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By D. Paul Bishop, Kevin P. Plucknett, Hung-wei Liu

"Spark plasma sintering (SPS) process has been evaluated for producing the commercially pure (CP) Ti, TiAl and a TiAl-B4C composite. Comparisons were made between the materials in terms of the sintered density, resultant hardness and microstructures. In the present work, the titanium aluminide powders (Ti-48Al, producing a mixture of y-TiAl/a2-Ti3Al) were synthesised „in-house? using a simple reaction-sintering and mechanical attrition approach. This allowed various size distributions to be generated. The powders were then blended with a fine boron carbide (B4C) powder (up to 6 wt.%), and the resulting mixtures were consolidated using spark plasma sintering (SPS) under vacuum in graphite dies. An applied stress of 50 MPa was used for all SPS runs. The SPS parameters were varied in terms of the ultimate sintering temperature (up to 1300°C) and hold time (up to 10 minutes) for each material. It is demonstrated that high densities can be achieved this approach (exceeding 95% of theoretical, with optimised samples close to full density). Microstructural characterisation was conducted using optical microscopy, scanning electron microscopy, and X-ray diffraction. The B4C additions were seen to partially react with the TiAl to form reinforcements, such as TiCx and TiBx. Preliminary mechanical property assessment will also be briefly discussed.INTRODUCTION Titanium- and titanium aluminide-based alloys possess many unique properties, such as excellent corrosion resistance and high temperature strength, respectively (Cardarelli, 2001; Leyens & Peters, 2003). Compared to many other competing materials (e.g. stainless steel or Ni-based alloys), Ti- and TiAl-based alloys also have relatively low densities (~4.5 and ~3.9-4.1 g/cm3, respectively), which is critical for performance in aviation and automobile applications. However, the manufacturing cost is high, due to the expensive raw Ti material and difficulties in machining. TiAl-based alloys are particularly difficult to produce because of their limited ductility (Lütjering & Williams, 2007). To overcome those problems, powder metallurgy (PM) technologies have shown great potential as near-net shape processes for Ti- and TiAl-based alloys. The general PM process largely avoids laborious post-machining and minimises material use. In industrial production, the PM approach has been successfully utilised to manufacture aluminium- and iron-based alloys (Huo & Heath, 2008)."

Jan 1, 2017

By C. Beaudry

Outline ? General Geology of Frieda River Project Area ? Exploration History ? Geology of Porphyry Deposits ? Porphyry Resource ? Update of Nena Deposit and High-Sulfidation Mineralization ? Nena Resource

May 1, 2006

By A. Manouchehrian, M. Cai

"Rockburst, which often occurs around underground openings in highly stressed hard rocks, is a sudden and violent unstable rock failure and is associated with energy release. Rockburst is very dangerous to workers and mining equipment, and it has been a major concern for deep underground construction and mining. Before excavation, rocks are loaded under a true-triaxial condition. Upon excavation, the rocks at the excavation boundaries are loaded in the maximum principal stress direction and unloaded in the minimum principal stress direction and this provides a necessary condition for unstable rock failure to occur. Understanding rock behavior under true-triaxial unloading condition is critical for developing measures to control unstable rock failure in underground construction.In this article, an explicit FEM tool is used to simulate rock behavior under true-triaxial unloading condition, with a focus on analyzing stable and unstable failure and the released energy during failure. Firstly, a uniaxial compression test was simulated. The results indicated that the adopted numerical tool was able to simulate stable and unstable failure by varying the Loading System Stiffness (LSS). In this research, Loading System Reaction Intensity (LSRI) was proposed as an indicator to identify stable and unstable failure. Secondly, unstable rock failure under true-triaxial unloading condition was simulated. A rock specimen was loaded in three directions; the lateral pressures (s3 and s2) were kept constant and the vertical stress (s1) was increased to a pre-defined stress. The specimen was suddenly unloaded in the minimum principal stress direction (s3) and loading in the s1 direction was continued until failure occurred. Different LSS values were considered and the results showed that the LSS influenced the failure mode; a soft loading system resulted in more violent failure and released more energy than that in a stiff loading system. The influence of specimen height to width ratio on rock failure was also investigated. It was found that failure in taller specimens was more violent than that in shorter specimens. Insights gained from the simulation are useful for better understanding of the influencing factors on the released kinetic energy during unstable rock failure and to find means to control rockburst damage in engineering practice."

