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By M. Muinonen, R. Pandher

Royal Nickel Corporation is developing the Dumont Nickel Project, a large nickel sulphide deposit located near the town of Amos, Québec. The nickel occurs as pentlandite, heazlewoodite, and awaruite. The relatively low grade ore can be processed to a very high grade nickel concentrate, containing 29% Ni. The absence of copper and precious metals in the ore renders this concentrate amenable to processing by dead roasting in a fluid-bed roaster and smelting in an electric furnace to produce ferronickel for sale to stainless steel producers. Laboratory test work and conceptual engineering design was completed to demonstrate the amenability of Dumont concentrate to produce ferro-nickel.

Jan 1, 2015

By John W. Korczak

The use of geological and grade block models has been standard practice in mine design for many years now, with a wide range of software available for creation and analysis. Although geotechnical parameters are of vital importance to mine planning there is very little in the way of commercially available systems for integrating geotechnical data into the mine planning and design process. Sirovision is a new technology developed by the CSIRO (Commonwealth Scientific and Industrial Research Organization) in Australia for automated, safe and accurate 3D mapping of geological and geotechnical features. Datamine has integrated this capability into its product range so that Sirovision has become an integral part of the day-to-day mapping, mine geology and geological / geotechnical modeling in both open pit and underground mine environments. This is the first integrated underground application of Sirovision from Datamine collaboration with Xstrata Nickel at the Nickel Rim South Project. This paper discusses the role of Sirovision in collecting the raw data required for geological and geotechnical analysis and the interpretation in a quick, safe, auditable and reproducible manner.

May 1, 2009

By C. I. Garcia, G. Zhou, W. Gao, A. J. DeArdo

The development of X-100 and X-120 linepipe steels was investigated using a series of low-carbon Mo-Nb-B steels. The laboratory steels were vacuum melted and processed using advanced thermomechanical processing (TMP) philosophies. Prior to the laboratory hot-rolling experiments, the grain coarsening temperature, the conventional T95 and T5 start-stop recrystallization temperatures and the transformation behavior of y were studied using a computer-controlled high temperature deformation MTS-458 and a Theta-IV High Speed dilatometer systems. The results from these experiments provided the guidelines for the design of the laboratory hot-rolling TMP processing experiments. The mechanical properties of the experimental steels showed yield strengths in the range 700-850 MPa and CVN impact properties of over 80 J at -20°C. The best balance of mechanical properties was obtained by using CCR+DQ+Tempering treatments. The major microstructural features responsible for the observed mechanical properties in order of importance were: a) substructural refinement associated with lower bainite, b) dislocation strengthening, c) fine recrystallized ferrite, and d) small amounts of retained austenite. Fine Nb(C,N) precipitates formed in ferrite were observed, however their contribution to the strength was minimum. Most of the Nb(C,N) precipitation took place in austenite. This precipitation was used to exert microstructural control of austenite during hot rolling. The physical metallurgy and optimum TMP to achieve the mechanical properties are detailed in this paper.

