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By S. Eckert, M. Reuter, O. Keplinger, D. Obiso, N. Shevchenko, M. Akashi

We report on laboratory experiments focusing on bubbling phenomena arising from gas injection through a top submerged lance (TSL) in a liquid metal layer. The objective of this study is to reveal the characteristics of the formation and behaviour of the particular bubbles at different gas flow rates and submergence depths of lance. Visualization was performed in the eutectic alloy GaInSn using X-ray radiography. Argon bubbles were injected through the injection positions at three different submergence depths. Essential parameters such as the bubble size, bubble shape, detachment frequency and the two- dimensional gas distribution in the flat vessel were obtained by image processing. The results show that the deep position of the submerged lance causes an asymmetric large-scale circulation inside the fluid vessel. Bubble detachment frequencies were calculated by Fast Fourier Transformation from fluctuations of the image intensity in the vicinity of the nozzle injection point. This frequency does not show strong variations with respect to changes of the gas flow rate and the submergence depth of the nozzle. An increasing gas flow rate results in an increasing two-dimensional projected bubble area and the occurrence of a significant number of small bubbles being trapped by the strong fluid flow in the liquid metal layer. INTRODUCTION The Top Submerged Lance (TSL) process has been an essential component of the metallurgical industry since the emergence of first concepts about 50 years ago (Floyd, 2005). The process, which is characterized by blowing reactive gas through the submerged lance into a liquid bath, was developed mainly for improving the tin smelting process and has been applied for waste treatment or the production of several metals such as copper, lead, nickel and zinc. The productivity of the reactor is determined mainly by the efficiency of the chemical reaction between the gas or solid particles and the liquid. To achieve a high efficiency requires good exchange between the gas-liquid phase and therefore a large interface area. The efficiency changes greatly with the number and size of bubbles injected from the nozzle and the extent of splashing on the free surface. The degree of turbulence in the bath plays a decisive role here. For the reason, the design of an efficient TSL process requires a profound knowledge of the fluid dynamics especially for complex multiphase flows.

Jan 1, 2019

By D. P. Wilkinson

There are significant global environmental and supply issues with existing energy paths today . Global emission and fuel regulations, global fuel and power structure, energy security, and cost are driving new technology and non-conventional approaches . Fuel cells will play a significant role in the strategy to effect positive global change, increase fuel efficiency and decrease dependency on traditional fossil fuels. Fuel cells do not require recharging, just refuelling and a wide range of fuels are possible with hydrogen being the most desirable. Technical progress as well as investments in fuel cells for transportation, stationary, portable, and micro fuel cell applications have been dramatic in recent years. The present view is very optimistic for fuel cell power generation and the status is presently at the field trial level, or early commercialization stage, moving into volume commercialization. A number of demonstration programs are in progress worldwide such as the California Fuel Cell Partnership which involves original equipment manufacturers (OEMs), fuel providers, transit authorities, state and government bodies. Fuel cells and a hydrogen infrastructure are key to a long-term solution to global energy issues. Fuel cells will need to be competitive on an economic basis with the established and highly developed internal combustion engine and other forms of power generation There has been significant technical progress in a number of fuel cell areas including power density, transient / dynamic response, multiple fuels, cost potential, reliability and durability. However, significant technology gaps still remain today. This presentation will focus on the status and progress of the fuel cell today, current fuel cell research and development, the challenges going forward, and the future view of the fuel cell and it's impact on global energy issues.

Jan 1, 2005

By Z. Xie

Gas diffusion electrodes (GDEs) for high temperature polymer electrolyte fuel cells (PEFCs) have been prepared using ZrP-modified Nafion ionomer. The performances of these GDEs as cathodes and anodes were evaluated and compared with conventional Nafion ionomer GDEs using Nafion 112 as the PEM under elevated temperature and reduced relative humidity. ZrP-modified Nafion ionomer was incorporated into the catalyst layer to enhance water retention and/or increase the protonic conductivity. The fabrication of ZrP-GDEs was implemented by the ion exchange of Nafion solution with zirconyl chloride, followed by the impregnation of GDEs in H3PO4 solution. The composite electrolytes in the catalyst layer possessed a ZrP content of 20% by weight. GDEs were characterized by TGA, SEM, XRD, and CV. Scanning electron microscopy (SEM) indicated evenly distributed elemental Zr and P within the catalyst layer. Cyclic voltammetry shows a reduced electrochemically-active surface area when the ZrP is incorporated into GDEs. Polarization and impedance analyses indicate the cathode with ZrP-modified Nafion ionomer did not show an enhanced or decreased performance, compared with conventional Nafion ionomer GDEs under elevated temperature and decreased humidity. However, when GDEs with ZrP¬Nafion ionomer were used as the anode, an improved performance was observed. Preliminary experiments show that the anode is more sensitive to dehydration than the cathode under elevated temperature and/or low humidity. Improving the anode water retention capability will help to reduce losses at the anode. However, the incorporation of hygroscopic agents in the cathode catalyst layer is not essential because it is self-humidified by electrochemically-produced water even under elevated operating temperature and lower humidity.

