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Based on the examination of thirty sets of contiguous matte and slag samples taken from industrial nickel smelters a relationship is predicted between oxidic nickel in slag, oxygen in matte and the Ni/Fe ratio in the matte. Oxidic nickel in the slag is found to increase with an increase in oxygen content of a matte of constant Ni/Fe ratio, and it is proposed that the relationship may be used to predict nickel solubility in slag from a knowledge of matte composition alone.

Jan 1, 1980

By None None

Use this month wisely — go online and take advantage of your new member benefit. As an SME member, you can read and download for free all of the full-text papers of the Mining, Metallurgy & Exploration (MME) journal, including the 22 papers in the launch Special Issue on Mineral and Metallurgical Processing in Honor of Professor Emeritus Douglas W. Fuerstenau as well as the archived articles of Minerals & Metallurgical Processing (MMP), all the way back to Vol. 1, No. 1. Just follow the instructions on this page.

By W C. Cook, S J. Mathews, A H. Purvis

The Golden Cross Gold Mine is located at the head of the Waite kauri Ri ver, 8 km northwest of Waihi near the southern end of the Coromandel Range. The mine produces gold and silver from epithermal veins hosted by Miocene andesitic flows and pyroclastics of the Coromandel Group. Golden Cross is owned in joint venture by Coeur Gold NZ Ltd (80 per cent) and Viking Mining Company Ltd (20 per cent). Mining is by open pit and underground methods. Mineralisation in a near-surface sheeted/stockworked vein zone is mined from the open pit. The deeper Empire Vein System is mined from underground where higher grade mineralisation is restricted to generally discrete veins. The open pit stockwork zone is west of and offset from the updip trend of the Empire Vein System. The Empire (hangingwall) Vein strikes generally north-northeast and dips steeply west. Dips become subvertical at greater depth. The hangingwall vein is a well developed, generally continuous structure with relatively high gold grades. A complex footwall vein system forms shallow west-dipping offshoots to the hangingwall vein. Structure and gold grades become increasingly erratic away from the hangingwall vein. The better developed footwall veins carry economic grades and high 'spot' grades over 50 g/t Au are not uncommon. Highest gold grades are associated with tightly crustiform banded sections of quartz veins and with dark fine grained siliceous breccias. The main hangingwall vein occupies a major north-northeast trending fault structure, the Empire Fault. Footwall veining forms within subordinate splinter fault zones. There has been extensive multidirectional pre-, syn- and post-mineralisation faulting. Fault manifestation is highly dependent on host rock characteristics. The central part of the hangingwall vein and surrounding silicified country rock has been shattered by a major fault structure, the West Mine Fault, forming a poorly consolidated, blocky quartz-breccia ore zone. Away from the more brittle ore zones and associated silicified envelope, wide clay-filled shears mark the major fault trends. Development of the deposit is considered to have occurred in two distinct stages related to separate episodes of dilational jog movement on the Empire Fault. The first phase reactivated the pre-existing Empire Fault as a dilational fissure with subordinate splinters on the footwall side. The Empire Vein System (hangingwall and associated footwall veining) formed during this phase. A second phase of renewed movement with further dilation resulted in more extensive fracturing of the Empire Vein and surrounding country rock and formed the sheeted/stockwork veining of the open pit. An upwards/westward migration of the hydrothermal system is assumed but fluid pathways between underground and open pit veining are unclear. Ore extraction and mining geology methods have responded to improved understanding of the grade and structural variability, and changing ground conditions inherent in the vein system. The underground mine produces ore from flatback cut and fill, post-pillar and bench stopes. Open pit and underground ores are campaign milled through a conventional CIP plant.

