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By Raj Thamburaj, Li. Ping, Prakash C. Patnaik

"An effective prognosis system for aircraft engines may involve the application of a wide range of technologies and methodologies, which may include: - On-line, real-time and in-situ non-destructive inspection/detection/sensoring - Aircraft/engine instrumentation - Airborne data recording system - Advanced signal filtration - Data compression technologies - On-line engine health monitoring technologies - On-line engine component life usage monitoring technologies - Mission severity analysis algorithm based on life prediction and damage tolerance analysis models - Life assessment methodologies - Optimized repair/overhaul/maintenance planning - Optimization of mission assignment and homogeneous life usage - Web-enabled information delivery and sharing system - Decision making logistics This paper will demonstrate some efforts that Orenda has accomplished over the last decade in collaboration with the Institute for Aerospace Research of National Research Council Canada and the Department of National Defense. The presentation will focus on the following projects:"

Jan 1, 2004

By S. Boisvert

Risk-based Inspection (RBI) addresses the challenges associated with ageing plants by focusing the inspection effort on the process equipments with the highest risk, thereby improving plant safety and reducing inspection costs. The RBI methodology is commonly used in the oil industry through the API 581 standard. Since no such standard exists in the mining and metals industry, BPR-Bechtel has developed one using inspection data from process equipments in CEZinc. Models were developed for various damage mechanisms, such as uniform corrosion and stress corrosion cracking. The equations were organized into a user friendly software that facilitates the implementation process.

Jan 1, 2010

By Neil Schofield

"The Pine Creek gold mineralization is associated with saddle reefs and quartz and quartz sulphide veining within the Enterprise Anticline. The anticlinal structure is complex and the mineralization was considered prior to development to be dominantly strata controlled. Gold grades vary up to 160 gin 1.5 m core samples with coefficients of variation in excess of three.The estimation of ore reserves for such a deposit must account for both the geological complexity and the extreme variability of gold grade.This paper describes the structural and variogram analysis of the gold grades and demonstrates the importance of incorporating the geological model in such an analysis. Variogram interpretation is greatly improved and greater insights into the finer geological structure areprovided. Part 2ofthis work presents the application of multigaussian kriging to reserve estimation for deposits with highly variable grade and which consequently demand highly selective mining operations. IntroductionThe Enterprise Gold Mine is situated some 220 km southeast of Darwin in Australia's tropical north. Gold is believed to have been discovered there in 1869 during the construction of the overland telegraph line.From 1894to 1915, some 75 000 ounces of gold were produced from 121 000 tonnes mined mainly by Chinese leaseholders. From 1906 to 1915, government-sponsored drilling led to the sinking of the Enterprise Shaft to 79 m and several drives were developed. Mining ceased because of war.Since late 1980, Goldfields Exploration Pty. Ltd. had explored on several mining tenements near Pine Creek under joint venture with the title holders, Enterprise Mines NL. This work culminated in the development of the current mine which opened on October 29, 1985.Feasibility studies to determine the economic viability of mining were based on ore reserves generated by project geologists using a sectional polygonal approach tuned to the interpreted geological control of the mineralization.The study motivating this two-part paper covers are-estimation of the recoverable reserve s using the geostatistical approach of multigaussian kriging developed at Stanford University, (Verly, 1984)."

