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By Winrove G. S, Herdie G. J, McCarthy C. A

Production of hot metal from the Hlsmelt Research and Development Facility at Kwinana, Western Australia commenced in October 1993. The stand-alone facility is a unique, coal-based, integrated ironworks equipped to process iron ore fines to pig iron and simultaneously undertake a wide range of research tasks. The data generated will be used to verify the commercial potential of the technology and to set the design and operating parameters for a full-scale production plant. The design, construction, commissioning and initial operation of the HRDF has required many innovative and practical solutions to be developed and implemented by the international group of organisations contributing to the Hlsmelt Project. Initial operation has produced results which demonstrate the potential of the unique process technology associated with the core plant smelting unit. The recent achievement of post-combustion levels of 60 per cent with heat transfer efficiencies greater than 85 per cent demonstrates that the performance obtained with the Small Scale Pilot Plant in Maxhutte, Germany can be reproduced at a larger scale. The results presented in this paper support the thrust for further intensification and future commercialisation of the process.

Jan 1, 1995

The Circum-Pacific area is one of the most important gigantic skarn-metallogenic belts in the world. In more than 20 coastwise countries of this region, there exist thousands skarn deposits of different types. According to the differences of major metallic elements, the skarn deposits may be classified into seven subtypes, i.e. Fe, Cu, Pb-Zn, W, Sn, Mo and Au skarn deposits. In this paper, the distribution. and geological characteristics of above-mentioned types of skarn deposits are described briefly. Skarn deposits may also be classified on the basis of the dominant calc(magnesian)-silicate mineral assemblages into four types: magnesian, calcic, manganoan, and alkaline skarn types. Magnesian skarns may be associated with Fe, Cu, Au,, Sn, B, Be mineralization, calcic skarns with Fe, Cu, W, Mo, An, Be, Pb, Zn, Sn minerailization, while the alkaline skarns occur in U(Th, Nb) deposits. The skarn deposits of both East and West Pacific rims have many general characters, but have some diferences in geotectonic settings, intensities of mineralization, distribution, and metallogenic epoches. In this paper, the minerogenetic series and the mineralizing specialities of related magmatic rocks of the skarn deposits are also discussed.

Jan 1, 1990

China has abundant bauxite resources, but these resources are mostly of a diaspore, which has a feature of low Al2O3 to SiO2 mass ratio, typically ranging from four to six. Compared to other materials, this kind of raw materials consumes more alkaline and energy in the process of metallurgy, and incurred a high alumina production cost. To solve this problem, researchers in China have done a lot of work on removing of the silicon from bauxite. Under the impetus of these works, in 2003, the first flotation plant of diasporic bauxite in the world was constructed in Zhongzhou, Henan, China. Seven years of operating experience shows that this technology can signifi cantly reduce the costs of following-metallurgy processing. These efforts are an important reference for the processing of similar resource. In general, for Western scholars it is diffi cult to fully understand these works because most of them are published in Chinese. In this paper, a detail introduction for the research progress on China bauxite de-silica flotation was presented, these works involved crystal chemistry, wettability of bauxite minerals, collector and modifi er in bauxite fl otation and flotation practice, etc.

Sep 13, 2010

By Peng S. S

Measurement of pressure distribution under the base plate of the Hemscheidt 2-leg 800-ton shield was performed underground for two shifts using 12 pressure cells installed in two rows, one each under each split base plate. Pressure distribution was uneven depending on contact condition. In general the highest base pressure occurred at 1/3 of the base plate contact length from the rear edge. The resultant was near vertical, and the pressure under the tail side split base plate was always higher than the head side. For comparison, pressure distribution on the canopy and under the base plate was also measured under controlled conditions at the USBM's Mine Simulator Testing Facilities in Pittsburgh, PA. A total of 45 tests were conducted under several simulated contact conditions. The results showed that the actual contact area is highly dependent on the compliance of the immediate roof and floor due to the sloped canopy tip and a base lifting device under the base tip. The loading distribution tends to change in magnitude and profile as the leg pressure increases. The base lifting device exaggerates the high toe loading on the base plate characteristics of this type of shield support.

