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By W. L. Hunter

The preparation of coal for the commercial market is a study both varied and wide, and can be viewed from many angles and in different ways. This short paper can but touch upon the subject and is intended to discuss briefly preparation plants which in some cases would seem to be quite inadequate. The conditions confronting most operators are similar, inasmuch as the existing plants were not built specifically to prepare a product for the market of today, but rather of yesterday. The tremendous strides made in the field of combustion in recent years require that the product be of the highest grade procurable, and in a glutted and somewhat restricted market the buyer may be more pernickety than otherwise. These would appear to be the conditions of today. Where a mine is operated individually, better all-round results seem more readily procurable than in a consolidated effort where so many different conditions are sure to arise demanding cognizance, and in many cases requiring to be incorporated in the scheme of things. In the case of a number of mines being administered to form a central source, that source not having had anything to do with the bringing into being of the institutions over which it presides, we find some of the mines well equipped with facilities to properly screen and load the coal, while in others the facilities are not so good, but are doing their share towards delivering a product that will pass muster and in such quantities that they can be counted on.

Jan 1, 1930

By Will Callupe Arzapalo

The success of the minimization of blast induced-damage at Barrick?s Pierina Mine in Peru is the result of an effective working relationship between Mine Operations and the Geotechnical Services Department. A detailed design criteria manual is used to match the blast plan to the site?s varying rock types and slope designs. The Geotechnical Services Department has further developed a comprehensive pre- and post-blast checklist that is critical to the drilling and blasting process as it pertains to wall stability. Wall control blasts are evaluated with quality assurance field checks, vibration monitoring and frequency control, video assisted performance quantification and post excavation face profiling. These detailed observations are compiled and summarized in a blast performance evaluation that is considered to be an ?Industry Best Practice?. The information and detail provided by each performance summary allows accurate blast analysis and effective design refinement.

May 1, 2006

By J. W. Reynolds

Introduction The Sullivan mine, at Kimberley, B.C., is the principal source of ore for the Consolidated Mining and Smelting Company of Canada, Limited. Current production amounts to about 2,500,000 tons of lead-zinc ore a year. With approximately 1,600,000 feet of percussion drilling and 700,000 feet of diamond drilling being carried on each year, any improvements in drilling practice are important. Testing of new equipment and drill bits is a major function of the Testing Department at the mine. Tungsten carbide bits have been the subject of many tests since 1947 and have been used in operations since 1948. This paper details with the methods of testing and gives comparative data on performance and costs for tungsten carbide bits as compared to steel bits. Operational use of tungsten carbide bits started in April, 1948, and the extent of application has increased considerably since that time. The scale of employment is illustrated in Table I, which also shows other statistics on the use of carbide bits. Up to the present time eighteen types of carbide bits or tipped steel, as made by six different manufacturers, have been tested. In general, one supplier's bits have been used in operations, but some large-scale operational tests have been carried out with other types. The types tried are shown in Table II. To date they have been, the subject of 33 tests, covering the destruction of 804 bits over an observed footage of 42,586 feet.

Jan 1, 1951

Ground support audits are sometimes necessary in ageing underground mines. Usually, the purpose of such audits is to assess the state of the ground support in various parts of the mine, identify areas that require attention and establish rehabilitation requirements. In 2005, Brunswick Mine, located in Bathurst, New Brunswick, Canada, completed a comprehensive mine-wide ground support audit. The areas examined included excavations in several mining blocks, as well as ramps, shaft stations, garages, shops, etc., throughout the mine. A vast amount of data was collected over a period of two weeks by multiple auditing teams. The audit was followed by a data digitisation exercise, and the creation of a data management system to store audit results and keep track of subsequent rehabilitation activities as they occur. One aspect of the data management system was the incorporation of a function for reporting on ground rehabilitation progress, along with the capability of updating mine level plans for easy visual presentation of this progress. This article describes the approach implemented at the mine to carry-out the audit, as well as the database constructed to manage the results.

