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By D. B. Nazzer

"ANY DISCUSSION of energy today is incomplete without consideration of nuclear energy. In the Maritimes, with plentiful supplies of coal, with relatively easy availabilty of imported oil brought in to the deepwater terminals, with future sources of large supplies of oil and gas anticipated from under our neighbouring continental shelf, and with the Fundy tides, you may question why nuclear energy should be considered. What follows may not give you a specific answer to that question, but it may provide a basis for better understanding. Energy from the sun, from hydraulic sources and from combustion has been available to man from prehistoric times, for thousands of years, but the most sophisticated source of energy, the actual conversion of matter into energy by man, has been developed entirely within the last one-third century, since the discovery of fission in 1939, and the application to generation of electric power has all been done within a generation or less. The pressure of military needs during and after the second world war was largely responsible for the speed of initial development, by funding and focussing the effort needed to develop the basic technology, and in particular materials. The U.S. defence program yielded, for example, the large-scale isotope separation processes for fissile U'35 and for heavy water. The nuclear submarine program yielded zircaloy, a key structural material for the core of the Canadian Candu type reactor."

Jan 1, 1972

By A. Banerjee, J. P. Weiler, J. Jekl, J. T. Wood, R. Berkmortel

"The work presented here is part of an ongoing project designed to develop predictive capabilities of the local mechanical properties, and thus, structural behaviour of a thin-walled high-pressure die-cast AM60B magnesium alloy component. This work focuses on developing correlations between process parameters and local microstructure. Numerical simulations of the die filling and solidification behaviour of the AM60B component were used to estimate local process parameters such as solidification rate, temperature gradient, filling velocity, etc. These estimated parameters were used to establish semiempirical correlations with measured VALUES (of the local microstructure measured in regions throughout the component of different solidification conditions. INTRODUCTIONHigh-pressure die-cast magnesium alloys are experiencing increasing use in structural automotive components. A strength-to-weight ratio comparable to steels and its ease of castability allow for these alloys to be utilized in such capacities as instrument panel beams, seat and door frames, and engine cradles, among others (Gjestland and Westengen, 2007). However, the current use of these alloys is limited due to variations in local mechanical properties. These local property variations restrict part designers to assume lower than actual properties, resulting in larger sections, thus diminishing the light-weighting advantages of magnesium alloys. If these local property variations could be predicted, part designers would be able to optimize die-cast magnesium alloy components and fully take advantage of the light-weighting capacity of these materials.The work presented here is part of an ongoing project aimed at developing predictive capabilities of the local mechanical properties, and bulk mechanical performance, from variations in local microstructure, and ultimately from local process parameters in die-cast magnesium alloys. This project, unique in its nature, is based upon the results determined from fifty sequentially cast AM60B magnesium alloy instrument panel beams provided by Meridian Lightweight Technologies (shown in Figure 1)."

Jan 1, 2012

Introduction A Hypothetical Scenario: Suppose that your company's research department has developed a new device which represents a significant innovation. You would like to begin selling it as soon as possible. The new device has not been publicly disclosed. You're not sure about what type of intellectual property protection you should be seeking, or when you should be seeking it. As discussed below, assuming that the costs are worth it, a patent application probably should be filed before any public disclosure is made. In general, if you do not file a patent application prior to a public disclosure, you will lose rights. Major Types of Intellectual Property In this paper, intellectual property protection is broadly discussed. Practical steps which can be taken to minimize the possibility of losing intellectual property rights (and maximizing the possibility of benefiting from your company's intellectual property) are outlined at the end of this paper. The issues discussed in this paper are somewhat complex, because a number of outcomes are possible, depending on the facts. It is strongly recommended that you seek legal advice in your jurisdiction in connection with any particular circumstances relating to intellectual property rights. "Intellectual property" refers to a number of different types of rights. The major types of intellectual property are: (i) patents; (ii) trademarks; and (iii) copyright. Trade secrets are also usually considered to be a type of intellectual property, and they are also discussed in this paper because of their importance. In general, each of these types of intellectual property protects different subject matter, although there can be some overlap. Intellectual property rights are generally territorial in nature. The scope of protection of a type of intellectual property in a country (e.g., patent protection) depends on whether the specific national requirements for protection have been met.

