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By S. J. Pearce

One phase of the work of the Bureau of Mines in health and safety is promotion of the use of safe, satisfactory, and reliable respiratory-protective devices. To insure that such devices will be available, the Bureau has established schedules of minimum requirements for self-contained breathing apparatus,3/ gas masks,4/ supplied-air respirators (hose masks, air-line respirators, and abrasive-blasting helmets, hoods, or masks),5/ dispersoid (dust, fume, and mist) respirators,6/ and nonemergency gas respirators (chemical-cartridge respirators).7/ Approval tests of self-contained breathing apparatus are conducted under the supervision of mining engineers of the Accident Prevention and Health Division} Region VIII; approval tests of other types of respiratory-protective devices are conducted by the Health Branch.

Jan 1, 1952

By John C. Cook

Channel sand bodies ("wants" or "cutouts") are deposits of barren, hard sediments which interrupt production and pose safety hazards when encountered in underground coal mining. To locate these costly impediments to mining in advance, from the surface of the ground, the seismic reflection method is recommended. High-resolution (high frequency) techniques for shallow seismic exploration of coal beds have been worked out and are reported here, including a field example. Newly-developed high-frequency, digital recording equipment was used, together with light-weight shot-drilling equipment and a variety of down-hole seismic impulse sources. Techniques for rapid but complete coverage of a coal prospect area with a crew of 2 to 6 men n 2 or 3 vehicles are described in detail.

Jan 1, 1976

By W. A. Toohey

Introduction From the earliest times it has been an inherent trait of man to build or create something for his own use or convenience. The need of some form of shelter other than that of the caves led him to bind together stones and other materials to form walls for his abode. Moistened clay which hardened upon drying was no doubt first employed. The Assyrians and Babylonians appear to have employed it or the bitumen found in their country. The early Egyptians and Greeks used some form of lime in their construction work. In addition to these shelters, other structures received attention, and, long before the Roman Empire was established, the Carthaginians made use of a natural cement as binding material. Portions of an aqueduct, seventy miles long, in Northern Africa, built in those early days, are still in use. The Etruscans were the first people in Italy to employ a mortar in their buildings. The Romans, learning the art from the Etruscans, improved the mortar by using a mixture of lime and volcanic ash, called 'puzzolan', and built not only roads but those famous structures, the ruins of many of which exist to this day. The Pantheon at Rome, built by Hadrian about 120 A.D., is perhaps the finest example of the early use of cement in building construction. With the decline of the Roman Empire, the art of making cement seems to have been lost, and for centuries the builders of Europe used only lime mortar. Pure limestones were selected for making the lime and great care was taken in the preparation of the mortar, the supply for one year being made the previous season and left to thoroughly slake or 'ripen' in pits covered with earth. The mortar thus produced gave excellent service above ground or where it was exposed to the hardening action of the air, but would not harden under water.

Jan 1, 1927

By J. A. Holmes, EDWARD C. FRANKLIN, RALPH A. GOULD

The commission may be permitted to express its earnest hope that the litigation which comes to an end with the findings and recom- mendations herein set forth will be considered by both parties to the action as definitely and equitably decided. The commission trusts that its work will show the value of the commission form of settlement and that its work will serve as a prece- dent to be followed in disputes relative to technical subjects. If the work of the commission is productive of a tendency on the part of technical litigants to avoid the use of the courts for the settlement of disputes it will not have been done in vain. Such tendency will surely grow and ultimately such differences will be arbitrated by technically trained men without recourse to the courts of law. Appended to the report of the findings of the commission are to be found the detailed reports covering the several lines of inquiry and investigation carried on by the commission and upon which its findings are based, and also a detailed statement of the fiscal affairs of the commission. A word of explanation is necessary in regard to the fiscal statement. While each party to the litigation has agreed to bear one-half of the expense of the investigations of the commission, it will be noted that the Selby Smelting & Lead Co. is credited with $21,000, while Solano County is credited with but $6,000. In order that the investigations of the commission might go forward without interruption the Selby Smelting & Lead Co. has generously supplied funds at the times they were needed. This assistance has been

