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By G. J. Birnie

Introduction The preparation of the following paper has been undertaken in the belief that a description of the development methods and equipment used at Lake Shore, at the present time, will prove of general ? interest. Working depths of nearly a mile and a half in shaft sinking and of more than one mile for stoping operations have imposed problems not encountered at shallower horizons. Among the problems contributing to the difficulty of mining at extreme depths might be mentioned: Rock pressures Ventilation Hoisting Shorter work period at the face Geological considerations In the main, the effects of these factors add to the difficulty of mining at depth, but it is not entirely true to say that each must necessarily become more pronounced as mining operations proceed to greater depths. Corrective measures may, in some cases, retard the effect and in others may even relieve some of the difficulty. It is proposed here to discuss these features in the light of the experience at Lake Shore, and to present, in some detail, the current practice in shaft sinking and in driving ore and waste passes, raises, drifts and cross-cuts.

Jan 1, 1950

By M. Vallée

Several reviews of mineral project performance in the past 35 years indicate a pattern of occasional, but recurrent, mining project failures due to shortcomings in geological information and estimation, mineral processing and metallurgical testing, feasibility study objectives and requirements, and project start-up methods. A commitment to quality assurance and continuous improvement methods and to obtaining “ENOUGH DATA, OF APPROPRIATE QUALITY” is essential. Recent international and Canadian proposals for mineral resource and ore reserve definitions have taken a nonprescriptive stance that will undermine the formulation of requirements, guidelines and industry standards for efficient deposit delineation and estimation, and for the determination of project feasibility. To help reduce problems, every feasibility study supporting a mine development and production decision should be based on objectives and methods adequate to reach completion targets similar to the bankers’, as a good business target for a profitable project. In a resource/reserve system, the use of reserve should be restricted to a project that meets required technical, economic and legal feasibility requirements for successful project implementation, and the definitions of these categories should provide explicit limits. Current shortcomings will limit the ability of the Qualified Person to provide “adequate professional practice,” fulfill his/her professional responsibilities to his employer or client and provide adequate information to the investing public. We must take advantage of present opportunities for Setting New Standards for the new Millennium.

Jan 1, 2000

By Pizhi Zhao, Yingdong Li, Hailong Cao, Yingjuan Feng

"Three types of anodic films (unsealed, hot water sealed and agent sealed) were prepared to study the effects of anodizing pores structure on the adhesive bonding performance of AA5754 automotive sheets. The morphology of the anodic films was examined by using scanning electron microscope (SEM) and the composition was examined by glow discharge optical emission spectroscopy (GDOES). The adhesive bonding strength and durability in corrosive environment were investigated by using single lap shear test and salt spray corrosion test (SST), respectively. The results showed that the pores structure could significantly influence the adhesive bonding performance. The unsealed sample showed porous structure and provided high bonding strength, however, the durability was poor in corrosive environment. The hot water sealed sample showed fine and loose hydrated alumin a structure on the surface and provided high durability in corrosive environment, but the bonding strength was low. In contrast, the agent sealed sample provided both high bonding strength and durability in corrosive environment.INTRODUCTIONAdhesively bonded aluminum joints by using adhesives have been widely used for the realization of lightweight design in industrial applications like automotive and aerospace industry[1, 2]. Durable bonds which are capable of taking structural loads can be created due to a careful consideration of the way in which the joint is formed, the type of adhesive and the appropriate treatment of the adherend surfaces prior to bonding[3-6]. Experiences demonstrate that the surface treatment is the most critical step which could not be disregarded, since it is essential to achieve long-term service capability [7].In structural applications, a bonded assembly is expected to maintain a significant load and may be combined with exposure to harsh environmental conditions in its service life. For this purpose, the pretreatment for structural bonding of aluminum alloy must provide not only strong tensile strength and durability but also good corrosion resistance. Chromic acid anodizing (CAA) process provides an anodized layer which has good corrosion resistance while also exhibiting useful adhesion characteristics as well as lacquer coating retaining characteristics[8].However, the use of Cr (VI) is unadvised from a health and environmental point of view since it is toxic and carcinogenic, and this process is gradually limited even prohibited. Boeing's phosphoric acid anodizing(PAA) process provides a more open pore structure allowing penetration of high molecular primers/adhesives[8]and PAA process is the most widely used pre-surface treatment suitable for adhesive bonding between aluminum alloy components. Rahimi et al. demonstrated that nanostructure can be produced by PAA process and is affected by the time of pretreatment and anodizing parameters [9]. Xu et al.investigated the influence of surface energy and roughness on adhesive bonding through PAAprocess and provided improved adhesion performance under certain anodizing parameter[10]. However, PAA process is normally not recommended for a major concern of deterioration of the mechanical performance of the joints as a result of exposure to a wet and corrosive environment. Sulfuric acid anodizing(SAA)process, recently, has been widely used for corrosion protection and good base coating for the adhesion of lacquers in aerospace manufacturing[11]. The good performance is explained by properties such as the porous morphology and high adsorptive power of the oxide film, the chemical and electrical inertness of the anodized layer. Moreover, modified sulfuric acid could also used for adhesive bonding. Lunder et al. found that anodizing in hot sulfuric acid is promising as a simple, very rapid and environmentally friendly pre-treatment for adhesive bonding[12].Saeedikhani et al. studied the process of phosphoric/boric/sulfuric acids anodizing and found it was is a promising pre-treatment for adhesive bon"