Jan 1, 2005

By DALE MacGREGOR, VERA TUREK

lndusmin Limited acquired the St. Donat quartzite deposit in 1967 to produce high-quality silica for use in the sandblasting and silicon carbide industries. The quartzite, of Grenville age, is highly friable and porous. This is due to numerous small, kaolinite-coated cavities in the quartzite; the cavities were formed through leaching, probably by rising hot solutions.

Jan 1, 1984

By Michel Aubertin

Les activités minières peuvent produire de grandes quantités de roches stériles, qui sont typiquement entreposées dans des empilements de surface, au dessus la nappe phréatique. Ces haldes peuvent occuper une superficie de plusieurs dizaines d?hectares, et s?élever à plus de cent mètres. Pour des exploitations en roches dures, les roches stériles ont usuellement une granulométrie qui contient des particules de la taille d?un sol silteux jusqu?à des cailloux et blocs de taille métrique. La structure interne d?une halde construite sur une surface relativement plane comprend généralement deux zones principales. La première zone se trouve au coeur de l?empilement, et elle est formée par la présence de plusieurs stratifications subhorizontales (avec des couches denses et lâches) due à l?effet des équipements lourds qui compactent et brisent les grains. La deuxième zone se trouve aux endroits où les stériles ont été déversés en crête, par des camions ou des butoirs, ce qui induit une ségrégation des particules sur les flancs, le long de la pente. Selon la séquence de mise en place, la distribution granulométrique et la hauteur des bancs, un grano-classement plus ou moins développé se produit, avec les particules les plus grosses au bas de la pente et les particules plus fines au sommet ; on observe aussi une stratification inclinée due à l?avancement latéral du front de déposition. Ces éléments de la structure interne d?une halde influencent la distribution et le mouvement de l?eau (et de l?air). Pour évaluer la distribution des propriétés des matériaux dans une halde, on doit usuellement avoir recours à une combinaison de techniques qui fournissent des informations sur les caractéristiques hydrogéologiques et géochimiques des roches stériles. A cet égard, certaines techniques géophysiques sont particulièrement intéressantes car elles permettent une cartographie tridimensionnelle des variations des propriétés. Les informations obtenues de diverses techniques de mesures utilisées conjointement peuvent alors être employées afin de construire un modèle numérique qui permet d?analyser les écoulements non saturés de l?eau et le transport réactif des contaminants. De telles simulations aident à mieux comprendre la réponse de la halde dans son état actuel et futur, ce qui fournit des arguments pour ajuster la séquence de déposition pour élaborer le plan de fermeture et pour sélectionner la stratégie d?instrumentation et de suivi de l?empilement. La présentation inclura un survol des diverses techniques qui ont été développées afin de caractériser les propriétés des matériaux en laboratoire et sur le terrain, et pour obtenir un portrait global de la structure interne d?une halde. Des résultats additionnels sur la modélisation du transport réactif seront aussi montrés afin d?illustrer l?influence de la structure interne d?un empilement sur sa réponse hydro-géochimique et environnementale.

Nov 1, 2008

By BARRY BANNATYNE

About 90 per cent of Manitoba's industrial minerals production is for structural materials. Most of these come from the Paleozoic rocks west of the Precarnbrian Shield, or from glacial deposits that are extensive throughout Manitoba. The major raw materials are sand and gravel, and carbonate rocks for crushed stone (and also dolomite for high-magnesia lime, high-calcium limestone for lime and Portland cement, and dolomitic limestone for Tyndall stone). Glacial lake clays are used both in cement and in lightweight aggregate. The Jurassic and Cretaceous strata exposed along or near the Manitoba Escarpment include siliceous, carbonaceous, kaolinitic and illitic shales, all of which are quarried by Red River Brick and Tile in the Pembina Mountain and Ste. Rose areas for use in a brick plant at Lockport. Non-swelling bentonite near the base of the Pembina Member of the Upper Cretaceous Vermilion River Formation is of value as an absorbent clay, and is the only commercial source in production in Canada. It has been quarried by Pembina Mountain Clays Limited since 1940. Gypsum occurs in the Jurassic Amaranth Formation and supplies much of the market for wallboard and Portland cement additive in the Prairie Provinces. Quarries are operated at Gypsumville by Domtar Construction Materials Limited, and north of Amaranth by Westroc Industries Limited. Silica sand from the Ordovician Winnipeg Formation is of glass-grade quality, and about 100,000 tonnes are produced annually by Steel Brothers Canada Limited on Black Island . It is used as a glass sand, as foundry sand, for sand blasting, and as a filter-bed sand .

