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By Hans D. Gougar

To meet an increasing demand for minerals, mining operations are moving to ever more remote regions. The lack of a local energy supply and infrastructure, coupled with social and regulatory demands for lowered environmental impact of mining operations, presents an opportunity for a seemingly unlikely competitor ? a nuclear power plant. The Modular Pebble Bed Reactor concept, currently in various stages of research and development around the world, offers a high degree of reliability and safety with minimal consequences for the local or global environment. The passive safety features of this design eliminate the need for the extensive active safety systems that add significantly to the cost of current water-cooled reactors. With the MPBR, as with all nuclear plants, there are no appreciable quantities of waste products released to the environment during normal operations. In contrast with conventional reactor designs, the MPBR would also remain radiologically safe even under the most severe abnormal circumstances. The key to the design is the fuel element. Enriched uranium microspheres are coated with various layers of pyrolytic carbons and silicon carbide to form a highly-temperature resistant particle that effectively retains all fission products. These particles are mixed with graphite and formed into 6 cm pebbles. A randomly packed vessel of such pebbles forms the reactor core through which helium is circulated as a coolant. Computer models and tests performed on actual pebble bed reactors confirm that fuel failure temperatures are not reached even during the most severe conceivable loss of coolant accident. The reactor drives a gas turbine cycle with resulting efficiencies as high as 48%, comparable to natural gas-fired units. The low price of uranium fuel and low maintenance requirements translates into competitive operating costs. However, high capital costs prevent the MPBR from competing with natural gas in most markets. In remote applications where no fossil supplies are readily available, the playing field is more level. This paper summarizes the features of two of the more promising candidates for remote applications and discusses the strengths of the MPBR from the perspectives of fuel supply and environmental impact.

May 1, 2002

By R A. Medower

This paper provides a glimpse into the future of minerals processing with emphasis on æAutomation InnovationsÆ for the new millennium, particularly those involving advanced process control and innovative new applications of process control technology in 2007.

Jan 1, 2000

By J. Chretien

The ability to continuously monitor the air quality within a mine has become instrumental in becoming a low cost producer. The many considerations involved in monitoring air quality include sensor type, hardware placement, as well as data storage medium. BESTECH has had the opportunity to gain insight into these air quality monitoring considerations through deployments of NRG1-ECOTM, a minewide energy consumption optimization system. This paper explores the particular challenges overcome through these installations, and provides a set of guidelines for mines that want to maximize data capture while minimizing costs. It provides a view of additional benefits of air quality monitoring, such as ventilation control, reporting and trending.

Aug 1, 2013

By A. E. Koski

This paper describes the implementation of specialized software in mine planning at the Cleveland-Cliffs' managed Empire Mine on Michigan's Marquette Iron Range. The application puts together years of mining experience on the eastern end of the Marquette Range beginning in the early 1960's. The Empire Mine, in its thirty-fifth year of production, uses the software to model a complex and highly variable low grade magnetite ore body, capturing the economics of mining and processing to the final product. With special attention given to geostatistical methods, the software is used for all geologic modeling, ore reserve estimation, ore control, pit design and short and long range planning.

Jan 1, 1999

By N. Dobrin, R. Sheinman, Y. V. Kokotov, L. N. Braginsky

Increasing the production of a Mixer-Settler unit requires either increasing flow rates or increasing extractant concentration. The mixers still have to ensure complete emulsification and to maintain high values of specific interface surface area in order to provide a high rate of mass transfer. Theoretically, an increase in mixing intensity can support increased flow rates without reducing extraction efficiency. Unfortunately, conventional pump mixers and mixing systems create small droplets that do not separate easily. As pumping action and mixing intensities are increased, the quantity of small droplets increases. We describe the development and industrial application of a novel mixing system for efficient mass transfer without forming significant quantities of small droplets, targeting both high mass transfer rate and low entrainment values.

Jan 1, 2014

By D. R. Zuchelli

The purpose of wrapping ball mills with thermal/acoustic blankets is twofold: 1) to maintain the desired temperature inside the mill, and 2) to reduce the sound emanating from the mill. This field case study focuses solely on the latter, evaluating and documenting the sound level reduction attributed to the installation of the blankets on ball mills and its potential to reduce the noise dose experienced by the process attendant. One of the three ball mills had already been treated (baseline) before the evaluation started. However, treating the remaining two mills still proved to be very effective, further reducing ball mill noise in the near field by as much as 10.0 dBA and producing far field noise reductions of 3.0 dBA or greater, extending as far as 35 feet from the mills and to the floor above. The model developed from the survey data shows that a process attendant spending a substantial portion of a shift in the mill building will experience a significant reduction in overall noise dose.

