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By Michael B. Cortie

The young field of nanotechnology has as its objective the design and construction of useful devices made of nanoscale materials. Objects or structures which have at least one important dimension in the range 0.5 to perhaps 50 nm may be considered to be in the nanoscale domain. These sizes lie far below the 200 nm or so that can be resolved with an optical microscope, and are closer in size to the 0.3 nm diameter of individual atoms. Nanotechnology, which is the study and exploitation of these tiny structures, is attracting keen interest at present. The excitement is motivated by the observation that control of matter at the nanoscale holds the promise of faster computing, better medicines, and smarter materials. In this paper, the physical phenomena on which this optimism is based are broadly discussed and explained. Where appropriate, examples of the rather different and curious properties of gold at the nanoscale are used to illustrate the points covered.

Oct 1, 2003

By S. J. Cook

Outstanding advances among the metals, marked the mineral production records for Canada during the first half of 1925. Production of metals and non-metals reached a total value of $90,347,698. as compared with $84,307,385. in the first half of 1924, an increase of 7.16 per cent. Metals and non-metals produced during the calendar year 1924 were valued at $17 4,202,537.; production during the first half of 1925 showed a sum equal to 51.86 per cent of this total. Advances among the metals were general. Gold rose to a new record. Lead advanced 62.41 per cent over the high mark attained in the first half of 1924. Nickel production was well maintained. Copper was up a million pounds. Silver showed increased values. Zinc followed the trend in lead to almost double the output recorded in the first half of 1924. Cobalt production continued to improve. Despite the loss due to the protracted strike in the Nova Scotia coal mines which reduced the output of coal in that province; during the six months ending June, to less than half the tonnage reported in the first six months of 1924, improved conditions throughout the rest of the non-metal mining field resulted in the production of non-metals during the half-year reaching a total value of $31,199,233. as compared with $36,844,286. in the first half of 1924; the loss in the value of coal output al one amounted to $5,723,873, while the decrease in the aggregate value of non-metals amounted to only $5,645,053.

Jan 1, 1925

By P. Cain, B. Martens

"Grande Cache Coal (GCC), an investor-owned Alberta company, is in the final stages of the regulatory process leading to the resumption of coal mining in the Smoky River Coal Field of Alberta. Although many opportunities for low-cost, high-yield mining remained on the property, GCC opted for a long-term production plan that ensures stability for the local economy, sustainable use of the resources in the area, environmental responsibility and a satisfactory return for its investors.GCC entered the Alberta coal approval process in late 2000 with a public disclosure document. In October 2001, GCC formally submitted an application for mining approval and an environmental impact assessment (EIA) to the government and the public. The application covered the proposed Grande Cache Coal project, which includes the No. 7 underground mine, No. 8 surface mine and coal processing operations. The EIA provided a comprehensive investigation of environmental sensitivities in the project area, matched with environmental protection programs. The project is based on commencement of operations in late 2002. GCC’s plans are founded on a commitment to sustainable development and has framed this commitment in the context of a long-range mine development plan that will sustain the community of Grande Cache over the next 25 years. The Grande Cache coalfields offer extensive coal reserves and opportunities, for both surface and underground mining. Combining highly productive U.S.-style room and- pillar underground mining methods and conventional truck-and-shovel open pit mining, GCC’s approach to sustainable development encompasses community involvement and reclamation of mine sites to productive land uses after mining."

Jan 1, 2002

By D. Royston

In SAG mills fed with a variety of ore types, hard packing between the shell lifters can come and go depending on rock type and rock size distribution and the presence of a binder. Packing can appear in all sizes of SAG mills, and can be tenacious. High ball impact forces (depending on ball size) in larger mills may compact and encourage packing. Packing can have a negative impact on milling performance and a change in shell liner design may be required to remove it. However shell liner design changes need to be managed with care to ensure liner reliability. In smaller mills control of packing can extend shell plate wear-life and may help to maintain milling performance in fixed-speed mills through the liner wear-cycle.

