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By R C. Morris

Secondary microplaty haematite in its variety of styles and generations is the defining component of the high-grade banded iron-formation (BIF)-hosted iron ores of the world that are dominated by martite (M; - haematite pseudomorphs after magnetite). The term microplaty haematite (mplH) was introduced during the CSIRO-AMIRA 1976-1994 iron ore program, and was used to differentiate the then main export martite-microplaty haematite (M-mpl H) ore types of Tom Price-Whaleback and Paraburdoo (Paleoproterozoic), from the newly exploited, more prolific supergene martite-goethite (M-G) ores (Mesozoic-Paleocene) of the Hamersley Province that are now the major Hamersley iron ore exports.Morris (1980, 1985) suggested that the most important genetic factor that distinguishes the two main ore types was regional metamorphism of Paleoproterozoic M-G ores at temperatures normally related to diagenesis (ca 80 - 100°C). As temperatures increased, mplH grew in goethite both spontaneously as well as by nucleating on martite and other pre-existing haematite. Because the conversion of goethite to haematite involves a ~27 per cent reduction in volume, the crystals probably grew within microvoids of their own creation, with iron transfer through water resulting from the process itself, a local hydrothermal process requiring no introduced hypogene fluids.Barley et al (1999) and Taylor et al (2001) concluded instead that oxidation of introduced siderite in hydrothermally metasomatised BIF ‘protore’ resulted in mplH + ankerite by reaction with heated meteoric fl uids. This postulated ‘protore’, still preserved locally at Mt Tom Price, was described during the CSIRO-AMIRA program as local post-ore BIF metasomatic residuals. These new hypogene-meteoric concepts for M-mpl H genesis have formed the basis for a range of varying local and international models that currently dominate the literature of iron ore.No valid petrographic data supporting the hypogene-supergene modelling was found but petrographic images of goethite-related mplH growth in a range of different environments are shown.

Jul 11, 2011

The value derived by good mine planning is often underestimated as many mines steer their attention to the more immediate and more easily recognised successes made by the day-to-day operational æbush fireÆ fighting. Similar to machine maintenance, the efforts made to quickly rectify short-term breakdowns are well recognised; whereas the value derived from the work in planning, scheduling and undertaking preventative maintenance is not so obvious or readily quantified. Too often the focus of the business shifts to building and supporting an efficient operations team at the expense of developing a highly experienced team of mine planning practitioners that are well trained with procedures and purpose-built tools to develop optimum mining strategies. A resource has an inherent value based on its quality parameters and its likely mining conditions. How well that value can be unlocked is governed, to a large degree, by the proficiency of the mine planning practitioners, as they, essentially, set the foundation of the mine business and the path along which the mine will operate. The importance of having a well documented and procedural mine planning methodology that integrates both a thorough technical and economic understanding of the resource cannot be over emphasised. The aim of the mine planning process is to develop a robust mine design and production capability which can best cater for future uncertainty whilst providing the best opportunity to maximise cash flow into the business. The planning process must be transparent and auditable, clearly summarising the process steps and assumptions made to arrive at a justifiable and defendable outcome. To provide maximum value to the business, the planning process must be repeatable and scalable to enable easy replication throughout the different mines and projects within an organisation. The diminishing numbers of highly experienced personnel within our industry, coupled with the growing pressure to clearly demonstrate that appropriate due diligence has been exercised, means that well documented and monitored mine planning processes using purposed built and innovative tools need to be developed to ensure optimum outcomes.

Jan 1, 2009

By D La Rosa, G Power, K Riihioja

In underground mining, the often unpredictable variability in ground conditions may lead to the application of suboptimal drilling and blasting patterns, resulting in poor performance. Experience and pertinent information to develop and implement improved drilling and blasting strategies can be easily lost due to the lack of means to help engineers store, access and manage this information. The Julius Kruttschnitt Mineral Research Centre (JKMRC) through a series of industry funded applied research projects has been developing a system that can facilitate the drill and blast design, analysis, auditing, documentation and data management processes. The system is a hybrid between an information management software module called BMS (Blast Management System) and two design and analysis modules, 2DRing for underground production blasting activities and 2DFace for development blasting activities. A concise description of the software tools and its applications are given in this paper, supported by two case studies. Opportunities to further develop the software are also highlighted, they include options to integrate these tools to existing drilling and blasting automation systems and portable computing technology to facilitate the design, implementation and continuous improvement processes.

