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By C. G. McLachlan

INTRODUCTION The work described in the following paper was under-taken with a view to determining, if possible, the relative importance of some of the phenomena on which flotation seems to depend, in the hope that, if this information could be obtained, it would be of value in dealing with the problem as a whole. At the outset, brief reference will be made to three papers which had a considerable bearing on the course followed in the present investigation. In 1919, Langmuir, in a paper on 'The Mechanism of the Surface Phenomena of Flotation', showed that mono-molecular films of very great stability could be produced on solid surfaces with oleic acid, but that pure paraffin oil, though spreading readily on a dean dry surface, was easily displaced by water.

Jan 1, 1926

By A. E. Hall

"This paper summarizes findings of a two-month investigation in Zambia and Zimbabwe and a one-month visit to Britain in1990-1991. United States contacts have supplied information about that country.Zambia's political unrest and severe devaluation, combined with developments in Namibia and South Africa, enhanced staff recruiting problems in the School of Mines. Zimbabwe has a strong and developing mining department. The departments of mining in the United States and Great Britain are readjusting and contracting due to the reduction in the scale of the industry.The above factors are reviewed and their impact on the countries evaluated.IntroductionCanada trains the majority of its mining engineers domestically but a significant number are recruited from other countries. Examination of the qualifications of 200 professional engineers registered in the mining discipline in British Columbia showed that125 received their first degree from a Canadian university, 33 graduated from institutions in the United States and 42 from the rest of the world including 30 from the United Kingdom. This is a rough and-ready sample but it indicates that developments in the education of mining engineers in the United States and in Britain are relevant to the Canadian mining industry.The recent changes in the world economy and political structure have significant implications for the mining industry and for the supply and training of engineers. Change in eastern Europe coupled with the downturn in mining, especially in the European coalfields, has enabled many engineers to travel freely to the West. The low gold price and the legislative changes in Africa that have improved access to education for Africans with the ability to fill responsible positions, have reduced the South African mining industry’s overseas recruitment to a minimal level. The Australian recession has also lowered their recruitment of mining engineers from other countries."

Jan 1, 1993

By O'Halloran. Gerard F.

"ECSTALL MINING has installed in their plants the most modern equipment in the mining industry. At the minesite, digital blocked frequency controls are used to monitor all crushers, conveyors, ventilation equipment and pumps from underground. Distant pumping stations are monitored and controlled by radio. Modern friction skip and cage hoisting systems have been installed with static power supply designed for automatic operation. Rotary-type compressors of recent design are in service in place of the conventional reciprocating-type units. At the concentrator, the 800- and 1500-hp synchronous motors driving the grinding mills have static field excitation and pneumatic clutches, still meeting modern-day concepts, having been• installed in 1966. The maintenance work load has increased annually for the past eight years. The modern plant, with all the present-day sophistication, must have a welltrained and well-organized force of skilled workers, and a maintenance system which will supply realistic facts and guidelines. This presentation will review the relative location of plants, utilities, maintenance and services, plant maintenance control and mechanical control. It is the hope that enough information will be presented to weigh the size of the job and how the resources are utilized for controlled maintenance."

Jan 1, 1974

By F. Liu, H. A. Meier, D. M. Valiveti, P. A. Gordon

Hydraulic fracture is a frequently used technique in the Oil and Gas industry to create high permeability pathways for extraction of hydrocarbons. Numerical simulation of this method poses challenges such as representation of 3D fractures, propagation of randomly oriented fractures in 3D media, enabling fluid leak-off from fracture to poro-elastic medium. We have developed a numerical model using the Generalized Finite Element Method (GFEM) to simulate fluid driven fracture in a poro-elastic medium that addresses these challenges. In the GFEM framework, special enrichment functions are used to augment the solution space in the displacement and pore-pressure fields in order to accurately capture the response in the vicinity of the fracture. Adaptive refinement of the finite element mesh is also employed to facilitate accurate and efficient solution of the model. Our model fully couples fluid flow in the fracture, represented with the lubrication approximation, to the geo-mechanical behavior of the bulk poroelastic rock, comprised of an elastic rock skeleton saturated with fluid. Fracturing fluid exerts traction on the fracture surface and is also allowed to leak-off into the poroelastic medium using a transfer function approach. Stress intensity factors (SIFs) are evaluated based on the Contour Integral Method, accounting for the fluid pressure on the fracture surface. The SIFs are used to govern a full 3-D evolution of the fracture. Verification of the model is performed for known behaviors for the poroelastic response and fluid flow in the fracture.