Jan 1, 2018

By E. A. Rychkun

"For the last 700years of recorded economic history, man has been subjected to alternating inflationary and deflationary patterns. Through this period of time, a severe deflationary pattern has developed approximately every 55 years, creating 12recordable occurrences. Through the last two centuries, this severe deflationary phenomenon has come to be known as a depression. As these depressions have repeated themselves regularly, they are cyclic. This in turn leads to the question of whether the 13th cycle will also repeat itself in the form of a depression. As this cycle is now 51 years old, we must consider the possibility at about 1984.In analyzing a 700-year record of consumer prices in Southern England, the 55-year cycle appears to vary in shape and intensity. This varying phenomenon is due to the effect of longer cycles upon which each one ""rides "". Because each cycle effectively rides on the next largest, which in turn rides on the next largest and so on, the combined measured effect of all cycles together at any point in time is always unique. This means that anyone cycle can never repeat itself in an exact identical manner. The combined effect therefore is what we observe in the form of prices and, as cycles interact, variations in deflation are produced . The ""science"" of economics attempts to quantify and develop theory on situations which are never identical and hence can be conservatively classified as a useless predictive tool.This means that more unconventional approaches may be required to predict our economic future. In looking at previous depression cycles, it is possible to recognize similarities in human behaviour patterns and hence the resulting economic movements. These behaviour patterns create major events or influencing factors which set the scene for a major deflationary condition. The way in which these factors occur, however, is not predictable. As more and more of these similar events are identified in each cycle, we can increase our confidence on the probability of the last event occurring (a depression). By also unravelling the set of larger cycles, we can determine the potential combined effect at any point in the future.This paper presents a system of cycles ranging from 800 years to 3 years which appear to operate in our economic system. By so doing, a long-term projection into the next century can be made. Finally, the paper deals with the main controlling similarities within the depression cycle, to show that a comparison with our current cycle implies that a major deflationary collapse in the mid 1980's is virtualy inevitable."

Jan 1, 1980

By E. Fritz

This paper reviews the history, developments and 10 milestones of the oxygen steelmaking processes, with a special focus on conventional autothermic converters, high-speed converters with a blowing rate up to 5 m3n/t min and allothermic converters with coal addition, post combustion and the possibility to increase the scrap rate up to 50%. Related operating results are introduced. A new process route, which is based on hot metal and chromium ore, is outlined. The cost advantage for the production of 304 stainless steel grade is higher than 100 USS/t. The synthesis of EAF and oxygen converter steelmaking, a comparison of decarburization rates, refining combustion burners for optimized oxygen-management in EAF and an example for a large advanced EAF are outlined. Possibilities of flexible steelmaking and the growth and outlook of worldwide oxygen steelmaking are described.

