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By R. R. Sayers

The increasing use of hydrogen fluoride (annual consumption now exceeds 500,000 pounds (1)4/) directly and its occurrence as a byproduct of the utilization of fluorine compounds in the mineral industries, especially in metallurgical processes and in the refining of petroleum products, has aroused interest in its toxicity, and a brief review of the literature, with special reference to the hazard of poisoning in the mineral industries, seems to be opportune. Recently, residents in the vicinity of aluminum plants have been complaining of injury to livestock and vegetation as well as to their own health from the gases discharged into the air during operation of the plants, hydrofluoric acid gas apparently being the offender. The comparatively recent utilization of hydrofluoric acid in the alkylation process for the production of high-octane gasoline has raised the question of the hazard of poisoning in the petroleum Industry. In addition, the use of fluorine-containing refrigerants has extended the potential al exposure outside of industry (2).

Jan 1, 1945

By H. E. Pawson

Giant Yellowknife is located 600 air miles north of Edmonton on the north shore of Great Slave Lake in the Northwest Territories. In its 24 years of operation some 7,730,000 tons of ore have been treated to yield $175,000,000 worth of gold.The gold ore occurs at irregular intervals throughout a fold-like sericite schist zone cutting Precambrian rocks. The ore is characterized by 40 to 80% quartz - carbonate and about 10% pyrite and arsenopyrite. Considerable amounts of stibnite and antimony sulpho-salts are also present. Gold is finely divided in the native state existing in complex association with the sulphides. In most instances stibnite is barren but minor values are evident on occasion. Visible native Fold, quite prevalent in the early operating years, is, practically non-existent today. It was readily apparent from mineral dressing investigations conducted in .1944 that Giant ore would be difficult to treat. By 1948 a flow sheet had been established and operations began. In the ensuing years, changing ore characteristics necessitated modifications to some process steps and complete abandonment of others. By 1962 the major metallurgical problems were solved and all that remained was the refining of operating performance to its highest level.With one or two exceptions today's operation follows the practice established by 1962 (Fig. 1 - Flowsheet).

Jan 1, 1973

By H. W. Kilau

The U.S. Bureau of Mines is evaluating water spray additives for the purpose of improving respirable dust control during coal mining operations, with particular emphasis on the longwall shearer. Recent field tests of surfactant-polymer reagents at two production longwall operations have shown favorable respirable dust reductions compared with water sprays containing no additive. Gravimetric dust samples obtained by a technician downwind of the shearer while following or preceding the machine showed dust reductions in the range of about 40% to 60% for some of the reagent formulations compared with using water alone. Three polymers were tested: two polyethylene oxide compounds of different molecular weight and hydroxypropyl methylcellulose (HPMC). All were effective for dust reduction, and two were cost effective when used in combination with sodium di(2-ethylhexyl) sulfosuccinate surfactant. How-ever, the use of these reagents requires the longwall operator to be more aware of headgate dust control. Experimental evidence indicates that dust captured by reagent-treated sprays at the shearer can be reemitted in the headgate area if stagcloader-crusher sprays and other dust controls are inadequate.

Jan 1, 2010

By H. C. Miller

Several agencies of the Federal Government are engaged in research and fact finding relative to petroleum and natural gas, and others are concerned with carrying out the provisions of specific laws that affect these natural resources in their broad aspects. The Bureau of Mines, however, is the only Federal agency designated by law to engage in research in oil and natures gas production, chemistry, refining, and