Jan 1, 1988

By M. Kim, M. Ha

"The effect of red mud on the melting behavior of ferronickel slag was investigated by a laboratory-scale horizontal tube furnace. Melting and softening of slag samples fluxed with different amount of red mud was examined by in-situ visualization technique at temperature range from 1400 to 1550°C. FactSageTM 7.0 was used for the thermodynamic calculation of multi component system of ferronickel slag and red mud. Liquid phase area was extended to lower temperature by adding red mud indicating its suitability as a flux material. X-ray diffraction analysis confirmed the dependency of the phase changes on the red mud content. Microscopic observation by scanning electron microscope (SEM / EDX) clarified the phase transformations from olivine to spinel along with red mud additions.INTRODUCTION Ferronickel smelting by submerged arc furnace (SAF) is an energy intensive process performed at high temperature range 1500–1600°C. During the smelting process of saprolitic nickel laterite ore with a nickel content of 2.2–2.3 pct, a large quantity of ferronickel slag is being produced that account for 97 pct of ore charged. To achieve ferronickel grade of 15–20 pct Ni, electrical energy of 80 to 85 MW is used for the melting and reduction of nickel oxide (NiO) and iron oxide (FeO) in the ore (Rodd et al., 2010). Unreduced components, mostly MgO, SiO2 and partly FeO are removed from the furnace in a liquid slag form by a tapping operation. Due to the high melting temperature, forsterite (Mg2SiO4) based slag containing approximately 10 pct FeO requires typical process temperature of 1600°C. Flux in metallurgical process is a medium that decreases melting and operating temperatures while it increases fluidity of the liquid slags. Calcite and fluorite are examples of flux materials used for the ironmaking, steel refining and continuous casting process. Oxide systems based on CaO - CaF2 - SiO2 - Al2O3 - MgO cover most of the slag composition in ferrous metallurgy accordingly. Crucial operating factors for ironmaking and steelmaking slags are basicity (typically CaO/SiO2 ratio), viscosity and impurity levels. These are extensively controlled by the fluxes. General metallurgical fluxes such as limestone, dolomite and calcium fluoride are abundant in nature and supplied to steel mills at low prices. Meanwhile, in copper flash smelting process, silica is supplied with copper concentrate to remove iron oxide (FeO) generated from sulfide oxidation. FeO - SiO2 binary system formulates eutectic area at 25–38 pct of silica that has low melting temperature below 1205°C. Fayalitic system (Fe2SiO4) that has low viscosity (0.1 Pa·s) (Park et al., 2011) facilitates easy separation of slags from molten sulfide mattes. Recently, copper plants actively utilize recycled raw materials as a flux. Various recycled glasses are ground and fed to copper smelting process as a partial replacement of silica ore. Applying industrial wastes to smelting processes is advantageous since the operators can reduce the production cost remarkably. Not to mention the consumption of recycled materials can ultimately minimize the environmental risks and the waste management costs. The authors, therefore, investigated the reasonable waste materials that can be effectively used for ferronickel smelting process. Prerequisites for potential fluxing materials are non-recyclable property, low transportation cost and excellent performance as a flux."

Jan 1, 2017

By Neil Campbell

"The Pine Point area is on the south shore of Great Slave Lake, 510 air miles north of Edmonton and J JO miles south of Yellowknife, N.W.T. The occurrence there of lead and zinc was reported in J 899 by R. Bell (5) of the Geological Survey of Canada, and in the following years several claims were staked and some prospecting was done. In 1928 Atlas Exploration Co. took over the property containing the discovery occurrences. In 1929 The Consolidated Mining and Smelting Company of Canada Ltd. (""Cominco"") and Ventures Ltd. participated with Atlas in forming the Northern Lead-Zinc Co., which, under the direction of J. M. Bell, carried out 24,499 feet of drilling in the discovery and surrounding areas. Two shafts and many surface pits were also sunk. This work showed that the discovery deposits contain about 500,000 tons of lead-zinc ore, but no new orebody was found.In 1936 D. F. Kidd (11) drew attention to the highly significant space relations between the base-metal discoveries at Pine Point and the projections of certain major Precambrian faults mapped earlier by C. H. Stockwell. Geological work by Cominco in 1940 and subsequent years suggested the presence of mineable deposits within a belt of land including part of the area of earlier field work and extending far beyond it. Between 1946 and 1954 exploration financed by Cominco and Ventures Ltd. included 182,950 feet of diamond drilling, 383 feet of sinking, and 240 feet of drifting, raising, and crosscutting. This work was successful in finding substantial quantities of new ore in places where bedrock is completely concealed.The topography is one of low relief, characterized in many places by swampy muskeg and shallow, marl-bottomed ponds. The area where ore has been found is generally higher ground which, though not well drained, is comparatively dry. It is also marked by raised beaches and a few sand dunes overgrown by small spruce and pine. Bedrock is generally overlain by a variable thickness of hard, glacial boulder clay. This in turn is covered by silt, sand, and gravel, probably deposited from the waters of Great Slave Lake, which formerly extended many miles beyond its present southern shore."