Jan 1, 2004

By G. M. Scamans

In the past ten years there has been considerable penetration of aluminum automotive body sheet (ABS) into automotive structures. The exponential increase in demand is resulting in major investments in heat treatment and finishing capacity across the globe. Line speed and tonnage throughput is limited by the continuous heat treatment (CHT) floater furnace rather than the cleaning and pretreatment section where electrolytic treatments that offer higher line speeds should come into favour and roll coating of pretreatment should predominate. The capacity limiting surface texturing pass will either be eliminated or moved to the finishing line or a dedicated mill. The key to making aluminum both embedded carbon and cost competitive with steel for more and more affordable classes of vehicles lies in recycling of both prompt scrap and, in the longer term, end of life vehicle scrap. For the first time scrap separation technology is available that can compete effectively with hand sorting and can sort aluminum shredded vehicle scrap into wrought and cast alloys and then into individual alloy groups. The challenge is to use more end of life scrap in alloy formulation whilst at the same time extending the property range in terms of both strength and formability.

Jan 1, 2015

By G. M. Scamans

In the past ten years there has been considerable penetration of aluminum automotive body sheet (ABS) into automotive structures. The exponential increase in demand is resulting in major investments in heat treatment and finishing capacity across the globe. Line speed and tonnage throughput is limited by the continuous heat treatment (CHT) floater furnace rather than the cleaning and pretreatment section where electrolytic treatments that offer higher line speeds should come into favour and roll coating of pretreatment should predominate. The capacity limiting surface texturing pass will either be eliminated or moved to the finishing line or a dedicated mill. The key to making aluminum both embedded carbon and cost competitive with steel for more and more affordable classes of vehicles lies in recycling of both prompt scrap and, in the longer term, end of life vehicle scrap. For the first time scrap separation technology is available that can compete effectively with hand sorting and can sort aluminum shredded vehicle scrap into wrought and cast alloys and then into individual alloy groups. The challenge is to use more end of life scrap in alloy formulation whilst at the same time extending the property range in terms of both strength and formability.

Jan 1, 2015

By G. B. Langford

UOCK bursts are a phenomenon about which insufficient is known. This l.~ statement has a twofold meaning. In the first place, far too many people, both inside and outside of the mining industry, are woefully ignorant of the whole subject, and secondly, as those who are face to face with the problem in the mines realize, our knowledge of rock bursts is inadequate. The first group embraces the general public, who have never been enlightened on the subject, and a great many geologists and engineers who have never shown more than a curiosity about it. Such technical men do not realize what a vital problem it is to our mining industries. They are usually thankful that bursting ground is not their problem, and leave it to those unfortunate enough to run into it. From such men one often hears the pious opinion that if proper mining methods were used there would be no problem. It is hoped that this paper will give these people a different viewpoint. Those in the second group deserve much credit for what they have done and are doing. They are fighting a large and difficult problem. In the pages that follow, I have tried to give a bird's-eye view of that problem, and suggest new ways in which it may be attacked.

Jan 1, 1941

By E. C. W. Perryman

BEFORE describing the methods used for fabricating uranium into various shapes and sizes it is necessary to illustrate briefly the unusual conditions under which uranium has to operate when used as a fuel element in a reactor. During reactor operation, for every fission that occurs two atoms of intensely radioactive fission products are produced together with two or three neutrons. The neutrons that are ejected possess several m.e.v. of energy and when one of them strikes an atomic nucleus, that atom acquires up to 105 e.v. of kinetic energy. This is large enough to displace the atom from its lattice position and send it shooting through the crystal, displacing other atoms out of their lattice positions. The net result is that a large number of vacancies and interstitial atoms are formed within the crystal lattice which sometimes have profound effects on the physical and mechanical properties of the material in question.