Feb 1, 2008

By Bruce W. Smith

Non-contacting, radioisotope density and level gauges are discussed. The characteristics of the more commonly used isotopes, the techniques of detection and the methods of presenting information are reviewed. The gauge parameters of accuracy, response time and long-term stability are tabulated with reference to calibration techniques and operating requirements. Automatic control systems, both pneumatic and electrical, are used in conjunction with density gauges on filter feeds, and in thickener underflow and heavy media processes. These systems are described. Procedures for installation, start-up and operator training are outlined, along with considerations of preventative maintenance and service requirements. Typical gauge system costs, including capital expenditure, installation, start-up and service, are presented, wherever possible, in order to provide a basis of comparison with more conventional systems.

Jan 1, 1964

By A. McLean, Q. R. Yang, Y. D. Yang, G. F. Zhang, P. Wu

A considerable amount of waste slag from the pyrite roasting process is discharged every year. Recovery of iron from the waste slag is of great interest for comprehensive use of mineral resource, reduction of environment impact and improvement of economical benefit to related companies. The objectives of the present work are focused on: (1) Compare various procedures for recovery of iron from the waste slag and select a best procedure for industrial trial which is roasting of the waste slag under reducing condition followed by magnetic separation; (2) Investigate the optimum conditions for maximum recovery of iron from the waste slag. The experimental result shows that under the treatment condition found in this work about 36 to 40% of the iron oxide was recovered from the waste slag, where the iron content in the concentrate is 57%. The total recovery ratio of iron, up to 70%, from the waste slag was achieved. After the treatment, sulphur content in the waste slag was reduced significantly and gangue materials, such as SiO2, Al2O3 and TiO2, were reduced effectively.

Jan 1, 2011

By F. R. Erick Mulder

"AbstractTwo bottom-hole samples have been taken from two new completions in the Turner Valley field, Royalite Lowery No. 8 on the west flank and Royalite No. 73, which was deepened into a lower fault block, on the northeast flank. From the bottom-hole oil of Royalite Lowary No. 8 a synthetic sample was prepared to simulate the original fluid in the reservoir, saturated at the gas-oil contact conditions. The sample from Royalite Lewery No. 8 has been shown to be the original fluid present at this well and represents the oil phase near the oil-water contact in• the reservoir. Complete chemical analysis, P.V.T., and viscosity data have been obtained on these reservoir fluids, which represent the range of saturation from the gas-oil to the oil-water contact in the Turner Valley oil structures. Sampling techniques and the application of the analytical data to reservoir conditions and field operations are discussed. Super-compressibility curves for an average separator tail gas have also been prepared. These data have not been available before. They will be of fundamental value in futu.re reservoir engineering studies of this field and will also serve as a guide in determining operating practices."

Jan 1, 1950

By L. Drisdelle, S. Gendron

"Survival in today's business climate requires participation of all employees in a Total Quality Management Program encompassing everything - ""safety, quality of products, quality ofet1ch and every job done, and of course production "". We all know what needs to be accomplished, but struggle with how to do it, especially in an industry which has not always experienced management/union cooperation, and mistrust is still present.This paper describes a process to improve team work and employee involvement in Inco's nickel carbonyl refinery at Copper Cliff The process involves facilitatorship training for all employees, and a system for reinforcing and accomplishing the required behavioural change. The system is described in detail and a number of examples are presented. At the refinery, the staff is starting to understand as Max DePree recently wrote ""Without Quality Behaviour, you cannot have Quality Product"". IntroductionThe Copper Cliff Nickel Refinery (CCNR) is Inco's largest and most modern nickel refinery, which celebrated its twentieth year of successful operation in April 1993.The heart of the refinery is the Inco pressure carbonyl (IPq plant which produces high purity nickel pellets and specialty powders by refining an approximate 80% nickel granule feed. The carbonyl plant is a modem chemical plant with very special and demanding requirements for safety and environmental protection due to the toxic nature of the refining gas.Since 1987, there has been an emphasis at CCNR on a comprehensive Total Quality Improvement (TQI) Program which was designed based on recognizing customers' needs for improved systems for quality management. This program is customer oriented and comprises such elements as team organizational concepts, customer audits, process assessment and internal quality auditing.A detailed review of progress was made in early 1991 and it became apparent that the ""ownership"" of the TQI program was not broad based. In fact, the program was very much a staff driven effort and fell far short of total employee involvement and relentless continuous improvement that are now considered essential to remain competitive and stay in business.Inco staff has now come to regard that early phase of our TQI program as ""the technical aspects of total quality improvement"".The safety experience was also puzzling. Even though the safety statistics were good with an average lost time frequency of 1.6 for the last five years, the perfonnance improvement had plateaued and remained pretty much the same. Clearly a new approach was required if significant progress and continuous improvement was to be made."

