Search Documents

By Alisa M. Caswell

Outline: 1. Syncrude: Who are We? 2. Energy Use at Syncrude 3. Historical Energy Focus at Syncrude 4. Case Studies for Process Variable Monitoring 5. Extraction Flood Water Temperature Management 6. Fired Heater Tuning 7. Critical Factors for Success Syncrude: Who are We? ?Syncrude is a Joint Venture Operating Company with one product: Synthetic Crude ?Production Capacity: 350 kbbls/day ?Primary Energy Sources: ??Fuel Gas + Natural Gas ?? Coke ?? Electricity ?? Diesel

May 1, 2008

By Eric R. Skonberg

"Technology exists today to blind drill a mine shaft 20 feet in diameter, unlined, over 3,000 feet deep. These shafts must be lined in the most economical, safe and expedient manner possible. A new technique of stacking precast concrete cylindrical sections in the unlined shaft has been developed to yield a dry and hydrostatically lined shaft .These sections must withstand an external radial pressure of 3,000 feet of water yet take up as little room as possible in the shaft . Using high-strength concrete, wall thicknesses may be kept at 2 feet. The outside diameter of the sections has been chosen to be 18 feet to allow for some annular space between the liner and shaft wall. The concrete sections are produced in segments 10 feet long weighing 75 tons each. During drilling operations, the concrete sections are cast and cured. After drilling operations are complete, a headframe is situated over the shaft. The unlined shaft remains full of fluid. A special liner running tool is mated with the section in three steel ports at the bottom of the section. The section and running tool are lowered into the hole, and the tool is disconnected and returned to the surface. Subsequent sections are lowered and stacked using the same operation. Grout is placed behind the liner to result in a dry shaft."

Jan 1, 1981

By Eric Best

"In the past two to three years, all continuous mining machines at the Potash Corporation of Saskatchewan Mining Limited, Lanigan Division, have been changed over to a new cutting pattern using 1 -inch- and 1-3/l6-inch-diameter self-sharpening pencil bits. The bits are arranged in a cone-type pattern across the face on 2 1/2 -inch and 3-inch spacing. The result is that the ore is removed by chipping and flaking. Previously, rap-lock bits were used, with the pattern being several bits in single rows at wide spacings. The cutting action was grinding and breaking.Besides improved penetration rates and lower bit costs, there are many other advantages. The ore size is much smaller, resulting in less wear and tear on conveyors and other associated equipment. Feeder-breakers are no longer routinely set up at the head end of every extensible belt, as the banana-shaped chunks of ore that used to require breaking are no longer produced. Also, less dust is generated by the cutting heads and fewer stops are required for bit changes. Even the mill operation has been improved, as fewer fines are produced.Further improvements are still sought after, but, all in all, the new cutting pattern is considered to be a giant step forward from the old method."

Jan 1, 1981

By Yufeng Yao, Robert P. Lowell

Abstract - Conductive heat flow anomalies associated with hydrothermal sulfide mounds on the seafloor have been studied. Sulfide mounds tend to focus conductive heat flow because sulfide minerals have a greater thermal conductivity than country rock. The topography of the mound above the seafloor, however, leads to a reduction of heat flow, particularly near the center of the mound. Because the focusing effect is constant, whereas the topographic effect decreases with distance away from the center, the focusing effect dominates toward the edges of the mound. The magnitude of these effects depends upon the conductivity contrast and the height/radius aspect ratio of the mound. Conductive heat flow anomalies at sulfide mounds also result from fluid circulation within the edifice. For the active and relict mounds at the TAG hydrothermal field, which have an aspect ratio of approximately 0.3 and a conductivity contrast of 3, the heat flux through the center of the mound should be roughly 70% of the background heat flux. The maximum effect of heat flow focusing is to increase the heat flux by about 30% above background. By comparing these effects with conductive heat flow data at TAG, we find that advective processes dominate conductive heat flow at both the active and relict mounds. Advective circulation can also give rise to much larger lateral and vertical temperature gradients than would result from conduction alone.

