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By M Barley, C A. RosiFre, L Lobato

The Carajßs iron ore deposits contain approximately 17.5 billion tons of ore with >64 per cent Fe and occur in the eastern part of the Amazonas Craton. They are hosted by jaspilitic banded iron-formation (BIF) of the Carajßs Formation which, together with metavolcanic rocks, comprise the ~2.75Ga Grpo Parß Group of the Itacai·nas Supergroup in the ~1000 km long, E-W trending Carajßs Synclinorium. The Carajas Formation comprises discontinuous layers and lenses of partly dolomitised BIF (17 - 43 per cent Fe and 35 - 61 per cent SiO2) and lenses of high-grade iron ore, cut by mafic sills and dykes. The high-grade iron ores occur as large tabular bodies of friable (soft) hematite with smaller lenses of hard (compact) hematite. The hard hematite ores typically occur at the contact with the underlying volcanic rocks and are surrounded by an aureole of hydrothermal carbonate alteration. BIF that has been overprinted by dolomite and magnetite crystallisation has recently been discovered at depth in the N4E Mine. With increasing amounts of carbonate, the original lamination (microbanding) and other fine primary structures in the BIF have been progressively obliterated resulting in alternating carbonate and iron oxide mesobands. The friable hematite ore that is characteristic of the Carajßs deposits results from ongoing weathering and leaching of the carbonates from this type of altered BIF. The hard hematite ores probably result from more extensive early oxidation. The association of both carbonate-altered and jaspilitic BIF with the N4 Mine is similar to that observed at the Mount Tom Price deposit in Western Australia, where carbonate-altered BIF occurs below massive hematite ore with a jaspilitic halo developed above the orebody. This indicates that as at Mount Tom Price, hydrothermal carbonate alteration and associated loss of silica from BIF may be an important step in the formation of these giant hematite deposits.

Jan 1, 2002

By A Annor, L J. Chen

The production of paste backfill has typically been accomplished through the adaptation of existing technology. Thickeners and disc filters have several drawbacks when applied to production of tailings paste backfill. Personnel at CANMETÆs backfill research laboratory in Sudbury, Ontario, Canada have been carrying out research into and development of methods to produce paste backfill using total mill tailings since 1991. Using a silo for production of paste is not a new concept but has been refined to a marketable level. This technology is based on a fluidization principle that assists in settling the tailings to an homogenous state in a silo. Other developments include patented de-watering technology for use in the silo to speed the settling of the solids to a suitable solids content, optimisation of silo geometry, and instrumentation related to paste backfill production and transportation. The advantages to fluidisation technology are in reduced capital cost, reduced operating costs and in the environmental benefits of using full plant tailings over classified tailings or alluvial aggregates. Another major advantage is in the ability of this technology to be retrofitted to existing hydraulic backfill plants to further reduce capital cost. This paper details the development of the new technology as well as the associated cost savings over other technologies. It will also look at the research and development of unique components that make this technology work.

Jan 1, 1998

This paper describes the new iron and steelmaking process recently commissioned at NZ Steel. Ironsand mined and concentrated at Waikato North head is slurry pumped 18 km to the company's Glenbrook works. Ironmaking includes the direct reduction process pioneered at Glenbrook in the 1970s and a new continuous electric melter. The molten, high carbon pig iron produced is then fed to a vanadium recovery unit and on to the KOBM oxygen steelmaking vessel. Steel is cast into billets or slabs. The new plant, which is the first stage of a fully integrated works at Glenbrook, raises New Zealand Steel's production capacity from 150 000 t/y to 750 000 t/y.

