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By Arnold M. Lansche

[Selenium and tellurium are rare elements in the earth's crust. Their scarcity and primary dependence of supply on copper and lead output are in consonance with the relatively small quantities consumed at 1964 level. Production depending on output of copper and lead creates a supply situation- which would appear to militate against development of large-scale usage of these elements. However, supplies have adequately met. demand in the past decade and can be increased substantially if warranted by new uses for either selenium or tellurium Ores of copper and lead re the principal sources of selenium and tellurium. Byproducts from the smelting and refining of copper and lead concentrates are incorporated in refinery anode slimes from which selenium and tellurium metal are recovered.]

Jan 1, 1967

There is a saying, ?If it moves, it vibrates.? This is especially true in our modern industrial environments, where workers use powered tools, machinery, vehicles, and heavy equipment. How workers are affected by these elements of the industrial working environment is a concern of health professionals, govern­ments, and scientists around the world. How to adequately assess the effects of human vibration exposure is an equally important issue. The human body comprises a dynamic structure that is living, intelligent, and complex. Consequently, it is not unreasonable to consider that exposing the body to an array of vibration environments would result in outcomes that are not necessarily simple or easily predictable. Sensations caused by vibration may include nausea, annoyance, discomfort or pain, and exhilaration or pleasure. Many factors contribute to the effects of vibration on humans, including the characteristics of the motion and the exposed indi­vidual, the activities of the exposed individual, and various elements of the environment. There have been attempts to summarize the effects of occupational vibration exposures by simply recommending the avoidance of certain frequencies of vibration or by providing a graphical method, i.e., a single curve displaying all human responses to all frequencies. However, such efforts have not withstood the scrutiny of scientific research and analysis. Thus, attendees and participants at this professional gathering now have the rare opportunity to benefit from the technological advances and new scientific research to enhance their understanding of human responses to vibration that suggest more than a simplistic approach. In the tradition of the First American Conference on Human Vibration (1st ACHV) held in Morgantown, WV, June 2006, the 2nd ACHV provides a forum for scientists, engineers, medical doctors, industrial hygienists, and educators to learn and advance research and education in the specialized area of human body vibration. The conference was organized by the Mechanical and Industrial Engineering Department, University of Illinois at Chicago, with support from the National Institute for Occupational Safety and Health (NIOSH), Pittsburgh Research Laboratory. As with the first conference, the 2nd ACHV provides the unique opportunity to learn about the current activities of peers and colleagues and to exchange information on topics of interest such as human response, human modeling, experimental design, sensors, new technologies, and epidemiological studies of human responses to hand-transmitted and whole-body vibration. The conference organizers hope that the publication of these conference proceedings continues to foster new research and technological advances to reduce health hazards associated with occupational vibration exposures.

Jun 1, 2009

By P. James

"INTRODUCTION Control of target stream acidity is widely used in MIW (mining influenced water). Tailoring pH (a measure of acidity) finds application for controlling key chemistry in both process and waste streams. Traditional lime addition for neutralization and precipitation is most often used but has high reagent costs and results in large amounts of mixed metal sludge requiring costly disposal. A new adaptation of BPS’s patented DEMET™ technology (Dynamic Electrolytic Metal Effluent Treatment) platform offers a potentially improved and “reagentless” alternative to traditional chemical addition for pH adjustment. Electricity rather than chemical addition utilized in BPS’s proprietary approach controllably tailors target stream pH. The method offers a simple, low-cost processing technique yielding cleaner treatment chemistry. BPS’s “green” approach may yield lower operating (OPEX) and life cycle costs and significant reductions (up to 50%) in sludge generation compared to conventional lime treatment. It can also allow new opportunities to generate revenue via selective recovery of valuable processing byproducts. Specific savings and revenues depend on the target site chemistries, details, and processing goals. A more detailed discussion of the process and its operational principles may be found in Reference One.[1] Here application of the BPS treatment to POx (Pressure Oxidation) leaching as an alternative to traditional chemical addition is examined. An example operation process flow for gold mining is considered.[2] Promising processing points for potentially replacing conventional processes with DEMET are noted. The possibilities for lowering OPEX costs, lessening sludge creation, and capturing various valuable byproducts and residuals are examined. Financial life cycle benefit estimates of the principal gains provided by DEMET application to the example operation are noted. Extension and generalization of the analyses to a wider range of scenarios is explored."

