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By Richard V. Ageton

"Everyone admits that there are more accidents in metal mines than there should be but there is much difference of opinion as to the causes of accidents, whether avoidable or unavoidable, and the amount of responsibility attaching to the miner and the mine operator, respectively. However, it seems that one of the main reasons why there are so many accidents, is that there is so little general knowledge regarding their causes and costs. Some information regarding the costs and causes of metal-mine accidents is presented in this paper.The data contained were obtained from a study of the complete accident and medical reports of two large metal-mining companies, which carry their own insurance. Path maintain hospitals with competent medical attendants. One of these companies also maintains a very efficient safety bureau, consisting of a safety engineer, with two assistants who work in connection with the medical department, and with the safety committee made up from among the miners themselves.Daring the year of 1920, ""A"" Company employed approximately 900 men, and these men worked more than 270,000 shifts. There were 373 minor and major injuries, among these 900 men, hence assuming that each injured man was hurt cut once, 41 per cent of the men who worked in this mine received some kind of time-losing injury during the year. On account of these injuries the injured men lost 3731 shifts, and thus the time lost due to injuries amounted to approximately 1.4 per cent of the total number of shifts worked,"

Oct 1, 1923

By G. Dale Cor, Will H. Coghill, M. F. Williams, I. L. Feld

"INTRODUCTION During the past several years the Southern Experiment Station of the Bureau of Mines, with the cooperation of the University of Alabama, has given attention to hydraulic classification. One of the things this work has revealed is a variability not generally recognized in the conditions of teeter at different depths. This report depicts the passage of material through a teeter column and its emergence as a classified product.The work was made possible through the development of a classifier for several hundred pounds per hour permitting a small quantity of coarse spigot material to be discharged without the usual interruptions caused by stop-pages. Previous designs of small classifiers have been unsatisfactory because the,orifice used to control the quantity of spigot product as subjectto stoppages, particularly when attempting to discharge a small quantity of although the classifier used in this work has been described in detail in a previous publication 6/ its principal features will be discussed briefly herein. The main subject matter of the paper is based upon the three figures that illustrate in panorama the conditions that exist in a classifier during the continuous classification of bituminous coal, anthracite coal, and an iron ore trailing."

Jan 1, 1946

By John Dixon

This paper is one of a series on milling methods and costs being published by the Bureau of Mines. Acknowledgment is made to J. B. Tyrrell, managing director, and Wm. Sixt, manager of the Kirkland Lake Gold Mines, for permission to publish this article. The Kirkland Lake Geld Mining Co.'s mill is located on Government Road at the west end of the productive part of the Kirkland Lake mining area, 1 mile west of the village of Kirkland Lake. The crushing plant is connected to the shaft house of No. 2 shaft, which is now the only operating shaft.

Jan 1, 1931

By Walter I. Enderlin

To economically extract ore from great depths in the earth while sustaining an acceptable working environment will require the development of new technology and equipment, involving large capital expenditures. Moreover, careful analysis and advance planning will be required. But, the literature is lacking in data pertaining; to the thermal properties of various host rocks and to quantities of heat generated by various underground heat sources. This types, of data is required to forecast nine heat loads during advanced planning and design. This thesis sets forth a practical method for evaluating underground sources of heat in deep mines and provides an improved information base. Moreover, seven topics for further research are recommended. The heat sources considered are: wall-rock, ground water, adiabatic compression, equipment, service lines, blasting, metabolism, curing of cement, and oxidation of sulfides and timber. Seven deep metal mines with high production rates and high heat loads were visited to obtain data necessary to assess their thermal environments. Mine records were examined, wall-roc:, temperatures were measured and a survey of the mine ventilating air and mine drainage was performed. Also, the thermal conductivity of wet and dry specimens of the host rock were measured in the laboratory. Data analysis disclosed that rock heat and adiabatic compression account for stout 60 per cent of the mine heat load at depth. Equipment currently contributes approximately 20 per cent; however, to offset increasing costs with depth, increased mechanization is anticipated. The treat from ground water averages 19 per cent and the contribution from blasting, metabolism and cement is negligible. Also, approximately [0] per cent of the increase in the enthalpy of the ventilation air is in the form of latent heat. Moisture, however, did not significantly affect the thermal conductivity of the rock specimens measured in the laboratory. Also, from the data, it is evident that a negative correlation exists between the thermal conductivity of the host rocks and the per cent of the heat load derived from the wail-rock. Furthemore, steady state heat flow renditions may be assumed in airways where there has been no major changes in the ventilation system for a period of two years or more. Under these conditions, the author found it more convenient and reliable to compute heat influx using the steady state equation for heat flow into a cylinder, rather than Carrier's method for transient heat flow, which is so often used.