Jan 1, 2005

By David Burchell

Duckbill mining is probably the simplest method of loading coal mechanically at the face in underground mines. It is a means of reducing the amount of physical labour required to produce a ton of coal. In effect, it is merely shaker conveyor mining brought up to date with the addition of a self-loading head or 'duckbill' on the end of the conveyor line. Any mechanical device used to load coal is a means of supplanting the human muscles as the medium for getting the coal off the floor into the transportation equipment. There can be no argument with the conclusion that a man can lift so much and no more. He can load more tons of coal on a low conveyor, because the lift is less, than he can in a pit car two, three, or even four feet high. Thus it follows that, if the lifting operation is entirely eliminated, the man should be able to produce even more coal. A mechanical operation is essentially a multiplication of physical strength. Although there are various ways in which coal can be loaded at the face by mechanical means, there is, perhaps, none more adaptable than shakers equipped with duckbills. This is particularly true for thin seams and in mines having heavy, tender top conditions which require close timbering. However, as we are discussing duckbill mining, we will make no further reference to any other type of equipment. The first, and to date the only, mine in eastern Canada to adopt a system of mechanical loading at the face is the Franklin mine of the Bras d'Or Coal Company, Ltd., at Bras d'Or, N.S. An experimental Goodman shaker conveyor with a self-loading head, or duckbill, was installed in this mine in 1940. Since that time other units have been placed in operation so that, today, this mine is completely mechanized. The method of operation 1s room-and-pillar. The operation is carried on in a 42-in. seam, which lies 420 feet beneath the Sydney Main or Harbour seam in the Sydney Mines basin. The slopes bear N.25 30'E., dip 10 per cent seaward, and are about 6,000 feet in length. The physical conditions of this seam do not make it particularly adaptable for complete mechanization as it contains a large amount of foreign material, such as clay intrusions or wash-outs and iron pyrites. These clay intrusions, known locally as 'troubles', vary in thickness from a few inches to as thick as eighteen feet and usually replace the coal to the full height of the seam.

Jan 1, 1947

By Franz Simon

Conventional fine gold electrolytes for barrel applications working electrolytically actually permit significant precious metal savings by corresponding optimizations but the most gold is still deposited on areas of the components where it is not absolutely essential for the desired bonding and soldering applications, i.e. in high current density areas. Therefore an electrolyte working electrolessly has been developed which inevitably leads to a much more uniform thickness distribution since in an electroless process there are no areas favoured by metal deposition and current distribution. The new electrolyte will be presented and its performance will be compared with conventional electrolytes as regards thickness distribution. The potential gold savings will be discussed.

Oct 1, 2003

By A. Ignatow

"A review is made of some of the principal factors and conditions that are, and will be, important to the over-all market climate for asbestos fibre and for the future of Canada's asbestos industry: - health hazard associated with asbestos exposure;- uncertain international regulatory environment for continued asbestos use;- adverse public reaction to asbestos;- product liability/litigation costs (U.S.A. primarily);- promotion of substitution by governments and asbestos user industries; and- minimal product and market development efforts by asbestos producing and consuming industries.In addition, Canadian producers, who export some 95 per cent of their production, face additional constraints:- dramatically reduced integration with asbestos-consuming industries;- 60 per cent of exports to most rapidly declining markets (U.S.A., Europe);- increased competition from offshore producers favourably located to growth markets in developing countries;- increasing production costs;- a strong dollar;- disadvantageous freight rates; and- loss of price leadership and price erosion.Future market trends, as well as prospects for Canada's asbestos industry, will be projected in this paper.Economic FactorsTable 1 presents asbestos fibre production in all countries for the period 1980-82. In certain instances, e.g. U.S.S.R. and China, these are capacity estimates as production statistics are not officially published. The U.S.S.R, by far, is the world's largest producer accounting for some 50 per cent of world production, though most production is consumed internally or by COMECON countries. It is estimated that some 700 plants produce asbestos-containing products within the U.S.S.R.Canada accounts for some 25 per cent of world production though it ranks first in world trade. Other important producers are South Africa Zimbabwe, Brazil and Italy. Since 1979, Canada's asbestos mining industry has experienced a dramatic drop in production and exports of asbestos fibre, as demonstrated in Table 2."

Jan 1, 1985

By Gerry Doeksen

The paper deals with three case studies: (a) the handling of wet concentrates (5 to 8 per cent moisture) through feed bins; (b) the handling of the same product in rail cars; and (c) the handling of dry concentrates (less than 0.5 per cent moisture) through feed bins. In each case, the paper discusses the problems of rat-holing. In each of cases (a) and (c), there is a discussion on the consequent extreme variations of feed rates coming from the feeders, making automation of process control difficult to impossible. Currently available bin-flow theory and flow property tests are used as aids in redesigning the bins. The paper concludes with illustrations of the final results after the redesigned hoppers were installed and tested. There is also a discussion on the advantages of the new mass-flow bins on adjacent feeder performance.

