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By J. K. Whyatt, W. P. Blake, T. J. Williams

A study at the Idaho mine revealed that, despite the apparent randomness of seismic events, common characteristics defined five recurring types. These characteristics included the geological structure that slipped, the first-motion pattern and the location and intensity of damage. Many large events caused little or no damage, and where it did occur it was concentrated at intersections between slipping structures and mine openings. Of 39 events between 1989 and 1994 with local magnitudes of 2.5 or more, 10 were caused by slip on bedding planes in the southern limb of the mine, 6 occurred near the vein along a set of near-vertical faults that form the central shear zone, 8 were strike-slip events on the Southern Control Fault, 4 were by slip on the vein itself and 10 involved strike-slip and/or dip-slip movement along the North Control Fault. Strategies for control of mining-induced seismicity need to consider all five types of event, lest a strategy to reduce one type increases others

Jun 19, 1905

Because of the coincidental location of orebodies and population in Australia, the mineral sands industry has been subjected to numerous land use conflicts, resulting in the sterilisation of strategic ore reserves and a severe downturn of activity in the eastern states. All tiers of government of various political persuasions were responsible for the decisions leading to this sterilisation. As such, it became a community response to intense land use pressure along an attractive and popular coastline. The resultant high public exposure of the industry has placed it in the forefront of developments in rehabilitation technology. In eastern Australia, the industry has operated in a wide range of ecosystems, many with conservation values. Rehabilitation ech- niques have been developed to suit these varied conditions, and much of this technology is now widely adopted throughout the mining industry. Land use considerations in Western Australia are somewhat different to those of the eastern states. Nevertheless, the same basic principles of rehabilitation apply with modification to suit local conditions and land use objectives. The development of rehabilitation in both Eastern and Western Australia is reviewed, and the direction of future trends is indicated.

Jan 1, 1986

By R. Hagiwara, S. Kobayashi, K. Yasuda, T. Nohira, K. Kondo

To establish a process for the electrochemical recovery of rare earth elements from used magnet scraps, the electrochemical formation of RE-Ni alloys in molten NaCl-KCl-RECl3 salt at 973 K was investigated. Cyclic voltammetry and open-circuit potentiometry indicated the formation of several phases of RE-Ni alloys. The formation potential for each RE-Ni alloy phase was determined from the results of scanning electron microscopy and X-ray diffraction of alloy samples prepared by potentiostatic electrolysis of a Ni plate electrode at various potentials. The optimum electrolysis conditions for the separation of Nd, Dy, and Pr are discussed.

Jan 1, 2014

By A. G. Starliper

The Bureau of Mines made laboratory investigations to determine the feasibility of utilizing fine tungsten wires to reinforce a number of nonferrous metals and alloys and a superalloy, S-8l6. The composites of tungsten filament and metals were chosen to attain elevated temperature strength and corrosion resistance. Oriented clean or precoated tungsten wires were incorporated with the other metals by extrusion, swaging, and infiltration casting. Although widely varying characteristics were found in the composites, none were considered satisfactory for high-temperature use, chiefly because of reactions between the matrix metal-tungsten surface. Diffusion, solution, and chemical reactions between matrix and tungsten wires were sufficiently slow for some combinations, such as 15 v/o 8-816, to exhibit increased high-temperature strength for a limited time. A few metals failed to wet or bond to the tungsten surfaces, while a few responded after precoating with a third metal.

Jan 1, 1968

By C. P. Patel

"The Sturgeon Lake Joint Venture volcanic massive sulpide deposit was discovered in 1970. Milling was started by Falconbridge Copper Ltd. at Sturgeon Lake in September 1974. The Sturgeon Lake pit and mill are located 88 kilometers by road northeast of Ignace, Ontario. IgnE1ce is a town of some 2800 people located on the Trans-Canada Highway, 241 kilometers west-northwest of Thunder Bay. The mill is treating an average of 1100 TPD producing separate concentrates of copper, lead and zinc. Initially, difficulties were experienced in achieving accept-able concentrate grades and recoveries but these were eventually overcome. This presentation describes current metallurgical strategy as practiced at the Sturgeon Lake mill.But first, a few words about the type of ore being treated. In geological terms the ore is classified into two main categories. They are the massive sulphides with underlying zones of stringer sulphides as illustrated in Fig. 1. The plan view is shown in Fig. 2. The areas of East-limb and North-limb are as shown. These last two ores have suffered enough alteration to cause problems during treatment. The massive sulphides consist of chalcopyrite, sphalerite, galena, tetrahedrite and small amounts of pyrrhotite among other gangue materials. The stringer ore is comprised of predominantly chalcopyrite intrusions into rhyolite and has lesser amounts of sphalerite and tetrahedrite. At present we are treating a predetermined blend of massive and stringer ores from zones that have been metallurgically tested to ensure compatibility with current treatment procedure in the plant. Ore responding to this treatment is classified as normal ore while the ore proving incompatible is classified as north-limb ore or east-limb ore."

