Search Documents

By Michel Robert

"In 1974, Copperfields Mining Corporation and Soquem formed a new company, Niobec Inc, to bring the niobium deposit of the St-Honore carbonatite into production.St-Honore is located in the Saguenay area, near the cities of Chicoutimi and Arvida, and about one hundred and forty (140) miles north of Quebec. The discovery of the carbonatite complex was made in the fall of 1967 as a result of an airborne radiometric survey in search of uranium. The detailed exploration of the carbonatite indicated two niobium-bearing formations besides the original discovery of a rare earths zone. During the following years, the niobium formations were defined by diamond drilling and a decline was driven down to obtain adequate samples for metallurgical evaluation. In 1974, after seven hundred (700) bench scale tests, eleven (11) months of pilot plant 2nd a worldwide market research, a joint decision was made to initiate the development of a fifteen hundred (1500) T.P.D. mine and mill, under the management of Teck Corporation. The construction of the facilities were completed in early 1976 both on time and within budget. Niobec is now the only north american and the world second largest producer of Niobium concentrate.The process used at Niobec was developed from the pilot plant programs and later modified by the mill personnel. A simplified flowsheet for this process is shown on the slide. Briefly, run of mine ore is crushed to minus 5/8"" and fed to a rod mill, ball mill, and screens circuit where the ore is ground to 92% passing 65 mesh. The ore is deslimed in two stages of cycloning, and the final cyclone overflow at 85% minus 11 microns goes to waste. The cyclone underflow is conditioned prior to flotation of a carbonate-apatite concentrate. This concentrate is cleaned twice and then pumped to tails. The carbonate rougher and cleaner tails are cycloned in two stages to change the process; water and then sent to the pyrochlore rougher flotation. The rougher concentrate is cleaned five times. This is followed by pyrite flotation to remove sulfur, leaching with hydrochloric acid to remove phosphorus and dyed to less than 0.1% moisture before being sent to packaging."

Jan 1, 1978

By ANNE FUZESY

Soluble potassium salts in bedded underground salt deposits supply most of The world demand for potassium f or agricultural and industrial use. The potassium salts, sylvite and carnallite, were f irs, noted in drillcores in southern Saskatchewan during The search for oil and gas in ihe early /940s. Problems in shafi sinking beset pioneering potash companies, however, and cominuous production did no, begin uniil 1962. Powsh deposits in southern Saskatchewan occur within ihe uppermost 60 111 of the Middle Devonian Prairie Evaporite a, depths in excess of 900 m. Four groups of po/ash-bearing haliie beds have been distinguished: the Esierha-::,y, White Bear, Belle Plaine and Paiience Lake members. Powsh deposiis extend a jell' kilomeires into Manitoba and south imo orth Dakoia and non heasiern Moniana. Individual potash-rich beds are extensive and consistent in grade and Th ickness. Local th ickening occurs where carnallite is the dominani poiash mineral. Th e preferred ore, sy lviniie, is a clean mixiure of sylvite and haliie. Carnalliie and insolubles are avoided wherever possible because of Their detrimenwl effects on mine stability, grade and refining. Sy lvin ite is exTracted by underground mining or brought TO swjace as brine in solution mining. Poiash is separaiedfrom halite byfloiation or sequential crystallization. The refined produci, potassium chloride, is employed as a fertilizer ingredient as well as in chemical and other industrial capaciiies. The ten poiash mines of Wesiern Canada all are in Saskatchewan and account for aboui 25 per cem of world production. Faciliiies are being expanded, and a new mine and refinery was planned for ihe Breden bury area. Deposiis in Manitoba also were being evaluaied.

Jan 1, 1984

By S. M. Moon

Today, underground exploration is spotlighted as an infinitely developable area. For this purpose, many tunneling technologies were created. And until this very day, many techniques are being developed for more efficient underground movement. Although previous technologies have been developed and now being used in various forms like TMB, struck propulsion method and hydraulic propulsion method, it is hard to find a robot type exploring in small scale. But development of small scale underground exploration robot is a promising research subject for its usage in examination of soil, mineral, and subterranean resources, investigation of hazardous regions, and the military. So we developed a robot that can dig and move underground, inspired from the motion of earthworm and mole cricket. Earthworm and mole cricket dig the soil in the front and draw it off backward, so that they can move forward. We developed a mechanism that uses 2 rotating solid of revolution (bits) for pulverizing the firmly united soil in the front and put it inside the body. The bits rotate in the opposite direction of each other. While moving forward, the soil in the front moves along the spiral on the bit and is saved inside the body. The soil saved inside is taken out through an outlet in the back by a ventilation system. The ventilation system on the ground blows through a hosepipe connected to inner part of the robot and the air blows off the soil. The moving mechanism of exploring underground can be classified into 2 parts. One is to fix the blade link on the soil in a form of 4-bar link. The other one is to move forward rotating the whole link. When the blade link system for movement rotates a certain degree, one blade link is fixed, while the other one is folded in. When 2 blade links of different length rotate as it is, different torque is applied on each link. By the law of action and reaction, the link that has larger torque leads the rotation and movement.

