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By Abani R. Samal

The Fe assay values from the diamond drill-holes within a magnetite deposit of magmatic origin are utilized in this study. Only assay data from the unoxidized magnetite mineralization was utilized. The data from the overlying hematite mineralization zone was not used. A threedimensional block model estimated using ordinary kriging (OK) is used for analysis purposes. To estimate the non-linear standard deviations (s) and the confidence intervals (CI) of block estimates a discrete Gaussian variogram model is used in this project. The change-of support coefficient (rv) and the block-support correction are used in the ?block-anamorphosis?. A new calculated value of rv is 0.7283, implies that its influence in the block-anamorphosis is not significant. The CIs are calculated from the block-gaussian variables; then back transformed to the raw values. At 95% probability, the CI for the kriged block estimates of Fe values are calculated using Gaussian kriged estimates of the Fe and the corresponding standard deviations (Gaussian). The results indicate that the block estimates with a high influence from relatively small amount of samples can be identified as high-risk estimates.

Oct 1, 2009

"The Dome Mine, located in South Porcupine Ont. has been in operation since 1910 and is owned and operated by Placer Dome Inc. The current milling facilities were constructed in two phases with the first being commissioned in 1982. It consists of a grinding, gravity separation, thickening, and leaching circuits. The second phase was commissioned in 1988 with the addition of the CIP, stripping, electrowinning, and carbon regeneration circuits.It is now common practice in the gold processing community to add liquid oxygen to leach circuits to increase both recovery and kinetics. Along with these benefits the metallurgical group at the Dome realized the potential to replace compressed air with liquid oxygen as a source of oxygen for the dissolution of gold. A plant trial of liquid oxygen was undertaken during the fall of 1991. The results of this first test were favourable enough to warrant further investigation, and a second plant trial was conducted in December 1991.The data generated as a result of each trial revealed that oxygen could be economically substituted for compressed air as a source of dissolved 02. The energy savings in required horsepower enabled a rapid payback period. Thus the project was approved in the spring of 1992 and l should be operational during the final quarter of 1992. INTRODUCTIONIn a continuing effort to reduce operating costs and improve recovery at the Dome mill it was decided to investigate the feasibility of adding liquid oxygen (02) to the leach circuit. It is now common practice in the gold processing community to add 02 to the leaching process to increase both kinetics and recovery. It was anticipated that an increase in kinetics would allow us to eliminate one or more leach tanks while maintaining acceptable recoveries. The metallurgical group felt that along with these benefits, the potential was also there to reduce power consumption through the reduction in the processing of compressed air which is quite costly (12 cents/1000 cubic feet per minute in 1991)."

Jan 1, 1993

By Z. Mubarok

An overview of the problems encountered the electrorefining of copper anodes containing high levels of nickel and antimony is presented. Our investigations have been focusing on the passivation behaviour of the anodes with high contents of Ni, Sb, Sn, and Pb, the formations of kupferglimmer and floating slimes. The results of linear voltammetry, chronopotentiometry and electrolysis test revealed a noticeable lower resistance of the anodes to passivation in comparison to those with lower contents of Ni, Sb, Sn, and Pb. Anode containing kupferglimmer exhibited oxygen gas evolution during the passivation state. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) indicated that tin can replace and/or join antimony in the kupferglimmer structure. Under specified experimental conditions, floating slimes precipitations took place with high Ni, Sb, Sn, and Pb anodes prior to the end of one anode period.

Jan 1, 2007

By John Blackshaw

NEW sources of supply of tungsten concentrates became necessary when the flow from the Far East was blocked in 1942. In Canada, one source has been noted in the workings of the Hollinger mine at Timmins, Ontario. For many years, a small amount of scheelite had been removed with the gold ore, and an appreciable tonnage of scheelite still remained in the mine. At the request of the Dominion Government, a plant was built to recover this scheelite in the form of a concentrate that could be used by the alloy-steel industry without further preparation. The plant began operating early in March, 1942, and a small tonnage of ore, carrying scheelite and gold values, has been treated daily since then. The possibility of recovering the scheelite had been considered on several previous occasions. Each time the proposal had been given up because the total profits from the enterprise were estimated to be insufficient to repay the capital cost of building the recovery plant. At the time the plant was built, additional information had been gathered about the tonnage and grade of the scheelite ore in the mine, and several thousand tons of ore grading higher than 0. 25 per cent WO3 (tungstic trioxide) were known to be available.