Jan 1, 2012

By Diankun Lu, Ganfeng Tu, Edouard Asselin, Feng Xie

A novel separation process for detoxifying cadmium-containing residues arising from zinc hydrometallurgical processes has been developed. An initial investigation indicated that a high concentration of zinc in the sulfate solution can be effectively separated from cadmium by solvent extraction with P204 (di(2-ethylhexly)phosphoric acid, D2EHPA). The mixture of sulfuric acid and ammonium citrate ((NH4)3C6H5O7) is thus used to extract metals from the residue at room temperature. Copper in the leachate is recovered by solvent extraction (SX) with LIX 973. Cobalt in the raffinate from the copper SX process is recovered by precipitation with a-nitroso-ß-naphthol. The results show that more than 50% of the copper and virtually all the zinc, cadmium and cobalt in the residue can be leached under the experimental conditions used here. Virtually all dissolved copper and cobalt can be recovered in the subsequent solvent extraction and precipitation processes. The presence of (NH4)3C6H5O7 could significantly facilitate the extraction of zinc by D2EHPA in the subsequent separation of zinc and cadmium. More than 97% of the dissolved zinc can be recovered through a two-stage counter current solvent extraction process. After separating copper, cobalt and zinc, cadmium can easily be recovered from the solution either by cementation with zinc powder or by electrowinning, while the purified solution can be recycled back to the leaching process.

Jan 1, 2014

By R. W. Baker

"The development of uppers drilling at Brunswick Mining is reviewed. This paper describes design criteria for drilling patterns and the research required for selection of a suitable drill jumbo. The success of the uppers drilling program based on operating procedures is highlighted. IntroductionBrunswick Mining and Smelting Corporation Ltd., operates a 10 500 tonnes per day lead /zinc/copper I silver underground mine some seventeen miles southwest of Bathurst, New Brunswick .The No. 12 orebody, first discovered in 1952 by a group headed by M.J. Boylen, had extensive development, including two shallow shafts (500 ft), and test work carried out on it by St. Joe Lead between 1953-1957. However due to complex metallurgy and depressed metal prices, the operation was suspended.In 1961, a group comprised of M.J . Boylen, K.C . Irving and Patino acquired the rights of St. Joe Lead to the No. 12 property. A concerted development plan was initiated along with construction of the necessary sur face facilities and by July 1964, the property was in production at 4500 tons per day.In 1967 Noranda Mines Ltd. acquired operating control of Brunswick Mining and Smelting Corporation Ltd."

Jan 1, 1988

By J. K. Gowans

"INTRODUCTIONTo bring a mining property into production in the Canadian High Arctic a company must deal with the harsh environment, the short shipping season and the high cost of labour. In trying to minimize the effect of these factors, the concept of a barge-mounted process plant was investigated as an alternative to the conventionally built concentrator. Cominco's previous experience gained at the Black Angel Mine on Greenland's west coast suggested that this would be a practical alternative.The normal shipping season at Little Cornwallis Island is approximately six weeks long, from mid-August to the end of September. All equipment and materials must be delivered during this small ''shipping window."" The logistics problems are enormous; if the conventional approach had been used the major process equipment would have been delivered to Little Cornwallis Island at the same time as the completed barge actually was! Construction would also be starting at the start of the worst climatic conditions, the Arctic winter. Nine months production was gained by opting for the ""Barge"" approach.What the Arctic winters do to the shipping season, so do they affect the productivity and the cost of labour. Construction labour must come from southern Canada. Thus higher transportation costs and higher wage rates, with more overtime and incentives, increase the labour costs to approximately 50% over normal southern rates. Couple these rates with the lower productivity involved with men working in the extreme cold temperatures and the net effort is worth avoiding. A process plant being constructed in Southern Canada can take advantage of more accessible labour at lower costs, increased productivity and a faster construction schedule. The barge concept must still deliver the equipment and materials during the ""shipping window"" but it can in the completed form."