Aug 1, 2013

By John H. Fowler

"Most of the aggregate used in Nova Scotia is produced from numerous glaciofluvial and ice-contact deposits scattered throughout the province. Production from bedrock sources is increasing, with most of the coarse aggregate used in the Halifax-Dartmouth area coming from quarries operating within the metro area.A recently completed provincial sand and gravel inventory mapping program has identified some ""resource-poor"" areas where comprehensive aggregate evaluation programs are underway. Although some areas of the province are experiencing aggregate supply problems, large volumes are exported to markets as far away as Bermuda.IntroductionThe Nova Scotia Department of Mines and Energy has been involved with aggregate resource studies for several years, although sand, gravel and crushed stone are not designated as minerals under the Mineral Resources Act of Nova Scotia. Our role has been to provide the aggregate industry with resource data as well as provide similar information to governmental agencies involved with municipal planning, water resource studies and environmental protection regulations. Several private consulting firms use the information in many of their site development studies.We became involved with aggregates in a rather roundabout way. Several years ago, an outcry from inhabitants of a small coastal community over the removal of sand and gravel from a local beach moved the provincial Department of Lands and Forests to take action to protect provincial beaches. We were asked by the Department to provide information and to suggest alternative sources here operators extracting sand and gravel from beaches could relocate. This request initiated an aggregate inventory survey in southeastern Cape Breton, which was later extended to cover the entire province. The initial provincial sand z and gravel inventory survey provided a series of 1:50,000 maps showing the distribution of sand and gravel deposits in the province."

Jan 1, 1982

By M. B. McClenaghan

"This paper summarizes diamond exploration techniques used in glaciated terrain, focussing on indicator mineral and geochemical methods applied to glacial sediments. Understanding the ice flow history, depositional history, and stratigraphy of glacial sediments is essential to successful sampling, interpretation and follow-up of indicator mineral and geochemical anomalies related to kimberlites. Kimberlite indicator minerals survive glacial transport over long distances and the relative abundance of each mineral in till is a function of the primary mineralogy of individual kimberlites. Indicator mineral distributions observed at a regional scale define the net effect of glacial dispersal, often along different ice flow directions. Local-scale distributions define individual dispersal trains. The medium sand (0.25 mm to 0.5 mm) fraction of heavy mineral concentrates, * GSC Contribution No. 2002028 prepared from glacial sediment samples, is best suited for indicator mineral surveys. The application of till geochemistry to diamond exploration is increasing because it is significantly cheaper than indicator mineral analysis and it can be performed quickly. The <0.063 mm (silt+clay) and 0.5 mm to 2.0 mm (coarse sand) fractions provide the best geochemical contrast between background and kimberlite-rich till. Kimberlite pathfinder elements that provide good contrast include Ni, Cr, Ba, Co, Sr, Rb, Nb, Mg, Ta, Ca, Fe, K, Ti and LREE, the relative importance of which will depend on kimberlite composition and that of the surrounding bedrock.IntroductionIn Canada, glacial erosion is the principal means by which kimberlite and its associated minerals have been dispersed, from a few tens of metres to tens of kilometres down-ice. Post-glacial weathering has had little impact on kimberlite debris in the glacial sediments, thus boulder tracing, indicator mineral methods and trace element geochemistry of the fine fraction of till (“drift prospecting” methods) can be used to detect kimberlite dispersal within areas covered by glacial sediment. This paper provides a summary of drift prospecting methods for kimberlite exploration in glaciated terrain, and includes examples of reconnaissance- , regional- and local-scale kimberlite indicator mineral and till geochemical distribution patterns.Weathered kimberlite is more susceptible to glacial erosion than the surrounding bedrock, thus many kimberlites in glaciated terrain are found in low or swampy ground, under small lakes, or covered by thin (< 1 m) to thick (>50 m) glacial sediments. Glacial erosion has removed varying amounts of the pre-glacially weathered kimberlite and, in some cases, the hard competent kimberlite below. For example, glacial erosion of the Peddie, McLean and Seed kimberlites near Lake Timiskaming, Ontario, removed pre-glacially weathered kimberlite, leaving a polished striated subcropping surface (McClenaghan et al., 1999a). In contrast, glacial erosion of the B30 kimberlite, near Kirkland Lake, Ontario (Fig.1), was much less vigorous and left a >10 m cap of soft and highly weathered dark green clay-rich kimberlite (McClenaghan et al., 1996). The thickness of remaining pre-glacially weathered kimberlite will influence the geophysical signature of the kimberlite."