Jan 1, 1941

By T. H. Chuang, Y. Y. Shiue

"Rapid whisker growth was significantly alleviated in a Sn-58Bi alloy doped with 0.5 wt.% La. Experimental results showed that many thin, plate-form intermetallic phases appeared in the solder matrix. The absence of tin whiskers was correlated to the shape effect of RE-containing intermetallic plates. After reflowing, Cu6Sn5 intermetallic compounds appeared at the solder/pad interfaces of Sn-58Bi and Sn-58Bi- 0.5La packages with OSP pads, which grow linearly during the aging at 75 and 100? for various times ranging from 100 to 1000 h. In addition, the interfacial intermetallics layers in Sn-58Bi-0.5La solder joints were also observed thinner than those in undoped Sn-58Bi joints. However, RE-containing interfacial intermetallic compounds in Sn-58Bi-0.5La solder joints led to lower bonding strengths in both ball shear tests (0.4 mm/s) and high speed ball shear tests (2000 mm/s). All the reflowed and aged solder joints of both packages were ruptured through the solder balls indicating brittle characteristic INTRODUCTIONIt has been widely reported that solder alloys doped with rare earth (RE) elements reveal many beneficial effects, such as higher strength, lower melting point, improved wettability, and longer creep life (Wu et al., 2004; Ma et al., 2002; Chen et al., 2002). In addition, Dudek et al. reported that the alloying with 0.5 wt.% La in Sn-3.8Ag-0.7Cu solders resulted in an increase of rupture strain, up to 150% over undoped solders (Dudek et al., 2006). However, Chuang and Yen observed that a large amount of long, fiber-shaped tin whiskers were extruded out of the oxidized CeSn3 intermetallic clusters in the matrix of a Sn-3Ag-0.5Cu-0.5Ce solder air-stored at room temperature for several days (Chuang & Yen, 2006). Furthermore, many coarse hillocks appeared around the CeSn3 clusters in the RE-doped alloy after storage in an air furnace at 150? for several minutes. Chuang proposed a mechanism for the phenomenon of rapid whisker growth, which the predominate oxidation of CeSn3 intermetallics in Sn-3Ag-0.5Cu-0.5Ce solders induced compressive stress and extruded the tin atoms out of the specimen in the form of tin whiskers (Chuang, 2007). However, further investigation showed that Sn-9Zn-0.5Ce solders, after long term exposure at room temperature and 150?, were immune to the whisker growth; the immunity was attributed to the refining of the CeSn3 intermetallic phase in the alloy (Chuang & Lin, 2008). The inhibition of tin whiskers through the refining of rare earth containing intermetallics was further observed in Sn-3Ag- 0.5Cu-0.5Ce solders doped with 0.5 wt. Zn (Chuang & Lin, 2009). In addition to the size effect, the thin plate shape of intermetallic compounds was also shown in this study to inhibit the whisker growth on the surface of Sn-58Bi-0.5La solders."

Jan 1, 2012

By M. C. Malamphy

The report of work accomplished on the United States Bureau of Mines' bauxite project in Pulaski and Saline Counties, Ark., is presented in this volume and in a series of Reports of Investigations immediately following this volume. This first volume covers the project as a whole, whereas the subsequent volumes contain maps of local areas and deposits developed, together with logs of the drill holes and descriptions of the separate deposits. The Arkansas bauxite project was initiated in December 1941 and continued for 4 years. The first 5 months were spent in studying the problems presented and in geophysical exploration, Core drilling began in May 1942 and ended in May 1945. The project was one of the larger and more important of those undertaken by the Bureau of Mines for the purpose of developing domestic sources of supply of critical and strategic minerals necessary for National defense and for the successful waging of modern mechanized warfare. Some of the results of the Bureau's bauxite exploratory work have been made available to the public through the medium of press releases, transactions of technical societies, and government publications. More information has been supplied to government agencies upon request and to land owners and mine operators of the deposits concerned in the form of maps showing locations of all holes drilled on the property and logs with chemical analyses of' all cores recovered. In October 1946, the factual data were made avail-able to .the public in manuscript form in an-"open file" at the office of the State geologist, R. B. Foxhall, Little Rock, Ark., and at the office of the. Bureau of Mines in Washington. For the purpose of providing a background for the presentation of the factual data obtained, the history of bauxite is reviewed briefly. Information relative to past production and reserves of bauxite in Arkansas also is given. A resume of the development of the industry in Arkansas, the exploration and mining methods employed, the various uses to which the bauxite is put, and a brief outline of the geology of bauxite in Arkansas complete the -background.