Jan 1, 1984

By T. Melfi, M. James

Attaining required mechanical properties in welds made using the double submerged arc welding (DSAW) process is difficult, and it is becoming more difficult as the strength level of the base materials continues to increase. Producing weld metal with adequate mechanical properties involves factors that are often overlooked and not taken into consideration. Not least amongst these problems is simply finding information to use in selecting the appropriate flux/wire combination. Most of the available data on flux/wire combinations provided by consumables manufacturers is generated using the multiple pass welding procedures required for classification per specifications such as AWS A5.17 and A5.23. This data really gives no insight into the properties that can be expected in a DSAW application. Also, base plate composition plays a very significant role because of the fact that base plate dilution can be as high as 70% in DSAW welds. This means that if any elements are present in the base metal that are deleterious to mechanical properties, they will also be present in significant quantities in the weld deposit. Some of these elements can decrease toughness and increase hardness (increased hardness is a concern if the pipe is intended for sour service). Some of these problems can be mitigated by proper selection of welding consumables. Selection of proper welding consumables means selecting an electrode that provides the appropriate alloying elements to obtain the desired level of impact toughness while also keeping the hardness within any specified limits. In order to attain the necessary impact toughness, selection of a flux with an appropriate composition (in terms of its basicity and its ability to control the nitrogen content of the weld deposit) is required. As with all welding processes, the mechanical properties of DSAW welds are also highly dependent on the welding procedures. This work clarifies how to select appropriate consumables to meet a given set of requirements, and also how to achieve the optimum mechanical properties from those consumables.

Jan 1, 2005

The paper will cover the basic reasons for alkaline leaching, a brief description of the circuit and the reasons for the flowsheet used. Changes made to the flowsheet, including the use of mechanical agitation of pachuca slurry, the use of oxygen and its effect on extraction, the use of lime and its effect on process economy, and the environment, will be described. A brief description of a unique semi-autogenous mill and future circuit changes will be included.

Jan 1, 1979

By Unkown

The Province-wide road ban on movement of heavy loads has had the effect of curtailing or stopping development in several areas. In the Leduc area, the discovery well has been restricted in flow to only a fraction of normal due to limited storage space, but drilling at Imperial Leduc Nos. 2, 3, and 4 has been continued for the past few weeks. The No. 2 well is within 100 feet of the producing horizon and should be completed within the next few days. According to reports, it has been logging slightly lower, structurally, than the discovery well, but, regardless of the outcome, it has been an important test to determine westerly cross-section of the Leduc structure. No official reports have been made available of any tests made during the drilling of the well, but it is understood that promising oil and gas shows have been indicated in higher formations. Actual drilling operations have not been commenced by any of the other companies holding leases in the immediate area but it is expected that, when road bans are removed and equipment is assured, several wells will be commenced. Announcement has been made that Imperial Oil, Limited, will drill a well near Battle lake, about thirty-five miles southwest of the Leduc field. Location of the well has been made following an extensive seismograph survey of the area, with total depth of the test well expected to be in the 8,000- to 8,500-foot range. Drilling will be done with the heavy-duty rig last used at the De Winton test. Imperial Oil have abandoned hope of oil production in the Provost area after drilling nine wells, but will retain their interest in the gas field that has been developed. Of the wells drilled, four indicated gas flows ranging from 1,060 to 13,200 M.c.f. per day.

Jan 1, 1947

By W. E. Cockfield

"The Last Chance claim is about 13 miles north of the village of Nicola and northeast of the city of Merritt; in the south-central part of British Columbia. It lies within Nicola mining division on the northern slope of Swakum mountain; near its summit. It may be reached by means of a branch road from the Kamloops-Merritt highway that leaves the highway at Nicola.The property was originally staked as a copper prospect by Oscar Schmidt in 1916. A number of cuts were driven and a test shipment of 22 tons of ore, averaging 4.6 per cent copper, was made from the surface showings. The property was then optioned to Granby Consolidated Mining, Smelting and Power Company, Limited, who did a small amount of drilling, after which the option was abandoned. The same year an option was secured by Northwestern Mines, Limited, of Spokane, and a SO-foot shaft was sunk. This option also was abandoned and after a number of years the property lapsed, but was re-staked in 1942 as a tungsten prospect along with other claims, and was drilled for the Metals Controller in 1943."

