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By F. T. Rabbitts

Introduction When the investigation of radioactive ores began at the Mines Branch about five years ago it was at once evident that improved chemical methods for the determination of uranium were essential. The published methods available were time-consuming and insensitive and were lacking in accuracy and precision. It was desirable to obtain methods which would be rapid, sensitive, and accurate. They should also allow for the possible presence of any interfering elements and should be adaptable to routine analysis by technicians. Chemical methods are necessary to provide standard analysed samples for counting and to check analyses by counter methods. Moreover, counter methods cannot be used, and only chemical methods are suitable, when the sample is not in equilibrium, as with weathered minerals and leach residues. As leaching processes are improved, more sensitive chemical methods are required for the increasingly lower content of uranium in the leached residues. When the leaching process reaches the plant stage, speed of analysis becomes more important, without sacrificing accuracy. The purpose of this paper is to describe briefly .the methods used at the Mines Branch for the chemical analysis of uranium in ores. These methods represent the results of investigations by a number of groups in the United Kingdom, the United States, and Canada.

Jan 1, 1952

By J. Fixter, P. Prangnell, Z. Pinter, E. Eimer, B. Chehab

"High deposition rate Wire and Arc Additive Manufacture (WAAM) can provide benefits to the aerospace industry, including a reduction in lead time, reduced material waste and, through higher solidification rates, refinement of the as-built microstructure relative to a cast material. However, candidate 2xxx series high strength alloys for this process normally require a solution treatment, which is problematic for large near-net-shape components, and age hardening to achieve maximum mechanical properties. With each layer being subject to multiple thermal cycles, exploiting the thermal conditions in the WAAM process to avoid post-build solution treatment is therefore of interest. A solutionisation model has been developed for the WAAM process, based on diffusion controlled dissolution using DICTRA, which was validated through thermal simulations combined with 2D and 3D image analysis. The model has subsequently been used to simulate the solutionisation behavior during a typical WAAM thermal cycle and to explore what could theoretically be achieved by, for example, refining the starting microstructure.INTRODUCTION There is currently great interest in exploiting additive manufacturing (AM) in the aerospace sector due to several benefits it can potentially provide; including reduced material waste, shorter product lead times and greater design freedom (Herzog, Seyda, Wycisk, & Emmelmann, 2016). However, with aluminium alloys the material properties obtained are generally inferior to those of conventional high-strength wrought products; therefore more research is required to explore the potential for exploiting the unique process conditions in AM to improve the as-deposited microstructure. A range of AM techniques are now available (Debroy et al., 2018), which differ in terms of the feedstock type and power source and it is necessary to match the appropriate technology to a particular application. This generally requires a compromise between the build rate and shape resolution. Wire and plasma-arc additive manufacturing involves using an electric arc to melt wire onto a substrate, and fabricates a part by building up overlapping layers of deposited weld beads (Addison et al., 2015; Williams et al., 2015). The benefits of this process over other AM methods are the much higher deposition rates (e.g. kg’s/hour) achievable and lower capital equipment costs relative to powder bed techniques, which makes it suitable for large scale applications. However, limitations include a lower part complexity, lower solidification rates and a greater need for post-process machining (Frazier, 2014)."

Jan 1, 2018

By T. M. Ahmed

Sherritt International Corporation experienced corrosion failures with the 316L stainless steel tubing in a high-pressure still condenser employed for ammonia recovery. A detailed failure analysis was conducted on the condenser tubing to determine the mode and the root cause of the failure. The analysis included both optical and scanning electron microscopy (SEM) of the inner and outer surfaces of the tube as well as characterization of the corrosion products using energy-dispersive X-ray spectroscopy (EDX). Results revealed that the corrosion attack was confined to the first ?100 mm of the tubing at the inlet where the tube was connected to the top tubesheet. The tube suffered both external stress-corrosion cracking (SCC) and crevice corrosion from the shell side (water side), and wall thinning of the inner surface (the tube side) due to erosion corrosion. It was evident that failure of one of the tubes occurred due to SCC that penetrated the whole wall thickness and resulted in a leak failure. Some prevention measures are proposed to avoid this type of corrosion attack in the future.