Jan 1, 1993

By G Tripp, G Lorusso

The Velvet gold orebody (153 Koz Au) is located near the Kanowna Belle gold deposit in the Boorara Domain of the Kalgoorlie Terrane, a subdivision of the Archaean Eastern Goldfields Superterrane (Swager et al, 1990). Gold mineralisation at Velvet is hosted within an intrusion of intermediate composition that broadly follows a sub vertical hanging wall splay of the Fitzroy Shear Zone.Velvet was discovered in 2003 during an underground exploration drilling program targeting potential strike extensions to the Kanowna Belle deposit. Diamond drill hole KDU1595 returned a downhole intercept of 36 m grading 4.6 ppm Au approximately 500 m west of the deposit and at a vertical depth of 700 m below surface in the immediate hanging wall of the primary Kanowna Belle host structure, the Fitzroy Shear Zone. Subsequent drilling completed following the initial discovery, from both surface and underground collar positions, failed to replicate this result.In 2014, KDU1595 was resurveyed gyroscopically and the mineralised intercept correctly located. Additional drilling was undertaken to follow-up the repositioned discovery hole. Challenges included poor drilling angles through the Fitzroy Shear Zone, excessive deviation during drilling and the unknown geometry of the target. Navigational drilling helped to successfully penetrate the Fitzroy Shear Zone and in April 2015, drill hole KDU3234 returned a significant downhole intercept of 45 m grading 5.6 ppm Au.Additional drilling success resulted in a decision to develop a 600 m drive to serve as a dual-purpose access for further exploration and mining. This was a potential risk considering that the orebody geometry was unknown and all significant drilling results were clustered within a 50 m × 50 m panel. Development commenced in June 2015 and the first ore cut taken in April 2016. Geological mapping and structural interpretation, together with multi-element and spectral analysis of drill samples has enabled several other target areas to be identified for exploration. The Velvet mining area is critical to continued production at Kanowna Belle. Geological understanding must advance as mining progresses to ensure continued resource growth and optimal extraction of reserves.CITATION:Lorusso, G, Rogers, J and Tripp, G, 2017. Velvet underground exhumed – discovery and development of a new mining front at the Kanowna Belle gold mine, in Proceedings Tenth International Mining Geology Conference 2017, pp 169–174 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

The construction of the pipeline was completed in June 1956 and the line placed into operation in December 1956, ie. it has now been in continuous operation for approximately three years under an operating pressure of up to 350 lb. p.s.i.In reviewing the operating experiences of the line we must consider three major factors, which are:(a) The effectiveness to date of the protective methods for prevention of corrosion of the pipeline, ie. the preservation of the asset.(b) The maintenance of the line in regard to interference as to its stability which could be occasioned by erosion of the line, land-slides, accidental interference by the public, or construction authorities, etc.(c) The operating techniques employed.PROTECTIVE METHODS OF THE PIPELINESo to permit a clearer appreciation of the effectiveness of the protection of the! steel pipe against corrosion, I will briefly describe the methods used in the construction of the line.The line, which is 18 in. O.D. by %6 in. thickness steel pipe, is located approximately It miles south of the main Melbourne/Gippsland electrified railway.The steel from which the pipe was manufactured conforms to ASA.A33-1937 with the following modifications.Minimum elongation on a 2 in. test specimen...

Jan 1, 1960

By John C. Machisak

STATISTICAL data on injuries and employment pertinent to metal mines and to their mills, and/or processing plants are presented in this Information Circular for the calendar year 1960. The information pertains to metal mines, as well as ore-dressing plants and primary nonferrous smelters, refineries and reduction plants, and their auxiliary works. These data are voluntarily submitted annually to the Bureau of Mines by the operators, and contribute greatly toward the promotion of safety in the mineral industries. The data presented are classified according to the principal mineral produced and include information on copper, iron, lead-zinc, gold-silver lode, gold placer, uranium-vanadium and miscellaneous metals. A breakdown of miscellaneous metals by commodities is shown in table 19, page 41. The data also relate to workers engaged in production, exploration, development, construction, and maintenance and repair work, as well as supervisory personnel and office-workers at the mine or plant site. Injury and employment data at metal mines and metallurgical plants in the United States for 1960 are shown under the following general sections: 1. General injury experience: Tables I-5-Data on injuries, injury-frequency and severity rates and related employment data, work location, and degree of injury.

Jan 1, 1963

By W. Smith

The U.S. Bureau of Mines (USBM) is using laboratory and computer-based techniques to investigate the post- failure behavior of yielding pillars and pillar reinforcement techniques to control entry deformation. Poorly dimensioned yield pillars, can cause adverse ground conditions. Laboratory studies to evaluate various reinforcement techniques for controlling yield pillar deformation were conducted. A cracking and crushing model is used to evaluate potential tensile and compressive failure planes within pillars of various widths to assess the degree of yielding and stress redistribution. The use of an elasto-plastic model to evaluate the effect of various reinforcement on yield pillars is also discussed. These procedures effectively account for the residual pillar strength, important in yield pillar design.