Jan 1, 2002

By Karl J. C. Harries

"10.1. INTRODUCTIONDefinitions are a necessary part of every agreement. Their purposes are to assist the reader in reading and understanding an agreement and to attempt to avert potential confusion and, therefore, disputes. In some circumstances, they may be critical in deciding a dispute. As they are often substantive, they should not be treated lightly.It is far easier and less confusing for a reader to read “the Company” or “the Recipient” than to be faced with “the party of the First Part”, or to see the “Jones Property” than “that part of the property hereinbefore described in paragraph 1.01 hereof”. It is also advisable not to use “-ee” and “- or”, as in payee and payor.One thing must always be remembered: once a word has been defined in an agreement, it will always have the defined meaning unless the contrary is clearly indicated or is required to make sense of a provision.2 It can be confusing for a reader if commonly used words are defined in other than ordinary terms. Unique words that will stand out in the text are more likely to be recognized as having special meaning. It is also good practice to identify defined terms by capitalizing them in the text of the agreement. Boldfacing of definitions is also sometimes used for this purpose but, as boldfacing is not easily identified in handwritten revisions, it can be missed in the press of negotiations, especially when several typists are involved. Lack of consistency in identifying defined terms is not a fatal mistake, but it can create confusion, especially if the reader is new to the agreement or is reading it in a highly technical manner, such as when there is a dispute.If definitions used in the main text also apply to a schedule, they need not be included in both. Omitting them from the schedule makes the agreement look shorter, which to some people is a benefit. If definitions are not repeated, make certain that the schedule clearly indicates that words defined in the main text have the same defined meanings in the schedule3 and are clearly identified as defined words. In considering whether or not to repeat in a royalty schedule definitions appearing in the agreement proper, think of definitions as an aid and a reminder to the reader. Repeating them will help a reader, if only by saving the nuisance of remembering where to find them in the main text and constantly turning to it. All the definitions needed to read the schedule will be right there, so that the schedule is a self-contained document. Just make certain that, if you do repeat a definition, you repeat it in identical terms. If you have to change any defined term to make it fit the royalty provisions, use a different word or phrase as the defined term to warn the reader that he is dealing with a different concept.4"

Jan 1, 2003

By G. Taylor

"The Iron Ore Company Of Canada's Carol Project is located in Labrador City, Newfoundland. Labrador City is some 912 air kilometers northeast of Montreal, and 417 ratl kilometers north of Sept-Iles, Quebec.Over 2,800 employees work at the Carol Project to produce some 20.0 million tonnes of concentrate and 10.5 million tonnes of pellets annually.In 1979 our Training Department started to develop the DACUM System of training for our Concentrator Operations Department.DACUM is an individualized, self-learning, training program. It is both a curriculum plan and an evaluation instrument.To date, the DACUM System has been completed for all occupations in the concentrator and work will commence shortly to develop DACUM for our Pellet Plant and Mine Operations Departments."

Jan 1, 1982

By G. E. Cole

"Amongst the mineral products of Canada gold holds the second place in value of yearly output. . . . . .The production of gold has increased steadily during the past six years and has somewhat more than doubled in that time. For the past four years Canada has been third among the gold producing countries of the world, surpassed only by the Union of South Africa, and the United States of America," and now yields somewhat more than 9 per cent of the annual output of the world."-"The Gold Situation in Canada". Bulletin of Development Branch, Canadian Pacific Railway. The history of gold mining in Canada is comparatively modern and does not take one further back than the late &apos;fifties of the 19th century. If the efforts of the early explorers in Canada were expended in "seeking with equal ardour, proselytes and gold", history fails of any record of their success in the search for the precious metal. As early as 1849 not a few Canadians travelled from the east by land and water to the Californian goldfields. In the then settled part of Canadathe east-people were alive to the value of any mineral discovery; but the west, owing to its remoteness and to there being no ready means of communication, was virtually isolated from the east.