Jan 1, 1943

By Shinji Muraishi, Shinji Kumai, Yasutaka Kedo, Takashi Kambe

"Magnetic pulse forming (MPF) is one of the extreme high-speed forming processes. A metal sheet which is accelerated by electromagnetic force is collided onto a mold and fine and sharp details of the product can be obtained. The deformation mechanism of the MPFed metal cannot be understood only by the microstructure observation of the deformed metal. The deformation behavior of the metal should be investigated also by considering the local microstructure change with strain, strain rate and temperature change during deformation. Numerical analysis is an effective method to achieve this requirement. In this study, pure Al and Cu sheets were deformed by MPF. Impact velocity of the metal sheet was calculated by using ANSYS Emag-Mechanical. Based on the obtained impact velocity, the deformation behavior of the metal sheet was reproduced, and local strain, strain rate, and temperature were analyzed by using ANSYS AUTODYN. The relationship between the local microstructure change of Al and Cu sheets and the deformation parameters was examined.INTRODUCTIONMagnetic pulse forming (MPF) is one of the high-speed forming processes using electromagnetic force. Fine and sharp details of the product can be obtained, and springback after deformation is extremely reduced in comparison to the conventional forming processes(Psyk, Risch, Kinsey, Tekkaya, & Kleiner, 2011). Figure 1 shows a schematic diagram of MPF. A metal sheet is placed over the coil in the discharge circuit. The discharge current runs through the coil, and magnetic fieldis producedaround the coil. An eddy current is inducedin the metal sheet. Interaction between magnetic field and eddy current creates electromagnetic force. The metal sheet accelerated by electromagnetic forcecollides ontothe mold. Forming is completed in a few tens of micro-seconds.MPF is suitable for metals with a high electrical conductivity like Al and Cu.The MPFed metal may have characteristic microstructure because of high strain rate deformation."

Jan 1, 2018

By W. M. Williams

"Although manganese is a metal virtually unknown to the layman, it is hardly necessary to point out to the engineer the importance of manganese in modern metallurgy, an importance intimately linked with iron (and steel), the basic materials of engineering construction for hundreds of years and certain to remain so for long into the future. World steel production will approach and perhaps reach 1 billion tons/year in the 1980s; with a manganese content between 0.5% and 1 % in ordinary steels, and more in specialty steels, manganese use worldwide will soon approach 15 million tons annually. Manganese was discovered and isolated in Sweden in 1774 by Karl Wilhelm Scheele (who also discovered molybdenum), but the element was only of scientific interest for several decades. By the early part of the nineteenth century, however, manganese oxide had become commercially available and was in use for colouring glass and for the production of chlorine. Commercial application in metallurgy appears to have been limited to the manufacture of crucible (or ""cast"") steel, a highquality product made by carburizing wrought iron, and melting it in small batches to make ingots which could be rolled and used for special applications, e.g. for the manufacture of fine tools or for ""steeling"" the cutting edges of implements such as wrought iron axes and chisels.* However, it was not until Bessemer's epoch-making invention of cheap steel in 1856, and the dramatic expansion of the steel industry thereafter, that manganese assumed the importance that it holds in modern steelmaking."

Jan 1, 1999

By Ron Jessulat

"IntroductionBrunswick Mining and Smelting Corp. Ltd. is a IO 500 tid base metal producer. Development is carried out by Jarvis Clark MJM-21 3-boom development jumbos, using Tamrock E400, 410 and 550 pneumatic drills. Typical drift size is 13 ft by 18 ft with a 12-ft advance per round. Blast holes are 1 ½ in. in diameter while reamed holes are 3 in. in diameter. AN/FO is the principal blasting agent, being loaded by C-I-L model60R intermediate loader. The detonators are NONELS and DETINELS. Sulphide dust explosions occur during blasting when dusts from certain minerals such as pyrite and pyrrhotite are ignited by name from the detonating shots. The result is a secondary unwanted explosion with a characteristic shock wave and name front that are very destructive to mine services such as ventilation ducting, electrical cable, and ventilation control doors.A typical reaction in the Brunswick orebody occurs according to the chemical formula:4FeS 2 + IIOs-2Fe2O3 + 8SO2 + 3458--(Enright , 1988)The hematite (FeO3) is deposited as a red dust in the blast area while the toxic sulphur dioxide gas (S00 contaminates the underground workings . The presence of S02 gas disrupts production until it is purged from the area by the mine ventilation system or dissipates slowly in those areas where the vent ducting has been melted by the name front or torn down by the shock wave.Sulphide dust explosions exact a high economic toll. Direct costs in damaged materials and wages are probably exceeded by the value of lost production and disruption to the mining cycle. In addition, the health and safety concerns associated with sulphide dust explosions cannot be ignored."

