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By A. Dolatmoradi

Nanocrystalline structure formations produced by severe plastic deformation in Fe-0.15C with initial ferritic-pearlitic and IF steel with ferritic microstructures have been studied through microstructural observation and microhardness measurements. It was found that the nanocrystalline region first forms near the surface of samples due to localized severe deformation. It was also observed that the nanocrystallization rate of Fe-0.15C and IF steels and the deformed layer thickness in these two materials are different with similar milling conditions. The crystallite size and structural evolution of the samples during milling was studied by employing XRD and SEM.

Jan 1, 2010

By K. Ohto, B. B. Acihikari, H. Kawakita, M. Gurung, S. Alam

Two kinds of adsorbents were prepared from persimmon tannin extract to investigate their adsorption behavior of metal ions from hydrochloric acid solution; one was prepared by treating with concentrated sulfuric acid while another was prepared by immobilizing functional groups of quaternary amine. The former adsorbed only gold(III) and its maximum adsorption capacities was evaluated as high as 1510 g/kg while the latter adsorbed not only gold(III) but also palladium(II) and platinum(IV), the maximum adsorption capacities of which were evaluated as 820, 89 and 101 g/kg, respectively. For both adsorbents, practical adsorption of base metals was not observed.

Jan 1, 2011

By Dale L. McKinnon, Jean-Pierre Farant

"Dust collectors are used to reduce airborne dust levels generated during crushing at a mining operation and their adequate maintenance is required to ensure effective control of health and safety hazards associated with dusty conditions. Although the pitot traverse technique is commonly employed to balance these dust collectors, the use of an alternative-the equilibrium concentration tracer gas method-is proposed in this paper. This method, which uses sulphur hexafluoride as a tracer gas, can be used to balance airflows in dust collectors and to determine hood collection efficiency accurately and effectively. This technique also reduces some of the errors inherent to pitot tube measurements. IntroductionIndustrial dust collectors are used to reduce dust genera ted by processes like cru shin g, and these must be periodically checked and balanced to ensure continuing effective control of health and safety hazards associated with dusty conditions.To date, the pitot tub e traverse technique has been commonly used to balance air flows in dust collectors. However, this technique is both time -consuming and cumbersome. The equilibrium concentration tracer gas method, described in this paper, is proposed as a viable alternative as it is faster, more reliable, and amenable to automation. The use of tracer gases for such task s is not new. This approach has been used in a variety of mining situations to determine volumetric flow rates in underground openings, leak age through mine stoppings, the effectiveness of face ventilation, pollution migration patterns, mine air recirculation rates, and rock porosity."

Jan 1, 1986

By G. W. Diehl, G. A. Griffiths

"Gentlemen, one week ago, I attended the University of Minnesota's Annual Symposium on Mining, in Duluth. A good part of this symposium was dedicated to mill linings of rubber.At this symposium, three mining companies published results from long time full scale tests with rubber linings in mills at four different mines. These were the Republic and Empire Mines of Cleveland Cliffs Iron Company, the Groveland Mine of Hanna Mining Company and the Eagle Mountain Mine of Kaiser Steel Corporation. These papers will be printed in due time and I will not endeavour to relate their full contents, let me only say that in three of the plants, the linings were found to be very economical compared wi.th steel, and that these three are converting over completely to rubber linings, while the fourth, Empire Mine, reported no economical results as far as the shell lining goes, whereas the grates showed promise of becoming economical. The authors of the Cleveland Cliff's paper, however, stated that design improvements in the rubber lining possibly could result in an economical lining also for Empire Mine.That rubber linings in mills, in most cases, show better wear life than steel linings, is known by most of the audience. But, one thing that has not before been disclosed by the endusers is the effect of rubber linings on the grinding economy. All three papers mentioned above reported no change in capacity or grind and two of them reported a decrease in power consumption per ton ground. Hanna Mining reported an average decrease over a three year period for one mill of over 10%. This, of course, puts the economy of a rubber lining in a completely new light. Finally, a point of interest at this meeting was that all three papers emphasized the design aspect, Thus the industry has acknowledged what I believe to be a very important fact - the design of a lining is often more important than the material it is made of."