Jan 1, 1994

By Yu Chen, Charlie C. Li

The application of rock bolts for the stabilisation of underground openings needs a good understanding of the response of the bolts during rock excavation. The pull-and-shear performance of two types of rock bolts—that is, the fully encapsulated rebar and the D-Bolt—has been studied both experimentally and numerically. The rock bolts were tested under a pull-and-shear load at five displacing angles (i.e., 0°, 20°, 40°, 60°, and 90°), and at the same time, the strains on the bolts were monitored during testing. The two types of rock bolts have similar loading capacities, while the loading angle has obvious influence on the deformation capacity of the D-Bolt. The ultimate total displacement of the D-Bolt decreases from 140 mm under pure pull loading to 70 mm under shearing. The displacement capacity of the rebar is not significantly influenced by the loading angle but remains at a quite low level from 29 to 53 mm. The D-Bolt yielded in a longer section the rebar bolt under pure shear. A trilinear material model was used to simulate the strain hardening behaviour of the bolt steels in the numerical code FLAC3D. The numerical results show that the axial load in the bolt decreases exponentially with the distance from the loading position for the rebar bolts, but it remains constant in the bolt sections between the anchor positions for the D-Bolts. When the bolt is subjected to a lateral load, shear stresses are created on the D-Bolt surface within a short distance from the loading position.

Jan 1, 2015

By C. Andrews

Fuel cell testing requires fully automated operation, on-site configuration of tests, and real-time monitoring for performance and failures. Balancing the flexibility and programmability of a test station with reliability, cost, and user interface can be a daunting challenge to the test equipment engineer. Endurance testing of fuel cells requires the highest level of reliability for test stand hardware and software without compromising automation capabilities or users interface. Techniques for implementing an ultra-reliable test platform addressing hardware limitations, sophisticated watchdog monitoring to prevent inadvertent shutdowns, and software limitations (e.g., balancing a highly-functional graphical users interface with reliability) are presented.

Jan 1, 2005

By Sunil S. Gandhi

"The Mountain Lake deposit is a tabular sandstone-type uranium deposit, hosted by the basal unit of Middle Proterozoic Dismal Lakes Group. Uranium occurs mainly as sooty pitchblende disseminated in stratiform lenses within gently dipping quartzose sandstone. It is associated with copper sulphides, pyrite, hematite, and traces of nickel and cobalt arsenides and of silver.Exploration HistoryUranium showings on the PEC claim group were discovered during 1969 by an airborne radiometric survey carried out over the Dismal Lakes-Great Bear Lake area by Aquitaine of Canada Limited (Bizard and Salat, 1969). Some drilling was done in the vicinity of the showings in 1975 by the company under a joint venture with Eldorado Nuclear Limited but the results were not encouraging (Hassard and Woollett, 1975). During 1972, Trigg, Woollett and Associates Limited conducting surveys for Imperial Oil Limited, discovered numerous high-grade radioactive boulders scattered over a distance of several kilometres north and west of the showings, and the area north of the PEC claims was staked as the YUK claims (Ahuja, 1974). A systematic study of the boulder distribution and Pleistocene geology suggested a source additional to the showings. More intensive exploration followed, and in 1976 drilling just north of the PEC claim group boundary intersected the main deposit at a depth of 75 m to 150 m, beneath overburden up to 60 m thick. Part of the deposit extends into the PEC claim group which is under exploration by the Aquitaine-Cominco Joint Venture.The following brief description is based on the presentations in 1978 by F. Hassard of Trigg, Woollett and Associates Limited at the Geoscience Forum in Yellowknife, and by S.S. Gandhi of the Geological Survey of Canada at the Mineralogical Association of Canada Uranium Short Course in Toronto."