Jan 1, 1957

By B. W. Williams

The crack propagation behaviour of Zr-2.5Nb pressure tube material was studied through comparison of the measured behaviour with the predicted response from finite element analysis. Three-dimensional finite element simulations of compact tension specimens were performed using the crack tip opening angle as a fracture criterion to allow for crack propagation. To obtain reasonable agreement with the measured behaviour, it was important to capture both the anisotropic plastic deformation behaviour of the Zr-2.5Nb material through use of the Hill-48 yield criterion and damage due to void growth, nucleation, and coalescence through the use of a Gurson-based constitutive model in the simulations.

Jan 1, 2010

By James H. Cobbs

Blind boring of shafts is becoming an increasingly important part of shaft sinking. Blind-bored shafts have reached diameters of 25 It in Europe and 16-1/2 ft in the United States. Much of the technology developed for blind boring has evolved from the technology of drilling wells for oil and gas production. Blind boring offers economic advantage in a number of situations where conventional shaft sinking either is extremely difficult or very expensive by virtue of large-capacity aquifers which must be penetrated, unstable ground or where very rapid sinking is required. In sedimentary rocks, blind boring is cost competitive with conventional sinking, in diameters of about 12 ft or less. Blind boring is not competitive with raise boring where conditions are favourable for raise boring. Blind boring does, however, offer greater flexibility than raise boring and can be performed in situations where raise boring is inefficient or impossible. Combination machinery has been developed to perform both blind boring and raise boring, so that the machine can be used effectively in situations where only the near-surface portions of the shaft are unfavourable for raise boring. Development work is being supported by the United States Bureau of Mines for blind boring equipment capable of boring shafts up to 30 feet in diameter.

Jan 1, 1979

By H. W. Smith, C. L. Lewis

"A process control computer has been installed in the Lake Dufault concentrator to: (a) control the on-stream X-ray analyzer and convert chart readings to elemental percentages, (b) calculate the flow rates required for the most important flotation reagents, using the amount of material entering the process, the analyses and the slurry pH, and (c) set the reagent feeder to these flow rates automatically. Although this project was largely experimental, to gain knowledge and experience in flotation process control, the objectives have been met and fully automatic computer control is now the normal mode of mill operation.This paper describes project planning and defines the system with respect to both control design and functional design. System operation -as seen by the mill operator -is detailed. Implementation of the system is described and the system is discussed in terms of its success, economic justification and future plans."

Jan 1, 1969

By J. Peterson, D. D. Tannant, J. Todd

"A review of blast designs and improved blasting practices at the EkatiTM diamond mine is presented along with the results of three blast-monitoring experiments. Blast monitoring was undertaken to investigate blast damage mechanisms in the mine’s well jointed rock mass. Rock mass damage caused by production, pre-shear and wall control blasts was measured. EkatiTM uses 270 mm holes for production blasting, and 165 mm holes loaded with a decoupled charge for pre-shearing. The production blasts are loaded with bulk emulsion/ANFO blends. The mine plan involves using 30 m double benches. A 30 m high pre-shear is drilled and blasted prior to the production blasting that is done with sequential 15 m benches. This paper summarizes the monitoring equipment and data gathered to date. IntroductionThe EkatiTM diamond mine is located about 300 km northeast of Yellowknife, Northwest Territories, Canada. The mine is a joint venture of BHP Diamonds Inc. (80%) and geologists Charles Fipke and Stewart Blusson (10% each). The EkatiTM mine is Canada’s first diamond mine and BHP is the operator. The mine is accessed by air and by a winter ice road.The first kimberlite pipe mined at EkatiTM is known as the Panda pipe. The Panda open pit mine will have a total depth of 315 m (Fig. 1), a width of about 600 m, and a 50° overall slope. Initial ore production is 9000 tonnes per day.This paper summarizes the pre-strip blasting and the evolution of the production and wall control blast designs from 1997 to 2000. The initial blast designs and the rationale behind subsequent changes that took place are presented along with the techniques currently in use.The paper also briefly presents an experiment done to measure the rock mass response to blasting. Three blasts were instrumented with geophones, gas pressure sensors and time domain reflectometry cables. A brief summary of the instrumentation and data gathered is included."