Jan 1, 1970

By Frank Ebbutt

In this paper it is proposed to point out certain structural factors that; have an important bearing on gold deposition. The subject will be treated; more or less generally. Although the writer has had access to a great many; of Canada's gold mines he does not wish to take the liberty of discussing; details of any particular mine or mines; the aim will be to discuss controls; that are evident in many places.

Jan 1, 1954

By K. C. Corin, M. S. Manono, J. G. Wiese

Depressants play a crucial role in the flotation of PGM bearing ores as they prevent naturally floatable gangue (NFG) from reporting to the concentrate. This action is regarded as critically important because less dilution of the concentrate means lower costs for downstream processes. However, abnormal water conditions (such as high concentrations of ions) in the flotation system can modify the selectivity of these depressants. It is well known that the existence of selected electrolytes in water can alter the behaviour of some polysaccharide depressants by enhancing their adsorption onto gangue minerals and thereby prevent naturally floatable gangue from moving into the froth phase. Concurrently these same electrolytes may enhance frothability, owing to their stabilising effect on the bubbles within the system. Plant water at various ionic strengths was investigated against depressant type and dosage in order to understand electrolyte-depressant interactive effects during the flotation of a Merensky ore, using entrainment, rate of NFG recovery, and total gangue recovery as proxies. The study showed that the rate of NFG recovery per unit mass of water decreased with increasing ionic strength at all dosages, however the total amount of gangue reporting to the concentrate increased with increasing ionic strength at all depressant dosages. Thus, this paper attempts to consider the effects of both ionic strength and depressant dosage as individual factors within flotation. It further looks to investigate whether any interactive effects exists between these two factors when considered simultaneously.

Jan 1, 2016

By A. Welty, T. Garn, K. Lyon, B. Jakovljevic, R. S. Herbst, M. Greenhalgh, Cytec Solvay Group

"Industrial rare earth separation processes utilize PC88A, a phosphonic acid ligand, for solvent extraction separations. The separation factors of the individual rare earths, the equipment requirements, and chemical usage for these flowsheets are well characterized. Alternative ligands such as Cyanex® 572 and the associated flowsheets are being investigated at the pilot scale level to determine if significant enhancements to the current separation processes can be realized. These enhancements could be defined as higher separation factors, reduced stage requirements, or reduced chemical consumption. Any of these enhancements can significantly affect the costs associated with these challenging separation proccesses.A mid/heavy rare earth element (REE) separations flowsheet was developed and tested for each ligand in a 30 stage mixer-settler circuit to compare the separation performance of PC88A and Cyanex® 572. The ligand-metal complex strength of Cyanex® 572 provides efficient extraction of REE while significantly reducing the strip acid requirements. Reductions in chemical consumption have a significant impact on process economics for REE separations. Partitioning results summarized Table 1 indicate that Cyanex® 572 offers the same separation performance as PC88A while reducing acid consumption by 30% in the strip section for the mid/heavy REE separation."

Jan 1, 2016

By D. P. Wilkinson

There are significant global environmental and supply issues with existing energy paths today . Global emission and fuel regulations, global fuel and power structure, energy security, and cost are driving new technology and non-conventional approaches . Fuel cells will play a significant role in the strategy to effect positive global change, increase fuel efficiency and decrease dependency on traditional fossil fuels. Fuel cells do not require recharging, just refuelling and a wide range of fuels are possible with hydrogen being the most desirable. Technical progress as well as investments in fuel cells for transportation, stationary, portable, and micro fuel cell applications have been dramatic in recent years. The present view is very optimistic for fuel cell power generation and the status is presently at the field trial level, or early commercialization stage, moving into volume commercialization. A number of demonstration programs are in progress worldwide such as the California Fuel Cell Partnership which involves original equipment manufacturers (OEMs), fuel providers, transit authorities, state and government bodies. Fuel cells and a hydrogen infrastructure are key to a long-term solution to global energy issues. Fuel cells will need to be competitive on an economic basis with the established and highly developed internal combustion engine and other forms of power generation There has been significant technical progress in a number of fuel cell areas including power density, transient / dynamic response, multiple fuels, cost potential, reliability and durability. However, significant technology gaps still remain today. This presentation will focus on the status and progress of the fuel cell today, current fuel cell research and development, the challenges going forward, and the future view of the fuel cell and it's impact on global energy issues.