Jan 1, 1983

By Harry Siewert

"The commissioning of the 4th concentrator (C4) at Freeport Indonesia in early 1998 increased total mill throughput from 130k to 230k tonnes per day. The C4 flowsheet consists of a single 38 ft diameter SAG mill, four 24 ft diameter ball mills followed by four banks of 4,500 ft3 WEMCO flotation cells.The design of the C4 rougher flotation circuit was based on the expectation that the copper and gold recoveries achieved with the 4500 ft3 flotation cells would be equivalent to or better than that achieved with the 3,000 ft3 flotation cells in the 3rd concentrator (C3) rougher circuit. This assumption was due to the fact that the C4 flotation feed size would be less than 15% +212 microns compared to the C3 rougher flotation feed size of less than 23% +212 microns. By mid 1998 it had become apparent that the C4 rougher flotation copper and gold recoveries were below those predicted.In order to determine the cause of the lower recoveries, stage by stage rougher flotation surveys were performed in all four concentrators. The results of the surveys showed that the C4 rougher flotation circuit had a lower recovery of +200 micron material than that achieved in the C 1, C2 and C3 concentrators. Through mineralogical analysis, it was determined that a majority of the copper contained in the +200 micron fractions was liberated and recoverable. This paper describes the steps taken to increase coarse particle recovery, overall plant recovery and the results achieved."

Jan 1, 2001

By P. Talonen

Since the last Iron Control in Hydrometallurgy Symposium in Montreal in 1996, the Kokkola zinc plant has increased its capacity from 175,000 t/y to 280,000 t/y by installing an atmospheric concentrate leaching process, which has also affected iron control in the leaching circuit. Major changes have been made at the jarosite residue pond; a subterranean plastic wall reinforced with bentonite and cement has been built around the pond. A new water collecting system that is used for groundwater level control in the pond area was installed. With these two investments in the pond area, it is now possible to prevent any seepage flow from the pond into the surrounding environment. Water pumped from the residue pond is treated in the water treatment plant. This paper describes the behavior of iron in Kokkola's current leaching processes. The treatment of the jarosite, the improvements to the residue pond and the water treatment process are also described.

Jan 1, 2006

By G. Mousavian, R. Bagheri, N. Dalili

Polypropylene (PP) and its composites have an increasing use in automobile and domestic industries. Since the published results on strain rate effect on yield behavior do not match, and there is a high attention paid for effect of nanometeric fillers on deformation behavior of composites, in this research the strain rate effect on yield behavior of PP and the effect of nanometeric fillers on deformation behavior of PP have been studied. Microscopic observations and tensile tests in different strain rates on neat PP samples and on samples filled with 5, 10 and 15 %wt have been used. A dramatic change in behavior for the modulus and post-yield slope curves when the strain rate is between 0.0433-0.05 s-1 has been observed. Microscopic observations on PP indicate a change in deformation mechanism from shear yield to crazing at the same strain rate that the change in behavior of curves occurs. It has been observed that in PP nanocomposites with higher amount of calcium carbonate, fracture in early stages of deformation occurs in lower strain rates. In other words for a fixed stain rate there is a critical filler percentage such that if the filler percentage is higher then early-stage fracture will occur. Similarly for a fixed filler percentage there is a critical strain rate and in higher strain rates early fracture will occur. The critical stain rate will decrease as the filler percentage increases and vice versa.

Jan 1, 2006

By Yan Yang

The Jinfeng gold mine is one of the three gold mines that Eldorado Gold has in China and it is the second largest gold mine in China. The mine is located in a relatively remote and mountainous area in the southwestern Guizhou province. The orebody is similar to the Carlin type deposit in Nevada. The mill throughput was designed to treat 3,600 tones per day. The ore comes from open pit mining and underground mining, and is fed to one-stage jaw crushing. The crushed ore is stockpiled, reclaimed and then fed to the SABC grinding circuit. After classification with hydrocylones, the ore is floated, and the resultant concentrate is oxidized biologically in a process known as BIOX®. The oxidized concentrate is then washed in a CCD circuit and finally leached with cyanide in a CIL circuit for gold extraction. Jinfeng produces about 180,000 oz of gold per year. This paper introduces operations and modifications of SABC circuit over the past three years, and then describes some technical characteristic of the SAG mill and other circuits in the processing plant. Major modifications and improvements on the SABC circuit are described in the paper, including: 1. Impacts of grinding ball and mill liner with respect to material selection, quality, hardness, manufacturing methods, and interactions between mill liner and grinding ball. 2. Effect of milling operation parameters on milling efficiency. 3. Impacts of SAG mill scats and modifications of grate size to improve mill throughput. 4. Design and construction of a pebble crushing system, and recycle the crushed scats to the SAG mill to improve mill throughput. With the above-mentioned modifications, 20% increase over the design in mill throughput has been realized over the past three years, and operating cost has been significantly reduced. However, some issues still remain, and thus process modifications and technical innovations are still needed.