Jan 1, 1970

By R. B. Nourse, S. F. Gwynn-Jones, S. Nikolic, M. L. Bakker, I. McDougall, H. Joubert

"Tenova Pyromet’s core furnace knowhow and expertise has been built within the ferroalloy and nickel/platinum group metal (PGM) industries with the supply of electric furnaces for a number of nickel/PGM operators, including Eastplats, Lonmin, and Anglo-Platinum in South Africa, Mineraçào Serra Da Fortaleza in Brazil, and Norilsk Nickel in Russia. Tenova Pyromet has also supplied the electrode columns and associated electrode equipment – the heart of the electric furnace technology – for cobalt recovery in furnaces in Zambia and the Democratic Republic of the Congo. The quantity and size of projects undertaken by Tenova Pyromet has provided the opportunity to continuously improve furnace designs and the scope of supply, culminating in the most recent nickel/PGM project currently under construction at Northam Platinum. Through this innovative culture, the Tenova Pyromet Base Metals Initiative was formed in 2015 to develop the Novasmelt™ Furnace; a next generation optimised Top Submerged Lance (TSL) furnace design. The combination of Tenova Pyromet’s advanced Novasmelt™ product with our industry leading electric furnace technology are discussed with reference to applications for nickel and cobalt production. Flowsheet arrangements are compared summarising potential capital savings, operating requirements and achievement of downstream product quality.INTRODUCTION Tenova Pyromet is a leading player in the field of smelting technology development and equipment supply. Tenova Pyromet is the result of the union of three furnace suppliers under the Tenova banner: Techint Technologies (Tagliaferri), Core Furnace Systems Corp (Lectromelt) and Pyromet Technologies. The furnace experience of the combined groups dates back over a century with the earliest Lectromelt going into production in the early 1900s. Throughout the modern era, Tenova Pyromet has developed a reputation for providing dependable innovative smelting technology, high quality equipment and sound project execution to a worldwide client base with customer plants operating in Europe, Southern Africa, North America, South America, Russia, Kazakhstan, the Middle East, South Korea, and India. Tenova Pyromet’s core knowledge and expertise was developed in the South African ferroalloy, base metals, and platinum group metals (PGM) smelting industries. Tenova Pyromet has spent considerable effort on development and has contributed significantly to improve the state of the smelting industry. Tenova Pyromet’s electrode columns have become widely renowned and are now providing significant benefits, especially in increased furnace availability, to many smelting furnace operators. The electrode column is the heart of the furnace as it delivers a controlled amount of electrical energy, at an optimum depth in the burden/bath, to the smelting process. Every furnace is custom designed to the specific operating range and optimal operating point of that furnace and process"

Jan 1, 2017

By J. Wong, M. G. Lipsett, L. K. Daneshmend

"Current trends of increased size, complexity, and automation of surface mining equipment necessitate more comprehensive and objective techniques for equipment comparison and selection. The field of reliability analysis provides tools to generate quantitative bases for maintenance and reliability aspects of such comparisons. Results from statistical analyses of failure and repair time data are used to perform the comparison. A case study is presented which analyzes five machines of two different technologies and three different designs.IntroductionThe surface mining industry is currently faced with a rapid evolution in production equipment. The more obvious trend in this evolution is the steady introduction of even larger machines. Parallel, and complementary, to this increase in size is the introduction or adaptation of new technologies. Together, these two trends result in new surface mining equipment designs; these designs are often more complex and may feature technologies that have yet to be proven for the application or at the scale they are now fielded.The prospect of significant automation of open pit equipment is also bound to add complexity to future equipment designs. Semi-automated features, such as drilling controllers (Aquila, 2000), have already been commercialized. Fully autonomous haul trucks have been demonstrated in open pit mines (Jackson and Zoschke, 2000). Design concepts for comprehensive teleoperation of open pit operations have been formulated (Lipsett, 1998).With this rapid availability and deployment of new technology and equipment, managers and maintainers are faced with a multitude of decisions regarding what equipment to acquire and what maintenance strategies to implement. In light of this evolution in mining equipment, it is necessary to develop better methods for making equipment management decisions (Dessureault et al., 1999; Paraszczak, 1999). The incentive for development of such techniques is that a large portion of an open pit mine’s operating cost is maintenance related, as shown in Table 1."