Jan 1, 1986

By A. Garnier, K. Tremblay-Bouliane, B. Gaillet, S. Moineau, D. Tremblay

"A heptapeptide library displayed on M13 bacteriophages (phages) was screened to identify peptide sequences able to selectively bind to gold, chalcopyrite, sphalerite, pyrite, and silica ores, and to evaluate phage potential as bioflotation reagents. Many peptide sequences were isolated through biopanning and differed from known sequences. Adsorption isotherms were determined and a receptor/ligand interaction model was identified and used to compare affinity of peptide sequences toward ores. Some phage sequences have slightly lower affinity to sphalerite than other sulphides. Adsorption was higher on sulphides than on silica. Induction time measurements suggested filamentous M13 phages lower hydrophobicity of the ore surface.RÉSUMÉ Une librairie d’heptapeptides présentés sur des bactériophages M13 (phages) a été criblée afin d’identifier les séquences peptidiques affinitaires à des minerais d’or, de chalcopyrite, de sphalérite, de pyrite et de silice et d’évaluer le potentiel de ces phages en tant que de bio-réactifs de flottation. De nombreuses séquences peptidiques ont été isolées par bio-criblage et différenciées d’autres séquences connues. Des isothermes d’adsorption ont été déterminées et un modèle d’interaction récepteur–ligand a été identifié et utilisé pour comparer l’affinité des séquences peptidiques par rapport aux minerais. Certaines séquences de phages possèdent une affinité légèrement inférieure pour la sphalérite comparativement aux autres sulfures. L’adsorption sur les sulfures était plus élevée que sur la silice. Des mesures de temps d’induction suggèrent que les phages filamenteux M13 diminuent l’hydrophobicité de la surface des minerais."

Jan 1, 2016

By John C. Luck Jr.

"DEVELOPMENT of oil emulsion mud dates back to the early days of rotary drilling when oil was added to the drilling mud solely for the purpose of freeing stuck drill pipe. After the drill pipe was freed, and drilling resumed, this oil was considered a contaminant. Efforts were made to remove the oil but some of it remained and was emulsified with the drilling mud, thus forming a mechanical emulsion.During the late 1930's, operators found that adding crude oil to drilling muds seemed to alleviate 'sticky-hole' problems and so oil was allowed to remain in the mud. This practice was adopted when it was found that faster drilling rates and longer bit life were obtained. These observations led to the development of emulsion drilling muds. During the past five years their application has become more widespread because of the lower fluid losses obtained, greater lubrication qualities, faster penetration rates, and generally better hole conditions.An emulsion may be defined as a two-phase system consisting of a mixture of either finely divided oil droplets in water or of finely divided water droplets in oil. The surrounding liquid is known as the continuous phase. The emulsifiers reduce the interfacial tension, making the droplets tend to repel each other so that they remain dispersed and stabilized. These emulsions are classified as oil-in-water or as water-in-oil, depending upon whether water or oil, respectively, is the continuous phase. Briefly, close inspection shows that they consist essentially of globules of• the one liquid suspended in a continuous mass of the other liquid. Oil emulsion muds are usually of the oil-in-water type. Two basic types of emulsifiers •commonly used in Canadian muds are soaps and lignites."

Jan 1, 1954

By A. P. LeBis

This article attempts to relate the concept of utility to the risk involved when only a small number of projects (compared to their probability of occurrence) are accessible to a firm and to quantify utility when other financial and physical parameters are known.