Jan 1, 1973

By Lloyd A. Morley

Research performed on computer modeling of mine power systems under USBM Grant G0155003 1S described. The work was performed at the Pennsylvania State University from 5 November 1975 through 4 November 1976. Results presented are interim in nature, and future research is planned to integrate the simulations which have been developed. The thrust of this research has been divided into three main areas. 1. Modification of a previously developed model (Mine Power System Simulation or MPSS) to include interactive operation and the use of default (average) load data. 2. Development of a dynamic simulation of interdependent mine power system induction motors. 3. Development of an approach to modeling of motor shaft loading of induction machines for mining operations. During the course of the current year's research, significant results have been achieved in all areas. Construction of an interactive MPSS model has been completed and checked. This simulation was written in APL code and is fully interactive. In addition, default data representing 158 different pieces of mining equipment has been developed for use with the interactive model. Additional work described includes the construction of a dynamic simulation of interdependent continuous miner induction motors and the development of an approach fo: motor shaft load torque computation from experimental data.

Jan 1, 1976

1. A total of 14,413 mining operations reported employment to the Mine Safety and Health Administration (MSHA). Nearly half (48.9%) were sand and gravel operations, followed by stone (28.5%), coal (14.7%), nonmetal (5.7%), and metal mines (2.1%). 2. Mine operators reported 240,000 full-time equivalent workers1 (down 3.9% from 1999). Independent contractors reported 42,000 full-time equivalent workers working on mine property (up 8.6% from 1999). Coal operators accounted for 26.8% of reported employee hours, followed by stone operators (25.9%) and sand and gravel operators (12.1%). 3. Eighty-four (84) work-related mine fatalities occurred in 2000 compared to 90 the year before. •The mine fatality rate was 29.8 per 100,000 full-time equivalent workers compared to a fatality rate of4.6 per 100,000 employees for all private industry. •Thirty-one percent (31%) of the fatalities occurred in underground work areas, which account for only17% of total employment. •Although the largest number of fatalities (28) occurred among miners who work for coal operators, coal contractor employees had the highest fatality rate (61.1 per 100,000 full-time equivalent workers). 4.There were 10,839 nonfatal lost-time injuries reported to MSHA, occurring at a rate of 3.8 injuries per 100full-time equivalent workers, and resulting in a total of 417,918 lost workdays.2 •Among all employees,3 the highest injury rate occurred among coal operator employees (5.6 nonfatal injuries per 100 full-time equivalent workers). •The highest percentage (34.7%) of nonfatal lost-time injuries were due to handling materials (e.g., over-exertion in lifting, pulling, or pushing objects), which also accounted for the greatest percentage of lost workdays (29.3%). •Among the most frequently occurring injuries, the most severe (as measured by the median number of days lost) were associated with accidents involving falls of ground, the use of powered haulage, and slips or falls. •The most frequently reported part of the body injured was the back (22.9% of all injuries). Back injuries accounted for the highest percentage of lost workdays (21.6%). 5.Seven hundred sixty-seven (767) cases of occupational illness were reported to MSHA. •The most frequently reported illness was repetitive trauma, resulting in joint, tendon, or muscle inflammation or irritation (37.3%). •There were 155 (20.2%) illnesses reported as hearing loss. The majority (68.4%) of hearing loss cases occurred among surface workers. •Coal workers' pneumoconiosis accounted for 14.5% of reported illnesses.

May 15, 2002

By James R. Boyle

The value of Alabama's nonfuel mineral production in 1983 was $361.3 million, an increase of $61.9 million over that of 1982. The increase reversed a downward trend that started in 1980 and established a new record high for value of nonfuel minerals in the State. Output of most nonfuel minerals increased to some degree with unit value increases creating the record-high value year. Cement, clays, lime, sand and gravel, and crushed stone were the major commodities produced in Alabama. Alabama led the Nation in the production of crushed marble; was second in bauxite; fourth in ferroalloys, dimension marble, common clay, and fire clay; fifth in bentonite and kaolin; and sixth in masonry cement and lime.

