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By S. I. Vobnout, J. Wm. White, J. P. Olson

"Mine management now recognizes the value of computer-based truck-shovel dispatching in open pit mines. The key tangible benefits are substantial productivity increases with a given fleet of equipment or, alternately, significant reductions in equipment required to meet production quotas. In this paper, the authors review the literature, report on efficient, optimal algorithms for haul truck dispatching in real-time, and briefly discuss methods used by various mines to evaluate productivity improvements over manual methods. Actual results obtained at thirteen mining operations around the world are also presented.IntroductionModular Mining Systems manufactures, installs, and supports its computer-based DISPATCH system at mines worldwide. DISPATCH is a large scale, computer-based mine management system which controls the dispatching of all haul trucks in any open pit mine (Fig. 1). When increased production is important, DISPATCH gets the needed production increase with fewer new or recommissioned trucks. DISPATCH also helps operations meet its blending objectives while minimizing rehandle and maintaining production. Furthermore, DISPATCH includes a powerful, eventdriven simulation subsystem. With the simulator mine management can pose ""what if' situations and see the predicted effect on production"

Jan 1, 1993

By K Komori

Naoshima Smelter and Refinery has treated shredder residue and incinerator fly ash in Japan since 2003. As a highlight, a new incinerating and melting furnace, as well as fly ash washing treatment plant were newly constructed for pre-treatment of shredder residue and fly ash respectively, and the pre-treated materials are ultimately treated in the existing Mitsubishi continuous copper smelting and converting process line. Since wastes such as shredder residue tend to vary in size and in shape, and contain some chlorine, the installation of a new pre-treatment line was required. The combination of the new pre-treatment line with the existing Mitsubishi Continuous Copper Process line has created a highly efficient and environmentally friendly system for recovering and recycling of valuable metals that previously used to be sent to a landfill. This paper reviews the approach that Naoshima took to establish its current recycling business strategy.

Jan 1, 2007

By K. Matsuura, M. Ohno, T. Tokunaga

"Recently, weight saving of automobiles has been strongly required to solve the global environmental problems. Mg alloys are one of the promising candidates as a new material for automobile components. However, the application of the Mg alloys is limited due to their poor corrosion resistance. In the authors’ preliminary study, an Al/Mg/Al clad sheet was fabricated by hot extrusion and subsequent hot forging. The clad sheet exhibited a high corrosion resistance and excellent super plasticity. More specifically, the elongation of the clad sheet was as high as 550%.Importantly, despite that the elongation of Al itself was only 40%without cladding with Mg, the ductility of Al was greatly improved in the form of the clad sheet. In the present study, in order to clarify the mechanism of the superplastic deformation of the Al part in the clad sheet, the microstructure evolution of the Al during the tensile de formation is investigated. The tensile tests were conducted at a temperature of 573 K and at a strain rateof1.0×10-3s-1. The Al exhibited fiber-type texture at the beginning of the tensile deformation, and brass-type texture after the elongation of 50%.INTRODUCTIONMg alloys have been gaining attention because of their excellent properties e.g. light weight, good recyclability and high electromagnetic shielding. However, their practical applications have been limited due to their poor corrosion resistance. In the authors’ previous study, in order to solve this problem, Al coating on Mg alloy by hot extrusion has been proposed, and the Al-coated Mg alloy plate was fabricated(Tokunaga, Matsuura, &Ohno,2012). The plate was hot-rolled and an Al/Mg/Al clad sheet was fabricated. No cracks or debondings were observed at the Al/Mg interface. The sheet exhibited a high corrosion resistance in a comparable level as pure Al. Also, the sheet exhibited a large and uniform elongation of 550%in a tensile test at a temperature of 573 K and at a strain rate of 1.0×10-3s-1without any breakings or debondings of the Al part(Tokunaga, Matsuura, &Ohno,2014).Mg alloys have been known to exhibit a superplastic characteristic when the grain size is small. However, it is known that the pure Al does not generally exhibit the super plasticity. As mentioned above, the Al-coated Mg alloy sheet exhibited 550% of elongation in the authors’ previous study (Tokunagaet al., 2014). However, the pure Al itself showed only 40% of elongation, while the Mg alloy itself exhibited 800% of elongation. Thus, it has been demonstrated that the pure Al was super plastically elongated when it was bonded with the Mg alloy. Generally, deformation mechanism of the super plasticity of the Mg alloy is known as a grain boundary sliding. On the other hand, the mechanism of the superplastic elongation of the pure Al is still unclear. The purpose of the present study is investigation of the deformation behavior of the Al part in the Al/Mg/Al clad sheet during tensile de formation."