Jan 1, 2005

"These guidelines have been prepared to assist the Qualified Person(s)in the planning and supervision of exploration programs which will be reported under National Instrument 43101. The Companion Policy of NI43101 references the guidelines and states that issuers and Qualified Persons should follow them.Exploration Best Practices GuidelinesPreamble: These guidelines have been prepared to assist the Qualified Person(s) in the planning and supervision of exploration programs which will be reported under National Instrument 43-101. Such exploration programs must be under the supervision of the Qualified Person who will be responsible and accountable for the planning, execution and interpretation of all exploration activity as well as the implementation of quality assurance programs and reporting. These guidelines are also recommended for use in the planning and execution of exploration programs which will not be reported under NI 43-101. This set of broad guidelines or ""best practices"" has been drawn up to ensure a consistently high quality of work that will maintain public confidence and assist securities regulators. The guidelines are not intended to inhibit the original thinking or application of new approaches, that are fundamental to successful mineral exploration.Results should be summarized and reported in a Technical Report of good professional quality in accordance with the National Instrument 43-101 and Form 1 contained in that instrument. All exploration work from which public reporting will ensue must be designed and carried out under the supervision of a Qualified Person (""QP""). A QP is defined in National Instrument 43-101 as an individual who is an engineer or geoscientist with at least five (5) years' experience in mineral exploration, mine development, mine operation or project assessment, has experience relevant to the subject matter of the project or report and is a member in good standing of a recognized professional association."

Jan 1, 2003

By George J. Thompson

This pa per deals with the internal characteristics of steel and its response under cold northern temperatures. General maintenance procedures and specific repair techniques are covered.

Jan 1, 1973

By K. M. Ed

MR. J. C. NICHOLSON: The author has discussed his subject in a very thorough manner. One difficulty is the tendency to regard a 'permitted' explosive as a 'safe' explosive. There is no such article as a safe explosive; any explosive is only as safe as the man who handles it. In making up the primer, the method illustrated in the paper is alright for the ordinary explosive but not so for the sheathed explosive, for the sheathing would be punctured. MR. T. L. McCALL: I fee! quite certain that there would be little, if any, trouble from flame shots or misfires if the author's suggestions were carried out. There is a tendency on the part of the shot-firer to over-shoot, so as to bring clown more coal for the miner, and frequently a shot has not sufficient burden imposed upon it. Shooting one hole may not only lessen the burden on an adjacent hole, but may practically release it altogether, in which case the second hole should be fired with a very small charge, or perhaps it might not be necessary to shoot it at all. While the paper refers to shooting in the coal only, it should be under-stood that the instructions given are equally applicable to brushing shots. I do not wish to bring up any contentious point, but would the author say a word on cushioning with air gaps and on multiple shooting? Single shooting in rock might open up a feeder of gas which could be ignited by the ?second shot.

Jan 1, 1940

By A. F. Robertson

FOR several years, the rock-burst question has been given serious consideration by the operating staff at Wright-Hargreaves mine and, as a result of observations and experiences, several different methods of mining have been developed which are now in use in various parts of the mine. These are described in the following pages. It should be emphasized, how-ever, that these methods, and the views expressed in this paper, are based solely on conditions at Wright-Hargreaves mine. Such conditions may or may not be similar to those obtaining in other mines in the Kirkland Lake area, where ore occurrences, veins, wall-rock, faulting, intrusives, etc., may be entirely different. Size and shape of ore-bodies, composition of the ore-bodies and their surrounding rocks, locations of intrusives and sedimentary rocks, and direction, dip, and strength of faults, all introduce problems that are peculiar to each individual mine. Ground failure' in coal and metal mines is not at all unusual. A variety of systems of mining have been developed to delay movement of large or small blocks of ground, or, in some instances, to take advantage of the fact that ground movement, due to mining operations, is unavoidable. Ground failure may be either slow collapse or it may take place with explosive violence. It is principally with the latter condition that we are concerned in the mines of the Kirkland Lake district.

