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By L. M. Southwick

"The history of extractive metallurgy is replete with examples of commercializing new processing technologies. The successes are widely reported, but failures seldom are. This is unfortunate, for usually we can learn more specifics on how to succeed in technology development by studying and thoroughly understanding their failures. Frequently one encounters a red herring that caused the whole effort to fail. A thorough and objective due diligence up front would have identified those red herrings and prevented the pursuit of a bad idea and the resulting destruction of capital. Due diligent analyzes performed before construction of three such bad ideas will be discussed. One is an EAF dust process, which pursued the red herrings of a poor understanding of the business, a naïve view of past experience, and false confidence in the technology. Another will examine the effort to commercialize a new pressure copper leach process that followed the red herrings of inadequate testing of the raw material, application of processing conditions that were inherently unsafe, and an improper assessment of the inherent advantages of past developments. The last is an alternative iron-making process, where the red herrings were incomplete and superficial assessment of prior pilot plant and demonstration plant tests, an assumption that the commercialization model of “build it and we will make it run” was viable, and a technology whose technical fatal flaws had already been identified. Unfortunately, capital destruction often also closes the window to more intelligent pursuit of technology development. TECHNOLOGY COMMERCIALIZATIONThe development and commercialization of new technology is a vital part of keeping industry profitable, able to deal with new sorts of feed stocks and current with economic, product, operational and environmental requirements. This is a difficult task in the best of times, and can be compounded when the developers become enamored of a particularly favorable characteristic of the project or of the product. These “red herrings” divert project focus away from the arduous path to success and, in the end, result in project failure."

Jan 1, 2012

By D. Campbell Mackenzie

THIS paper is submitted primarily to put on record the results of a number of experiments carried out at the Wingdam mine of Consolidated Gold Alluvials of B.C., Ltd., with the object of establishing a reliable method of concentration of 'wash' and a maximum recovery of gold from the concentrate. It will be generally admitted that, during the last two decades, a tremendous amount of research work has been carried out, both by private companies and Government departments, with a view to improving the technique of the recovery of gold .from quartz veins or lodes. So thorough have been these investigations that milling practice at a modern quartz gold mine is almost an exact science, carried out with meticulous accuracy. In placer mining, on the other hand, very little departure from old traditional methods can be noted, with the exception perhaps of the more modern gold dredges. This may be due to the fact that the concentration of placer gravels, up to a certain point, is comparatively easy. Only a simple equipment of sluice box and riffies seems necessary where the gold is coarse and the gravel free from clay. In the early days of placer mining, when claims were rich and fairly 5hallow, nobody worried very much about fine gold; and, if clay was present, an enlarged dump box was constructed in which the gravel was subjected to a rather desultory puddling. That large quantities of gold are lost in normal placer practice is generally admitted. Some 26 years ago, I had inspectorial charge of many bucket dredges on the Ovens river, in Australia. Occasionally it was necessary for a dredge to work through its own tailing to reach a new section, and almost without exception enough gold was recovered from these tailings to defray the total cost of moving the dredge. Since those days, the technique of gold recovery in dredging has been considerably improved and it is still receiving close attention. Outside of dredge mining, most placer operations, deep or otherwise, are as they were-notorious gold losers, paying little attention to the recovery of fine gold and taking an absurd amount of time over each clean-up. In the Cariboo district of British Columbia, the alluvial gold is usual y associated with varying quantities of black sand (magnetic) and grey sand (non-magnetic); and it can be taken as axiomatic that, if you save all the black sand and grey sand, you save practically all the gold. It is on this hypothesis that we have carried out our research work and brought our recovery system up to its present highly satisfactory standard.