Jan 1, 1985

In spite of advances in measurement techniques and an explosive increase in the volume of research, our understanding of human strength remains in its introductory stages. It is clear that muscle strength is a highly complex and variable function that depends on a large number of factors. It is not surprising, therefore, that large differences in strength exist not only between individuals, but even within the same individual tested repeatedly on a given piece of equipment. The issue is compounded by the fact that correlations of strength among different muscle groups in the same individual are generally low, and tests of isometric strength do not necessarily reflect the strength an individual might exhibit in a dynamic test. As a result of these and other influences, great care needs to be exercised in designing, evaluating, reporting, and interpreting muscular strength assessments. Traditionally, tests of muscular strength were in the domain of the orthopaedist, physical therapist, and exercise physiologist. Such tests are also an important tool for the ergonomist, however, because of the high strength demands on workers in manual materials-handling tasks. In some cases, task demands may approach or even exceed the strength that an individual is voluntarily willing to exert in a test of strength. In such cases, evidence suggests that the likelihood of injury is significantly greater than when the task demands lie well within an individual's strength capacity. Because the relationship among strength capabilities, job demands, and musculoskeletal injury has been established, it is apparent that tests of muscular strength may benefit the ergonomist both in designing jobs and in ensuring that individuals have sufficient strength to safely perform physically demanding jobs. Several strength assessment techniques have been employed for these purposes, each possessing unique characteristics and applicability to job design and worker selection procedures. Our main purpose has been to elucidate these strengths and weaknesses, so that tests of strength may be properly applied in designing jobs and selecting workers. One of the crucial points we have emphasized is that any test of strength used in job design or worker selection must be directly related to the demands of the job.(1) For example, if an occupational lifting task has a high dynamic component, a test of isometric strength is not likely to provide the data necessary for proper design of the job. Of course, dynamic strength tests would also be misapplied in assessing a job requiring isometric exertions. Another potential pitfall is using tests of strength on isolated muscle groups and assuming that they are indicative of whole-body strength. For example, one might mistakenly assume that dynamic trunk extension strength represents a person's capability to perform a lifting task. However, an individual's lifting capacity may be entirely unrelated to trunk extension strength. It may, instead, be limited by an individual's arm or leg strength, depending on the task being performed. A final point on strength assessment should be made. An individual's strength capability cannot be considered a fixed human attribute. Strength training regimens can increase an individual's strength capability by 30%-40%. Whether

Jan 1, 1998

By J. J. Forbes

The Act of Congress authorizing the establishment of the United States Bureau of Mines became effective July 1, 1910. One of the most important duties Congress delegated to the Bureau in this Act was the study of health and safety conditions in the mineral industries. Early investigations of these conditions revealed the need of prompt Care of injured employees, as, under the difficulties inherent in their occupation, seemingly unimportant wounds if not treated promptly might become infected and cause permanent disability or even death. Many seriously injured persons brought out of mines and plants by fellow workers ignorant of approved methods of giving first aid or of safe means of transportation have been caused suffering and have had injuries accentuated to such a degree as to bring about permanent disability or death. The need of general instruction in first aid thus became apparent. BRIEF HISTORY OF FIRST-AID WORK The education of miners in the United States in first aid probably was conducted systematically first by the anthracite industry in Pennsylvania. Subsequently, first-aid training was carried on actively in Alabama and Indiana. Meanwhile, a general training campaign was carried on among industrial workers by the American Red Cross Society; when the Bureau of Mines began its nation-wide campaign of instructing employees of the mineral industries, the Red Cross turned over that part of its industrial training work to the Bureau but continued to cooperate by furnishing surgeons as judges in important first-aid contests and demonstr tions and assisted for a number of years in determining training methods.

Jan 1, 1937

By John C. Machisak

THIS INFORMATION CIRCULAR contains 1956 and 1957 injury experience and employment data for metal mines in the United States and Alaska. Unlike previous publications, this report covers only metal mining and contains statistical data on injuries and employment pertinent to metal mines and mills reporting voluntarily to the Bureau of Mines on an annual basis. Injury and employment data for the nonmetal industries, which from 1911 through 1955 were published in the same series as the metal industries, for the first time will be published separately as an information circular entitled "Injury Experience in the Nonmetal Industries, 1956 and 1957." The Bureau of Mines is authorized to make requests for injury and employment data, and the information submitted by operators of metal mines and mills is a step forward in promoting safety in the metal-mining industry. Every effort has been made to make this coverage as complete as possible.

Jan 1, 1960

By C. Melvin Lepper

Microseismic energy is generated when stresses accumulated in rock formations are released in the form of fracturing. The acoustic emissions resulting from these rock fractures and movements are detectable as velocity signals in the earth near the energy source. A Bureau of Mines microseismic system that is capable of detecting the acoustic emissions from pit slope movements is described. The digital circuitry incorporated in the system allows a microprocessor program to immediately calculate and present the location coordinates for the seismic energy source in the mine pit wall. This monitoring system is compact, portable, reliable, and relatively inexpensive and rapidly provides accurate information to the mine operators about the stability of a pit slope.