Jan 1, 1992

Thank you for your introduction and the opportunity to speak at such an important forum. I feel honoured to be the Tas McKee speaker for this yearÆs conference. I can honestly say that Tas McKee typified the spirit that has ensured the survival of the mining industry despite the modern-day challenges that we encounter. He was one of the most influential people in the New Zealand minerals industry. In 1938, with his father and brother, Tas established Lime & Marble Limited. Over its history, this company evolved from its original base of marble mining to diversify into gold mining and exploration for other industrial minerals, uranium, precious and base metals. He was truly a pioneer that persevered against the odds.   That leads me to the subject of my discussion today. I am going to delve into todayÆs challenges as they apply to gold companies. While we gold miners should be generating record returns, the gold industry shareholder return performance in this buoyant market has barely equalled that of the gold price. It is a dilemma but one that can be resolved with the right strategy.

Jan 1, 2006

The Waimumu area, 12 km southwest of Gore, is underlain by the Gore Lignite Measures, an early Tertiary fluvial sequence approximately 500 m thick resting on Triassic-Jurassic argillitic basement. The Waimumu Quartz Gravels (Pliocene) have been deposited locally and are in part due to the localised reworking of the Gore Lignite Measures. Structurally the area is dominated by the Dunsdale Fault System, a steeply dipping series of NE trending reverse faults (Isaac and Lindqvist, 1990). The Belle-Brook, Hedgehope and Parker Road sites sampled are adjacent to the downthrown (east) side of the Hedgehope Fault.The authigenic gold-sulphide association at Belle-Brook was discovered in 1987 (Falconer, 1987: Clough and Craw, 1989). Despite a very limited amount of alluvial mining a significant quantity of authigenic marcasite has developed. Authigenic sulphide trace element analysis has shown anomalous amounts of As, Ni, Cr and to a lesser extent Zn, Pb and eu (Table 1). It has been established that the nickel occurs as a colloform banded Ni sulphide, possibly bravoite, within the marcasite (Figures 1 & 2). Arsenic and nickel (re)mobilisation are well documented in the literature. Generally As and heavy metals are mobilised in the groundwater as a result of the oxidation of sulphides (ie as a result of mining). At Belle-Brook it is reasonable to assume the authigenic sulphide trace element composition reflects either localised groundwater contamination or hydrothermal mineralisation. This poster presents some preliminary findings.

Jan 1, 2001

COAL constitutes such a gigantic item in modern industry, either for direct heating, production of coke for smelting, or for the generation of power, that its quality and price play a very significant part in economic industrial progress. Australia is still a very young country industrially, and is groaning under many disabilities compared with competitors overseas, not the least of which is the quality of coal. Linked with the word "quality" should be that of "utility," for high-ash content prevents efficient utilization of the fuel.The marketing of good quality coal is a very important matter indeed, and if industry in Australia is to progress in the way that it should, this matter must receive keen attention.New South Wales, above all the other Australian States, has been blessed by nature with vast coal-fields, from which fuel is shipped to every State, and provides the base for power for most of our railroads and industries.Experts frequently refer to the fact that in some districts only partial extraction of thick seam coal is being made, without a care or thought for the future. Ranking next in importance to this is the fact that much of the coal is being carelessly marketed.Very few collieries in Australia are equipped with coal-washing plants for dealing more particularly with small coal grading which most industries require, and to which coal producers as a whole pay the least attention. In England each year nearly20,000,000 tons of coal is being water-washed before sale, and is marketed as a fuel of far greater utility once it has been freed from extraneous ash.Investigation proves that a great many pits in New South Wales are marketing coal (more particularly small coal) containing a considerable quantity of extraneous ash, due to the admixture...

