlin Zone was discovered using reverse circulation drilling, which led to concerns about molybdenite loss due to poor sample recovery. The twinning of the discovery hole with diamond core demonstrated a two-fold increase in molybdenum grade over several tens of metres. Consequently, the resources of the Merlin Zone were defined using assays from diamond drill core.Early analytical work, which was initially done only for molybdenum, comprised geochemical analysis with an aqua regia digestion, which have poor precision and can be biased low. Although initial testing for rhenium used similar procedures to those for molybdenum, a scarcity of commercial rhenium reference materials led to a validation process using neutron activation analyses and different digestions. This resulted in introduction of four-acid digestion assays, development of matrix-matched reference materials, and improvements to the quality of molybdenum and rhenium assays for reporting resources. Coarse and pulp duplicates were used to check for sampling bias and to ensure that levels of precision were adequate for the style of mineralisation and analytical methods. In addition, the direct and consistent geochemical correlation between molybdenum and rhenium provided another method for checking analyses.

Aug 22, 2011

By J Coombes

Within the mining industry there is a growing trend of placing inexperienced technical people into positions of responsibility beyond their readiness. Their responsibilities often include providing the fundamental basis for decision-making: the resource model or even the daily grade control estimates. Whilst software continues to make the processes more accessible, the thinking and rationale for selecting parameters still requires control rather than auto-piloting. Operators run these systems in virtual isolation, and have limited immediate access to experts. Beyond the stress of the professional burden are the increased risks to the mining operations and overall project success.While many experienced experts recall being thrown in the deep end, the relative isolation from experts coupled with the gravity of professional burden before readiness, is less familiar. Many recall in intimate detail the experts who gave them direction, assisted them along the way and even helped them claw out of inadvertent mistakes. Experienced professionals all have a responsibility to enable capability across the generations, to ease the burden and to mitigate the risks.This paper provides an outline of how mentoring as an on-the-job professional development process can be structured to more fully enable success of a mentoring program. Three examples complement the principles presented.CITATION:Coombes, J, 2012. Structuring meaningful mentoring, in Proceedings International Mine Management 2012, pp 15-22 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

By M Ahler

Future developments in the mining sector will be driven by the need to increase safety, ecological sustainability and efficiency. Autonomous systems represent a huge step towards achieving these goals. This paper describes the basic infrastructure of an autonomous system – essentially a network of distributed sensors. Although the sensors are distributed, the overarching communication network with its related middleware offers a transparent and uniform layer. This middleware acts as an abstraction layer which priorities information and provides information to other platforms on request. This permits higher-level autonomous functionality to utilise all information available in the system regardless of where data has been generated or via which physical communication link it has been processed.The Personnel Proximity Detection (PDD) system is described in detail as an example, with details not only of the system itself, but also of the essential full integration and how the abstraction layer allows this technology to be plugged in at any location of the network. The paper ends with a summary of the content and a conclusion.

Nov 22, 2011

By Andersen AK

A previous paper (1) indicated that electrowinning of copper at current densities considerably higher than those currently employed in electrowinning operations is technically feasible. It is of interest, therefore, to establish the extent of economic benefits which may be obtained from high current density operation and to determine the value of the optimum current density. Optimization of electrorefining processes has been discussed in considerable detail by Ibl (2) and Schmidt (3) whop from theoretical considerations, derived expressions for the optimum current density. In this work, general equations relating both the capital investment and the production cost for copper electrowinning plants to current density and plant capacity are established. From these equations, the optimum current density can be calculated for any desired plant capacity.

Jan 1, 1969

By M Yahyaei, P Knights, M S. Kizil, J Qu

Digital Twins (DTs) are transforming business operations across many industries through their accurate representations of physical entities enabled by IoT technologies.

Sep 1, 2024

By D Carroll

Mining of the zinc, lead and silver deposit at the Broken Hill Southern Operations site has been occurring for over 100 years. As a result of this, a significant amount of high-grade ore is now taken from narrow remnant pillars left between old stopes and zones of previously mined ground. Stopes have been filled with either hydraulic fill (also known as ‘sandfill’), cemented hydraulic fill (cemented sandfill), waste rock backfill or a mixture of these fill types.In the last ten years, there has been considerable success mining through narrow pillars where sandfill is exposed in the development face and/or walls using a ‘shell’ support regime, wherein a layer of bolted mesh is sandwiched between two layers of sprayed fibrecrete (25 mm fibrecrete, then mesh and bolt, followed by a final 50 mm layer of fibrecrete). Shell support is also used in very poor, broken, relaxed ground conditions and in areas filled with cemented fill (sandfill with a minimum four per cent cement content).The next stage of innovation has been to develop a technique for mining through old stope voids filled with uncemented sandfill, known locally as ‘contours’ (old cut-and-fill working), an activity where unconsolidated sandfill can run at the face and from the backs. The challenge is to prevent exposed sandfill in the face and the backs from failing before it can be supported.To achieve this, the Southern Operations mine has implemented a technique in which 6 m long spiling bars are used to strengthen and stabilise the sandfill in front of the face. The hollow steel bars are driven in around the heading perimeter in a closely spaced pattern then pumped full of grout. The bars and the grout stabilise the sandfill in front of the face, preventing it from failing into the drive during excavation and prior to further support being installed.A final support system consisting of shotcrete, mesh, bolts and steel girders is installed as excavation progresses. Both the initial and final support systems are essentially passive support systems designed for a low-stress environment (as the stress originates mostly from the mass of unconsolidated sandfill).This process is slow and labour intensive. Fifteen separate cycles of people/machinery are needed to progress one equivalent heading cut (compared to six for a standard fibrecrete- and bolt pattern-supported rock face heading). This slow pace introduces scheduling challenges, but the process opens up parts of the orebody that were previously uneconomical to mine.CITATION:Carroll, D, 2014. Mining through sandfill using spiling bars, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 95–100 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By Alesse V, Belardi G