Jan 1, 2015

Terrane?s Canadian Assets Mt. Milligan, British Columbia Copper, gold (100%) Berg, British Columbia Copper, molybdenum (100%) Howards Pass, Yukon/NWT border Zinc (Option payments, and Royalty interest) Maze Lake, Nunavut Gold (Joint venture with Laurentian Gold Fields)

May 1, 2010

By L. Vollert

"The application of pneumatically-assisted fluidized bed flotation, specifically the ERIEZ HydroFloatTM technology, has found widespread use in non-sulphide processing (particularly phosphate, potash and coal) for the recovery of coarse particles. In gold processing, centrifugal gravity circuits and flash flotation cells are typically employed for the recovery of coarse and near-size liberated gold which tends to accumulate in recycled grinding streams due to bypass to the classifying cyclone underflow streams owing to the higher specific gravity of these gold particles. Early removal of this gold from the grinding circuits contributes toward the reduction of downstream processing losses as a result of overgrinding and particle shape deformation in the case of flotation processing, longer leach residence times in the case of extractive processing, and surface occlusions in the case of both flotation and extractive processing. Furthermore, recovery to bullion attracts higher payment terms by way of comparison to concentrate sales in the case of copper-gold concentrators. This paper assesses the application of pneumatically assisted fluidized bed flotation for the recovery of coarse liberated gold through the analysis of piloting data generated from the operation of a continuously operated 16 inch ERIEZ HydroFloatTM unit treating a sized coarse grinding circuit stream. The paper presents the stage recovery by size performance of the ERIEZ HydroFloatTM unit together with quantitative gold deportment analysis to demonstrate the efficiency with which gold was recovered during this pilot campaign and then compared to more conventional processing units – centrifugal gravity and conventional flotation.INTRODUCTION Newcrest Mining Limited (NML) has identified that an opportunity exists for improving the recovery of coarse composite particles at its current operations, both as a means for improving overall recovery and as an opportunity for early gangue rejection. As such, Newcrest Mining Limited has taken an interest in the application of pneumatically-assisted, fluidized-bed flotation i.e. ERIEZ HydroFloatTM technology. This interest dates back to 2011 with sighter testwork carried out on their Australian-held ore bodies (Kohmuench et al, 2013). Newcrest continues to assess ERIEZ HydroFloatTM potential for coarse composite recovery and, in the case of the topic of this paper, coarse gold recovery based on examples in the literature which demonstrate the efficiency of this technology in this regard (Carmona Franco et al., (2015); Miller et al., (2016); and Kohmuench et al, 2013)."

Jan 1, 2017

By Patrick J. Williams

Outline -An Australian View On: ?IOCG defining features and occurrence ?Variable exploration characteristics ?Extracting value (gold metallurgy) ?Recent exploration experience(case study)

Apr 1, 2005

By Hermann A. Derbuch

Twin Mining made a conscious decision when it changed from gold mine explorer and developer to become a diamond explorer in Canada?s Arctic. It was a decision of survival in an environment that saw junior gold companies either disappear or turn into dot com companies. Twin Mining learned fast and staked within weeks of that decision the first 50 sq. km of claims on, what became, its TORNGAT property at 59½° latitude on the east coast of the Ungava Bay in northern Quebec. This land position, 724 diamonds later (including 322 macro diamonds of gem quality, white and transparent) grew to 507 sq. km today. The 74° latitude called when Twin Mining exercised the option to acquire 3 claims owned by Helix Resources Inc. which revealed exceptional diamond potential. A gem quality 5.4 mm (0.768 carat white and transparent) diamond and the discovery of 16 pipes on 15.2 ha convinced Twin Mining?s board to sanction the deal. Both properties have outstanding features. Kimberlite Dykes and Pipes are in outcrop. The property locations have deep-sea access near existing infrastructure. Their locations are in an environment that is stable and development friendly and has a positive track record with successfully operating mines near-by.

