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By R. S. Handy

This paper describing the milling practices at tae concentrators of the Bunker Hill and Sullivan Mining and Concentrating Co. is one of a series being prepared by the United States Bureau of Mines on milling methods and costs in the United States. The possibility of useful comparisons has prompted the description of all five of the mills operated by the Bunker Hill and Sullivan Company in northern Idaho. The general features of these mills are tabulated below: [ ]

Jan 1, 1930

By L. A. Neumeier

The Bureau of Mines investigated hot-rolling and forging characteristics of experimental ductile iron castings, both sand and permanent-mold, made with charges containing up to 70 pct foundry pig iron and 95 pct steelmaking pig iron. Between 1,550° and 1,950° F, most castings could be rolled to 90-pct reduction or forged to 70-pct reduction without serious cracking. Charge and composition have less bearing on workability than on subsequent properties. Permanent mold castings could be worked as readily as sand castings at 1,750° and 1,950° F. Plasticity improved with temperature. Small billets were also forged cold to 50-pct reduction without cracking. With equivalent nodularity, composition affects properties of wrought materials by altering matrix structure and strength. Properties vary with reduction and improve with increasing working temperature. Rolled material has high strength and anisotropy, and low ductility, particularly in the trans-verse direction. Annealing reduces strength and improves ductility, but anisotropy persists. At 70-pct reduction, impact resistance in the longitudinal direction is about twice that in the transverse. Annealing roughly doubles impact resistance. Deformation enhances damping capacity. The feasibility of die-forging and bar-rolling of ductile iron was evaluated in trial tests conducted under a Bureau contract. Although workability and ductility of ductile iron are inferior to those of steel, more advantage could be taken of ductile iron's plasticity to work rough shapes to final dimensions.

Jan 1, 1980

By G. W. Josephson

JUDGING by the progressive atmosphere prevailing in the nonmetallic mineral industries during the past year, postwar conditions were healthful though inflationary. Demand for most industrial mineral products has been exceptionally high and many new production records were attained. Severe shortages of some commodities existed, especially building materials and fertilizers. Production costs and prices increased and profitable operation was general. Under these conditions expansion programs were the order of the day. Ample funds were available to finance the purchase of good equipment; and, as wages and other operating costs were increasing, primary emphasis was placed on attaining maximum efficiency in new installations. These efforts were hampered by shortages and slow delivery of desirable equipment, so compromises in design were often necessary. However, on the whole, production practice improved.

Jan 1, 1948

When I was first asked to give a paper on work-life balance in the mining industry I was both excited and aware of the incongruity of my position. I have never worked in mining operations nor have I had any experience that approximates the on-site lifestyle. IÆm not really an adventurer or a traveller, I prefer writing and research to hands-on activities and IÆve never worked further than twenty minutes away from home. The perspective I offer is thus largely an objective one. I say largely since I grew up in a family where my parents work arrangements involved long-distance commuting; my dad continues to work FIFO at a coalmine in Blackwater until this day. Perhaps my tortoise-like existence is a rebellion against his flighty movements. The analysis I will be presenting today draws together a variety of sources, from member anecdotes and research on FIFO and work-life balance to the popular philosophy writings of a bald Englishman with a French name. I am speaking of the famous writer, Alain de Botton, whose television show æThe Consolations of PhilosophyÆ you may have seen on the ABC. Work-life balance is a term that gets a lot of mileage in corporate brochures and at breakfast seminars. But like many terms that get bandied around in the human resources circuit, from æteam synergyÆ to æperformance optimisationÆ, I am frequently perplexed as to what it actually means. Corporate websites are at pains to emphasise the high priority that they place on the needs of the whole person. Yet in terms of substantive content, a commitment to work-life balance often seems to translate into little more than the option to take a few morning yoga classes in exchange for working a seventy-hour week. As extended work hours have taken their toll, leading to high attrition of professionals across all industries, employers are increasingly expending resources to discover just what lies behind this buzz word. The challenge for companies is to find meaningful strategies to help employees better integrate different aspects of their lives in a new era of work, as employees are sending the message that they are not willing to play work, social life and leisure off against each other in a zero sum game.