Jan 1, 2018

By R. D. Corrans

"Africa is endowed with a number of the world's giant ore deposits which have contributed significantly to the development of their host countries. Mineral exploration has a long history in the continent, but mining on an unprecedented scale took off during the latter part of the 19th century, accompanied by the development of lines of communication and other infrastructure to service the major mining centres.The ""Winds of Change"" which swept Africa in the 19505 and 1960s brought in new styles of government and economic management to a number of regions, often with demise of economic viability and infrastructure. In recent years, with the end of the cold war, collapse of communism and changes in South Africa, new opportunities for mineral exploration are opening up rapidly in Africa. However, due to the large cost, long lead-in time, and high risk of developing new mineral ventures in the continent, it is necessary for the host countries to draft realistic and favorable mineral laws and fiscal codes in order to attract, and not deter, potential mineral investors. There will be an on-going role in mineral exploration throughout Africa for the artisanal miner, the smaller entrepreneurs and mining companies, exploration aid programs funded by the developed countries through African governments, as well as the major mining houses who have the resources to develop larger viable mineral deposits."

Jan 1, 2008

By E. Norton

"Even though the subject of this panel discussion is dust control, rather than dwell on the design aspects of dust collection systems which are well documented in numerous publications, :it was considered more pertinent to the present economics of mining to examine the energy costs involved.At the present time, the facts of shrinking fossil fuel reserves and spiralling fuel costs are being constantly brought to our attention. Industry is being motivated to consider the possibilities of incorporating heat recovery systems in areas where they prove to be economical. Unfortunately, it is not a simple exercise to determine if the installation and operation of heat recovery equipment is feasible and economical. Each process involving heat recovery potential must be thoroughly studied in all aspects.In a paper presented at the 1975 Annual General Meeting of the Canadian Institute of Mining and Metallurgy in Toronto, Ontario, entitled ""The Influence of Energy Conservation on Concentrator Design"", it was stated that the largest single energy consumer in winter is space heating with the largest portion of this supplied to crushing and screening plants. (1) Within the scope of this panel discussion we will study, as one example, a crushing and screening plant using natural gas heat in the province of British Columbia and we will explore the feasibility and economics of installing air-to-air heat recovery equipment."

Jan 1, 1976

By Dirk van Zyl

The world is consuming more and more electronic products every year. This has caused a dangerous explosion in electronic scrap (e-waste) containing toxic chemicals and heavy metals that cannot be disposed of or recycled safely. But this problem can be avoided. We are pressing leading electronic companies to change; to turn back the toxic tide of e-waste. Every year, hundreds of thousands of old computers and mobile phones are dumped in landfills or burned in smelters. Thousands more are exported, often illegally, from the Europe, US, Japan and other industrialized countries, to Asia. There, workers at scrap yards, some of whom are children, are exposed to a cocktail of toxic chemicals and poisons.

May 1, 2008

By L. D. Smith

"Those who submit competing proposals for projects seek to present senior management with complete and fully supported material that will not fail under questioning. Hopefully, misleading notions and omissions will have been minimized and there will have been testing of the assumptions regarding the economic, social and political environments.A capital project evaluation team can do management and itself a service by including a sound approach to the impact of inflation (and its twin problem, interest) on a project and a great disservice with an inappropriate approach to inflation.InflationHandled deftly, inflation can alter a project evaluation to show almost any result the handler desires. It must be a constant source of frustration for design people and cost estimators to spend weeks perfecting the technical aspects of a project in order to minimize costs, only to have all of their efforts set awash in a sea of financial and economic assumptions that submerge all of the detail. In all of this, inflation is perhaps the largest offender, with inflation criteria often being brought to bear at the last minute, almost as an afterthought. Perhaps this tardiness reflects the difficulty of the subject and the belief that senior management will take its own approach to the problems of inflation. Such a belief is unfair to senior management, for it is entitled to not being misled by omission. It is entitled to the full use of the skills of the evaluating team, including reasonable assumptions of the impact of inflation.Working in a consulting context, one has the opportunity to participate in the evaluation of a large number of projects."