Jan 1, 1915

1. Domestic Production and Use: In 1978, 12 companies operated 31 primary aluminum reduction plants, with 3 firms accounting for 65% of production capacity. Washington, Oregon, and Montana accounted for 31% of the total capacity; Gulf Coast States 23%; Northern States 26%; and other Southern States 20%. Based on published producer prices, output of primary metal in 1978 was valued at $5 billion. Aluminum consumption by 25,000 firms was centered in the East Central United States. Of aluminum consuming industries in 1978, building accounted for about 25%; packaging 22%; transportation 23%; electrical 11%; consumer durables 8%; and other uses 11%.

Jan 1, 1979

By Elham Kordzadeh

As the world’s reserves of coarse and high-grade iron ores continue to shrink, beneficiation is becoming increasingly important. The resulting concentrates cannot be used directly as feedstock for iron making, but require an additional agglomeration step. Pelletizing is preferred, because the uniform chemical, physical, and metallurgical characteristics of pellets make them a more desirable feed for the iron making processes. The heat hardening or induration of pellets is typically done in shaft furnaces, grate-kiln systems or on straight grates. Rotary kilns were originally developed in the late 19th century for Portland cement production [1]. The main development work for the successful adaptation of the process to the thermal treatment (induration) of green balls from iron ore was performed by Allis Chalmers in Milwaukee, Wisconsin, USA in the 1960’s [2].The straight grate process, which was first used in 1955 at Silver Bay, Minnesota, was a dedicated development with the aim to pelletize and indurate magnetite (taconite) concentrate [2]. There are various important technical and economical distinctions between the two pelletizing technologies. The most important differences include that a grate-kiln has three distinct pieces of equipment, a preheat grate, a rotary kiln and an annular cooler, whereas in the case of a straight grate, the entire indurating process is done on one piece of equipment only. In addition, both technological solutions have differences in their recuperation systems, direction of air flow in drying, number of burners, form of pellet movement, etc., which cause differences in raw material suitability, process control, economical aspects, plant operation and product pellet quality.

Oct 30, 2017

By C. E. Julihn

In the fall of 1933 a new discovery of gold was made in the old Mojave mining district of California about 70 miles north of Los Angeles. It led to mining operations that have surpassed in their results all reasonable expectations and are of exceptional promise for the future. In less than 3 years, exploration has opened up a number of veins, from some of which a substantial amount of high-grade ore has been shipped, while a large tonnage of milling ore has been disclosed. Two mills, operating on ore averaging better than $12 a ton, will probably produce more than a million dollars worth of gold in 1936, and a considerable increase of their output in the following year is anticipated. While continuance of these operations for a number of years is already assured by ample reserves of ore, future discoveries of still other veins are reasonably possible, as occurrence of gold throughout the volcanic rocks of the district is widespread and the veins now being mined showed little to attract attention at the surface.