Jan 1, 2005

By A. Halim, J. Gustafsson, A. van Wageningen, J. Johansson, · J. Lööw, K. Kocsis

A major part of the European Union’s (EU) project Sustainable Intelligent Mining System (SIMS) is investigating the development of diesel-free/carbon–neutral underground mines in order to ensure sustainable underground mining in the future. Replacing diesel machines with electric vehicles in underground hard rock mines has been widely acknowledged by the mining industry worldwide as a critical step to improve working conditions by reducing diesel exhaust–related contaminants, to reduce mine ventilation electrical power cost by reducing mine airflow quantity, and to reduce mine greenhouse gas emissions. All of these are major requirements to achieve sustainable future underground mining practices. A field trial of Epiroc’s 2nd generation of Battery Electric Vehicles (BEVs) at Agnico Eagle Finland’s Kittilä mine was conducted during 2019–2020. Vehicles tested were MT42 mine truck, ST14 Load-Haul-Dump (LHD), and Boomer E2 jumbo drill rig. This paper outlines the improvement of the working conditions observed in the field trial, and the opinions of the mine personnel at Kittilä mine on using BEVs instead of diesel machines. Measurements of atmospheric contaminants and air temperatures taken during the field trial clearly demonstrated a significant improvement of working conditions when BEVs were operating as opposed to diesel machines. This field observation was supported by the opinion of the majority of the Kittilä mine workers. However, some remaining concerns must be addressed before BEVs can replace diesel machines.

Oct 25, 2021

By David A. Monaghan

This report describes the results of a 2-year investigation of extensible face ventilation techniques and systems for use at the working face in underground coal mines. The goal was to provide a safe and convenient method of maintaining the extensible system within 10 feet of the face, thereby ensuring good ventilation. A summary of approximately 20 extensible ventilation systems proposed or tried in the past is included for reference, together with a detailed description of the design, construction, and underground testing of a new extensible brattice panel and a new fiberglass duct system. The extensible brattice system utilized a special panel which could be pushed forward as the miner advanced. Brief testing in three mines revealed some conflict with the mining cycle and led to recommendations for two improved designs. The extensible duct system was designed for a Goodman borer and utilized a telescoping tube on the left side of the roof, so that it could be extended without interfering with the miner operator. For mine sections with right-hand return ventilation, a special flat tube section is used to cross over the entry. Underground testing showed substantial improvement in face ventilation without interfering with production.

Jan 1, 1976

By P. Sarnoff

Gold has always been a crisis investment. For centuries gold has been considered globally the money of last resort. In time of war, inflation, financial uncertainty, political upheaval there has with few exceptions always been a flight to gold. The gold paradox simply is that even though we have gone through for the past handful of years all the kinds of. anxieties that would cause the gold price to rise, it has instead dropped drastically. Figure 1. illustrates the important factors that influenced the gold price significantly up or down before 1987. Obviously, since then, even though we have had wars, inflation, financial problems involving breaking banks and thrifts let alone collapsing financial institutions, the gold price has both in the long-term and the short-term trended downwards. Figure 2. depicts the gold price path since 1987. If the presence of time-honored and time-tested factors that should have driven the gold price up didn't do the job, then logic dictates that new factors to drive the gold price down and keep it depressed arose. And they did. But before addressing these depressants permit me to turn to the arcane art of gold price prediction and fore-casting.

Jan 1, 1992

By Forrest T. Moyer

The safety record of the coal-mining industry, both anthracite and bituminous, in 1966 was improved over that of 1965 in all general measures of injury experience. The improvement was more pronounced in the anthracite industry. The total of 10,679 disabling work injuries comprised 233 fatal and 10,466 nonfatal injuries, 26 and 692 fewer, respectively, than in 1965. The number of fatalities in 1966 was the lowest annual total since complete records were started in 1910. Similarly, the number of nonfatal injuries in 1966 was lower than in any year since 1930 when such data were first collected.

