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By R. Flatabø, K-E. Johansen, L. Hunsbedt, P. M. Cowx, J. A. Bustnes

Eramet and Tinfos are two producers of manganese alloys in Norway, which have worked hard for several decades to improve both the internal and external environment. Furnaces producing ferro- and silico- manganese alloys generate large amounts of off-gas that contains substantial amounts of dust, heavy metals and organic by-products. The dust is separated from the gas in venturi scrubbers by washing with water. The water is cleaned and recirculated, and the surplus water coming from moisture in the raw materials, is discharged to the adjacent fjords after further treatment. Emission figures show that the discharge of suspended solids, manganese, zinc and PAH (polycyclic aromatic hydrocarbons) have been reduced substantially over the last three decades as a result of process improvements and installation of state of the art environmental control measures. The two plants were the first world wide to install mercury cleaning of the off-gases from the furnaces. Mercury emission reduction has exceeded 90%. Concerning other environmental issues, such as utilisation of off-gases for energy recovery and chemical purposes, both plants have achieved good results. Major effort in the environmental work has come from the plants themselves, but other players like FFF, The Norwegian Ferroalloy Producers Research Association, and SFT, The Norwegian Pollution Control Authority, have contributed to the achieved results.

Jan 1, 2007

By S. Kelebek, E. Yalcin

"Two composite samples of a gold-bearing ore from North Western Quebec (Barry Township) were tested to assess their grindability, recovery by flotation and Knelson concentrator as well as extraction using cyanidation.Work index values (BWi) for two composites were found to be 10.4 and 11.0 kWh/tonne, respectively. Flotation tests involved feed samples for which the particle size ranged from a P80 value of 205 ?m to 53 ?m, which resulted in gold recoveries of 91.8% to 95.8% (at gold grades of 130 to 140 g/tonne). Cyanidation tests indicated gold extraction levels ranging from 94.2 to 97.5%. Higher, recoveries were obtained at finer grind sizes and higher cyanide strengths. However, the grind size had a bigger impact on gold leaching. Gold grade and recoveries obtained with the Knelson concentrator device were lower than those obtained by flotation. Mass recoveries to concentrate products strongly depended on the fluidization pressure used. High gold recoveries can be obtained generally at low water pressures of 3 to 4 psi. Higher water pressures produced more selectivity at the expense of higher gold losses.It can be concluded that the gold ore samples tested have good characteristics due to moderate levels of energy requirement, high gold recoveries and extraction rates attainable.INTRODUCTIONBench scale testing of ore samples is an important step in the long series of metallurgical and economic studies involved in bringing new ore bodies into production (Coleman, 1980). Through a laboratory testing program, the behaviour of an ore in a particular process on a larger scale can be established. In an exploratory manner, this testing can be helpful for classification of ores in terms of “good ore” or “problematic ore” by providing preliminary information on recoverability of target minerals. Potential problems if any can be assessed by further investigation of products (e.g., middlings) obtained as a result of testing. A detailed bench scale experimental program in the metallurgical laboratory can also provide the background work for flowsheet development. Depending on the simplicity or complexity of the ore to be tested and type of details required from a testing program, the amount of samples required in the mineral processing laboratory can vary from several kg to more than one hundred kg depending on how detailed the metallurgical testing program is."