Jan 1, 1954

By Oscar F. Tangel

This paper outlines Canada's current status in world iron ore markets, and evaluates the prospects for the future. Estimates for the production, export and consumption of iron ore are given. Canada's major market will continue to be the United States, with the European Common Market countries, Japan and the United Kingdom also forming important outlets. The advantages held by Canada's major competitors in these latter three market areas are briefly discussed.

Jan 1, 1966

By Wataru Inagaki, Kozo Kawano, Tetsuya Ando

Cu–Ni–P alloys are the typical precipitation-hardening material. Thus, Cu–Ni–P alloys is expected to apply alternative materials for heat-exchanger tubes. Therefore, it was investigated that the effect of the heat-treatment simulated brazing on mechanical properties of Cu–Ni–P alloy in this study. The hardness of specimen as heat-treatment simulated brazing after solution heat treated (sht) was shown approximately 105 HV. The peak hardness and tensile strength of the specimen as performed aged at 498 K for 43.2 ks following the heat-treatment simulated brazing achieved at approximately 140 HV and 260 MPa, respectively. From these results, it is expected the application to higher-strength tube for heat-exchanger after brazing in a furnace. INTRODUCTION Copper prices have increased dramatically with high in recent years. At the same time, manufacturing industries are required to reduce the environment load by reducing the wall thickness of the copper tubes used in heat exchangers. High-strength copper alloys are developed for reducing the wall thickness, while achieving high strength, of the copper tubes. Moreover, excellent workability and corrosive durability are also required by these copper tubes. Furthermore, the brazing, which are carried out at about 1050 K during the assembly process of heat exchangers, leads to grain growth and re-solving of additive elements. Nomura et al. achieved a tensile strength and Vickers hardness of approximately 260 MPa and 110 HV, respectively, after aging at 723 K for approximately 36 ks. Tamagawa et al. studied that the strength of Cu–Ni–P alloy rapidly increased at about 125 HV during the cooling process after the heat brazing due to the Ni2P precipitates sized 5–10 nm. Furthermore, Inagaki et al. achieved a Vickers hardness of approximately 130 HV by aging at 498 K for 10.8 ks. In the present study, we focused on the lowest aging temperature of 498 K in the previous study, and investigating the effect of heat-treatment simulated brazing on the mechanical properties of the Cu–0.93 mass%Ni–0.24 mass%P alloy.

Jan 1, 2019

By H. E. T. Haultain

Research is a much over-overworked word, sometimes a much abused word; the result of this has been that many who really need the word avoid it, shy away from it just as we do from that most useful word camouflage. We have not been altogether happy in our substitutes. Some years ago I spoilt a very good proposition by using the word investigation. There were those who thought that men and methods were to be investigated instead of simply processes. They expected disruption instead of co-ordination. The bad psychology up-set the scheme. The word experiment is even worse in its psychology. To the mind of the "practical" business man experiment denotes ignorance, waste of time and money and presupposes failure. It is not so long ago that the recognized way of improving the methods about a mine was to get a new manager. Until comparatively recently the average life of a boss in a mine in the West was under, rather than over, two years. Certainly was this the case in the smaller mines. Directors did not recognize that a cock-sure new boss was a greater experiment than a certain amount of feeling-his-way on the part of the old one. We always say that no two mines are the same but we are only now realizing to what extent the fine points of the game can and must be learnt on the job itself. One of the main differences between a small property and a large one lies in this study of the fine points of the game. In the early stages operation is the main point-get her going and keep her going.

Jan 1, 1924

By Richard Q. Fox, Joe L. Pinson

This paper provides guidelines jo1• analyzing and selecting electric power demand controlled. Error calculations, load selections and timing criteria are identified as the three key functions which affect the suitability of a demand controller for any particular application. The advantages of simulating the demand control application on a computer are described, and applications of a demand controller to an iron ore concentrator and a copper refinery are shown. Finally, the paper studies the return on investment for a demand controller.

Jan 1, 1976

By M. Piard

The scarcity of literature referring to mines in the Rockies has compelled the writer to co-ordinate information and advice taken at the very source. Help was gladly given by active inspectors and mine bosses. Although the field is unimportant at the present time, due to its distance from markets for raw coal, it is quite worthy of the attention it is receiving from two continents; for, with the commercial synthesis of liquid fuels, it would become the largest fuel laboratory in the world, provided, of course, that freight cost drops to a low comparative level. As explained below, there are no obstacles to economical and safe operation under anything like the typical outcrop shown in Figure 1. Although coal dust is probably more dangerous in the Rockies than anywhere else, the damp outcrops afford means of control. The abundant gas may be bled to the open air, and the rigid roof will settle gradually under a wide span of opened outcropping. The Panel Retreating Wall The Measures: Coal measures having an attitude similar to that shown in cross-section in Figure x are characteristic of the active coalfield on the Alberta side of the Rockies, and they are also found on large tracts of undeveloped land west of the divide. The small anticlines, not shown in the cross-section, do not affect the progress of a pillar line, provided their crests are connected to the atmosphere by drainage bore-holes.