Jan 1, 1949

By J. G. Conaway, P. G. Killeen

"Gamma-ray spectral logging, a useful technique for uranium exploration and evaluation, has generally been underutilized by the Canadian mining industry. Provided that the technique is properly applied, it is capable of yielding reliable quantitative information regarding the distribution of uranium and other radioelements along the borehole under most conditions.In practice. there are numerous factors which potentially can degrade the quality of the log and thus any quantitative interpretation based on it. Fortunately, the appropriate choice of logging equipment and technique can avoid many such problems, and corrections can be applied to the data to compensate for most of the others."

Jan 1, 1980

By George J. Simandl, Suzanne Paradis, Kirk D. Hancock, Jana Simandl

Traditional prospecting and boulder tracing are the two most important field techniques used in exploration for magnesite deposits hosted by sedimentary rocks. Consequently, success depends largely on the prospector's ability to identify magnesite. A density agent called sodium polytungstate (3Na2W04·9WOj'HPJ was successfully used to determine the presence of magnesite in sedimentary carbonate rocks of southeastern British Columbia. A rapid field method was developed and tested. This method permits discrimination between limy dolomites, dolomites, magnesite-bearing dolomites and magnesite-rich rocks.

Jan 1, 1993

By Richard K. Komarek, Antonios Zavaliangos, Roman T. Dec

Current industrial compacting and briquetting practices are largely based on trial-and¬error techniques. This paper introduces a two dimensional finite element model of compacting/briquetting process in the roller press. Compared with other modeling techniques used in the past, finite element method offers the most versatile approach because it incorporates adequate information about powder behavior, geometry and frictional conditions and offers predictions for the density distribution, velocity field, stress distribution, roll force, roll torque and other important process variables. More over, when the model includes elasticity, it offers predictions on the internal stress state in the briquet after its exit from the pressing zone. This enables to perform realistic computer experiments which are helpful for establishing the pressing system design, forming cavity geometry and process conditions necessary to produce compacted or briquetted product with the desired properties.

Jan 1, 2004

By A. Aubin, H. Yang, G. Zaluski

The Athabasca Basin of northern Saskatchewan and Alberta is an exceptionally rich metallogenic region, hosting more than 2.8 B lb U3O8, of which over 927 M lb U3O8 have been mined out since extraction first started in the late 1970’s. A detailed compilation of several empirical features of 85 deposits located within the basin was conducted in order to understand the distribution and variability of the geological characteristics of the mineralization and its associated alteration. A new empirical classification was devised based on four parameters: 1) geometry of the mineralization (dimensions and relation to the unconformity surface), 2) size, grade and metallurgical complexity of the mineralization, 3) lithostructural setting, and 4) extent and nature of associated alteration haloes. This compilation defines the footprint characteristics of the Athabasca Basin deposits, which guides decision-making processes from early exploration and discovery to resource expansion and extraction.

Jan 1, 2020

By S. Shairp

At the Hudbay zinc pressure leach plant, filtration and washing of the second stage leach slurry takes place on a vacuum belt filter prior to disposal to tailings. Due to periods of poor filterability, laboratory studies were undertaken to investigate the effect of temperature of the filter feed slurry, and to compare filterability to the resulting cake particle size distribution.