Jan 1, 2001

Once applied, EarthZyme reduces the tendency for a road to exhibit common maintenance issues: wash-boarding, rutting, heaving, potholing and dust.

Aug 1, 2013

By Krishna Parameswaran

"This paper discusses energy use and conservation in the primary copper industry and illustrates eco-efficiency considerations, using select examples of practices at ASARCO LLC, an integrated primary copper producer and others in the industry that promote eco-efficiency. The World Council for Sustainable Business Development first publicized the concept of eco-efficiency at the Rio Earth Summit in 1992. Eco-efficiency is a management concept linking environmental and economic performance and is aimed at generating added value for a business through, among other things, increased resource and energy conservation and reduced environmental impacts throughout the life cycle of the product or service. This concept differs from sustainable development in that focus is only on economic and environmental factors and does not include social considerations. In the metal mining and processing context, this added value can be realized by implementing practices that promote conservation of water and mineral resources, conservation of energy, minimization of waste, reduced emissions and effluents and increased recycling. The examples from the primary copper industry used to illustrate eco-efficiency considerations include: water and energy conservation in mineral processing, adoption of flash and bath smelting processes, emission reduction and process improvement associated with fire-refining, implementation of green chemistry in electrorefining, promoting product stewardship initiatives and fostering renewable energy project on disturbed mined lands.INTRODUCTION ASARCO LLC (Asarco) was organized in 1899 as the American Smelting And Refining Company. Originally a consolidation of several lead-silver smelting companies, it evolved over the years into an integrated producer of primary non-ferrous metals, including copper, lead and zinc and associated co-products. Grupo México, S.A.B. de C.V acquired Asarco in 1999. Today, Asarco is a vertically integrated producer of primary refined copper and associated co-products such as gold, silver, molybdenum, selenium and tellurium. Asarco operates three open-pit mines and mills, two leach, solvent extraction-electrowinning (SX-EW) plants and a copper smelter in Arizona and a copper refinery in Texas."

Jan 1, 2017

By S. Nafisi

Permanent mould casting may be regarded as a near net shape manufacturing process where simple to very complex shaped engineering components are fabricated with high degree of precision in a metallic mould, In this group, High Pressure Die Casting (HPDC), have attracted more attention because of its production rate, where both liquid and semisolid metals (SSM) can be cast with high degree of precision and versatility. The SEED process, Swirled Enthalpy Equilibration Device, the new process for semi solid metals slurry production route, consists of two steps: The initial step involves extracting specified amount of heat from the molten metal to generate liquid-solid slurry, i.e, mushy structure, followed by drainage of remaining liquid to produce a compact free standing feedstock for rheocasting operation. In this paper, microstructural evolution during the process and some initial casting results of automotive components an also reported.