May 1, 2009

By Glenn D. Lyle

As part of an initiative to improve value in mining, CEMI is developing a handbook on best practice in mine design. Various formats were examined, and of these, the wiki was selected as being most suitable. Being web-based, its global reach and capability of being continuously updated allows the wiki to evolve as new knowledge is generated, and to capture the diversity of experience of practitioners in the mining industry. While wikis have many advantages in terms of organizing content and searching, their ability to be edited by users is often seen as a negative characteristic for quality control. To ensure reliability of information content, author attribution, specific authorship models, and a peer review process have been implemented, in addition to the standard version tracking capability of wikis. The first phase of the project concentrates on topics related to underground hard rock mine design. The scope will be expanded to cover other aspects of mining as the project matures. Strategic partnerships with various organizations, such as the CIM, and CANMET, are being formed to provide a wide range of seed material to stimulate growth of the site. www.minedesignwiki.org

May 1, 2011

By P. Cleyle, K. McDermott, M. Hall, C. A. Harris

"This paper describes the implementation of an expert system for monitoring and control of the NO. 4 autogeneous mill and spiral circuits at Wabush Mines.This process control system incorporated the mill operating expertize of Wabush Mines operating personnel and was implemented to improve spiral iron recovery and mill productivity by:1. Continuously monitoring the mill power draw and ensuring that the mill feedrate is regulated to prevent damage to the mill motor, while simultaneously maintaining the feedrate at or as close as possible to the maximum feedrate determined by the process supervisor.2. Improving control over the spiral density and feed rate.3. Improving control over both tbe rougher and cleaner wash water.4. Reducing the frequency with which pumps are plugged.5. Allowing modifications to be made easily and quickly to test various operating strategies.This system was installed using COMDALE/C, a real-time Expert System for Process Control. It was readily accepted by the process operators and produces higher production performance in comparison to the other 5 parallel mill lines at a lower power draw."

Jan 1, 1992

By T. Nyabeze

This paper presents the experiences and views of women involved in the mining industry as determined from a questionnaire that was circulated across the Canadian mining industry. Globally, there have been significant studies done to understand the historic and global variety of women?s participation in this industry1. The reason for focusing on women?s experiences here in Canada is because women?s percentage representation at 14.4% in the mineral industry workforce falls below the overall labour force average of 47.4%2. Notably, a recent article in the Globe and Mail newspaper points out that adequate representation of women in leading of organizations is more of a matter of competitiveness and innovation rather than purely a ?women?s issue?3. This paper will provide some insight into the reasons why women join and stay in the mining industry and shed some light into the reasons for the overall low representation in this sector. The authors believe, as stated in a study from the London Business School, that a gender-balanced workforce is one way of providing the best results in areas that drive innovation4. Women represent a key stakeholder group that can help enhance the mining industry?s sustainability through innovation. The women who responded to the questionnaire represent many different areas within the mining industry, including a broad range of roles in industry, government, academia and in the supplies and services sector. The paper is intended to raise awareness about issues that women encounter that contribute or detract from career satisfaction in the mining industry. The survey provides an overall understanding of why women pursue or work in mining, and why women either remain or choose to leave it. The advantages and disadvantages experienced by women are highlighted, along with a summary of the possible initiatives that could be undertaken by employers as opportunities to improve the attraction of the mining industry for career minded women. As well, the survey provides a summary of the top ten features that are already in place at various organizations and community groups that have been identified as key for supporting and encouraging women to join and remain in the industry. Not surprisingly, the survey identifies that one of the key ingredients for retention of women in mining is the provision of mentors and sponsors. Another key aspect for retention is the provision of progressive employment policies that address the need for a degree of flexibility in work hours and a culture of balance between work and personal life demands. The survey and results are portrayed only from a female perspective since it is largely women?s perceptions that will inevitably be transmitted to others who plan on entering the field.