Jan 1, 1948

By V. Gregoire

THE DEVELOPMENT by the Iron Ore Company of Canada of the Quebec-Labrador mining project, which eventually led to 'Iron Ore in 1954', involved, from the start, several distinct undertakings. Among them, the most important were: The construction of a 360-mile railway, linking Knob Lake with Seven Islands. The erection of a railway terminal, and harbour facilities, at Seven Islands itself. The building of an entire townsite at Schefferville (formerly Knob Lake) The construction of two hydroelectric plants; and, finally, The development of a sufficient number of orebodies to enable a production of 10 to 15 million tons of ore a year. Since these phases of the project have already been the subject of previous discussions, this paper will not elaborate further on them but will rather concern itself with a brief outline of the Company's current mining practices.

Jan 1, 1958

By H. L. Willett

Wrapping up the symposium, covers incidence of spontaneous combustion in British mines, assessment of liability to spontaneous combustion, precautions, rate of advance, starting a line of a coalface, local heatings at roadsides, burying packs, coal headings, retreating longwall, detection and sealant coatings.

May 23, 1905

By R Price, B H. Miller

"The rise of autonomous haul truck fleets may have been initially driven by the rapid escalation of the cost of equipment operators, but the actual improvements reported by the major iron ore miners far exceeds the simple reduction in workforce. Utilising cost models developed for feasibility studies and mining contract modelling, the limits of cost improvements due to simple labour reductions are compared to those achieved by the early autonomous fleet adopters and through traditional process improvement techniques such as fleet class upgrades or hot-seating of equipment. As autonomous fleet implementation matures, it is likely that the gains seen by current adopters will seem minor compared to the limits generally governed by the limit of equipment utilisation. This ultimate limit is explored through time utilisation models, which were also developed for use in feasibility studies and mining contract modelling.Citation:Miller, B H and Price, R, 2016. Autonomous Haul System Savings - It's Not about Less Truckies but Better Truckies!, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 2–10 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

By M. Brochu

In this paper, we present a computer-vision approach developed for wall-thickness measurements of corroded pipes inspected by double-wall radiography. The main objective of the work is to optimize data collection and film interpretation using computerized image analysis. To date, the system is able to identify the inner and outer contours of a pipe and perform wall thickness measurements at each pixel of a radiograph. This will be presented by analysing pipes having different dimensions. Another important feature of the system concerns the algorithms' adaptability to pipe wall texture. In other words, image analysis is automatically refined around rough or corroded areas. This allows more precise thickness measurements and shape identification in critical sections as will be demonstrated with examples. Finally a brief overview of results exploitation will be given and compared with human interpretation. It will show the reliability of automated image analysis and the many possibilities offered by complete output analysis.

Jan 1, 2005

By Wolfgang Oberaigner

Primetals Technologies has always been a driver of innovation in steelmaking, especially by providing sophisticated process expert models for continuous casting machines. This capability is demonstrated by recent advancements in automation solutions that include: DynaPhase, Dynacs 3D, and DynaGap. This state-of-the-art suite of dynamic secondary cooling and soft-reduction packages take into account thermodynamic effects such as shrinkage and phase transitions, and thereby significantly contribute to direct quality improvements during the solidification phase in the continuous casting process. Speed Expert calculates an optimum casting speed for every casting situation, and additionally recommends a strand speed so that the point of final solidification is positioned at the end of a segment for optimum soft reduction. In the case of steel grade changes, the Intermix Expert precisely calculates the chemical properties of the mixed steel, thereby minimizing losses due to deviations from required specifications. The Nozzle Expert is a new model that detects clogged nozzles and broken hoses in secondary cooling systems. The first installations were highly successful and customers are pleased with impressive reductions in maintenance costs and improved steel quality. This paper describes these innovative process automation solutions and gives an overview about the successful results achieved within the first installations.