Jan 1, 1926

By S Miller, R Smart, J Thomas

Single-addition and sequential net acid generation (NAG) experiments were carried out on natural and prepared samples with varying contents of organic matter and pyritic S. Results show that carbonaceous matter can produce significant quantities of organic acids during peroxide oxidation in the NAG test, which leads to overestimation of acid-forming capacity and misclassification of benign samples as potentially acid forming (PAF). Organic matter effects were most pronounced in samples with low S (less than 0.5 per cent) and total organic carbon (TOC) contents of greater than seven per cent. The single-addition NAG test will tend to overestimate acid potential in samples with little or no pyrite and high organic matter content, potentially leading to sample misclassification. High pyritic sulfur samples tend to show little difference in single-addition NAG acidities with increasing organic matter, and it appears that pyrite is preferentially oxidised by peroxide when present in significant concentrations (greater than one per cent pyritic S). In sequential NAG tests overestimation was greatest in samples with little or no pyrite, but highly carbonaceous (>20 per cent TOC) pyritic samples were affected in later stages as the pyrite was depleted. A modified NAG method is proposed to account for the relative proportions of pyrite derived acidity and organic acidity in a given NAG solution.

Jan 1, 2003

In 1997, the Australian coal industry through Standards Australia committee MN-001 Coal and Coke recognised the need to produce a Standard giving some instruction on how to inspect and audit mechanical sampling systems. A Guide was developed by sampling subcommittee MN-001-04 and in 1999 the Standard was released as AS4264.5 æGuide to the Inspection of mechanical sampling systemsÆ Coal and Coke. Since that time the author has assisted with other committees in developing the Guide for other commodities such as concentrates and a generic standard for particulate materials. (AS4433.6 released 2000). The Coal and Coke guide is also currently a work item for ISO Standards. This paper is focused primarily on auditing and inspection procedures for coal mechanical sampling systems. It highlights the need for at least a three level inspection protocol where the operators manning the system maintain operational checks, the operators are regularly supervised by the company managing the system and once per year an independent auditor inspects the whole system to ensure compliance with design and standards. It does not cover short- and long-term maintenance of individual systems. With companies already certified to the ISO9000 series, this guide forms the framework to bring the operation and inspection of their mechanical sampling systems into line with these principles.

Jan 1, 2005

It is often said in business that if you donÆt have a customer you donÆt have a business. The same rule applies to project evaluation; if you donÆt have customers you really donÆt have a viable project. It is therefore essential that in the early stages of project evaluation the following fundamental questions are addressed: What products will this project produce? Who are the potential customers? What are the customersÆ requirements with respect to grade and impurities? Do they have adequate capacity to take the production from the proposed project? Will the products introduce adverse effects in the customerÆs process circuits? Will additional waste streams requiring disposal be produced? In the past the attitude has been along the lines of the customer will take whatever we produce at the mine site. Times have now changed with customers now operating under much tighter environmental regulation with waste disposal becoming increasingly difficult. It would therefore be prudent that the principles of product stewardship be used as a tool in project evaluation. This paper will provide a general discussion on customer requirements and provide detail on case studies of the impact of mine products on smelter process circuits. It will provide examples where there were synergies between the mine product and the smelter circuit and where the mine product had adverse impacts on smelter performance.

Jan 1, 2007

The classical view of island arc geology is that of a plutonic intrusive/volcanic extrusive complex, derived from the products of oceanic lithosphere subdu.ction and constructed on an over-riding plate of oceanic origin. Such an arc is typically backed by a marginal basin, formed by seafloor spreading of a more or less conventional kind. Various studies undertaken over the last decade have modified this picture and provided a new tectonic framework within which to explore for resources. Formation of Marginal Basins During the 1970s, seafloor spreading magnetic anomalies were identified in various marginal basins in the SW Pacific. In one of these, the South Fiji Basin, there was clear evidence of a ridge-ridge-ridge triple junction, although no kinematic relationship to the major plate boundaries was determined. Palaeomagnetic studies conducted in Vanuatu and Fiji, and in the Bismarck Archipelago of PNG provided evidence of large scale arc rotations relative to major plates. This indicated a general pattern of marginal basin formation by ridge-ridge-ridge triple junction growth together with island arc growth by trench-ridge-trench triple junction evolution. Formation of Primitive Island Arcs The triple junction growth model strongly suggests that at least a significant amount of arc evolution occurs by the initiation of subduction at a spreading ridge. This has predictive implications for the nature of island arc basement.