Oct 1, 2010

By Steve W. Ciccone

The Red Dog Mine is both the largest known zinc reserve and the largest zinc producer in the world. The mine started in 1989, and by 1999 had increased production from approximately 300,000 tonnes per year (t/yr) of zinc concentrate to in excess of 900,000 t/yr. The VIP Mill Optimization Project further increased zinc concentrate production to 1.1M t/yr while improving both product quality and zinc recovery. The Mill Optimization project also addressed a number of issues related to risk reduction: power generation capacity, water treatment capacity and concentrate thickening. The project was faced with numerous challenges, the most daunting of which was the schedule. This US$105M project was executed, from conception to completion, inside of two years. Less than nine months elapsed from concept to delivery of materials and equipment to site. The project also faced a 100-day icefree shipping window, the challenges of construction in an Arctic environment, and an extremely tight labour market for qualified craft personnel. These challenges were successfully addressed with several innovative approaches to project execution, including an Alliance contracting arrangement between the owner, engineer and contractor; full integration of the team; construction of modules in Anchorage; and fast-track engineering, procurement and construction. Steve Ciccone, AMEC?s project manager on the Mill Optimization project, works for the Mining & Metals unit of AMEC, a world leader in the provision of engineering and construction services. He obtained his BASc from the University of British Columbia and is currently midway through his MBA program at Simon Fraser University. Steve has 15 years of experience providing engineering and project management services on mining and metals projects, and has been involved in the execution of five capital projects and several studies at Red Dog since 1995. George Hope was responsible for process design and engineering on the Mill Optimization project and has been Manager, Project Development at Teck Cominco since 1995. Prior to this time, he was a project manager and chief metallurgist for Lac Minerals for 14 years and a mill superintendent and metallurgist for Noranda for 5 years. George received his BSc in Mineral Technology from the Royal School of Mines in England.

May 1, 2002

By T. W. Wloder

During recent studies concerning the effects that various surface treatments, surface imperfections, locked-in residual stresses and metallurgical and geometrical notches have upon the mechanical behaviour of metals and, in particular, upon their tension-bending characteristics under impact loads, it became apparent that specially developed methods and samples would be of great assistance in determining the desired data. This paper describes and discusses a number of different types of double-notched tension-bending impact samples which have been considered and examined for this purpose. The types most suitable for exploratory investigations are proposed for application in the study of the _behaviour of metals, their welds, and, in particular, their surfaces, when subjected to various notch-severities, surface imperfections, strain rates, temperatures, and constrained states of stress (i.e. the relations of the three principal stresses). It is expected that the proposed double-notched tension-bending samples and the proposed test methods will also contribute toward further understanding of the cold brittle behaviour and the notch-sensitivities of metals. The possibilities of introducing the so-called impact notch-sensitivity index and relative impact notch sensitivity of metals are discussed. Data obtained on double-

Jan 1, 1961

By H. Bouzahzah

Sulfidic tailings, subjected to atmospheric water and oxygen action, can generate acid mine drainage (AMD); which is the most important environmental problem facing the mining industry. AMD generating potential can be assessed by the static tests which consist of a screening method where the neutralization potential (NP) and the acid-generating potential (AP) of a given rock sample are determined. The AP and NP are determined separately in the different static test existing procedures which can be divided into two distinct classes: chemical and the mineralogical methods. For some chemical method, the AP is calculated on the basis of total sulfide sulfur content in the sample which may overestimate its AP if significant quantities of non-sulfide sulfur species are present (e.g. organic S in coals, some sulfate as gypsum, barite, etc.). However, the mineralogical method evaluates the AP by the sum of the individual sulfides participation on acid generation based on their concentration within the sample and can be more accurate than the chemical method. For AP calculation, the Paktunc (1999a) mineralogical static test takes into consideration all sulfide minerals occurring in the sample. However, it does not take into account the rates of acidity production of these sulfides submitted to weathering conditions. So, the present study focusses on the modification of Paktunc AP calculation by considering the acidity production rates of these minerals. To reach this objective, five base-metal sulfides (pyrite as reference, chalcopyrite, sphalerite, arsenopyrite, galena), diluted within quartz (25?75 wt.%) simulating mill tailings were subjected to a kinetic test to evaluate their AP. The results show that all the studied sulfides minerals generate acidity at different rates, so the Paktunc?s equation for AP calculation has been adapted accordingly.