Aug 16, 2017

By Gerson León Cervantes

El presente texto evalúa la mejor opción técnico-económico para el transporte de concreto lanzado (shotcrete) a interior mina. Para ello, se evalúan tres alternativas logísticas excluyentes: el primero, consiste en instalar una planta de concreto en superficie y realizar el traslado a interior mina mediante mixers. El segundo, consiste en establecer una planta de concreto en interior mina del centro de gravedad de las operaciones, y el tercero instala una planta en superficie y se envía el concreto a la mina por medio de tuberías. En la evaluación de las dos primeras alternativas, se tiene los resultados de la mina San Cristóbal y Cerro de Pasco, pertenecientes a la empresa Volcán, mientras que para la tercera alternativa, se tiene la data de la mina Diamond Cullinam en Sudáfrica.

Feb 1, 2013

By Lake H. E.

The request to participate on your theme panel was accepted with some reluctance but indeed as an honor. My subject was outlined to cover 'Energy Resources - both nuclear and conventional' as related to your theme 'Minerals - Treasure Trove of the West'. This is indeed quite an order and I hope you will forgive me for concentrating mainly on the nuclear-uranium portion with brief references only to conventional fuels some of which will be covered in detail later in your conference. In regard to Uranium, I am speaking on the fringe of the area containing half the uranium reserves in your country and no doubt to many who are very conversant with knowledge of these resources. Nevertheless since our two countries have been very closely allied in both nuclear developments and uranium supplies I hope an exchange of information may be mutually beneficial. Concentration on the nuclear fuel resources is I hope understandable as nuclear energy is the coming source of power which will augment the rapid demand in the industrialized countries and provides hope for economic power in many of the more underdeveloped countries. The situation regarding conventional fuel resources is more widely known and their expanding future revolves around production cost reductions, research into diversified uses, plus more assurance of imports from countries less effected by international controversies determining export policies.

Jan 1, 1967

By W. R. Huff

This report describes the development and operation by the Bureau of Mines of a pilot plant designed for using high-volatile A bituminous coal-in-water suspensions as a source of preheated coal and superheated steam in the pressure gasification of coal with oxygen. Figure 1 on page 2 is a block diagram of the integrated gasification process, in which a total of 70 tons of coal was fed from slurry and gasified. The present work included (1) development of equipment and methods both for mixing pulverized coal and water to produce slurry and for pumping and metering the slurry at gasification pressure; (2) development of equipment for heating the flowing slurry and, because slurry that can be pumped produces more steam than is necessary as a gasification reactant, developing equipment for removing and metering the excess steam; and (3) demonstration of the process under actual gasifier operating conditions, at a coal rate of about 800 pounds per hour and gasification pressures in the range 100 to 300 pounds per square inch gage. By using the forced-convection principle, a flow of slurry made from a caking, high-volatile A bituminous coal can be continuously heated to 600° F. in a coil-type heater. The flow rate and concentration of the slurry and the temperature gradient along the length of the heating coil must be closely controlled. In a radiant-type heater, involuntary reductions in flow rate, even momentary, can lead to coking and plugging of the heater coil.

Jan 1, 1961

By M. H. Salsbury

This report describes the tunneling at the Leadville drainage tunnel, which was resumed in September 1950 with funds made available in the 1950 appropriation of the Department of the Interior. It brings up to date the account of the first project, carried on from December 1943 to August 1945, published by the Bureau of Mines which supervised both the first and second projects. In this report Leadville mining history, particularly related to drainage efforts, and the possibilities for future mine drainage are discussed briefly. An account of the second project, including a description of the operating cycle, exploratory drilling done as a safety measure, surveying procedures, geology, cost data, and other pertinent information, completes the report.