Jan 1, 2008

By A Maldonado, A Robert, K G. Mercer

The Hamersley Group in the Pilbara, Western Australia, consist of interlayered banded iron formation (BIF) and shale host rock formations within which a large number of open pit iron ore mines have been established. The slope stability of most of the mining excavations developed within these formations is controlled by the relatively low shear strength of the shale groups and shale bands, which are the weakest rock types. Shale formations range from fresh to highly weathered and are generally highly fissile when fresh, and clayey when weathered. An accurate understanding of the shear strength of these materials across the entire weathering continuum is therefore a key importance for assessing the slope stability of these mines.Historically defect laboratory testing results for the Pilbara mines have been analysed mechanically using direct shear testing (DST) to measure a number of geotechnical characteristics of the rock bedding and defects. This paper sets out the current practice in the industry in terms of the laboratory testing and presents a possible application of hyperspectral data to empirically correlate the shear strength of shale bedding with the relative mineralogy abundance on the bedding surface. This was achieved by creating both hyperspectral and geotechnical data sets for the same samples.In the study the shale samples were separated into three distinct assemblages: iron oxide + kaolinite, iron oxide + white mica + kaolinite, white mica + kaolinite, which had 40, nine and two samples respectively. Analysing these assemblages alongside DST data showed that samples with white mica had reduced non-variable shear strength, whereas samples with iron oxide + kaolinite had an overall higher shear strength but with a greater variance. It is inferred that the reduced shear strength in the white mica samples is due to the sheet (or plate) like structure of the mineral, giving it a weak stress plane. Confidence in the trends observed can be reinforced by expanding the data set in future works. The investigation also includes a discussion on weathering grade and addresses the question as to whether mineralogy abundances influence these characteristics in Hamersley shales.CITATION:Maldonado, A, Mercer, K G and Robert, A, 2017. The relationship between mineralogy and shear strength of Pilbara Hamersley Group shales across the weathering spectrum, in Proceedings Iron Ore 2017, pp 423–430 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

Influence of Frothers on Bubble Shape and Velocity Close to the Generation Point

Sep 13, 2010

By Klaus Stoss, Bernd Braun

The sinking and lining of a large mine shaft with 8.0 m i.d. and 1,133 m total depth is described in detail. The ground freezing method was applied to safely sink the shaft through unstable, waterbearing strata. Following a brief introduction to the geological and hydrological conditions and the owner's shaft requirements, is the general technical concept to sink and line the shaft. Particular emphasis is put on the lining system which has to provide stability and absolute watertightness for the lifetime of the shaft, even though mining takes place in its immediate proximity. Machinery and equipment used to execute the work are mentioned and commented. Furthermore, the excavation and lining of the large filling stations using rock anchors and shotcrete are described. Details on performance rates are given.

Jan 1, 1983

By M. Wong-Kian, L. A. Cornish, A. van Bennekom

Samples of four different satellite materials were prepared by either hot isostatic pressing (HIP) of the powder or tungsten inert-gas welding of rod onto a 316 L stainless-steel substrate. The samples were subjected to a series of comparative erosion corrosion tests, and generally the Hipped samples experienced between 13 and 24 per cent less loss in mass than the equivalent welded alloys. Resistance to erosion corrosion increased with increasing carbon, chromium, and tungsten contents. Metallographic studies indicated the differences in carbide content between the different satellite materials, and the differences in morphology between the Hipped and welded samples. Finer and more homogeneous microstructures were

Jan 1, 1995

By K. C. Tran

This paper reviews the advancement of measurement technologies for the control of raw materials processes in the basic industries. The combination of digital technology and on line spectroscopy enables the development of intelligent instruments for composition and particle size analyses in real- time high- frequency control conditions. In many industries, the applications result in productivity improvement and energy savings. Plant specific examples include operating experience and benefits realized in sorting, blending and beneficiation processes. Instruments of the future not only measure specific parameters of the process and monitor its own health combined with self-corrective mechanics but also acts with intelligence to effect the quality of the process or regulate the primary apparatus.

Jan 1, 2001

By A. G. Mayton

Vehicle vibration exposure has been linked to chronic back pain and low back symptoms among agricultural tractor drivers. The objectives of this study by the National Institute for Occupational Safety and Health (NIOSH) were to assess driver whole body vibration (WBV) exposures and recommend interventions to reduce the risk of back related injuries, particularly relative to vehicle jarring/jolting (the transient mechanical shock components of WBV). The methodology included collecting, from two independent samples, ?eld data and health and work history data of farm equipment operators. Data were collected during mowing, raking, baling, chiseling, tilling, and road travel for different model tractors. Spraying using a sprayer and shrub removal with a skid steer loader were also included. Based on ISO 2631 (1985), the American Conference of Governmental Industrial Hygienists, threshold limit values, presents 0.5 m/s2 as the action level recommended by the Commission of European Communities for overall weighted total RMS acceleration (vector sum for axes x, y, and z) [ACGIH, 2006. Threshold limit values and biological exposure indices. Cincinnati, OH]. WBV measured at the operator/seat interface exceeded this action level. The roughest rides and highest vector sum accelerations occurred with small utility tractor mowers (3.3 and 2.8 m/s2) and a skid steer loader (1.7 m/s2). Major ?ndings from health and work history data showed 96% of participants reported having to bend or twist their necks, although 24% reported neck symptoms. Sixty four percent of participating operators reported experiencing back symptoms (e.g., pain, aching, stiffness, etc.). Recommendations included: specifying a seat that ??better?? isolates operators from jars/jolts with new tractor purchases; maintaining the seat/seat suspension and replacing worn or damaged cushions with NIOSH tested viscoelastic foam padding; using larger diameter tires with radial ply instead of bias ply construction, particularly on small utility tractor mowers, to aid in attenuating ride ??roughness??; using a swivel seat to reduce the stress on the neck from bending or twisting; and improving efforts to educate owner/operators of the adverse effects of WBV exposures. Since the data presented in this paper were collected from two independent samples, the authors were unable to draw any correlations or etiological inferences from the study. However, results were compared and contrasted with other studies which included similar vibration measurements in agriculture.