A new class of collectors, Mercapto-Benzo-Oxazoles (MBO), exerting selective action on copper sulphides in the presence of Pb, Zn and Fe sulphides (galena, sphalerite and pyrite), has been synthesised in co-operation with Enichem's Donegani Insitute. The collectors have a mixed aliphatic-aromatic structure and contain functional groups which form chelates with copper. Some reagents of this class having hydrocarbon chains of various lengths have been laboratory tested on a complex sulphide ore containing chalcopyrite, galena and sphalerite in pyritic gangue. Comparative flotation tests have permitted selection of the best collector for chalcopyrite, namely Methyl-Mercapto- Benzoxazole (MMBO). Systematic flotation tests have been performed with this reagent, varying collector concentration, grain size of the feed, pH and flotation time. The results obtained show that the synthesised collector is much better than potassium-amylxanthate (KAX) as regards selectivity towards Pb and Zn. Moreover, it is possible to work at natural pH (6-7) and the flotation rate is higher. In fact in the rougher stage with 80 g/t of collector at natural pH, a copper grade of 7.14 per cent was obtained with a recovery of 73.87 per cent, while the grade with KAX did not exceed 2.11 per cent for a recovery of 73.54 per cent. The amount of Pb and Zn reporting in the copper concentrate was eight per cent and ten per cent respectively, while with KAX it was no lower than 24.34 per cent and 22.71 per cent in that order. After two minutes flotation a copper grade of 5.2 per cent with 52 per cent recovery could be attained, against a grade of 2.5 per cent and a recovery of 44 per cent in the case of KAX. The efficiency of this new collector has been ascertained on two samples of complex sulphide ores of diverse mineralogical composition.

Jan 1, 1993

By G Hancock, J Lowry, W D. Erskine, D Jones, T Coulthard, M J. Saynor, P Lu

An 8 ha trial landform was constructed in late 2009 at the Ranger Uranium Mine, located 250 km east of Darwin in the wet-dry monsoonal tropics of northern Australia. The objective of the trial, which comprises two surface cover types on a uniform two per cent slope, is to provide long-term data to guide the development by Energy Resources of Australia Ltd (ERA) of its landform closure strategy. The scope of the work program for the landform includes many aspects; however, this paper is focusing on run-off and erosion rates. The run-off and erosion rates are used to assess the long-term geomorphic stability by comparing measured with modelled export rates from a landform evolution model.Monitoring of wet season run-off is undertaken collaboratively by the Environmental Research Institute of the Supervising Scientist (ERISS) and ERA, on four purpose-instrumented 30 m by 30 m erosion plots. Continuous measurements are made in rectangular broad crested (RBC) flumes located at the outflow of each plot, of water level, turbidity (a surrogate for fine suspended sediment) and electrical conductivity (EC) (a surrogate for solutes). Each plot has a tipping bucket pluviometer located near the RBC flume. Bed load is collected monthly.This paper reports the findings of rainfall and bed load from the first two wet seasons (2009 - 2010 and 2010 - 2011) following construction. The field measured loads will be compared with the predictions made by the Cellular Automaton Evolutionary Slope and River (CAESAR) landform evolution model. Initial results indicate that predicted rates of sediment export from the CAESAR model are similar to measured export rates. This provides confidence in the capability of the model to predict stability of the future rehabilitated mine area, especially during the critical initial years following construction. CITATION:Saynor, M J, Lowry, J, Erskine, W D, Coulthard, T, Hancock, G, Jones, D and Lu, P, 2012. Assessing erosion and run-off performance of a trial rehabilitated mining landform, in Proceedings Life-of-Mine 2012 , pp 123-132 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By N Kojola, A Vickerfält, J Huss

The possibility of using an acidic autogenous hydrogen direct reduced iron (H-DRI) slag as a basis for vanadium extraction is investigated. For a raw material to be suitable for producing high-quality FeV, the vanadium oxide content should be sufficiently high and the phosphorus oxide content in a tolerable range. Therefore, the feasibility for vanadium extraction relies on fulfilling two demands: the predominate partitioning of phosphorus to the metal and vanadium to the slag. Correspondingly, the behaviours of phosphorus and vanadium in the Al2O3-SiO2-FeOx-VyOz-P2O5-Fe system were studied experimentally. Slag, 10 g, was put in contact with liquid iron, 30 g, for different durations (2–24 hrs) in closed alumina crucibles at 1873 K. The slag composition was varied between 33.1– 49.3 wt per cent Al2O3, 27.1–46.7 wt per cent SiO2, 16.6–30.1 wt per cent FeOx, and 2.5– 8.8 wt per cent V2O3. The equilibrium phosphorus distribution was 0.42, while the vanadium distribution ranged from 7.6 to 43.4, increasing with the Al2O3- and the FeOx-content.

Jun 19, 2024