Jan 1, 1928

By Thomas E. Shumka

ASTM E2905 describes a two-part standard for electromagnetic methods for preparation and examination of ring gear teeth in the mining sector for SAG and Ball Mill ring gear drives, including pinions? particularly on the addendum, dedendum, and root areas. This practice addresses the need to detect surface breaking flaws electronically and to have the ability to accurately size any surface breaking cracks found on cast and forged SAG and ball mill ring gear and pinion teeth faster and more effectively than other methods. Eddy-current surface arrays are seeing increasing use throughout the industry for the detection of surface breaking flaws in conducting materials. Example applications include examinations of pipelines, bridges, engines, aerospace structures, and any conducting material for surface breaking flaws including cracks. In addition, model-based methods are being used to size cracks accurately found in the addendum, dedendum, and the root of SAG and ball mill girth gear teeth. As visual interpretation of a surface breaking discontinuity on gear teeth is the normal analysis, the colors and 3D images that are provided with this technique, help with visualization and therefore are absolutely invaluable in such circumstances. This practice will help to standardize the use of this nondestructive testing approach.

May 1, 2013

By E. Ettles

This paper features some of the spectacular new advances in the fields of fluorescent penetrant inspection and magnetic particle concentration. Casting fractures in the various stages -before the repair, during the repair and in the completed repair -using the cold process method will be discussed. This cold method of repair eliminates problems of pre-heating and cooling and the stress factors that are involved in any heat repair.

Jan 1, 1971

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

By Y. Sugiyama, K. Kitazono, T. Miura, K. Matsuo

"Impact energy absorbing system for automotive is an important technology. Open-cell porous aluminum alloys were manufactured through Powder Bed Fusion (PBF) process. Compressive properties of the porous aluminum alloy depend on the cell structure as well as the porosity. The authors manufactured two ordered cell structures, truncated octahedron and rhombic dodecahedron, and one disordered cell structure, random Voronoi structure using a 3D-CAD software. Compression tests revealed the anisotropic deformation of the porous aluminum alloy with ordered cell structure. On the other hand, the porous aluminum alloy with disordered cell structure showed relatively isotropic and uniform deformation, which is suitable for energy absorbing applications. Therefore, controlling the disordered cell structure designed by Voronoi diagram enables to develop the advanced porous aluminum alloy having various mechanical properties.INTRODUCTIONAdditive manufacturing (AM) process enables to manufacture near net-shape mechanical parts. The AM technology is typically focused on titanium alloys due to their high specific strength and biocompatibility (Attar, 2014). Recently, aluminum alloy parts can be manufactured through selective laser melting method (Leary, 2016). Metal foams or porous metals are lightweight cellular materials having closed-or open-cell structures (Banhart, 2001). Aluminum foams are focused on as an energy absorbing material for transport industries (Baumeister, 1997). The purpose of the present study is to investigate the optimal cell structure of open-cell porous aluminum alloy manufactured through AM process. Most previous researches on the AM aluminum lattice structure has been considered ordered and periodic cell structures. On the other hand, classical aluminum foams manufactured through cast or powder metallurgical processes have disordered and heterogeneous cell structures (Körner, 2000). The authors use a concept of Voronoi diagram (Moukarzel, 1993) in order to manufacture various cell structures."

Jan 1, 2018

By R. Heikkilä

As a part of a large research and development program in Finland, a system calibration for an UAV measurement method having practical experiments in a Jorvas Railway Yard design and construction project. The Railway yard construction are was measured using an UAV measurement device by Smartplanes (Smartone) and using some reference points measured by a GNSS device. The measured data was cleaned, combined and adjusted through Least Squares Optimization using the software developed by a Finnish company Pieneering Oy. As references, two different laser scans as well as total station surveys were used. For applicability evaluation, the accuracy of measurement, the reliability of measurement, and the economy of measurement were used. Based on the comparisons, the achieved precision of the UAV measurement was high, instead the accuracy of measurement was not sufficient in this case. The principle of this photogrammetric measurement includes a lot of redundant observations making it possible to achieve a high level of reliability. The economy in this Railway Yard Design project was not able to achieve.

Aug 1, 2013