Jan 1, 2005

By C. H. Hopper

DIAMOND drills have played an important part in the development of mines for many years. Recently. they have also entered the production field arid the use of diamond drills m the primary breaking of ores has become a big branch of the industry. The writer has estimated roughly that the total diamond drilling in Canada during 1942 was 5,625,000 feet, of which 2,250,000 feet, or 40 per cent, was for blast-holes. This accounts for 6,750,000 tons of ore broken, using the conservative factor of 3 tons per foot of hole. Many consider that the use of diamond drills for blast-holes is the most important advance in mine practice of the past decade, and the industry owes a great deal to the staff of Noranda Mines, Limited, for the pioneering they have done in the development of long-hole mining methods and for publishing their results. A great many mines have followed Noranda's lead. At the Waite-Amulet, Aldermac, Flin Flon, Canadian Malartic, Hoyle, and Matachewan Consolidated mines, most of the ore is broken by long-hole blasting. While the mines were developing new methods, the diamond-drill industry was developing mechanically-set bits and better machines. Through the effective use o smaller, cheaper diamonds, as well as more efficient setting, bit costs per foot are only one-half what they were ten years ago. Few people realize that a diamond bit is relatively inexpensive. The common EXT coring bit, for example, contains some 200 small diamonds, weighing altogether about 2.70 carats which, at $3.40 per carat, cost $9.20. After use, the equivalent of about 100 of these diamonds may be recovered. Therefore the true cost of the bit is only $7.00, made up of $4.60, the cost of the diamonds lost, $2.00 for setting, and $0.40 tax. The trend in machines has been toward specialization for the different classes of rock in blast-hole work. Light, high-speed machines have been developed for soft ores and higher powered machines for hard ores.

Jan 1, 1943

By James D. Hall

THE Dome ore-bodies are more or less isolated and are mined. by shrinkage stoping. An interwoven system of veins is mined at Hollinger '.1.nd requires close filling. Deep mining is the problem at McIntyre. Dome ore contains a large amount of free gold, which is recovered on blankets. An all-cyanide flow-sheet is \lSed in the Hollinger mill. Flotation concentration is an important feature of McIntyre mill operation. Therefore, these three mines afford an unusual opportunity to compare gold mining and milling methods. The purpose of this paper is to describe the conditions existing at the Dome, Hollinger, and McIntyre mines and to outline the mining and milling practice at each property. Figures 3, 4, 5, and 7 are reproduced from the Canadian Mining ]011rna/, September, 1935 (Young, A. W., Mining at Hollinger), and Figures 8 to 11 from the Engineering and Mining Journal, November, 1933 (Keeley, D. E., Development and Mining at McIntyre). The photographs (Figures 6, 12, and 13) are by The Canadian Government Motion Picture Bureau. Diagrams of the several mill flow-sheets, which formed a part of the original paper, are not reproduced here. They will be found in Dorr's Cyanidation and Concentration of Gold and Silver Ores.

Jan 1, 1938

By Raymond B. Hryciuk

Environmental auditing has evolved rapidly over the last decade — first in North America, then Europe, and most recently in Asia — into a widely practiced discipline designed to provide senior management with assurance that operations are being managed in compliance with established governmental standards, internal company policies, and good industry practices. This paper first examines the evolution of environmental auditing, focusing in particular on three interlocking driving forces: company initiatives, collaborative industry initiatives, and government initiatives. Characteristics of effective audit programs, those that have emerged among the leaders, are discussed, including: objectives, scope, coverage, approach, staffing, and organizational considerations. The author then addresses important future trends and developments for environmental audit program design, content, and coverage.

Jan 1, 1996

By A. I. Collins, D. Danninger

Newmont has installed advanced control and online optimization on the dry grinding circuit and both roasters on its Carlin Trend refractory ore treatment plant. Subsequently, Newmont has developed a master plan for institutionalizing advanced control and optimization on all its processing units. Newmont is committed to a program of applying advanced control and optimization from crushing of ore to pouring of gold. This paper describes Newmont's experience with implementing advanced control and optimization and the benefits received. In addition, identification of advanced control and optimization opportunities and their economic justification is discussed.