Jan 1, 2016

Martin Marietta Aluminum, Inc. followed Howmet Aluminum Corp., Revere Copper and Brass, Inc. and Anaconda Co. in lifting August prices of 99.5 percent unalloyed aluminum ingot by 3 cents to 56 cents per pound. Prior to these moves, Kaiser Aluminum and Chemical Corp. raised its June ingot listings by 4 cents to 57 cents and Consolidated Aluminum Corp., 4.5 cents to 57.5 cents. Domestic merchants increased July quotes by slightly more than 1 cent to 51.3-51.8 cents per pound. ARSENIC The Occupational Safety and Health Administration (OSHA) issued new standards, effective August 1, for worker exposure to inorganic arsenic, a toxic substance linked by OSHA to lung and lymphatic cancer. The new standard will limit worker exposure to 10 micrograms per cubic meter of air over an 8-hour period, a drastic reduction from the previous standard of 500 micrograms for a like period. Implementation of the new standards may be the most difficult and costly for copper smelters where arsenic is associated with the copper feed material but problems will also be encountered by producers of arsenic containing products such as for pesticides and herbicides. The new standards allow use of personal protective gear for workers as an interim measure until plant engineering controls can be put into effect.

Jan 1, 1978

By Branch of Editorial Services

"The Bureau of Mines was established in the public interest to conduct inquiries and scientific and technologic investigations concerning mining and the preparation, treatment, and utilization of mineral substances; to promote health and safety in the mineral industries; to conserve material resources and prevent their waste; to further economic development; to increase efficiency in the mining, metallurgical, quarrying, and other mineral industries; and to inquire into the economic conditions affecting those industries. The organic act of the Bureau, as amended by Congress and approved February 25, 1913, made it the province and duty of the Bureau of Mines to ""disseminate information concerning these subjects in such manner as will best carry out the purposes of this Act.""In accordance with this directive, the Bureau reports the findings of its research and investigations in its own series of publications and also in articles that appear in scientific, technical, and trade journals; in proceedings of conventions and seminars; in reference books; and in other non-Bureau publications. The number of these reports, the wide range of subjects they cover, and the variety of mediums in which they appear make the kind of list and index presented in this special publication both necessary and valuable. This issue of the Bureau of Mines List of Publications and Articles describes reports and articles published during the period January 1, 1980, to December 31, 1984. It supplements the 50-year list of Bureau publications issued from July 1, 1910, to January 1, 1960;1 the 50-year list of articles by Bureau authors published outside the Bureau from July 1, 1910, to January 1, 1960;2 the 5-year lists of publications and articles from January 1, 1960, to December 31, 1964,3 from January 1, 1965, to December 31, 1969,4 from January 1, 1970, to December 31, 1974,5 and from January 1, 1975, to December 31, 1979;6 and the annual lists of Bureau publications and articles from January 1 to December 31, 1980,7 from January 1 to December 31, 1981,8 from January 1 to December 31, 1982,9 and from January 1 to December 31, 1983. 10"

Jan 1, 1985

By B. Genc

Safety in South African mines is a subject of significant interest, since many mining companies are experiencing production deficits due to safety-related stoppages. In this paper, safety data from the South African platinum mining sector is analysed for the period 2006 to 2010. The data was obtained from company annual reports as well as the Department of Mineral Resources, and analysis in the study is limited to injury and fatality data only. The overall safety performances of companies in the sector are compared, and opportunities for benchmarking and recognising potential sources of best practice amongst platinum miners are identified. Improving safety usually incurs a cost, and mining companies are particularly conscious of the importance of controlling costs. However, cost considerations often deal only with direct costs, and it has been shown that indirect costs are usually far more significant. Therefore, a greater safety spend will usually result in the creation of value for the mine since it will reduce the indirect costs associated with accidents. The results of some recent research in this area are presented. In this light, where available, the financial performances of mining companies in the sector, obtained from published annual results, are included in the benchmarking exercise to determine whether there is any correlation with safety performance.

