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By B. Jakovljevic, M. D. Soderstrom, T. McCallum, A. J. Quilodrán

Cytec has developed a new organophosphorus based solvent extraction (SX) reagent for rare earth separations. The new product, CYANEX® 572, has been formulated to allow efficient extraction while minimizing the strip acid requirements. The optimization of formulation strength is expected to significantly reduce the operating costs of these circuits. Modeling capabilities for CYANEX® 572 (similar to those used successfully in Cu and Co/Ni SX) have also been developed to aid in the design and optimization of the SX circuits. Simulations will be shown comparing CYANEX® 572 to a traditional rare earth extractant.

Jan 1, 2014

By Michael J. Sapko, Ellsworth R. Spencer, Frank J. Perzak

"The fire resistance of several mine conveyor belts is evaluated using a new belt-flammability apparatus developed by the U.S. Bureau of Mines. The test apparatus, experimental details and a calculated flammability index (FI) are described.The FI values are useful for ranking the fir e resistance of mine conveyor belts. Values are determined using parameters readily measured with thermocouples, high-temperature flow probes and a methane-oxygen torch, all of which are components of the Bureau's new test apparatus. The FI varies directly with the flame-spread rate and the rate of heat release during burning and varies inversely with the critical (minimum) ignitor energy output.The fire-resistance ranking of nine different belt types using this moderately scaled apparatus is compared with available full-scale data on belt fires. This comparison shows that the ranking based on the FI is consistent with the full-scale data.IntroductionFull-scale fire hazard evaluations of mine conveyor belts are not easily related to the properties usually measured in small-scale flammability tests. The inadequacy of small-scale belt fire tests has been demonstrated in works by Mitchell, Warner and Reinke.Mitchell and Warner showed that certain neoprene (NP) and polyvinyl chloride (PVC) belts, which had been approved by the Code of Federal Regulations 30 CFR 18.65, were nevertheless capable of propagating flame over their entire length when full-scale fire conditions were simulated. Comparable results were also observed by Reinke at the Tremonia experimental mine in Dortmund, West Germany, where all belts burned in full-scale tests even though they passed the small-scale tests. Only by reducing the severity of the full-scale test could these fire-resistant belts be grouped on a pass-fail basis."

Jan 1, 1982

By P. Amelunxen, E. Herrera, L. Hill, J. Vanderbeek

It is well-known that the particle breakage mode that occurs in a semi-autogenous mill is significantly different from that which occurs in a ball mill, enough so to warrant very different lab scale breakage tests and scale-up models. This phenomenon, at the plant scale, leads to changing process constraints depending on the particular properties of the ore. For example, hard or coarse ores might bottleneck the SAG/AG mill throughput, while the ball mills might constrain throughput when milling soft or fine ores. Because the power draw of a ball mill is fairly constant compared to that of a SAG/AG mill, periods of SAG/AG mill bottlenecks lead to increased ball mill circuit specific energy consumption and a finer grinding circuit product size, which together constitute a loss of efficiency of the overall process. Because HPGR circuit throughput is less sensitive to changes in ore hardness, this situation is less common or severe in those circuits. Furthermore, the ball mills are somewhat decoupled from the upstream crushing circuits through the use of surge bins, which also helps to mitigate this effect. As a result, ore hardness variability constitutes a significant cost penalty that should be applied to SAG mill/ball mill/pebble crusher SABC circuits when evaluating the relative economics of different grinding circuit configurations. Nevertheless, the issue is by-and-large ignored, because most current HPGR trade-off studies are based on averaged ore hardness parameters. This paper provides an estimate of the magnitude of this penalty for a typical operation by using Monte Carlo simulation methods and plant data from Freeport-McMoRan’s autogenous, semi-autogenous, and HPGR-based comminution circuits. A case study from an in-house 96K t/d sulphide project is presented to illustrate the concept. It was found that by including variability effects, the trade-off NPV of the HPGR circuit over that of the SAG mill circuit increases to $84 million from negative $33 million, effectively reversing the original decision of selecting a SAG mill circuit for the fixed hardness case.