Jan 1, 1980

By understanding the ore breakage characteristics and utilising comminution circuit modelling, the benefits of SAG mill feed size manipulation can be readily assessed. This paper looks at the benefits and problems of total secondary crushing of mill feed and advocates partial secondary crushing as a means of improving grinding efficiency for certain hard ores. Case studies are reviewed for new and existing SAG mill circuits.

Jan 1, 2007

By Robert I. Fujimoto

The work described was conducted to develop standards for the application of wire rope clips on wire rope. These standards include optimum number of clips and clip nut torques for wire rope sizes 1/4 through 2-1/4 inches, when used for forming an eye attachment in wire rope. Wire rope test specimens with clip attachments were load tested on tensile testing machines to determine an effective combination of clip nut torques and number of clips for each size of wire rope to develop efficiencies above 90 percent of the catalog ultimate rope strength.

Jan 1, 1973

By Spruille Braden

My attendance at this seventy-fifth Anniversary banquet of the A I M E is for me a homecoming, It means renewing associations with old friends, breathing again 'the invigorating mining atmosphere in which I was born and reared, and being among those who remember with affection and esteem the man from whom I inherited a name so intimately linked to-the mining profession Tonight, like a prodigal son strayed from mining into the far countries of diplomacy, I return, to eat and be merry over the fatted calf on this pleasurable occasion , While there is no riotous living in modern diplomacy, you are no doubt convinced that neither did I suffer a mighty famine in those far lands When I entered the Foreign Service, a few mining friends, viewing diplomats as sartorial perfectionists, or "striped pantsers" preoccupied with the art of cookie pushing, no doubt thought me a lost soul Conversely, some of my new colleagues at first looked upon me captiously and later as a reformed character, because they believed all miners to be rough customers, attired in muddy boots and given to direct action and equally direct or even explosive speech In point of fact, these two professions have much in common I do not have in mind the parallel cynicisms that "a miner is a liar with a hole in the ground" and "a diplomat a man sent abroad to lie for his country " I do

Jan 1, 1947

By L. G. Austin, P. T. Luckie

The Bond Work Index has been used for many years to estimate the power requirement of a material with known work index. The index is determined by a completely empirical test and no logical base for its use has been formulated. However, consideration of grinding as a unit operation which can be mathematically treated offers the prospect of considerably more accurate design and mill power estimation when sufficient data on large-scale mills becomes available. The interrelation of the Bond type with the unit operation approach is discussed.

Jan 1, 1973

By Thomas F. Torries, George H. K. Schenck

Crushed and broken stone is used directly in construction as an aggregate and accounts for about half the value and two-fifths of the quantity of natural aggregates consumed in the United States. Sand and gravel provide most of the balance of aggregates except for some lightweight materials such as pumice and expanded shale. Conditions necessary for production of crushed stone from a deposit are : 1) Quality-should pass rigid specifications for strength and durability. 2) Cost-low average total delivered cost. Construction aggregates are hard, essentially inert materials suitable for being formed into a stable mass either (1) by the addition of cementing or binding materials that produce a concrete or (2) by compaction or by natural weight to produce a road base or foundation. Aggregates usually provide about 80 to 100% of the material volume of the construction masses in which they are used. The construction industry utilizes as aggregates about 70% of all crushed stone produced in the United States according to statistics provided by the U.S. Bureau of Mines (USBM) , [Table 1], using definitions as shown below. Nonconstruction uses of crushed stone, [Table 2], are included elsewhere in Industrial Minerals and Rocks because such uses require the special physical or chemical characteristics which are discussed in those chapters.