Jan 1, 2015

By Alain Simard, Sylvain Lacroix, Louis-Martin Dubé, Pierre Pilote

"The Harricana-Turgeon belt (HTB) is a poorly known volcano sedimentary belt in the NW part of the Abitibi Sub-province; it includes the Matagami, Joutel, Brouillan and Casa-Berardi mining districts. The HTB is dominated by volcanic rocks, which covers 65% of its surface area, followed by sedimentary (18%) and plutonic (17%) rocks. It is also transected by numerous deformation zones located either at the contacts of volcano-sedimentary units and granitoid bodies or cross-cutting them. A preliminary geological synthesis shows that mineral deposits are associated with certain regional geologic elements.The volcano-sedimentary units are grouped here into twelve band-shaped lithotectonic domains, most of which extend for more than 150 km E-Win the HTB. Each domain is defined by lithologies and facies associations, and gradiometric and electromagnetic signatures.Eight domains are composed of basaltic or basaltic to komatiitic associations, interlayered with thin pelagic sediments, representing sub-marine lava plains. Two domains are composed of basaltic to rhyolitic associations that are interpreted as volcanic arcs formed by one or several central volcanic complexes.The sedimentary rocks are grouped into two lithotectonic domains. Each is composed of rhythmic sequences of turbiditic sandstone- siltstone-shale, Algoma-type banded iron formations and conglomerates bearing plutonic and volcanic pebbles. These three facies come partly from mass flow at the bottom of a slope in a moderately deep marine environment. In each domain, a conglomerate sandstone- siltstone sequence, containing poly genetic pebbles of local provenance, is similar to Timiskaming-type alluvial deposits.The nineteen granitoids, found within the HTB and at its border, belong to numerous petrographic suites, and have been grouped into four structural families: pre-tectonic, pre- to early-tectonic, syn- to late-tectonic, and late- to post- tectonic. The pre- to early-tectonic plutons are presumed to be sub-volcanic and are generaly associated with the volcanism of central complexes.The HTB mineral resources consist essentially of polymetallic (Cu-Zn-Ag-Au) and gold (Au-Ag) deposits. The polymetallic deposits are located exclusively in the two lithotectonic domains composed of basaltic to rhyolitic associations (Matagami-Brouillan and Joutel Raymond). All gold deposits are associated with deformation zones superimposed on lithotectonic domain contacts and highlighted by graphitic units. Most of the deposits are hosted in the Casa-Berardi and Douay deformationzones, located at the contact of the Cartwright basaltic to komatiitic domain and the Taibi sedimentary domain"

Jan 1, 1990

By Alan Jessop

A small group has been set up at the Dominion Observatory, Ottawa, to make a survey of terrestrial heat flow throughout Canada. Terrestrial heat flow is the heat rising from the interior of the earth and escaping at the surface, and is calculated from a knowledge of under-ground temperature distribution and the thermal conductivity of rocks. A small number of diamond drill holes are being sunk for the purpose of measuring temperatures below the surface, but the program is inadequate for a thorough survey. Mines and holes drilled for other purposes are being sought by the Dominion Observatory group to supplement their own drilling program. F ROM January, 1.962, to December, 1964, geo-physicists of many nations will be cooperating in the "International Upper Mantle Project." Unlike tl1e International Geophysical Year, which was mainly concerned with the fluid layers surrounding the earth, the Upper Mantle Project is an intensive study of the solid earth. Canada, with its large land area and extensive Precambrian Shield, is an active participant in the project.

Jan 1, 1964

By D. Karpoff

"IntroductionUNTIL the recent discovery and development of deposits at Allard Lake, on the Lower Romaine river, practically the whole of Quebec's - and indeed of Canada's - production of ilmenite had come from deposits in the vicinity of St. Urbain, Charlevoix •county, a village about eight miles north of Bay St. Paul on the north shore of the St. Lawrence, some sixty miles below the city of Quebec (see Figure l) . Although these deposits were known nearly three hundred years ago and were worked in a small way during the years 1872-74, when a charcoal blast furnace was operated by the Canadian Titanic Iron Company for making white pig iron, it was not until 1908 that more or less continuous production commenced and has •continued to the present by the American Titanic Iron Company. The whole of the output has been exported to the United States.The ilmenite occurs in lenses •and dyke-like bodies within anorthosite. Production has come chiefly from three deposits: General Electric, Furnace, and East and West Coulombe. During 1951 -52, an extensive diamond drilling programme was carded out under the direction of the writer to test the Furnace and the East and West Coulombe deposits (Figures 2 and 3), which form part of the property of St. Lawrence Iron and Titanium Mines, Limited. The average tenor of the orebodies encountered in the course of the drilling was 38.60 per cent TiO2 and, in addition to these high-grade •bodies, there was found a very considerable tonnage of lower grade ore."