Jan 1, 2005

By G. A. Bezuidenhout, J. Davis, S. Lefume, J. P. T. Kapusta, D. K. Chibwe

"Although the centennial of the Peirce-Smith (PS) converting process has recently been celebrated, the technology has essentially not changed much since its inception. PS converting is used extensively in the Cu, Ni and PGM industry to remove iron and sulphur from a molten matte phase. A typical PS converting process would use low pressure air supplied by a blower to bubble air through the molten bath. This bubbling injection regime is inherently inefficient from a process and energy consideration. In the late 70’s and early 80’s, Brimacombe and co-workers demonstrated at both laboratory and plant scales that sonic injection (jetting regime) into copper or nickel converters could reduce or eliminate the above hindrances characteristic of PS converting. Since then, in spite of these successes, very little industrial applications have made headway in the converting process of non-ferrous metal mattes on a commercial scale. As part of its operational improvement and energy reduction program (process efficiency), Lonmin Platinum decided to conduct a full scale industrial evaluation of sonic injection using air only to establish if punchless, high efficiency sonic injection was feasible in its small 3.05 × 4.57 m converters (10’ × 15’). A plant trial was run for four weeks in one of its three converters. This paper discusses the plant demonstration with a focus on the experience acquired by Lonmin together with the key learnings from the trials. Reference will also be made to the commercial aspects of a full scale implementation of sonic injection in all three converters in the smelter. INTRODUCTION AND OBJECTIVESAlthough the centennial of the Peirce-Smith (PS) converting process has recently been celebrated (Peirce and Smith, 1909; Southwick, 2009), the technology has essentially not changed much since its inception. PS converting is used extensively in the Cu, Ni and PGM industry to remove iron and sulphur from a molten matte phase. A typical PS converting process would use low pressure air supplied by a blower to bubble air through the molten bath. This bubbling injection regime is inherently inefficient from a process and energy consideration."

Jan 1, 2012

By T. Holmes, S. Davison

"The Special Standard Surge bin at Agrium’s Vanscoy Potash Operations (VPO) has been plagued with flow problems and wear, and corrosion issues for it’s entire working life. Investigation showed that the carbon steel construction, bin geometry, and resultant funnel-flow pattern were directly responsible for production losses and disproportionate maintenance and capital costs. Potash enters this bin at between 140°C and 165°C, but the stagnant potash outside the active flow channel was much cooler, allowing moisture to migrate toward the outer regions, which caused corrosion of the walls and reduced live capacity as the potash in this area hardened and built up on the walls over time.A 2013 inspection revealed holes and paper-thin areas in the lower cylinder wall sections and in the conical hopper. The only thing preventing major leaks and even a potentially catastrophic failure was the buildup of stagnant hardened product on the cone walls. It was concluded that the cone had reached the end of its life and required replacement. VPO’s original plan was to replace the cone in kind and repair the cylinder as necessary; however, a failure-mode and bin-performance investigation combined with a lifecycle- cost analysis indicated it would be better to redesign the hopper.For success in retrofit projects, it is essential at the design stage to consider the bulk solid flow properties and the operating environment involved. Because education in this area is not offered at a university level, engineers often do not fully appreciate the effects of the flow properties of bulk solids on bulk material handling equipment.Jenike & Johanson conducted flow properties tests on samples of potash and using the data, redesigned the bin and the feeder. After the modifications, VPO’s surge bin provides safer, more reliable operation with a much longer predicted working life. Using this retrofit as an example, we aim to provide a general understanding of bulk solids flow theory and highlight the importance of customizing the design to the appropriate flow properties in the cost effectiveness, reliability, and safety of a bulk material handling system."

Jan 1, 2016

By M. F. Goudge

MAGNESIA refractories and magnesium metal are both essential war commodities. The need for magnesium, which had just made its debut as a commercial metal a few years before the outbreak of the present war, is widely known because this new and valuable light metal has already received much publicity. Less widely known but equally important in the war effort are magnesia refractories. They are indispensable to the efficient functioning of the great metallurgical plants producing steel, nickel, copper, and other metals, where, because of their resistance to extreme high temperature and chemical attack, they are used in lining the furnaces, which are operated at a white heat. The demand for refractories in the metallurgical industries rose rapidly upon the outbreak of war, and now, in consequence of the continued great expansion under way in the manufacture of steel, nickel, copper, and other metals, the need for magnesia is greater than ever. Since 1915, part of the Canadian requirements of basic refractories has been supplied from the deposits of magnesitic dolomite in Argenteuil county, Quebec. The products from these deposits are excellent for many uses, but the magnesitic dolomite has too high a content of silica and lime to be used in making a type of magnesia brick required in nickel converters, and in the roofs of reverberatory furnaces used in the copper and steel industries. There is now a large and growing demand in Canada for bricks and shapes for these uses. This demand has always been supplied from the United States. Makers of these products in the United States, in turn, formerly imported most of the necessary high-grade, dead-burned magnesia from Austria and Manchuria. Not only are these sources closed, but refractory chrome ore from the Philippines is no longer available and chrome refractories may have to be in large part replaced by magnesia.