Jan 1, 1975

As we are all well aware, the demand for coal is increasing very rapidly. This makes the coal industry one of great opportunity for both the miner and the-supplier. Up until the middle 1960's, the price of coal had been one of the most stable of all commodities for the proceeding fifty years. In somewhat oversimplified terms this was because the inflationary tendencies had been offset by improved mine techniques and more efficient, more productive, and more reliable equipment; but, in the last seven years the price of coal has doubled. It is not the intent of this paper to discuss the many reasons for this price increase, but to show how the cost of hauling coal can be sharply decreased with a new truck concept. Not long ago a mining executive stated that all haulage trucks now available are basically the same. They look the same; they cost about the same; they have the same engine, power train, and tires; and, they have about the same operating cost. Truck size has increased which has reduced the number of drivers, but the purchase price and maintenance and repair costs have increased proportionally. Pits must be widened and loading shovels enlarged, out, all this has not reduced the cost of moving coal. Another executive said that he saw no advantage in buying new trucks because his people now know how to maintain and operate the ones they presently have. They have all the right spare parts along with a good maintenance program. Most replaceable parts of the trucks now in operation have been replaced and improved at least once and the trucks are now running better than when they were new. Besides, the trucks are no pretty well written off.

Jan 1, 1972

By Gupta R. C

Syria has about 500 million ton deposit of minerals having 34 per cent iron content with alumina and silica as major impurities. Efforts were made to see the feasibility of concentration by four different methods involving washing, high intensity magnetic separation, reduction roasting and magnetic separation and acid leaching technique. It was observed that the reduction roasting with magnetic separation yields a concentrate with high iron (62.3 per cent) content without requiring water which is a scarce raw material in the region. The paper concludes that the detailed study may be made following this route to optimise the process Parameters.

Jan 1, 1999

By A T. Spathis

Corrections are given for “A three parameter rock fragmentation distribution” by A.T. Spathis (Measurement and Analysis of Blast Fragmentation, Workshop hosted by 10th International Symposium on Rock Fragmentation by Blasting, New Delhi, India, November 25-29, 2012 pp. 73-86). Typographical errors in two equations for the uniformity index in the two versions of the original and modified Kuz-Ram model are corrected. It is noted that the modified equation in the original published paper of Cunningham also had the same typographical error. A corrected plot of the dependence of the uniformity index versus the burden to diameter ratio is given. These corrections do not affect the rest of the original published paper.

Jan 1, 2013

By G. C. Weatherly, D. S. Wilkinson, A. M. Limarga

Competition between stress generation and relaxation mechanisms during the oxidation process has been observed. However, the nature of the intrinsic growth stress in thermally grown scales is not well understood. In this talk, we will propose a conceptual model to calculate the intrinsic growth stress based on the analysis of stress-driven diffusional process of oxygen ions along the oxide grain boundary. The calculated stress, which is considered to originate from the constrained lateral expansion of the oxide, is in agreement with a range of experimental observations.

Jan 1, 2004

By M. H. Lampen

The SILAG Material Tracking System MTS monitors and controls the complete material flow throughout the plant - and even companywide. The customized system developed by Siemens especially for bulk material handling applications enables companies to track bulk material from the mine to the harbor, to the steel mill or to the power plant. All relevant material data is available at every single step of the material’s journey. SILAG is an open, scalable system based on Windows NT / 2000. Using standard interfaces of Windows NT, like API, ODBC, SQL and socket technology, the system is very flexible and can easily be tailored to meet different requirements. SILAG can be used as a stand-alone solution or - if complete plant control and visualization is required - as a component of a fully integrated automation system with the Win CC HMI system and the PCS7 process control. In contrast to conventional material tracking systems, SILAG offers many advantages. - The Material Tracking System is an object oriented, online to the process, linked system. All changes in the plant during operation e.g. selecting another conveyor route, start and stop etc. will be automatically detected and will influence the calculation. - The systems is able to split and blend material (quantity and quality).Measurements of tonnage, volume or quality analysis can be linked online to the system. Each movement of material is monitored by the system and leads to online recalculations of the images and databases. - All material data is based on 3D-stockpile images, which are calculated by an internal mathematical model based on quantity and quality information. - If a laser scanner is available on a stockyard machine it can be taken to update the profile directly from the piles. - Efficient control and report functions are available on each, free selectable point of the total plant.