Jan 1, 1937

By C. Jay Hodgson, P. J. MacGeehan

"Of the 135 current or past-producing 'gold-only' mines in the Superior Province of the Canadian Shield which have produced more than 100,000 tons of ore, the 33 mines which have produced one million ounces or more of gold have accounted for over 84o/o of the total production of 137 million ounces. The published literature on these 33 deposits was reviewed in order to determine the geological setting of the mineralization on a regional (mining camp) and local (mine) scale. The dominant rock types underlying the mining camps are mafic, variolitic, tholeiitic volcanic rocks with a significant ultramafic (komatiitic) component, and clastic and/ or exhalative sedimentary rocks. Felsic volcanic rocks are generally subordinate. Most mining camps are located at or near the top of the mafic-ultramafic sequence, and generally there is a major sedimentary-volcanic contact present which may be 1) a stratigraphic superposition of volcanic and sedimentary units, 2) a rapid, along-strike gradation from dominantly volcanic to dominantly sedimentary units due to facies change, or to the formation of structurally controlled sedimentary basins during volcanism, or 3) frequently (at 40o/o of the camps) a juxtaposition of sedimentary and volcanic sequences across a major fault zone or 'break', which in many instances may represent a reactivated, syn-volcanic basin-margin fault.In contrast to the regional setting, on a local or mine scale over 90o/o of the 33 mines contain felsic intrusions and/ or extrusions within mine workings. The felsic rocks may be quartzbearing (commonly quartz-feldspar porphyries) or dominantly quartz-free (commonly feldspar porphyry syenites or monzonites), and appear to have been emplaced in two different depth-zone environments: an epizonal intrusive environment, and a volcanic vent environment. Although the distinction between epizonal intrusive and volcanic intrusive-extrusive rocks is uncertain in many deposits, the two are tentatively separated on the basis of the grain size of the rock matrix (medium to coarse grained vs aphanitic to fine grained), homogeneity (multi-phased and/ or compositionally zoned vs compositionally homogeneous), and the shape and relationship to stratigraphy of the igneous body (circular or oval in cross section, and cutting the stratigraphy at a low angle vs lenticular and either stratiform or cutting the stratigraphy at a high angle). In addition, felsic intrusions of the volcanic environment commonly grade into tuffs or breccias of extrusive origin, whereas epizonal intrusions do not.Stratiform ore zones of possible exhalative sedimentary origin appear to be confined to deposits in which volcanic felsic rocks are present, and are absent from deposits in which only epizonal felsic intrusions are present. Pervasive carbonate- rich alteration, commonly in roughly stratabound zones of regional extent, and carbonate-rich chemical sedimentary rocks are present in over three-quarters of the deposits containing quartz-bearing felsic volcanic rocks, but are much less common in deposits with quartz-free felsic volcanic rocks. The host sequences of epizonal felsic intrusions which are quartzfree are more commonly sedimentary than those of quartz-bearing epizonal felsic intrusions.Quartz, carbonate minerals, arsenopyrite, scheelite, tourmaline and Cr-muscovite ('juchsite') are the most common mineralogical associates of gold. Arsenopyrite is essentially restricted to the volcanic environment, occurring in about twothirds of the deposits with quartz-bearing felsic volcanic rocks and less than half of the deposits with quartz-free volcanic rocks. Tourmaline, on the other hand, is almost ubiquitous in deposits associated with epizonal intrusions and also occurs in about two-thirds of the deposits associated with quartz-bearing felsic volcanic rocks, but in only one of the eight deposits associated with quartz-free felsic volcanic rocks. Scheelite is essentially restricted to ores of quartz-rich fel"

Jan 1, 1982

By W. D. Haley

The report of the Forestry Committee, presented to the recent Imperial Conference at London, is discouraging in its view of the future of timber resources and supplies. From a review of the forestry situation throughout the world, there is every likelihood that, thirty years from this, a shortage of the soft-woods will be severely felt. In the United States, only about one-third of the present forest area contains virgin timber. This will be cleared at the rate of five and a half million acres a year, so that in twenty-five years it will be about all gone. Canada has only about 27 per cent of her original forests left, and her virgin soft-wood will last but another half century. At the present time, the value of her lumber products is over $300,000,000 annually. During the summers of 1909 and 1910, the Government of Nova Scotia caused an examination to be made of the forest conditions in this Province. The reconnaissance, which was under the direction of Professor B. E. Fernow, of Toronto, involved an examination of the various soils, the rate of growth of the wood, and a general survey of the forest area. The importance to the Province of conserving its forest resources was clearly shown, and a number of recommendations were made, which; however, were never acted upon.