May 1, 2001

By K. Dinh

The Ground Penetrating Radar (GPR) has been studied for a long time as a non-destructive evaluation (NDE) technology for inspection of concrete structures. Currently, the most widely used technique for interpreting GPR data of concrete bridge decks is the one that based on the amplitudes measured at various interfaces such as asphalt-concrete, top rebar, or slab bottom. The assumption behind this technique is that a sound concrete deck should have the same reflection amplitude at these interfaces while any low number would indicate some sign of deterioration. Unfortunately, this assumption is not completely valid in most cases. As a consequence, the reported test results usually do not reflect real condition of concrete bridge decks in question. The main goal of this paper is therefore twofold: (1) to discuss the limitations of the amplitude analysis method, and (2) to propose a new model that interprets GPR data of concrete bridge decks. The model methodology is based on the comparison of GPR A-scans between two inspections, using the so-called correlation analysis. The results, indicated by the correlation coefficients, are then employed to develop a contour map that estimates different levels of deterioration. The model is then implemented to a case study in order to illustrate its methodology.

Aug 1, 2013

This growing dependence of Canada upon foreign mineral commodities, just referred to, applies particularly in the direction of the United States. There is, in fact, no more significant feature of Canada's mineral trade than the manner in which it affects the Dominion's commercial standing with that country. Our heavy adverse balance of trade with the United States is perhaps not a matter of such wide concern or frequent comment as was the case two or three years ago. It is, of course, a well-known fact that the Dominion each year buys from the States a volume of goods to a value enormously in excess of our sales to that country. And it has come to be accepted as a ?normal, though not altogether satisfactory, feature of our international commerce that a huge portion of the bill incurred by our American purchases must be met, not by our American sales, but by the proceeds of our sales to other countries, not-ably Great Britain. It is a three-cornered situation in which our trading deficit with the United States is covered largely by our trading surplus with the United Kingdom. In this situation the mineral trade plays a remarkable part. If one delves into the details of our transactions with the United States it will be found that, in one sense, the mineral trade is entirely responsible for the huge annual balance against the Dominion. In fact, Canada gets decidedly better than an even break on Canadian American trade, if one leaves out of account the three mineral groups, "iron and steel", "non- metallic minerals", and "non-ferrous metals".

Jan 1, 1924

By A. E. Cameron

The theory of atomic distribution of the stranger atoms in the space lattice of the solvent metal has been well developed by Rosenhain. It has long been known that the addition of one metal to another to form a solid solution increases the strength and hardness of the solvent metal. This increase is practically proportional to the amount of added substance up to the limit of solid solubility. To account for this increase in hardness and strength, Rosenhain assumes that the stranger atoms occupy positions on the solvent metal space lattice. Atomic attractions about the stranger atoms will not be the same as in the case of the pure metal, and there will thus be a disturbance of the orderly arrangement of the atoms on the space lattice, or a distortion of the lattice. Such a disturbance would interfere with the ease of slip along the planes and would thus tend to promote strength and hardness. Rosenhain notes that not only may there be a local disturbance of the lattice about the stranger atom but there may well be also a measurable change in the dimensions of the lattice as a whole. The relative amounts of local and general distortion of the lattice will depend upon the nature of the lattice itself. As Rosenhain says, "If the lattice is comparatively soft and flexible the distortion is likely to be largely local. In a stiff lattice, however, local distortion will be resisted and there will be a correspondingly increased general distortion."