Sep 1, 2001

By J. G. Mieczaniec

"A key element for a successful mining operation is the grinding circuit. It must be reliable, maintainable and must perform to or above design capacities for 95% of the time. Once chosen and installed major modifications are either prohibitive or very expensive. The selection of mills and drive system is probably the single most important decision made within the concentrator complex.Economic studies revealed that the optimum expansion for Lornex was a 68070 increase in plant throughput. This indicated that the new mill would have to be larger than the existing 32-foot mills.The Lornex ore has a wide range of hardness which has a great influence on mill throughput (Table 1). To smooth out the fluctuations, a blending program ha s always been in effect at the mine, coupled with ball charge control for the primary mills. As can be appreciated, an optimum balance is difficult to achieve. A sudden change to so ft ore with a high ball charge puts the mill into jeopardy with a constant speed drive.The blending philosophy would continue after the expansion, but with the addition o f a second primary crusher, it was envisaged to have the new mill process harder ore to maintain production targets. In theory, the new mill would have a proportionally larger ball charge than the existing mills.This scheme makes the new mill vulnerable for processing so ft ore for a fixed speed mill. Thus, variable speed seemed an attractive option.In early 1979 prominent mill manufacturers were invited to submit proposals for the new mill. Fixed and variable speed mills were to be considered with mill size ranging from 32-foot to 36-foot diameter. The proposals were to include the drive, ball charge, % critical speed, couplings, gears, etc. - the complete package. The recommendations were variable with most manufacturers submitting several alternatives. Recommended mill speed varied from 68% to 78% critical. The concept of variable speed was becoming more attractive, Lornex ultimately decided on a twin DC motor drive system for a 34-foot diameter mill.After start-up it was discovered that best throughput occurred at 78% mill critical speed or top speed of the drive motors. The motor speed range was adjusted upward from 186 to 200 rpm. Today the mills operate at 79% critical or a motor speed o f 193.5 rpm.Clearly the selection of the variable speed mill allowed the flexibility to optimize throughput."

Jan 1, 1985

By J. Winlock

To have been chosen by you to give the Howe Memorial Lecture is the greatest honor I have ever had and I should like to have you know that I appreciate it deeply. Many years ago I had the privilege and the pleasure of working with Professor Howe in the private laboratory which he had established in his home at Bedford Hills, New York. Without doubt he was one of the world's greatest metallurgists and so you can imagine what a difficult task it has been for me to live up to his teachings. Every morning Professor Howe would outline the work he wanted done and the recollections of those conferences are clear to me to this day. Sometimes he would ask me to ride in his automobile and the chauffeur had full instructions to go no more than fifteen miles an hour. If he did so, Professor Howe was sure to rap upon the man's shoulder with his cane. I assure you, however, Professor Howe's thinking was not at that rate. His homely advice, his patience and his perfect control of the English language still impress me. Many times I heard him dictate a complicated paper on metallurgy and never find it necessary to change a single word. There are no better words to describe the character of Professor Howe, in my opinion, than those used by Professor Sauveur when he presented the John Fritz Medal to him in 1917: "Lover of justice and humanity Public servant and public benefactor, Master of the English Language, Loyal and devoted friend, Untiring and unselfish worker in an important field of science." I hope you will bear with me with the same patience and understanding which he used to give to me. The peculiar behavior of steel at the yield point has long been known and has been the subject of much research, both in this country and abroad.',' Many theories, including some of mine and my colleagues, have been suggested, but none of them, in our opinion, fully explains to our satisfaction why the phenomena occur. Of particular importance has been the work of Nadai,3 Siebel and Pomp,' Sachs and Fiek,5 Rawdon,0 Kenyon and Burns,' Gensamer," Gensamer and Meh1,0 Davenport and Bain,'" Fell," Deutler,12 Brinkman,13 MacGregor,14 Hollomon,15 Cot-trell,16 and Palm." The question of what is occurring during this singular behavior is not only of interest from an academic point of view, but is of great practical importance for at least two reasons: 1—The highly localized plastic flow which occurs during the deep drawing of light-gage steel gives rise to surface markings which seriously mar its appearance, Fig. 1. If the forces causing the deformation are primarily tensile forces, these surface markings occur as depressions in the surface. Whereas, if the forces causing the deformation are primarily compressive, irregular lines of elevations occur. These surface markings are known as Luder's lines, Hartmann lines, the Piobert affect, and, in the shop, as "stretcher strains." 2—The steel is in the most suitable condition for deep drawing after the yield point phenomena have been removed. When this is done, the steel may be deep drawn more easily and to a greater extent.' It should be mentioned that steel is not the only metal which shows this peculiar behavior at the yield point. Stretcher strains occur, also, during the deformation of some copper-nickel-zinc alloys." The purpose of this paper is not an attempt to describe what causes the steel to behave in this peculiar manner, but an attempt: l—to describe what is taking place at the yield point; and 2—to show the influence of the rate of deformation on the tensile properties of some plain carbon steels. As is well-known, there are two methods of deforming a metal in tension: 1—by actually hanging an increasing amount of dead weight on the metal; or 2—by deforming the metal at some given rate or rates by means of oil pressure cylinders, screws, etc. With the first method, the load is always present and, clearly, no drop in load can ever occur while the steel is deforming. With the second method, the registered load is the resistance of the steel to the deformation being imposed upon it. The second method is the one most widely used, and is the one referred to throughout this paper. In order to describe clearly what is occurring at the yield point in steel, it will help, I believe, if a description is first given of what occurs when alumi-