Jan 1, 1993

By Sergio Fuentes

During the past fifteen years, mines utilizing the block caving method have improved performance and systematically reduced total mining costs. This paper describes improvements in mine design, mine planning and mine management, including methods enabling the Chilean and International mining industry to ensure cost savings and productivity growth while using the block caving method. These improvements have encouraged the re-evaluation of underground operations at operating and closed open pits, and challenge surface mining applications as the only low cost mining method. This paper describes a strategy to estimate the optimum open pit to underground transition time during the life of a mine.

May 1, 2003

By Bob Rappolt

Discussion Points Part 1: Global Mining Industry/Related Issues ? Historical Metal Price Trends. ? Historical LME Metal Stockpiles. ? China?s Demand for Metal. ? World Population Growth, Demands and Development. Discussion Points (cont?d) Part 2: Canadian Mining Industry ? Where are we? And where are we going? ? What progress have we made in the past 20 years regarding: ? Safety -Employee Levels ? Labour -Relative Compensation ? Productivity - Technological Advance ? Where do we stand regarding mineral production? ? What does the future hold for us?

Apr 1, 2005

By Caitlyn J. McKinley, Ahmad Ghahreman, Maziar E. Sauber

Ever-growing global needs for critical metals, such as rare earth elements (REE), and base metals, such as copper and nickel, and their environmental impact motivated the pursuit of sustainable flowsheets. Regeneration of hydrochloric acid in chloride-based leaching flowsheets as a critical unit operation is an example of such endeavours. This study presents an efficient hydrochloric acid regeneration method from a magnesium chloride solution waste by addition of sulphuric acid in relatively low temperatures. The effects of temperature, initial magnesium chloride concentration, amount of sulphuric acid added, and airflow are examined. Experimental work are focused on temperatures between 80 and 95°C, initial magnesium chloride concentrations of 2 to 5 M, 100% to 220% stoichiometric sulphuric acid additions, and airflows between 200 to 600 mL/min. The developed technology recovers hydrochloric acid at a high rate and concentration with a relatively small environmental footprint. INTRODUCTION The mining and metals sector is under increasing environmental and economic pressure to make more efficient use of chemical reagents and energy in the production process. This affects several areas of process and flowsheet design such as the selection of the most appropriate unit operations and the overall design of the process steps paying heed to sustainability. Owing to the inherent inefficiencies of physical and chemical processes used in the mining industry, there will be materials and streams generated that are not a desirable part of the envisaged flowsheet. Thus, methods are implemented to recover and recycle such effluents. If the recovery and recycling are not economical, then procedures are followed to neutralize and dispose these effluents. In many cases, these effluents are potential contaminants or hazardous materials, and their disposal should be looked at in a much larger context. The safe management of the contaminants and hazardous effluents is a daunting problem in the mining industry and is fraught with technological, economic, social, and political challenges.

Jan 1, 2019

By C. -S. Xie, J. -H. Kong

The microstructure and mechanical properties of X80 hot-rolled thick steel strips with a thickness of 17.5mm produced in Wuhan Iron & Steel Company (WISCO) are introduced in the paper. The steel strips as fabricated through proper thermomechanical processing (TMP)/ on-line accelerated cooling (OLAC) processing have shown high strength and toughness, low brittle transition temperature, good weldability, and high Shear Area (SA) percentage in Drop Weight Tear Test (DWTT). The microstructure of the steel strips is characterized with mainly acicular ferrite, and fine dispersed Martensitc-Austenite (M-A) phases. It is determined that the mechanical properties are improved due to the presence of the fine M-A phases and precipitates, which could be formed by reducing the finish rolling and coiling temperatures.