Jan 1, 1987

The type of population encountered in the sampling of coal, ores and other products of natural phenomena is one in which the variance within a cluster of elements generally increases steadily as the size of the cluster increases. To enable estimation of variances of stratified random or systematic sampling for such populations one must model the serial correlation function or alternatively, the variogram function. The author has postulated a specific symmetry of the serial correlation function which leads to expressions with rich theoretical and practical implications. These expressions provide a spatial correlation function which explains power law relationships often observed in studies of dispersion variances. They also enable straightforward calculations of sampling variances. The importance of the role of finite population size in the equations leads one to examine previously held concepts of ælargeÆ and æsmallÆ sample populations. The model based on the symmetry postulate is a fractal model with the serial correlation function of a hypothetically infinite population being of the same form as that developed by Mandelbrot for discrete fractional noise. Techniques used in fractal mathematics apply, including box counting and fitting of a dimension function. The paper establishes a framework for the understanding of this fractal theory and demonstrates how to calculate sampling variances from the model variogram using simulated data fitting the model.

Jan 1, 2008

By J Herbertson

æZero waste steel making productionÆ has already been the subject of several studies and also the successful result of some companies. Regarding waste and by-products, slags are the largest in terms of weight, although among the least hazardous. All steelmakers around the world are presently looking into profitable solutions, according to their local conditions: environment constraints, available markets, and mode of operation. Today the major technical methods of slag value capture include different levels of magnetic separation and screening to remove entrained steel, for production of aggregate in civil works. A survey of different retrieval processes shows that pyrometallurgical processing of steelmaking slags will increase the recovery ratio of iron and other metals. In the process, the remaining part of the material, a mixture of metallic oxides, can be easily transformed into hydraulic binder such as cement. Can steelmakers consider the slag as a co-product, and not only a waste or by-product? The ability of pyrometallurgical processes to treat other wastes and by-products generated in the steelplant is an opportunity for the steelmakers to reach the æzero waste productionÆ status. A technical survey of the experiences and possible solutions of pyrometallurgical processing is presented as well as technical descriptions of technological, economical and profitability analysis in relation with foreseeable markets.

Jan 1, 2002

Mining projects draw together stakeholders with various degrees of experience in managing and assessing financial risk. When this risk is not fully appreciated or quantified, the potential for making decisions not suited to investor requirements is significantly increased. A feasibility study provides key information on project development potential, requiring detailed technical investigations with thorough financial analysis. Centaur Mining and Exploration (CME) owned and operated Cawse Nickel Operations (CNO), one of three Australian projects to develop and process vast amounts of near surface nickel resources. A technical ædue-diligenceÆ and æbankable feasibility studyÆ confirmed the large resource base, newly applied yet tested technology and relatively low unit costs would produce nickel in the lower half of industry operating costs. A number of production variables including capital requirements, delayed start-up, nickel grade, processing, maintenance and product output were outside the feasibility estimate. This was combined with exchange rate fluctuations and lower Ni prices. The inability to generate adequate cash flow and service debt repayments ultimately led to receivership and liquidation of all assets. Following the sale of CentaurÆs gold and nickel divisions, $A 784 million remained outstanding to creditors. This paper aims to define key issues leading to CNOÆs collapse by reviewing feasibility parameters, valuation methodology and project development. Some methods of assessing project viability are discussed with the aim of increasing stakeholder risk awareness.