Jan 1, 2001

By K Orth

The volcanic successions that host massive sulphide deposits are diverse in composition, facies types and facies relationships. They also show a variety of spatial and temporal relationships to mineralisation. In many examples, such as the Koongie Park Formation in Western Australia, the host succession includes more or less conformable syn-volcanic sills with peperitic contacts. Such sills can be an important source of heat for fluid circulation, influencing patterns of hydrothermal alteration and the location of co-eval and later mineralisation. The impact of syn-volcanic sills on the host succession depends in part on the initial porosity and permeability of the enclosing facies. The special properties of glassy pumice û being highly porous, permeable, and reactive û allow pumice-rich facies to preferentially focus hydrothermal fluid flow. However, the same properties promote early alteration and porosity reduction. Hence, the diagenetic and compaction history of pumiceous facies strongly influences their potential to host massive sulphide mineralisation. In contrast to pumice, dense glass has relatively low porosity, at least initially, and does not compact. Non-vesicular glass is a major component of submarine lavas, syn-volcanic intrusions and some volcaniclastic facies. However, especially in submarine settings, dense glass is commonly intensely perlitically fractured soon after eruption. The fractures greatly increase the porosity and permeability, locally accelerating diagenetic and hydrothermal alteration. In addition to false pyroclastic textures, altered perlite may exhibit false porphyritic textures. Silica- or feldspar-altered perlite kernels surrounded by intensely altered phyllosilicate domains can resemble phenocrysts in a fine grained groundmass.

Jan 1, 1999

By Smart RST C, Johnson NW, Ralston J, Griffin LF

At the Copper Concentrator of Mount Isa Mines, the largest diluent of the copper concentrate is liberated fine pyrite. Laboratory flotation tests carried out as a function of grind and flotation Eh in combination with surface analysis by X-ray photoelectron spectroscopy (XPS) have identified the major mechanisms of iron sulphide flotation. It was found that a significant proportion of the iron sulphide minerals had surface coverages of graphitic carbon, sufficient to impart moderate hydrophobicity in the absence of collector. A smaller, but economically significant proportion of chalcopyrite was also affected by the graphitic carbon coating. Two methods were tested to reduce the impact of the natural floatability of the iron sulphides on concentrate grades. 1. Depression through the use of organic depressants. 2. Preflotation to remove the "naturally hydrophobic" iron sulphides (flotation independant of Eh ) prior to chalcopyrite flotation. Preflotation was tested at the pilot plant scale. It was found that the amount of chalcopyrite reporting to the preflotation rougher concentrate could be minimised through flotation at a mildly reducing Eh by the use of nitrogen as the flotation gas to maintain the low Eh conditions resulting from grinding. The preflotation rougher concentrate was upgraded to an iron sulphide concentrate or a low grade copper concentrate.

Jan 1, 1991

By K Koskinen, S Ronkainen

The flow field induced in an Outokumpu TankCell and by an OK rotor-stator mixing device in a laboratory and a process size flotation cell was modelled numerically using computational fluid dynamics (CFD). The primary target was to discover and reproduce the various interactions between the flow field and the flotation cell by numerical means. As power consumption depends sensitively on flow field, it can be regarded as a top-level derived quantity (or measure/metric) indicating the validity of the numerically obtained flow field. Having properly validated numerical means to produce the flow field the influence of various design parameters can be captured with certain accuracy. In addition, separate gas and solid phase models for bubbles and solids, respectively, were implemented. The comparisons between velocities and turbulence quantities measured using the laser doppler velocimetry (LDV) technique and CFD modelling were performed. The grid generation was performed with the commercial Gambit 1.3 and the subsequent integration and solving of the resulting algebraic equations with the commercial CFD-code Fluent 6.22. The computationally economic multiple reference frame method was included to model the moving rotor blades. Gas and solid phase models were modified mixture models.

Jan 1, 2005

By M Griffiths

This paper outlines an approach to high solids slurry pipeline design with data generated from a closed pipe-loop test system. The pressure and flow rate data generated is used to develop a pseudo-shear diagram for the purposes of system design. Following this approach enables the design of a full pipe flow system maximising system life and reliability. The alternative free fall system is explained and the disadvantages highlighted.Environmental and social considerations are discussed; mainly water and land use, and how designing for high solids slurry pipeline systems can be used improve these aspects of a mining project.Also discussed is how the use of high solids slurry pipeline systems can help to mitigate the risk associated with surface tailings storage facility failure, with the Bulyanhulu project used as a positive example.