Jan 1, 2010

There are many compelling reasons why correct sampling schemes should be standard practice in the mining industry, yet there are numerous examples where poor sampling practices are known to exist in the business yet permitted to continue. It is not just technical issues that can be ascribed to the reasons for the continued use of incorrect methods. This paper proposes non-technical reasons why incorrect sampling practices continue, and identifies potential ways to overcome them.

Mar 1, 2010

By Gerald Blackmore

This paper discusses the present state and future trends within the coal industry, and then goes into the reasoning behind these planned trends. Such factors as marketing, costs, new mining techniques and machinery, and manpower and human resources are considered. Finally, the author refers to the effect that these trends will have on the coal industry of Cape Breton.

Jan 1, 1968

By J. Hunter

The Highland Uranium Project in Wyoming is an in-situ leach (ISL) facility owned and operated by Power Resources Inc. It is the largest uranium producer in the U.S. and the largest uranium producer by ISL in the western world. With its limited capital investment and low operating costs, the ISL technique has been demonstrated to be an effective and environmentally sensitive method for recovering minerals from these low grade and otherwise uneconomic orebodies.

Jan 1, 1996

By Robert Alperstein, Nidal AbiSaab, Joe Pastore

"This paper describes the design and construction aspects of the foundation support for a 57-story building currently under construction in lower Manhattan. The site is located near the East River with subsurface conditions consisting of about 40-ft [12.2-m] of unsuitable historic fill and soft plastic clay underlain by about 130-ft [39.6-m] of dense sand resting on bedrock. A mat foundation supported on unsuitable soils improved by jet grouting was selected for the project. Design concepts and selection of the engineering properties of the improved and natural foundation soils are discussed. The results of quality control testing and methods to verify design parameters during construction are presented.INTRODUCTIONNew York City (especially Manhattan) is known for its skyline of high rise structures. The geologic conditions in the New York Metropolitan Area influence the selection of foundations and feasibility of high rise construction as noted by Horvath (2013). These conditions include varying depth and quality of bedrock, multiple glacial events during the Pleistocene Epoch, and the effects of human modifications to the subsurface environment. Clusters of relatively taller buildings are generally located in Lower and Midtown Manhattan where sound crystalline bedrock is at relatively shallow depth beneath the ground surface and shallow foundations rest on the bedrock surface. In recent years the use of more costly high capacity driven piles or drilled caissons and deep basements has enabled the high skyline to spread to other areas."

Jan 1, 2016

By Andrea Zanon

Slitting processes have been used for many years to increase the productivity of smaller diameter deformed bars, without making major investments in the rolling mill. This technology is used mainly for the production of reinforcing bars (7-20 mm diameter), but successful applications exist also for round bar production. The multi-slitting process enables to produce up to 5 bars starting from one billet, thus increasing the productivity of the smaller products. Danieli Morgårdshammar, world leader in the supply of rolling mills for long products, has been a front-runner in slitting technology since its first applications and has recently developed, first in the world, the technology to produce 5X8mm rebar. This process has been recently applied in BRSM steel, a company based in Bangladesh which is a worldwide benchmark for slitting technology performances. This paper presents the necessary modifications which need to be considered when developing a 5-strand slitting project (and multi-strand slitting projects in general), as well as the results obtained at BSRM Steel when the process was implemented in 2016, the first rolling mill in the world rolling 5X8 mm slit rebars.

Oct 30, 2017

By M. P. A. Hames, D. R. Beaumont

INTRODUCTION Legend has it that when Isembard Kingdom Brunel was confronted with the cost and consequences of one of his bridges having failed, he responded cheerfully that the event had saved investors and taxpayers a fortune because it prevented him from repeating the same design at several other locations. To meet the demands of rejuvenating and expanding the transportation system in an era of industrial growth Brunel and his contemporaries introduced bold designs and many innovations. Great advances in design and construction techniques resulted, yet these too had their practical limits as the story tells. In the gold mining industry today we face the same challenge of expansion, yet designers must respond mindful of economic restraints. Is innovation the answer? It has two meanings; to bring in novelties and to make changes. Distinguishing between improvement and novelties, or simply recognizing the benefits and limitations of new ideas over proven technology is part of good design. This paper will illustrate the practical aspects of selecting appropriate solutions to a design problem by examining a variety of examples common throughout the industry. Since a variety of engineering disciplines contribute to the design of a gold processing plant, and each has some old wisdom to impart or new development to boast this paper is divided into the different areas of expertise involved.