Jan 1, 1953

Iron control and iron residue management and disposal are significant issues in all zinc production processes. This paper briefly reviews the most important primary zinc production routes and discusses the challenges posed by iron control in each of them. The technologies and strategies that have proven successful in controlling and managing iron are discussed. SNC-Lavalin's experience in designing and commissioning zinc plants provides a unique perspective from which to review this aspect of zinc production.

Jan 1, 2006

By Floyd B. Bowen

Pumping methods are used, almost exclusively, to transport materials in the mining, beneficiation and chemical processing of phosphate rock in the Florida phosphate pebble field. Matrix pumping systems capable of pumping 15,000 g.p.m., transporting 15,000 long tons (dry) per hour, are now in use. They utilize 16-by 48 Yz -in. pumps, driven by 1.250-h.p. motors, discharging into pipelines 20 inches .in diameter .and sometimes several miles in length. As an average, it is necessary to pump 3 tons of matrix to the beneficiation plants, and to dispose of 2 tons of sand tailings and clay as waste, in order to produce 1 ton of shipping-grade rock. The washers and flotation plants, where the clay and phosphate and silica particles are separated, require the movement of large volumes of slurries with densities ranging from 2-3 per cent to 45 per cent solids, by weight. Extensive waste disposal systems require the pumping of dilute clay slurries in quantities of up to 50,000 g.p.m.,

Jan 1, 1963

By John N. Ludden, Maurice Rive, Hillar Pintson

"Quelques soixante-dix-sept plutons présents dans la Sous-Province de Pontiac et dans la partie centrale de la Sous-Province de I’Abitibi ont fait I ’objet d’une reconnaissance systématique. Ils ont été regroupes en huit suites plutoniques majeures et trois suites mineures à partir de critères géologiques et petro logiques. Parmi les suites majeures, quatre représentent I' activité intrusive la plus ancienne dans la région. L’une d' entre e/les est représentée par deux complexes anorthosito-gabbroi' ques lites et les trois autres comprennent les orthogneiss dioritiques a leucotonalitiques et les intrusions dons la composition varie de diurétique et granodioritique à leucotonalitique. Leur mise en place peut être pretectonique a syn ou tarditectonique; certains plutons sont synvolcaniques. Quelques data/ions U! Pb effectuées à propos de ces roches donnent des âges s' étalant entre 2 718 et 2 694 MA. Les données géochimiques indiquent la présence des deux lignées magmatiques, tholemique et calcoalcaline bien qu’il n'y ait aucune évidence de relations entre elles dans I' espace et dans le temps. Ces suites magmatiques différentes peuvent provenir soit d’une croute tholemique impliquée dans un processus de subduction soit directement du manteau.Les trois autres suites majeures comprenant des monzodiorites, des granodiorites et des monzonites ainsi que les deux suites mineures comprenant des syenites correspondent à un évènement intrusif plus jeunesse déroulant entre2 694 et2 680 MA. Ces roches sont syn, tarti a post tectoniques et sont enrichies en alcalins, Ba, Sr et terres rares legeres par rapport aux quatre suites précédentes. Leurs caractères chimiques prop res suggèrent qu' e/les proviennent d' une source différente par rapport à celle precedemment citee.La derniere suite plutonique majeure correspond a un monzogranite leucocrate, riche en pegmatite, également syn a tard tectonique, dont I' age n' est pas connu avec précision. ll représente le seul granite ""vrai"" de la région et dérive d’une anatexie soit des meta sédiments soit des granodiorites-tonalites plus anciennes. La troisième suite plutonique mineure correspond a quatre stocks de granodiorite porphyrique qui n’ont pas été étudiés en détail.ABSTRACTSevenly-sevenplutons have been identified in the east-centra/part of the Abitibi Subprovince and adjacent Pontiac Subprovince. These have been subdivided, on the basis of geological and petrological criteria, into eight major and three minor plutonic suite. Four of the major suite, which represent the oldest intrusive activity in the area, range in composition from dioritic-leucotonalitic orthogneisses to diorite-granodiorite/leucotonalite and include two layered anorthosite- gabbro complexes. Their time of emplacement ranges from pretectonic to syn-late-tectonic and some plutons are synvolcanic. U-Pb zircon ages for these rocks range from 2 718 to 2 694 Ma. Geochemical data indicate the presence of both calc-alkaline and tholeiitic magma series for these rocks although there is no evidence time and space relationships between the two. The different magma series also suggest the derivation of these rocks from two sources, either from subduced tholeiitic crust or directly from the mantle. Three major monzodiorite-granodiorite, monzonite, and two minor syenite suites comprise a younger inlrusive event ranging from 2 694 to 2 680 Ma in age. These rocks are syn-, late- to post-tectonica and, compared to the above four plutonic suites, are enriched in alkalis, Ba, Sr and light Rare Earth Elements.Their distinctive geochemistry suggests that these rocks were derived from a different source region than for the older plutonic suites. The remaining major plutonic suite consists of leucocratic, pegmatite-rich, monzogranite-granodiorite. These rocks are also syn- to late-tectonic but their ages are not known with precision. They are the only ""true"" granites in the area and were derived by the partial melting of either older"