Jan 1, 1986

By R Zhang, J Xu, X Lv, C Bai, S Zhang

This paper studies the grinding behaviour of vanadium-titanium magnetite concentrate in a ball mill. The grinding kinetics, surface morphology, lattice distortion, wettability and moisture capacity were analysed. Grinding kinetics equation was established based on population balances model with the size distribution data from a laser diffraction technique. The SEM photos of the ground concentrate showed that the surface gets rough with increasing grind time. Agglomeration of fine particles was enhanced when the grinding time reached 30 minutes. X-ray diffraction results showed that a loss in crystalline occurred with increasing the grinding time. The peaks of the X-ray diffraction patterns are significantly broadened with increasing grinding time. Wettability, characterised by contact angle between the material and water, improved due to the fact that the surface roughness increased with increasing grinding time. Moisture capacity of concentrate ascends abruptly in the first three minutes and then changed slowly with increasing grinding time. The water transfer coefficient in the particles increased rapidly in the first six minutes and then decreased quickly until grinding time reached 12 minutes.CITATION:Zhang, R, Lv, X, Bai, C, Xu, J and Zhang, S, 2013. Wet grinding of ?vanadium-titanium magnetite concentrate in a ball mill, in Proceedings Iron Ore 2013 , pp 511-518 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

Base metal skarns have provided most of South KoreaÆs Pb-Zn production since the end of the Korean War, with the bulk of production coming from the Yeonwha group of mines. Currently only the Kumho Zn-Pb mine remains in production, while magnetite skarns are mined as iron ore at the old Yomisan and Ulsan base metal deposits. Base metal skarns within Korea fall into two groups; those hosted in Cambro-Ordovician limestone sequences, situated mainly in sub-basins in the northeast of the peninsula and those hosted within carbonate volcaniclastics of the Cretaceous Gyeongsang Basin, in the southeast. Sulphide mineralisation is dominated by sphalerite, lesser galena, arsenopyrite and pyrrhotite, with subordinate chalcopyrite and molybdenite with Ag-Co credits. Skarns are composed of pyroxene-clinopyroxene-garnet-carbonate-quartz and magnetite, grading into silica-chlorite hornfels. Most of the significant deposits display both pipe-like and stratabound morphology. In the Hwanggang district, a zoned distribution of Ordovician carbonate hosted, polymetallic Mo-W and Zn-Pb-Cu-Ag base metal deposits is observed around the margin of a Cretaceous granite intrusion. Similar polymetallic zoning is recognised in the Sangdong district, where deposits include Sangdong (W), Abisan (Au-As) and Yomisan Northwest (Zn-Mo) and Yomisan Southeast (Zn-Cu-Co), hosted in Ordovician carbonates in proximity to Cretaceous quartz porphyry intrusives. The Taebaeksan district hosts the largest deposits at the Yeonwha group of mines. Although production ceased in 1993, significant resources remain, hosted in Ordovician limestone and dolomite that have been intruded by Cretaceous quartz porphyry dykes. Deposits in the Cretaceous Gyeongsang Basin consist of bedding concordant, vertically stacked base metal skarn mineralisation at several stratigraphic horizons, connected by carbonate-base metal veins with a pipe-like geometry. Evidence such as massive sulphide layers and restricted proximal carbonates suggest mineralisation was initially partly syn-depositional, with both base metals and carbonate venting onto a lake floor, being reconstituted to skarns by later magmatic activity. Skarn mineralisation is universally closely associated with the Cretaceous Bulgugsa Series acid intrusive activity. A common intrusive-structural relationship is recognised at some deposits, with bedding plane and imbricate thrust faulting, introducing felsic intrusives as sills. These intrusions probably introduced the base metals, carbonate, boron, heat and silica, which metasomatically reconstituted the carbonate lithologies to form skarn assemblages. The Korean base metal skarn deposits are regarded as Zn-Pb chimney-manto skarns and display similarities to the Mexican manto type deposits.

Jan 1, 1999

By Aguirre E, Chitombo G

The magnitude of stress variations associated with a blast wave near production pillars is analysed by modelling blast vibrations measured in the surrounding rockmass. The results indicate a wide variation in stress which is thought to contribute to the observed damage in pillars adjacent to the draw points.

