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By O. Hall

STOPING at Noranda" is a sequel to "Mining at Noranda". "Mining at Noranda", presented in 1937 (1), sketches Noranda's history, metallurgical problems, exploration, mining methods, mining details, pillar extraction, and costs. "Stoping at Noranda" deals in greater detail with our stoping, the use of sub-level drifts instead of benches, and the drilling out of the stopes with jointed rock drill steel and diamond drills. Sun-LEVEL DRIFT STOPING: Sub-level drift stoping is almost universal throughout the mine and is the standard sroping method in both sulphide ore and rhyolite flux ore. The features that have led to the adoption of this standard are: (1) Continuous symmetrical drilling in sub-level drifts with no delay for blasting. (2) Large-tonnage blasts Saturday night after the drillers have left. (3) Comparative freedom from gas and smoke during the working days. ( 4) The daily safety achieved by having all stope drilling done in drifts. (5) The safety and security achieved by drilling out stopes, floors, and pillars before there is any weighting or cracking.

Jan 1, 1939

By J. Paquin, P. Doiron, G. Proulx, P. Champoux

After nine years on a 36 hour schedule and two programs of creeping, the Alcoa Deschambault Potroom of faced the necessity of changing its organization for many reasons: the anodes butts were too small, the anode schedule was unbalanced, the iron content in the metal trends had increased, the metal tapping volume did not convene with crucible capacity and the liquid measurement task was delayed by tapping activities. A kaizen activity inspired the Potroom department to improve the organization. A team of 15 people including the process engineer, the process technician, team supervisors and Potroom operators developed a scenario, which would permit flexibility to creep pots if energy is available and an increase of added value production.This paper will describe the systematic approach, the communication method, the trials, the changes, and our success, along with the problems experienced by the team during the adaptation of Alcoa Deschambault Potroom organization over a 20 month period. Aluminium 2006 45th Annual Conference of Metallurgists ofCIM Montreal, Quebec, Canada Edited by

Jan 1, 2006

By D. Kulchyski, R. Thibault, D. Lamoureux

"Mine tunneling applications are sensitive to the leakage and friction performance of ducting systems. Improvements in performance can help project economics through reduction in drift height, booster fan spacing, fan electrical power requirement, and deferral of ventilation raise construction. Semirigid plastic ducting has enjoyed significant adoption in mine tunneling in recent years. This paper explores technical properties and performance aspects of this relatively new material application.INTRODUCTIONUnderground mining projects are sensitive to mine development cost and schedule to meet first production—both of which are defined to a substantial extent by mine access construction. The very nature of mine access development requires driving accesses into new areas and even mechanized and automated tunneling methods require ventilation. Until underground airways are connected, allowing a flow-through circuit, ducted ventilation is required to establish ventilation within any single-access (i.e.: dead-end) heading. See Figure 1 as an example of ducted ventilation. Improving performance of ducted ventilation systems impacts project cost and schedule in several ways:For drifts whose height is defined by overhead clearance above haul trucks or tall equipment, smaller diameter ducting will decrease heading size.With higher ventilation flows, activities can be less ventilation-constricted; secondary headings can be worked without restriction, which improves schedule.Given the ability to provide more air for a given fan power, blasting gasses can clear the face and mine more quickly so crews can return to work more quickly - allowing higher advance rates.Lower electrical costs – both due to lower power consumed by fans and with the requirement for fewer electrical stations to power booster fans."

Jan 1, 2019

By C. H. Dionne, J. A. Holmes, B. J. Huls

"Falconbridge Limited is presently developing flowsheet alternatives for implementation at the Strathcona Mill. The main thrust for change arises from the need to reject more pyrrhotite from the concentrate. To maintain appropriate levels of sulphur in the smelter concentrate, however, enhanced removal of non-sulphide gangue minerals must be realized. This could best be done in the Non-magnetics flotation circuit.Laboratory investigations were followed by an on-stream pilot test at Strathcona. The application of a column cleaner on the Non-magnetics concentrate resulted in significantly lower levels of fine gangue at equivalent sulphides recovery.This paper discusses the laboratory and pilot testing and results, with a focus on piloting. Also included is a discussion of the Strathcona Mill Flowsheet and the role of the Nonmagnetics flotation circuit.INTRODUCTIONFalconbridge Ltd. is currently developing means to reduce atmospheric sulphur dioxide emissions. One alternative is a reduction in the amount of pyrrhotite in Strathcona Mill concentrate, which reports to the smelter. Pyrrhotite in the Falconbridge ores contains an average of 39 percent sulphur and 0.64 percent nickel. By comparison, pentlandite contains an average of 33 percent sulphur and 34 percent nickel.A consequence of the rejection of pyrrhotite is a decrease in the sulphur assay in the remaining concentrate. This decrease causes downstream difficulties in the roasting process. Therefore, the content of non-sulphide gangue in the mill concentrate must also be reduced in order to maintain sulphur grades adequate for roasting. The resulting concentrate will have lower sulphur dioxide emissions while maintaining nickel production."