Jan 1, 1954

By N. Djilali

Many of the transport phenomena encountered in proton exchange membrane fuel cells occur intrinsically at the microscale level. Physically representative models that fully account for the salient physico-chemical and transport processes in PEM fuel cells are necessary to achieve truly predictive models that can be used with confidence to: (i) gain a better understanding of in-situ processes and couplings, (ii) explore new concepts, and (iii) support design and optimization. The development of more general, rationally based macroscale models requires use of knowledge on the microscale level to provide guidance, and to determine the required parameters and coefficients (model "constants"). In this paper we present a new membrane transport model, the binary friction membrane model (BFM2), recently developed to account for coupled protonic and water transport in polymer membranes. This general model is based on rational and physical consideration, removes several of the limitations of the empirical models used to date, and is formulated for all purfluoro-sulfonic acid membranes. The use of the BFM2 in a fuel cell model is illustrated highlighting significant performance predictions compared to existing empirical model. The second part of the paper addresses the fundamentals of two-phase transport in hydrophobic gad diffusion media. Computational and experimental visualizations resolving the microscale dynamics of water transport between the fibres of a GDL are presented, revealing transport mechanisms that are, contrary to assumptions used to date, dominated by fingering and channeling.

Jan 1, 2005

By W. A. Lang

"I.-IntroductionAn attempt bas been made in this paper to provide a basis for appraisal of the future of the coal briquetting industry in Alberta by outlining the processes used for briquetting various ranks of coal, by specifying the requirements of a briquetted fuel, by indicating .the status of the industry in the United States, by giving developments in Western Canada, by assessing costs of processing, and by discussing briquetting researches in progress. Much of .the detail bas been omitted since this might mask, rather than reveal, the more important phases of the problem. Reference will be made when possible to published articles where many of the details can be obtained.It should be stated at the outset that, in the writer’s opinion, there are three possible developments in Alberta as regards briquetting: (a) an expansion of the briquetting of the fines of • non-coking and coking coals of semi-anthracite, and of low and medium volatile bituminous rank; (b) the processing of the fines of high-volatile C bituminous coals; and (c) the upgrading of the lower rank high-moisture sub-bituminous coals. Details of the chemical and physical properties of these coals can be obtained in publications of the Research Council of Alberta (1, 2), and of the Fuel Research Station, Bureau of Mines, Ottawa (3).Semi-anthracite and low and medium volatile bituminons coals occur in the mountain areas of Alberta, where, during the upthrust of the Rocky mountains, the coal beds served as the sliding surface. This resulted in the coals being; crushed and consequently they contain a h1gh percentage of fines. In some cases they are high in mineral matter and require to be cleaned before being processed. However, the cleaning of fine coal is both difficult and costly. Both the amount of fines present in the mine-run coal and the amount of mineral matter associated with the coal have increased through the introduction of mechanized mining and through the recovery of coal by stripping operations."

Jan 1, 1950

The No. 2 Ore-shaft, at Mount Isa Mines Limited, involving the use of boreholes as ropeways for the upper portion thereof, constitutes, we believe, a unique feature in hoisting installations. The boreholes were sunk from the surface to a depth of 390 ft., thus eliminating the necessity of erecting the hoist at an underground location or construction of the shaft for this distance. Fig. 1, a diagrammatic cross-section through the shaft, shows the complete installation from the surface down to the first loading station below No. 7 haulage level.During the latter part of 1936, conditions encountered in sinking the Main Ore shaft made it impracticable and uneconomical to continue deepening it to serve haulage levels below the present No. 5-level. Plans were therefore made for an interior shaft, to serve new lower levels, that terminated above No. 5-level so that ore hoisted could be drawn off on this level and transported to the Main Ore shaft for final conveyance to the mill crude ore bin.Referring again to Fig. 1, it is apparent that the section above No. 4-level, if opened out to full shaft size, would be inoperative and would serve no useful purpose except, possibly, as a ventilation duct. Original plans therefore did not include continuation of the shaft above No. 4-level. Excavation of a hoist room upon No. 5-level; erection of sheave wheels just below No. 4-level, and a long inclined ropeway leading from the hoist to the sheaves, were incorporated in the general layout. Work on the lower sectionof the shaft had started when the idea of locating the hoist...

Jan 1, 1939