Jan 1, 2012

By R. R. Potter

"IntroductionAlthough iron formations were recognized in western New Brunswick about 1820, commercial production was not achieved until 1848. The Jacksonville deposits near Wood stock were developed first, and ore was treated at a blast furnace constructed 5 km to the southeast on the Saint John River. Several charcoal burners were also constructed. Pig iron was produced sporadically until 1884, when operations were finally suspended. There was little further interest in the area until 1953, when Stratmat Ltd. initiated an ambitious exploration program. At the same time, the company carried out research on an electric-reduction process to produce metallic iron and ferromanganese. The technical feasibility of this process (Udy process) was confirmed, however the high energy costs were prohibitive and work ceased in 1957. Some metallurgical research was carried out by Mandate Refining Ltd. about 1970 and more recently by the New Brunswick Research and Productivity Council.The Years Prior to 1848New Brunswick became a separate province in 1784, shortly after the influx of a large number of Loyalists from the United States. Man y of these people sett led along the Saint John River, including the area of excellent farmland near the present town of Woodstock.There were indication s that some of these earl y settlers recognized iron formations in the vicinity of Woodstock about 1820, however the nature of the deposits was not known until 836 when Dr. C.T. Jackson, a geologist commissioned by the Stat e of Maine, investigated the mineral potential of the area. Jackson (1836) described the ""ore"" as compact red hematite yielding 44 per cent pure metallic iron, and suggested that sizable tonnages may be present. It was about this time that an extensive limonite deposit was found in north-central Maine, near Mt. Katahdin. Other iron deposits were found in the Nictaux area of Nova Scotia, and a few years later at Londonderry."

Jan 1, 1983

By Y. Mitani, H. Ikemi, K. Kitamura, H. Honda

"Instead of carbon capture and geological storage (CCS) that does not rely on structural aquifers, injecting carbon dioxide into sedimentary rock deep underground has been considered. For advection velocity of the fluid is slow, the permeability of sedimentary rock deep underground is low. In order to perform the CCS on the low permeable sedimentary rock, it is necessary to clarify the behavior of long term storage properties of carbon dioxide (CO2).In this study, the permeability and storativity of CO2 injected into low permeable rock has been evaluated. The injection of supercritical CO2 has been conducted on the specimen of Ainoura sandstone (unit weight: 2.39 g/cm3, porosity: 11.9 %) saturated with water by using flow pump method. The experiment has been set up to reproduce the similar condition of deep underground reservoir under 20 MPa confining pressure, 10 MPa pore pressure, 35°C temperature and 3 µl/min CO2 injection rate. In order to prevent an increase in pore pressure, the boundary condition on the outlet side of specimen has been kept a constant pressure.As a result, it has been possible to observe step by step the change of the differential pressure between both ends of specimen. Furthermore, the relative permeability and specific storage of rock under supercritical CO2 injection has been examined by the theoretical analysis of flow pump permeability test incorporating Darcy’s law for two-phase flow. It is observed that CO2 has been transmitted gradually while CO2 stored in the rock. It is also clarified that residual water has existed in specimen after showing the constant differential pressure in the end of the experiment. Using the results of the experiment, 3D core-scale flow-simulation by using TOUGH2 has been conducted due to confirm the flow of fluid and CO2 distribution in the specimen. From the experimental results and analytical solution to them, permeability and storativity are identified, and simulation results support the validity of the experimental results."

Jan 1, 2015

By E. L. Day

"In the early 1930s during the course of test work with a simple gold ore, it was evident that the time required to dissolve the gold by cyanidation was very much longer than should have been needed theoretically for the maximum size gold particles in the ore, A similar conclusion appeared to be valid for other gold ores. In a cyanidation system there are many factors which can influence the dissolution rate of gold, and a decision was made to investigate the more obvious variables, because a literature survey at the time showed that with the exception of the work of Yamazarki on the dissolution of silver in cyanide solution, virtually no attention had been given to this subject, Our work was not reported because the intention was to do this on completion of the Study, but owing to the demands on the Section's personnel for other work the investigation was never completed. Although other investigators have since studied the problem, the methods which we adopted and some of the conclusions may be of interest to metallurgists concerned with gold ore treatment.Form of GoldExperiments with gold ores were not possible because of the number of uncontrollable variables present in a gold ore-cyanidation system, therefore pure metal and reagents were used. Initially some experiments were carried out with gold leaf, but it was soon apparent that metal in this form was unsuitable because the uneven thickness of the leaf caused it to break up into pieces and. there was difficulty in determining precisely when complete dissolution had taken place, Numerous factors both expected and unexpected were found to influence considerably the results and much experimental work was necessary to establish the procedures which were finally adopted, Experiments were carried out with gold in the form of foil, wire, rings and sols. Finally, gold foil in the form of cylinders was adopted for most of the experiments although some work with gold in the sol form was included in the programme. Also some experin1ents were carried out with a gold ore to see if effects which were obtained with sodium chloride on gold sols were applicable to gold ores."