Jan 1, 1995

By John Lindsay

"Although diamond mining is a relative newcomer to the Canadian mining industry, with the first diamond mine coming on stream in 1998, Canada is already a significant producer of high quality diamonds. This paper will review diamond production trends and highlight some of the projects currently under development, which have the potential to enhance Canada’s role as a significant diamond producer.Diamond recovery plants generally incorporate well-established mineral processing and recovery techniques, with issues such as product security, cut-off sizes, and diamond preservation becoming important considerations when developing process flowsheets. A diamond processing plant must achieve three key objectives, namely:• Liberation of the diamonds from the host rock;• Separation of the heavy minerals, which include the diamonds, from the host rock;• Recovery of the diamonds from the heavy mineral concentrates.Processing technologies and equipment commonly utilized in diamond processing plants will be reviewed and some of the significant issues associated with each option briefly discussed.Typical process flowsheets will be presented.Finally, an overview of De Beers’ Victor diamond project, located in northern Ontario, will be provided. This potentially significant diamond producer is currently at a pre-feasibility stage of development.DIAMONDS IN CANADAWorld Diamond ProductionCommercial diamond mining commenced in earnest with the discovery of the Kimberley diamondfields in South Africa in the late 1800s, and this resulted in a dramatic increase in the supply of diamonds. As can be seen from figure 1, world diamond production, mainly from South Africa, Angola, Congo, and Namibia, remained relatively constant through the early 1900s until the development of the large Russian kimberlite pipes in the 1950s. Production increased again in the 1960s and 70s with the development of the Botswana mines, but the most significant increase in global production came from the Argyle mine in Australia, which came on stream in 1983 and produced a peak of almost 43 million carats in 1994, representing approximately 40% of the world market. Production from Argyle has since fallen-off as grades have declined and the strip ratio has increased with the deepening of the open pit."

Jan 1, 2003

Engineering education has become a matter of national concern, at last, so I would like to talk about the links between the mining industry, the universities and technological developments. The Australasian mining industry and the mining schools have collaborated closely since the first school was established in 1871 and during those years there were a series of remarkable technological developments. For example:In the late 1880s George AndersoIl Richard developed chloride leaching of gold at Mt Morgan. This made a large difference to the wealth of Mt Morgan Mining Ltd.In the mid 1890s Robert Sticht demonstrated that pyrite smelting was an economically feasible process at Mt Lyell and the wealth which came to Mt Lyell Mining Co from his outstanding work made it one of the great companies in the country.During the first 15 years of this century flotation was developed at Broken Hill and it has proved to be one of the great technological inventions of this century.In the 1920s G K Williams started his outstanding work on lead smelting and refining at Port Pirie, this was work which ultimately re-wrote the text book on lead metallurgy and established Port Pirie as the mecca for lead metallurgists.In the 1920s also Frank Stillwell, later joined by Austin Edwards, established the new science of mineragraphy at the University of Melbourne. They were both great geologists, both were superb scientists and oddly enough both were outstanding athletes.In the 1930s Dr Ian Wark, a man in the front rank of Australian scientists of any period, started his outstanding work on flotation, work which resulted in a text book which remains a leader in its field today.In the 1930s also Arnold Black at Broken Hill South Ltd picked up the work which had been done at Mt Lyell many years previously and eventually wrote the papers on hydraulic fill which demonstrated that he led the world in fill technology. What a remarkable story of achievement it was, it laid the groundwork for the great industry we have today. It was possible because the industry was well supported by outstanding university schools and I would like to talk about some of these.

Jan 1, 1989

In general, the metallurgical industry has so far been slower than the chemical industry to adopt ion exchange materials for industrial processes. The atomic energy industry presents a marked exception to this general situation, and the literature shows a rapidly increasing use of ion exchange techniques for the recovery of atomic energy metals on scales ranging from the ultra micro up to that of the largest mining operations. In many cases, the processes used would be equally applicable to more common metals and it is hoped that this review will be of interest to metallurgists outside the specialised atomic energy field. The review is intended to describe developments of ion exchange processes made during the last three years. Earlier studies have been summarised by Kunin and Preuss (1956) and Roland (1957). In order to restrict the number of references discussed, purely analytical procedures have been omitted and only those processes which have been conducted on a reasonably large scale or which, from their nature, areclearly capable of being upscaled, have been considered. The paper is divided into five main sections concerning respectively:Water treatment and effluent disposal.Metal recovery and purification.New ion exchange materials.New ion exchange equipment.Membrane cells.WATER TREATMENT AND EFFLUENT DISPOSALA high proportion of atomic reactors, and particularly those of American design, are cooled by water which is...