Jan 1, 2005

By Hamidreza Soltanzadeh

The injection of CO2 into a reservoir or aquifer can potentially result in deformation, induced fracturing and fault reactivation in the injection zone and/or the rocks that surround it. This paper reviews the data collection and geomechanical analyses performed to assess these potential hazards for the Heartland Area Redwater Project (HARP), in which CO2 sequestration is being considered in a carbonate (Leduc Formation) reef. A three-dimensional mechanical earth model (3D MEM) was developed using available geophysical log data from several wells. The geomechanical response to CO2 injection was studied using a finite element numerical model based on the 3D MEM and pore pressure distributions predicted using a reservoir simulator. The modeling results suggest that the potential for induced fracturing and fault reactivation is low and the maximum predicted ground surface heave is less than 2 cm. Sensitivity analyses conducted with a 2D geomechanical model that was extracted from the 3D model confirm that this conclusion holds true even when a reasonable measure of uncertainty in rock mechanical properties, ambient pore pressures and horizontal stress magnitudes is accounted for.

Jun 1, 2012

By R. H. Keyes Duval

"The one point left off the table was pumping costs, i.e. the cost of pumping to the cyclones.At East Malartic 5 x 5 S R L pumps that had been used to pump the classifier overflow were used to pump the rod and ball mill discharges to the cyclones. Maintenance costs on the pumps rose from $105 in 6 months to $1000 per month. The pumps had to be operated at 1150 rpm and impellers lasted only 5 to 6 days. These pumps were replaced by 6 x 6 S R. L. pumps operating at 825 rpm, but at this speed the coarser sands settled and plugged the pipe lines and the speed was increased to 925 rpm. The maintenance cost is now $100 per m::rnth which is 0 003 cents per ton milled. The impellers now last 1 month and the casing linings 6 months.Density meters are often used on cyclone overflows and sometimes on the cyclone feed. Haliburton weighted tube density meters are used in some plants. They are cheaper than the radioactive density controller, $2500 as compared to $ 6000The angle of the discharge spray from the apex can be used to judge the quality of perform1nce of a cyclone.For ordinary metallurgical applications the inside slope of the cyclone is not too important but for fine separation steeper slopes are used.The cyclone is a versatile tool and will handle considerable variations in feed tonnage - probably up to 15%. Above this variation the number of cyclones used has to be increased or decreased or the tonnage fed to them has to be adjusted"

Jan 1, 1965

By Sarah Bélair, Denis Beltrami, Deka Moussa Ragueh, Valérie Weigel

"Scandium is a highly valuable element belonging to the rare earth elements (REE) but it has different chemical and physical properties from those of lanthanides. This metal is generally used in aluminum-scandium alloys and in fuel cells but the development of its market is slowed down by its high price (more than 1000 US$/kg for a 99.0% grade product). Indeed, the low scandium content in the continental crust (an average of 22 ppm) and the difficulties to extract it selectively from solutions containing high impurity concentrations increase the cost of the recovery processes. Nowadays, scandium is primarily recovered as a byproduct.ERAMET is developing a hydrometallurgical process in Gabon (Mabounié) in which the scandium content in the deposit reaches 10 to 100 ppm. The Maboumine project consists in the extraction and purification of uranium, niobium, tantalum and REE from Mabounié ore. In the frame of this hydrometallurgical project, ERAMET had also studied the feasibility to recover scandium as a byproduct. During the ore leaching, uranium and rare earth elements including scandium are solubilized into the pregnant leach solution (PLS). Among the various methods investigated to recover scandium from the PLS, liquid-liquid extraction using Primene JM-T as extractant was chosen and tested first at laboratory scale and then at pilot scale. Selective stripping of the loaded organic was carried out by using phosphoric acid solution, allowing the selective recovery of scandium from thorium and zirconium partially extracted from the PLS by Primene JM-T under the process conditions."