Jan 1, 1927

By Charles Camsell

If it were necessary to preface a discussion of the mineral position of the Empire by justifying one's interest in that subject, there are two points that at once suggest themselves by way of vindication. Tremendous Growth of MINERAL Consumption The first of these points has to do with the general question of the world's mineral consumption. Most thinking persons appreciate in a more or less vague way the vital rôle that has been, and is being, played by mineral products in building up the material side of our modern civilization. But, apart from that casual and almost subconscious appreciation, very few have any precise knowledge of the extent to which the growth and the operation of our vast present-day industrial structure has been made possible by, and only by, a tremendous increase in the consumption of mineral products of all kinds. The increasing use of minerals confronts us today at almost every turn. It does not matter in what direction we look-at the expansion and the change in transportation facilities, in the air as well as on land and on sea; at the increasing mechanization, not only in factory and mill but even in our domestic life; or at the constantly widening use of machinery for all phases of farm production-everywhere we meet the same phenomena of rapidly growing uses of equipment produced mainly from minerals. Without resorting to any tiresome statistics, a few figures may suffice to indicate with what enormous strides the world's mineral consumption has been advancing. The figures for recent years may be open to objection on the plea that, ever since the outbreak of the world war, conditions have hardly been sufficiently normal to give us trustworthy data-we have been living under extremes either of depression or of abnormal stimulation. During the last decade before the war, however, from 1903 to 1913, the world was moving along in a quietly prosperous manner; and we have figures, or at least reasonably reliable estimates, as to the growth in mineral consumption during that decade.

Jan 1, 1932

By S Grönstrand, C. Perez, A. B. Yañez, F. Coddou, P. Morales, H. Elgueta

"The TankCell® 300 forced air flotation cell designed and built by Outotec, with active volume of over 300 m3, was installed at Codelco’s Chuquicamata concentrator in September 2008. After that, a program was conducted, where the new cell was tested against the plant’s existing flotation cells of type TankCell® 160, with an active volume of over 160 cubic meters.Testing program was exhaustive and detailed. Grade-recovery curves for each setup were reported, along with recoveries by particle size. Secondly, operational characteristics like air feed and froth height setpoints, and power consumption are compared side-by-side. As the third topic, gas dispersion characterization included velocity mapping, holdup, bubble size and bubble surface area flux operating range. The fourth area of interest was the retention time distribution (RTD) of the 300 and 160 m3 cells in comparison. A detailed campaign using radioactive tracer tests was conducted to clarify this.All of the investigations mentioned above are reported in separate papers for more detail. The aim of this paper is to collect the key findings, and present them in real terms, always referring to operability and metallurgy of the cells. It is destined for people designing new plants and to those improving and expanding existing ones. The most frequently heard question is: will the new large cells operate at same efficiency as the smaller ones. In short, the answer is: NO. They operate at improved efficiency!INTRODUCTIONIn the last two decades of minerals processing, there have been three dominant trends of development in the flotation technology: equipment scale-up, cell characterization and circuit modeling. Equipment scale-up has been rapid in the past two decades. In the year 1990, the largest flotation cell in use was 50 cubic meters of size. This year, 300 cubic meters is the largest installed cell. Characterization of flotation equipment and circuits is a very popular subject nowadays and has helped many operations to improve their recoveries through better control strategies, for example by using optimized air feed and level control profiles (Gorain, 2005), (Doucet, Gomez, Finch, 2006), or through better maintenance (Coleman, Urtubia, Alexander, 2006). Characterization work is closely linked to circuit modeling. The aim is to produce sufficient amount of data to allow reliable model building. These models are then used to design new circuits and to improve existing ones. So in summary, these three lines of development have slightly different aims – from capital and operational cost to performance optimization. Ultimately, they converge in the same end result – maximizing the profitability of the operation. Following chapters will summarize the extensive test work and scientific studies at Codelco Chuquicamata. The aim was to compare a TankCell® 300 cell, with nominal volume of 300 m3, against two TankCell® 160 machines, with 160 m3 volume in each. The work should yield answers to questions: does the larger cell produce similar results – is the scale-up successful?"