Jan 1, 1999

The effect of long term exposure of full size bolts to corrosive environments is presented. A special test rig was used to test four bolts under different loading conditions. Four, X-grade identical profile bolts, each of 21.7 mm core diameters (23.7 mm full diameter) were subjected to prolonged corrosion testing using acid sulphate water. The pH value of the circulated water varied between 3.4 and 4.3. The corrosion exposure test period lasted three and half years. Two bolts were axially loaded to 10 and 20 tonnes force respectively, the third bolt was subjected to a 360 Nm torsion load and the fourth bolt was left unstressed to act as a reference bolt. After the test period ended, the bolts were stripped of their corroded coatings and weighted for weight loss. The diameter of each bolt was subsequently measured, and the loaded bolt samples were first tested non-destructively for tensile cracks and then tested for tensile failure. No cracks were found on post corrosion bolts tested non-destructively. The failure strength reduction on all four post-corroded bolts was significant, varying between 21% and 39%. The onset of corrosion was not confined to the targeted mid-section length of the bolt, however, the severest corrosion occurred at the anchored ends of the bolts.

Aug 1, 2013

By R. Maxwell

"At Opemiska Copper Mines we have, over the past four years, operated 300 cu. ft. and 700 cu. ft. flotation cells as roughers, scavengers and cleaners and found them competitive with conventional flotation cells on a cu. ft. basis on all phases of flotation.The economics are very much in favour of the large cells for the following reasons:Power consumption is 35 to 40%, of conventional machinesMaintenance cost is about 20 to 25% of conventional machinesSpace required is about 30 to 35% of conventional machinesInstallect cost is about 40%, of conventional machinesTo put the above in more concrete terms below is what we are doing at Opemiska:1. Increasing mill capacity from 2000 to 3000 T.P.D. and will use only 5Cff, of the flotation space for 3000 tons that we used for 2000 T.P.D. with conventional flotation machines.2. Will require only 10 flotation cells for 3000 tons against 85 conventional cells for 2000 tons.3. Cells will be, one 2000 cu. ft. rougher, six 700 cu. ft. scavengers (2 banks of 3 each) and one cleaning circuit using three 300 cu. ft. cells.You will note that in this 3000 ton per day plant, we are going to have only ten cells. Had we put in conventional cells for this tonnage, we would have needed 120 cells."

Jan 1, 1970

By d&apos, F. Elia

Hot cracking of magnesium (Mg) alloys during welding creates a barrier to enhancing the use of these alloys in automotive applications. As a result, it is imperative to understand the mechanisms responsible for hot cracking of Mg alloy welds in order to develop means of eliminating this problem. In this study, the hot cracking susceptibility of AZ91E and AE42 magnesium alloys were assessed using the moving torch Varestraint test method. Plates of 3 mm thickness were extracted from AZ91E and AE42 ingots and subsequently tested. Quantitative cracking data in terms of maximum crack length (MCL) was used for evaluating the cracking susceptibility. Scanning electron microscopy was carried out. The results suggest that AE42 showed a higher resistance to hot cracking in comparison to the AZ91E alloy. This was attributed to the difference in microstructure between the two alloys. In the fusion zone and HAZ of AE42, the brittle needle-like A1IIRE3 phase was seen to decompose to the more ductile particle-like Al2RE phase, thereby increasing the alloy's resistance to hot cracking. In contrast, SEM fractography revealed that brittle A16Mn and Mg17A112 intermetallic particles segregated to grain boundaries and triggered hot cracking in AZ91E.