Jan 1, 1927

By R. D. Brown

This article summarizes some of the principal features of the taxation of industrial mineral mining in Canada. Where the rules applicable to such operations differ from those pertaining to the production and processing of precious and base meta s (non-industrial minerals), the two sets of rules are compared. If a conclusion could be drawn from such an over-all comparison, it may be that the total tax burden on an industrial mineral mine can be considerably more onerous than on both base meta mining operations and manufacturing profits.

Jan 1, 1979

By W. T. Irvine

"The Britannia ore deposits are approximately 20 miles north of Vancouver; and occur in a prominent ridge facing Howe sound. A large ironstained bluff first attracted the serious attention of early prospectors. This; upon investigation; proved to be the outcrop of a large copper orebody. The highest outcrops were 4; 300 feet above sea-level.The original discovery was made in 1888, but no real development took place until 1902. The first mining was done in what came to be known as the Jane orebody, and some production was obtained from this in 1905. Underground exploration led to the discovery of several other orebodies. The first main adit, the 1,050-foot level, was driven to tap the ore at an elevation of 3,300 feet above sea-level. During succeeding years, however, long adits were driven from points lower down on the mountain side. These, with connecting shafts, followed the ore to horizons well below sea-level. The lowest working has now reached to 880 feet below sea-level. The property has been in almost continuous operation since its original exploitation in 1905. Until the end of 1944, 732,414,420 pounds of copper and 261,125 ounces of gold had been produced from the mine."

Jan 1, 1954

By Yi Yang, Mark Zoback

"We report laboratory studies of the time-dependent deformation of core samples from four different formations in the Williston Basin - the Lodgepole formation, the Middle and Lower Bakken formations and Three Forks formation. The laboratory tests reveal varying amounts of viscoplastic deformation in response to applied differential stress. The time-dependent deformation is generally greater in rocks with higher clay and organic content, and can be described by a power-law function. Because the magnitude of the creep strain is linearly proportional to the applied differential stress, we can utilize viscoelastic theory and geophysical logs to estimate the degree to which tectonic stress is affected by viscoplastic stress relaxation. We suggest that viscoplastic stress relaxation results in the Upper and Lower Bakken Formations act as frac barriers during hydraulic fracture stimulation in the Middle Bakken, but the Lodgepole and the Three Forks Formations are not frac barriers.INTRODUCTIONHorizontal drilling and multi-stage hydraulic fracturing in shale reservoirs are critical for successful exploitation of ultra-low permeability shale gas, tight gas and shale oil reservoirs. Characterization of the mechanical properties of the reservoir rocks is essential to understanding the behavior of rocks during drilling and completion. Previous laboratory studies have shown that the timedependent deformation in clay-rich shales can be characterized as linear/viscoelastic deformation (Chang et al., 1997; Hagin and Zoback, 2004a, b; Sone and Zoback, 2013b, 2013c). Sone and Zoback (2013c) showed that laboratory measurements of time-dependent deformation in various gas shale reservoir rocks, and demonstrated that the viscoplastic deformation of these rocks can be characterized by a power-law function. They interpreted the results in the framework of linear viscoelastic theory to quantitatively assess the geomechanical effect of viscous time-dependent deformation over engineering and geological time scales. (Sone and Zoback, 2014) further extended the theory and proposed a viscous relaxation model that can be applied to predict the continuous differential stress magnitude using the geophysical logs. They tested the validity of their model by comparing the stress prediction with the occurrence of drilling induced tensile fractures (DITFs) and the vertical hydraulic fracture penetration observed from microseismicity."