Jan 1, 1927

By Jay F. Colinet

Researchers at the Pittsburgh Research Laboratory (PRL) of the National Institute for Occupational Safety and Health (NIOSH) work to reduce respirable dust exposures in mining operations. One focus of this research is silica dust control for surface and underground operations in the metal/nonmetal mining industry. PRL researchers analyze dust sampling results from the Mine Safety and Health Administration (MSHA) to identify high-risk occupations to guide research efforts. Research is then conducted in an effort to improve existing technologies and/or develop new controls for reducing worker exposure to airborne silica dust. During the last few years, PRL researchers have conducted research related to the following goals: improving protection provided by enclosed cabs on mobile surface mining equipment, reducing dust generation from surface drills, reducing dust levels in iron ore operations, and developing a new method to clean dust from workers? soiled clothes. A description of each of these controls and subsequent dust reductions quantified through site surveys will be provided.

May 1, 2007

By Terry Braden

"Meeting probable world mineral demand in the years ahead will almost certainly require an ability to economically treat lower grade and more complex ores. Achieving this will require extensive research and technical development across the full spectrum of mineral processing.For mid-sized or smaller companies the most effective way to participate in such extensive programs - and gain access to the technology required to stay competitive - may be through collaborative research.This paper explores the recent history of collaborative research in mineral processing and in particular its ability to attract world-class multi-institutional research teams with sufficient resources to make step-change advances. It chronicles the advances achieved, but also explores the research architecture and administrative structures required to deliver research outcomes and technology transfer mechanisms to a range of often disparate sponsoring companies.INTRODUCTIONIn medieval times the dream of alchemists was to turn base metals into gold. We modern alchemists, of course, don’t waste our time on that sort of foolishness: we turn base metals into dollars. When I see the profit reports filed by some companies recently, I can only conclude that a lot of those present today must be pretty good at this.But the fact that we are here at this conference reminds us that an alchemist’s work is never done; turning base metals into dollars is not a one-trick wonder but an art that we must extensively refine year after year if we are to survive in a competitive marketplace.It is not that demand for metals is likely to slow; most people seem to think that China, India, Brazil and other emerging economies are still at the lower end of their demand curve. They will need significantly larger volumes of metals in the years ahead. The challenge for us as processors is that to supply increasing tonnages of those metals profitably we will almost certainly need to process more complex or lower grade ores and probably to do so with reduced energy inputs."

Jan 1, 2009

By E. V. Manlapig, K. R. Rahal, J-P Franzidis

"The Floatability Characterisation Test Rig or FCTR is a highly instrumented, mobile flotation pilot plant built by Baker Process (now EIMCO) for the AMIRA P9 Project for use in flotation plant modelling and simulation studies. With the Mintek Floatstar system controlling the level in every cell, and the facility for full stream sampling on all streams, the FCTR is a unique tool for producing data of sufficient quality for flotation plant modelling. The plant was commissioned at Lonmin's Karee and Eastern Platinum concentrators in 1999/2000, and completed a number of test work programs to investigate the effect of power input and regrinding on metallurgical performance. Lonmin's experience with the FCTR has caused it to build two of its own to undertake further projects on its various mines. This paper describes the design of the FCTR and the features that make it a unique research tool, and the benefits derived by Lonmin through their experience with the unit.INTRODUCTIONAs part of the Australian Mineral Industries Research Association (AMIRA) P9 project, a new model for flotation has been developed, in which the overall recovery, R, of the jth floatability class of the ith size class of a particular mineral, is given as (Savassi, 1998):"