Jan 1, 2014

By D. A. Barr

"Most of the lode and placer gold production in the Canadian Cordillera has been derived from mines and placers in the Intermontane and Omineca belts. Gold has been produced from rocks of Precambrian to Eocene age, but the preferred host environment contains Upper Paleozoic to Upper Jurassic eugeosynclinal or arc-type sedimentary and volcanic rocks adjacent to plutonic complexes which have a wide variety in both size and composition. Auriferous quartz lodes occur in fissures and shear zones which are commonly subsidiary to strong fault zones. In common with most vein-type deposits, structural complexities are an essential part of the mine environment.Gold production from the Canadian Cordillera to the end of 1978 totals 35.0 million ounces, of which 47 per cent has been produced from placer mining, principally in the Klondike and Cariboo districts. The balance has been derived from lode gold (80 per cent) and base metal (20 per cent) mines.Gold reserves in producing mines and deposits committed for production as of January 1, 1978 were 87.4 tons, or 21.6 per cent of total Canadian gold reserves contained in all types of deposits. Although more than 100 lode mines have operated in the Canadian Cordillera since the turn of the last century, over 75 per cent of the lode gold produced by 1978 was recovered from five mining camps, namely the Rossland, Hedley, Bridge River, Premier and Barkerville.The average grade of the principal producers in these camps was about 0.45 ounce of gold per ton. Individual camps yielded from 3 to 8 million tons during their operating lives, which varied from 28 to 43 years. The last of these mines ceased operating in 1971.Most of the total lode gold production has been derived from quartz veins, frequently with associated carbonate and ankerite, occupying fractured and faulted zones in Mesozoic volcanic and sedimentary rocks closely associated with a variety of intrusions. A review of the literature suggests that several deposits may have evolved by remobilization of ore constituents from earlier concordant gold-bearing formations. The principal metallic minerals in the deposits are native gold, electrum, tellurides, pyrite, arsenopyrite, pyrrhotite, sphalerite, galena and chalcopyrite.As the mineralogy suggests, many of the Cordilleran lode gold deposits have yielded important co-products or byproducts, including silver, copper, lead, zinc, cadmium and tungsten. Significant by-product gold production has also been derived from porphyry copper, volcanogenic, replacement and pyrometasomatic deposits, particularly in recent years.No major lode gold discovery has been made in the past 67 years, although little exploration activity for gold has taken place during the last 30 years. Several relatively small lode gold and gold replacement deposits have been discovered in recent years, either serendipitously (Chappelle) or on very low initial budgets (Northair and Carolin). Based on well-established precedents, one or more of these may eventually be developed into a large mine.A detailed study of the Canadian Cordillera gold deposits based on recent genetic models could prove rewarding, not only in up-dating information on their origin and depositional characteristics, but in stimulating the search for undiscovered gold deposits, in the Cordillera and other parts of Canada."

Jan 1, 1980

By Matthew Scott

Introduction The refining of precipitate is the final stage of all the processes involved in gold mining and cyanide milling, by which the precious metal is at last obtained in a concentrated form, which can be accurately valued and marketed. Possibly one ought to say, conveniently shipped, for accuracy in valuation depends in many instances on a toughening treatment given the bars as received at the Mint so as to obtain a homogeneous metal that lends itself to representative sampling; which, of course, entails a surcharge on the regular Mint charges for the extra work necessarily undertaken. There are several methods of refining zinc-gold precipitate, each with its advocates; the method employed depending not always on the quality of the bullion produced but on the local exigencies of the case in point. These methods are more or less detailed in various textbooks and it is not the purpose of this paper to discuss them, but to confine ourselves to the specific case as stated in the title of the paper. At the outset, it behooves the writer to express his thanks to Mr. Brigham, the General Manager of the Hollinger Mines, for the kindly consideration and encouragement given in developing this process. This will be better understood when one considers the immense values involved, tending towards conservatism in practice, and making one chary of radical innovations. This process has been in satisfactory operation now for about two and-a half years, during which time over twenty-five million dollars value in fine gold has been produced, so that it may be reasonably held that the process is successful.