Jan 1, 1967

By J. E. Hawley

"The property of Francoeur Gold Mines, Limited, lies directly west of the Armfield mine in Beauchastel township, Abitibi district, and 12 miles west and slightly south of Noranda. The gold deposits are of particular interest because of their replacement character and close association with fault zones. The property was originally staked in 1923 following the discovery oi a mineralized zone near the eastern boundary. This became No. 1 orebody. Later discoveries in 1936 of No. 2 and No. 3 orebodies led to underground development and actual mining in July, 1938. A fourth orebody, No. 8, was found in 1939.The following is the production record up to December 31st, 1947:Beginning in September, 1944, ore was shipped to Noranda as siliceous flux, but late in 1946 milling of low-silica ore from No. 1 orebody was undertaken until operations were temporarily suspended in 1947.The four main ore deposits, Nos. 1, 2, 3, and 8, consist of siliceous ferrocarbonate and albite replacement bodies mineralized with fine pyrite and specularite in schistose fault zones in Keewatin volcanics. Barren to low grade quartz veins though present in some are uncommon, but small stringers of quartz are usually present wherever here and there visible gold is found. Nos. 1, 2, and 3 deposits lie in a major fault zone that extends completely across the property from west to east (over 7,000 feet) and dips N.40° to 50°, and are separated by intervals of 1,800 to 2,000 feet respectively. The fourth lies in a smaller fault zone striking east and dipping on the average 65°S.No. 1 orebody has been explored by mining to a depth of 500 feet, No. 2 to 400 feet, and No. 3 to slightly less than 300 feet . The greater part of No. 8 lies above a depth of 200 feet, but a raise has recently .been driven through from the west end of the 5th level of No. 1 to the 2nd level on No. 8 zone. Most of the ore of No. 8 zone above the 2nd level and of Nos. 2 and 3 above the 3rd levels has been removed."

Jan 1, 1954

By H. Fujihara, K. Uesugi, H. Toda, A. Takeuchi, K. Shimizu

"Hydrogen is trapped at a variety of microstructures, for example grain boundaries, dislocations and particles. It is thought that hydrogen trapped at trapping sites is redistributed to the other sites under loading and then brittle fracture occurs with hydrogen accumulation. In order to understand hydrogen embrittlement behavior, it is necessary to investigate the time evolution behavior of hydrogen accumulation at each trap site. In the present study, changes in hydrogen distribution are observed under stress using Kelvin force microscopy (KFM) that can visualize hydrogen concentration distribution on material surface at high resolution. Spot-like hydrogen enriched regions are observed on the surface of a material. In addition, hydrogen depleted regions are observed around those enriched regions, and the appearance of hydrogen trap due to particles existing near the material surface is revealed. On the other hand, hydrogen trapped at grain boundary can be visualized. From in this result, it was suggested that crystallographic factors influence hydrogen accumulation. The relationship between initiation and propagation of intergranular crack and hydrogen accumulation under stress will be discussed.INTRODUCTIONHydrogen present in a metal sometimes has significant effects on various properties. Hydrogen in a metal is trapped at a variety of microstructure, for example dislocations and grain boundaries. Grain boundaries, dislocations and micro pores are the major trap sites in aluminum alloys. Some researchers considered that hydrogen redistribution and accumulation between these trap sites in a material with loading plays an important role in the brittle fracture behavior. In general, in intergranular fracture and quasi-cleavage fracture, the hydrogen trapped at grain boundaries and dislocations contributes to fracture behavior, respectively. Recently some researchers have shown that the ductile fracture in aluminum alloys is resulted from growth and coalescence of hydrogen micro pores. Analysis using first principles calculation indicates that intergranular fracture occurs when hydrogen concentration reaches 20 atom H/nm2ongrain boundary. From this report, it is considered that hydrogen redistributed during deformation accumulates locally in order to cause hydrogen brittle fracture. In order to understand hydrogen embrittlement, it is necessary to investigate the time evolution behavior of hydrogen accumulation at each trap site. In the present study, we evaluate the relationship between hydrogen accumulation behavior and fracture behavior in Al-Zn-Mg based alloys. In-situ observation was made by combining the tensile test with Kelvin force microscope (KFM) that can visualize the hydrogen concentration distribution on the material surface with high resolution. We also investigate the relationship between hydrogen distribution behavior and crystal orientation."