Jan 1, 2015

By J. E. Dutrizac

A pyritic Zn-Pb-Cu ore waspercolation leached with acidified ferric sulphate solutions; zinc and copper were leached, lead was oxidized, but not dissolved, and pyrtte was essentially unattacked. High zinc extractions were achieved after a few months leaching, and substantial zinc solution concentrations could be produced by recycle of the oxidized solution. The leaching rate was generally controlled by the transport of the ferric sulphate oxidant. Zinc extractions increased with increasingferric ion concentration or flow rate, but were essentially independent of the concentrations of sulphuric acid, ferrous sulphate, cupric sulphate or chloride ion. The leaching rates were insensitive to the height of the ore column once a minimum height had been exceeded (0.8-1.0 m). Elemental sulphur was the principal sulphidic reaction product, but variations in the ratio of sulphur to sulphate produced anomalous temperature effects.

Jan 1, 1979

By O. A. Ojo, N. Esmaeili

"The effects of brazing and use of composite powder mixture as interlayer material on hot corrosion resistance of brazed IN738 superalloy were studied. Brazing was observed to result in significant reduction in the hot corrosion resistance of the superalloy. However, application of composite powder mixture, which consists of additive superalloy powder, enhanced the hot corrosion resistance of brazed samples. It is also found that although the use of composite powder mixture increased hot corrosion resistance of brazed alloy, if the additive powder completely melts, which is possible during brazing, it can significantly reduce the hot corrosion resistance of the brazed joint. Elemental micro-segregation during solidification of the joint with completely melted powder mixture produces chromium depleted zones and consequently reduces hot corrosion resistance, since a uniform distribution and adequate chromium concentration is necessary to combat hot corrosion. This has not been previously reported in the literature and it is crucial to the use of composite powder mixture for enhancing the properties of brazed superalloys.INTRODUCTION Superalloys have been developed in response to the increasing demand for materials with higher resistance to corrosion and creep and also with higher mechanical strength at higher temperatures (Smith, 1981). Ni-base superalloys are predominantly used in manufacturing hot sections of gas turbine engine components. This is due to their high strength and corrosion resistance in extremely high temperature service environments which is typical for hot sections of gas turbine engines (Miglietti, 2009). The continuous demand for higher efficiency and output has resulted in the use of higher operating temperatures and gas pressure in modern gas turbine engines (Jahnke & Demny, 1983). Consequently, this has caused thermal and mechanical stresses which result in severe degradation and damage of gas turbine engine components due to creep, fatigue and hot corrosion (Zhang, Feng, & He, 2006). The decision to replace or repair damaged parts depends on the overall repair cost and expected life of the repaired components (Jahnke & Demny, 1983). However, in most cases, it is more cost effective to repair damaged parts rather than use a full replacement."

Jan 1, 2017

By C. Desmeules

"Carbon addition in the oxide pelletizing process is a big concern at the Sidbec-Normines pelletizing plant since 1976.Laboratory pot-grate testing carried out before the initial start-up of the Port-Cartier plant indicated that the nominal pelletizing grate capacity could be increased by fifteen per cent with a suitable carbon addition. Also an improved induration cycle offered the possibility of a significant energy reduction within the process with no adverse effect on pellet quality. A one-month plant scale program duplicated the lab test results and confirmed the anticipated cost saving by using these techniques. Since March 1980, Sidbec-Normines used coke addition as a current operation.This paper reviews briefly earlier laboratory and in-plant test work carried out to investigate the effects of adding carbon materials to the Fire Lake hematite concentrate, and presents operation techniques and plant results of carbon addition in the Port -Cattier pellet plant.IntroductionThe Sidbec-Normines pelletizing plant at Port-Cartier, Quebec, is designed to produce six million ton s per year of oxide pellet s. It is a Dravo-built two-line plant; one line to produce three million s tons per year of blast furnace grade pellets averaging 5.5 per cent silica, and another line of three million ton s to produce direct reduction grade pellets of about 2.0 percent silica.The laboratory pot-grate test program was conducted in 1977 at the British Steel Corporation Research Laboratories in England, with the assistance of J .E. Appleby, consultant to British Steel Corporation (overseas services) Limited.The purpose of that test program was to determine the optimum energy saving cycle and to study the physical and metallurgical effects on blast furnace and direct reduction pellets."

