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The Bureau of Mines is establishing design criteria for effective roof support systems and is developing technology to improve mine planning and design. Geologic studies, surface and underground mine monitoring, and laboratory evaluations were conducted. The seven papers in this proceedings Information Circular present results of several investigations. Addressed are problems existing in both longwall and multiple-seam mines. Discussions include the effect of dewatering at a longwall mine site in the Pittsburgh coal seam and the effect of chain pillars on subsidence. Other results are measurement and characterization of longwall rock mass movement and an integrated design for stability in multiple-seam mining.

Jan 1, 1987

By Changwoo Lee, Jan M. Mutmansky

"This paper results from the research at The Pennsylvania State University into establishment of standard procedures for characterization of respirable coal dust performed by the Generic Mineral Technology Center for Respirable Dust and supported by the U.S. Bureau of Mines and the Mining and Mineral Resources Research Institute at The Pennsylvania State University. The research performed within this particular project is oriented primarily toward standard methods of sampling and characterizing respirable coal mine dust underground so that the chemical, physical, and morphological characteristics are known and can be related to the incidence of coal workers' pneumoconiosis (CWP) in Pennsylvania.The research was initiated by con¬ducting a search of the literature to determine what coal and geologic variables may be related to CWP. The effects of coal rank, free silica content, the mass of respirable dust, and the level of trace elements were the major variables studied. It seems to be evident that the free silica content, the rank of coal, and the mass of respirable dust are the major concerns in defining the causes of CWP. However, based on the literature survey, the authors have concluded that verification of the causes of CWP is a multivariate problem and must be analyzed in an appropriate statistical manner.The results of a multivariate analysis of ten trace elements recorded on Pennsylvania coals are presented. Five of these trace elements were found to be of use in differentiating one coalfield from the others. Of these five elements, chromium and zirconium showed a strong positive correlation with the rank of coal while strontium showed a negative correlation.The design of the field sampling work and its application in future research is the final topic discussed. The sampling plan is oriented toward continuous miner sections with eight-stage impactors as the collection equipment. All of the field work will be conducted in the coal measures of the Allegheny Formation and above with both dust and channel samples being collected in the same mines.Coal workers' pneumoconiosis has been an important topic of concern to miners, mining engineers, and epidemiologists for decades. The general cause of the dis¬ease, the inhalation of coal mine dust, is well known, but the specific coal and geologic variables that affect the incidence and severity of the disease are still subject to debate and study. The primary objective of this study is to identify those variables of Pennsylvania coals that contribute to the CWP problem. To accomplish this task, a field sampling program is to be conducted to relate the characteristics of the coal dust, the coal seam properties, and the geologic variables to the occurrence of CWP.The first year of this study has been involved with both a literature review and experimental work oriented toward identification of causal variables related to CWP. The results of this work are presented here along with plans for implementation of the findings in future research.The previous studies of CWP causal variables have been conducted by scientists, engineers, and medical personnel. Many different types of studies have been performed with emphasis on interpreting the effects of dust mass concentration, mineralogy of the coal, the rank of the coal, and trace element concentrations upon the incidence of CWP in various coalfields. Most of the research has been conducted during the last two decades, with the British Isles, West Germany, and the United States being the primary countries involved.The review of the literature was conducted to determine which variables are likely to warrant further study in Pennsylvania. Previous research studies have related CWP to free silica and other mineral content, the rank of coal, the mass of dust in the working place, and the trace elements in the coal and lung dust. In the following sections, each of these topics will be discussed and analyzed."

Jan 1, 1988

By Florence L. Feicht, Carlton E. Brown

"INTRODUCTION This report contains information on the approximate size of the smallest dust Particles revealed by or the limit of visibility of various microscopic systems. The information was obtained mainly for use in interpreting and evaluating results of number-contentration and particle-size, determinations on, samples of unhygienic particulate matter collected from industrial atmospheres and in developing better methods for determinations nations.Some speculation and even controversy have been published on the limit of visibility of the widely used microscopic system (16-mm., 0.25-or 0.3-N.A. objective, and axial light-field illumination) used in counting the dust in the liquid medium from impinger, 4/ 5/ filter-paper, 6/ and other samples, but little or no quantitative data have been published on the limits of visibility of this or other microscopic' system.ACKNOWLEDGMENTSThe interest, encouragement, and assistance received from H. H. Schrenk, chief of the Health Division are gratefully acknowledged, as is all other assistance received in this study."