Jan 1, 2018

By Marcel M. Djivre

The paper will outline the destructive test methods and test procedures including the evaluation criteria currently used at the Materials Testing Laboratory (MTL), Sudbury, Ontario, Canada, a laboratory approved by the Ontario Minister of Labour for the purpose of testing or examining mine shaft ropes or other hoisting appliances. For the evaluation of the mechanical properties of rope samples used in "ultra-deep" single-lift shafts, additional discard criteria used in Ontario, Quebec and South Africa shall be presented. Most of the methods and test procedures currently used at MTL can also be found in the current CSA G4-00 Standard, Steel Wire Rope for General Purpose and for Mine Hoisting and Mine Haulage, published in November 2000. In this latest or sixth edition of CSA Standard G4-00, a new Clause 14 has been added outlining the requirements for in-service destructive testing of steel wire ropes for mine hoisting applications. The CSA G4-00 Standard is also intended for the manufacturing of new ropes, and includes requirements for raw materials and construction features for round strand and flattened strand rope, and locked coil rope in bright and galvanized finish. To-date the Ontario Mining Regulations require only that destructive test of new ropes be performed in accordance with CSA Standard G4-00, but does not require conformity to the Standard, and on the other hand the inservice wire ropes are required to be tested in accordance with CSA G4 and thus require conformity. The author recommends that the Ontario Mining Regulations (and regulations of other mining jurisdictions) be improved in order to ensure quality control in the manufacturing of wire ropes destined for mines in Ontario (and Canada). Also, the author recommends the revision of the CSA G4-00 Standard by the technical committee in order to address manufacturer?s concerns with respect to compliance, and harmonize the Standard with Internationally recognized Standards.

Apr 1, 2005

By Gene O. Cowie

"Zinc, which once enjoyed an unchallenged position in the field of decorative applications, has lost a substantial share of its markets to other materials, particularly plastics. This turn of events has led the zinc industry to explore new market areas, particularly those applications where the engineering properties of zinc can be utilized. This paper gives an overview of the zinc industry's efforts to develop the data base and product development technology which have enabled zinc alloys to emerge as engineering materials. It also indicates those areas in which the research facilities of the zinc industry must be employed to ensure that zinc alloys keep pace with developments in competitive materials and processes.The Materials RevolutionThe development and utilization of new materials and manufacturing processes progressed for centuries by evolution. Recently it erupted into a revolution, which may become as significant as the industrial revolution. The materials revolution has impacted upon many industries, but none has been affected more traumatically than the North American automotive industry. The plight of that industry is of great importance to us because their problems have, to a great degree, become problems to the zinc industry.Much of the impetus behind the automotive trauma came from the battery of motor vehicle regulations promulgated by the United States government in the 1970s. These regulations required that the efficiency of passenger cars, in terms of miles per gallon, be approximately doubled in ten years. In view of the fact that major changes in the automotive world require three years of lead time to implement, the industry was left with only seven years to perform the task. The automotive industry was simultaneously required to make progress in other areas, such as reduced emissions, reduced cost of repairs and increased levels of occupant safety. These added demands not only diverted some of the available resources away from efficiency goals, they often ran in direct conflict. For example, when you are required to provide a front bumper which will absorb the energy of a 5-mile -per-hour barrier collision, you must add both hardware and structure to the vehicle. This adds weight, and increased weight reduces miles per gallon."