Aug 8, 2011

By B Y. Luan, Y Tian, W Zhou, X Lu, Q X. Cai

The unmanned driving technology in open pit coalmines is an important technology that relies on innovation to drive the development of the open pit coal mining industry in China’s transformation of growth drivers and industrial structure upgrading. It is an important path to solve the shortage of mine truck drivers in the future mining, an important way to improve the working environment of open pit mining personnel, and an important foundation for achieving flexible production capacity in open pit mining to cooperate with the coordinated development of new energy. The communication rules at intersections are key to ensuring the safety and efficiency of unmanned driving in open pit coalmines. This paper proposes a collaborative traffic strategy between unmanned trucks for the single bucket unmanned truck intermittent process system in open pit coalmines. Based on the gap theory, this paper analyses the conflict characteristics and establishes a coordinated traffic strategy for the common intersection and merging conflicts of unmanned truck trucks in open pit coalmines, A multi-agent system simulation platform was built to evaluate the coordinated traffic efficiency under different initial average gap sizes of vehicles, with intersection traffic density, vehicle speed, and gap changes as key indicators. The results show that under the simulation conditions of this article, when the initial average gap of vehicles reaches three (four) times or more of the safe distance, the coordinated traffic performance of intersection conflicts (merging conflicts) is better, and the traffic capacity of intersections is close to the traffic capacity without conflicts.

Sep 1, 2024

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

By T Kon, K Ohno

Slag foaming is an important control item in the process of refining molten steel. This study aims to investigate the factors controlling slag foaming by observing the bubble formation behaviour resulting from the chemical reaction between iron oxide and Fe-C alloy in the slag. In this study, 0.06 g of Fe- C alloy was introduced at the bottom of a BN crucible, and 6.0 g of slag (SiO2:CaO:Fe2O3 = 40:40:30) was placed on top of it. The crucible was positioned inside an infrared image heating furnace, where the temperature was rapidly raised to 1370°C at a rate of 1000°C/min in a nitrogen stream, and then held at that temperature for a predetermined time before rapid cooling. Following rapid cooling, the internal structure of the sample was examined using a high-resolution X-ray CT device. The spherical equivalent volume was calculated based on the number of observed bubbles and their equivalent circle diameter. Additionally, the relationship between the volume ratio of small bubbles in the slag volume and the distance from the bottom of the crucible was determined, along with the calculation of bubble density and volume ratio. Under various experimental conditions, numerous bubbles with equivalent circular diameters ranging from 200 to 300 μm were consistently observed. The density and volume fraction of bubbles with circular equivalent diameters between 200 and 500 μm showed a tendency to increase as the distance from the bottom of the crucible increased. Bubbles with equivalent circular diameters of 500 μm or more consistently exhibited lower bubble densities, regardless of their height within the crucible. The formation of larger bubbles is attributed to a decrease in iron oxide concentration within the slag as the reaction progresses. However, this is believed to be due to their higher buoyancy, resulting in shorter residence times within the slag and a reduction in the number of encapsulated bubbles.

Aug 21, 2024

By N Setoudeh, A Nosrati, N J. Welham

The current surge of interest in lithium (Li) is due to the anticipated demand for electric vehicles and small scale power storage. Brine deposits contain most of the global Li resource, however hard rock deposits can be more readily and rapidly developed and comprise the majority of proposed projects. These projects plan to use the conventional processing routes of dense medium separation and / or flotation to produce a spodumene concentrate for sale. The standard route for subsequent processing of spodumene concentrate is thermal decrepitation, acid leaching, solution purification and precipitation of lithium carbonate. This is typically followed by further purification. A number of projects have ores which contain other lithium minerals, principally micas, lepidolite and zinnwaldite, necessitating an alternative treatment route. Several different routes for spodumene processing are under development to reduce costs to compete with brine projects. This paper will give an overview of the strengths and weaknesses of the current and alternative processes.CITATION:Welham, N J, Nosrati, A and Setoudeh, N, 2017. Lithium ore processing – an overview of the current and new processes, in Proceedings MetPlant 2017, pp 185–194 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

The New South Wales Department of Mineral Resources has, since 1974, administered the Derelict Mines Rehabilitation Program (DMRP) to reduce the environmental impacts of abandoned and orphan mine sites. The application of the DMRP is presented in case studies of sites from the South Maitland Coalfield featuring residual drainage of acidic and saline water in a semi urban and rural community setting. The acidity here is typically derived from iron oxidation in shallow underground coal mine workings and in surface emplacements of coal washery reject materials. This paper presents summary information on AMD investigation, monitoring and rehabilitation. The experiences of community expectation, stakeholder consultation and peer review are discussed.

Jan 1, 2003

This paper deals with the extension of Post Office telecommunications (telephone, data, leased private lines etc.) network to mining communities in remote areas of Australia. The evolution of the "Spur Line" policy and its application is referred to together with comments on the engineering of telecommunication Facilities.