Jan 1, 2010

By J. E. Dutrizac

"The end of an era in zinc metallurgy took place on July 31, 1976 when the horizontal retort furnaces of the National Zinc Company in Bartlesville, Oklahoma were permanently shut down (1) . For more than a century, horizontal retorting had been the most common method of producing zinc in the United States; it was a thriving industry in many parts of that country, especially in the natural gas belts of Oklahoma and Texas. With the Bartlesville closure, yet another metallurgical process has become an object of historical interest for North American metallurgists. Although shrouded in controversy, the origins of zinc metallurgy seem to date back at least 2000 years. Pyrometallurgical methods with carbon reductants are capable of producing zinc from oxidic zinc ores, but only above the boiling point of the metal. Although slow cooling results in re-oxidation of the zinc vapour by air or carbon monoxide, quenching yields liquid zinc; some form of rapid cooling, either accidental or intentional, was likely used by ancient metallurgists to liquify the metal. Zinc metal found in Athenian objects of the Roman era was likely of accidental origin. The Romans employed brass extensively for coins and ornaments(2) , and this was intentionally produced by the calamine process whereby oxidic zinc ores were added to molten copper under strongly reducing conditions. Zinc appears to have been known in China and India as early as 1000-1300 A.D., and was probably smelted commercially in those countries from the 14th century. Although the early metallurgical procedures were probably inefficient, they were able to produce zinc metal in significant amounts. The large heaps of zinc residues with clay retorts bear testimony to an early smelting industry of impressive magnitude. It is estimated that the heaps at Zawar, India alone represent the extraction of 100 000 tons of metallic zinc(2) In the 1730s the smelting of oxidic zinc ores was developed in England using a vertical retort method. In 1788 a British patent was granted for making zinc from zinc blends (ZnS) by roasting the ore in a coalfired reverberatory furnace, mixing the calcine with charcoal and smelting the mixture with suitable zinc condensation. The English process was very energy intensive, however, and early in the 19th century the Belgians developed a horizontal retort process for the reductiondistillation of zinc that was more fuel efficient. This technique was gradually developed into what came to be known as the Belgian process, the forerunner of the ""modern"" horizontal retort furnace."

Jan 1, 1999

By N. Schreithofer

The deposition of octadecylamine (ODA) at the KCI crystal/NaCI-KCI brine interface was investigated using atomic force microscopy (AFM). The AFM images of freshly cleaved KCI specimens immersed in KCI-NaCI saturated brine at room temperature reveal disappearance with time of the atomic steps and formation of cubic NaC1 crystals. These crystals were found to form when the specimen was withdrawn from the saturated solution. Depending on the way of contacting the specimens with the octadecylamine dispersion, the AFM images show huge differences in the deposition patterns of ODA on KCI crystals. Adequate dispersion was found to help the formation of quite even ODA coverage. The coverage was several monolayers thicker when air/brine/solid contact took place, suggesting that in the potash flotation the collector is likely to be carried to the solid surfaces by air bubbles. The presence of methyl-isobutyl carbinol (M IBC) enhanced the dispersion of ODA in brine, thus helping the spreading of the surfactant on the KCI crystal surface.