Jan 1, 1983

By R. W. Thompkins

"PREFACEThis paper will be published in three parts. Part 1, in this issue, will cover the occurrence of uranium, radiation from uranium ores, the uranium series, radioactive theory, radioactive equilibrium and application to the radon series, the working level, the theory of emanation and diffusion, transport by thermal diffusion of radon emanating from porous rocks, and definitions.Part 2, to appear in the October issue, will deal with radiation theory applied to uranium ores, other radon migration factors , fact ors affecting the radon gas release rate, measurement of radon gas emanation rates, the tunnel concept, variation of emanation rate with grade, and estimating radioactivity from grade analysis.The series will conclude with Part 3, in the November issue, which will discuss the techniques for controlling radiation and give some example calculations.1.0. Occurrence of Uranium1.0.1. Uranium is widely distributed in nature. Sedimentary rocks contain less than igneous or metamorphic rock s and as the outer 10 miles of the earth's crust is composed of 95 per cent igneous and 5 per cent sedimentary rock, it has been estimated that about 1.3 x 1014 tons of uranium exist in the earth's crust.1.0.2. It is not surprising, therefore, that radiation has existed naturally in the ear h ever since the beginning of time. It is found in such places as:(1) non-uranium mines;(2) houses not close to or connected to uranium mines;(3) ground-water tables supplying drinking water to large populations.1.0.3. All mines do not necessarily have abnormal radiation in them, but it is possible for many mines to have abnormal levels of radiation. Therefore, all underground mining operations should be tested for radiation."

Jan 1, 1982

By X. Grant Chen, A. R. Farkoosh, M. Pekguleryuz

Nano-scale Al-(Fe,Mo)-Si dispersoids form during solution treatment in grain interiors (intradendritic regions) of cast Al7Si0.5Cu0.3Mg alloyed with 0.3Mo (wt.%). Unlike the Q-Al5Cu2Mg8Si6 and ?-Al2Cu age-hardening precipitates which coarsen resulting in loss of strength in Al-Si-Cu-Mg alloys, these Mo-containing dispersoids are thermally stable and retain their strengthening effect at elevated temperatures. Consequently, the age-hardened Al7Si0.5Cu0.3Mg0.3Mo (wt.%) exhibits high strength and creep resistance at 300 °C.

Jan 1, 2014

By R. G. Eggert

"A critical element, as the term has come to be used, provides essential properties to a modern engineered material and is subject to supply risk. The rare-earth elements became perhaps the most prominent of the critical elements in recent years because of their important uses in permanent magnets, advanced lighting, and military materials; the geographic concentration of production in China; and the dramatic run-up in prices in 2010-2011 followed by price collapse between 2011 and 2016. Yet criticality extends beyond the rare earths. What is critical depends on your perspective – who and where you are, and when you ask. This paper reviews the many perspectives on, or faces of, critical elements. It compares and contrasts perspectives of industry (General Electric), national or regional manufacturing sectors (Japan, European Union), emerging energy technologies (as seen by U.S. Department of Energy and, separately, Joint Research Centre of the European Commission) and the world as a whole (as evaluated by academics). This comparison reveals a diversity of not only perspectives but also methodologies and time frames of concern.INTRODUCTIONRare-earth elements appeared prominently in the news in 2010 and 2011 because of the dramatic increase in their prices; their important uses in permanent magnets, advanced lighting, and military materials combined with the geographic concentration of production in China, which reduced export quotas significantly. Rare earths became the most prominent of what have become known as critical elements or materials – that is, those that provide essential properties to modern engineered materials and yet are subject to supply risks.Yet criticality, the state of being both essential and subject to supply risks, extends beyond rare earths. What is critical depends on your perspective. This paper begins by reviewing a little history and presenting a general conceptual framework from which to think about critical materials. It then reviews the many perspectives on, or faces of, critical elements – corporate, national, and global, as well several that focus on emerging energy technologies. The paper concludes with thoughts on what to do to mitigate the potentially negative effects of the supply risks associated with criticality."