Jan 1, 1990

By E. N. Durussel

"The Fox Mine has been producing copper/ zinc ore since 1970 at a rate of approximately one million tons per year, and until 1978all production was derived from longhole open stopes. In June 1978, a trial stope using bighole mining methods was started to eliminate the development of two sublevels between 400 level and surface. The trial proved to be successful, and bighole mining is now an accepted mining method for both stopes and pillars at Fox Mine.When production blasting was started in the first stope, the biggest problem encountered was the production of large amounts of sulphur dioxide gas as a result of secondary sulphide dust explosions. This gas generation resulted in lost production time and caused minor damage to underground installations to the blast level, and to the headframe. Sulphur dioxide generation has been noted in secondary drawpoint blasts and, on rare occasions, in drift rounds.This paper discusses the occurrence of the sulphur blasts and the practices and precautions used to prevent their reoccurrence at Fox Mine.IntroductionThe Fox minesite is located 30 miles southwest of Lynn Lake, Manitoba. With production startup in 1970, Fox Mine is owned and operated by Sherritt Gordon Mines Limited.The Fox orebody occurs as a large lenticular zone of semi-massive sulphides approximately 1,500 feet long and 15 to 100 feet wide running east and west. Dipping 70 degrees to the north, the orebody tends to bottom out at the 3200-foot level and reaches to within 15 feet of surface."

Jan 1, 1981

By D. R. Murray

"A promising long-term solution to uranium tailings reclamation has been the establishment of vegetation directly on the waste material. The soil profiles of areas vegetated for 0, 3, 8 and 10years are characterized as to the extent of soil development . The characteristics are compared with the visually interpreted soil profile. Organic matter content is presently the best analytical judge of soil development. Vegetation procedures have produced a build-up of organic matter in the top 10cm of tailings where natural microbial populations flourish. The CN ratio is high and the profile depth shallow, suggesting the need for additional fertilizer applications.IntroductionThe reduction of surface erosion and improved aesthetics of uranium tailings has been accomplished by the establishment of a vegetative cover. In 1971 research concentrated on developing methods of plant establishment at minimal cost and soil amendments on uranium tailings in Elliot Lake , Ontario. One process of stabilization used on a large scale was direct seeding of grasses and legumes into the tailings which had received only limestone and fertilizer treatments. Fertilizer additions were made for varying lengths of time in subsequent years to maintain the established cover.Maintenance-free vegetation would be possible once a soil profile developed with sufficient nutrient recycle and plant regeneration capabilities(1). Tailings vegetated in 1971, 1973 and 1978 that had received either 3 or 5 years of maintenance fertilizers were examined for soil development profiles. The extent of soil development and the relative effect of time and fertilizer would provide direction on reaching the goal of a self-sustaining cover.This paper is an abridgment of Division Report MRP /MRL 81-126 of the same title(2)."

Jan 1, 1984

By K. Mayhew, A. Lossin, H. Salomon-de-Friedberg

"The proportion of arsenic-bearing copper concentrates that supply the copper industry is on the increase. The current strategy of miners and smelters to blend feeds to reduce average arsenic levels is rapidly becoming unsustainable as more concentrates with even higher arsenic levels enter the marketplace. In addition, the capability of smelters to manage increasing arsenic levels to more stringent and restrictive environmental standards is limited by available process technologies.CESL Cu-As Technology is a viable technical and economic alternative to traditional smelting. It offers the advantage of simultaneous leaching and precipitation of the arsenic in a single processing step while achieving high copper extractions. The process has been piloted in six separate, fully-integrated pilot campaigns for feeds ranging from ~1% to 12% arsenic in concentration. This paper will focus on the behaviour of arsenic in CESL’s leaching/precipitation step and operational factors that influence it, and on the chemical and physical characteristics of the subsequent iron-arsenic residue that represents today’s best available technology from a long-term sustainable (capital/operating costs, metal recovery, safety, environmental) perspective.The examples provided will demonstrate copper extractions approaching 99% and arsenic deportment to residue of 99%. Instantaneous settling rates of the residue were measured at 15+ m/hr. Data from subsequent short and long-term stability testing of the residue confidently support the view that the scorodite-bearing residues from the process will be stable and provide an acceptable arsenic management practice. The technology offers increased revenue and environmental certainty for miners, smelters & refiners to support the development of metallurgically challenged copper-arsenic deposits. Furthermore, results will be presented demonstrating the technology’s ability to successfully incorporate hazardous arsenic containing smelter by-products such as dust into the process feed and simultaneously extract copper value while fixing the arsenic in a stable residue."