Jan 1, 1969

By J. R. Thoenen

Up to 1914 almost all of the world's supply of potash came from Germany and Alsace. With the cessation of shipments from Germany during the World War the importance of a domestic suppler was evident. During the past 15 years the United States has been working toward the establishment of a domestic potash industry which would end foreign dominance in this commodity. The Federal government has taken an active part in this program. As its share in the work, the Bureau of Lines has ascertained the potash resources in certain district's through core drilling and has engaged in a comprehensive program of research on the extraction of potash from its various minerals. Until the passage of the Winter bill (H. R. 496) by Congress in 1928 the Bureau of Mines had not been able to give any consideration to the western ores, wyomingite (leucite) and alunite. With the massage of this bill, however, the ray was opened for the extension of the potash studies to cover these materials.

Jan 1, 1932

By Payman Roonasi

Having knowledge of mechanism of magnetite formation is essential in a number of industrial processes including magnetite synthesis and corrosion of iron. In this study, magnetite nanoparticle was synthesized via two different ways; coprecipitation of iron (II) and (III) and oxidation of ferrous hydroxide. The samples were characterized using X-ray diffraction (XRD), Mid-Far IR spectroscopy, scanning electron microscopy (SEM), chemical analysis for determination of Fe II/Fe III ratio and ICP-MS for iron isotopic ratio (56Fe/54Fe) measurement. Since fractionation of iron isotopes depends on reaction rate and bonding strength, interpretation of the isotopic data with respect to the possible mechanisms is discussed. No fractionation of iron isotopes was observed for the magnetite synthesized by coprecipitation, whilst magnetite formed from ferrous hydroxide showed higher abundance of 54Fe compared to 56Fe in the beginning of reaction, implying the significance of the following reaction:

Jan 1, 2009

By GRANT COLLIGAN, BROCK O’KELLEY, Corby Anderson

With the world’s ever-growing push to expand technological capabilities, the need for specialized materials including rare earth elements has exploded. One source of rare earths found in the United States is bastnaesite, a rare-earth-bearing fluorocarbonate, mined at the Mountain Pass Mine in California. To increase production, it has been essential to optimize existing processes and create new ones to capture current reserves. This paper presents the results of a research program conducted to expand the understanding of the bastnaesite leaching system. With the help of prior knowledge and thermodynamic calculations, a novel single-stage hydrochloric acid leach system was created to optimize the extraction of rare earths from bastnaesite. Historically, this extraction has entailed the use of a two-stage leach system involving a high-temperature hydrochloric acid leach followed by a caustic crack. We ran a series of single-stage leach experiments by reacting locked-cycle flotation concentrate with hydrochloric acid to test common leaching parameters. The results of these single-stage tests showed significantly higher rare-earth recoveries than the reported recoveries of the historic two-stage caustic crack processes, all while decreasing the number and amount of reagents needed.

Feb 1, 2023

By Frederic P. Dewey

The Bureau of the Mint of the United States Treasury maintains 13 ofEces for the purchase of gold-bullion, and this paper describes an investigation to establish the reasonable differences in the assay-results at the various institutions which may be commercially allowable in the settlements between them. Beginning with the comparative assay of proof-gold at the Philadelphia mint and the Utrecht mint, which shows 0.00002 as the closest agreement now possible, nine tables of comparative results, taken from the regular work of the service, are given..These tables begin with very fine gold, produced in an electrolytic refinery, showing close agreement in the assay-results, and follow through decreasing gold fineness and increasing amounts and complexity of base metals to very impure and complex bars produced at cyanide-mills, some of which give widely-varying results. Next is given a series of results on samples, prepared and sent out to various laboratories in the service, to test the influence of different metals and various combinations upon the agreement of the assay-results ; 11 samples were sent out and each one was assayed from 44 to 71 times, making a total of 623 assays. To these ire added 107 assays of identical samples of coin-gold. On a previous occasion,' I have endeavored to show the degree of accuracy that may be expected in the ordinary everyday analysis of various materials, and on another occasion,2