Jan 1, 2006

By F. A. Auld

"Traditionally deep shaft sinking from the ground surface was carried out using drill and blast methods. Although large diameter blind shaft drilling has been carried out successfully on numerous occasions previously, including as early as 1852 in Germany (Auld, 1995), little attempt has been made until more recently to mechanise the shaft sinking excavation process using down-the-hole machines. This paper reviews the development of deep shaft sinking machines from the early 1970’s up to the present day. INTRODUCTION Mechanical excavation methods can significantly improve excavation performance, in order to access natural resources faster, and labour safety is increased compared to drill and blast operations. However, shaft sinking machines need to be capable of accommodating all the basic requirements for deep shaft sinking, namely: 1. Excavation and muck removal 2. Ground stability control 3. Groundwater ingress control 4. Temporary lining installation 5. Permanent lining installation and watertight sealing 6. Ventilation 7. Secondary means of egress for personnel In addition, how the machine operates in the shaft is an important factor, either slung on ropes from a surface headgear or on its own in the bottom of the shaft. An all-embracing machine which can deal with all of the above conditions is impossible but many of these requirements can be incorporated into a single machine. Deep shaft sinking also differs greatly from normal tunnel construction which employs the use of either a roadheader arm installed within a shield or a full-face tunnelling machine for excavation. Hydrostatic pressure and ground stability problems increase with depth, whereas in tunnelling the depth is normally relatively shallow and the aforementioned factors remain approximately constant along the tunnel length. DEEP SHAFT SINKING MACHINES All the shaft sinking carried out previously in the UK was by the traditional method of drill and blast. Elsewhere, in other parts of the world, attempts have been made to mechanise the process."

Jan 1, 2019

By F. R. Archibald

Introduction It is the purpose of this paper to review the subject of roasting as preparation of refractory gold ores and concentrates for cyanidation, with particular reference to operations at the mill of Beattie Gold Mines (Que.), Ltd., Duparquet, Quebec. Two earlier papers relating to the Beattie roasting operations are cited as background to the ? present discussion, and more general reference is made to other publications relating? to geology and metallurgy at Beattie. The Beattie roasting plant was built in 1937 as an addition to the existing flotation and cyanidation plant to permit complete processing of the ore at the mine property. Previously, the flotation concentrate had been cyanided, yielding 70 per cent of the gold values, followed by re-flotation of a concentrate from the cyanide residue. This re-floated residue was shipped to a smelter for recovery of gold values unavailable from direct cyanidation. The roasting plant itself is of interest through application in its design of multiple-hearth roasters and a Cottrell plant for separate recovery of dust and arsenic. In the laboratory and plant studies that accompanied development of the plant into a dependable and efficient working unit have been found principles and ideas applicable to other roasting 'problems. Before enlarging on these aspects relating particularly to the Beattie problems and plant, brief consideration is given to roasting in general.

Jan 1, 1949

By A. E. Hilder

Introductory The following pages present the results of field investigations, laboratory and commercial tests, drilling, surveying, and preliminary development of the refractory clays which have been discovered recently in the township of Kipling, at the foot of Long rapids on the west side of the Mattagami river about 57 miles north of Kapuskasing and approximately 7 miles north of Smoky Falls, the terminus of the privately owned railway operated by the Spruce Falls Power and Paper Company, Kapuskasing (see Figure 1). Investigations on the clays of northern Ontario have been carried on over a period of seven years by officers of the Ontario Department of Mines, and I am indebted to the information published by that Department in reports by W. S. Dyer and A. R. Crozier, as well as?by Professor R. J. Montgomery, of the Ceramic Department, University of Toronto. It was, in large measure, the data given in the 37th, 38th, and 42nd Annual Reports of the Ontario Department of Mines that led me to make a personal investigation of the Mattagami River clays, with the result that we now have a commercial undertaking that will develop eventually into an industry of considerable importance in supplying the central manufacturing districts of Canada with refractories that heretofore have been largely imported from the United States. An extract from the 42nd Annual Report of the Department, Part III, 1933, page 75, reads as follows: "As for the refractory clay, the deposits are undoubtedly very large, but what is urgently needed is a deposit near the railway under sufficiently shallow overburden for recovery by stripping'. Having previously made an investigation of the clays adjacent to the Temiskaming and Northern Ontario railway, and these clays proving unsuitable, I turned my attention to the outcrops of refractory clays on the Mattagami river, first reported by Keele in 1919. This area offered possibilities within the economically permissible distance from rail transportation.