Jan 1, 1973

By Happ J. V

Factors affecting the rate of arsenic removal from lead bullion during softening processes were studied. Very high rates of removal could be obtained under conditions of intense agitation and ready availability of oxidant. Reaction mechanisms were proposed to explain the sequences observed. Selective removal of arsenic with minimal loss of antimony from bullion was favoured by a low temperature Harris process and oxidizing via a caustic soda medium.

Jan 1, 1987

By Hammett PHJ

Oil Exploration Companies are primarily interested in how much oil or gas is present in the rocks in an area in which an exploratory well is drilled. The solution of this problem requires a combined effort on the part of the petroleum geologists, drilling engineers, logging and drilling contractors. To help in'explaining how the drilling and evaluation is earried out the paper has been divided into two sertions, one titled Drilling which is presented by Mr. P.H.J.-Hammett and the seeond titled Evaluation which is presented by Mr. R.M.L. Elliott. A typical Perth Basin Well has been chosen as art example for this presentation. In Figure 1A is shown the type of sandstone and shale sequence encountered in this area.

Jan 1, 1964

By Gang L

Seventy-nine gold deposits and prospects have been discoveried in the Jiamusi region of northeast China, and constitute one of the most important gold metallogenic belts in China. All these endogenic gold occurrences can be subdivided into three main deposit types: (1) porphyry related; (2) metamorphic-intrusive hosted, and (3) sediment-hosted deposit. The first two types of gold deposit are spatially and temporally related to Mesozoic Yanshanian granitoid intrusions with hydrothermal activity channelled along crustal-scale fissures. The ultimate cause of the Yanshanian magmatism is considered to be the subduction of Pacific oceanic lithosphere beneath the Eurasian continent. In contrast, The chemical sediment-hosted deposit is typified by the Dongfengshan gold deposit, and genetically related to Proterozoic sedimentation and Mesozoic igneous activities.

Jan 1, 1995

By Li T

Mining of the southern 1900 copper Orebody presented a challenge due to the complex geology, geometry and simultaneous extraction of the nearby lead/zinc/silver orebody. An integrated and co-operative approach was adopted, involving geology, geomechanics, mine planning and production personnel. Successful extraction of the first 1900 Orebody stope, T496, together with the extraction of the first two lead/zinc/silver panel stopes in the immediate hangingwall of the 1900 Orebody stope was achieved as a result of this approach.

Jan 1, 1995

By K E. Barns, P J. Sharman, S A. Thomas and

This paper presents the development of a regrind facility design at BHP BillitonÆs Leinster Nickel Operations (LNO) in Western Australia. The recovery opportunity was identified from an analysis of plant operating data together with scanning electron microscope (SEM) measurements on relevant tailings streams from LNO. A laboratory procedure was developed to determine the potential recovery improvement of installing a regrind facility at LNO. The last step in formulating the process flow sheet and defining the process design criteria was to construct and operate a pilot plant, which incorporated four banks of flotation cells and an Xstrata M20 Isa Mill. Pilot plant on/off trials were used to define the expected metallurgical benefit. A prefeasibility engineering design and cost estimate was completed. Following a successful internal business evaluation, a feasibility study is currently underway.

Jan 1, 2007

Gallium occurs at above background levels in most samples collected from 11 of the major geothermal areas in the Taupo Volcanic Zone. Concentrations of Ga in the 48 samples ranged from 8 to 144 mg kg-1 and varies widely from place to place within each geothermal area. Gallium is contained within the alumino-silicate structure of clay in the mud, having substituted mainly for Al. Suggested deposition mechanisms for Ga also involve co-precipitation with Sb, As, and SiO2 colloids. Digestion trials, carried out to determine extraction conditions for possible commercial exploitation, showed that heating the mud to 500 - 600¦C for 1 hour followed by acid/alkali treatment gave complete recoveries.

Jan 1, 1995

By Singer RP

The Latrobe Valley brown coal deposits are one of Australia's major energy resources with measured and indicated reserves amounting to some 162 billion tonnes. Economically recoverable reserves are estimated at some 65 billion tonnes, 47 billion tonnes of which are classified as available for mining (VBCC (1983)). These deposits contain one of the lowest grade fuels used anywhere in the world. Typical Net Wet Specific Energy values range from 6 to 9 MJ/kg. Despite the low energy value of the raw coal, the Latrobe Valley deposits represent approximately 90% of Victoria's indigenous non-renewable energy resources. Utilisation of this vast primary energy resource has been a key factor in the economic development of Victoria.

Jan 1, 1990