Jan 1, 1931

By Peter A. Bevan

"In massive and semi-massive deposits, it is essential to take samples continuously for specific gravity determination as well as for assays of the various metals of interest. Failure to use specific gravity in mixed deposits of high density contrast will result in incorrect determinations of the average grade.Graphs and linear equations of specific gravity against the grade of one metal are not considered accurate enough in a multi-mineral deposit, but appear to be very satisfactory in a theoretical one-sulphide/gangue mix. Specific gravities based on base-metal values only in massive sulphide deposits will result in underestimating the effect of low grade areas on the average grade and also cause a reduction in the calculated tonnage.IntroductionBy definition, a base-metal assay is the percentage of metal by weight contained in a sample, whether it be a soil or silt sample, a grab, chip or channel sample, or a section of diamond drill core.In those cases where there is a series of contiguous samples, say in diamond-drill core, the average grade may be required of the various assays that are above a desired or required cutoff grade.Internal low grade or waste can be included if the assays one side or the other are used to ""carry"" the lower grade material and the resulting average grade is above the cut-off grade. To determine the average grade, the individual assays are ""weighted"" by multiplying these values by their respective lengths, adding up the cumulative assay times length and dividing by the total length. This method is essentially a weighting by volume, because the core diameter is constant and is common to all the samples being considered for estimating the average grade . If some of the core samples have much higher specific gravities than others, and the specific gravities are not used in the weighting process, the resultant average grade will be over-estimated or underestimated, depending on the grade of the heavier sections. When core assays of approximately the same specific gravity or weight are averaged by length, the error in the weighted estimation of the average grade is negligible."

Jan 1, 1993

By R. H. McCorkell

Measurements of radon in air and aqueous solutions can be affected by leakage from vessels in which samples and standards are kept and by absorption and later release of radon by the materials of these vessels. The author had received various oral communications concerning the se processes : e.g ., that natural rubber and greases absorb large amounts of radon, whereas silicone rubber and grease do not; and that radon is readily lost from polyethylene bottles and that inverting glass bottles containing aqueous samples reduced radon loss from them . However, the results of actual tests and quantitative data showing these effects were not available. For this reason, it was necessary to make numerous measurements of the leakage and absorption of radon in the course of designing apparatus and methods for measuring radium and radon concentrations. It was thought that the data obtained might be of use to others, and consequently they are compiled in the present note .

Jan 1, 1980

By A. S. Dawson

"IntroductionTHE PURPOSE of this paper is to describe the results of a preliminary investigation of a method thought to be useful in interpreting geological structures in un-metamorphosed sedimentary rocks. The writer is not aware of the method having been described or investigated previously, although no thorough search of the literature has been made.The method to •be described is based on the assumption that, in argillaceous sedimentary rocks, certain ceramic properties are diagnostic for certain beds within areas of variable limits.Two ceramic properties• have been investigated: pyrometric cone equivalent (P.C.E.), and bloating characteristics of shales. The enquiry has been directed toward testing the usefulness of these properties in determining the following:A -The correlation of shale beds and, by inference, of coal seams, sandstone beds, or other such structures associated with them.B.-The location of contacts between marine and non-marine shales where lithological, palaeontological, or other evidence is lacking.Limitations of time and facilities have prevented a thorough investigation of this problem. The results given in the present paper are preliminary only. It is hoped, however, that they will occasion discussion or even lead to more thorough investigation of the method by individuals or organizations.There are, admittedly, various limitations to the proposed method. It is thought to show some promise when used in conjunction with the well-known and established methods used in stratigraphic correlation and, more particularly, when the conventional methods are not applicable."

Jan 1, 1952

By Morgan Schauerte, Laura Raimondi, Mariel Palomeque

Executives in the mining industry are facing dramatically changing market expectations on reporting and transparency regarding the environmental and social impacts of projects, supply chains and products. Companies increasingly need to disclose the governance procedures they have in place to ensure communities, investors, employees, and Indigenous partners are effectively managing social and environmental risks. These disclosure requirements begin during exploration and carry through to all stages along the project life cycle. This type of environmental, social and governance (ESG) disclosure is referred to as ESG performance by the investment community. ESG is not a new concept, and it builds on and is intertwined with many concepts such as corporate sustainability, corporate social responsibility, eco-efficiency, triple bottom line thinking, life cycle management and many others. This paper will explore how mining companies can develop a credible ESG governance approach and strategy that will reduce risk, open opportunities, and create value. This paper will summarise ESG trends and drivers, discuss the economics and investors’ perspective towards ESG, and outline leading ESG standards and guidelines of interest to investors, regulators, communities and other stakeholders. Linkage of ESG to global sustainability efforts such the United Nations Sustainable Development Goals and Global Compact will also be addressed.