Jan 1, 2011

By A. Mykytiuk, I. E. Puddington, W. D. Macleod, F. W. Meadus

"A laboratory-scale continuous procedure for the up-grading of naturally occurring tin ores, based on the principle of spherical agglomeration, is described. High recoveries are indicated. A proposed second stage suggests useful fractionation steps.IntroductionA LABORATORY-SCALE batch process for the upgrading of a tin ore using the principles of spherical agglomeration has already been described (1). This procedure consisted of milling, for about an hour, a precrushed ore with at least 200 per cent water, 0.2 per cent of a reagent such as tall oil (to render the de-sired ore particles hydrophobic) and about 3 per cent of a viscous petroleum oil. The feed material passed an 8-mesh Tyler sieve, and the percentages of re-agents are based on the dry weight of the feed. Du-ring the grinding, the hydrophobic particles transfer into the oil phase to produce coherent semi-solid bodies while the gangue stays preferentially in the aqueous phase. The concentrate can be separated from the gangue easily by a mechanical operation. Using an ore containing about 0.3 -0.5 per cent tin, grades of from 1.5 to 7.0 per cent were obtained by varying the pH of the system. Recoveries fell from about 80 per cent to as low as 50 per cent as the grade in-creased."

Jan 1, 1966

By K. Oishi

We have developed a 76Cu-3Si-21Zn alloy "ECOBRASS®" containing no lead. When 3% Si is added to a 78Cu-22Zn alloy, kappa and gamma phases participate uniformly in the alpha matrix. When being machined, stress concentrates on these hard phases, namely kappa and gamma, and thereby lowering the required cutting force and yielding segmentalized chips without lubricant. Kappa and gamma phases transform into beta phase under high temperature, which makes it easier to extrude and/or forge the alloy. When 0.08% P and 50 ppm Zr are co-added, the grains of ECOBRASS® castings are refined significantly to become as small as several dozens of micrometers. The grain refinement by the co-addition of P and Zr improves castability, tensile strength and elongation of ECOBRASS® castings. Meanwhile, the lead leachate from an ECOBRASS® water meter, field-tested in pH 6.8 drinking water for one year, was less than 5 ppb without correction. No indication of dezincification corrosion was observed, either. ECOBRASS® is equally suitable for rods, forgings and castings, and makes it possible to produce a complete set of plumbing parts (valves, faucets, etc.) by its own. This way, not only improving recyclability, ECOBRASS® also realizes size and weight reduction due to its good corrosion resistance and high strength.

Jan 1, 2007

By J. Day, Matthew X. Yao, Lijue Xue

Hardfacing overlays are commonly applied on the shroud Z-section of turbine blades for enhanced wear resistance. Among various processes that are used to apply the hardfacing overlays, the plasma transferred arc (PTA) welding process offers several advantages including lower heat input, less base material dilution, rapid process time, and reduced operating cost associated with the capability to apply materials in the powder form. The development of a robust PTA process is crucial for overlay performance and repeatability, particularly in the aerospace industry where a quality intensive manufacturing environment prevails. For this reason, the Taguchi method of experimental design was selected to develop a test plan. A 4-factor 3-level (L9) orthogonal array (OA) was used in the experiment. The L9 OA allows for a more detailed (3 level) investigation of critical process parameters, namely plasma gas flow rate, traverse speed, powder feed rate, and arc current. Two hardfacing materials, Stellite 694 and Tribaloy T-800, both Co-based wear resistant alloys, were investigated by deposition onto a cast IN738 Ni-based superalloy substrate. Performance measurements of the hardfacing deposits included deposit hardness, substrate hardness, deposit density (porosity), degree of cracking/inclusions, and a quantified visual inspection. The procedure resulted in optimized PTA hardfacing parameters for both Stellite 694 and Tribaloy T-800 on IN738 turbine blade material.