Jan 1, 2000

By J H. Dressel, J. E. Williams

This paper presents a brief review of what coal gasification is, procedures that are available today and processes that may be available in the future. Examples are given as to how the process might be used in power plant applications, the effect on pollution level and power costs, and some thoughts on the added burden that might be placed on mining and coal preparation.

Jan 1, 1973

By Ian R. Morrison

"Abstract - The Izok Zn-Cu-Pb-Ag volcanogenic massive sulfide deposit is located 265 km south of Kugluktuk (Coppermine), Nunavut Territory, Canada, in the west-central Slave structural province. The Izok deposit is owned 100% by Inmet Mining Corporation and represents one of the largest undeveloped zinc-copper resources in North America. The Izok deposit is hosted within and near the top of a thick sequence of predominantly felsic pyroclastic rocks of late Archean age. The hanging-wall stratigraphy includes additional felsic volcaniclastic rocks, andesitic and basaltic flows, thin sulfide-rich iron formations, and turbiditic sedimentary rocks. The felsic volcanic rocks are intruded by intermediate dikes and sills, followed by gabbroic dikes and sills. Both intrusive suites are interpreted to be volcanic feeders to the overlying flows. All lithologies are subsequently cut by younger, irregular, granitic pegmatite and diabase dikes. The volcanic and sedimentary rocks are regionally metamorphosed to pyroxene hornfels grade. The massive sulfides occur within a large (kilometer-scale) Na-depleted sericitic alteration zone. The immediate footwall and hanging-wall rocks to the deposit are characterized by zones of muscovite- biotite-sillimanite, lesser chlorite-biotite-cordierite, and locally intense silicification and sodium metasomatism. All lithologies have been affected by younger Ca-metasomatism. As currently defined, the Izok deposit comprises a cluster of five complexly zoned composite lenses: the Northwest, North, Central West, Central East, and Inukshuk lenses. The first four lenses are amenable to open-pit mining, whereas the Inukshuk lens will require underground development. The total indicated mineral resource presently stands at 16.5 million tonnes with a grade of 2.2% Cu, 11.4% Zn, 1.1% Pb, and 60 g/t Ag. Inmet Mining Corporation is presently reviewing the economic feasibility of developing the property."

Jan 1, 2004

By M. Askari, A. Ahmadi

"This study was conducted to establish the possible application of bioleaching in the pilot scale to recover valuable metals from the sulfidic tailings of Golgohar Iron Mine (Kerman, Iran). Using bioleaching processes, solvent extraction and sulfide precipitation recovery of valuable metals including, copper, cobalt and nickel from the tailing was investigated. The results showed that the optimum pH and temperature conditions relative to the bioleaching step was 1.5 and 45°C. The extraction of the metals from the low grade polymetal resource with complex mineralogy is very important from economic, environmental and technical point of views. Moreover, the proposed method has some advantages from energy saving, tailing management and creating added value from waste materials aspects.INTRODUCTION The growing demand for base metals and strategic such as: copper, nickel and cobalt as well as high-grade resource depletion has caused them, the mining industry to extract metals from low-grade resources and driven by complex mineralogy (Xie et al., 2005). Economic extraction of metals with low grade sources requires low-cost and efficient processing methods. A source with enormous potential for metals in future, secondary sources, such as: tailings mineral industries which the lack of appropriate technology and the high cost of processing weren't recoverable with previous procedures in the past. But it is possible that with develop new and efficient technologies have the economic exploitation ability. Recovery of metals from tailings resources is very important not only in terms of precious metals but also in terms of reducing environmental problems (due to heavy metals). The metals of copper, nickel and cobalt are mainly like sulfide compounds in the nature, usually for their recovery, first they make ore with flotation method to obtain the sulfide concentrate that containing valuable metals. then for the metal production, it will be melt and purification. Due to the environmental aspects, technical problems in the recovery of base metals from low grade ore and mixes, the presence of small reserves, in the past three decades they pay much attention to the use of hydrometallurgical processes for the recovery of base metals from these resources. These processes are classified according to the solver agent to leaching sulfates, chlorides, nitrates and amines (Hackl, 1995). Early, chloride leaching under oxidation condition in acidic or alkaline solutions was recognized the best process to produce sulfide concentrates. But then the basic processes sulfates was considered as the superior process because of being easier, a better understanding of the chemistry of leaching and recovery of base metals, especially copper from the environment easier sulfate solution with an organic solvent extraction and electro winning. The bioleaching is shown its ability on a commercial scale of low-grade sulfide minerals and ore that because of environmental reasons, the possibility of melting is not possible to them. The existing industrial base factories are based on primarily on the bioleaching and pressure leaching and recovery of cathode copper sulfate solution by extraction with organic solvents (SX) and electrowinning (EW) (Wang, 2005). Preliminary analysis has shown that valuable elements such as copper, nickel and cobalt are in the float flotation unit. Hence the plan to extract these metals from the wet tailing stream has been done."