Jan 1, 2016

By M. Jahazi, J. Gholipour

Design and manufacturing of parts using hydroforming process require knowledge about material behaviour and tribological effects during hydroforming. Lubrication is one of the key issues in successfully hydroform the tubes. A Ni-based super alloy tube with 50.8 mm (2 inches) outer diameter and 0.9 mm (0.035 inches) thickness is considered for this research to study the effect of lubricants on the formability of the tubes. Hydroforming of a hollow compressor blade is considered for this project. A combination of press forming and hydroforming is employed to produce the part. LS-DYNA, an explicit dynamic finite element code, is used to model the experiments. Different lubricants are modeled using different coefficient of friction in the model. Predicted results for strain distribution at a critical section of the tube are extracted for each case to evaluate the effect of different lubricants on the process.

Jan 1, 2006

By C. Barnett

"A description of the Geco orebody has been given by W .L. Brown and R.C.E. Bray (1). The mill flowsheet and equipment were described by M.J.S. Bennett, D. Wild and C. Lawton (2). Mill capacity is now 4, 150 tons per operating day of copper, silver, zinc and lead ore. A recent flowsheet has been published in the - Canadian Mining Manual (1966).Soon after the start of production in September 1957, it became apparent that large tonnages of sand would be required by the mine for backfill pruposes. Initial experimental work on the preparation of sand fill from the flotation tailings was begun in late 19 59. Cyclones of local manufacture, in a variety of sizes, were tested quite successfully. There were, however, several obvious advantages with some of the custom-built cyclones and a recommendation was obtained from the Techniquip Company. A single Krebs D-10-B cyclone was tested experimentally in 1960.INITIAL TESTWORKExperimental results showed that with our relatively coarse grind (in the order of 53 % minus 200 mesh) 75 - 80% of the flotation tailings could be recovered as backfill sand with one stage of treatment. Percolation rates of four inches per hour were obtained with cyclone inlet pressures in the range of 20 - 25 psi and feed densities of 20 - 23% solids."

Jan 1, 1968

By Daniel Hodouin, Mélanie Proulx, Claude Bazin

"Collector and frother are commonly used to induce the floatability of valuable minerals in flotation plants. These reagents are usually distributed down a flotation bank or sometimes added in a single location at the top of the bank. A review of the literature and some experimental results obtained from laboratory and full scale trials indicate that the way flotation reagents are distributed down a flotation bank may influence the flotation response of coarse particles. The paper summarizes these observations which show that the distribution of reagents is a potential tuning variable for process optimization.IntroductionFlotation is in many cases the only way to concentrate sulphide and some oxide minerals. Flotation is a concentration process that uses particle surface composition to induce the selectivity by mean of hydrophobic reagents. The influence of particle size on flotation was firstly analyzed in the 50's1·2 and intensively investigated in the 70's, early 80's and 90's3-18. Most of the observed results show the existence of an optimum flotation size range9 whose recovery is not significantly influenced by a reduction of collector dosage""18. This result brought the idea of using a small portion of the total collector dosage at the top of a rougher bank and to distribute the remaining through the end of the bank to ensure sufficient collection of the coarse particles that need more hydrophobic coverage to attach to air bubbles and be lifted to the surface.This paper discusses the idea of using the distribution of reagents down a flotation bank to tune the operation of the process. Unlike the literature on the effect of reagents (collectors, frother...) dosage that is dense, little attention has been put on the distribution of reagents in a flotation bank. Although research on this subject has not been pushed very far, some operators have recognized the potential of a strategic addition of reagents down a flotation bank19. Except for a few exceptions, the proportions of the reagents to be distributed down a flotation bank are decided according to operator's experience instead of process analysis in relationships with particle size. This paper recalls observations made by different researchers that lead to the idea of using the distribution of reagents as a tuning variable for the flotation process. The paper does not present a detailed analysis or optimization scheme for tuning the distribution of reagents, but analyzes some plant and laboratory results with a view toward the development of a testing methodology and ultimately a validation or rejection of the idea."