Jan 1, 1910

By Henry P. Cole

A series of studies are described that identify critical health and safety skills needed by underground coal miners for coping with mine emergencies. First aid and self-rescue and escape were selected as two broad performance domains that include many subordinate skills needed for preventing, recognizing, and coping with mine emergencies. The performance domains and their objectives were used to direct the development of simulation exercises that permit miners to experience mine emergencies in the safety of a training room. The exercises are based upon research with similar simulations for the training of flight crews and medical personnel in information gathering, judgment, and decision making skills. Exercise content is drawn from actual mine accident and disaster case studies. The exercises incorporate recent principles of cognitive psychology and instructional design. Initial studies in annual refresher training classes suggest the exercises are stimulating for miners and their instructors, easy to use and read, sufficiently complex and authentic to challenge experienced miners, and useful devices for both teaching and testing critical problem solving skills required for preventing and minimizing emergencies.

Jan 1, 1988

By J Harris, P Kirsch, D Cliff, M Spinks, S Goater, D Sprott

Fires are a common and recurrent unwanted event in the operation of open pit mines. In most cases, the causes of events such as fires are already æknownÆ but are either overlooked or not fully addressed in planning. Ongoing rapid growth of the global mining industry is creating a scarcity of skilled personnel, and high turnover within operations. This contributes to loss of corporate memory in risk management activities. RISKGATE« is an online risk management system designed to support and assist in the analysis of priority unwanted events in Australian coal mining operations. Funded by the Australian Coal Association Research Program (ACARP), RISKGATE« is a knowledge management program that delivers best-practice controls for unwanted events and assists operations in staying abreast of emergent risks and threats. RISKGATE« content has been primarily developed from an association of industry experts, and enriched with input from additional academic and technological resources. In mining operations, RISKGATE« provides a continuum of knowledge and best practice for risk identification, assessment and management. RISKGATE« will assist companies in improving safety performance, operational efficiency, operating practice and training. Here we present the RISKGATE« prototype as developed in 2011 for Fires, with a case study presented for the initiating event Fires on Mobile Plant.CITATION:Harris, J, Sprott, D, Spinks, M, Cliff, D, Goater, S and Kirsch, P, 2012. RISKGATE« - A case study in application to fires on mobile plant, in Proceedings Eighth Open Pit OperatorsÆ Conference , pp 49-54 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 18, 2012

Despite the fact that mined minerals and gemstones have allowed human beings to continuously improve their standard of living throughout the ages, mining has also been implicated in violent conflict for two principle reasons. The first is that mineral resources have been used or traded to conduct or finance violent conflict from small to large scales. The second is the substantial social, economic and environmental changes that occur in a community or a region as a result of mining activity which can either precipitate or re-awaken latent conflict. A modern complication of mining-related violent conflict is the trend for activists, international NGOs and intergovernmental organisations (e.g. the United Nations) to regard any human consequences of resource extraction in terms of Human Rights violations. Acknowledging but not labouring the Human Rights implications of mining-related violent conflict, this paper explores whether or not there is a relationship between the actual or perceived value of mineral resources and the level of violence that occurs in mining-related conflicts. Key to the investigation is a mapping exercise of mining related conflict from 2005 ? 2012: to see where mining related conflict is happening; to identify precipitant causes of mining related conflict; and, to discover what correlation ? if any ? there might be in the degree of violence and the value of the mineral(s) implicated. Findings of the analysis are presented in this conference paper.