Jan 1, 2016

By R. J. Mitchell

"Centrifuge modelling of earth structures is a well-proven technique for evaluating the performance of prototype structures using physical models. The applications of this technique have increased dramatically during the last decade such that even the modelling of dynamic responses in structures has been accomplished.This paper presents the first model test results used to design a mine backfill. The models were tested using a 3 m radius 30 g-tonne geotechnical centrifuge which was constructed at Queen's University specifically for model studies on mine backfill stability and subsidence. The models represent the first production blast-hole stope to be mined at Westmin Resources Ltd. 's H. ~ Mine on Vancouver Island. This paper includes photographs of:model failures in the centrifuge and correlations of model test results with analyses based on unconfined and triaxial test data.IntroductionDuring the feasibility study and development stages for the H.W. Mine, Westmin Resources Ltd. conducted a comprehensive rock mechanics and backfill engineering program. The results of these studies indicated the need for assurance of backfill stability during pillar recovery on the initial blast-hole mining block. The cemented tailings backfill had to be free standing for heights up to 25 m and the potential for surcharge loading from a weak hanging wall zone, the potential for fill block sliding down-dip and the potential for seismic loading had to be considered in the design of the fill strength. The basic questions to be answered were: what cement content is required and will the resulting backfill costs be economic relative to the proposed mining method and sequence? Figure I shows a typical cross-section through the first mining block . The up-dip stope is to be mined first and backfilled with cemented tailings . The down-dip stope would then be mined and filled. Depending on ground conditions encountered, the complete intervening pillar could be recovered and the void backfilled with uncemented tailings or it could be recovered in small sections by exposing limited back and wall areas, backfilling with waste rock and I or cemented tailings . This latter method is commonly referred to as the Avoca method"

Jan 1, 1987

By Douglas W. Reeve, Hoc Nghia Tran, David Barham

"In kraft pulp mills, the spent pulping liquor is concentrated and used as fuel in the recovery boiler. Extensive deposits are formed in the upper section of the boiler due to the very high ash content of the fuel and the volatite nature of the ash. Deposits are composed of Na2S04, Na2C03 NaCI, some potassium salts and reduced sulphur compounds. Chloride and potassium salts are enriched in the deposits compared to the smelt due to their greater volatility.Severe corrosion of the superheater tubes in a recovery boiler has been traced to three factors: a non-uniform temperature profile in the flue gas, relatively high operating steam temperatures and high chIoride and potassium concentrations in the fireside deposits.The role of chIoride and potassium in superheater corrosion has been explained by increased Iiquid phase in deposits. Together with corrosion studies, this information has shown that kraft recovery boiler superheater corrosion due to the chloride and potassium enriched deposits can be avoided by proper boiler operation and by judicious superheater and furnace design.IntroductionThis investigation of recovery boiler superheater corrosion was initiated by the discovery of severe corrosion of the final stage superheater in a Canadian closed cycle kraft pulp mill(1,2). Metal wastage leading to tube failure was believed to be due to three major causes : the relatively high operating steam temperatures, the uneven distribution of flue gas temperature across the boiler which created a "" hot spot"" and the high chloride and potassium concentrations in the superheater fire side deposit. The mill responded to the problem by i) lowering the superheater steam temperature from 475°C to 380°C, ii) minimizing the chloride content in the spent pulping liquor, by controlling the NaCI input with recovered bleach plant effluent, and iii) changing metallurgy of a portion of the bottom section of the final stage superheater platens from ferritic steel T-22 (2.25% Cr, 1% Mo) to austenitic steel Incoloy 800H (21% Cr, 32% Ni, 46% Fe, 1.5% Mn, 1% Si, 0.6% Al) (Fig. 1). Details of the superheater corrosion experienced in the closed cycle mil! have been reported in previous papers(l ·2,) ."