Jan 1, 1935

Keeping the sediment on the mine site and out of the water course is essential from the regulatory, environmental and sustainability perspectives. Regulation of this aspect of mining is embedded in environmental legislation and government receiving water quality standards, and government control has apparently been considered to be the most appropriate method to define mine site discharge standards and the environmental implications of sediment in downstream watercourses. A literature search for guidelines for the site specific design and operation of sediment ponds treating mine site runoff to remove total suspended solids, turbidity and flocculant-induced toxicity, revealed little information on the mining industry?s and government?s roles in defining the ?how to achieve? related to sediment pond design. Is there a need or reason for an industry-driven leadership to clearly define the ?how to? keep the sediment on the mine site and out of the water course? Currently, this issue is addressed in Canada by a federal mining regulation for metal mines which specifies discharge quality for sediment. This paper focuses on the method used in British Columbia, Canada, to regulate and provide a scientific methodology to control the discharge of sediment from mine sites. Management plans relative to this topic are discussed and are considered to have value from the exploration, construction, operation and the onset of closure phases. In addition, the balance and linkage between the erosion control management plan and the sediment pond management plan are discussed in terms of how they may be designed to complement each other to lower the risk of exceeding discharge and receiving water quality standards. If there were an industry-driven standard, or guidance document relative to addressing sediment release, it would benefit mining companies by eliminating the repetitive analysis of this topic for each new mine, mine expansion, and mine modification; also, government may often replace certain aspects of permitting with a regulation, if there is a government/industry established standard defining Best Achievable Technology (e.g. the Canadian Metal Mining Effluent Regulations).

Aug 1, 2013

By F. L. Thompson

MAN has been using lubricants of one type or another for at least four thousand years, and probably for a much longer period. We have learned from the inner wall of the tomb of Tehuti-Hetep, on which is a decoration illustrating the method of moving a great stone statue, that as early as 1650 B.C. lubricants were used to facilitate the movement of heavy loads. The Egyptians had available nearly every animal oil and fat, as well as at least thirteen vegetable oils, of our time, all used for food products and in the arts. Examination of the deposit on the axle of a chariot from an Egyptian tomb of 1400 B.C. showed it to consist of animal fat, quartz, sand, iron, and compounds of aluminium and lime-indicating a manufactured lime-soap grease made with lime-soap and possibly tallow. This would not be a bad lubricant for the axles of chariots which had to travel over sandy soil in hot weather. As to the method of grease application, it is remarkable that, from the time wheels were first used in the far distant past up to the present day, no one has ever thought it necessary to design a seal to keep the lubricant in and the dirt out. While time certainly marches on, we have today, in waggons throughout the world, exactly the same form of lubrication as was used in the earliest chariots. From the early days of the chariot until shortly before 1800 A.D. (when the steam engine was introduced), the main heavy equipment required for mining purposes, for machines of war, etc., was made of wood. The bearings were rough, but usually they had metal in the lower half. Light machinery was made of bronze, brass, or iron. Large clearances and poor alignment, plus the fact that speeds were much below present-day demands, combined to provide conditions that were quite satisfactorily met by the lubricants available. These were often produced locally by the machine operator. In northern countries, lard oil, prepared from the fat of hogs, was the universal lubricant employed in machine shop, as a belt and leather dressing, and for cutting operations. Sperm oils were used for light machinery, whereas beef and mutton tallow were more generally employed for the largest bearings. For the early steam cylinders, a slug of heated beef tallow was injected wherever the cylinders gruntingly complained of a lack of lubricant. Southern countries, however, resorted to the use of vegetable oils-olive, cocoanut, etc.