Jan 1, 1978

By P. Nelson

Extending the campaign life of the Mitsubishi furnaces at Xstrata Copper's Kidd Metallurgical Division Copper Smelter has been a major focus of attention for many years. One aspect of this effort is real time monitoring to detect abnormal conditions and safely shut the furnaces down before significant damage occurs. Traditional real time methods of monitoring the integrity of refractory furnaces containing molten metal include alarms on individual temperatures of the refractory or cooling water. The need to set alarm limits which are not exceeded across the range of normal operating conditions leads to a system that only provides a limited warning, if any, before a failure occurs. Integrity monitoring systems that look at many different signals and alarm only changes in the relationships between the signals have been implemented on the smelting and converting furnaces. The systems are based on principle components analysis (PCA) models and implemented with the monitorMV software package. These provide much more sensitive and selective alarms so that changes in integrity are alarmed well in advance of any event. At a critical alarm level, the converting furnace is set to automatically shut down so that operating and technical personnel can review the situation. The configuration of the systems and operating experience with them will be discussed.

Jan 1, 2007

By Par G. Jönsson, Joachim von Scheele, D. S. Sarma, Mukul Goyal

Dust from flue gas cleaning systems at iron and steel production is frequently considered as a waste problem, but it is actually a potential raw material source. By using a technology like the oxyfuel based OXYFINES technique, it can be melted into a suitable form. The product from this processing, however, needs to meet the requirements of a recyclable raw material, here particularly a top-charged blast furnace feed. The present work has been focused on characterization of the product produced from these dusts by OXYFINES technology. The investigation has been carried out on samples of processed dusts from a European integrated steel mill. It was done by means of chemical analysis, density measurement, light optical microscopy, X-ray diffraction, scanning electron microscopy combined with energy dispersive spectroscopy, and micro indention hardness measurement. Special attention was paid to the presence of zinc, an element that might be harmful while recycling the material (e.g., in a blast furnace). The results show that the product contains four different regions with different morphologies and properties in the material, which are discussed in detail. The overall conclusion is that by processing the dusts in this way, a raw material suitable for recycling in a blast furnace can be obtained.

Jan 1, 2004

By Roberto Pena, Cristhian Morales, Darwin Morales, Veronica Cambiaso

"This article makes evident the shortcomings of the current operation of oxygen pipes as well as the damages they cause and why they cause them. When focusing on the causes and effects of these drawbacks, it was possible to develop a new family of thermal lances that could pierce a taphole with the precision of a drill but with the capacity to complete the whole operation. Although efforts have been made to replace oxygen pipes since they are annoying, dangerous and inefficient, nobody had worked to improve the way the traditional oxygen pipe taps/perforates the furnaces and reactors tapholes. In fact, developments made in drills and robotic arms, have failed to replace the oxygen pipe, which despite their negative side effects have been used for more than a century. Observation and theory were key to radically transform this humble tool into a dependable and efficient support in the operation. A good news that it is worthwhile to share for the benefit of all of us, passionate about the world of pyro metallurgy.INTRODUCTION Normally, reports and papers prepared for conventions, symposia or other technical events related to metallurgy aim to relevant topics in the operational field, probably because in them lay the scale economies every company pursues. We intend to give relevance to a matter normally disregarded in operations, but that unmistakably vital: if the furnace or reactor cannot be bled, the pyrometallurgical process will not be completed. Besides, if the tapping task is difficult or is long delayed, the availability of the furnace will be reduced. Consequently, there will be a waste of energy and workers will be exposed to dangerous levels of radiation as well as to work overload and physical injuries Apart from these basic effects, in tapping operations where oxygen pipes are used, we can see serious damages in the smelting furnace, especially in the taphole components such as refractory bricks, taphole jackets and water cooled plates. This paper intends to show that taking care of the tapping task can significantly upgrade not only to the tapping operation itself, but also the whole plant productivity."