Jan 1, 2012

By L. Vollert

In-situ recovery of metals is presently experiencing a revival not seen since early applications in amenable copper oxide deposits, uranium and generally applications where neither, porosity and permeability, nor process chemistry have been prohibitively difficult. With ever decreasing grades in current mining operations or Greenfields projects and ever increasing capital and operating costs, in-situ recovery is looked to as the processing option that will both unlock these deposits as well as potentially derive revenue from mineralised waste remaining in the ground once traditional mining and processing methods become uneconomical. In-situ recovery is also being looked to as a mining method that minimises the environmental impact sustained in the application of traditional energy and water intensive mining and processing operations where millions of tonnes of ore are mined from the earth, processed on surface and then disposed of in both waste dumps and tailings facilities. The key challenge facing companies like Newcrest is that these low-grade deposits or remnant mines are generally hard rock applications that require costly methods to liberate the valuable minerals. A further challenge includes identifying suitable chemistries that both facilitate the economic recovery of gold and copper and that may be considered environmentally acceptable. This paper presents a desktop study whereby the issues of access creation and chemical extraction are discussed and evaluated with a view to driving future research in the area and unlocking this application as a real processing option. INTRODUCTION Mining companies are increasingly challenged by low grade, deep and complex ore deposits which are no longer economically exploitable by current methods. The large footprint of current open pit operations can present obstacles for permitting and social acceptance. For these reasons in-situ recovery (ISR) technologies are receiving renewed attention as a technology which could be used to exploit these more complex deposits economically and with less environmental impact. The environmental impact may be further reduced if emphasis is placed on use of renewable energy sources rather than traditional grid power, gas turbine or diesel generators are employed to drive the operation. A potential renewable energy driven ISR mine of the future is shown in Figure 1.

Jan 1, 2019

By B. M. Das, D. B. Cross

"In June 1983, the Computer Applications and Process Control Committee (CAPC) of the Canadian Institute of Mining and Metallurgy (CIM) circulated a questionnaire to coal mining, exploration and consulting companies in Canada to determine the industry's level of interest in holding a workshop-style meeting to introduce company personnel to ""state-of-the-art "" computer systems designed to carry out specific technical and management junctions. It was necessary to conduct the survey to determine the specific fields of application and the nature of training which are of most interest.Almost universally, the companies expressed interest in computer workshops and training for applications in the Canadian coal industry. The survey showed that all categories of personnel felt the need for some sort of training. Areas of specific interest identified were: exploration and geology, mine design, reserve calculations, coal mining technology, coal preparation, rock mechanics, ventilation, financial planning, and process simulation. The details of this survey together with an assessment of the significance of computer applications in the Canadian coal industry are presented in this paper."

Jan 1, 1986

By R. A. S Villegas

The Brazilian government announced in 2007 its plans to reactivate the nuclear program. As a result of this decision, a new nuclear power plant is already being built and there are studies dealing with, among other activities, the building of 4 to 8 new ones until the end of 2030. Such increase on the country?s uranium demand affects INB, the Brazilian state company that?s in charge of uranium supply. This paper describes scenarios predicted to the Brazilian nuclear industry for the next years and the INB plans to meet the country?s needs in terms of uranium exploration and production.

Aug 1, 2010

By G. Langlands

"R. Tenbergen Is this flotation machine suitable in the flotation ofInco ball mill discharges where we have a coarse feed at 60% solids?Reply Experience has shown that there is not a significant increase in the wear life of these machines when handling coarse material (8 mesh) at 60% solids. A common practice in Europe is shut down on the week-ends.The material is allowed to settle and on start-up an injectic of air for 15 seconds is sufficient prior to start-up. At,mining we put our unit in the middle of a bank of 44 cells and in order to ensure severe sanding we shut the aker cell down while the remaining cells kept running. After 20-25 seconds of air the cell started without trouble.P. Mahant Is there a build-up inside the impellor shaft housing? Falconbrige Ltd.Reply There is no sand build-up but rather a scale build-up which due to a flexing action frees itself periodically. Part of the design of the machine permits a water injection into the shaft housing to free any build-up. This is done in Europe during the week-end shut down."