Aug 1, 2013

By M. Pekguleryuz, S. A. Argyropoulos

"The recovery of additions in light metals is an important parameter influencing consistency of the finished product, which ultimately means cost. Recovery is a function of many parameters such as assimilation speed, addition density, addition practice, liquid metal processing conditions, etc. In liquid metal processing operations, it is desirable to have the maximum possible recovery at the shortest possible time.In this paper a new index will be presented, namely, the rate of recovery (RR). This index quantifies the addition recovery and introduces the time dimension in the recovery increase. As such, the RR equips the liquid metal practitioner with an accurate picture of addition assimilation in liquid metals. Results will be presented on how this index is applied to a variety of additions in liquid aluminum. IntroductionThe data on addition assimilation kinetics offer a valuable parameter describing how fast a given addition enters the metal bath. These data may be expressed as gr m-2 s-1 of additive for a set of experimental conditions which might include bath temperature and degree of bath agitation among others. However, the liquid metal processing practitioner is more interested in the recovery of additions. In other words, the point of interest is the percentage of the used addition entering the metal bath. Ideally, the addition recovery can reach the 100% level. However, in practice, the addition recovery never or rarely reaches that level. Many factors can contribute to this. Some of these factors can be slow assimilation kinetics, addition density, addition practice, turbulence of the melt, etc. In some cases, sloppy addition practices can contribute to low recoveries, or even worse, to erratic recoveries.In this paper a new parameter is introduced. This parameter relates the maximum addition recovery observed over the time needed to achieve this maximum recovery."

Jan 1, 2002

By L. E. Djingheuzian

IN 1953, Lewis (1) published an article which brought forth a great amount of discussion by grinding engineers. In his contribution to discussion the present writer (2) suggested that, for the most efficient performance of a ball mill, there must be a .definite relationship between Cn, per cent critical speed, and V p, per cent mill volume occupied by the ball charge. Later, he ( 3) was able to publish some grinding data from Wright-Hargreaves milly which appeared to bear out this contention. It is with this view to establishing a fundamental relationship between Cn and Vp that the idea of this Forum was conceived. Accordingly, a questionnaire was prepared and copies of it were mailed to over eighty Canadian mill operators. This questionnaire did not include a question on dilution on the assumption that each mill operator was using the most efficient dilution for his operation, nor was a question on efficiency of classification included since it was thought that the inclusion of efficiency of dassification in the questionnaire at this preliminary stage might render the forum discussion,. while everybody was trying to find his bearings, too unwieldy. However, it is evident that, as discussions develop, this forum will have to define a uniform method for establishing most efficient classification in grinding circuits