Jan 1, 2002

By Alice H. Zhu

Belt conveyors are widely used in materials handling industries. The bulk materials which can be transported include ores, coal, earth, grain, limestone, wood chips, fertilizer components such as potash and many others. Along with the new technology development and enhanced industrial automation requirements, belt conveyor instrumentation has also been modernized to improve conveyor availability and performance. Traditionally, belt conveyors are equipped with emergency pull cord switches to shut the conveyor down, misalignment switches to signal the belt offline condition, speed sensors to detect the belt slippage, and level switches to prevent material plugging in the discharge chute. Belt rip detectors are also normally provided for long belt conveyors. As a rule, equipment condition monitoring is not automated at most operating facilities, but is performed manually by maintenance staff via time-based surveillance. The new generation of condition monitoring instrumentation and control equipment can be successfully utilized to design a reliable, cost-effective, and centralized monitoring system, capable of monitoring a wide variety of mechanical equipment. The implementation of the condition monitoring automated system can provide continual monitoring of the plant equipment to ensure safe operation of the equipment to its required capacity. Any abnormal behavior of the motors, gear reducers and pulleys can be analyzed, alarmed, and recorded immediately, so problems can be detected and resolved before critical components failure. Therefore, the current trend is to provide the belt conveyors with condition monitoring system in addition to the traditional instrumentation, where temperature probes and vibration sensors can be installed on motors, gear reducers and all pulleys. Another innovative development is a three-in-one type belt rip detector which combines laser, tray and cord type detection together to ensure a prompt belt tear indication. The purpose of this paper is to present the latest development of belt conveyor instrumentation and introduce the application of newly developed instruments.

Nov 1, 2011

By A. J. Monhemius

"The paper reviews the history of modern iron control processes in hydrometallurgy. Particular attention is paid to the processes developed in the 1960s by the electrolytic zinc industry for the removal of iron from zinc sulphate leach liquors - namely the Jarosite, Goethite and Hematite processes. Problems faced by the industry in the safe disposal of the iron residues produced by these processes are discussed. The lessons learnt over the past half century by the zinc industry are projected on to the current efforts to develop hydrometallurgical processes for the treatment of copper sulphide concentrates. It is argued that any attempt to create a “hydrometallurgical copper smelter” is doomed to ultimate failure, unless and until methods are developed that can recover iron from solution in a form that can be directly utilised by the steel or pigment industries.INTRODUCTIONYou suddenly realise that age is catching up with you and that technology is moving on apace when you are asked to talk about the history of a process or a technology that you’ve grown up with. Such was my reaction when, out of the blue, I received an email last year from the chairman of the CIM’s Historical Metallurgy Committee, asking me if I would give a talk on the early developments of iron control in hydrometallurgy. Once I’d got over the initial shock of realising that I had now become living history, I was of course flattered that the invitation was to give a talk at the prestigious IMPC, a conference series that has been going for as long as I have been in the business. That this particular IMPC was to include the 4th Symposium on Iron Control in Hydrometallurgy, made the invitation even more appealing and appropriate, because I was the co-chairman of the First Symposium on Iron Control, together with my old friend, John Dutrizac (known by many as Dr Jarosite), which was held 30 years ago in Toronto.first became involved with iron at the very start of my career in hydrometallurgy – the research topic for my Masters degree thesis at UBC, back in the mid 1960s, was “Reductive leaching of Goethite with SO2”. My thesis supervisor was the late Professor Ian Warren, who himself was a protégé of Professor Frank Forward, one of the founding fathers of modern hydrometallurgy. Little did I realise at that time, now 50 years ago, that the problem of iron and how to deal with it in hydrometallurgical processes would be a theme that followed me throughout much of my 40-year career in academia."

Jan 1, 2016

By Jack Zhang, Yunguo Tang, Baodong Zhao

"Rare earth elements (REEs) have numerous key applications in both traditional and advanced technologies. A shortage of some critical REEs is expected due to the discrepancy between the REE abundance in REE deposits and the REE demand from the market. For example, Neodymium, Europium, Terbium, Dysprosium, Erbium and Yttrium are expected to be in short supply. REE recovery and separation from secondary resources such as uranium wastes, heavy mineral sands, and recycled materials can balance the shortfall in a cost effective way.The Saskatchewan Research Council (SRC) is engaged in the development and commercialization of complete REE recovery and separation technologies in Canada. One of SRC’s newest developments is the design and commissioning of a heavy rare earth (HREE) separation pilot plant. The pilot plant uses hundreds of stages of solvent extraction (SX) to produce high purity individual HREEs from both primary and secondary resources.This paper presents the design of an HREE recovery process for the particular case of uranium processing wastes. The separation results of a group separation are reported and discussed, as well as the issues and the challenges of the development, commissioning and operation of the continuous SX pilot plant.IntroductionSignificant amounts of strategic specialty heavy rare earth elements (HREEs) are found in uranium wastes in Saskatchewan. It estimated that about 47 tonne/a of heavy rare earth element oxides (HREO) including 27 tonne/a of Y2O3, plus 6 tonne/a of Sc2O3 are in the raffinate of every uranium mill for potential recovery. Since the HREEs are already in the raffinate, cost effective HREE production is promising in Saskatchewan.Selective precipitation including nutraulization, oxalate and double-salts precipitation, as well as sulfide precipitation, ion exchange (IX) and SX are commonly used technologies for the recovery and purification of REE solution. REE oxalate precipitation is an effective technology to remove Fe, Al, Ca, Si and other impurities by taking the advantages of the solubility difference between oxalates of REEs and impurities in acidic solution (Xu, 2005)."