Jan 1, 1983

By Rui Wang, Engang Wang, En Jiang, Anyuan Deng, Xingwu Zhang, Fei Wang

In this paper, the rectangular strands of Incoloy 800 superalloy were fabricated with a pilot vertical continuous caster in Northeastern University, China. In the processing, an electromagnetic stirring (EMS) is applied on the secondary cooling zone to control the solidifying structure and segregation of elements in the strands. The solidification structure of Incoloy 800 superalloy strands were investigated at different electric parameters and casting parameters. The research results show that the EMS can effectively restrain the dendrite growth and increase the ratio of equiaxed grains in Incoloy 800 superalloy strands as applied a suitable electric parameters and cooling condition in the process of continuous casting. The evolution of dendrite crystallization in Incoloy 800 alloy strands from the surface to its center during the solidifying process was investigated with and without EMS.

Jan 1, 2014

By S. J. Cook

The system of mining statistics for Canada, as it exists today, represents the result of long years of progress, first by the Geological Survey, later and more comprehensively by the Mines Branch of the Department of Mines, and now by the Mining Branch of the Dominion Bureau of Statistics-all supplemented by the very comprehensive reports published by the several provincial departments of mines. It is the purpose of this paper briefly to state the development and present status of Canada's statistical service, more particularly in regard to information on mineral production, and to show that in its evolution continuous progress has been made in the elimination of factors tending to duplication and overlaping, with the result that the construction of an adequate statistical service has been carried out with the least possible expenditure of .public funds. For the purpose of this discussion, the subject of mineral statistics may conveniently be considered from two points of view. The technical difficulties in obtaining satisfactory and complete data from the variety of industries represented in the mining fields of Canada must be apparent to all. Methods of record-keeping are almost as numerous as mines and even the larger concerns which maintain elaborate records for their own information, often find it difficult to compile the statistical reports required of them, because the specific form of inquiry differs from the method in use in their offices.

Jan 1, 1924

By J. Donnelly, A. V. Deev

Substitution of coal and coke by renewable carbon (charcoal) is a low-risk and low-capital path to 50% or more reduction in net CO2 emissions by the steel industry. However, the high cost of charcoal and its low availability in most countries are barriers for the implementation of this approach. Development of an efficient wood carbonisation technology (slow pyrolysis) capable of producing large-volumes of charcoal from low-cost wood feed (e.g. wood wastes or forest residues) is an essential step towards the use of renewable carbon by the iron and steel industry. This paper provides a summary of the progress made over several years of R&D covering: (1) development and piloting of a new energy efficient slow pyrolysis process for production of charcoal from woody biomass at a competitive cost to the PCI coal, (2) techno-economic evaluation of the process. The main feature of the process is that the material undergoing pyrolysis is heated spontaneously without the supply of heat or air to the reactor. This makes it possible to carbonize large volumes of small-sized wood (e.g. wastes and residues) in a single reactor unit and capture high calorific value pyrolysis by-products

Jan 1, 2015

By D. W. Euler, B. J. Clauzier

"Implementation of an effective energy management system will reduce energy costs without impacting negatively on production.The energy management system must be designed to complement the operation and be integrated with the organization. It must be reliable and easy to use but most important, it must have an accurate and timely feedback reporting system to allow the operation to take appropriate action.Falconbridge Limited was one of the first three companies to be awarded the energy monitoring demonstration program in May 1987. The program is sponsored jointly by the Ontario Ministry of Energy and Ontario Hydro.This paper describes the approach taken by Falconbridge Limited to implement the Onaping Area Energy Management System.IntroductionThe objective of the project was to implement an effective energy management system, capable of reducing energy costs without impacting negatively on production.Energy management systems must be designed to complement the operation and to be integrated with the organization. The system must be reliable and easy to use, but most importantly, it must have an accurate and timely feedback reporting system to allow the operation to take appropriate action."

Jan 1, 1990