Jan 1, 1998

By B. Skrotzki, E. Augenstein, C. Rockenhäuser

"The aluminium alloy 2618A is an Al-Cu-Mg alloy with additions of Fe and Ni, which is designed for long-term operation at elevated temperature in transportation and aerospace industries. The alloy degrades due to coarsening and dissolution of GPB zones and coarsening of S-Phase precipitates (Al2CuMg). This work investigates the overageing process at the application relevant temperatures of 190 °C for durations ranging up to 25,000 h. The nm-sized precipitates were selectively imaged along the <001>a direction of the Al matrix using dark-field transmission electron microscopy. The resulting images were then evaluated and allow the statistically relevant determination of radii distributions and the average radius of the precipitates dependent on temperature and heat treatment duration. Ostwald ripening of the S-phase does not describe the ageing process adequately. Instead, the evolution of GPB zones during the initial ageing regime needs to be considered in addition to the coarsening process of the S-phase. DSC measurements were performed to determine the presence of GPB zones in different ageing states. This will allow a quantitative description of the ageing process and a comparison to samples aged under external load.INTRODUCTION Alloy 2618A is an Al-Cu-Mg alloy, which is part of the 2XXX series of aluminium alloys. It is used in aerospace and transportation industry due to its desirable material properties for long term operation at elevated temperatures (Polmear, 2006). Fe and Ni are added to form intermetallic compounds, which retain microstructural stability at elevated temperatures (Bergsma, Li, & Kassner, 1996; Elgallad, Shen, Zhang, & Chen, 2014; Oguocha, Yannacopoulos, & Jin, 1996; Wang & Yi, 2006). The size and distribution of the nm-sized S-phase formed from the supersaturated solid solution (SSSS) during heat treatments mainly controls the strength (Khan, Starink, & Yan, 2008; Liu, Zhang, Ding, Sun, & Chen, 2003; Parel, Wang, & Starink, 2010; Shih, Ho, & Huang, 1996; Wang, Starink, & Gao, 2006). The S-phase has the composition Al2CuMg and is orthorhombic under equilibrium conditions (Heying, Hoffmann, & Pottgen, 2005; Perlitz & Westgren, 1943). Early experiments proposed the following decomposition of the S-phase sequence during heat treatments (Hardy & Heal, 1954; Silcock, 1961):"

Jan 1, 2018

By Robert A. Creaser, David R. Lentz

Abstract - The Moss molybdenite deposit, which was mined during both world wars, is hosted in late Grenvillian granitic pegmatite dikes. These dikes are locally aplitic, and intrude the late tectonic Onslow syenite (probably correlative with the ~1090-1070 Ma Kensington suite), which is in turn intrusive into the 1170-1155 Ma Chevreuil intrusive suite of southwestern Quebec. A Re-Os model age of 1053 ± 4 Ma (8.3 ppm Re) was obtained for molybdenite from a pegmatitic veinlet within an aplitic phase of the dike. A much younger Re-Os date of 860.9 ± 9.2 Ma (6.9 ppm Re) obtained previously from a pyrrhotiteand pyrite-rich metasomatic vein might reflect Os diffusion during slow cooling of the Grenville province, because this age is consistent with K-Ar dates reported from the region. Alternatively, the similarity between these younger dates may be fortuitous, and may instead relate to sampling issues for molybdenite. The Mo-rich granitic dikes at the Moss deposit are similar to other Mo-rich A-type pegmatite-aplite granitic dike systems that formed immediately after the peak of the Ottawan orogeny (1070-1090 Ma), and possibly are more closely related to the Kensington suite than previously thought.

Jan 1, 2005

By Mario A. Morin

Over the years, several sources have stressed the need to better integrate the underground mine design and planning processes. The belief is that with better integration, better designs and plans will result - designs that are ?optimized?. Some researchers have focused their efforts on data integration, others have looked at closing the loop between production control & monitoring with mine planning & scheduling. In spite of all these efforts, fully integrated applications combining geological modeling, stope design and geomechanics, mine planning and scheduling, rock extraction and material handling system design, mine support systems, economic analysis with production control do not yet exist for the underground hard rock mining industry. There are several likely explanations - some economic, some technical. It is certain that the design and planning processes are interrelated and interdependent and thus are extremely complex to describe and understand. The mining engineer has an appreciation of the complexities involved - but how does he convey this knowledge to a programming team responsible for developing an integrated design & planning system. This paper will focus on software engineering methods, and other possible approaches, to describe and manage the complexities inherent in the underground mine design and planning process and the development of an integrated computerized system.

May 1, 2001