Jan 1, 1957

By Oyku Selimoglu

The key to successful mine production plan and subsequent operation is efficient mine layout design and optimization. Pit layout design and optimization allow the delineation and extraction of mineable reserves and the minimum waste subject to slope stability, economic, quality and quantity constraints. Many design and optimization software packages have been developed to aid this intensive and challenging process. These packages include VULCAN, SURPAC, DATAMINE, GEMCOM, MICROLYNX, MEDSYSTEM and MINESIGHT. These software packages are developed as integrated computer-aided systems used for database creation, survey, geological and geostatistical modeling, mine planning and production optimization and environmental modeling. In Turkey, many mining companies still plan and design mine layouts with traditional hand methods. In this study, VULCAN has been used to design and optimize the Eti-Bor A.S. Kestelek Boran Open Pit Mine in Western Turkey. The main objective is to show the company the superior advantages of mine planning software for designing and optimizing mine layouts over the traditional hand methods. Drill hole data used by the company to estimate the reserves for planning are used in this study. The ore grade varies between %1,04 B2O3 to %47,33 B2O3. The pit toe and crest strings are projected using variable batter angles and berm distances. On the north side, batter angle is 180 and berm distance is 25 meters, on the south side, batter angle is 320 and berm distance is 15 meters. In addition to that open pit bench height is 10 meter. The concepts of block modeling are applied to the Kestelek open pit mine with detailed ore grade modeling for each block. The Lerchs-Grossmann?s algorithm is used to optimize this mine based on the block model, the economic block values for each block and the underlying field constraints. The results from VULCAN were similar to the estimates by hand. The reserve estimates from VULCAN is 13,192,870 tons compared with the hand estimate of 13,200,000 tons, overburden estimates of 15,622,889 m3 compared with 15,000,000m3 obtained by hand with a stripping ratio 1.18:1 (m3:ton) from VULCAN versus 1.14:1 (m3:ton) from hand estimate. Vulcan improves the efficiency, speed and reproducibility of the planning results. It provides mining engineers, geologists and surveyors with a cost-effective modular system for assessing and planning the mine layouts. Furthermore, Vulcan?s specific modules allow efficient access and manipulation of databases, open pit mine design, block models, optimized 3D mine layouts, and more. However, for competitive business in Eastern Europe, VULCAN should improve its software support. Effective training, help desk support systems and nearby distributors with just-in-time solutions to company problems will generate competitive business for VULCAN.

May 1, 2007

By Maureen E. Lipkewich

Education builds long term awareness, acceptance and support for responsible mineral resource development. The MABC Education Program is an award winning education partnership with British Columbia classroom teachers that has helped over 5400 teachers with resources and other learning opportunities. Each year, thousands of students begin, and continue, to learn about our modern mineral industry as a result of this teacher-written program. The CIM network has an integral role in the future of mineral education in today?s classrooms in Canada and programs of this caliber are vital to our future. The industry needs help in raising awareness of the benefits of modern mining and teachers need help in acquiring that information.

May 1, 2002

By Youjun Tao

Falcon centrifugal gravity separation tests were conducted to study desulfurization and de-ashing performance with different size fractions of a high-sulfur Chinese -0.5mm fine coal in a dense medium. Performance indicators such as combustible recovery, ash and sulfur rejection, and desulfurization efficiency were used to evaluate the separation efficiency. The results show that for -0.5 mm coal particles, all performance indicators except ash rejection are higher for the Falcon concentrator than for flotation. More specifically, for the +0.125 mm size fraction, Falcon centrifugal separation produced better ash and sulfur rejection performance than froth flotation. However, the Falcon concentrator also showed higher combustible recovery but lower ash and sulfur rejection than froth flotation for the -0.125 mm size fraction.

Aug 1, 2013

By A R. Bullis

Metal Mines Limited (Bancroft Division) was incorporated m 1964 to take over the assets of Faraday Uranium Mines Ltd., including their uranium deposit near Bancroft. Ontario. This paper outlines the geology of the Bancroft area, and. then go on to describe the principle rock types m the mine workings, especially the pegmatite, which is the host rock for the uranium mineralization. The structure and mineralogy of the orebodies are thoroughly covered, and, after a summary of the production and ore re-serve figures, the paper concludes with suggestions for further exploration work. Location and History M ETAL Mines Limited, Bancroft Division, is located in Faraday township, Hastings county, Ontario. The main production shaft and concentrator are about: Y2 mile north of Highway 28 and about 5 miles west of the village of Bancroft (Figure 1). The presence of radioactive minerals in the Ban-croft-Wilberforce area has been known since the early 1920's. Uraninite was found at the Richardson deposit near Wilberforce in 1922, and some attempts were made to produce radium from the deposits of the area between 1929 and 1931.