Jan 1, 1982

By Jack L. Henry, Davis E. Traut, L. R. Penner

The Bureau of Mines conducted solvent extraction batch tests to evaluate the usefulness of neodecanoic acid ( NDA) for extracting Co 3+ from ammoniacal leach liquors high in ammonium sulfate . This work is an outgrowth of previous Bureau research in which technology was devised for the recovery of cobalt , nickel , and byproduct copper from domestic laterites . The previously devised technology uses an oxidative ammoniacal sulfate leach to treat the laterite , and nickel and copper are then recovered from the leach solution by solvent extraction and electrowinning . This report deals with the subsequent solvent extraction of cobalt from the nickel - copper raffinate solution . The results showed that about 70 pct of the contained Co 3+ can be extracted batchwise at pH 8 using NDA ( a 10 - carbon - chain highly branched carboxylic acid ) . However , NDA had a solubility of approximately 0.6 to 0.8 g / L in aqueous raffinate following extraction , and this high solubility makes it impractical for use with alkaline solutions that are low in cobalt . In addition , the extracted cobalt species ( predominately cobaltic hexammine ) is not amenable to the electrolytic recovery of cobalt metal because of its extreme stability . This fundamental prob-

Jan 1, 1965

By D. A. Reynolds, J. D. Davis

"This work was begun in l928, with the cooperation of the American, Gas Association, and the Association contributed financial aid for that year and for the 4 years following. In 1933 financial aid was discontinued, but the Advisory Committee, under the able, Chairmanship of J. S. Haug, has continued to function through the years to the present date. Mr. Haug's annual reports have been published in the Proceedings of the American Gas Association. The purpose of this paper is to bring the index of coals tested by the Bureau of Mines-American Gas Association (EM-AGA) method up to date, to discuss development of auxiliary tests, and to outiline the uses to which the methods have been put in promoting the war effort.COALS TESTEDThe test methods developed with the advice of the Advisory Committee had been applied to 66 coals up to 1942, and an index giving the serial number, origin, and analyses of these coals was published as Bureau of Mines Technical Paper 637. Since this paper was published, 20 additional coals have been tested; the source and analyses of these coals are given in table 1. The table also refers to publications that have been issued. Complete series of tests at high, medium, and low temperatures,have been made on most of these coals, and blending tests with 20 and 30 30 percent of low-volatile coals have also been made at 900°C.; however a few low- and medium-volatile coals (60, 70, 74, 79, and 80) were bested,at high temperatures only. Those coals were mined in eastern Oklahoma and western Arkansas. The test work included low- and high-temperature assay tests, petrorraphic analyses, and plasticity tests since its inception; and for the last 20 coals of the series, expansion and oxidation tests have been made where applicable."

Jun 1, 1944

By R. V. Ramani, J. Qin, R. A. Jankowski

"Longwall mining is generally recognized as safer, more productive and economic when compared to room and pillar underground coal mining. There has been, however, increasing concern for the control of airborne coal dust concentrations in long wall faces. The airborne dust cloud at a longwall face is a complex aerosol system containing particles of varied size, density, shape and state of aggregation. For the development of more effective dust control practices in longwall faces, it is necessary to understand more clearly the characteristics of the longwall dust cloud.In this paper, results of a research study on dust concentration distributions along longwall faces are presented. The objective of this study is to characterize the longwall dust cloud behaviour and provide necessary fundamental data for a better understanding of the longwall dust problem. MSA personal samplers and gravimetric total dust samplers were employed to collect respirable and total airborne dust samples. The size distribution of these samples was determined by MicroTrac SPA. The instantaneous respirable airborne dust concentrations were recorded using RAM-I. The dust concentrations are related to face operations, particularly the shearer location and activities. The size distribution of airborne dust, instantaneous respirable airborne dust concentration, and air quantity distributions along longw all faces reveal a complex dust flow phenomenon. Additional fundamental studies are needed for characterizing the temporal and spatial behaviour of the dust cloud at longwall faces.IntroductionModern mechanized longwall mining was introduced in the United States in the 1960's and has become more common in the last twenty years. United States longwalls are multiple-entry retreating faces. According to a recent survey, 91 of the 102 longwall faces employ double-drum shearers (1). Several recently installed longwall faces have consistently produced over 4 000 to 5 000 tons per shift over extended periods of operation. The trend in under-ground coal mining in the U.S. certainly is toward the introduction of longwalls. This trend is true not only for new mines but also for renovation of existing mines. While longwall mining has many advantages over other mining methods, including improved safety, such as higher pro-duction. greater productivity and enhanced reserve recov-ery, it is associated with severe problems of dust control. The increase in longwall production has been accompanied by an increase in respirable dust problems which limit realizing the full potential of the longwall mining system. Despite the efforts to develop improved equipment and operational procedures to control the dust levels at longwall faces, it is still difficult to bring several double-drum shearer operations into compliance with the Federal stand¬ards of 2,0 mg/m 3 respirable dust without loss of produc¬tion. In fiscal year 1987, fifty-eight of the longwall sections were found to be in non-compliance once, and an additional 31 were cited two or more times'''. If the full potential of the longwall mining method is to be realized, new measures must be implemented to control the dust concentration to mandated levels. There is a need for detailed and extensive sampling of longwall faces to understand the dust source-sink relationships and the transient ambient concentrations. These must be related to the mining activities on the face. This paper is to characterize the longwall dust cloud behavior through a series of experiments in operating faces and provide necessary fundamental data for further studies to develop improved dust control practices."