Jan 1, 1939

By G. C. Weatherly, L Beitelman, M Gray, M. W. Bates, R Hadden

"A program of evaluation of in-mould electromagnetic stirring on the product of a straight-mould, billet continuous casting machine has been carried out. The effects on macrostructure, surface and internal quality, chemistry segregation and mechanical properties on carbon, low-alloy and resulphurized, free-machining steel billets and rolled bars are discussed. Operational aspects as a result of in-mould stirring are highlightedIntroductionA development program on electromagnetic stirring (EMS) in the mould of a continuous caster was started by Ferrco Engineering Limited in 1979, with the first experimental device being developed and installed at Lake Ontario Steel Company. As a result of these initial trials, new designs of in-mould EMS systems have been developed and are currently being used in continuous casters in North America and Europe. The rapid progress which has been made is in large measure due to the fruitful cooperation which has existed between the various parties, including Ferrco, the EMS equipment manufacturer, several operating plants and the University of Toronto.A brief review of some of the basic ' principles of electromagnetic stirring action on solidifying metal, and the landmarks of this process development, will explain the philosophy of this cooperation.From casting practice, it is well known that an equiaxed dendritic structure provides better' material properties than a columnar dendritic structure. Homogeneity of the equiaxed structure leads to better control of material properties, such as strength and ductility. Therefore, many efforts are being made to obtain this structure in continuous casting.The extent of the equiaxed zone is determined to a large degree by convective flow in the liquid. Fluid flow can fragment dendrites in the columnar zone, which then act as nuclei for grains in the equiaxed zone farther down the sump. This process is referred to as dendrite or grain multiplication."

Jan 1, 1982

By Marty Hudyma

There are five independent seismic source parameters: seismic energy, seismic moment, source size, location, and time. These parameters are investigated primarily for evaluating seismic hazard and understanding seismic source mechanism(s). Broadly, seismic hazard is the likelihood of occurrence of an event of a given magnitude. Seismic source mechanism is the mode of rockmass failure that causes the seismic event. Most mine seismicity analysis techniques use a combination of a few of the independent source parameters. In literature, time is perhaps the least discussed and most underutilized of these five parameters. This paper discusses three applications of time to understand both seismic hazard and seismic source mechanism in mines. The first application is time history analyses, which focuses on how other parameters of interest vary over time. Examples are presented to show how time history analyses can give information about both seismic hazard and seismic source mechanism. The second application is analysis of time-between-events. This technique can give insight into seismic source mechanism. The final application is phasor analysis using the Schuster test. This method can be used to investigate how seismic source mechanisms may change over time. For both time-between-events analysis and phasor analysis, there are important implications with regards to scale dependence and the breakdown of self-similarity of mining-induced seismicity.

Jun 1, 2012

By G. A. Kosick, M. Freberg, L. A. Kuehn

"Highly variable and higher than forecast lead miff feed grades were problems experienced at the Polaris Concentrator. Limited flotation capacity and poor operating flexibility prevented the plant operators from overcoming these difficulties, and resulted in grades and recoveries which were lower than necessary.Two column cells were integrated into the lead circuit in an effort to give the operators the tools they required to achieve the best grades and recoveries possible, regardless of the miff feed grade. Installation of the column cells increased lead concentrate grade from 76% to 79.3% Pb, and increased lead recovery from 9/% to 91.3% Pb.This paper reviews the design, development and operation of column flotation cells in the lead circuit at the Polaris Mine.IntroductionThe Polaris Concentrator was constructed in 1980 on a barge in Trois Rivieres, Quebec, and towed to its pre sent location on Little Cornwallis Island, Northwest Territories, about 1450 km from the North Pole. The plant presently treat s about 2800 mtpd of new feed with average feed grades of 3010 Pb, 13% Zn and 5% Fe. Current production averages 36 000 tonnes of lead concentrate and 220 000 tonnes of zinc concentrate annually.The barge design and min e location dictated that the concentrator .be compact with very little unused floor space. As a result, flexibility was limited in terms of expanding the plant.Mill feed grades were highly variable and above forecast and the lead flotation circuit was found to be under capacity. This caused continued overloads in the lead cleaning circuit, resulting in low concentrate grades and recoveries. It was evident that an increase in lead flotation capacity and flexibility was necessary. The existing floor space did not allow for the installation of additional conventional flotation cells, but one alternative was the installation of column cells."