Jan 1, 2012

By Douglas C. Corner

This is the first of a series of papers dealing with modern tunnel-driving methods, compiled in accordance with an outline prepared by engineers of the United States Bureau of Mines and to be published in a series of information circulars by the bureau. This series will supplement a similar and earlier series of papers dealing with mining methods and costs. ACKNOWLEDGMENTS The author desires to express hiss appreciation, of the assistance of A. C. Dennis, manager for the West Construction Co. Contractors, and Franc: E. Winsor, chief engineer for the Boston Metropolitan District mater Supply Commission who furnished much of the data and detailed description of operation appearing in the following pages. C. F, Jackson, mining engineer, United States Bureau of Mines, collaborated in the preparation and arrangement of the text.

Jan 1, 1931

By Christopher Mark

Sixty years ago, underground coal mining was the most hazardous job in the United States. Roof falls were a big part of the problem. They killed about 100 miners every year, more than all other causes put together. Fast forward half a century to 2016, which is the first year ever with zero roof fall fatalities. Just three miners were killed by roof falls during the following 6 years. How was this historic goal achieved? This paper starts with a modern analysis of the causes of the roof fall fatalities in 1968. Then it follows the reductions over time by category, using snapshots of the fatalities occurring in subsequent decades. Along the way, it evaluates the influence of the regulatory environment, changing mining methods, and better ground control technology. The paper shows that in 1968, more than half of roof fall fatalities at large mines were attributable to an inadequate safety culture. The immediate effect of the 1969 Coal Mine Health and Safety Act was to reduce the riskiest activities, like needlessly going under unsupported roof. Other hazards, like large roof falls, required technological developments before they were brought under control. Roof control plans, which the U.S. Bureau of Mines had been advocating since the 1920s, played a significant role throughout the process.

Jul 1, 2023

By David R. Wilburn

The U.S. Bureau of Mines investigated the resources, costs, capacities, market relationships, and short-and long-term supply of bauxite, alumina, and aluminum. The 45 evaluated mines and deposits in 14 market economy countries (MEC's) have a demonstrated resource of 8.4 billion mt of bauxite and an aluminum content of approximately 2.1 billion mt. Developed world bauxite resources and existing primary aluminum smelting and refining capacity are sufficient to satisfy demand through at least 1995, when additional properties (with higher cost levels) would need to be developed to satisfy future demand levels. It is anticipated that new alumina or aluminum production most likely would occur in developing regions with large bauxite potential, low-cost energy sources, and a close proximity to refining and/or smelting capacity. An increase in aluminum recycling capacity would help meet future demand increases. A series of network model supply analyses was performed for the period 1988 through 2000. Based on announced future production levels and assuming demand grows at the level outlined in the analyses, model results indicate there is sufficient material available to meet demand until 1998, where-upon an aluminum shortfall is projected. Additional analyses investigated the effect of a reduced growth rate of demand and regional production variations in Venezuela on the international aluminum industry.

Jan 1, 1993

Duties on Lead Imports from Mexico. - On September 15, the President signed Proclamation 4792 suspending concessions formerly granted as of January 1 on red lead imported from Mexico. The Proclamation also increased the duty payable on litharge imported from Mexico from 3% ad valorem to 3.5% ad valorem, effective September 15. Appeal of Lead Standards. - The U.S. Court of Appeals for Washington, D.C., rejected petitions by the Lead Industries Assoc. and St. Joe Minerals Corp. for a review of standards promulgated by EPA and OSHA. The Lead Industries Assoc. reportedly will appeal to the U.S. Supreme Court on the basis of the "benzene" and "cotton dust" decisions. Scheduled implementation of standards will continue during the appeal.

Jan 1, 1980

By Peter Amelunxen, Brandon Akerstrom

Since its introduction 40 years ago, the compartmental model of flotation has been used to predict the performance of mechanical flotation cells. However, it has found limited success for modeling dual-chamber machines and, as a result, engineers have adopted empirical correction factors usually derived from field audits of industrial cells to predict the performance of dual-chamber flotation cells. This paper introduces an extension of the compartmental model that applies to both single- and dual-chamber cells. The model is tested against pilot test work performed at Capstone’s Pinto Valley concentrator, and then used to evaluate the key operating and design parameters of dual chamber flotation cells. The results suggest that the design of the mixing chamber — for example, whether it is pneumatic or mechanically agitated — is not a significant contributor to overall machine performance. The work also suggests that the highest recoveries are achieved when the froth recovery is high, and longer separation chamber residence times and/or higher internal circulating loads are only beneficial when the froth recovery is low. Lastly, the results show that the single most important driver of the machine performance is the froth recovery of the separation chamber.