Jan 1, 1956

By Nicole Peter

When introducing digital training technology a practical approach helps address cultural concerns.  Solutions to help create acceptance are discussed.  Resistance to change may be deeply rooted in traditional mine training personnel.  Traditional training staff members may consider themselves less digitally-savvy and resist technological methods available to them. A transitional approach intended to help mitigate or resolve resistance is presented as a continuous improvement pathway toward full adoption.  This presentation contends every mine should welcome the benefit of a digitally connected critical enabler.  The adoption of a digitally savvy learning centre is often viewed a disrupter to existing practice.  Given a commitment-driven learning centre model, technology offers the opportunity to transition from a compliance-based training model to one of competence.  Learning and Development practitioners should welcome the latest advances in neuroscience, Bloom’s taxonomy of learning model, and principles which guide mine safety training as outlined by the Lowell Institute for Mineral Resources at the University of Arizona. By employing digital applications to include animation, game-based simulations and immersive Virtual Reality (VR) these technologies create a viable digitally-savvy learning centre. We will outline the ingredients of a digitally enabled, or VR, Learning Centre to offer some observed benefits, successes, and potential short-comings. Much excitement in the industry surrounds implementation of simulation and/or VR headset training.  Given fair consideration of these as a ‘fit-for-purpose’ solution we examine the paradigm shift required to create real results for on-the-job learning.  Interim steps may be needed to meet the cultural transformation.   Simpler forms of VR, in the form of 3D models and VR environments as displayed on a large interactive touch screen, can serve to bridge this challenge and address a group learning environment. Features of the interactive 3D technology and ease of adoption are presented.  Usage of the touch screen is similar to that of a smart phone. It may be implemented as an obvious transitional tool.  To help describe merits of the interactive touch screen the presentation points out these sample underground and surface mine training applications. There are 3-D simulations such as ventilation, emergency response, support installation, and mine cycle and activity scheduling programs. These applications offer the ability to conduct entry examinations, complete digital pre-use checklists, and perform planned task observations in the virtual world of work. The tool may be used to teach the flow of hydraulics and do fault-finding on machinery such as loaders and dump trucks. Learners may navigate in a virtual mining environment to identify hazards, detect and assess abnormal ground conditions, address poor design features, and alleviate traffic constraints. It is possible to use connected physical controls to navigate machinery in the virtual environment. We conclude the presentation with a “compare and contrast” approach to cite potential cultural benefits by adopting a transitional method. 

May 4, 2025

By L. A. Panek

A new pillar strength formula is presented, incorporating a function P of size and shape, which takes into account the size-shape interaction effect as well as the enhanced strength exhibited by wide pillars. Existing pillar formulas, lacking these capabilities, are not suitable for extrapolating small-specimen test results to mine-pillar sizes and shapes. Interpreting compressive-strength test results as function of P clearly reveals wide-pillar behavior in much old test data. Model relationships are discussed, along with their scaling implications.