Jan 1, 1961

This paper reviews the gold mining history and recent exploration activities on a number of beaches in the Catlins area of coastal South Otago. Past mining history and recent sampling indicate the presence of economically significant concentrations of placer gold, as well as anomalous PGM, and various heavy mineral species. A local source for this placer mineralisation is considered a strong possibility, along with a contribution from the Waiau River catchment via longshore drift. Blacksand beds in Jurassic sandstones of the Southland Synclinorium may represent this local source of mineralisation on the modern beaches. The possibility of placer mineralisation extending onto the inner continental shelf is also considered. Further exploratory work is justified, both for in situ Jurassic blacksand deposits, and to delineate mineralisation in the modern beach and inner shelf environment.

Jan 1, 1992

By Paul H. Atkinson

"Sampling in the mineral processing industry has always been a subject which has received considerable discussion. There have been many volumes written on theory, techniques and practical application of sampling. However, until recently, the companies were not completely aware of the potential savings available with properly designed sampling systems both to assist in pieces: control and final product values.Definition In our discussion today, we will define sampling as the operation of removing a part, convenient in quantity for analysis, from a whole, which is of much greater hulk, and removing it in such a way that the proportion and distribution of the quality to be tested, i.e. size of particle, moisture content, specific gravity content, mineral and chemical composition, are the same in both the sample and the whole.Application It has been well established that undetected errors can result in large economic losses, thus most firms depend upon some type of sampling and sample analysis as a control in their continuous processing of materials. Despite the large investment in facilities and personnel the ""analysis"" of a sample can be no more accurate or reliable than the sample on which it is being based. The importance of sampling is recognized by a great many but it is appreciated by only a few, largely because it is sometimes one of the items which is taken for granted."

Jan 1, 1976

Several economic factors have caused the surface mining industry to require large-capacity shovels and trucks for efficient, high-production, low-cost operations. Some of those factors include technological advancements in equipment, commodity market depressions, increased labor and maintenance costs, contractural obligations and harsh operating conditions. The difficult operating conditions in surface mines, however, pose challenges to the use of high-capacity equipment. They include space limitations, weak over-burden, and weathered soils and rocks. So mining companies face major challenges in selecting appropriate shovels to meet the technical, operating, safety, environmental and economic requirements of their mines.

Jan 1, 2003

Jan 1, 1961

By Ning Wang, Tengfei Guo, Wanyan Li, Hanjie Wen, Hannian Gu, Zehai Li

Bauxite residue (red mud) is an alkaline waste derived from the industrial process for extraction of alumina from bauxite ore. Some bauxite residues contain considerable concentrations of critical metals, for example, rare earth elements. Lithium in red mud was also reported as a potential resource. In the current study, a Li-rich red mud was leached using acetic acid to investigate the leaching behavior of lithium followed by neutralizing with hydrochloric or oxalic acid. By neutralizing red mud using diluted hydrochloric acid (0.01 mol/L), 58.04–60.27% of lithium was leached using 25% acetic acid at 95 °C for 60 min. In the meantime, more than 95% of sodium and 85% of calcium were also dissolved in the leachate solution. While oxalic acid (0.5 mol/L) was used to neutralize red mud prior to acetic acid leaching, lithium performed lower leaching efficiencies (42.41–46.88%) in comparison of using of hydrochloric acid–neutralized red mud. Nevertheless, these leaching efficiencies of lithium were close to that of calcium and much higher than those of sodium under the condition. In this study, 25% (v/v) of acetic acid, at 85 °C for 60 min, was demonstrated as optimum conditions for lithium extraction from oxalic acid–neutralized red mud using acetic acid. The results would be useful and of interest for lithium recovery and purification from red mud.