Jan 1, 2004

By A. G. Matyas, B. Wasmund, R. C. Francki, K. M. Donaldson

"The construction of large. high-power electric furnaces has been an important factor in the growth of electric smelting technology . New developments in the design and operation of electric furnaces have been spurred by the escalating cost of electric power and increasingly stringent environmental constraints. Key areasofprogress include the application of high voltage to enhance furnace productivity; the installation of novel furnace cooling elements and robust binding systems to extend furnace life; development of process schemes to reduce power consumption by preheating and prereduction of the charge; and environmental control improvements for handling fine dusty feedstocks, and for furnace sealing.This paper reviews these developments and outlines a systematic approach for their application in the custom design of new or retrofit electric furnace facilities.IntroductionThe use of electric smelting furnaces has continued to progress during the last decade. Electric furnaces offer high throughput capacity and productivity. In addition, they produce minimum environmental impact, as the furnaces can be readily sealed, and only a small quantity of off-gas is generated. Electric furnaces present the most favourable choice of smelting technology where high process temperatures in excess of about l400°C are required.Their application is burdened by the escalating cost of electric power, hence it is important to seek new opportunities through further technological development. This paper reviews recent developments in the design and operation of high-power electric smelting furnaces, in the following areas:"

Jan 1, 1993

By A. Piche, J. Nantel

"This paper describes the recent developments in Canada toward the establishment of a Canadian Centre for Mining Automation and Robotics, at McGill University and École Polytechnique in Montreal. The role of the Mining Association of Canada (MA C) and of the National Advisory Committee on Mining Automation will also be reviewed. IntroductionIn order to remain competitive, the mining industry must increase its productivity and reduce its costs. In the last two decades, this objective has been achieved through mechanization. From now on, any further improvement in productivity will be gained through increasingly more automated mining equipment.Recent international developments following the Versailles Economic Summit in June 1982, having given rise in Canada, to a renewed interest in applications of robotics and automation to mining.The mineral industry in Canada is at a crossroads. Competition in emerging from everywhere: lower grade ore bodies, increasing distances between viable mines and markets, third world massive production of certain commodities, substitution of "" space age"" materials (ceramics, plastics, composites, etc.) for metals.On the positive side, it is generally believed that present mineral commodities, i.e. base metal, gold, iron, industrial mineral s, etc ., will continue to be in high demand for centuries to come despite substitution. New applications for conventional metals will be found and the enhancement of certain properties of these conventional metals mean continued demand. For some mineral commodities, there will never exist an y substitute."

Jan 1, 1988

By J. E. Tupper

"This paper will discuss strategies for the introduction of computer technology in the mine environment. More specifically, it will focus on issues such as: (a) make or buy; (b) programmer less mines; and (c) support from corporate groups.The paper relates these strategies to systems for mine operations. These will be illustrated by considering the implementation of some phases of these systems at Teck Corporation.IntroductionThis presentation addresses some of the major considerations in a strategy for mine computerization and then relates these considerations to the computerization cycle and Teck Corporation.Strategy is defined as a conceptual framework or plan to accomplish a goal. For purposes of this paper, the goals can be more simply defined for operational purposes as either increasing revenue or decreasing costs.The strategy will allow us the framework for measuring tactical decisions such as computer and software acquisitions.The Mine Life CycleTo start with, let us look at the mine life cycle from a computer systems point of view:-Exploration-Property Development-Feasibility-Construction-OperationFrom a systems point of view, the exploration cycle is oriented to geophysical and geochemical computing. Property development starts with drilling and building the geological data base. The feasibility cycle includes all stages of evaluating the decision to proceed with mine development: ore reserve calculations; mine planning; and financial projections. Construction includes project management and project accounting systems. Systems required for operation are those needed by personnel at the mine site."

Jan 1, 1982

By C. J. Clayton, A. J. Haynes, D. A. Hickson, B. Thiele

The Meadowbank Gold Project, formerly owned by Cumberland Resources Ltd. and currently owned by Agnico Mines Ltd., is currently being developed approximately 70 km north of Baker Lake, Nunavut, in the eastern Canadian Arctic region. The Meadowbank Gold Project currently consists of a series of gold-bearing deposits within relatively close proximity to one another, which are planned to be mined primarily as a truck-and-shovel open pit operation using conventional gold milling and extraction. The mining plan indicates that approximately 20 million tonnes of ore will be mined over a mine life of eight to ten years. The operation will generate approximately 160 million tonnes of mine waste rock and about 20 million tonnes of tailings. The site is located in an area of continuous permafrost with mean annual average air temperature of -11°C and average annual precipitation in the range of 100 to 200 mm. Lakes cover a large portion of the site, including some of the ore deposits. The location of the site and the physical environment pose challenges to development. This paper presents some of the designs considered to effectively manage and utilize the waste products of mining at the project. Note that volumes, tonnages, construction concepts, and data presented in this paper are accurate for the time of writing and are subject to change and modification as the project progresses, additional modelling is carried out, and additional data are obtained.