Jan 1, 2008

By Manqiu Xu, Andrew Lee, Frederick D. Ford, Cara Wercholaz

"Platinum-group minerals (PGM) typically occur in such low concentrations that quantitative mineralogical evaluation is difficult or impossible. The FEI MLA system used by Vale Base Metals Technology Development has been successfully employed to produce large PGM data sets that are statistically robust. The MLA Sparse Phase Liberation mapping routine produces false colored images that accurately document mineral textures, including intergrowths between various platinum group minerals and between PGMs and other tellurides and sulfides. MLA PGM search results can be used in conjunction with mineral chemistry to calculate platinumgroup element distribution to minerals and the MLA PGM images can be used to produce model grade-recovery curves.INTRODUCTIONThe platinum-group minerals (PGM) found in Sudbury area deposits have been extensively catalogued and reviewed by many authors including, but not limited to: Farrow and Lightfoot (2002), Cabri and Laflamme (1984; 1976) and Cabri (1981). The PGM list currently used has 12 minerals summarized in Table 1. As noted by Farrow and Lightfoot (2002), platinum-group minerals in Sudbury are dominated by tellurides, bismuth-tellurides and arsenides, with an absence of platinum-group element (PGE) sulphides or ferro-platinum alloys such as tetraferroplatinum - PtFe."

Jan 1, 2011

By J. Lazareck

"XPotential Products Inc. has developed technologies to convert auto shredder residues and other forms of plastic waste into useful products such as posts suitable for retaining walls and parking curbs. The technology is competitive provided low-cost plastic waste is available, and could have applications throughout the world. The paper describes the technology used and illustrates the various processing steps. Development of the TechnologyPresently, state-of-the-art auto shredding yields approximately 75% ferrous and non-ferrous metals and approximately 25% by weight of auto shredder residue (ASR). Advances in metal shredding and non-ferrous metal separation technologies turned XPotential Products Inc.’s attention to ASR as a potential revenue source, or at least a means to markedly reduce the cost of disposal. This abundance of nuisance ASR was, in the company’s view, a potential resource as derelict autos and white goods were similarly perceived 40 years ago. As owners of General Scrap & Car Shredder Ltd. in western Canada, XPotential faced significant disposal costs for four shredders. This journey began over 10 years ago and took many twists and turns until a final course of action was chosen. The recovery of the metallic portion of vehicles and white goods has reached technological maturity and attempts to add value are now achievable only in very small increments."