Jan 1, 1994

By Paul M. Tyler, R. M. Santmyers

Platinum and its allied metals osmium, iridium, rhodium , palladium, and ruthenium are the most costly of the better-known metals and combine properties that make them unique among the elements . For a number of isolated uses substitutes have been found which are cheaper and quite as satisfactory ; but none will replace platinum in many of its varied uses , and there is a large and growing demand for purposes for which no economical substitutes are known . As this paper is being written the supply of platinum tends further to increase as a result of the exploitation of newly developed resources and the expansion of production from older sources . In obedience to economic law prices have declined steadily . Buyers , always reluctant to commit themselves on a falling market , have maintained a waiting attitude , and consumption trends are not clearly indicated . Should platinum again approach the price of gold , the natural tendency would be to use more of the metal . In recent years , however , the industrial and scientific uses of platinum have become subordinate to its consumption in jewelry . In matters of personal adornment the popular whim and not practical utility is the dominant factor in demand , and it does not follow that lowered prices will stimulate demand . The substitution of white gold and certain plated goods for platinum may be checked by cheaper platinum , but a fickle public that turned from gold to platinum when platinum became the more costly metal can not with certainty be expected to buy more platinum jewelry because more of the metal than formerly may now be had for the same price . The dearth of platinum during and for some years after the World War had a profound effect upon prices , and this in turn wrought important changes in the field of consumption . When prices advanced the chemical industry, formerly the leading consumer of platinum, was forced to economize in its consumption of the metal and to substitute other metals whenever it could . Somewhat similar conditions resulted in the electrical industry and in the use of platinum in dentistry . Some of these former outlets are permanently closed , and others may be reopened now that platinum prices have receded to pre-war levels , but despite the general expansion of industrial and scientific activity since 1913 the demand for platinum outside the jewelry trade has suffered a net decline . Since the metallurgy of platinum is relatively simple the reason for its high price is its relative scarcity in the earth's crust . An interesting speculation set forth by certain geologists attributes the extraordinarily high density of the interior of the earth in part to the presence of iron alloyed with substantial amounts of platinum and other related metals . In support of this hypothesis it may be said that platinum is often found in meteorites , and known deposits in the earth's crust are all of deep - seated origin . However , even if there were a high concentration of platinum in the interior of the earth it would be next to impossible at the present state of our knowledge to make it available , and the world would continue to depend for its supply on deposits found within minable depths below the surface . For many years before 1914 the world obtained its supply of platinum metals primarily from Russia , which before the war produced as much as 300,000 troy ounces in a year , or approximately 95 per cent of the world output . Despite fluctuations due to internal political disturbances Colombia managed to account for 3 to 4 per cent , leaving the rest of the world to furnish the remaining 1 to 2 per cent .

Feb 1, 1931

By John W. Antalovich

Normally I would like to begin a talk on photogrammetry by defining the word. However modern technology has changed the science so radically that it bears little resemblance to its original definition. Photogrammetry as defined is a science of taking accurate measurements from photography. Today's photogrammetrist, in addition to working with photography, finds himself working with magnetometers, infrared scanners, radiometers, holo¬graphy, lasers, side-looking radar, digital interfaces, computers and countless other modern space age concepts. The modern photogrammetrist is a pilot, photographer, lab technician, mathematician, geologist, programmer, engineer, physicist, and cartographer. His modern instrumentation and many spheres of activity all have a role in the environmental sciences. For example, the magne¬tometer which measures the earth's magnetic fields is used to locate the earth's ore deposits. The infrared scanner captures the heat emitted from the earth to detect ground waters and thermal pollutions. To elaborate on each of his many endeavors would take volumes rather than this short paper. I have elected therefore to discuss what I feel is his most important role in the environmental sciences - that of cartographer.

Jan 1, 1970

By B. H. Clemmons, C. H. Schack

Extractive metallurgy techniques currently employed to recover silver from primary ores and secondary scrap were reviewed and evaluated to identify and delineate metallurgical problems whose resolution would increase the supply of silver from domestic materials. The survey revealed that practically all primary silver is recovered by froth flotation concentration of various types of ores, followed by smelting and refining of the separate lead, copper, and zinc concentrates. Silver losses during the complex processing are, with rare exception, inconsequential. Furthermore, any silver production gain from base metal ores, which contribute about two-thirds of the total primary silver, is directly dependent on improvement in the market for the base metals. Statistical data on new and old silver scrap are wholly inadequate to make reliable conclusions about scrap processing problems and the possibility of increasing the recovery of silver from the many forms of secondary silverbearing materials. The available information indicates (1) that efficient silver reclamation practices are employed by the larger users of silver, and (2) that recovery of additional secondary silver involves solution of problems of collection rather than of processing. Several possibilities exist for limited increases in silver production from primary ores by improvement in metallurgical practices. Specifically, research is needed to (1) solve the problem of recovering silver from the copper ores of the Copper Range district, Michigan; and (2) devise economically feasible methods for recovery of silver from presently marginal or submarginal ores that because of grade, location, and frequently complex nature cannot presently be exploited by conventional techniques.

Mar 1, 1965