Aug 1, 1945

By John C. Edwards

The Bureau of Mines developed a mathematical model to predict the oxygen requirements for a miner evacuating a mine. The model accounts for variations in the miner's escape speed with mine airway height, and for the empirically determined expressions for the weight-specific oxygen uptake rate for upright walking, stooped walking (duck-walking), and crawling. A Fortran computer program that is user oriented was prepared based upon the model's constitutive equations. Specific instructions for utilizing the program, as well as applications to miner evacuation from a mine, are presented.

Jan 1, 1986

By Fathi Habashi

"On August 3, 1888, German Patent No. 43977 entitled ""A Process for the Production of Aluminum Hydroxide"" was issued*. The discovery which led to the patent was made by the Austrian chemist Karl Josef Bayer (1847-1904) (Fig. 1) who was at that time in Russia, and the process became known as the Bayer Process in his honour(1)(2)- The process imediately achieved industrial success, displacing the pyrometallurgical process that had been used until that time to produce alumina. The Bayer Process involved the pressure leaching of bauxite with NaOH solution to obtain sodium aluminate solution from which aluminum hydroxide was precipitated by seeding. Today bauxite is not only the principal source of aluminum but also of gallium, both metals being effectively recovered by the Bayer Process. The purpose of this paper is to outline the historical background of this discovery and its importance to hydrometallurgy."

Jan 1, 1999

By N. Mashaba, D. Botha

The aims of this study were to investigate the factors that influence women’s engagement in technical positions in the South African mining sector and to determine what could be done to promote their successful participation. A convergent parallel mixed-methods research design was used to ascertain the factors that facilitate, inhibit, and influence engagement. In the quantitative phase of the study, questionnaires were circulated to women employeees; and in the qualitative phase, semistructured interviews were conducted with employer representatives, most of whom were human resource personnel. Confirmatory factor analysis showed that the three-factor structure (vigour, dedication, and absorption) of the Utrecht Work Engagement Scale fit the sample data reasonably well. Although there is room for improvement, respondents demonstrated acceptable levels of engagement in their work. On the other hand, the qualitative findings showed that employee engagement is impacted by unfavourable working conditions, work–life balance, and the mining industry’s male-dominated work culture. The findings showed that employee engagement should be elevated to a core human resource function. To increase the participation of women in mining, human resource professionals are encouraged to collaborate with mine supervisors, managers, and employees to develop programmes that promote employees’ absorption in and dedication to their work.

Nov 6, 2023

By Torma A. E.

Biotechnological processes are considered to be cost effective especially for situations where the recovery of metals from 'Very large volumes containing trace metal concentrations (less than 10 ppm) is concerned. Microorganisms, alive or dead, or their products can be highly efficient and selective biosorbents for metal concentration. It is important that the metal bound to the biosorbent can be stripped by suitable agent(s) and regenerated for repeated use. The stripped solution should be concentrated enough to be introduced into the common metal recovery circuit. The industrial acceptance of biosorption processes is dictated by increased competitive advantage over other processes. This paper reviews the pertinent literature?, regroups the information, and points out future possibilities for the mineral and metal processing industries.

Jan 1, 1992

By Johnson RW, Rogerson R

New perceptions of the nature of volcanic hazards on Bougainville Island have resulted from a recent remapping of the geology of the island. Ignimbrites and calderas have been identified at six Quaternary centres (Emperor Range, Tore, Kunua, Billy Mitchell, Loloru, and Laluai), and large-scale explosive activity now must be identified as a significant volcanic hazard on the island. Billy Mitchell and Loloru volcanoes are identified as the most likely sites of future, major, explosive activity. Billy Mitchell was recognised formerly as an extinct volcano, but is now known to have produced major eruptions 370 and 918 years BP. Five ignimbrite units recognised at Loloru range in age from about 12 700 to 3200 years BP. Bagana is an active volcano in central Bougainville, but its explosive activity is relatively minor and does not significantly affect areas beyond the uninhabited area of the volcano itself. Balbi is the largest volcano on Bougainville and has an extensive geothermal area at its summit. It was thought to have been in eruption last in the early nineteenth century. However, 370 and 940 year BP plinian ashfalls from Billy Mitchell cover the central area of Balbi, so the latest significant activity from Balbi may have been at least 1000 years ago.

Jan 1, 1990

By Valois R. Shea-Albin

Ground control problems are an important factor affecting safety, production, and efficiency in underground coal mines. A major portion of ground control problems encountered in underground coal mines can be attributed to geologic features in the strata surrounding the extracted coal seam. The U.S. Bureau of Mines has compiled information from numerous sources on the geological features that contribute to ground control problems in underground coal mines. The compilation includes (1) sedimentary features such as paleochannels, crevasse splays, clastic dikes, mold-and-cast structures, concretions, and lithologic factors, and (2) structural features such as folds, fractures, joints, cleat, and faults. The compiled information will aid in identifying the features, predicting their occurrence in advance of mining, and controlling or minimizing roof failure when these features are encountered in an underground coal mine.