Jan 1, 2003

By Eggleton R. A

X-ray diffraction techniques are commonly used in the identification and quantification of fine-grained materials. A relationship exists between the size of crystals in a sample and the degree to which they diffract X-rays. The Scherrer equation relates the broadness of diffraction peaks to the size of crystals responsible for diffraction (Klug and Alexander, 1974). Relatively large crystals of the order of I - 10 ¦m strongly diffract X-rays; the diffractogram of such crystals exhibit narrow intense peaks. As the size of the crystals in a sample is reduced, diffraction peaks become broader and less intense. Crystals less than 10 nm generally exhibit broad, diffuse and low intensity peaks. Some material is so fine-grained and poorly-diffracting that X-ray patterns show very little information in a normal one-hour scan thereby necessitating very long acquisition times of up to 12 hours. The term poorly-diffracting material (PDM) was coined for such material found within the bauxite deposit of Weipa, northern Queensland (Tilley and Eggleton, 1994; 1996). Common regolith minerals such as hematite, goethite and layer silicate clays are quite commonly fine enough to possess a poorly-diffracting character. Noncrystalline and poorly crystalline Fe-Si-Al-oxyhydroxides such as allophane, opal, ferrihydrite and hisingerite, have either a nondiffracting (amorphous) or poorly-diffracting nature (Eggleton, 1987).

Jan 1, 1997

In recent years a large amount of work has been done at various plants overseas, and also at Broken Hill Associated Smelters, Port Pirie, South Australia, on the use of Dwight Lloyd sintering plant gases for sulphuric acid manufacture by the contact process.Several plants have modified their sintering machines and operating procedure, and some have adopted gas recirculation techniques, to obtain a relatively high proportion of the sintering plant gas at an S02 concentration acceptable to a contact acid plant 1.These adaptations were investigated at Port Pirie, and it was found that gases of suitable S02 concentration could be obtained. The results justified installation of a contact acid plant and a decision was accordingly made in 1949 to construct such a plant.However, the local conditions presented some difficulties not generally encountered at other plants, the chief differences being:a. For maintenance of production of 98% H2S04 , an unusually high S02 concentration is required, because of the prevailing high temperature 'of the purification train cooling water.b. The entire sintering operation is conducted on two large machines, 55ft. x 10ft., operating in series as "First" and "Second over" machines (a two-pass roast.) Any interruption" to either machine causes a complete interruption of plant operation and gas flow.

Jan 1, 1951

Rock formation at shallow depths is generally associated with complex geology consisting of many joints, fractures, bedding planes, etc. Fragmentation results from primary blasts in such strata are therefore significantly influenced by structural discontinuities. To evaluate the role of discontinuities, which is of great use in the design of blasts in such conditions, a two-stage investigation program was taken up. In the first stage, model scale tests were conducted with single and double holes with the strike of discontinuities parallel and perpendicular to the face. Later, field studies were conducted in a limestone mine and a coal mine. Blast patterns were modified based on the results obtained from model scale blasts. Secondary blasting was taken as a measure to assess blast performance in the field, whereas mean fragment size, fine and coarse fragmentation indices were considered as fragmentation measures in model scale tests. Model tests indicated confinement of explosive energy by the discontinuities surrounding blasthole. Crater shape and size were significantly influenced by the orientation of joints with respect to the face. Modified blast designs with decreased burden x spacing patterns resulted in improved fragmentation in the field. A reduction of about 12 per cent in explosive consumption was recorded with modified blast designs. Boulder formation was observed to decrease by about 79 per cent as well.

Jan 1, 1995

The Manto Verde copper mine (Atacama Region, Chile) is due to go into production in 1996. It will produce 40 000 tonne/year of copper cathode by heap leaching/SX-EW. Mineralogical studies were undertaken in conjunction with the metallurgical testwork program to characterise the ore and its response to leaching by dilute sulphuric acid. The leachable copper mineralogy is dominated by the oxide copper minerals: brochantite and malachite with minor chrysocolla and atacamite. The gangue minerals include abundant orthoclase, specularite, quartz and chlorite with minor muscovite and trace smectite clay, calcite and limonite. The study showed that complete or partial decomposition of calcite, chlorite, smectite and wad consumed acid and generated solution impurities (Ca2+, Fe2+, Mg2+, A13+, K+, Si4+ and Mn4+2+ ). Although these were manageable at Manto Verde, their uncontrolled build-up could have affected the operation in several ways: the degradation of heap penneability and fonnation of crud in the SX plant from the precipitation of gypsum, goethite, colloidal silica and jarosite; and the entrainment of contaminated pregnant leach solution in the SX organic resulting in the transfer of impurities to the electrolyte and subsequent effects on cathode quality and electrowinning efficiency. In conclusion, process mineralogy played an important role in understanding and managing potential mineral-related problems in the heap leaching and SX-EW recovery of Manto Verde ore.