Jan 1, 2016

By A. Kraly, M. Complojer, P. Paschen, K. Gamweger, H. Antrekowitsch

Increasing quality of aluminium alloys and continuous optimization of the production process leads to an improvement of the gas purging systems. The application of porous plugs for the treatment of liquid aluminum is nowadays not widely used in the aluminium industry especially in Europe. The Department of Nonferrous Metallurgy and the Christian Doppler Laboratory of Secondary Metallurgy of Nonferrous Metals intensified the research and development of refining and alloying processes by gas treatment during the last years. CFD-modeling supports these experiments, which should lead to lower hydrogen content, lower suspended particles and a better distribution of alloying elements in the melt. Different parameters such as temperature, bubble size, gas amount and which kind of gas is used influence the quality of the products.

Jan 1, 2006

By LeRoy A. Thorssen

The use of lightweight aggregate as a constituent of concrete is not a recent development. Pumice was used by the early Romans, in pozzolana cement concretes, in the construction of many of their works. However, the recent development of manufactured lightweight aggregates, such as the expanded shales, vermiculite and perlite, has created a possible use for a whole new group of Portland cement concretes. Concrete can now be produced with unit weights ranging from 30 to 150 pounds per cubic foot and with various insulating, fireproofing, acoustical and structural properties. The tonnage of such materials being used has increased considerably in each of the past ten years, and can be expected to increase for the next several years as availability of the aggregates becomes more widespread and the properties of such concretes become more thoroughly investigated and more generally known. LIGHTWEIGHT aggregates of many types have become avail-able to the construction industry in most localities on this continent

Jan 1, 1963

By Tom Brady

A major focus of ground control research presently being conducted by the Spokane Research Laboratory of the National Institute for Occupational Safety and Health (NIOSH) is to incorporate data on weak rock masses into existing design relationships, with an emphasis on updating the span design curve for manned entries and the overbreak curve for longhole entries. Both curves were originally developed at the University of British Columbia, Vancouver, BC. The original database has been augmented by information from mines throughout the United States, Canada, Australia, and Europe. The common factor in all these mines is the presence of a weak back and/or walls. In most cases, the ore zone is the weakest rock unit and must be stabilized so that the mineral-bearing rock can be extracted safety. The current NIOSH research attempts to provide rock mechanics tools to assist a mine operator in making economic decisions that will also ensure a safe working environment. This paper documents the North American database.

May 1, 2006

By G. Vibert Douglas

NICKEL minerals are known in New Brunswick but have never been reported from Nova Scotia. The attention of the writers was drawn to an occurrence of pyrrhotite, reported to carry nickel, at the Second Gold brook, Middle river, Cape Breton. The purpose of this paper is to record the occurrence and give an account of the general geological association. In a later paper it may be possible to give greater details? than are available at present. GEOLOGY The area lies at the edge of a plateau of Precambrian rocks which forms the panhandle of Cape Breton island. This plateau has a general elevation of 1,200 feet. Middle river, with its tributaries, the First, Second, and Third Gold brooks drains the area. The lower country to east and southeast of the plateau is underlain by lower Carboniferous sediments. The rocks of the plateau are presumably of Precambrian age but have never been definitely correlated with the Gold-Bearing Series of the mainland. ?There i:s; however, some resemblance, although they have apparently been more intensely mountain-built. They are essentially fine grained, sheared quartzites and slates . The general strike is east and west, with a north dip of 45° to 55°. There are smalllocal drag-folds in the area. The only igneous rock in the immediate vicinity is an intrusive pink porphyry. It has small phenocrysts of quartz and feldspar. It has intruded the sediments generally along the structural planes, but in places crosses the structure . Its intrusive character is further proved by the fact that it contains xenoliths of the quartzite.