Jan 1, 1993

By J. L. Workman

The Putnam Coal Mine, at design capacity, will be the third largest underground bituminous coal mine in the world and will feature the world's longest single flight belt conveyor. Construction is now in process; initial mining will commence in early 1969 and design capacity will be reached in 1971. The Putman Coal Mine reserves are located in south-central West Virginia and contain approximately 27,000 acres of prime Pittsburgh No. 8 coal; reserves are sufficient to support a 3.5 million tpy operation for over 30 years. The mine portal area is located some six miles inland from the Kanawha River. The river loading facility is located approximately 156 miles by way of river from the market.

Jan 1, 1969

By A. J. Kraemer

The twenty-fourth of a series of semiannual surveys pertaining to motor gasoline marketed in the United States was made by the Bureau of Mines in August, 1931. The first part of a report giving the results of that survey as they pertain to specification data is given in this paper. A companion report, Part II, is in preparation and will discuss the results of other determinations made on the samples, including octane number ratings on the individual samples (to be made by the Bureau of Standards) and results of the determination of gravity, color, doctor test, and "gum" content by the copper dish method and the Bureau of Mines steam-oven method. The retail price and the tax at the time each sample was taken will also be reported.

Jan 1, 1932

By S. Banisi, A. Haji-Zadeh, H. Asadi, M. Maleki-Moghaddam

One area in AG/SAG milling field which has received a great attention is the optimization of liner design for any application to increase the availability of mills. The Gol-E-Gohar iron ore concentration plant uses three 9m × 2.05m autogenous mills (AG) in parallel in a dry operation. The AG mill shell is lined with three series (57 cm each) of 36-row liners. Due to large variations in feed characteristics and inadequate blending, the performance of AG mills has been lower than the target value. Therefore, to improve the comminution efficiency, the optimization of the design of AG mill shell liners was applied in this plant. By simulation it was found that increasing the liner lifter face angle from 7 to 30° while maintaining the original lifter height (i.e., 22.5 cm) could provide an appropriate charge trajectory. Measurement of the wear profiles of shell liners indicated that the wear along the liner length was not uniform and the highest wear occurred between 0.5 m and 1.2 m of the mill length. A new liner design was proposed by redistributing the metal from parts with a lower wear rate to the parts with a higher wear rate to arrive at a uniform wear profile along the liner length at the liner removal time. The non-uniform shell liner was constructed and installed in one of the three parallel dry AG mills. It was found that the first and second liner designs increased the mill throughput by 2.6 and 7.5%, respectively. After conversion to SAG milling on the account of liner change, 18% (from 413 to 489 t/h) increase in throughput was realized. It was predicted that the non-uniform liner designs will increase the liner life time by 10% and will reduce the scrap metal from the current value of 59% to 50%.

Jan 1, 2014

The Cadia Mine is located 25kms South West of Orange in the central west of New South Wales (NSW), Australia (Figure 1). Orange is a major regional centre with a population of 35,000 people. Cadia has a history of mining and exploration dating back to 1851 and shortly after the first Australian gold rush at Ophir, north of Orange. Newcrest Mining commenced an exploration program at Cadia Hill in 1992. This identified a substantial zone of copper and gold mineralization. Subsequent resource definition drilling defined an orebody with a mineable reserve of 200 million tonnes of ore with an average gold grade of 0.74g/t and 0.17\ copper. A full feasibility study commenced in 1994, approvals to proceed with development were granted in September 1996 and the processing plant was commissioned in July 1998. The project came in on budget at A$440 million and on time, 24 months from design to construction. The estimated operating cost at the time of commissioning was A$8.85/t of mill feed.

Jan 1, 1999

By Edward F. Divers

Tills U.S. Bureau of Mines report briefly evaluates the advantages and disadvantages of basic dust control techniques presently used by U.S. coal preparation and mineral processing plants. These include ventilation, baghouse-type collectors, wet scrubbers, electrostatic precipitators, source control, sprays, good housekeeping, and personal protection devices. Two specific problems in these types of operations are also considered: dust collector system duct clogging, and control room dust control. Information provided in this report results from dust control research projects conducted by the Bureau at various coal preparation and mineral processing plants over the past decade to reduce workers' dust exposure. These studies indicate that plant ventilation systems normally provide the most cost effective method for dust control. Baghouses and scrubbers were also effective in specific applications, and examples of each are given. In extreme dust conditions, personal protection devices, such as respirators or the dust helmet, can also be highly cost effective.