Jan 1, 1942

The recovery of fine hydrophilic gangue in flotation is related to the recovery of water. Water is carried by bubbles as a film and wake into the froth. The amount carried (entrained) depends on bubble size, gas rate and the subject of this paper, frother type. To isolate the effect of frother type from that of bubble size and gas rate, gas holdup is used as the correlating variable. Measurements were made using a bubble column (no solids) operated continuously with the overflow recycled. Continuous operation meant some foam depth was required to ensure only entrained water is recovered. Using an automatically controlled 7cm foam depth the overflow rate of water is used as a measure of 'water carrying rate'. It is shown that the common frothers can be grouped into four families based on the water carrying rate-gas holdup relationship.

Jan 1, 2006

By S. W. Marcuson, P. J. Mackey

The 1973 Oil Embargo and succeeding disruptions in supply had a profound effect on energy costs and consumption patterns in the developed world. This was especially true in the USA where post World War II growth, fueled by low-cost imported oil, left the country dependent on uninterrupted oil shipments from the volatile Middle East. In this atmosphere, Professor H.H. Kellogg of Columbia University, convinced of the necessity of good environmental stewardship by the writings of the era’s leading environmentalists, developed a methodology for evaluating energy and process efficiency of metallurgical processes and wrote a series of papers describing and applying the techniques. One of these, "Energy Use in Sulfide Smelting of Copper" is recognized as a seminal work which both described the state of energy usage in copper smelting in the mid-1970’s and portended future developments. The background to these papers is examined and the current and past Cu-Ni matte smelting practices in Canada are examined in the context of the results. Data from early 20th century publications describing reverberatory and blast furnace operation is employed to show that energy consumption for much of the century was several multiples higher than that calculated for best reverberatory operation in the 1970’s.

Jan 1, 2015

By D. Krippner, C. Nexhip, D. George-Kennedy, P. Gebski, R. Kaur, W. L. Ying

ABSTRACT Water-Cooled Tapblocks Are Essential Components Of Modern Smelting Furnaces. Uninterrupted Operation Of A Tapblock Is Critical For The Optimal Operation Of A Furnace. This Critical Function, Together With Exposure To Extreme Conditions, Drives The Need For An Efficient And Reliable Means For Tapblock Monitoring. The Main Objective Of Tapblock Monitoring Is To Help Optimize The Life Of The Tapblocks By Better Scheduling Inner Refractory Relining And Protecting Operators By Preventing Sudden Deterioration Of The Tapblock. A Taphole Acoustic Monitoring (TAM) System Was Developed To Meet The Above Requirements. This Paper Describes The Principles Of The TAM System And Selected Case Studies.

Jan 1, 2013

By Q. G. Reynolds, R. T. Jones

The choice of furnace design parameters has a marked effect on the integrity of the furnace that is constructed. The design methodology for DC arc furnaces typically begins with the chemical reactions and feed materials that define the process. The specific energy requirement of the process, and the feedrates of the raw materials largely determine the power requirement for the furnace. A chosen value for the 'power intensity' sets the diameter of the furnace. Justification is provided for why this is a good choice of scale-up parameter. Equations are presented to quantify the resulting trade-off between thermal efficiency and the degree of error that can be tolerated in the balance between power and feedrate. This improved understanding should provide a better rationale for selecting an appropriate power intensity (or furnace diameter) for future furnaces.

Jan 1, 2015

By S. A. Pence, A. I. McCallum, V. de Korompay

"Special salt protection rings containing a water-swell• able, polymeric sealant are in successful operation in Canadian potash shafts. Installed above the Prairie Evaporite salt formation at a depth of 3,000 feet, the sealant is preventing formation water migration into the salt and pressure build-up on the concrete lining of both production and service shafts. The salt protection rings are not under the hydrostatic pressure of the formation water.The chemical sealant in use has the unique property of imbibing water and swelling. •Therefore, any water at• tempting to flow by the seal ring actually produces a tighter seal.The purpose of this paper is to discuss the sealant and its properties and uses. Installation of the material and its operation in two Canadian mine shafts is described."

Jan 1, 1971

By V. Gregoire

THE DEVELOPMENT by the Iron Ore Company of Canada of the Quebec-Labrador mining project, which eventually led to 'Iron Ore in 1954', involved, from the start, several distinct undertakings. Among them, the most important were: The construction of a 360-mile railway, linking Knob Lake with Seven Islands. The erection of a railway terminal, and harbour facilities, at Seven Islands itself. The building of an entire townsite at Schefferville (formerly Knob Lake) The construction of two hydroelectric plants; and, finally, The development of a sufficient number of orebodies to enable a production of 10 to 15 million tons of ore a year. Since these phases of the project have already been the subject of previous discussions, this paper will not elaborate further on them but will rather concern itself with a brief outline of the Company's current mining practices.