Jan 1, 1984

By J. W. Hendry

"This paper will discuss the application of tools and the evolution of computer-assisted procedures in the production planning process at Quintett e Coal Limited (QCL). In 1986, QCL produced 5.3 Mt of clean coal from their surface mining operation located in north eastern British Columbia. The structural complexity of the sedimentary deposit and high rate of mining necessitate the consideration of large amounts of geological information which continually updates the interpretation. There are multiple unit operations required during the process of mining through a given multi-seam sequence, which results in many interdependent faces, and multiple iterations of scheduling sequences in order to satisfy a given set of objectives. In order to facilitate these activities in a timely fashion, it was recognized that a computer systems' capability needed to be developed which could increase the efficiency of information input, manipulation and output. IntroductionQuintette Coal Limited (QCL) has been operating a large metallurgical open pit coal mine in northeastern British Columbia, since 1982. The mine produced 5.3 Mt of clean coal in 1986 for export to Japan. Throughout the start-up period and the subsequent build -up of production levels, it became evident that the primary producing area was comprised of extremely complex faulted structures. This has resulted in development and modification of specialized mining methods employed to effectively recover the resource. Similarly, the planning and engineering techniques employed have been evolved over the same period of time. The implementation of computerized methods has been one of the major developments in this process, including geology interpretation, modelling, reserve definition, quantification, production planning and scheduling, and graphical plan presentation. These capabilities have been employed, in various forms, for project scale feasibility work and long range planning for some time, however, the use of computer tools for short-term, detailed production planning of a complex mining environment presents a different set of problems. It is hoped that a presentation of the current state of evolution and future plan s for development will be of interest to organizations considering implementation of a similar system."

Jan 1, 1988

By J. Lu, M. Mohammadi, C. Pelletier, B. Wassink

Chemical reduction of selenate by chromous ions is proposed as a novel method to remove selenate from sulfate-bearing solutions Chromous ions were generated by electrochemical reduction of chromic ions using an electrochemical cell. The investigation was conducted in sulfate medium and under various concentrations of chromous ions (0.0062 to 0.05M), pH 1 to 2.2 and temperature 10 to 60°C. Selenate ions were rapidly reduced by chromous ions to hydrogen selenide. The overall reaction at a chromous/selenate molar ratio of 8 or higher can be expressed by the following reaction. At an initial chromous/selenate molar ratio below 8, the products are hydrogen selenide and elemental selenium. At a lower chromous/selenate molar ratio and pH, more elemental selenium and less hydrogen selenide are produced. The reduction kinetics is controlled by both chromous ion and hydrogen ions concentrations. The reaction rate is first order with respect to selenate, hydrogen ion and chromous ion concentrations. It was found that the selenate reduction rate with chromous is independent of the concentration of sulfate present in the solution. The general rate equation was proposed and the rate constant was calculated as k= 0.38 M-2s-1. An activation energy of 58.7 kJ/mol was obtained in the temperature range from 10 to 50°C. Nearly 100% of selenate can be reduced to H2Se from solution containing 17 ppm selenate in less than 30 minutes at pH 2.2 and 60°C. Various strategies have been tested to remove the produced H2Se from solution. INTRODUCTION Selenium in nature is mostly associated with metal sulfide minerals such as copper, iron, zinc, and lead sulfides (Zingaro & Cooper, 1974). The extraction of metals from ores has the potential for selenium contamination of ground and surface water which can pose an environmental and health concern. Therefore, selenium contamination in the receiving environment is a key issue for many industries (specifically copper industry) and the treatment of wastewater contaminated with selenium is a growing challenge. The effective removal of selenium from contaminated water is very important to support sustainability in the copper industry and the other industries with selenium pollution issues.

Jan 1, 2019

By J. Peck, M. J. Scobie, M. D. Pollitt

"IntroductionOne aspect of current research in the Canadian Centre for Automation and Robotics in Mining (CCARM) involves the automatic identification of different rock types based on particular drill performance parameter responses. In this paper, the four drill performance parameters of torque, pulldown pressure, rotary speed and penetration rate, were measured from an instrumented rotary blasthole drill during field investigations undertaken at the Fording River Mine, Elkford, British Columbia. The variations in these parameters were subsequently correlated with the corresponding rock types using the results from gamma, neutron and core logs in the same or adjacent boreholes. Work to date has sought to understand the relationships between drilling performance parameter variation and rock properties. Using the results of these studies, the present research is aimed at developing techniques whereby classical statistical pattern recognition methods are applied to drill data to permit the discrimination of different rock units. A monitoring system incorporating such a capability would greatly enhance the quality and amount of geological information on a per borehole basis while drilling. This data in tum could be used economically and directly towards explosive loading, geological exploration and reserve estimation. Background and PhilosophyThis work is an extension of equipment monitoring studies at the Fording River Mine. At this site over a two-year period, 5180 m of data was acquired on an instrumented Bucyrus-Erie 60R drill during routine production blasthole drilling. Throughout these studies, a 311mm diameter S8M Security tungsten-carbide tricone bit was used. The mine, located in southeast British Columbia, is a large-scale, open pit coal operation. The means of excavation revolves around a drill-blast-muck cycle and employs a standard shovel-truck system of transport. Four main rock types are present: sandstone, siltstone, mudstone and coal, with average compressive strengths ranging from 10 MPa to 150MPa respectively (peck 1989). However, based on the field studies, very few differences in terms of strength and compositional properties were seen between the sandstones and siltstones at the site. Therefore, they are referred to as sandstone/siltstone in all further discussions."