By J. H. Brophy, M. H. Kamdar, J. Wulff

A constitutional diagram for the Ta-W-Re alloy system is presented. Rhenium dissolves in the complete range of solid solutions between tungsten and tantalum up to 48 wt pct in tantalum 'to about 30 wt pct in tungsten. Intermediate x and u phases only are found. X-ray diffraction and fluorescence, metallography and melting-point measurements were employed. THE constitution diagram of ternary alloys of tungsten, tantalum, and rhenium for temperatures above 1000°C is reported in this paper. Alloys in this system rich in tantalum and tungsten are of interest for high-temperature applications, and those rich in rhenium for electronic applications. No ternary phase diagram appears to be available in the literature. The three-component binary diagrams have been previously established1-3 and the present ternary data are consistent with these. EXPERIMENTAL TECHNIQUES Commercially pure tantalum (99.7 pct), rhenium (99.99 pet), and tungsten (99.9 or 99.95 pct) powders were purchased from Fansteel Metallurgical Corp., Chase Brass and Copper Co., and Fansteel or Westinghouse Electric Corp., respectively. These powders were pressed without binder and arc-melted under helium. The preparatory and analytical techniques employed were identical to those used for the Ta-Re system investigation carried out in this laboratory.324 These included X-ray diffraction and metallographic phase identification, X-ray fluorescent and wet chemical analyses, solidus determinations and heat treatments in a resistance-heated tantalum-filament vacuum furnace. For microstructural examinations standard mechanical polishing techniques were used through diamond laps. Polished speciments of all compositions were etched by swabbing with 4 parts HI?, 4 parts HNO3, and 1 part H20. Since the microstruc-tures of alloys containing one or two phases closely resembled their counterparts in the respective binary systems, typical examples are omitted in this presentation. In all the alloys examined, it was possible to observe the number of phases present. Particularly when there were small amounts of one phase involved, it was possible to identify it only by a combined conclusion based on X-ray diffraction, position of an alloy in a composition series, and the phase rule. A total of 100 different alloy compositions was arc-melted and studied in the as-cast condition metallographically and by X-ray diffraction. Specimens of each of these compositions were heat-treated at 2680, 2530, and 2020°C for 1, 2, and 4 hr, respectively. Those which were treated at 2020 were given a preliminary homogenization treatment at 2500°C for 1 hr. Specimens of 25 alloys were heat-treated at 1200o C for 168 hr. Solidus temperature measurements were made by the detection of incipient melting in eighteen alloy compositions. The metallographic and X-ray diffraction results are summarized in Table I. Graphically, this information appears in the isothermal plots of Figs. 2 and 3. Within the accuracy of the experimental methods, two such plots are sufficient to locate these data, since the results for 1200°C were similar to 2020 and those at 2530 resembled 2680

Jan 1, 1962

By R. W. Heins, N. Street

An investigation was made of the Rehbinder-Kuznetsov pendulum as an instrument to aid in the study of rock drillability and of the effect of surface active agents on rock drillability. The "critical weight", i.e., the pendulum weight at greatest sensitivity, was determined for several solids and it was shown that a change in surface environment changed the maximum value of the apparent hardness but not the critical weight, and the critical weight increased with increase of hardness of the solid used. Using silver halides as the solid material, and solutions of either silver nitrate or the appropriate alkali halide, it was shown that there is a hardness maximum at the zero point of charge of the particular silver halide. INTRODUCTION The development of relative hardness measurement by the method of damped oscillations, or what has been called the pendulum sclerometer, is due largely to the Russian workers P. A. Rehbinder and V. D. Kuznetsov and their co-workers.1,2 The apparent simplicity of the method has led to its use in a number of fields, particularly those where relative hardness has to be determined on a brittle solid. As will be shown, the simplicity of the method belies its complexities. THEORY OF THE PENDULUM SCLEROMETER The operation of the pendulum is quite simple. Make a sharp point such as a diamond, hardened steel or tungsten carbide, as the fulcrum of a pendulum, with the center of gravity of the system below the point of support. The attenuation of this pendulum is a function only of air friction, provided no fragmentation, breakage or other work is performed by the point. However, when the solid surface breaks or disintegrates under the point, and the latter penetrates the solid, part of the energy of oscillation is absorbed in the work of creating new surface, and the rate of attenuation increases. In the case of brittle solids, the point of the pendulum produces fragmentary particles, whereas the point produces plastic deformation in a plastic solid; but in both cases damping occurs. This pendulum damping is a function of the hardness or strength of the solid. Whereas a pendulum oscillating on a hard material attenuates primarily by air friction, in the case of a soft material, the points penetrate the surface of the solid, producing new surface, and the pendulum damps much faster. Thus the attenuation rate is a function of the hardness or strength of a material in both plastic and brittle substances. Russian workers initially used a single support for the pendulum, but this created many problems because of oscillation of the pendulum in more than one plane. A revised version used two points, or sometimes a prism as support, successfully confining oscillation to one plane. The version using two points was constructed and used throughout this investigation, making the recording of the attenuation as a function of time relatively easy. That both points should be in contact with the solid during the damping is implied. Rehbinder (c.f. Kuznetsov2) proposed that the hardness H as measured by this method could be expressed by a quantity which is inversely proportional to the relative initial rate of attenuation of amplitude. where H = hardness parameter (arbitrary units) a, = initial amplitude da/dt = rate of attenuation of amplitude with time. In the simplest case of damping with a constant logarithmic decrement, H can be regarded as a constant for the duration of the whole damped oscillation process. That is