Jan 1, 1995

By R M. Smart, A T. Harrison

Backfill systems using unconventional cementitious binders have been successfully used in relatively deep and hard rock tabular mines for longwall, scattered stoping and shaft pillar removals. Two unconventional cementitious systems are discussed: A ground granulated blast furnace slag (GGBS) with an activator containing lime. This has been used with a total tailings æstableÆ slurry at a relatively low dosage of less than seven per cent, by mass, based on dry solids. The room and pillar stopes supported with this fill were up to 20 m high and the tailings were relatively high in pyrite. A GGBS binder plus a silicate based activator and gelling agent that virtually eliminated all water drainage (and hence post filling shrinkage). The system used a slurry, but the addition of the activator created a final placed product that had the behaviour of a paste. The system has been successfully used for almost ten years in the following applications: stoping widths (mining heights) above 1.6 m; and shaft pillar removals in seismically active areas at the end of the life of the shafts. This paper discusses the technical merits and costs of the systems and compares them to other fill systems (including true paste systems). the acceleration (normally g, 9.81m/sec2) is increased to a significantly larger (but generally unmeasured and unknown) value, as shown in Figure 1.

Jan 1, 1998

By V Kumar, A S. Venkatesh, R K. Upadhya

The enormous iron ore deposits of eastern India are part of the volcano-sedimentary basins containing iron and to some extent manganese deposits that belong to the Iron Ore Group (IOG) of Archaean Singhbhum Craton, occurring as western and eastern limbs of a broad synclinorium. The eastern iron basin contains typically huge amounts of blue dust and powdery ores. There is a remarkable difference between the western flank ores and the eastern flank ores and the present study is part of the eastern flank ores from Noamundi. Demand for sintered fines as blast furnace feed coupled with the higher export price for lumpy ores that produce enormous amounts of fines during processing has created a situation whereby both primary and secondary fines, such as classifier fines, are being increasingly used as sintered feed for blast furnace. Systematic mineralogical and geochemical characterisation indicates that in many cases the ROM and classifier fines have to be processed to increase their Fe content and at the same time reduce their Al, Si and P contents. The fines which are already at micron sizes are amenable for beneficiation using the Mozley mineral separator and sink float test. It was observed that beneficiation was better and significantly greater by the sink float method than the Mozley mineral separator. Mineralogical and chemical studies of the fines reveal that around 80 per cent of alumina bearing minerals (gibbsite, clay and silicates) are present in the liberated form. Microscopic studies confirmed that the iron minerals are well liberated by controlled grinding to -300 mesh sizes with the beneficiation of iron ore fines and low-grade ores carried out using the Mozley mineral separator and sink float test. Beneficiation using the Mozley mineral separator increased the grade of concentrate with increasing flow rate of water as well as increase in amplitude of oscillation of the tray, but not very significantly with the increase in slope of the tray. In this method, though, iron concentration improved from 47 to 63 per cent with a recovery of around 67 per cent. It is not suitable for industry scale operation as only a small quantity of ores can be handled at a time. Beneficiation using the sink float test produced a better result with the Fe content increasing from 47 - 49 per cent to 66 - 68 per cent with a recovery of approximately 58 per cent. Initial feed Al2O3, SiO2 and Fe contents of 9.85 per cent, 15.3 per cent and 49.8 per cent respectively were beneficiated to 2.13 per cent Al2O3, 1.5 per cent SiO2 and 67.5 per cent Fe in the concentrate, with a recovery of 54.1 per cent. In contrast, using the Mozley table resulted in beneficiable contents 66.3 per cent Fe, 3.01 per cent alumina and 2.05 per cent silica. The combined alumina and silica content for the Mozley Table was >5 per cent, which exceeds the industry requirement of

Jan 1, 2005

Background A recent development in many industries,' including the mining industry, has been ever increasing acceptance and adoption of extended (12-hour) shifts and compressed work cycles compensated by more time off work by employees between cycles. In the Western Australian mining industry development of `long-distance-commute' (LDC) coincided with adoption of 12-hour rotating shifts. Preludes to LDC were the `construction-style' rosters with two crews plus allowance for annual and sick leave relievers working the statutory 13 consecutive shifts followed by one shift off. Crews rotated day to night shift weekly or at fortnightly intervals. Average hours of 72 to 78 per week were common. The author had personal experience working these rosters in the East Pilbara of Western Australia from 1977 to 1982. Workers tolerated these rosters until a suitable combination of frustration, boredom, despair and the `Five Grand Fever' triggered them to `pull the pin' and head for relaxation in Bangkok, Manila, Nimbin, or Margaret River according to their personal tastes.