Jan 1, 1940

By Alfred W. G. Wilson

In this paper is presented a review of the changes that have taken place in certain Canadian non-metallic mineral industries since 1909. The fifteen-year period 1909 to 1923, inclusive, has been selected for two reasons. In the first place, statistical treatment of the subject under review has been nearly uniform throughout the period. In the second place, this decade and a half is itself further subdivisible into three well marked quinquennial periods, the middle one covering the period of the great war when industrial conditions were greatly disturbed. It then becomes possible to institute certain comparisons between equal periods before and after the war disturbances. The items selected for inclusion in this review are certain of the more important members of that class of minerals usually grouped together under the heading of non-metallics. They are all minerals of which Canada is known to possess important resources, and which are indispensable to many of our greatest manufacturing industries.

Jan 1, 1925

By R. D. Merer

The production of low- and medium-Btu gas from coal provides a more economic source of energy for most industrial users than pipeline-quality coal gas (SNG), although the latter has received more publicity. The paper reviews existing and advanced methods of coal gasification, with particular emphasis on the production of low- and medium Btu gas for industrial and utility use. Some of the ways in which coal gasification can be integrated into power cycles and industrial plant energy balances are discussed.

Jan 1, 1978

By H. Marquis

The present paper consists of a survey of the literature on the problems of abrasion and wear of metals and materials by suspended matter. This problem is a very general one in industry, and is especially notice-able in the operation of cyclones and other types of dust collectors. The problem of abrasive dust in corrosive gas environments, such as commonly encountered in metallurgical industries, is particularly severe. Very little work has been done in the study of this type of abrasive wear, especially at high temperatures. However, a general review is presented here of all the work published on related subjects, such as that involving sand erosion in turbines and water wheels and the effect of temperature on friction wear. Topics in this paper include: blasting wear by sand, quartz, limestone, silicon carbide and other refractory particles; methods of investigation; effects of velocity, temperature and *Canadian Armament Research and Development Establishment, Valcarter, P.Q. angle of attack; correlation between indentation hardness, scratch hard-ness and resistance to abrasion; the effect of protective coatings; resistance of various metals; etc.

Jan 1, 1962

By Paul W. Billwiller

Introduction In 1937, the Britannia Mining and Smelting Company, Limited, was carrying on an extensive exploratory diamond-drilling programme. Most of this drilling was done on the 4100 level, the lowest working level in the mine. One of the exploratory diamond-drill holes, at approximately 12,500 feet from the portal of the tunnel, encountered heavily mineralized stringers of chalcopyrite and sphalerite in silicified grey schist. The mineralization was encountered just to the hanging-wall of the green mottled schist at a point 350 feet south of the 4100 tunnel. To delimit this new orebody, drifts and cross-cuts were driven on 3500, 3800, and 4100 levels to the hanging-wall in the area of the projected mineralization. On the 3500 level, the top of the mineralized zone was encountered. The zone was thoroughly explored by drifting and diamond drilling. The mineralization, however, was not sufficiently concentrated to be of commercial grade. On the 3800 level, the zone was found to consist of disconnected stringers of chalcopyrite and pyrite. Drifting was continued to the west and a long lens-shaped area of grey schist containing fairly heavy stringers of chalcopyrite was delimited. This lens later proved to be very close to the top of the commercial mineralization of the No. 8 orebody. On the 4100 level, a diagonal cross-cut was driven to the footwall of the downward projection of the mineralized zone. Diamond-drill holes from this cross-cut indicated a zone of heavy mineralization. A drift was driven off the cross-cut parallel to the zone and some distance to the footwall of it. Further diamond drilling disclosed a mineralized zone approximately 300 feet long and 35 feet wide containing sphalerite, chalcopyrite, and pyrite. The foregoing development work indicated a fairly large lens of mineralization of sufficient concentration to be classed as ore between the 4100 and 3800 levels. To explore this mineralization at depth, long diamond drill holes, dipping at minus 57° and minus 80°, were planned from some point to the hanging-wall of the orebody. The 4100 level was not suitable for small development headings, due to wider gauge track and larger cars than on the levels above. Therefore, a raise was driven from the diagonal cross-cut on the 4100 level to a point some 70 feet above and just inside the footwall of the orebody. From the top of the raise, drifts were expanded east and west to delimit the ore zone. In addition, a long cross-cut was driven 350 feet to the hanging-wall, and drifts were opened east and west from the end of the cross-cut to provide diamond-drill stations for the exploration of the orebody at depth.