Mar 1, 2025

By K. Musgrave

"The ISO 9000 Quality Management System Standards have become internationally accepted as the way to manage quality assurance. The author has developed a Maintenance Management System Standard using ISO 9001as a model and is working with a major basemetal mining company to implement this. This paper describes the structure of the standard and the steps required for its implementation.Using a management standard ensures that a system is maintained, reviewed by internal audit, and when instances of failing to follow the procedures (nonconformances) occur, that corrective action is taken. It also ensures that regular reviews are made and that the sys-tem is continuously improved.The Standard is designed so that if an organization decides to register to an ISO 9000standard, the Maintenance Management System will be in a format that is compatible and can be incorporated with little effort into the Quality System.IntroductionIn reviewing maintenance operations at many mining companies, and often seeing those same organizations some years later, two recurring issues have been noticed..The first issue is how dependent effective maintenance is upon individual supervisors and crews. In one situation, a mine that had an excellent maintenance system in the 1980s. Now, with new supervisors and crews, it is starting to develop a system that will bring it back to where it once was. No written procedures remain from the earlier excellent system.The second issue is that most operations feel that maintenance is the sole responsibility of the maintenance supervisors and crews. Nothing could be further from the truth. Maintenance, like safety, is everyone’s responsibility. If the operator does not report problems and perform daily checks, and if the production supervisor runs equipment until it fails, then nothing the maintenance crew does will prevent emergency breakdowns and lost production. More importantly, equipment will be operated in unsafe conditions, putting employees at risk and, with today’s regulations, leaving supervisors open to prosecution.The Maintenance Management System outlined in this paper is designed to establish the present best practices as standard procedures, to provide a continual review so that these practices are improved in the future, and to identify instances where the system fails so that corrective action is taken. The mine referred to above is using this approach to make sure that, this time, the system it implements will survive."

Jan 1, 1997

By Jorge Armstrong, Sean Warren, JOSEF BOURGEOIS

The application of statistical analysis software programs has proven useful for the investigation of rockfall runout distance along a designed slope. Rockfall modeling programs are continually being upgraded with more sophisticated analysis tools, such as the use of the rigid body versus lump mass models. Engineers at mine sites utilizing the software may have varied experience related to these models, their associated input parameters, and how to interpret the generated results. To address this concern, researchers at the Spokane Mining Research Division (SMRD) of the US National Institute for Occupational Safety and Health (NIOSH) investigated the influence of slope height, slope angle, slope material, and rock size for both rigid body and lump mass models in a 2-D statistical analysis program. Based on a literature search and industry input, specific ranges common to that of an open pit mining environment were chosen for each of the input parameters to determine 90% rock runout distance as well as their sensitivity to change. Data collected from this numerical analysis and simulation will be compared to empirical rockfall data gathered through the duration of the Highwall Safety project conducted by NIOSH from 2022–2026.

Jun 18, 2023

By Kretschmar. U. H.

Fieldwork in the Meguma of Nova Scotia and Archean equivalents shows that bedding-parallel quartz lode gold veins (LVs) commonly occur at the top of graded elastic sequences. We define a "gold cycle" (GC) by analogy with Bouma turbidites and show that most "shear zones" and "lamprophyres" correspond to the upper pelagic-pelitic (E) division. We describe GCs from Archean Chester Twp, ON; Elmhirst, ON; Bourlamaque, QC; "intrusions" and interpret them as crystal tuffs and tuff-breccias. Extensive early Archean pyroclastic volcanism is implied: the genesis of trondjhemite-tonalite-granodiorite (TTG) rocks must be re-examined. The geopetal nature and asymmetric alteration of LVs indicates genesis from sea-floor hydrothermal vents. Textures suggest that often quartz was deposited as a gel. Vent geometry (fracture, point source or diffuse seep), bottom topography and vent spacing is reflected in wade-thickness plots. GC facing directions survive metamorphism. The Bourlamaque batholith was a flat-lying sheet of quartz-feldspar-hornblende crystal tuff, and isoclinal folding has repeated one or more gold-bearing horizons. Syngenesis clarifies and simplifies LV formation with major implications for models. Exploration becomes more cost-effective. Basin analysis, whole rock geochemistry, ore lens geometry and vent spacing can be used.