Jan 1, 1984

By Gavin A. Hunt

In order for mines to operate profitably throughout their life it is important to monitor and maximise ore recovery. A common problem facing many mines is the underestimation of clay type and its distribution in ore at the mine face, blast hole or in the ore stockpile. Too much clay entering the heap leach ore stream for example causes a dramatic reduction in heap leach efficacy and or increased leaching times. The end result is poor leaching performance and much reduced metal production. Poor clay identification and quantification is attributable to many factors, including costly and slow off-site mineral analysis techniques, such as XRD, XRF and petrology, the visual and subjective limitations of the core logging geologist and a lack of suitable low cost, high throughput mineral logging instruments. To get round these problems a new, non-contact, imaging spectrometer - the SpecCam - was developed by Spectra-Map Ltd, to allow high throughput identification and quantification of minerals from mineable material. Its novel imaging design can collect millions of data points (pixels) per day; each pixel contains spectral information that allows a wide variety of mineral types, including the smectite and illite clays, and phyllosilicates such as talc and kaolin, to be identified. Because all the ore can be imaged a much more reliable mineral log can be made. Hence, mapping changes in mineral composition - related to variations in phenocrysts, macrocrysts, veining or wall rock - is possible. Examples of SpecCam data from Goldfields Cerro Corona Porphyry stockpile and from Rio Tinto?s Argyle Diamond mine illustrate the mineral identification and quantification capabilities of the SpecCam. More importantly, for the first time very accurate % abundances for the different minerals can be obtained using an image-based modal count technique. The modular design of the camera, plus its extremely flexible high speed filter, mean that the SpecCam can be easily installed on different equipment, each one suited to different ore recovery problems. For example the SpecCam can be used on an automated portable logging frame to measure drill core, RC chips, hand samples or powder, or alternatively installed on a Geotek multi-sensor core logger for high-throughput, automated logging of drill or blast hole core using co-registered multi-sensor data. An exciting recent development has been the installation of the SpecCam on CommoDas ore sorting equipment, used around the world for 24 hour mill-feed monitoring and automatic ore sorting. Real-time ore sorting decisions can be made as material is monitored on a conveyor belt running at 3m s-1, from which the ore can be automatically sorted into high-grade, low-grade or waste streams for example. The three installation options for the SpecCam mean that most mineral analysis and automated core logging or ore monitoring needs can be met at the mine. For the first time rapid and automatic mineral identification and accurate quantification can be made. All of which allow the mine geologist or metallurgist to make important decisions about maximising the metal recovery process.

May 1, 2007

By K. Shen, A. J. Sinclair, N. Champigny

"Fluid inclusion studies from the Cinola deposit indicate low salinities and low C01 contents of the ore fluid. This supports a suggestion that the mineralizing fluids originated from pore water in the fluviatile host rock (mid-Miocene Skonun Formation). Bimodal distribution of filling temperatures suggests the existence of at least two temperature regimes centred on 160°C and 270°C during mineral deposition. Independent age and stratigraphic evidence indicates that depth of mineralization is between 1.1 and 1. 8 km, corresponding to a hydrostatic load of between 110 and 170 bars.RESUMELes donnees sur les inclusions fluides du gisement Cinola indiquent de basses salinites et basses teneurs en C01 . Ceci confirme que les fluides mineralisants ont ete derives de l'eau interstitielle prise dans les sedimentsfluviatiles hates. La distribution bimodale des temperatures d'homogenisation implique !'existence de deux regimes de temperature concentrees vers 160°C et 270°C pendant Ia mineralisation. La profondeur alaquelle le gisement s'est forme est evaluee d'etre entre 1.1 et 1.8 km a partir d'informations stratigraphiques independantes: ceci correspond a des pressions hydrostatiques de 110 a 170 bars."