Jan 1, 1937

By N. Bartie

Realising the circular economy (CE) is faced with some significant challenges. Process metallurgy and its infrastructure play key roles at the heart of making the CE work. Therefore, the enabling role of process metallurgy within the CE will be central to the discussion in this paper, touching among others on product and system design as well as the key metallurgical and other process fundamentals that need to be investigated and understood to make the CE a reality. The central role of materials and its processing will be discussed in an integrated circular cities perspective. A key focus will be a discussion on designing a resilient “Smart Materials Grid” using and innovating metallurgical process engineering tools, which will manage the flows through Sustainable Circular Cities. The discussion will be using copper as leitmotiv of the discussion i.e. from copper ore, to metal, to complex products, recycling, product design and simulation and its impact. INTRODUCTION The transformation of our economies from linear to circular models in which waste materials become resources is the focus of the Circular Economy (CE) paradigm. Its important intentions: to take control of the damage we have been doing to the planet to ensure its livability and the welfare of future generations. This can only be achieved through careful utilisation of human, natural and economic resources. The concept is derived from several others (Beaulieu et al., 2015), of which Cradle-to-Cradle, Extended Producer Responsibility (EPR), Industrial Ecology, and Life Cycle Thinking are just a few. Other relevant concepts include resource efficiency (RE), design-for-recycling (DfR), and various others discussed by Blomsma and Brennan (2017) and Homrich et al. (2018), as well as various R-hierarchies e.g. Reduce, Reuse, Recycle (3R). However, does society comprehend these concepts, the actors and actions that influence them and how they interact? Do we know the limits of CE? Does society understand the key role of Copper and other metals to rendering the CE operable? True life cycle and systems thinking, focussed on simulation-based, process and metallurgical design are required to answer these questions. Lieder and Rashid (2016) identify nine widely-varying fields that study the concept ranging from sustainability sciences and engineering to economics, business, law, and social sciences. Overlap between questions addressed highlights the need for interdisciplinary collaboration (Nanz et al., 2017) in the assessment of the current status, and further steps needed to transform to CE. This doesn’t apply just in academia, but also in industry where concrete implementation of CE needs to occur at multiple levels, thus necessitating cooperation between government, civil society and other stakeholders (Beaulieu et al., 2015).

Jan 1, 2019

By R. W. Thompkins

"PREFACEPart 1 of this paper, published in the September issue, covered the occurrence of uranium, radiation from uranium ores, the uranium series, radioactive theory, radioactive equilibrium and application to the radon series, the working level, the theory of emanation and diffusion, transport by thermal diffusion of radon emanating from porous rocks, and definitions.The October issue carried Part 2, which dealt with radiation theory applied to uranium ores, other radon migration factors, factors affecting the radon gas release rate, the measurement of radon gas emanation rates, the tunnel concept, variation of emanation rate with grade and estimating radioactivity from grade analysis.Part 3, in this issue, concludes the series by discussing the techniques for controlling radiation and providing some example calculations.17.0. Techniques for Controlling Radiation17.1. Altering the Factors In the Diffusion EquationIt has been noted that radon gas emanates from the surfaces of exposed ore to the mine atmosphere. The diffusion laws establish the rate of this flow. The fundamental relationship is that the rate of flow (J) is a function of the pore concentration and the distance from the surface. It is expressed as: []If any of these terms is varied, either naturally or artificially, the rate of gas emanation will be altered.Altering the Diffusion CoefficientThe literature describes many ways to lower the radon gas emanation rates which are dependent on changing the diffusion coefficient:1. A layer of ice on top of a tailings dam or on a soil.2. Humid clayey materials and swamped soils over a radon source."

Jan 1, 1982

By A. Putz, F. Vincent, A. R. Laplante

"This paper briefly reviews some of the gravity research done at McGill University and current Canadian operating practices, with emphasis on results of interest for operators. The following topics are addressed: security, economics, predicting recovery, circuit optimization, unit selection and final upgrading. Emphasis is placed on the Knelson Concentrator.The topic of security and economics are addressed jointly, in terms of the place of the gravity circuit in the mill flowsheet. Actual plant experience is drawn upon to identify potential problems and actual solutions.Predicting primary recovery is linked with a characterization of the ore, the choice of a circuit, and the fraction of the bleed used. Factors such as feed preparation, preliminary upgrading, fraction of recycle treated, ability to recover fines and location of the bleed are discussed.Final upgrading is achieved almost only by tabling and smelting. This can lead to fine gold recovery problems when more effective units are used upstream. Alternatives are discussed.IntroductionResearch on gold recovery by gravity over the past eight years has associated McGill University with a number of gold producers. This paper attempts to review the information gathered from a practical perspective. Some of the information was generated in McGill University's labs, some gathered at plant site, and some was shared by operators."