Jan 1, 1990

By J. Bruce See

INTRODUCTION This symposium at Cu 2019 has been organised to honour and celebrate the career and achievements of Dr Phillip John Mackey, an internationally recognised expert in the production of non-ferrous metals, especially copper and nickel smelting and refining. Phillip was born in Epping, a suburb of Sydney, New South Wales, Australia on 19 April 1941 and is one of 4 children of Gilbert and Philomena (nee Bartlett) Mackey. After completing Primary School in Epping, he attended Marist Brothers High School in Eastwood, Sydney and graduated in 1957 as the Dux of the School. Phillip’s father, being on the staff of the Sydney Technical College, in Ultimo, Sydney had the opportunity in the early 1950s to meet the late Professor Sir Rupert Myers, Foundation Professor of the School of Metallurgy at the New South Wales University of Technology (later called the University of New South Wales or UNSW). Gilbert Mackey was impressed by the new young Professor of Metallurgy and encouraged his son to study metallurgy - at the time an expanding industry in post-war Australia. EDUCATION AT THE UNIVERSITY OF NEW SOUTH WALES Phillip commenced at UNSW in 1958, graduating with honours in 1963. His undergraduate education and training included a few years of part-time study while working at British Motor Corporation on sheet metal forming of car bodies. At University Phillip developed his talent for teamwork. He was a contributing writer to the University newspaper, Secretary of the UNSW Students’ Union and was active in the UNSW Metallurgical Society and co-editor in 1963 of “Metallurgical Review,” the annual journal of the UNSW Metallurgical Society. His diverse interests and curiosity about the world around him were likely nourished while at University. Upon completing his Bachelor’s degree, Phillip was awarded a Commonwealth of Australia Postgraduate Research Scholarship. He began his PhD in 1964 on the thesis topic “Studies in Heat Transfer between Dispersed Liquid Metals and Gaseous Atmospheres” working under the supervision of then Associate Professor Noel Warner, an outstanding Professor at the University. Professor Warner is now an Emeritus Professor at the University of Birmingham and is internationally respected for his pioneering theoretical and practical work on established and innovative smelting processes.

Jan 1, 2019

By T. W. Wlodek

In this paper the relative merits of shot peening, induction surface hardening, spiral-rolling, and the combination of these surface treatments, are evaluated on the basis of their capacity to increase the fatigue strength of drill steel. The S-N relations for plain car-bon steel (SAE 1080) and Ni-Cr-Mo drill steels in the as-rolled condition were determined previously, using the new Canadian method of testing drill steel introduced at the annual meeting of the Institute in Toronto in 1950 (19). S-N curves have now been determined by this method for these two drill steels in the following conditions: shot-peened and drawn, induction hardened, induction hardened and shot-peened, and spiral-rolled. ( S.R.) . The ratios of the fatigue strengths of these steels after surface treatment, to their fatigue strengths in the as-rolled condition, are compared and the most beneficial treatments are thereby pointed out. The expected range of stresses and their distribution during actual drilling operations are estimated from data available, and the mechanism of failure of drill steel in the as-rolled and surface-treated conditions is analyzed. The magnitude of the surface compression stresses and their effect on ?fatigue strength are discussed.