Jan 1, 2011

Norton Co., the world's largest producer of abrasives, is enlarging its proppant operation. Proppants are strong chemical particles used to wedge open rock formations in deep oil wells, thereby increasing the well flow rate, sometimes as much as tenfold. Norton" aluminum oxide-based proppant is rapidly displacing less durable materials. The company is building the world's largest proppant plant in Fort Smith, AR. ALUMINUM--See also REFRACTORIES The price of primary aluminum ingot was increased by several producers in July. Kaiser Aluminum & Chemical Corp., and Revere Copper & Brass Inc. increased the price of primary aluminum to 63.0 cents per pound, effective July I. Reynolds Metal s Co., Anaconda Aluminum Co., Howmet Aluminum Corp., and Marti n Marietta Aluminum Inc. increased the price of 99.5% primary aluminum ingot to 63.0 cents per pound, effective July 5, The Aluminum Company of America increased the price of aluminum ingot to 62.5 cents per pound, effective July 9. The range of prices at the end of the month was 58.5 to 63.0 cents per pound.

Jan 1, 1979

By William D. Monaghan, Michael A. Trevits

Over the period 2000 to 2003, roof falls have accounted for 4 to 14% of the fatalities in underground mining operations. The National Institute for Occupational Safety and Health (NIOSH) is conducting research to reduce the frequency, exposure, and risk of these events through an ongoing program of field and laboratory studies. One area of research involves the evaluation of polyurethane grouting technology that is commonly used to stabilize fractured mine roof strata. Concurrently, NIOSH is conducting work to evaluate the application of ground penetrating radar for advanced delineation of problematic mining areas. In this study, NIOSH partnered with Sub-Technical, Inc. who injected a polyurethane grout (also known as glue) into a roof area of NIOSH’s Safety Research Coal Mine. The mine roof area was scanned using ground penetrating radar technology before and after grout injection in an attempt to determine the extent of grout infiltration. A comparison of the pre-and post-grouting radar records showed a significant change at a mine roof depth of about four to five feet. The interpreted radar records were then compared with drill core information, borescope evaluation of roof-bolt holes in the study area, and underground observations. At this site, the interpretations of the radar records correlated with data obtained from the core holes, borescope evaluations and underground observations. This study showed that ground penetrating radar technology can be a useful tool for detecting changes in mine roof due to the injection of the grout.

By Andrea Brickey, JUDITH BUABA, RICHARD AMOAKO

The global mining industry has recorded significant declines in accident and injury rates attributed to the advancement in technology, increased enforcement, and safety consciousness. A goal of the mining industry is to achieve zero injury and occupational illness on all mine sites, prompting increased research into ways to further reduce mine accidents. A machine learning technique known as multiclass logistic regression is applied on a 10-year injury dataset from the Mine Safety and Health Administration (MSHA) to determine a miner’s susceptibility to a class of injury and to help identify significant risk factors associated with different classes of injury. The data is aggregated based on injury classification to provide statistically relevant results. The analysis identifies specific risk factors that influence a mine worker’s susceptibility to a given class of injury, i.e., non-fatal with no days lost or restricted activity, non-fatal with days lost and/or days of restricted work activity, and fatal and total permanent or partial permanent disability. These factors include miner’s age, mine type (coal vs. non-coal), experience on the current job (years), shift start time, employment type (operator vs. contractor), mining district, and type of accident. The results of the analysis indicate that a miner’s experience on the job, i.e., the number of years worked in a current job, is a significant risk to injury occurrence, even for those with decades of total mining experience. We further show the differences and similarities between the surface and underground mine incidents.

Nov 3, 2020

By R. C. A. Thurston

INTRODUCTION THE deleterious effect of stress raisers or notches on the resistance to fatigue of machine components, and other parts subjected to repeated dynamic loading, has been well known for many years. Most engineers in the mechanical field have, at one time or another, encountered a shaft which fractured due to a poor transition fillet, a holding-down bolt which failed due to insufficient tightening or inferior thread form, or a fitted member which broke through a combination of fretting corrosion and clamping stresses. All of these are examples of the damaging influence exerted by stress raisers in fatigue. Other common forms of stress raiser which have taken their toll of dynamic components are: keyways, oil holes, splines, quenching oil grinding cracks, tool marks, and sharp changes in section; some are the result of the design, others of poor execution of the design. It is our experience in the Mines Branch1 and I feel sure this will be corroborated by other fatigue investigators, that the majority of failures are due to incorrect design or faulty preparation of the part concerned, rather than to the use of inferior material. Quite frequently, it is true that the operating conditions necessitate the presence of a 'notch', but even in such cases methods are generally available by which its adverse effect on the life of the component can be reduced or annulled. The purpose of this paper is to discuss a few typical stress raisers, and to provide information on various processes for mitigating their effects in fatigue.