Jan 1, 1958

By M. Pfeifer, M. N. Brodie, D. J. Barratt

"This paper reviews design trends related to the various SAG mill configuration and drive options available today. The impact of these options on capital and operating costs is assessed, and key technical issues reviewed. The discussion is based on the conventional North American ’pancake’ mill configuration. IntroductionDuring the past decade mill technology has evolved significantly in the following key areas:• improvements in variable speed motors continue with on-going advances in electronics;• ring motors, or gearless drives, are becoming more common in mill sizes 32 ft and larger, with ratings of 10 000 HP and greater;• geared drives have become available up to ratings of 9500 HP per pinion, compared to the earlier 6000 HP guideline;• improvements in speed reducer technology due to the use of carburized and ground precision gearing, make the high speed motor-speed reducer drive more competitive with the direct coupled low speed motor drive;• a unique speed reducer drive is being introduced to this industry which combines ring gear drive pinions with speed reduction. mprovement in gear alignment is claimed, and the overall drive arrangement is more compact than is possible with a conventional speed reducer drive;• the first 38 ft and 40 ft diameter mills have been designed and manufactured; and • application of large multi-shoe bearings have made shell supported mill configurations available for all, including the largest sizes. These designs have flat instead of conical mill shell ends, and have the potential for technical and cost advantages compared to conventional trunnion supported designs.This proliferation of mill design features provides several options to those involved in planning and design of milling plants, and requires more extensive evaluation to optimize mill design features to best suit specific project requirements."

Jan 1, 1999

By Michael P. Amsden

"THE ECSTALL CONCENTRATOR is situated adjacent to Highway 101 and the Ontario Northland Railroad, 15 miles east of Timmins, Ontario. Ore is delivered to the concentrator by rail from the mine, which is 17 miles northwest of the plant. Power and fuel are obtained from the hydro and natural gas lines which pass close to the plant site. Water is obtained from the Frederickhouse River, 6 miles east of the concentrator. The main concentrator building is a large structure 500 by 640 feet by 90 feet high and contains facilities for fine crushing, crushed ore storage, grinding, flotation, tin recovery, concentrate handling and reagent handling. Located in the same building are the machine shop, warehouse, metallurgical laboratory, pilot plant, men's change room, sample preparation area and an assay laboratory. The general concentrator layout is shown in Figure 47. Originally designed to handle 9,000 tons per day, the concentrator now treats 10,000 tons per day. Two different ore types are processed by selective flotation in three individual circuits to recover copper, lead and zinc concentrates. In 1973, another circuit was added to recover pyrite and tin concentrates from the combined zinc tailings of the three main circuits."

Jan 1, 1974

By G. Bourque

One of the design criteria for the Mount Wright facilities was to incorporate the latest proven automation techniques and devices for the new crushing, grinding and concentrating plant. The heart of the centralized control system is a Fox 1 process computer, located in the central control room in the administration building. The entire operation, i.e. crushing, conveying, storing, grinding and concentrating, is monitored and controlled, through the process computer , by one operator via a CRT console. In case of computer failure, the control is automatically, and without process interruption, transferred to manual back-up panels. One of the newest management tools, the process computer is programmed to collect and automatically print out shift. daily and monthly reports on tonnage, metallurgy and equipment operating time, for better planning of operations and preventative maintenance.

Jan 1, 1977

By K. Raht

LEAD poisoning is perhaps the oldest and, until recent years, the most misunderstood of all industrial diseases. Hippocrates appears to have recognized a relationship in the colic experienced by a patient who worked with metals, and the ancient literature is filled with references to the colics and 'dry bellyaches'. The colic and other sequalæ following drinking of lead-bearing waters and, particularly, wines has excited possibly more comment in the older medical literature than any other ætological factor. It was not until1656, when Stockhusen definitely connected the colic of the workmen with the fumes given off in the process, that the true danger to those working with lead was recognized. Unfortunately, something over 200 years elapsed before industry took any note of Stockhusen's discovery; it remained for Legge and Goodly and investigators of the early 1900's to forcibly educate their profession and industry to the manner in which lead gained entrance to the body. The work of Legge and Goodly was published in 1912 and the clearness with which these investigators presented the scientific data which they had accumulated will mark this volume as perhaps the first and most important contribution to our modern knowledge of the subject. It also ushered in a period when, in the short space of thirty years, lead poisoning has been reduced from one of the most baffiing and widespread o industrial diseases to one which can be anticipated and controlled. The next great contribution came in 1926 with the publication of the work of the Harvard group. Here, for the first time, was the physiological behaviour of lead laid bare, and it is to the discoveries of these authors that we owe our modern treatment of lead poisoning.

Jan 1, 1941