Jan 1, 1988

By G. J. Desroches

"In order to improve zinc plant productivity, areas of low efficiency were identified. As a result, solution purification was improved, additional dust precipitator capacity was made available and a new zinc casting plant was installed. The effects of these and other changes are discussed and the expenditure and benefits reviewed. HistoryThe operation of the Flin Flon metallurgical complex including an electrolytic zinc plant commenced in October 1930. The design of the zinc plant was based on that of the Commonwealth Mining and Smelting Company at Trail, British Columbia, the Anaconda Great Falls Montana Plant and the Electrolytic Zinc Company plant at Risdon, Tasmania.The plant began with a design capacity of 60 tons per day and currently produces 255 tons per day. Since plant start-up, approximately 3.5 million ton s of zinc metal have been produced, most of it exceeding special high-grade specifications.IntroductionThe facility incorporates the basic process steps of roasting, leaching, purification, electrowinning and casting. Figure I details the flowsheet. During the late 1970s, management recognized that in order for the zinc plant to continue operating, it was necessary to introduce cost-effective practices.Study groups, consisting of design engineers and operations personnel, were formed to investigate the details of plant revisions.The objectives were to improve productivity by reducing manual labour, reducing energy usage, increasing zinc recovery, increasing metal output and reducing costs.This paper details the changes made during the period 1979to 1986 and shows how these changes have affected the productivity and economics of the zinc plant operation."

Jan 1, 1988

By Marcel Vallée

"Abstract-In recent years, several unsavory events in international mineral exploration, as well as several widely publicized project difficulties and failures have occurred. The report Setting New Standards has "raised the bar" and proclaimed a "commitment to continuous improvement... and change." We need to evolve from our "generally accepted" practices to more effective quality assurance policies, guidelines and standards. Several steps will be required to support the work of the "qualified persons" now wholly entrusted with technical and professional matters:• adopt a mineral development model and objectives appropriate to orient the selection of workmethods and verification procedures suitable to increase the profitability of these activities;• review the definitions and implications of the terms practice, guideline and standard;• review three quality assurance systems with emphasis on commitment of company management and complementary emphasis on systematic quality policies, plans and manuals (ISO 9000), continuous improvement through "profound knowledge" (Deming, 1986), and self-appraisal of continuous improvement and client satisfaction using the Qualimeter Guide (Québec Society for Quality);• determine, from the objectives of the mineral development model proposed and the problems often encountered, the requirements of resource/reserve estimation and the production feasibility study. To regain investors’ confidence and improve the returns from mineral development activities, an explicit commitment to quality by the board of directors and the management of every company is required.A number of mining companies have gained ISO 9002 certification for their operations but exploration companies should start by developing and implementing quality assurance guidelines and standards based on the ISO 9001 pattern, without achieving actual ISO certification in the short term. Both professional associations and industry organizations must be involved in the process of developing the required quality and continuous improvement guidelines and standards."