Jan 1, 2004

By J. A. Taylor, R. J. Fowell

Abstract: The amount of published literature pertaining to the field of rock mechanics has increased markedly in recent years. Whilst computer applications aid our understanding of the mechanisms of pillar instability, the applications do not take into account the effect of time; thus the determined pillar factor of safety has limited meaning. A more realistic approach would be to consider pillar stability in terms of time to failure. However such an approach would require a reasonable estimate of the in-situ pillar mass strength and a validated methodology linking the time to failure with in-situ pillar mass strength and the geometric layout of the working. Résumé: Le volume de bibliographie au sujet de la mécanique des roches a augmenté considérablement ces derniêres années. Alors que des modeles informatiques aident a la compréhension des mécanismes d'instabilité de pilliers, ces modèles ne prennent pas en compte les effets du temps; ainsi, la determination du coefficient de surete du pillier a un sens limité. Une approche plus réaliste devrait considérer la stabilité du pillier en fonction du temps de défaillance. Cependant une telle approche exigerait une estimation raisonnable de la resistance du massif rocheux du pillier ainsi qu'une méthodologie qui lie le temps de défaillance avec la résistance in-situ du massif rocheux du pillier et la géometrie de l'excavation souterraine. Zusammenfassung: Die Anzahl der Veröffentlichungen auf dem Gebiet der Felsmechanik ist in jüngster Zeit sehr gestiegen. Computerprogramme sind wertvoll um den Mechanismus der Pfeilerunbeständigkeit zu verstehen, aber sie vernachlässigen den Zeiteffekt. Daher haben die errechneten Sicherheitsfaktoren der Pfeiler nur begrenzte Bedeutung. Eine realistischere Bewertung wäre, die Stabilität der Pfeiler auf Grund der Zeit bis zum Verfall zu beurteilen. So ein Verfahren würde eine Schätzung der in-situ Gebirgsfestigkeit und eine validierte Methologie, die die Zeit zum Verfall in Abhängigkeit der in-situ Pfeilerfestigkeit und der geometrischen Auslage der Grube zusammenbringt, brauchen.

Jan 1, 2003

By Onuralp Yücel, Süheyla Aydin, Erçin Ersundu

Turkish iron and steel sector, the base of which was established in the 1930?s, plays an important role in the industrialization and development of the country?s economy. In Türkiye this sector is the major consumer of ferroalloys. There had been a great improvement in Turkish Iron and Steel industry, especially after the 1980?sand as a result, 20.9 million tons of yearly crude steel production placed Türkiye 11th in the global steel output and 3rd in Europe. 15 % of steel produced in Türkiye is flat products, while the long products make the rest. The product composition and the general characteristics of steel production process led to an increase in ferroalloy consumption. Domestically consumed ferroalloys are especially ferromanganese, silicomanganese, and ferrosilicon. As of today, ferroalloy production capacity of Türkiye is 173,800 tons/year; 161,500 tons of which is ferrochrome with high and low carbon grades, 7,300 tons of ferrosilicochrome and the rest is ferrosilicon (5,000 tons/year). Türkiye is one of leading ferrochrome producers in the world considering the above mentioned production figures. However, this production is mainly exported since Türkiye?s stainless steel production level is modest requiring low amounts of ferrochrome. The products of iron and steel industry in Türkiye require large quantities of other ferroalloys, which make Türkiye a major importer and exporter of ferroalloys. The aim of this work is to present production, consumption, import and export quantities of: ferrochrome, ferromanganese, ferrosilicon, ferromolybdenum, ferrotungsten, ferrotitanium and ferrovanadium of Türkiye, between 1990 and 2006.

Jan 1, 2007

By Chris Uys, Johan Labuschagne

Sishen Iron Ore Mine, located in the Northern Cape, is an open cast mine excavating approximately 100 million tons rock to produce 25 million tons of high grade haematite ore per annum. The size of the pit is approximately 12 km ‘1.5 km ‘150 metres. The final depth is planned to be around 350 metres. It is hard rock mining operation employing the conventional truck and shovel method. Mining benches are twelve and a half metres in height and are divided into blasting blocks, each consisting of approximately 300 000 tons of material.

Jan 1, 1997

By J. Humphries

With today?s turbulent markets and unprecedented global opportunities, the need to optimize net present value and internal rates of return from capital investments has never been greater. To help address the need, this paper presents an overview of the key processes and strategies for achieving maximum return from capital projects. Best practices discussed address stage gate management for project evaluation, selection, and oversight, project execution efficiency, value improving practices, operational readiness, and operational excellence. The paper also includes a model of key metrics and benchmarking with tips for application. [ ]

Jan 1, 2011

By Kazuo Magata, Hirohiko Fujita, Masazumi Tashiro, Yoshiaki Sato, Yoshio Shinoda

The Shinkansen of the Japanese National Railways (JNR) presently in operation between Tokyo and Hakata, approximately 1,000 km, was constructed at three stages: between Tokyo and Shin-Osaka opening in 1964, Shin-Osaka and Okayama in 1972 and Okayama and Hakata in 1975. Works on the extension of 400 km from Okayama to Hakata were launched in March 1970. As construction of the undersea Shin-Kanmon Tunnel on the extension was the toughest task, requiring many, many months, the work was undertaken earlier than any other works on the extension. It was brought to its completion in June 1974 at the cost of about 22, 000 million yen. The Shin-Kanmon Tunnel is the third undersea tunnel constructed to connect the main island of Honshu and Kyushu across the Kanmon Straits. (Table 1)