Jan 1, 2017

By John G. Peacey, Leoncio Sevilla G., Ford. Kevan J. R., Erling Villalobos C.

"Kinross Gold Corporation’s Mantos de Oro (MDO) gold/silver mine in northern Chile currently processes 15,000 tpd of oxide ores through a mill, whole ore cyanide leach plant followed by a Merrill-Crowe refinery. With the expected depletion of these oxide ores in a few years a new sulphide mineral deposit, Ladera-Farellón has been identified to potentially replace existing ore reserves. The deposit contains approximately 0.5g/t Au, 6g/t Ag and 0.5% Cu. The principal sulphide mineral in the deposit is enargite (Cu3AsS4) which hosts the majority of gold and silver and the copper. Direct cyanidation testwork has shown the sulphide mineral is refractory with a low gold recovery of 36% and silver recovery of 45%. Oxidation of the sulphides is required to liberate gold and silver and allow recovery of copper as an important pay-metal. Therefore, at MDO a new metallurgical process route with oxidation as a pretreatment step is required for viable treatment of such new sulphide mineralized material with acceptable recoveries of pay-metals.Analysis of flowsheet options was completed based on bench-scale and pilot scale metallurgical testwork as well as with reference to existing studies and operations. The process options investigated assume concentration of sulphides by flotation, followed by either pressure oxidation, bacteriological oxidation or roasting. Preliminary evaluation of flowsheet options focused on process risk, operability, technology availability and the economics of the project with emphasis on use of the existing metallurgical plant to reduce capital cost. Operating costs for each process option were also included in the relative analysis.The challenges of treatment of MDO sulphides, principally enargite and pyrite for recovery of gold, silver and copper center on fixation of arsenic and sulphur capture with environmentally acceptable disposal of residue tailings. This environmental focus was included in the process option selection and comparative analysis.This paper presents a review of the process options considered and highlights comparative advantages/disadvantages of each process with associated environmental issues. Preliminary conclusions are drawn on roasting as a potentially favorable process option for the treatment of MDO sulphides."

Jan 1, 2009

By J. A. King, D. A. Knight

"The Porgera orebody is located in mountainous terrain in Enga Province, Papua New Guinea. An underground mine has been developed which produces up to 2000 t/d of ore grading over 2 ozs Au/t. Some 79% of the gold in the ore is free, with the balance in a highly refractory form as sub-microscopic gold evenly disseminated within a pyrite matrix.This paper describes the metallurgical plant that uses flotation and cyanidation circuits to effectively recover the free gold in the ore feed, allowing for wide variation in the gold head grade. The refractory gold component in the ore is stored as leached pyrite flotation concentrate and this concentrate will be later treated by autoclaving techniques to recover the contained gold.The ProiectThe property is located in the Porgera Valley 600 Km North West of Port Moresby. The remote location is 2500 m above sea level. The mine area has 3600 mm of annual rainfall and a temperate climate with temperatures ranging from 10° c to 22° c throughout the year.Alluvial gold was reported in the Porgera area in 1938 and has been an important source of revenue for the area for many years. Intermittent exploration was carried out until the 1960 1 s when Placer (PNG) Pty. Ltd. with Mt. Isa Mines commenced an extensive exploration program. The property was brought to production in 1990 by the Porgera Joint Venture group consisting of Mount Isa Mines Ltd, Rennison Goldfield Consolidated Ltd. and Placer Dome Inc, each with a 30% ownership and the Government of Papua New Guinea with a 10% share. Placer Dome Inc. is the manager of the property with construction under the direction of the Placer Dome Technical Services group."