Jan 1, 1991

By A. Khan

The purpose of this paper is to demonstrate the value of identifying and optimizing throughput constraints by utilizing a Constraint Model. This will be achieved by first understanding the overall concept of Operational Excellence, Continuous Improvement and Theory of Constraints as practiced within Vale Canada Limited. Next, the value of utilizing a Constraint Model is demonstrated by primarily identifying constraints. The applications in utilizing Constraint Models will be demonstrated, including the primary benefit of identifying constraints. The remainder of the paper will focus on how to properly setup a Constraint Model using discrete simulation (regardless of simulation software). Benefits of understanding the severity of constraints and movement of the bottleneck will be recognized. The paper will conclude with the summary of real applications within Vale Canada Limited.

Aug 1, 2013

By Ali Montaser

This paper presents an experimental study conducted to facilitate the use of RFID on construction job sites. The study focuses on deployment settings to provide data acquisition with higher accuracy for indoor location sensing. It provides extension to the state-of-the-art in this field as it addresses the impact of metal media proximity to RFID tags, the reasonable duration for data capturing, number of RFID tags employed and the distance between them. Low cost passive RFID tags were used in the experiments where each tag is used as a reference point with a known location. Five hundred and forty (514) experiments were conducted in lab environment using a 3m by 3m test bed that is dynamically rearranged to generate 15 test beds and a total of 67713 data sets were collected and analyzed. The collected data were captured from nine locations for each test bed at four time intervals. Received Signal Strength Indicator (RSSI) was used as the main attribute for signal measurement to process the captured data. Results of the data analysis performed are studied under four main categories: duration, number of tags, locations of tags and metal interference. The best duration was found to be the 15 second in the test bed with the least number of tags; as the short amount of time to capture data did not allow creation of a lot of interference among the emitted signals. Within each test bed, errors occurred most at points where the received signals were not well distributed in a 360 degree vicinity of the data capturing point. It means that the center point of each test bed resulted in lowest errors and the points located on the extremities led to the highest errors. Finally, metal objects were found to have major impact on the accuracy of the captured data; to the level where reliable values for errors could not be calculated in the test beds attached to metal objects. In summary, the results of the experimental study and related findings are expected to provide guidelines to the users of RFID technology for localization in building construction.

Aug 1, 2013

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 S. Southall, F. McCaffrey, F. Stober, M. Darini

Electrode Columns are commonly used in electric furnaces to deliver current and regulate furnace power to the smelting or melting process. Hatch has developed an innovative patent-pending system for lowering ("slipping") and/or raising ("back-slipping") the electrodes through an electrode column, without requiring the release of any clamping devices. All clamping forces are applied by springs. Unlike systems employing hydraulically applied clamping forces, (e.g., water bladders) the spring system is failsafe. Its inherent simplicity virtually eliminates the need for maintenance. The Hatch system is particularly applicable to Soderberg electrodes, and comprises two axially movable slipping clamps and a stationary power clamp, each of which apply a distributed, radial clamping force to the electrode. The magnitudes of the slipping sleeves' clamping forces and sequencing of their axial movements are selected such that the slipping clamps, in conjunction with the weight of the electrode, provide slipping or back slipping without release of any clamping force.

Jan 1, 2005

By Jay Tuttle

THE spiral stoping method of mining was first seen by the writer at the Granby Consolidated Mining, Smelting & Power Company's Hidden Creek mine, at Anyox, British Columbia. Where the method received its name, or by whom it was named, is a question, but it was employed by the Granby Company at their Phoenix mine, in the Boundary district, B.C., as early as 1901-02 after they had tried unsuccessfully other methods at that large, law-grade property. its adoption there was suggested by two miners, John and Steve Swanson, then working at Phoenix, who had previously been employed in the hard iron-ore mines of Michigan and Wisconsin, where they had learned this system of mining. The method proved successful at Phoenix and also, later, at the Company's Hidden Creek mine at Anyox, where some 40,000,000 tons, or more, of ore was mined in this manner during a period of about thirty-five years.