Jan 1, 2017

By Zoë Mullard

Just as a mine has a lifecycle, employees working within the mining sector also make several transitions throughout their career, from initial recruitment to retirement from the industry. Throughout the employment lifecycle, employees bring skills and knowledge that significantly contribute to the global economy. These skills are developed through education, professional training, coaching and through hands-on experience. Despite the current economic conditions and the demand for minerals, the mining industry is facing a substantial skills shortage due to the disparity between the number of new workers entering the mining industry and a largely ?graying workforce?. Although educational programs continue to evolve to attract people with a wide range of skills, the diversity of jobs and the strains of working in remote mining operations continue to present challenges for recruitment and retention of employees. This gap also presents challenges around knowledge transfer at a corporate and mine-site level; employers will require cultural and techno-sociological approaches to ease through these transitions. At the same time, there has been an explosion of social media tools that facilitate information sharing, cross-organizational collaboration, distance learning and knowledge capture. These tools have become increasingly popular in the last few years and their applications vary widely. The mining sector has started to adopt these tools for a number of purposes, including opportunities to harness social media to enhance human resources interactions, outreach and oversight. This paper will outline several case studies that explore leading practices for how the application of new media can assist organizations and individuals as they progress through their careers. This paper will illustrate how new social media communication technologies can be used to increase employee engagement and build organizational capacity in the mining industry. The paper will also include strategies for how to implement social media to enhance human resources applications and will cover ideas for monitoring and evaluation.

Aug 1, 2013

By Chris M. Healey

"Abstract- The Jasper Gold mine in northern Saskatchewan produced a total mill feed of 140 127 tonnes at an average grade of 19.0 g/t Au. Both diamond drilling and chip samples from under­ ground workings returned extremely high values, up to 12 851 g/t (375 oz/I) Au over 0.10 meter from a chip sample. In the presence of such extremely high grades, the accurate estimation of reserves is a major problem.ln the first part of this study, production data from the mine were used to evaluate the results of a variety of reserve estimation techniques in this environment. In two out of three cases studied, indicator kriging with assays cut to 342.9 g/t (10 oz/I) gave extremely good results. In the third case, however , indicator kriging gave unacceptable results. Instead, lognormal kriging of uncut data gave the best results.Secondly, from the same database, a number of drill-hole spacings were simulated, and reserves estimated from the simulations. As may be expected, the results of this analysis show increasingly better results with tighter drill-hole spacing. However, even with a 5 m by 5 m spacing the variation from actual grade was quite large. This is not a systematic under- or over-estimation of grade, rather a random scatter of results .The results of this study show very clearly the problems of deriving good estimates of reserves when extremely high-grade samples are encountered. There is a high degree of randomness to this database, so reserve estimation in this situation will remain a high-risk operation."