Jan 1, 1992

By \/eena Sahajwalla, Jonathan Dicker, Paul O'Kane, Cath Skidmore, James Dankwah, Magdalena Zaharia, Rita Khanna, David Knights, N Saha-Chaudhury, Somyote Kongkarat

Due to the inherent limitations of current methods of disposal of end of life polymeric materials, avenues are researched towards developing alternative, environmentally friendly and economic recycling processes. Different polymeric materials (i.e. rubber, high density polyethylene (HDPE) and polyethylene therephtalate (PET)), quite distinct in terms of chemical structure and composition, were considered in the present study as carbon resources in EAF steelmaking. Investigations were conducted in both laboratory and industrial scale steelmaking to assess the effectiveness of using these materials as carbon sources for slag foaming in EAF steelmaking. Slag foaming is important because it enhances furnace efficiency.

Jan 1, 2011

By K. Meyer

"INTRODUCTIONThe David Bell Mine Concentrator started production in April 1985. A staff of twenty-seven people operate and maintain the concentrator. The crew is grouped into the following main areas.16 Operators6 Assaying/Metallurgy/Refining/Clerical4 Maintenance people2 SupervisionOperating highlights of the following unit processes will be discussed in detail:Screening and ThickeningPre-aeration and CyanidationCarbon-In-Pulp Gold AdsorptionCarbon Handling andGold RecoveryFor a complete description of the concentrator, refer to the papers by: (1) C.V. Sibbald, Teck-Corona's Hemlo Mill, October 1984, (2) R.A. Ford, The David Bell Mine at Hemlo, From Exploration to Production, November 1987. For operating details of the grinding circuit and effluent treatment plant refer to papers by: (3) T.G. Smith, SAG Mill Experience at The David Bell Mine, October 1988, ( 4) AN. Veltmeyer, The Effluent Treatment Plant of The David Bell Mine, January 1989.TRASH AND CARBON SCREENSTrash ScreenThe vibrating trash screen is inclined at 5 degrees and is clad with a 28 mesh stainless steel cloth which is changed monthly during the SAG mill liner replacement/inspection shut down. Other screen openings and configurations have been tried and the screen has been by-passed to change the cloth ""on the fly"". These attempts resulted in fibres (usually wood) to report to #1 Carbon-In-Pulp (CIP) tank, where the fibres are trapped in the CIP launder screens, and downstream carbon handling screens causing serious blinding problems. The trash screen in a Carbon-In-Pulp (CIP) or Carbon-In-Leach (CIL) gold mill removes fibres before they:are reground in the ball millsaturate with gold bearing leach solutionplug launder screens in CIP or CIL tanksplug carbon circuit pipe screenstherefore the trash screen is best placed ahead of the thickener."

Jan 1, 1989

By J. P. Van Cruyningen, M. J. Puro

"A 2400 acre extension to the existing Tailings Area is under development at Inco's Copper Cliff Milling operations.The new area is being developed in stages as production levels dictate thus minimizing immediate capital expenditures while permitting disposal operations to proceed as further site work progresses.The first stage of the new storage site will be fully operational by early 1987 and will include a 400 acre site specific to the storage of Pyrrhotite rejected from milling circuits. The Pyrrhotite site is located in the centre of the Tailings area and is designed for water cover throughout much of its projected life.The new development incorporates perimeter dams designed to operate with low phreatic levels for maximum structural stability. Acid seepage water is collected behind secondary impermeable dams for return to the Tailings Pond.Tailings are deposited by up-stream methods permitting segregation of coarse fractions for use in future lifts of the perimeter dams."

Jan 1, 1987

By M. Sahoo, P. Burke, Y. Fasoyinu, J. P. Thomson

The effects of grain refinement, mold temperature and chemical composition on the hot tearing resistance of aluminum alloys 535.0 and 206.0 has been studied by pouring constrained rod castings in metal molds. In addition, two prototype components that could be used in automotive applications were also poured from both alloys by gravity tilt-pour and low pressure permanent mold casting processes. This paper summarizes the results and issues encountered during the casting trials. It was shown that grain refinement and mold temperature ::::: 400°C reduced, and sometimes eliminated hot tear cracks in both alloys. The two prototype engineering components could be cast successfully from both alloys in metal molds. The metallurgical issues related to molten metal treatment and processing temperatures were well controlled. However, issues related to the control of hot tearing, casting and mold design must be addressed in future studies to guarantee the production of defect free castings.

Jan 1, 2006