Jan 1, 2007

By Farid Mirahadi

Forecasting productivity of construction operations is a difficult but crucial task in planning construction projects. Over the past decades, many models have been developed to forecast productivity for different construction operations. Models made up of several functional relations and controlled by a specific number of control rules are more in line with human reasoning and logic. Neural-Network-Driven Fuzzy Reasoning (NNDFR) structure as one of these models shows a great performance for modeling datasets among which clear clusters are recognizable. Lack of the compatibility of conventional NNDFR with fuzzy clustering algorithms besides the insufficient attention paid to the optimization of number of clusters in this model, created a potential area for further research. The main contribution of the proposed model is to develop a modified NNDFR system to model construction data. To this end, Fuzzy C-Means (FCM) algorithm is substituted for K-means in NNDFR structure, and its parameters such as the number of clusters and weighting exponent are optimized through genetic algorithm. The proposed model is further verified through simulation of a construction operation in which several qualitative and quantitative factors are considered. Its implementation to the case study shows a considerable improvement of model performance with lower Mean Squared Error (MSE). The developed model assists researchers and practitioners in utilizing historical construction data to forecast productivity of construction operations with a high accuracy that could not be obtained by traditional techniques.

Aug 1, 2013

By M. J. Young, C. A. Aird

"The Gem molybdenum prospect is situated at the head-waters of Clear creek, between the Fraser river and Harrison lake, about 30 miles north of• Harrison Hot Springs, B.C. Clear creek follows a deeply eroded fault zone southwesterly through the center of the claim group. Elevations range from 2,000 feet in the creek bed up the steep slopes flanking the creek to a height of 5,500 feet. The property lies within an area underlain by schists and gneisses which strike from north to west in a broad fold plunging steeply to the northeast. This metamorphic complex has been invaded by numerous bodies of grano-diorite, much of which is gneissic. A granite plug, roughly 2,400 by 4,000 feet in size, has intruded this broad fold just west of Clear creek and encloses a circular breccia pipe 1,500 feet in diameter. In the breccia pipe, fragments of metamorphic rocks, granite and quartz monzonite porphyry are firmly cemented in a matrix of quartz monzonite porphyry. All the above rocks are cut by numerous fractures filled by vuggy quartz veins, many of which contain molybdenite. Attentien was first drawn to the area by a quartz vein, 18 inches in width, known as the Gem vein, which consists of several laminated bands of quartz and molybdenite. Since 1964, exploration efforts have been directed toward attempting to outline a large, low-grade type of molybdenum deposit."

Jan 1, 1969

By Sadan Kelebek, S. O. Fekete, Gerhard W. Heinrich, Peter F. Wells

"For many years, rejection of pyrrhotite at the milling stage has been a viable method for sulphur dioxide abatement. Pyrrhotite rejection options have included the use of selective pyrrhotite depressants in flotation; a depressant which has recently come into use is diethylenetriamine (DETA). This reagent has been the subject of recent research and development efforts in the processing of nickel-copper sulphide ores.In the present study, adsorption trends for DETA have been monitored under the dynamic conditions of flotation using a spectrophotometric method which has been adopted for this purpose at Falconbridge Limited. The results indicate that the adsorption of DETA is quite fast and in the majority of cases, accounts for the disappearance of 75-95 % of this reagent from pulp's liquid phase. The adsorption decreases linearly with an increase in the DET A dosage from 100 git to 600 git. The tailings produced in flotation tests were subjected to washing with deionized water at 60 °C to examine the desorption of DET A. These results indicate that the amount desorbed increases with increasing DETA dosage used during flotation but is less than 7 per cent of that adsorbed. It was found that adsorption of DETA alone, even at relatively high levels, does not always cause depression of pyrrhotite. A new combination of reagents identified in the metallurgical laboratories of Falconbridge Limited utilizes sulphur dioxide with DETA. These reagents together are capable of efficient depression of pyrrhotite on a consistent basis."