Jan 1, 2005

By J. L. Jambor, J. E. Dutrizac, J. B. O'Reilly

The present-day metallurgical community is quite familiar with the use of jarosites [MFe3(S04)2(0H)6 where M = K, Na, NH4, Ag, 1/2Pb, etc.] as a means of controlling iron, alkalis and sulphate in hydrometallurgical circuits. This modern precipitation technology has found an increasingly widespread application in the zinc industry111 and is gradually also being extended into the hydrometallurgical processing of copper and cobalt121 . The chief advantage of jarosite precipitation is that the iron precipitate settles and filters well, and gives low losses of divalent metals in the washed residue. Although this jarosite precipitation technology was developed only within the past twenty years, man's involvement with jarosites extends back to antiquity, and jarosites have played an important role as a source of silver in several ancient metallurgical centres. In the early days of this century, argentojarosite was an important local source of silver at the Tintic Standard mine, Dividend, Utah, where over 200 000 oz of silver were recovered from highgrade natural jarosite over a three-month period 131 . At the Matagente mine in Peru, pockets of argentiferous plumbojarosite up to 40 m thick were mined and processed by the Indians prior to the arrival of the Spaniards14-51 . In Cyprus there are vast jarosite deposits associated with the ancient mining sitesl51 , but exploitation of these jarosites has been insignificant because of their low silver values. The most extensive mining of silver-bearing jarosite, and certainly the oldest documented instance of such jarosite exploitation, was in the vast pre-Roman workings at Rio Tinto, Spain. This mine, the greatest single miningmetallurgical site currently known from the ancient world and also the oldest site of more or less continuous metal production, has witnessed many metallurgical firsts. Aside from the initial processing of jarositic ores for their silver values, the development of large-scale hydrometallurgy also seems to have occurred at Rio Tinto. As early as 1737, copper was recovered by cementation on scrap iron from the mine waters at Rio Tintol51 . Large-scale heap leaching of calcined ore commenced with the British operations in 1876 and, by 1900, raw pyrite was heap leached to recover associated copper values161 .

Jan 1, 1999

By Ross Gallinger

In 1997 a group of Canadian mining companies met to review the Mine Environment Neutral Drainage (MEND) program and to consider future activities. They concluded (i) that Canadian industry and NRCan should fund a small secretariat in Ottawa to support technology transfer in Canada and (ii) that it was important for industry to continue the momentum of MEND on an international scale. The need for INAP (International Network for Acid Prevention) was strongly endorsed by company, university, consultant and government experts from Australia, Canada and the U.S. who were convened in Vancouver in February 1998. The initial focus was the development of a solid knowledge base covering the collective experience of INAP's members to promote the dissemination of successful practices, the identification of knowledge gaps and the formulation of effective research proposals. The sharing of information on past successes and failures alone was viewed as sufficient justification for the formation of INAP. INAP was officially launched in October 1998, and is now an effective, industry based initiative to globally coordinate research and development in the management of sulfide mine waste. Significant improvements in the management of sulfidic mine materials through knowledge sharing, research and development of technology by INAP will reduce liability associated with acid drainage. This paper will explore the international efforts and activities of INAP.

May 1, 2002

By Donald E. Archibald, Gerald A. Allcott

"Noranda's Heath Steele Mine is located 35 miles north of Newcastle in northern New Brunswick. Blasthole open stoping with partial delayed filling is the major mining method in use. The selection of stope and pillar dimensions to ensure mine stability was originally subjective. This paper describes the progress made in attempting to rationalize design.One major feature is the fracture pattern. The main orebody now being mined, the B zone, has undergone five periods of folding and each period of folding developed a family of fracture planes which are axial planar to that particular fold pattern.The other major features considered are the calculated increase in stress due to mining and depth and its relationship to measured strain. Experience has shown that ground problems affecting production have usually originated in rib pillars. Field observations of ground deterioration and multi-wire extensometer measurements of strain are tabulated together chronologically for each pillar.A factor representing stress and a common plane of weakness are identified. Graphical analysis is used to determine the effect of the plane of weakness on a typical stress/strain curve and provides a base for the design of pillars."

Jan 1, 1981

This paper focuses on the dissolution of various Manganese based compact additions into liquid Magnesium. The experimental procedure employed cylindrical compacts with various Manganese compositions. The various temperatures of the additions and the Magnesium bath were measured simultaneously during the immersion of the additions into Magnesium bath. The exothermicity level of these additions during their dissolution into liquid Magnesium was determined. The relation of the exothermicity level with the dissolution kinetics was also examined. In addition, SEM and EDX work was conducted for additions, which were withdrawn from the Magnesium bath. Finally, the recovery of these additions was estimated by taking samples from the Magnesium bath and conducting ICP analyses.

Jan 1, 2006