Jan 1, 1966

By Alexander Nikolic

The paper presents the foundation design and construction of a landmark urban redevelopment scheme in central London, UK. The scheme comprises the new Tottenham Court Road Underground station, Crossrail interchange box and associated over-site commercial development. The paper focuses on the design, procurement and construction of large diameter bored piles, up to 68m in depth, which form the foundation support system for the over-site commercial development at Denmark Place. The congestion below ground required an intricate foundation design solution which has been a catalyst for developing innovative load transfer arrangements and has resulted in the advancement of pile construction technology in the UK. The foundation system was also designed to cater for the construction of two significant elements of proposed below ground infrastructure. Selected large diameter piles have been constructed within 1.1m of live underground railway tunnels. An innovative D-shaped pile was constructed in a zone subject to particular spatial constraints. The proposed Crossrail tunnels will be bored within 1m of selected over-site development piles. In addition, a 30m deep excavation forming a new escalator box will be constructed in direct contact with the over-site development piles. The stakeholder engagement process is described together with the foundation design development and buildability assessment. The benefits from early collaboration between the designers and specialist contractors are highlighted. From an analytical design perspective, the entire foundation construction sequence was modelled in detail in order to assess the soil structure interaction and any potential adverse effects on existing elements of underground infrastructure. The results from the three dimensional numerical modelling simulation are compared with field monitoring data.

Jan 1, 2011

By Bernard H. Hertlein

Transportation system structures have come under very close scrutiny in the last couple of years, largely due to the damaging effects of disasters, both natural and man-made. In the Pacific northwest and California, earthquake risk is a major concern. In the central and eastern states barge impacts on bridge piers and docks are a big worry. In all cases of bridges over water and waterside structures, scour is a primary concern. Some of the results of this scrutiny have been changes in design and construction methods, and the introduction of more testing to supplement field inspection during construction, and throughout the service life of the structure. Future construction of bridges and docks will almost certainly see a continuing growth in these practices. Where foundations are concerned, particularly for bridges and waterside structures, many state and local authorities have started specifying drilled shafts rather than driven piles. Where the shafts must be constructed under water or slurry, visual inspection of most of the work is impossible, and one of several different Nondestructive Tests (NDT) is often specified. Contractors' experiences with these methods have varied considerably, and there is a great deal of controversy in the deep foundation industry over the reliability of NDT methods for assessing the integrity of foundation shafts or piles. The author has had more than 15 years of practice with the various NDT methods for deep foundations, on projects all over the US, particularly foundations for bridges and dock structures, and has developed an understanding of the "NDT controversy" as it has become known. In particular, experiences in the Pacific Northwest, California, and Alabama have illustrated the reasons for the controversy. This paper reviews these experiences, and suggests some steps that owners and contractors can take to reduce the risk of inconclusive or downright inaccurate test results.

Jan 1, 1998

By H. Moosberg-Bustnes

In cement-based products, such as concrete and mortars, a balance between the particle sizes of the components must be kept in order to obtain the required material properties, such as workability and strength. Sometimes the aggregates lack the necessary amount of fines, hence fine particles, i.e., filler materials, have to be added. Large quantities of filler material are needed in the production of modern concrete types; one principle of self-compacting concrete (SCC) is, for instance, the use of large amounts of fillers to reduce the friction between the coarser aggregates. Use of by-products such as slag, dust or sludge from the metallurgical industries as filler materials in concrete may help to conserve natural resources and at the same time be an economically positive option. However, to be able to successfully use the available materials they must be suitable for the planned purpose, i.e., they must be compatible with cement. In this paper three different experimental studies of steel-slags will be discussed. The aim of the studies has been to investigate if it is possible to improve the steel-slags properties, by selective screening, fine wet grinding or remelting, so that the steel-slags can be used as mineral-addition/filler material in concrete. Keywords: concrete, filler, steel-slag, modification

Jan 1, 2004