Jan 1, 1939

By G. Halverson, K. Blower

"Giant Yellowknife Mines Limited (Giant) has been producing gold since 1948. Located at Yellowknife, Northwest Territories, Canada, see Figure 1, the mine processes approximately 1,200 short tons per day of 0.23 ounce gold per ton of ore.The majority of the gold in the ore is sub-microscopic and associated within the mineral arsenopyrite. This association complicates the extraction method since straight cyanidation will only recover 30% of the gold. The operations at Giant involve four essential steps, with an overall recovery of 87%. The steps shown in Figure 2 are crushing and grinding, flotation, roasting and cyanidation. These processes result in a number of effluent waste streams characterized in Table 1. These streams are combined and sent to a tailings storage pond for subsequent treatment prior to discharge to the environment.Giant is located just north of the 62nd parallel where winter temperatures drop to -40°C for extended periods. This entails storing effluent in dams over the seven month winter period for treatment during the relatively short summer season.The treatment method currently employed at Giant is an ""alkaline chlorination-arsenic precipitation-flocculation"" process. The pond water is subjected to three phases of treatment prior to being discharged to the environment as shown in Figure 3."

Jan 1, 1987

By M. C. Harris

"Excess Gibbs energy is a thermodynamic parameter which quantifies the difference between the value of the Gibbs energy for a real mixture and that for an ideal mixture. More specifically the partial molar excess Gibbs energy of a species (i) in a mixture is indicated by the change in the overall excess Gibbs energy of the solution as the number of moles of species (i) changes while keeping temperature, pressure and the number of moles of all other species in the solution constant. Generally it is obtained from the activity coefficient which in turn can be obtained for a species in a mixture using a variety of models. The most widely used method is to use UNIFAC. Flotation is probably the most important process in the concentration of minerals and requires the use of reagents such as collectors and frothers. There is abundant experimental data which illustrates that collectors of different alkyl chain lengths will change the contact angle and that frothers of different structures and molecular weights will result in changes in key flotation properties such as froth behavior, surface tension and critical coalescence concentration. In this paper it is shown that there is a strong linear relationship between measured parameters such as froth volume/height, surface tension, critical coalescence concentration and contact angle and the partial molar excess Gibbs energy of the molecules used. Proposals are made to explain these correlations.INTRODUCTIONAs is well known froth flotation is arguably the most widely used process in the separation of minerals. In broad terms the process relies on the use of reagents known as collectors to adsorb onto a mineral surface and thus render the mineral particle hydrophobic. Alkyl thiolates are very commonly used for this purpose. The hydrophobicity is induced as a result of the alkyl group’s molecular structural properties which results in it forming a non-ideal mixture with the process water. Surfactants (or frothers) are typically alcohols and are known to lower the surface tension of the system and also inhibit bubble coalescence and reduce bubble size. Since alcohols are polar they will also form a non-ideal mixture with water. The hydrophobic mineral attaches to the bubble and rises to the froth phase where the valuable mineral is recovered as a concentrate. Frothers have often been characterized using the so-called HLB (hydrophobic-lipophilic balance) number but recently it was shown that the use of activity coefficients (?) or excess Gibbs energy (G ex ), which is calculated using equation (1) is a much more appropriate way to describe the behavior of these reagents in non-ideal mixtures with water (Corin and O’Connor, 2014)."

Jan 1, 2016

By David Whalen

Mobile equipment in oil sand mining operations experience more maintenance problems than similar equipment in other surface mines, due to soft underfoot conditions. Oil sand properties are known to vary with temperature, bitumen content and previous loading cycles. One of the challenges is the widely variable underfoot pressure which supports shovels and trucks. In the case of a heavy hauler driving on in-pit roads, each tire is supported by a different ground stiffness resulting in an apparent uneven surface. Driving over uneven ground causes twist in the truck frame, which is transmitted to the dump body. Through a finite element analysis of a haul truck dump body, it was shown that slight frame twists produce localized stresses in the intersections of the floor stiffeners. These stresses are at times greater than those resulting from the maximum ore weight and are primarily responsible for cracking in these intersections. Syncrude maintains high quality haul roads, which are constructed of gravel, and makes every effort to keep the shovel pit roads as smooth as possible. This problem cannot be avoided through operational practices only and must also be accounted for in the design of haul truck bodies.