Jan 1, 1996

By S N SHEARD

The use of geophysics in mineral exploration in Australia, and overseas, has increased dramatically over this century. This paper shows that using simple equipment with clever interpretation that the foundations of modem geophysics were laid, using all the same principles. The plethora and diversity of mineral exploration geophysical techniques does not allow a full description of their evolution to be given in such a paper. To convey this evolution, however, the progress of two different geophysical methods, magnetics - a potential field (passive) method, and electromagnetics - an electrical (active) method, are described. Examples of magnetic survey data from the 1920s and more recent vehicle home and airborne surveys are given to show the increase in data quality through technological improvement. A set of four airborne electromagnetic data sets spanning three decades is used to indicate the improvement in electromagnetic techniques. It is argued, that considerable progress is still required in the electromagnetic field to increase its interpretability.

Jan 1, 1992

By H Han, d S. Hapugoda, L Lu

With the recent rapid development of Chinese steel industry, the world iron ore resources of good quality are depleting rapidly. As a result, iron ore deposits of lower quality have been or are being developed to meet the market demand and are becoming increasingly important to iron and steel companies. As concentrates have advantages of high Fe grade and less harmful impurities, they are ideal sweeteners to maintain sinter grade and quality when high proportions of low-grade ores are used in the sinter blends. However, due to their fine nature, addition of concentrates will inevitably increase the proportion of adhering fines and reduced the proportion of nucleus particles of the sinter blends, which can adversely affect the green bed permeability and sintering productivity. In the present study, lab scale sintering tests were carried out under the conditions similar to the sintering process to examine the effect of concentrates on the high temperature sintering characteristics of sinter blends and the structure and strength of the resultant sinter analogues.

Sep 18, 2023

Increasing attention is being focussed worldwide on the strategic environmental assessment of mining projects, including consideration of cumulative environmental effects. In New Zealand there is now an end in sight for inappropriate delays in resource consent approval of responsible mining projects. This paper investigates six case examples of recently consented mining and quarrying projects, whose applications were notified. It also explores the nature of delays that occurred, the factors that contributed to the delays, and whether the consent process delivered fair and effective public participation and desirable environmental outcomes.

Jan 1, 2005

By K Sanematsu

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Ore deposits of rare earth elements (REE) in South-East Asia are classified into four types: carbonatite, allanite, ion-adsorption and placer. Occurrences of the carbonatite deposits are confined almost exclusively to the Red River Fault Zone of northern Vietnam. Since the carbonatites contain dominantly REE fluorocarbonates (eg bastnasite) and lesser amounts of monazite, they are rich in light REE but poor in heavy REE. The ion-adsorption type deposits and prospects were found in Myanmar, Vietnam and Thailand. The ion-adsorption ores generally show lower REE grades than those of the carbonatite type and placer deposits; however, they could be enriched in HREE, which are more precious and scarce commodities than LREE. The ores consist of weathered granites with a significant amount of ion-exchangeable REE, which are extracted by using a dilute electrolyte solution. The ion-exchangeable REE are likely to be sourced from REE fluorocarbonates, allanite and titanite because these minerals are relatively susceptible to weathering and release REE3+ ions into soil water. In contrast, monazite and xenotime are resistant to chemical weathering and could form placer ores. Placer monazite and xenotime have been processed as by-products of placer Sn, Zr or Ti in Malaysia, Thailand and Indonesia, although the current production is small.CITATION:Sanematsu, K, 2015. Rare earth element deposits and prospective areas in South-East Asia, in Proceedings PACRIM 2015 Congress, pp 671–678 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By A C. Robertson