Jan 1, 1987

By MattelmSki M

Outokumpu Harjavalta Metals Oy has been producing nickel since 1962, based on conventional flash smelting technology followed by electrowinning of nickel. In the 1980s, a research project was initiated to develop a converterless direct smelting process to produce matte for further refining in the then existing refinery. The process was tested on a pilot plant scale at Outokumpu's research centre in Pori and was found to be viable. The process was named the Direct Outokumpu Nickel Smelting Process or the DON Process. At the turn of the 1990s, Outokumpu studied various options to develop its nickel business and the Harjavalta operations. As a result of this work, the DON Process was further developed to produce two mattes: low iron matte in the flash furnace to be leached in the existing leaching circuit and high iron matte in the electric furnace to be leached in the new leaching circuit. In Harjavalta's case, it was essential and important that the process could use the existing flash furnace and electric furnace without converters.

Jan 1, 1996

By Bernardo Siqueira

This paper presents a unique stirred milling technology, Outotec HIGmill™, a modern, flexible and energy efficient grinding solution for fine and ultra fine grinding being tested in an industrial scale level. The test was performed at an iron ore pellet producing plant in Sweden (for confidentiality reasons, it will be referred to only as “the client”) where a pilot HIGmill™ unit (HIG25) was installed parallel to a conventional regrind circuit to compare its performance to the existing ball mill. By using a continuous test run procedure and evaluating the parameters of F80, P80, mill shaft rotation speed and power drawn it was determined its grinding capabilities, operational flexibility and energy efficiency. Outotec HIGmill™ outperformed the existing ball mill in the plant proving its capabilities to grinding finer, with steeper particle size distribution (PSD) and much higher energy efficiency. The tests performed showed that, with further refining of its operation, it is capable of consistently deliver the required PSD with up to 30% higher grinding efficiency.

Aug 16, 2017

By Nik Sokol, Mike Jaeger, Leo C. Weiman-Benitez

Silicon Valley Clean Water signed a progressive-design-build (PDB) contract with Barnard Bessac Joint Venture (BBJV) to design and construct the Gravity Pipeline tunnel in Redwood City, CA. Owner and Design-Builder teamed with designer Arup to provide a final product: 3.3 miles of 182 in. O.D. precast concrete segmentally lined tunnel with 10 ft. and 11 ft. I.D. Fiberglass Reinforced Polymer Mortar (FRPM) carrier pipe, complete with two FRPM Drop Structures. BBJV and Arup collaborated with SVCW to evaluate alternative design concepts, negotiate an agreeable price and reduce contingencies through a transparent estimating process, and deliver the project ahead of schedule.

Jun 13, 2023

By Klaus Pronold

Once installed rolling mills can look forward to a long life. Around 40% of the 140 conventional hot strip mills presently in operation were built between 1960 and 1970. 17 of the 29 CSP®-plants were commissioned before the year 2000 and have automation platforms that are obsolete and/or have outdated rolling technology. Keeping pace with the market requirements is an ongoing challenge for producers of flat steel. It is a real balancing act keeping production facilities performing at necessary levels, safeguarding the investment and keeping outage periods to a minimum. To overcome these demanding factors and strike the right balance allowing for the production of higher grade steel that meets the current market price the installation of mechanical equipment as well as automation platforms and process technology must meet the latest technology standards. Being discussed in this paper are the different motives for modernizations along with their impact on project handling and commissioning philosophies. Experience gained during recent modernization projects in the field of flat steel rolling relating to Steckel / plate mills or current CSP® modernizations will be shared and demonstrate that each modernization has its own individual solution. Specific strategies are explained to help optimize production, increase plant agility and maximize the return on investment.

Aug 17, 2017

By Edney da Silva Dias, Leticia Fuchs, Walter Coan, Rodrigo Deperon, Eduardo Kuhl, Fernanda Jansen, Micael Leandro

O objetivo deste trabalho é apresentar um projeto desenvolvido para maximizar a taxa de ocupação dos veículos que carregam na ArcelorMittal Vega, por meio da utilização de programação linear combinada com métodos de automação de processos robóticos (RPA - Robotic Process Automation), de modo a atender todas as premissas do modelo de expedição de cargas, tais como: restrições de clientes, capacidade máxima por tipo de veículo e distribuição de volumes para as transportadoras de acordo com as metas acordadas. O uso de ferramentas de otimização e automação, integradas ao ERP (Sistema Integrado de Gestão Empresarial), utilizado pela empresa, permite realizar o processo de programação de transportes em massa, obedecendo multicritérios. A ausência de ferramentas que auxiliem neste processo, impacta diretamente na produtividade, na capacidade intelectual dos recursos alocados, na taxa de ocupação dos veículos, na capacidade de expedição da fábrica e no nível de serviço ao cliente. Visando aumentar a eficiência nos processos, melhorar a taxa de ocupação da capacidade dos veículos e consequentemente a capacidade de expedição, foi implementada a solução para aperfeiçoar o processo de programação de cargas e agregar valor ao negócio quanto a entrega ao cliente final.