Jan 1, 1958

By R. G. K. Morrison

By arrangement between the Ontario Mining Association and Messrs. John Taylor & Sons, Mining Engineers, 6 Queen Street Place, London, E.C.4, the writer was engaged for a period of not more than three months to report on the rockburst situation in Ontario mines. This was later amplified, by mutual agreement, to include, at the expense of detail, visits to the larger camps where rockbursts had not occurred, to get a general picture of conditions and to discuss the subject with operators in their respective areas. Scope of Activities Visits were paid to the following properties for the purpose of enquiry and discussion; the underground workings of those mines marked with an asterisk were visited on one or more occasions: KIRKLAND LAKE * Macassa Mines, Limited * Kirkland Lake Gold Mining Co., Ltd. * Teck-Hughes Gold Mines, Limited * Lake Shore Mines, Limited * Wright-Hargreaves Mines, Limited Sylvanite Gold Mines, Limited Toburn Gold Mines, Limited EAST KIRKLAND & LARDER LAKE Upper Canada Mines, Limited Chesterville Larder Lake Gold Mtng Co., Ltd. Kerr-Addison Gold Mines, Limited Omega Gold Mines, Limited PORCUPINE * Hollinger Consolidated Gold Mines, Ltd. * Mcintyre Porcupine Mines, Limited * Dome Mines, Limited * Buffalo Ankerite Gold Mines, Limited Paymaster Consolidated Mines, Limited Preston East Dome Mines, Limited Pamour Porcupine Mines, Limited Broulan Porcupine Mines, Limited Hallnor Mines, Limited Naybob Gold Mines, Limited Delnite Mines, Limited Moneta Porcupine Mines, Limited DeSantis Porcupine Mines, Limited Coniaurum Mines, Limited SUDURY lnternational Nickel Co. of Can., Ltd. * Falconbridge Nickel Mines, Limited LITTLE LONG LAC AREA * Little Long Lac Gold Mines, Limited MacLeod-Cockshutt Gold Mines, Ltd. Hard Rock Gold Mines, Limited Bankfield Consolidated Mines, Limited Magnet Consolidated Mines (1936), Ltd. à PICKLE LAKE AREA * Central Patricia Gold Mines, Limited * Pickle Crow Gold Mines, Limited UCHI LAKE * Uchi Gold Mines, Limited McKENZIE ISLAND AREA Gold Eagle Gold Mines, Limited * McKenzie Red Lake Gold Mines, Ltd. * Cochenour Willans Gold Mines, Limited RED LAKE * Howey Gold Mines, Limited Hasaga Gold Mines, Limited Madson Red Lake Gold Mines, Limited

Jan 1, 1942

By John McEwen, Ian R. Jonasson, David H. Watkinson

"Mine Gallen is a zinc-rich pyritic volcanogenic massive sulphide deposit that occurs in a fault-bounded block of intermediate volcanic rocks. The block is completely surrounded at the present erosion level by the eastern part of the Lac Dufault granodiorite. The volcanic succession includes a massive feldspar porphyry that is probably a subvolcanic intrusion, an andesitic flow unit and lapilli tuffs. The latter are variably sericitized and pyritic, especially in the vicinity of the massive sulphide into which they grade.The ore body is predominantly pyritewith local sphalerite contents as high as 20%; minor chalcopyrite and trace galena are disseminated, but are found mainly along late cleavage. Most ore is a breccia of massive to banded pyrite-sphalerite, veined by massive and complexly banded sulphides. These structures formed by repeated blocky jointing, cracking, sealing, healing and annealing as hydrothermal fluid repeatedly passed through a developing sulphide mound. The deposit is interpreted to have grown on the seafloor in a manner similar to active mounds in the Galapagos rift.RESUME La Mine Gallen exploite un gisement de sulfures massifs volcan géniques comprenant essentiellement de la pyrite riche en zinc. Ce gisement se trouve a /'intérieur d’un bloc de roches volcaniques de caractère dacitique a andésitique, limite par failles et entoure de tout cote par la granodiorite du Lac Dufault. La séquence volcanique comprend des coulées andésitiques et des tufs à lapilli ainsi qu'un porphyre feldspathique massif sub-volcanique. Les tufs sont sericitises et pyritises, tout particulièrement au voisinage des sulfures massifs."