Jan 1, 1995

By Collin Bartlett, H. Storch

"Modern metallurgical processes operating with oxygen enriched air, such as the Outotec Flash Smelter and Flash Converter, generate very concentrated SO2 off-gas, which in combination with Outotec sulphuric acid plant technology allows the production of high pressure steam to be used for power generation. Outotec combines well proven technology of sulphur burning plants for this purpose with metallurgical plants.The application of Outotec’s proven LURECTM process enables processing of SO2 gas of up to 25 vol.-%. This process maximizes the energy recovery from the SO2 oxidation at a suitable high temperature level which can be turned into high pressure steam. The application of the Outotec HEROSTM heat recovery system enables the generation of low pressure steam from the absorption energy released at the intermediate absorption step. Additionally, energy is also recovered in the acid coolers for boiler feedwater pre-heating.The concept of integration of high and low pressure steam in combination with the pressurized operation of the boiler feedwater deaerator, thus heating up the boiler feed water to temperatures around 160…170°C, enables indirect transfer of low pressure steam (for deaerator operation) into more valuable high pressure steam, which improves the degree of heat recovery. This is the characteristic of Outotec’s HEROS+TM process.The increased generation of high pressure steam will in turn enable the generation of more electricity when compared to a standard traditional sulphuric acid process."

Jan 1, 2014

By J. Gillies

"Extraction of Gold in Ketone from a suitably prepared sample of sulphide or siliceous ore or concentrate permits a rapid and accurate determination by Atomic Absorption. Mill test products and exploration development samples are acid-treated to effect complete dissolution of silver, copper, zinc, lead, molybdenum and iron present. Interferences in the determination of molybdenum are described. Results by Atomic Absorption are comparable to those afforded by other acceptable methods.INTRODUCTIONDuring recent years much has been written and discussed concerning Atomic Absorption Spectrometry as a technique for determining the concentration of metallic elements. We would, however, recommend a perusal of the paper presented by J. C. Ingles at the annual meeting of Canadian Gold Metallurgists held in Ottawa, January, 1966. The paper was published in the August, 1966, issue of the Canadian Mining Journal, and contains general information on Atomic Absorption.The purpose of our paper is to present certain specific method procedures for the determination of several precious and base metals normally present in Mine, Mill and Smelter products. Of necessity, analytical results should be as accurate as the most suitable available method permits, whether for metallurgical balance, settlement purpose, ore beneficiation programs, or exploration property development. The success of such programs is relative to the accuracy, speed and economics of the analysis. It is obvious, therefore, that in presenting our paper we consider the technique has achieved the desired evaluation."

Jan 1, 1968

By R. R. Potter

"New Brunswick became a separate province in 1784, shortly after the influx of a large number of Loyalists from the United States. Many of these people settled along the Saint John River, including the area of excellent farmland near the present town of Woodstock. There were indications that some of these early settlers recognized iron formations in the vicinity of Woodstock about 1820, however the nature of the deposits was not known until 1836 when Dr. C. T. Jackson, a geologist commissioned by the State of Maine, investigated the mineral potential of the area. Jackson(1) 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 depostis were found in the Nictaux area of Nova Scotia, and a few years later at Londonderry* (Fig. 1). In 1837, Richard Ketchum of Jacksonville, on whose land iron ores had been found, petitioned the provincial government to incorporate a company. After much study, the York and Carleton Mining Company Bill was passed on March 15, 184 7. Several other petitions were passed permitting the company to construct roads, obtain woodland, etc. (2) . The first blast furnace was erected in 1848 on the west bank of the Saint John River near the mouth of Lanes Creek."

Jan 1, 1999