Jan 1, 1993

By B. A. Strathdee

An arsenical ore containing both pyrite and arsenopyrite was heated to a temperature at which decomposition and distillation took place. The condensate consisted of metallic arsenic and arsenic disulphide, although the analysis of the ore showed that volatile arsenic and sulphur were present in proportion to produce a condensate of arsenic trisulphide and sulphur. Distillation tests on the mineral arsenopyrite also produced a condensate of metallic arsenic and arsenic disulphide. This arsenic sulphide gave a distinct x-ray diffraction pattern which was not listed in the A.S.T.M. data file. This same sulphide can be produced by heating a mixture of arsenic and sulphur in vacuo. Its chemical analysis corresponds to As2S2. The dissociation pressures of arsenopyrite and the vapour pressures of arsenic disulphide and arsenic metal were measured, using a quartz "spoon" gauge. The dissociation pressures of arsenopyrite were compared with the published data for the dissociation pressures of pyrite to account

Jan 1, 1961

By P. L. Li, B. X. Song, C. H. Wang, T. Wang, Z. Hu

"The treatment of an oxidized copper-gold ore by stage cyanide addition was investigated. For cyanidation, free cyanide ion concentration can be an indicator of whether there is copper dissolved in cyanide solution, and maintaining the free cyanide ion concentration lower than 1.0 g/L could be an effective way to prevent copper dissolution and reduce cyanide consumption. For that purpose, stage cyanide addition was introduced to control free cyanide ion concentration within the range from 0.8 to 1.0 g/L. Cyanidation tests results indicate that gold extraction was still acceptable at reduced cyanide consumption with a lower copper extraction. Based on the experimental study, industry application works at Beiya concentrator of Yunnan province, China were successfully conducted. When the raw ore contains 2.95 ppm Au and 0.75% Cu, by stage cyanide addition method, the gold extraction was still 93% at reduced cyanide consumption of 2135 g/t, which was only half of one addition method, and the copper extraction dropped to only 5%, which indicated that dissolution was prevented for almost 75% of the malachites.INTRODUCTIONCyanide with its competency to form a strong complex with gold, is the most preferable lixiviant for gold leaching. However, cyanidation is not inherently a selective process since many other minerals present in the ore are also readily soluble, especially the copper minerals. Muir (2011) reported that every 1% reactive copper present in the ore consumes about 30 kg/t NaCN, which can have detrimental effects on the process efficiency and economics due to high cyanide consumption, reduced gold leach rates and poor gold recovery."

Jan 1, 2016

By J. D. T. Steyl

Anglo American Corporation and the University of British Columbia have developed a medium-temperature oxygen pressure leaching process for the extraction of copper from chalcopyrite concentrates in an acid-sulphate system (AAC/UBC process). Leaching is performed at 150°C and surfactants are added to disperse molten elemental sulphur from the unreacted sulphide surface to prevent liquid sulphur occlusion. Copper extractions of over 95% and elemental sulphur yields of around 60% were observed over a 2-hour average residence time in a continuous pilot autoclave. Sporadic blockages occurring under continuous conditions were found to be caused by the accumulation of molten elemental sulphur mixed with unreacted sulphide mineral. A batch programme of experimentation was undertaken to establish the reason for this phenomenon. Batch experiments were conducted at low pulp densities on concentrate samples with narrow size distributions and at similar solution compositions to those experienced in the pilot autoclave. The overall rate of chalcopyrite oxidation was shown, under approximately constant solution composition, to be a strong function of the total available mineral surface area. Initial copper extraction rates followed the shrinking particle kinetic model under intrinsic surface control. Deviation from shrinking particle kinetics was however observed after a certain oxidation time. Secondary electron images identified small (typically less than 20 µm) sulphur conglomerates at the point of deviation, which 'collected' unreacted chalcopyrite mineral particles and lowered the total mineral surface area available for oxidation. These sulphur clusters are thought to be the precursor for blockages experienced in the continuous pilot autoclave. These results emphasised the importance of fine grinding (P80 5-20 µm) and suggest that shorter residence times may minimise the formation of sulphur conglomerates in a continuous autoclave operating at medium temperature.