Jan 1, 1998

By R. B. Smith, D. C. Brady

"A review of the major renovation of the fifty-year old C-I headframe facilities at NERCQ's Con Mine, Yellowknife, N. W.T. is provided. The project was complete with only two 3-day shutdowns of the facility .Work consisted of four major phases: structural reinforcement of the adjoining mill building prior to dismantling; relocation of virtually all mine and mill utilities which transited the headframe collar en route from the adjacent powerhouse; dismantling of the entire headframe facility and portion of the mill building, including the removal of asbestos siding; and erection of a new headframe, idler rower, collarhouse and mill wall.This paper describes the work and methods used by NERCQ, J.S. Redpath Mining Consultants Limited, Acres International Limited, and others to bring the project to a successful completion. The history of the project is discussed from the planning phase through construction, including; design, procurement, and construction scheduling. The paper discusses the unique elements of the project, the problems encountered, and the methods used to achieve success.IntroductionThe Con Mine is a 800 tpd gold operation located in Yellowknife, Northwest Territories. Originally owned and operated by Cominco Limited , the Con Mine was sold in December 1986 to NERCO Minerals Company, and officially renamed NERCO Con Mine, Ltd. The Con Mine has been in operation for over 50 years. The first gold brick ever produced in the Northwest Territories was poured at the Con Mine in 1938. The original C-1 shaft was sunk in 1937 to a depth of 235 ft. In 1941 the shaft was deepened to a depth of 950 ft, and the original timber head frame was replaced with a steel structure. Following the discovery of the Campbell Shear in 1946, the C-l shaft was again deepened to its present depth of 2443 ft. Over the years, mine production gradually moved deeper and further from the C-l shaft."

Jan 1, 1991

By L. C. Galloway, P. M. Tiley

"Some progress has already been made in defining the parameters which will determine the performance of a guidance system in a mine shaft. Very little information is available, however, to help designers or operators predict the effects of varying these parameters in new or existing installations.The experience we have gained from monitoring a variety of installations has led to the development of a model which simulates the motion of a conveyance as it moves through a mineshaft, restrained by fixed guides.This paper presents a general analysis of the performance of the guidance system used in several installations, as well as a detailed description of the problem encountered at one mine and the steps taken to solve it.IntroductionOur company has investigated in some depth the problems that arise in the guidance of mine hoist conveyances.We have a telemetering accelerometer which we obtained to test mine hoist brakes. Frequently, during brake tests, the mine owners request us to use this instrument to measure the lateral motion of the conveyance ""to check guide alignment"". We have made such tests in shafts that have guide s of different kinds, including wooden guides, steel rail s and tubular steel guides. From these tests, we have gained some valuable information about guidance systems.In a well-aligned guidance system that is designed within common and well-known practice, the conveyance will experience very little shock most of the time. However, on rare occasions, shocks up to .5 g will occur. That is, the conveyance exerts a force of up to half its loaded weight on the guide. If the guide slips or is damaged by this force, it will be misaligned for future trips and become the cause of future shocks. In time, the whole guidance system can become misaligned."

Jan 1, 1982

By L. C. Galloway, P. M. Tiley

"Some progress has already been made in defining the parameters which will determine the performance of a guidance system in a mine shaft. Very little information is available, however, to help designers or operators predict the effects of varying these parameters in new or existing installations.The experience we have gained from monitoring a variety of installations has led to the development of a model which simulates the motion of a conveyance as it moves through a mineshaft, restrained by fixed guides.This paper presents a general analysis of the performance of the guidance system used in several installations, as well as a detailed description of the problem encountered at one mine and the steps taken to solve it.IntroductionOur company has investigated in some depth the problems that arise in the guidance of mine hoist conveyances.We have a telemetering accelerometer which we obtained to test mine hoist brakes. Frequently, during brake tests, the mine owners request us to use this instrument to measure the lateral motion of the conveyance ""to check guide alignment"". We have made such tests in shafts that have guide s of different kinds, including wooden guides, steel rail s and tubular steel guides. From these tests, we have gained some valuable information about guidance systems.In a well-aligned guidance system that is designed within common and well-known practice, the conveyance will experience very little shock most of the time. However, on rare occasions, shocks up to .5 g will occur. That is, the conveyance exerts a force of up to half its loaded weight on the guide. If the guide slips or is damaged by this force, it will be misaligned for future trips and become the cause of future shocks. In time, the whole guidance system can become misaligned."

Jan 1, 1982