Jan 1, 1951

By M. F. Almeida

"Due to the randomness of all factors influencing the sintering operation, a two-stepped procedure is proposed to find the best way of using stocked fines at a plant producing Fe-Mn alloys for the steelmaking industry. The approach is based on the following: (1) predict the result of the sintering operation by establishing the best multilinear regression model using some of the characteristics of the loaded material; and (2) find the best solution under a minimizing cost criteria by solving a linear optimization problem using the regression equation plus constraints on the feed and product. IntroductionSome tests carried out using 20% to 30% of sinter in the material loaded into a 60 000 KVA Tysland-Hole electric furnace producing Fe-Mn alloys for the steelmaking industry indicated: (1) a meaningful decrease in the off-gas temperature and, consequently, a better energy use due to the material higher porosity; (2) more uniform heat distribution as a consequence of the electrode reaction zone enlargement; (3) an improved furnace control resulting in a smoother operation; and (4) a decrease in gas production facilitating the off-gas treatment. For some years, this plant used only the coarse fraction of the Mn ores, thus stocking all the received and own-generated fine particles. In view of the mentioned results, a strategy for increasing the use of stocked fines was formulated, including a step where it was necessary to decide which components and respective quantities should be used in the blends to be sintered (Almeida, 1984).It is well known that several factors affect productivity and energy consumption in sinter production, also influencing the product quality. Raw materials characteristics, namely chemical and size composition, affect permeability to gases and may or may not allow a deeper bed. In general, finer ores decrease permeability, increasing electricity consumption by fans, but due to their higher specific surface area, react more completely with other components in the mixture. For coke granulometry, a compromise must be obtained in order not to burn it too quickly nor to widen the flame front, therefore decreasing productivity. Decreasing coke in the blend also acts in sinter bonding, decreasing its consistency and increasing crushing and return fines. Moisture addition also influences components mixing, pre-agglomeration, bed permeability and, consequently, sintering productivity. Therefore, optimum conditions must be established for both a given sintering plant and the components in the feed (Dawson, 1993)."

Jan 1, 1998

By Donald F. Reed

During the first 6 months of 1948 the Bureau of Mines investigated the titania, deposit on the Wynn 0. Christy property in northern Hot Spring County, Ark. The property is situated in Magnet Cove, about half a mile north of the Magnet Store and U. S. Highway 270 (fig. 1). The purpose of the investigation was to determine the extent and grade of the ore body and to obtain a representative sample of the ore in as nearly natural condition as possible for use in metallurgical testing. All of the titania that has been marketed from Arkansas mines has been in the form of rutile from a deposit about 2 miles west of the Christy property. The titania in the Christy property occurs principally as brookite, which, with fragments of novaculite, quartz, and limonite, is imbedded in red clay. It is difficult to recover a core of the material. Three types of drills - a diamond drill, a bucket drill, and a Baker cable-coring tool operated on a churn rig - were employed in an effort to procure proper samples in their natural state. The Baker tool was found to be the most efficient and to be capable of drilling to a depth of 150 feet, making 80 to 100 percent core recovery (fig. 8). Total footage drilled was 1,536.9 in 21 holes, of which 7 were diamond-drill holes, 13 were bucket drill holes, and one was drilled with the Baker tool. The ore body was found to be 900 feet long, 500 feet wide, and more than 141 feet deep and contained 5.8 percent TiO2 and 0.52 percent 1720. Most of the deeper drill holes bottomed in ore, and there is a possibility that the ore may persist to a depth of several hundred feet. The Metallurgical Division of the Bureau of Mines is conducting experimental work at the Mississippi Valley Experiment Station at Rolla, Mo., for the purpose of developing methods of concntrating and utilizing the ore.

Jan 1, 1949