Jan 1, 1994

By L. Tang

A seismic monitoring system was installed in 2005 at Dongguashan Copper Mine, the deepest metal mine in China. Based on the seismic events monitored in situ, the possibility of rockburst prediction and prevention is investigated in this paper. The characteristics of space-timeintensity of mining-induced seismicity and the seismic response to mining are studied in detail using the seismic data in Dongguashan Mine. A conceptual model and a criterion of assessment of hazard seismic nucleation are proposed for Dongguashan Mine. In this model, the mine seismic stiffness method is adopted for rockburst prediction within the framework of the unstable failure theory. To analyze rock failure cases in Donggauashan Mine, the rate of the ratio of stiffness of rock in nucleation area to its surrounding area is proposed as a criterion for rockburst prediction.

May 1, 2009

By C. Tan, A. Putz, P. Lacombe, R. Kemp, M. Kaya, B. J. Huls, A. R. Laplante

"This paper concentrates on the four recent plant trials/ applications of froth washing. Results showed that improved metallurgical performance can be achieved with wash water. Increased froth cleaning yielded better upgrading, and some cases slightly improved recovery. Froth sampling and salt tracer tests supported the findings of froth washing tests.At Falconbridge, Ni grade increased from l.47% to 2.15% and recovery from 85% to 87%. At Eastmaque, final Au grade increased from 2.3 to 2.7 oz/st at a slightly higher recovery. At Les Mines Selbaie, Cu grade increased from 24.5% to 25.S% and Zn grade from 54.5% to 56.l%. At Zinc Corp. of America, average Zn grade increased from 55% to 56. 8% at the same recovery for a 45-day period. A number of plants in Canada and the United States have evaluated and/or now practicing froth washing. Wash water has now proved itself in some plants over several months of operation.INTRODUCTIONFroth washing in mechanical flotation cells offers a number of metallurgical (i. e. increased grades and/or recoveries) and economical (i.e. decreased transportation and smelting & refining costs) benefits. Fundamental development work in laboratory and pilot scales performed at McGill yielded encouraging results. (Kaya and Laplante, 1988a and 1989a). Since laboratory and pilot flotation performance can differ from full-scale due to differences in hydrodynamics, kinetics, and froth characteristics (e.g. stability, loading etc.), plant trials were essential to prove the viability of this technology."

Jan 1, 1990

By R. Tipman

"In 25 years, processing of tar sand progressed from two small pilot plants to two major commercial operations owned by Syncrude and Suncor. These plants mine tar sand and extract the bitumen which is then converted into a synthetic crude oil. Considerable research on extraction of bitumen from tar sand has been undertaken by these two companies as well as other major oil producing companies, private individuals, universities and the federal and provincial governments. These studies have produced a number of alternate processing schemes which have yet to be commercialized. The producing companies are focusing their efforts on achieving increased processing efficiency, which includes improved bitumen recovery, reduced unit cost, energy conservation, and equipment reliability. In this review, the Syncrude process and examples of new process developments will be briefly described. IntroductionTwenty-five years ago, tar sand processing was limited to two pilot plants owned by Cities Service Athabasca Ltd., and Great Canadian Oil Sands. Earnest Manning was Premier of Alberta and was inviting proposals for the construction of a commercial tar sands plant. The invitations called for a much larger operation than those which had been undertaken in the past. All of the previous attempts at commercial operations up to 1960's had failed, largely because of a poor technical understanding of the process requirements, lack of suitable equipment, and lack of adequate capital. The previous record was not good. The pending new large scale plant was based on improved but not proven technology and equipment, which were developed from the pilot plant studies. In addition, the surplus of conventional oil in Alberta and low world oil prices were factors reducing the need for such a plant."

Jan 1, 1987