May 1, 2003

By W. H. De Blois

Introduction In the contact process for ?the manufacture of sulphuric acid, sulphur dioxide gas - produced by the burning of sulphur or of sulphur-bearing ores, or as a by-product in the treatment of sulphide ores - is made to combine with the oxygen of the air to form sulphur trioxide, which then only requires the addition of water to form sulphuric acid. The substance, as for example platinum, causing this combination is usually referred to as a catalyst, a convenient term, in the definition and explanation of which many pages have been written. Catalysis is now a comparatively common means of effecting chemical combination, but if the question were raised here tonight as to what actually goes on when this apparently innocent third party unites the parties of the first and second . part, without itself being altered in any way, I am afraid even our most learned members would have to confess their inability to entirely explain the phenomenon; for although the subject is under investigation, there is still much to learn. The contact process, however, is one of the outstanding achievements in chemical engineering. ? From the standpoint of the difficulties involved and the time absorbed in their solution, it probably stands alone in the field of technical chemistry. In fact, the manufacture of sulphuric acid has, from the earliest days, been surrounded with problems which have interested the ablest chemists. The Chamber System Although this paper has particularly to deal with the contact process, it may not be amiss to refer briefly to the chamber system, which was, and still is, a most important factor in the sulphuric acid industry.

Jan 1, 1927

By C. J. Brown

Regeneration of hydrochloric acid steel pickle liquors has traditionally been accomplished by pyrohydrolysis. However, a number of factors have recently conspired to reduce the attractiveness of this approach. Moreover, the process is not amenable to small-scale operations. On the other hand, the standard technique for regeneration of sulfuric acid pickle liquors, which is the low-temperature crystallization of ferrous sulfate is applicable to any size operation. A similar technique has recently been developed to regenerate hydrochloric acid. Sulfuric acid is added to the ferrous chloride-bearing spent HCl pickle liquor. The temperature is then reduced to below 0°C, resulting in the crystallization of ferrous sulfate heptahydrate and liberation of free hydrochloric acid. Depending upon the crystallization temperature, variable concentrations of sulfate are left in the regenerated acid. Although this residual sulfate has an impact on the pickling characteristics of the regenerated acid, tests have shown that by adjusting the conditions, pickling rates will be at least equal to those using pure HCI, and an acceptable surface finish will be produced.

Jan 1, 2006

By Donald MacFadgen

Since 1950, a total of 164 miles of levels and rooms have been roof-bolted in the collieries of the Dominion Coal Company. Roof bolting is an efficient and economic method of sup-port where heavy timber sets or steel booms are necessary for temporary roof support, or where conventional methods of support interfere with the passage of mechanical mining equipment. This paper discusses present roof bolting practices and special bolting applications. THE practice of roof bolting in be collieries of the Dominion Coal Company dates from 1950, when preliminary studies and experiments were carried out in a mechanized room and pillar section of Dominion No. 20 Colliery. These studies were made in close liaison with members of the United States Bureau of Mines who were conducting similar studies. Following the successful application of roof bolting in No. 20 Colliery, this method of roof support was introduced into other collieries

Jan 1, 1963

By Sylvie Brassard

Available information ?? InfoMine: mineral properties ?? Metals Economics Group: budgeted exploration expenses ?? MineScan: Canadian and American Mining Companies ?? Statistics Canada: Canadian Direct Investment Abroad, by Sector in the world OR all sectors by Country

May 1, 2008

By J. C. Allan

THE purpose of this paper is to outline the pogress made in the development o the gravity separation method o ore dressing known as Sink-and-Float, which, in the opinion of the writers, has now reached a stage justifying the claim that this new method marks a highly important advance in the technique . The essential feature of the newest development of this process is the extremely accurate separation achieved. This is responsible for higher extraction in the sink-and-float unit on coarse sizes and, in consequence, for substantially higher overall recoveries. Whilst this is the most remarkable feature of the new process, it has further important contributions to make to ore dressing under the following heads: (1) The introduction of the sink-and-float separator as a buffer helps to iron-out irregularities in the mill feed. By supplying a concentrate of constant grade to the flotation section, the process also indirectly improves overall recovery. (2) The addition of a sink-and-float unit to an existing mill results in substantial increase in capacity at low per ton capital cost. (3) Where the plant can be installed underground for the pre-treatment of low-grade ores, there is a saving in hoisting costs, and excellent 'fill' is provided near the point of use. ( 4) Low-grade mixed oxide-sulphide copper ores may be pre-concentrated, thereby producing a flotation feed sufficiently rich to render the oxide residue from such flotation economic for subsequent treatment by leaching or other methods. (5) Application of the process eliminates hard gangue constituents which cause high grinding costs, or gangue constituents which adversely affect flotation. The plant is compact and easily controlled. No highly skilled operators or expensive reagents are required, and the labour and power per ton are low. The separator is extremely flexible, working equally efficiently on any throughput up to its maximum capacity.