Oct 1, 2019

By Knud Sinding

Mining firms are widely criticised for their adverse impacts on the environment. At the same time many firms in the industry devote extensive resources, both financial and managerial, to the reduction or elimination such impacts. Very considerable improvements have been made, although these are sometimes overshadowed by a few high-profile accidents, such as the occasional collapse of a cyanide-containing tailings dam. In parallel, much effort is also directed at projecting a positive environmental image, as witnessed by extensive environmental reporting, both on paper and increasingly through web-platforms. Mining projects today almost invariably involve some form of environmental protection. In industrial countries regulations in this area are extremely stringent, as is enforcement. In less well developed countries, regulation and enforcement may be weaker, but firms are in many cases and for a number of reasons committing themselves to high levels of environmental protection, even if they might get away without doing so. Research in the area of environmental performance of mining firms has so far paid much attention to concepts such as sustainability indicators and the sustainability of individual firms. Given the still raging debates about the appropriate way to determine the degree to which any given firm is sustainable (Welford 1995) as well as the usefulness of what will in the final analysis be a value judgement, anyone on the sidelines of the debate will come back to the fundamental issue, how is knowledge that a particular firm has been judged ?sustainable? going to be made use of. This issue remains unresolved, which may explain the lack of progress in formulating a useful definition of a sustainable firm The question addressed in this paper is not so much about what firms are doing on the ground or in any particular case of environmental protection, but more in the subsequent use of these efforts - and by extension - on the overall direction of corporate environmental strategy. The fundamental problem facing all mining firms is that they cannot easily benefit from unilaterally reducing their environmental impact. The firm can of course avoid liability and keep a variety of stakeholders happy and hence experience lower costs of obtaining the [input] resources they need (in a broad sense, not just minerals), but this represents only part of the opportunities available form pursuing an environmental strategy (Reinhardt 2000). The other part, which may have an enormous potential, involves the concepts of competitor management and product differentiation. The logic of keeping stakeholders happy has been most forcefully argued by Pfeffer and Salanchick (1978) who link the behaviour of firms in all domains to their ability to obtain the resources they need, at a cost that is lower than it would otherwise be (Pfeffer & Salanccik 1978). Several varieties of strategy can be included under this heading, including cost reduction and risk management. The alternative logic is to convince customers that they want to pay more for minerals supplied by mining firm X or directly attributable to mine Y, or by making all mineral users pay more. These two strategies, which may be referred to as product differentiation and competitor management, respectively (Reinhardt 2000) are related to the demand side of mineral supply, whereas cost reduction and risk management are related to the supply side. Mining firms have not pursued the demand side very much, if at all. This is probably due to the extreme difficulty of moving mineral products, bulky and unglamorous as they are, away from their

May 1, 2003

By R. M. Cooper, H. K. Herbert, D. N. Phillips

A study was carried out to determine the effects of adding CaCO3, Fe, Al and CaSi2 to the ladle, rather than to the raw materials, in order to increase the concentration of Ca, Fe and Al in the final product to meet customer specifications at Simcoa's Kemerton plant in Western Australia. LA-ICP-MS, SEM-EDXRA and ICP-AES analysis of samples and controls showed that the technique is suitable for controlling minor element concentrations. Iron was successfully added, while calcium silicide with aluminium proved better than limestone with aluminium for controlling Ca and Al concentrations in the silicon

Jun 19, 1905

By W. A. Parks

Stone that may be applied to purposes of construction is available in nearly all the inhabited parts of Canada, the most important exception being the prairie region, but, even here, the deficiency is overcome in many parts by a wealth of glacial field-stones. In many parts of the country, also, the accessible stone is of a quality so poor that brick is more generally used. There is a great difference, however, between stone that 'may be used' and stone suitable for buildings of a monumental type or even for 'trimmings' on the better class of dwelling in the cities and towns. It is in the latter sense that the expression 'building stone' is commonly used. Thus restricted the term includes varieties of sandstone, limestone, and granite, using the latter word in the custom of the quarryman, not only for the true granite of the geologist but for many other igneous rocks as well. Building stone of high quality grades imperceptibly into stone suitable for monuments, particularly in the case of the granites. The present review will deal with building and monumental stone in this restricted sense and will omit marble, although that material has been used to some extent for building. For instance, the Great West block in Winnipeg is built of marble from British Columbia.

Jan 1, 1925