Aug 1, 2013

By Mark Lawshe, Shosie Serata

The conventional method of mining underground, using narrow rooms and wide pillars, has proven to be poorly adapted to the powerful earth forces that act on underground openings. The high costs of roof bolting, timbering, steel arching, and other means of artificial roof support for both room-and--pillar operations and longwall gate roadways attest to the limitations of traditional mine design. Too often, productivity halts when corners buckle under "cutter roof' stresses, floors heave, and roof strata fall. In the 1960s, an entirely different approach to strata control was developed. The Stress Control Method (SCM) stabilizes failing roofs and heaving floors by removing the cause of failure - highly concentrated stresses around the openings. This is achieved by regrouping three to 10 rooms into a single entry where the rooms are separated by very narrow yielding but stable pillars. SCM employs a specified excavation sequence to redirect earth pressures away from the mine openings. The yield pillars act as scaffolding until a permanently protective secondary stress envelope forms around the entry (lower part of Fig. 1). The result is a dramatic improvement in roof stability and a significant reduction in artificial support costs. Some roof bolting must still be done, mainly to meet Mine Safety and Health Administration (MSHA) requirements. Potash, salt, coal mining The stress control method was first applied to the deep potash mines of Saskatchewan. The new SCM design actually increased room widths to enlarge the stress envelope, redistributing the stress concentration away from the entries (Serata and Schultz, 1972). This resulted in a turnaround from pervasive roof fall/floor heave conditions that threatened operations in the eight new mines opened in the Saskatchewan potash field during the 1960s. In addition to eliminating all roof bolting, SCM successfully stabilized ground conditions and substantially increased productivity over the original design (Serata, 1976, 1982). Similarly, the deep Boulby potash mine of Yorkshire, England, was about to close after various conventional means of combating roof failure had failed. An SCM test area was excavated that resulted in the ground quickly stabilizing without need o artificial support (Serata, 1982; Chilton and Laird, 1982). Another example is the Diamond Crystal salt mine in Louisiana. Here, multiple level mining was being extended from the third to the fourth level downward in the Jefferson Island salt dome. Extensive roof failure was occurring at 396 m (1300 ft) ii the third level. SCM design principles in creased the room size from 24 to 49 m (80 t( 160 ft) on the fourth level at a depth of 457 m (1500 ft). This unprecedented expansion of room width was first questioned and later ap¬proved by MS HA, which expressed satisfaction in seeing the improvement documented by field validation data in 1973. The most recent SUM application to salt mining has been in the Michigan Basin a: Goderich, Ontario. The anticipated abandonment of Domtar Chemicals Group/Sifto Salt Division's deep operation in bedded sale was prevented by a multi-year SCM implementation. The success of SCM in dry mining[lecc] to its application to solution mining of salt This adaptation of the method is now being implemented in bedded salt at Fort Saskatchewan, Alberta by Dow Chemical Co., and in St. Clair, MI by International Salt Co. Application of SCM to solution mining in a salt dome is proceeding at Napoleonville. LA by Dow Chemical. The same technology has also been applied to cavern design for the Louisiana Offshore Oil Port (LOOP), and the compressed air energy storage (CAES)

Jan 1, 1989

By C. A. Heiland

THIS year's review of geophysical activities has a somewhat different complexion than usual. With the ending of the war, the time seems opportune to supplement the customary report on operations and discoveries in oil and mine exploration by a review out-lining the contributions of geophysicists to the. war effort. To give as much space as possible to the latter, presented as Part 2, some of the usual review features have been omitted from the statistical section, given as Part 1 immediately following.

Jan 1, 1946

By Nathan W. Iverson, David S. Graham, Paul J. Axtell

"The Highway 53 relocation project in Virginia, Minnesota, involves construction of a very tall bridge across a currently inactive iron ore mine pit. The inactive pit is partially flooded and serves as the community’s drinking water source. The 1,132-ft long new bridge is a three-span, plate girder structure. Two intermediate, approximately 200-ft tall piers are located within the pit.The foundations for the two piers consist of groups of 30-in diameter piles which, despite the contradiction in terms, are essentially very large micropiles. Extremely challenging and highly variable subsurface conditions exist at the site, ranging from uncontrolled iron ore mine waste fill to some of the hardest rock on earth that can also be highly fractured and abrasive. Despite the conditions, large diameter (30-in) micropile foundations up to 175 ft deep were successfully installed using down-the-hole hammer methods and full-length permanent casing under an extremely aggressive construction schedule.Full-scale foundation load testing using the Statnamic rapid loading method was also conducted in support of the design and construction but under a separate pre-design phase contract. This paper describes the unique aspects of this foundation project, including design, construction, and load testing of the large micropiles.INTRODUCTION AND BACKGROUNDIn 1960, a segment of Trunk Highway 53 (TH-53) in Virginia, Minnesota, was built on land owned by iron ore mining interests. As part of the roadway easement agreement, Minnesota Department of Transportation (MnDOT) was to be given notice three years prior to termination of the easement. In 2010, MnDOT received notice that the mining interests wished to access the ore. Through negotiations in 2010, MnDOT and the mining interests agreed to a 2017 date for abandoning the existing section of roadway. During this period, MnDOT needed to procure project funding, satisfy environmental permitting requirements, and acquire new right-of-way to permanently reroute TH-53 and keep it open to traffic. This was no easy task due to the existing mine pits surrounding the area.The E-2 alignment option shown in Fig. 1 was ultimately selected for the rerouted highway in 2014. The new highway segment includes a three-span bridge across the currently inactive Rouchleau Mine Pit. The inactive pit is partially flooded and serves as Virginia’s drinking water source. The 1,132- ft long new bridge is a three-span, plate girder bridge. Two intermediate approximately 200-ft tall piers are located within the pit. Fig. 2 is a conceptual rendering of the bridge."