Jan 1, 2017

By J. M. Wolverton

CONSIDERABLE interest has always been taken in Safety-First and First Aid at the Sullivan mine. Even during the early days of development, Safety-First committees periodically held meetings, while lectures in first aid were given to any employees interested in the work. In 1929, a Safety Department was organized, and all accident-prevention and first-aid work was put in charge of a full-time Safety Engineer. An extensive programme has gradually been developed, the value of which can best be indicated by the reduction of the accident rate from 18.4 shifts lost per 1,000 shifts worked for non-fatal accidents and two fatalities for 1927, to 3.24 shifts lost per 1,000 shifts worked and no fatalities for 1936. SUPERVISION All work connected with accident prevention or first aid is under the jurisdiction of a central committee, known as the Accident Prevention Committee, which meets regularly once a month. It consists of all superintendents, department heads, foremen, and shift bosses, and is presided over by the Safety Engineer. At these meetings, the accident records of the previous month are reviewed and all accidents carefully analyzed and discussed. All proposed changes in the safety rules or in the accident tprevention programme are taken up and passed upon. Complaints or suggestions from the Safety-First Committee and the Employees Co-operative Committee, dealing with safety, are discussed and passed upon or a subcommittee is appointed to investigate and take any action found advisable. The question of underground ventilation and dust control, which recently has become a very important problem, always receives considerable attention.

Jan 1, 1937

By L. H. Chen, Y. C. Chen, Leo Benyamin, W. C. Chen

"To investigate the evolution of fluid-driven fracture of rock-like material subjected to borehole fluid pressure and its consequential damage with regard to post-peak stabilization, micro-seismic activities have been monitored using nondestructive technique of acoustic emission (AE) corresponding to the macro-scale complete history of loading curve by setting the hollow cylindrical external circumferential strain to be a closed-loop feedback signal during servo-fluid-driven tests. Development of a novel fluidinduced loading system injected from internal borehole as well as monitoring system were equipped such that the initiation and propagation of micro-cracks enable to analyze experimentally. By programming/controlling either injection rate or fluid pressure, synthetic sandstones with low-permeability made by cement mortar were conducted in this study. It found that both the growth of macro-crack initialized intensively as reaching the breakdown pressure and the micro-seismic activities represented by AE locations show nice agreement. The experimental results in this paper provide better understandings of fluid-driven fracture mechanism.INTRODUCTIONFluid-driven fracture is a process of generating cracks by injecting viscous fluid into solid material. Conventionally, fluid-driven fracture tests have been performed by mining industry to measure the in situ stress (Haimson & Fairhurst, 1969) and fluid-driven fracture has been employed by the petroleum industry to recover oil and gas. Additionally, the mechanism of crack growth or the extension of existing cracks is important to the evolution of volcanic dikes over distances of a few kilometers (Lister & Kerr, 1991; Rubin, 1995), crack propagation in dams (Bolzon & Cocchetti, 2003) and the disposal of radioactive waste (Sun, 1969)."

Jan 1, 2015

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 T. W. Cavers

The Dwight-Lloyd sintering machine was the answer to the flue-dust problem of the copper blast-furnace smelter. Then came concentration by flotation, which threatened to eliminate the blast furnace from the smelting field altogether, and again the sintering process solved the problem. As is well known, the sintering process is dual in its function; it expels sulphur from the charge and it converts a powdery material into nodules or chunks that hold together. The charge is ignited on top just as it passes over the edge of the first suction box, and the oxygen of the air that is drawn downward through the charge breaks up the sulphide and oxidizes about fifty percent of the sulphur. The heat produced by this reaction in the upper stratum of the charge ignites that lying immediately below, and, when the pallett has travelled the full length of the machine, the tire has reached the graces and the fine concentrate has changed its characteristics by being partially fused and has become a more or less solid mass. When the Granby Company was smelting its ore as mined, one small D-L machine was adequate for the treatment of the flue dust, but as soon as the policy of smelting the concentrate was adopted, it became necessary to add two large machines to the sintering plant. The three sintering units, of which two are 42 in. by 396 in. and the other 42 in . by 264 in. in hearth area, have a combined capacity of from 370 to 450 tons (dry) of charge per day. The capacity varies directly as the hearth area. The sinter produced is about 88 per cent of the dry charge, or 325 to 400 tons per day. The sintered fines returned for resintering average between 30 and 35 per cent of the charge, but this is not as great a disadvantage as might appear, since the addition of hot fines improves the burning qualities of the mixture. From 50 to 54 per cent of the sulphur is eliminated in the sintering operation.

Jan 1, 1934