Jan 1, 1990

By Marc Arpin

La Bolivie possède tout pour réussir. Son vaste territoire de plus d'un million de km2 et qui occupe une position stratégique au coeur du continent sud-américain recèle des ressources naturelles (forêts, minéraux, gaz naturel, etc) variées et abondantes. Elle a une frontière avec pas moins de 5 pays dont le géant que constitue le Brésil ainsi qu'avec l'Argentine, l'autre puissance régionale. Pourtant, malgré tous ces atouts, la Bolivie demeure l'un des pays les plus pauvres du continent. Ce paradoxe n'est nulle part mieux reflété que dans le secteur minier. Celui-ci fait face à une situation de crise en dépit d'une tradition minière de plus de quatre siècles et d'un potentiel géologique indiscutable ayant conduit à la découverte et à l'exploitation de fabuleux gisements d'argent et d'étain. Les habitants des districts miniers vivent dans des conditions de pauvreté extrême et les indicateurs de développement humain de ces régions sont parmi les plus bas en Amérique du Sud. La Bolivie réussit difficilement à attirer les compagnies minières alors que, chez les voisins, et particulièrement en Argentine, qui n'a pas de tradition minière, les investissements miniers majeurs affluent. Dans cette conférence, nous chercherons à expliquer les causes de cette situation et proposerons des solutions possibles.

May 1, 2001

By L. Juteau

"""The north coast of the St. Lawrence River will be the scene of an industrial development during the coming decades"". The facts which underlie this statement are the occurrences of iron and titanium ore, the abundance of hydro-power and the availability of deep-water ports in this region. Havre St-Pierre, Sept-Iles, Port Cartier and Baie Corneau already exist as major ports and urban centers. The huge quartz deposit at Baie Comeau will be a decisive contributing factor in the development of a metallurgical plant in this area. Due to its purity, it lends itself, first of all, to the manufacture of glass of different kinds, being comparable to the quartz sands now used by the plate glass and glass container industries in the Montreal area, Moncton, N.B., Trois-Rivieres and - in the future - at Bécancour, Quebec. However, its high quality will also make it possible to use it as one of the main basic materials for the production of silicon carbide and ferrosilicon, and as a flux in metallurgical processes. It is intended, in this report, to offer conclusive proof of the economical importance of this large quartz deposit by presenting the results of the studies made to date."

Jan 1, 1971

By Anton Gronningsater

AT the present time we hear a great deal about organization of labour, collective bargaining, workmen's councils, and company unions; about C.1.0. with its principle of vertical unions and A.F.L., largely based on craft unions; and about provincial and federal laws for protection of labour's right to collective bargaining. What we perhaps hear too little about is corresponding organization of the employers, although it recently is mentioned more frequently. I will only mention W. H. Davis, Chairman of the United States War Labour Board, who has had and is having plenty of experience in this field and has also studied labour conditions in Europe-in Sweden for instance. He has repeatedly expressed the opinion that where employer-employee problems are involved, a thing badly needed in America is organization of employers as well as employees to get some order in the present chaos. With this I agree. I believe a strong organization on one side necessitates a correspondingly strong organization on the other side; that has at least been the experience in the industrialized countries in Europe. I happen to be fairly familiar with conditions in Norway, where they have struggled with these problems for fifty years, and a talk on the history, development, and present state of employer-employee relations in that country might perhaps be of interest as giving a general picture of the development of such relations in the northwestern European countries as a whole. The talk was originally given to the Fourth Year students in Mining and Metallurgy at the University of Toronto. I have changed it somewhat to fit a different audience, but I hope you will make allowances if you now and then are reminded of the school auditorium. I will try to be as objective and factual as possible, but it is probably unavoidable that some of what is said is coloured by personal opinion.