Jan 1, 1976

By J. W. Allen

This report reviews the work performed on Task M of Bu-Mines Contract H0220073 to develop an engineering model of a surface and subsurface communications system for normal mine operations and for post disaster rescue operations. The system concept provides for one-way transmission of digital information between a number of identifiable subsurface terminals or subcenters and a single surface station. It also provides 2-way voice communications between the subcenters and the surface station. The basic communications link is electromagnetic signaling through-the-earth, but the system is also capable of using mine phone lines as an alternate link. Engineering models of three subcenters and one surface terminal (see Figure 1-1) have been fabricated in order to demonstrate the system's performance. The system concept, however, permits up to 20 subcenters to be incorporated if desired. Additional subcenters are also feasible for large mines if they can be deployed in the mine to operate on a noninterfering basis.

Jan 1, 1973

By T. Ertekin, X. Dong

This paper identifies the need for the development of specialized inverse solution techniques for the analysis of pressure transient data for the characterization of the transport and sorption properties of coal seams. Central to the proposed inverse solution technique is a specially structured artificial neural network (ANN). The most important transport and sorption characteristics of coal seams are butt and face cleat permeabilities, macropore porosity, Langmuir volume constant, Langmuir pressure constant, and sorption time constant. Conventional methods, such as type curve matching techniques and laboratory-derived measurements are handicapped in terms of being representative over the entire domain of interest. In this paper, we utilize analytical forward solution techniques for various combinations of characteristics of coal seams to generate training and testing patterns. These training patterns are shown to an ANN structured to learn the ubiquitous non-linear relationships that exist between coal seam properties, input conditions and the pressure transients measured. The trained networks are then extensively tested to ensure that they have effectively learned the training patterns. In the final stage of the development, the networks are run in the prediction mode. The responses of the networks are found to be in agreement with the input data. The developed networks are able to generate results generally within 5% error margin for permeability and porosity and 20% error margin for the sorption characteristics of coal seams. A number of examples highlighting the capabilities and degree of effectiveness of the network in characterizing the coal seams areincluded. Keywords: artificial neural networks (ANNs); coal seam characteristics; pressure transient analysis

Jan 1, 2003

By F. Habashi

The first documentary evidence for the use of fire to extract a metal was furnished by the wall paintings of the ancient Egyptians showing workers using the blowpipe and bellows to increase the temperature to melt gold in a crucible. Furnaces grew in size and complexity, coke replaced charcoal in the blast furnace, and the Industrial Revolution took place in England that gradually spread worldwide. More metals became known and new techniques were introduced for their extraction. Among these, metallothermic reactions became prominent in the nineteenth century immediately after the discovery of the electric current and its use to liberate the alkali metals from their salts. Once these metals became available, they were used to produce aluminium from alumina that resisted all other methods of attack. Aluminium, now available on a large scale, was used to decompose the most stable compounds and liberate more metals that became the basis of modern civilization.

Jan 1, 2004

Mineral Processing Education in China

Sep 13, 2010

By J. Cayouette

In 1995, Louvicourt mine started one of the first paste backfill operations in Canada. From 500 000 t in 1995, the annual paste backfill tonnage produced reached 800 000 t in 1999. The maximum throughput of the surface plant (including binders) is 3500 tpd with a final density of 75% to 76% solids which gives a slump of 15 cm to 17 cm. Following the start-up of the paste backfill plant, the backfill strength performance levels were well below the pilot plant’s predictions. The introduction of ferrous slag, laboratory tests on various binder ratios with or without additives, and the desliming of the tailings enabled us to optimize the mix and operation costs. Primary and secondary stopes are filled respectively with a paste containing 4.5% and 2% binders in a mixture of 20% cement to 80% ferrous slag. In certain stopes, the binder ratio may vary from 2% to 7%, but always in a ratio of 80/20. Six years after start-up, or 4.5 Mt of paste backfill later, this paper discusses the present operation and the major changes that have occurred over the years to optimize both the operation and the paste fill quality.

Jan 1, 2003