Mar 1, 1992

By Robert S. Sanford

In April 1948, the Bureau of Mines was requested to evaluate the graphite deposit' known as the Benjamin Franklin and Just mines in Chester County, Pa. After preliminary investigation, it was recommended that the Bureau core-drill, trench, and sample the deposit and make beneficiation tests on the ore. During the first and second World Wars, flake graphite was in short supply, and a number of deposits in the United States were exploited. In 1942, the Defense Plant Corporation, through its lessee, the Benjamin Franklin Graphite Co., purchased 70.263 acres of graphite-bearing land and built a complete mining and milling plant with a capacity of 300 tons of crude ore per 24-hour day at a cost of $426,250 (Plancor No. 1254).

Jan 1, 1949

By Bernard Porter

Differential thermal analysis measurements were used to characterize a phase diagram for the KF-YF3 system at compositions between 0 and 60 mole-percent YF3, A congruent melting point compound was observed at 3KF?YFs, which melts at 965°±5° C and undergoes solid-state decomposition at 725°±2° C. One peritectic and two eutectic compositions are also defined.

Jan 1, 1969

By E. V. Potter

"INTRODUCTION The oscillator and amplifier system described in this paper was developed specifically for driving sound generators of the type developed by H. W. St. Clair and described by him in an article 3/ published several years ago in the Review of Scientific Instruments.Nevertheless, with little or no alteration it can be used to drive any vibrating system in which the vibrating member must be driven at its resonant frequency; the only restrictions are that the driving mechanism be electrical in nature and that the vibrating member be accessible so that some type of pick-up can be coupled to it. Operation of the automatic frequency-control element in the oscillator, however, depends entirely on the operating characteristics of the vibrating member; therefore, in order to completely explain the operation of the circuit, it will be necessary to describe the construction and operation of the vibrator used with it. Only the essential features and characteristics of the vibrator will be described in this article, and the reader is referred to St. Clair's 4/ report for further details."

May 1, 1943

By James R. Boyle

The value of Alabama's nonfuel mineral production in 1985 was $405.9 million, a slight decrease from the record high of 1984. With the exception of clays, output of most nonfuel minerals increased over that of 1984. Alabama was second in the Nation in production of crushed marble and bauxite; third in firre clay; fourth in masonry cement and kaolin; fifth in portland cement and lime; and sixth in ferroalloys and recovered sulfur, Alabama ranked 20th in the Nation in value of nonfuel minerals produced, but ranked 13th in value of industrial minerals. Valuewise, Alabama produced 2.4% of the Nation's industrial minerals.

Jan 1, 1987

By C. E. Hennig

On January 1, 1959, the United States had 313 petroleum refineries with a total installed crude-oil throughput capacity of 9,819,846 barrels per day, according to the Bureau of Mines annual survey. Compared with a year ago, this represents a net decreased of five in the number of slants mild a net increase in capacity of 412,139 barrels per day. The continued increase in total capacity and decrease in number of plants raised the average capacity of a refinery to a new high of 31,373 barrels per day. During 1958 total capacity increased in every refining district except the Louisiana Gulf district, which showed a 2-percent decrease due mainly to the retirement of the American Oil Company's plant at Destrehan, La. The largest increase, 14 percent, occurred in the Texas Inland district followed by a 12-percent increase in the Arkansas-Louisiana Inland district. At the beginning of 1959 the industry was building facilities that would add 108,400 barrels per day to crude-oil capacity. It also had under construction a capacity of 226,100 barrels per day as replacement. On January 1, 1959, no new refineries were under construction.

Jan 1, 1959

By Gary R. Gavan

This report presents the documentation and User's Manual for a data retrieval and report generation computer program. The program operates on a data base containing over 19,000 pieces of coal mine equipment in use in 1976.

Jan 1, 1979