Jan 1, 2017

By R. S. Dean

The original flotation reagents were certain oils selected for a combination of properties that occurred fortuitously. It was recognized quite early in the study of flotation mechanism that, in order to function, an oil must have an active group-one that differs from the remainder of the molecule in its affinity for water or the mineral particle. Wark4 gives credit for recognition of this elementary chemical principle to the senior author of this report.5 However, it was soon found that simple hydrocarbons could not be used as flotation reagents and that two of the functions, which were combined in the early flotation oils such as pine and eucalyptus, could be obtained in separate compounds and their relative intensity controlled to advantage. These two functions were called collecting and frothing.

Jan 1, 1944

By M. W. Buche, E. Tarshizi, R. Chappidi, B. Inti

"Coal mining is an age-old method of power production in the world. It is also widely known for the associated risks during mining. Although the number of mishaps has dropped dramatically over the years, the number of fatal accidents is still a concern, and any aid in reducing these figures would be important to industry workers. Therefore, data from accident reports during the past seven years were collected and analyzed. Qualitative data from reports and articles provide a deeper understanding of the incidents, thus affording the possibility of identifying patterns and relationships between the accidents. For this study, a total of 119 fatality accidents occurring in U.S. coal mining operations were analyzed using advanced text mining techniques. The fatality data were obtained from U.S. Mine Safety and Health Admininstration fatalgram reports. This analysis is primarily exploratory in nature and uses term frequencyinverse document frequency (TF-IDF) methodologies along with correlation network plots. An interesting word relation pattern was obtained that identified “positioning” as the common cause of 12.6 percent of accidents, and found that 29.4 percent of accidents can be categorized as vehicle-related. IntroductionIn the mining industry, accidents are situations that employees and employers wish to avoid. They are devastating experiences to the victims and their coworkers alike. Even worse, accidents that result in fatalities create trauma and undesirable repercussions. Several measures have been taken throughout the industry to prevent such mishaps, and the U.S. Mine Safety and Health Administration (MSHA) provides continuous monitoring for miners’ safety by guiding organizations through best practices in every job role. As a result, according to MSHA, there has been a steady decline in the average number of deaths due to accidents over time. Nonetheless, any opportunity to avert one more such casualty is of paramount importance, and that is the goal of our analysis. Our objective is to identify opportunities resulting from previously unexplored directions in order to provide additional insights into potential safety recommendations. Until now, most of the studies in this area had been conducted using structured and tabulated data with a constant number of categorical and numerical variables. Unstructured text data mining is an emerging area that is still insufficiently researched and has a feasible scope for important results, as a vast majority of human communication and cognizance is comprised of words. The aim of undertaking this project by capitalizing on unstructured data is to analyze the text reports to discover potential relationships that explain the causes of accidents in new light in order to mitigate the occurrence of fatalities. The analysis in this project is based on textual data obtained from the MSHA website (2017). Individual accident reports are organized according to the date and year of the fatality. Each report includes details with images of the incident. For convenience, a simplified summary of the report is also available. Data collection consisted of gathering formal documentation of fatal accidents in the coal mining industry during the past seven years. These reports were extracted from the website in text format."

Jan 4, 2018