Jan 1, 2023

By K. Meshinchi Asl

In this study the effects of T4 and T6 heat treatments on microstructural characteristics of AZ91 alloy containing Rare Earth elements have been investigated. Formation of intermetallic Al1 1RE3 needle shape particles which have a good thermal stability reduces both formation of ß(Mg17A112) and discontinues precipitation in AZ91 alloy which are dominated at the grain boundaries and are responsible for poor mechanical properties specially in elevated temperatures. For AZ91-RE samples both T4 and T6 heat treatments led to a continuous precipitation of ß particles at the grain boundaries after aging. However, in AZ91 samples (with no Rare Earths) precipitation was discontinuous at grain boundary areas. This type of precipitation is one of the main reasons of poor mechanical properties of this alloy at elevated temperatures.

Jan 1, 2007

By A. M. Esteves

This paper offers an overview of local content policies and practice in the mining sector. Specifically, the paper aims to answer the question of how national and regional governments, industry and civil society can work together to seek an optimal outcome while pursuing their diverse objectives. The paper begins by defining local content and its scope at the subnational level. Specific recommendations for the design of local content policies to mitigate social, economic and governance risks are developed. The document then offers some recommendations regarding the role of partners in design, implementation, monitoring, and enforcement of local content policies.

Aug 1, 2013

By J. A. Finch

"This paper describes major technical developments in rod mill design and operating practice since its introduction into the North American minerals industry over fifty years ago. The basic operating characteristics of the wet, overflow rod mill are described, and significant operating variables are reviewed in terms of their effects on mill power draw, power efficiency, and practical aspects of circuit operation. Key factors for improving the economic performance of rod milling circuits are identified. IntroductionThis paper summarizes the findings of a detailed review of available technical information on the operation of rod mills. One of the basic problems in historical comminution testwork has been the lack of a standard measure of circuit performance. The Bond Operating Work Index, not introduced until after 1950, has proven of immeasurable value in this regard, but first has to be carefully considered in terms of its utility and limitations. Its prescribed use is described in a later section of this paper.During this review, it became apparent that rod mill performance is generally not well understood. Because of combined interactions, the effects of different operating variables may be difficult to assess, and even at times appear erratic. It is obviously difficult to rationalize plant testwork or circuit adjustments when the results are highly unpredictable. The purposes of this review, therefore, were:a) to establish what basic facts have been learned about rod mill performance;b) to define some genera l guidelines for efficient rod mill design and operation; and,c) to establish a basis for specific recommendations for plant tests or adjustments with minimum risk, and maximum potential for circuit performance improvement."

Jan 1, 1986

By M. Gagné, F. E. Goodwin

The mining industry represents a significant investment in infrastructure of which steel plays a key role. Many structures in a mine are made of steel including shaft structures (buntons, station steelwork and headgear); stope structures (roof supports, pipe hangers); haulageway structures (ore transfer stations, electrical stubbies); and surface structures (plant buildings, tank supports, pipe gantries, conveyor belts, stacks, stockpile structures, stairways and railings). Maintenance of structural components can often be difficult because of the environment, including those where corrosive fumes persist, or limited access, such as in shafts where access is limited, or to short maintenance shifts or where limited working space is available. Thus a cost-efficient, long-lasting and maintenance-free protection system for steel should be specified. Galvanizing provides the required high-quality, long-term corrosion protection to steel. Galvanizing provides protection in two ways, first as a physical barrier to corrosion and secondly by means of cathodic or sacrificial protection that is unique to zinc. The dual nature of corrosion protection provided by galvanizing significantly extends the service life of steel even in the most challenging environments. The unique corrosion protection properties provided by galvanized steel will be highlighted with global mining application case studies.

Jan 1, 2015