Jan 1, 1940

By Bertrand Robinson

Great advances have been made in rubber-lined pumps for the pumping of mill pulps. The Canadian Allis Chalmers alone report ov.er 300 such pumps put into service during the past four years. Pumps in which both the casing and the impeller are rubber covered have proved most economical in handling the usual run of mill pulps, effecting large savings in power, maintenance, and shutdown costs. For the handling of pulps containing comparatively large, sharper edged /articles, rubber-lined casings with hard iron impellers have been developed by the pumping departments of Hollinger and Noranda. These rubber-iron combination pumps show an appreciable reduction in overall pumping costs as compared with the all-rubber and the all-iron pumps. The power efficiency is lower in rubber-iron than in all-rubber pumps but higher than in the all-iron pumps, with lower replacement costs due to the cheap iron impellers used. Where continuous operation is essential, however, and duplication of units to take care of shutdown time for replacement of parts is not within the expenditure budget of the company, all-rubber pumps are being used t0 a greater extent. As in all items pertaining to milling operations, the economics of the situation must be studied as closely as the technical details, to arrive at the most advisable practice.

Jan 1, 1939

By W. L. Sherwood

Present conventional techniques for primary steelmaking in both integrated and non-integrated plants are outlined. 'Direct reduction' alternatives are reviewed and categorized according to the nature of the product produced, with particular emphasis on the limited number designed to yield steel as the end product. A proposed new technique, referred to as the Sherwood Process, is described in some detail as a new combination of selected features from the prior technology. This process is in-tended to realize, in integrated operations, the result of continuons steelmaking directly from the ore in a single plant and, in non-integrated operations, continuons steel-making from a metallic charge of scrap, sponge iron or pig iron. Prominent features are continuons processing in elongated, horizontal, rotary furnace equipment, controlled direct heating of each process stage and, for the over-all integrated process, a size separation for removal of excess solid reductant and other waste just prior to the melting step. Material and energy balances are presented as well as exemplary cost data. Reasons for selecting this particular combination of process elements are dis-cussed.

Jan 1, 1968

By Howard W. Tipper, Richard B. Campbell

"The Quesnel Trough is underlain by a thick sequence of mainly Upper Triassic and Lower Jurassic volcanic-clastic and sedimentary rocks that lie between the highly deformed Proterozoic and Paleozoic rocks in the Omineca Geanticline to the east and the Upper Paleozoic Cache Creek Group in the Pinchi Geanticline to the west. Broad areas of the Trough between Kamloops and Williams Lake are covered by Eocene volcanics and sediments and by Miocene-Pliocene plateau lava. Granitic intrusions were apparently mainly confined to two major episodes; one about 200 m.y. ago (coeval with the Guichon batholith) and one about 100 m.y. ago. In addition, the region includes small granitic and syenitic intrusions, some porphyritic, that may be all or partly still younger. Exposures in the region are generally small and scattered, obscured by widespread, not necessarily thick glacial deposits. This, together with the extensive Tertiary cover, makes prospecting difficult. The part of the Quesnel Trough discussed here is the direct northwest-ward extension of the copper-rich Kamloops-Merritt-Princeton region. It contains the Boss Mountain molybdenum mine, related to a breccia zone induced in a batholith of the oldest group by a younger intrusion, and the Cariboo Bell copper deposit in Lower Jurassic volcanic-elastic rocks and syenitic intrusions. The Gibraltar deposit, in a 200-m.y. intrusion, is within the Pinchi Geanticline close to the margin of the Trough. Molybdenum prospects are mainly restricted within or near the 100-m.y. granitic rocks. Copper prospects, on the other hand, are most prominent in the volcanic-elastic rocks and in the 200-m.y.-old granitic rocks, although they can also be spatially related to younger intrusions. Copper thus has a wide potential distribution.The writers believe that the region is deserving of careful and comprehensive exploration by directly applying the knowledge and techniques developed in the important producing areas to the south. All of the major pre-Tertiary geological elements seem to have potential for mineral deposits; none should be ignored. A thorough knowledge of the thickness and distribution of the Tertiary rocks and the development of geophysical methods to ""see through"" them is of particular importance."

Jan 1, 1970