Studies by Tennent, Isokangas Pty Ltd (TIP) have indicated that underground quarrying of backfill may be a cost competitive option for providing backfill for specialised situations in underground mining. Situations where suitable bulk fill material may not be available on the surface, and where the total cost of setting up a fill distribution system are prohibitive, could favour the mining of fill material underground adjacent to the stopes being mined. Considerations include environmental impact, scheduling, surface constraints and total costs. The examples quoted in this paper, and the case studies are based on the authorsÆ personal observations and experience.

Jan 1, 1998

By S Saydam

Professional engineers need to be able to apply university learning to practice. In particular, they have to take responsibility for interactions between technical systems and the complex social environments in which they operate. The most effective way of building this competency is through active experiential learning. We have been developing an advanced educational integrated simulation system to provide mining engineering students with an interactive and immersive learning experience that is not otherwise possible. This will give students an authentic experience in working with industry software packages, while also contextualising the learning in terms of the broader and longer-term impact of technical decisions. We have been piloting the system, in undergraduate courses in order to establish its effectiveness in building systems thinking competencies for mining engineering. For postgraduate students and professionals, the same tools and methods can support studies of more challenging and complex scenarios where mining engineers have to place their decisions within complex global industry contexts.

Nov 22, 2011

By Mutmansky J. M, Organiscak J, Qin J, Bhaskar R

The results of a two-year research study into the relationship between quartz dust levels in host material and in respirable dust in continuous mining sections are presented in this paper. The experimental design and sampling procedures for underground data collection are outlined. The sample analysis procedures for quartz determination, the analysis results and conclusions of the study are discussed.

Jan 1, 1988

By K Williams, G M. Evans, S M. Iveson, K P. Galvin, C E. Loo

The Australian Research Council (ARC) has recently established an Industrial Transformation Research Hub in the area of iron ore, focused on iron ore characterisation, beneficiation, materials handling and end-use functionality. The research hubs are part of a new initiative aimed at building stronger relationships between industry and universities, while addressing issues of national significance. The ARC Research Hub for Advanced Technologies for Australian Iron Ore will focus its attention on developing innovative approaches for creating enhanced value across the full value chain through the characterisation of different ore types, beneficiation and materials handling and transport. This hub brings together five industrial organisations and a research team formed from well-established research groups based at the Newcastle Institute for Energy and Resources. These groups have a record of working closely with industry to create opportunities. Examples include new beneficiation technologies such as the Reflux Classifier for achieving gravity separation, the expertise of TUNRA Bulk Solids in materials handling and the Iron Making Centre at Newcastle, which is a capability maintained by BHP Billiton following the closure of its Technology Centre in 2009. The purpose of this paper is to provide an outline of the research hub and its objectives, some background on the research groups that now form the hub and an insight into the strategy adopted for developing and implementing new technologies. The paper also describes a range of novel technologies that have the potential to be developed and applied to iron ore beneficiation.CITATION:Galvin, K P, Roberts, A, Loo, C E, Evans, G M, Williams, K and Iveson, S M, 2015. Australian Research Council research hub for advanced technologies for Australian iron ore – an introduction, in Proceedings Iron Ore 2015, pp 7–12 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By J Pan