Jan 1, 1994

The Drake-Rivertree area lies in the far north east of the New England district of New South Wales. Drake is some 500 miles north of Sydney by road and 36 miles west of Lismore. Rivertree is situated 24 miles north of Drake.The Drake deposits were first worked in 1878 for gold which occurred in a very fine state in ferruginous gossan but at depth copper ore became more significant. The lodes at Rivertree, discovered in 1887, were worked for silver but mixed sulphides became more prominent in deeper levels.Several mines operated at each centre and each locality smelted its own ore.The mines at both centres were operated sporadically for many years though production was not particularly substantial.A number of the larger mining companies have shown a recent interest in this mining field with special emphasis on the Drake locality.GENERAL GEOLOGYThe two mining centres are situated to the north and south respectively of a belt of Permian marine sediments and volcanics similar to, and probably representing an easterly extension of, the rocks of the Emmaville district further west.E. C. Andrews (1907) recognized two stratigraphic units within what he called the Drake Series. The Lower Division consists of rhyolite flows, tuft's, breccias and agglomerates, followed by trachytic and andesitic tuft's containing cladochonns, thanmopora willcinsoni and other Permian forms.

Jan 1, 1962

By S Hapugoda, J R. Manuel, M J. Peterson

Microindentation testing using the square–pyramid–shaped Vickers indenter is a well-established technique to determine the microhardness of minerals and materials. However there is a paucity of published microhardness data from Fe ore samples. It is acknowledged that an iron ore’s particle mineralogy and texture is critical to its processing properties, and it is therefore considered that the microhardness of different mineralogical/textural types may also relate to these properties. Mineral microhardness potentially provides inputs to the modelling of breakage characteristics during comminution, as well as the relationship between mineral chemistry and microhardness, and mineral microporosity and microhardness. Microhardness can be determined as single crystal microhardness, for more coarsely microcrystalline samples, or as ‘aggregate microhardness’ for cryptocrystalline or finely microcrystalline samples.Variations in the texture and mineral chemistry of common Fe ore minerals (eg martite and microplaty hematite, ochreous and vitreous goethite etc) are well established and this study provides microhardness data on different textural forms of Fe (oxyhydr)oxides from a variety of different Fe ore deposits. The data indicated that in general, the mineral grain size, microporosity and texture were the main influences on Fe (oxyhydr)oxide microhardness. There were no apparent systematic variations between microhardness and minor element mineral chemistry, with the possible exception of Al content in goethite (for goethites with Al content >0.5 wt per cent), and for goethite total element contents >90 wt per cent (determined by electron probe microanalysis, EPMA). Higher Al concentrations and lower total element concentrations in goethite EPMA analyses correlated with lower goethite microhardness. Microporosity and grain size were more important than texture to hematite microhardness. Different textural forms of dense hematite (eg martite, recrystallised interlocking hematite and specular hematite) with similar grain size exhibited comparable microhardness. Microhardness values for hematite and hydrohematite with little or no evident microporosity were also similar, whereas more porous forms of martite, microplaty hematite or hydrohematite exhibited lower microhardness.CITATION:Peterson, M J, Manuel, J R and Hapugoda, S, 2017. Microhardness testing of hematite-goethite Fe ores – implications for their textural characterisation and geometallurgy, in Proceedings Iron Ore 2017, pp 319–330 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017