Jan 1, 1982

Concentrator Improvements -1990-1995Back to Basics ?pilot plant versus plant opportunities identified ?understand process fundamentals & baseline -1996-2000Point ?C?Projects ?strategy to improve global competitiveness ?structure implemented to generate & drive ideas ?capital investment for life of mine asset renewal - 2001-200?Six Sigma Methodologies ?emphasis on data, measurements & analyses ?dedicated, highly trained personnel on projects 1990-1995 Improvement Phase??Philosophy??back to basics?approach?understand what each piece equipment needed to do?understand reagents, control variables?confirm operating strategies ??probe, stabilize, institutionalize??test theories, confirm with lab and plant trials?process stability (equipment reliability, controls)?enhanced operator guidelines, operator training?focus on continuous improvement?optimize existing equipment capability?stop looking for ?magic?solutions 1990-1995 Improvement Phase??Technical?finer grind, same equipment?optimize media size/shape to grinding application?balanced available ball mill power to applications?lowered cyclone feed densities where possible?improved selectivity, same equipment?balanced available cells to applications?streamlined process (eliminate process steps)?added cleaning stages where required?understanding pulp/mineral surface chemistry?lowered flotation pulp densities 1990-1995 Improvement Phase??Effort?numerous studies to understand process?liberation and mineralogical characterization?pulp and mineral surface chemistry?flotation kinetics and entrainment?extensive internal and external manpower?Brunswick, Noranda Technology Centre?CanMet, AMTEL, MinnovEx, Lakefield Research, McGill University?small capital expenditure

May 1, 2002

By F. N. Smith

Corrosion was observed on the aluminum pressure plates and dress-caps that hold the glazing in place on a curtain-walled building, The multi-storey building in question is situated in the downtown area of a busy Canadian city, For aesthetic reasons, the original design required the dress-caps (which have L-shaped cross-sections) to be externally clad with thin copper sheet. Since the aluminum was in direct contact with the copper trim, galvanic corrosion developed that resulted in damage to the aluminum components, Soluble corrosion products washing off the copper trim may also have contributed to the accelerated corrosion of the aluminum, The aluminum pressure plates and dress-caps are being systematically replaced with components made of fibre-reinforced plastic. The outsides of these new components will be clad with thin copper sheet in order to preserve the original appearance of the building.

Jan 1, 2005

By Nigel Saunders, Zhanli Guo

"Quench sensitivity of heat-treatable aluminium alloys is closely related to the precipitation process taking place during quenching. Faster cooling results in less precipitation of coarse phases during cooling, leaving more solutes in the solution before ageing. An alloy in such state would be of greater hardening potential as larger amounts of hardening phases may precipitate out during ageing. Hence, to understand the quench sensitivity of an alloy, it is essential to understand its precipitation process. Precipitation is a diffusion-controlled process and the diffusion is made complicated by the so-called quenched-in vacancies. These vacancies form during solution treatment, become “excess” when temperature goes down, and annihilate during the following cooling and ageing treatments, making diffusion now a function of both temperature and time. This paper first investigates the formation and annihilation of quenched-in vacancies and their effect on diffusion. The diffusion affected by quenched-in vacancies is considered in the kinetic models to realise the calculation of TTT/CCT diagrams for aluminium alloys. The calculated CCT diagrams have been used to explain the observed quench sensitivity and age hardening behaviour of various commercial alloys. The transformation from GP zones to other hardening phases during ageing is also discussed.INTRODUCTION The heat treatment of aluminium alloys mainly consists of three stages: a solution treatment at an elevated temperature, quenching from this solution treatment temperature to room temperature, followed by an ageing treatment to allow the precipitation of strengthening phases(Davis, 1993).The following statements generally describes how quench sensitivity is observed in heat-treatable Al-alloys: faster cooling results in,(i) less precipitation of coarse phases formed at high temperature during cooling, (ii) more solutes kept in solution before ageing, and (iii) larger amounts of hardening phases being formed, i.e. a greater hardening potential. Thus, the quench sensitivity of an alloy is closely related to its precipitation kinetics."

Jan 1, 2018