Jan 1, 2004

By W. A. Roliff

The renewed interest of the past few years in the Appalachian and Michigan oil provinces has not, as yet, created any marked increase in activity in Southwestern Ontario. During 1960 development drilling in-creased somewhat over 1959, but exploratory drilling decreased slightly. More attention was devoted to the deeper horizons, but lake drilling de-creased considerably. Oil production reached a new peak and gas production increased slightly. During 1960 an interesting oil and gas discovery was made in the Cambrian and gas discoveries six miles off-shore in the eastern part of Lake Erie were made in the Clinton-Cataract zone of the Silurian. This paper reviews activities during 1960, summarizes the discoveries made to-date and the pertinent exploration data relating to the prospects of the region and discusses some of the economic aspects of exploration and development. D URING the last few years there has •been a marked renewal of interest in the old petroleum

Jan 1, 1961

By Habib Zughbi, Paul Zulli

"A key step towards sustainability in iron and steelmaking is to optimise the use of raw materials and energy consumption, and consequently minimise CO2 emissions. Models based on a Process Integration (PI) approach play a key role in evaluating various scenarios and the impact of introducing changes in raw materials and operational conditions on the overall energy consumption and CO2 emissions. BlueScope uses a PI based comprehensive model for its Port Kembla Steelworks (PKSW), called the Integrated Steelworks Energy and Emissions Model (ISEEM). ISEEM is tightly coupled to the configuration of PKSW. It is based on mass and energy balances as well as thermodynamic relationships. ISEEM is a steady-state model and is used to predict overall and detailed unit-by-unit energy consumptions and CO2 emissions. It is also used for plant-based scenario modelling. This paper investigates the impact of major changes to PKSW configuration, including the shutting down of a blast furnace and cokemaking battery, on the energy consumption and CO2 emissions of the plant. It discusses some of the issues involved in updating the model and some identified opportunities."

Jan 1, 2015

By E. R. Weltevreden, C. Klauber, C. Vernon

"In this paper a review of the current status in recycling technologies for cathode ray tubes is given for both the glass and phosphors. Particular emphasis is placed on the opportunities for the recovery of the rare earth elements (REE) from the phosphor coatings. This is placed in the market context of alternative virgin sources and some of the advantages and disadvantages for REE waste recovery. Future opportunities are explored and also some experimental detail on a low cost leach system is presented. INTRODUCTIONThe disposal of cathode ray tube (CRT) based colour televisions has accelerated world-wide with the development of high definition flat screen panels. The total number of colour CRT televisions that have been sold in the United States in the mid-20th century is estimated to have been over 2 billion (U.S. Environmental Protection Agency, 2007), with high current rates of disposal. It is estimated that of the 20 million televisions annually discarded, 78% are send to landfill (Nnorom, Osibanjo & Ogwuegbu, 2011). However, this easily accessible item of electronics cannot only be turned into a valuable resource using the right recovery procedures, it can also prevent the substantial environmental contamination arising from improper disposal. In this review we focus on previous and current work performed on the recycling of CRT based televisions. Due to the increasing demand for rare earth metals, the main focus will be on the possibilities and challenges of recycling the fluorescent phosphor powders on the CRT’s panel glass.CATHODE RAY TUBE’S GLASS RECYCLINGConventional cathode ray tubes consist of three main parts, the panel, the funnel and the neck (Figure 1). To produce the different colours on the screen, the inside of the panel is coated with a matrix of hundreds of thousands of small phosphor dots. Each dot is one of three types of coloured phosphors, emitting either red, green or blue light. These emit light when excited by a beam of electrons generated by electron guns located in the neck of the CRT. These beams pass through holes in the shadow mask and excite the phosphor coating on the inside of the panel, to give light of variable RGB composition, see Figure 1."

Jan 1, 2012