Jan 1, 1943

By T. Schepp, T. Friedrich

"The natural stage of deep mines operation is a closure of unnecessary shafts. It is extremely important to ensure a proper shaft closure to avoid stability loss and the associated damage to surface facilities in the future. For the still active shafts, it can be done by a dedicated shaft closure design, but even then, depending on the shaft closure method, it may be necessary to perform regular shaft inspections. The paper presents a short overview of shaft closure methods and available tools and devices developed in the last time for such shaft inspections. INTRODUCTION The natural stage of deep mines operation, commonly occurring after depletion of the reserves of mined materials, is a closure of unnecessary shafts. All over the world, the number of liquidated shafts grows continuously and the problem of shafts disposal is especially critical for deep shafts. The typical depth of 600 m of currently liquidated shafts in Poland may already be seen as a challenging task. The greater is the challenge of shaft closure in Germany where the last active coal mines for shafts with a depth of up to 1,300 m have been recently closed. It is therefore extremely important to ensure a proper shaft closure to avoid stability loss and the associated damage to surface facilities in the future. For the still active shafts, it can be done by a dedicated shaft closure design, but even then, depending on the shaft closure method, it may be necessary to perform regular shaft inspections. In many cases, it is more important to inspect old, abandoned shafts, where the wall stability or even liner type are not fully known. SHAFT CLOSURE METHODS Abandoning a shaft is a complicated task, as shafts, being the link between the surface and an underground network of workings, disturb hydrogeological and gaseous conditions in the rock mass (Sztelak, 1991). Closure procedures at older mine sites have been carried out in accordance with earlier legislative requirements. For very old shafts (+100 years), it means in many cases only a sealing of the shaft entrances by means of timber or concrete slabs. In the 20th century, the shafts were also closed by means of filling with grainy materials, but even then the retrospective activities at abandoned mine sites were extremely limited and in most cases no further monitoring measures were performed. The possible consequence of an improper shaft closure and lack of monitoring is presented in Figure 1."

Jan 1, 2019

By Doug Russell

Natsource: At a Glance l 160 employees l Global reach ? New York, Washington, Calgary, Ottawa, Toronto, London, Tokyo l Major Environmental Commodity Broker ? Rated as Top GHG Broker (Environmental Finance Magazine Survey, Dec. 2000 & 2001) ? Leading RECs Broker ? Large Broker of SO2, NOx l Large Energy Broker ? One of Highest Volume Gas Brokers ? Major Electricity Broker Overview l International Market l Implementing the Rate-Based Proposal l Assessment and Management of Risk from GHG Emissions Limitations

Nov 1, 2002

By John H. Walsh

"ForewordPart I of this paper, published in the March 1992 issue of the CIM Bulletin, surveyed the probable consequences of a limitation on the emissions of carbon dioxide to the atmosphere for the steel industry. What might be termed the conventional responses to this restriction open to the industry were also surveyed in that section. This section, Part II of the paper, explores a new option - the possibility for the joint production of iron and liquid fuels useful for transportation purposes. In this case, it is shown that it is important to minimize the production of carbon dioxide during the reduction stage to maximize the proportion of the reductant carbon embodied in the fuel. It is also advantageous to conserve hydrogen in the reduction step. In essence, the same carbon fulfills two purposes: it serves as a reductant and fuel for ironmaking and then as a constituent of a liquid fuel. If recovered plastics could be used in ironmaking, the same carbon could serve three useful purposes in turn. The conditions and limitations for the joint use of carbon in such 'cascading' processes are explored below. ABSTRACTIt is becoming increasingly probable that emissions of carbon dioxide from the fossil fuels will have to be reduced to deal with the threat of global warming. This issue is likely to be resolved one way or the other in the period 1995 to 2000 which does not leave much time to develop responsive options. In the intervening period, the policy of the Government of Canada is to stabilize emissions of greenhouse gases at their 1990 level by 2000, by encouraging greater efficiency in the use of energy. Should further reductions prove necessary, economic instruments would probably be employed but these would not be applied before a comprehensive international agreement is reached.There are three main themes in this paper: it is assumed that measures to control carbon dioxide emissions will in fact be necessary by the turn of the century; that there will be a rising need for liquid fuels to supply the world's steadily growing fleet of motor vehicles for many years to come, and that the future niche for Canada's industry in such a carbon-constrained world will be the operation of the energy-intensive industries with efficiency and environmental sensitivity.The steel industry, as a large user of both coal and energy in other forms, would be significantly affected by a need to reduce carbon dioxide emissions. This paper first examines what might be called the conventional responses open to the industry in such a situation and then explores a new possibility for making better use of carbon by the co-production of iron and liquid fuels."

Jan 1, 1992