Jan 1, 1965

By T. R. Roy

"This paper presents an objective model for the estimation of fire risk potential of an underground coal mine panel by the bord-and-pillar method of mining where extraction is carried out by depillaring with caving. The fire risk rating procedure for the estimation of fire risk potential involved in the panel is described in detail. The model developed thereof is tested with the field data collected from different collieries across the country along with the laboratory data for critical assessment of fitness of the model. Some results showing the validity of the model are also cited here. Introduction The occurrence of fire in underground coal mine panels is quite common in India and elsewhere. These fires cause extensive loss of resources.Although substantial work has already been done by different research organizations, the problem has not been fully eliminated.The causes of panel fires depend not only on the spontaneous heating susceptibility of coal, but also on the extraneous conditions created in the panel due to the mining operations. From the studies done so far by various organizations, it is apparent that two types of parameters associated with spontaneous heating of a coal mine panel exist: intrinsic and extrinsic. Parameters related to the nature of coal, i.e., its physicochemical characteristics, petrographic distribution and mineral make-up are intrinsic, while the extrinsic parameters are related to the atmospheric, geological and mining conditions such as scope of leakage of air into the panel, wetness of mines, heat dissipation capacity of the panel, gassiness of seam, geological disturbances, method of extraction, size of panel, etc.Banerjee (1982) identified twenty-two mine parameters such as spontaneous heating susceptibility of coal, method of mining, geological disturbances, quality of overburden, degree of consolidation of coal mass, scope of accumulation of coal fines, etc. that can influence spontaneous heating in underground mines. He used the terms “high” and “low” for fire risk rating of each of these parameters. Since this approach is oversimplified, it can not determine the exact fire risk potential of an underground working."

Jan 1, 2003

By B. Krysa, J. Qiu

The zinc pressure leach plant at HBM&S's operations is now in its fifteenth year of operation. Current pressure leach operation is steady at a concentrate processing rate of around 26.5 tonnes per hour. A new cellhouse with a design capacity of 124,000 tonnes per annum and the capability of expansion of up to 154,000 tonnes per annum was commissioned in July 2001. The potential to expand the capacity of the pressure leach circuit and associated processes, as well as the purification circuit and casting plant, to meet the maximum capacity of the cellhouse has been investigated. This paper reviews current operation of the zinc plant, as well as the possibility of a capacity increase without major process modifications or major capital expenditures.

Jan 1, 2008

By D. K. Matlock, D. J. Hamre, J. G. Speer

Ultrafine ferrite (UFF) grains may be produced in surface layers of plate steels using controlled intermediate cooling followed by deformation. Experiments were conducted using a 0.12 C - 1.26 Mn steel on a Gleeble 1500 hot deformation simulator. Taguchi designed experiments were used to evaluate prior austenite grain size, intermediate cooling rate, intermediate cooling temperature, intermediate hold time and amount of reduction in order to observe the effects of variables and their interactions on the final microstructure while minimizing the number of required test runs. Evaluation of resulting microstructures and mechanical properties revealed a preferred thermal and mechanical history for developing ultrafine microstructures in surface layers of plate steels. Application of the fundamental concepts of phase transformations to industrial plate rolling is considered.

Jan 1, 2004

By F Kelly

"A central composite experimental design was used to determine empirical relationships between the operating variables of a ball mill and the characteristics of the ground products. The independent variables selected for the study were the work index and size distribution of the feed material, the feed rate and the pulp density. The measured responses included product size distribution, product surface area, viscosity of pulp discharge, weight of dry solids in mill, mill time constant and emitted sonic vibrations. The ball mill was operated continuously in open circuit during each experimental run.Multivariable regression techniques were used to derive linear empirical models from the experimental results. Of the four factors studied, the grindability of the feed material significantly affected every measured response. The size distribution of the ground product was affected significantly by the feed rate and the size distribution of the feed, but not by the pulp• density. Feed throughput capacity and pulp density were significant to the viscosity of the pulp discharge, the weight of solids in the mill and the mill time constant. Significant first-and second-order models are given for the above relationships. The relation-ships between the characteristics of the sonic vibrations of the operating mill and the various dependent variables have not as yet been established."

Jan 1, 1970