Jan 1, 1991

By Song (Bruce) Li

This paper presents a three-tier web-based GIS application that uses Java Server Page (JSP), Java Servlet and relational database to manage performance monitoring and reporting in the oil sands mining industry. It is a real-time Earth Structure Performance Monitoring System (ESPMS), which allows the user to record and store instrumentation monitoring readings as well as technical observations and instrumentation installation documentations into a complete relational database. The ESPMS introduces the advantages of precise field record keeping, due diligence, security, consistency and completeness while at the same time simplifying the task of reporting. ESPMS combines web-based Geographic Information System (GIS) mapping and data management to facilitate the collection, organization, retrieval, reporting and communication of the vast amounts of monitoring data related to mining and tailings engineering associated with site investigation and construction information. ESPMS utilizes web-based GIS technology to incorporate referenced aerial photographs, Energy, Mines and Resources (EMR) maps or AutoCAD drawings as a base map for the monitoring site. It dynamically creates and administers all instrumentation monitoring locations and reading frequencies. It enables the user to collect and manage the data associated with an unlimited number of reading events. It provides the designer with real-time monitoring data (what, why, when, how), thereby allowing them to make early adjustments to design protocols or procedures, or to take remedial action(s) regarding the subject earth structure under construction or after completion. It provides more cost-effective reporting and data sharing through the Internet. It improves security on data entry and eliminates unauthorized data changes. It allows better integration of graphics and illustrations with numerical data files. It is capable of managing the continually expanding workload resulting from new and larger structures in the oil sands or other mineral mining industries. The ESPMS facilitates easier data gathering for preparation of as-built and after-built or regulatory reports, etc. It enables quick location of the interested instruments and summarization of the performance of the instruments. It enables one to visualize performance data and QA/QC construction test results spatially on any given cross-section. Data can be exported to MS Excel for detailed analysis and to evaluate the stability of the earth structures.

May 1, 2004

By B. J. Fryer, R. P. Taylor

"As a monitor of the processes involved in the formation of granitoid mineral deposits the coherent group behaviour of the rare earth elements (REE) actively reflects changing fluid characteristics. For example, in the porphyry environment, magmatic-hydrothermal fluids produce potassic alteration with strong enrichment in the light rare earth element s (LREE), reflecting their high pH, low fluid/rock ratios, and the dominant role of CI- complexing in metal (i.e. Cu, Au) transport. With increasing fluid/rock ratios and decreasing pH accompanying the progressive involvement of meteoric fluids (and the production of propylitic, argillic, and phyllic alteration) anionic species such as F - and CO, 2- become important in metal (e.g. Mo, W,) transport through complexing, and their activity in the hydro thermal fluids is illustrated by mobilization of the heavy rare earth elements (HREE).The relative involvement of CI- versus F - versus CO32- in metal transport in other granite-related systems can also be monitored through REE behaviour. Hence granitoid tin-tungsten mineralization and associated greisenization typically exhibit heavy rare earth enrichment and evidence the importance of F' and CO32- in metal transport. Similarly, heavy rare earth element enrichment in hydrothermal uranium deposits can be related to the transport of uranium as carbonate complexes. REE are widely accepted as powerful tools in the study of rock petrogenesis, but their use has been neglected in the investigation of mineral deposits. The recognition of the systematic variation of REE distributions in granitoid mineral deposits suggests that the application of REE geo chemistry, particularly when integrated with fluid inclusion and isotope studies, can provide (1) an effective method for identifying the physicochemical controls of metal transport and (2) a useful criterion for elucidating metal distribution."

Jan 1, 1983