Jan 1, 1946

By E. Zucker

In this paper, as in the 1960 CIM paper of the same name, s1gmf1cant new developments in electrical-mechanical mining equipment are briefly described. These include static thyristor-supplied D.C. drives for mine hoists, load-haul-dump systems, process controls with small and medium-size computers, and several other new items of equipment and Concepts. All the new hardware descriptions are given in the context of over-all process integration. This means the actual mechanical linking together of two or more processes and the preliminary step in the development of production-line mining.

Jan 1, 1969

By G. M. Carr-Harris

"THE SUBJECT of permanent molding has received a great deal of attention in the technical press as illustrated by the many excellent articles in the bibliography which follows. In general, this covers the period 1940-1958 and is merely representative of what is available. Numbers in •brackets refer to items in the bibliography.It may be desirable at the outset to give a few definitions covering those terms directly related to this subject. The following is a definition of permanent-mold casting as given by J. W. Meier in a paper, ""The Non-Ferrous Metals and Alloys"", read before the Ottawa Valley Chapt.er of the American Society for Metals:""Permanent Mold Casting is used where a large number of castings of the same part are required and higher mechanical properties, greater density and closer tolerances are essential. Since metallic mold s are very expensive, the number of castings must be sufficient to, defray, at least partially, the added expense. Molds are usually made from a good quality cast iron, 1but other mold materials, such as the aluminum and copper alloys, graphite, ceramics, etc., are being used in certain cases. Important factors in permanent mold casting are the mold temperature; the proper mold dressing; and, as in all other casting methods, the mold geometry, that is to say, the design of spruces, gates, risers and vents""."

Jan 1, 1960

By Earle J. Klohn

"The design, construction and operation of tailings dams is rapidly becoming a major consideration for most new mining developments, as well as for many existing operations. In North America, under pressure from public opinion, various government agencies have in recent years enacted legislation covering the design, construction and operation of tailings dams. In British Columbia, comprehensive legislation has been passed during the past year (1971). All of these new regulations may be placed into two broad categories: regulations concerning the safety of the dam and appurtenant structures, and regulations concerning the prevention of pollution. Both types of regulation affect the design of the tailings dam facilities. Consequently, they must be considered jointly by the designer. A good tailings dam design must satisfy the basic requirements of safety, pollution control, storage capacity and economy. To achieve this, 'the design must be based on a thorough understanding of both the geotechnical problems involved and the requirements of the mining development. Obviously, this requires close cooperation between the designing geotechnical engineers and the mining operators. This paper outlines the major engineering factors that should be considered in the investigation, design, construct ion and operation of tailings dams. Basic methods of tailings dam construction are reviewed and the advantages and disadvantages of each briefly discussed. Comparisons are made between the design and construction of conventional water supply dams and tailings dams. Examples are presented of some of the problems that may arise during construction and operation of a tailings dam. The paper also explains the need for basic instrumentation of tailings dams and for carrying out simple field tests and measurements during construction and operation. Of prime importance is the downstream monitoring of surface and subsurface seepage flows. These observations are invaluable where contamination of surface and/or subsurface water may become a contentious issue at some future date. Each tailings dam design must be based on a study of the particular requirements of that project. To make a proper evaluation, adequate data must be available concerning a large number of items•, including such things as: topography, hydrology, geology, subsoil properties, seismicity, government regulations, fineness of mill grind, mill water balance, availability of suitable construction materials, volume of water to be stored behind starter dam, downstream development or liability, and many others. The large number of variables involved in such an evaluation often result in the designer considering two or more alternative designs. Selection of the final design, which is usually based on detailed cost analyses of the alternatives, must be made in close consultation with the owner."

Jan 1, 1972