Jan 1, 1990

By Oliver Bowles

"Score of the Bureau's Investigations.There has been outlined in a previous report* the results obtained regarding the adaptability of pulverized waste slate as a filler in road asphalt mixtures. As pointed out in that report the percentage of waste at slate quarries is very high, and the Bureau of Mines has undertaken the problem of discovering new and enlarged outlets for the waste material.Many products such as paper, rubber, road asphalt, floor coverings, paints, etc., require as one of their important constituents a considerable percentage of finely pulverized inert mineral matter to give ""body"", to obtain the desired consistency, or to supply the necessary wearing or other qualities demanded. Such materials are known as ""fillers"". The possibility that slate flour might be used as a filler with advantage in several products other than road asphalt led the Bureau to undertake further investigation.The Importance of Discovering Advantageous UsesIt has been found that in some products slate may be substituted for materials now in use without any marked effect on the quality of the products. A wider use of slate in such products could result only from a definite price advantage as compared with other fillers. Mile it is probable that waste slate may be placed on the market at prices which will encourage its wider use, it is evident that a waste slate utilization industry can never attain sufficient magnitude to definitely assist the slate producers unless it is demonstrated that some definite advantage in quality may be gained when slate is substituted for fillers now in use. The main purpose kept in view throughout the inquiry has been, therefore, to find advantageous uses for waste slate in order that both producer and consumer may be benefited."

Sep 1, 1921

By Paul Guliov

Potash dominates the industrial mineral scene in Saskatchewan accounting for 44% of total provincial mineral production in 1981. More than 7 million tonnes of potash have been produced annualy in recent years; ten underground mines are presently (1983) active. Sodium sulphate and cement are also important mineral products. Construction aggregates, clay products, bentonite, salt, peat moss and sulphur complete the list of industrial mineral products.

Jan 1, 1984

By Larry Dale

An approach for predicting the development of mineral resources on public lands has been developed as an aid to resource agencies. It consists of new techniques for evaluating the economic potential of the resource, the uncertainty about mine cost estimates, and the uncertainty about the occurrance of mineral deposits. New mineral sup- plies from inferred and hypothetical resources can be predicted by using these techniques. A case study illustrates their application in predicting development of copper resources in western Montana.

Jan 1, 1982

By David M. Gullikson

As part of its program of petroleum production research the Federal Bureau of Mines has long been engaged in the study and development of systems of analysis of oilfield waters (8, 12, 20, 21, 22, 27, 30).21 However, many of the early chemical procedures developed by the Bureau and widely adopted by the petroleum industry are time consuming, and some are unreliable for determining certain constituents found in California oilfield waters. Because of the need for more rapid and more accurate methods having greater sensitivity with low concentrations of some constituents, a study has been made by the Bureau's Petroleum Research Laboratory at San Francisco, in developing new techniques and modifying previously published techniques for analyzing oilfield waters by flame spectrophotometric, potentiometric, and colorimetric methods. Test solutions were synthesized for testing the suitability and accuracy of the procedures, and the effect of interfering ions. These solutions contained known quantities of characteristic constituents of oilfield waters including sodium, magnesium, potassium, calcium, lithium, strontium, barium, sulfate, chloride, bromide, iodide, carbonate, bicarbonate and borates in a wide range of concentrations. The compositions of these synthetic brines are listed in table 22. Many California oilfield waters contain salts of petroleum-derived organic acids and several synthetic oilfield waters also were prepared to which large quantities of naphthenates or salts of petroleum acids were added.

Jan 1, 1961

By Xiang-dong XING, Zhen-yang wang, Xing-le LIU, Jian-Liang Zhang

Experiments were carried out by adding CaF2 as catalyst in a Ar atmosphere to study the isothermal reduction kinetics of vanadium titano-magnetite carbon composite pellets under high temperature in the range from1473 to 1673K. By analyzing reduction mechanism, it was found that the rate controlling step was gas diffusion, and the activation energy was 178.39kJ•mol-1 without adding any catalysts. Adding CaF2 of 3% to vanadium titano-magnetite carbon composite pellets can decrease the apparent activation energy of reduction, and the decrease extent was 14.95kJ•mol-1. In addition, temperature is an important factor influencing on reaction rate.

Jan 1, 2015

By E. E. Ungar

The ways in which noise is generated and radiated by chutes and screens are described and corresponding noise control concepts are discussed. The amounts of noise reduction produced by applicable noise control means are delineated and generally cost-effective means are recommended. Available noise control materials and their applications are discussed. The results of field measurements, laboratory experiments, theoretical analyses, and studies of data provided by suppliers are summarized.

Jan 1, 1975