In this paper, the technology of producing fluxed pellets by using hydrated lime as binder instead of bentonite was carried out. The properties of the two types green balls (0.8 per cent bentonite and 2.0 per cent hydrated lime) were as follows: drop numbers of 4.8 - 5.0 times/0.5 m, compressive strength of 19.7 - 24.2 N/pellet and thermal shock temperature of 280° - 385°, respectively, under the same conditions of 1.5 per cent coke, 1.45 basicity and balling at 8.5 per cent moisture for 13 min in disc pelletiser. Comparing with bentonite as binder, the compressive strength of fired pellets with hydrated lime is elevated by 13.8 per cent and climbs up to 3113 N/pellet under the following conditions: preheating at 1050°C for ten minutes and fi ring at 1300°C for 15 min. In the mean time, the hydrated lime also improves the metallurgical performance of fired pellets. The reduction index was enhanced from 68.6 - 70.6 per cent, RDI+3.15+ increased from 90.1 to 98.8 per cent and reduction swelling index dropped from 22.4 - 7.4 per cent, respectively. The mineral compositions and microstructure of fi red pellets shows that the fired pellets containing 2.0 per cent possess more calcium ferrite and magnesium ferrite and compact microstructure, leading to the higher compressive strength.

Jul 11, 2011

By D Elmo, M Scoble, Y Liu, B Klein, J Scholar, S Nadolski

A cave-to-mill study being conducted at the New Afton block caving operation demonstrated the potential for sensor-based ore sorting equipment to reject waste and improve the grade of feed to the mill. The lack of selectivity and potential for dilution entry associated with the block cave mining method results in many caving operations having to mine and process material that is below cut-off grade at certain stages of production. Online monitoring and bulk sorting systems have the potential to alleviate this problem and improve the productivity of caving operations while reducing energy and water requirements for each tonne of concentrate produced.As part of the cave-to-mill study, the suitability of a range of sensors, such as X-ray fluorescence and induction-type sensors, to sort mine production at the New Afton mine was investigated. Results showed that the discrimination of ore and waste can potentially be carried out by implementing surficial sensors into the material handling system. The study also showed that a combination of sensor outputs could be used to identify a certain ore type so that pre-emptive changes can be made in the mill to improve beneficiation performance. Overall, the outcomes of the study on implementing sensor systems at block cave mines are considered to be of significant relevance to a number of existing and future caving operations.CITATION:Nadolski, S, Klein, B, Elmo, D, Scoble, M, Liu, Y and Scholar, J, 2016. Investigation into the implementation of sensor-based ore sorting systems at a block caving operation, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 393–400 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

The Yanacocha district hosts the largest and most significant acid-sulphate, high-sulphidation deposits in Per· with total production, reserves and resources of over 27 million ounces of gold. Several other smaller high-sulphidation systems are also recognised in the Cajamarca region including La Zanja, Sipßn, Tantahuatay, and San Nicolas. These each have reserves/resources of between 640 000 and 800 000 ounces of gold. Gold deposits in the Yanacocha district are hosted in an extensive volcanic field. Flow domes have intruded precursor pyroclastic rocks and flows that are interpreted as part of an earlier intermediate multi-vent volcanic complex. The larger, contiguous Yanacocha Norte - Sur and Encajon gold deposits are spatially associated with late-stage diatreme breccias. At La Zanja extensive acid-sulphate alteration is associated with the margins of the small San Pedro caldera (6 +4.5 km), nested within the larger, less well-defined La Zanja caldera (19 +24 km). The inner caldera is resurgent with abundant magmatism expressed as several flow dome complexes located on the caldera rim, and shallow level intrusive stocks. Gold mineralisation is associated with a WNW-trending structural corridor that transects the southern margin of the San Pedro caldera. On the eastern side of the La Zanja caldera there are a series of younger andesitic eruptive centres, some associated with acid-sulphate alteration and gold mineralisation. The Sipßn deposit occurs in one such centre with structurally-controlled gold associated with a NE-trending silicified structure developed within a sequence of andesitic tuffs. In conclusion, although a number of high-sulphidation deposits are recognised in northern Per·, their settings and styles of mineralisation are all quite different. Smaller deposits generally have strong and obvious structural controls. In the larger Yanacocha deposits the structural controls are less obvious, and mineralisation is disseminated in porous or strongly fractured and brecciated silica. Erosional levels are probably a significant factor, with disseminated mineralisation at higher levels, and structurally-controlled mineralisation in more deeply eroded deposits.

Jan 1, 1999