Jan 1, 1937

By D. E. FOCG, A. E. Wells

When the United States entered the World War governmental agencies found little definite knowledge available as to the exact capacity of each sulphuric acid plant in the United States to manufacture acid under the stress of a great emergency. It is true that on account of the demand for acid for the manufacture of munitions for the Allies, prior to the entrance of this country into the war, most of the acid plants near industrial centers in the Eastern and Northern States were running at or nearly their maximum capacity, but, . for various reasons, many plants in these States and plants in other districts were not. For a number of years statistics as to the production of acid by the plants of the country were compiled by the United States Geological Survey, but obviously such figures did not give information as to the maximum capacities that might be available for meeting the he.a vy war ·requirements, or as to the steps that would have to be taken to bt-ing these capacities into use. During the summer and early fall of 1917 various attempts were made to obtain the desired information, but no satisfactory or complete data were obtained. Late in 1917, under the authority granted to the Bureau of Mines by the explosives act, the Director of the Bureau of Mines directed A. E. Wells, metallurgist of the bureau, to uiake a complete survey of the situation. Mr. Wells personally conferred with officials of the acid companies and visited most of the acid plants in the North that are east of the Mississippi River. The information obtained through this personal survey, together with that obtained through the ready cooperation of the subcommittee on ncids, and the subcommittee on fertilizers of the Committee on Chemicals of the Council of National Defense, enabled the preparation of a report containing the desired data concerning the sulphuric acid industry. This report was made immediately available to the War Industries Board and to those offices in the War and Navy Depart- ments that were most directly concerned in planning the explosives program and in obtaining the necessary supplies to produce the explosives. Beginning with this survey and report, the sulphuric acid section of the war minerals investigations of the Bureau of Mines took an active part in all matters pertaining to the sulphuric acid industry during the remainder of the war. Mr. Wells, the chief of the section, was appointed an associate chief of the sulphur, pyrite, and sulphuric acid sections of the War Industries Board. .Also, by this direct contact with the War Industries Board, the data obtained by Messrs. R. R. Hornor, H. A. Buehler, a.nd 0. Lindstrom, who were in charge, for the bureau, of the investigations concerning the supplies of pyrite and sulphur, were constantly made available to all interested Government agencies. D. E. Fogg, of New York City, was appointed chemical engineer to the sulphuric acid section to make special investigations relating to the acid industry, especially the possible utilization, in an emergency, of those sources of raw material.not then being used. Mr. E. E. Corbett, of Brooklyn, N. Y., was appointed chemical engineer to make investigations concerned primarily ,vith the conservation of acid. Direct and intimate contact with the industry was had through the close cooperation with the committee on acids of the Chemical Alliance, this committee during the greater part of 1918 occupying rooms with the acid section of the bureau. With the ending of the war and the close o:f the active work of the acid section of the bureau, the suggestion was made by many interested parties that a bulletin be prepared giving some qf the fun. damental and most important facts regarding the sulphuric acid industry, including a discussion of the technical :features of the manufacture of acid. During the war the bureau received -a vast number of inquiries in regard to various phases of the industry, a.nd this fact also made such a bulletin seem desirable. Therefore, the present bulletin was prepared to cover the main facts in regard to the industry in this country, including a discussion of the supplies of sulphur-bearing raw materials, the situation of the acid plants, the principal points in regard to manufacturing processes, and the uses of the acid. No attempt has been ma.de to discuss at length the manufacturing processes, as details differ more or less at the different plants and in general are carefully guarded by the acid ·companies. A great deal of the data given in this bulletin may be found in various pub]ications, but this is the first publication in which such data have been assembled and made readily available. Most of the data were obtained directly from observation and from cooperating acid companies or from individuals who had been or are now engaged in acid manufacturing and were liberal and generous in making their information available for publication. Care has been exercised to publish no data that were obtained as confidential by the bureau's representatives. The average acid manufacturer may be already more or less acquainted with most of the information presented in this bulletin, yet it is believed that the bulletin will be of value to those who wish to obtain a. general review of the present condition, both the economic and technical, of the sulphuric acid industry in the United States.

Jan 1, 1920

By John A. Kost

Control of the dust produced by continuous mining machines in coal mines is conventionally attained by water sprays from fixed nozzles mounted on the frame of the machine behind the cutting head. In the tests conducted under this contract a so-called "wet-head" machine was used, where the spray nozzles were mounted on the rotating head itself, close to the coal-cutting bits. The tests were conducted at the Robena Mine of U.S. Steel Corporation, using Lee-Norse machines. Operating the wet-head machine and a conventional spray machine in turns in the same section, it was found that the wet-head produced approximately 25 percent less respirable dust and 60 percent less total airborne dust than the conventional spray machine. The wet-head also greatly improved the visibility of the cutting bits from the machine operator's position. Several difficulties had to be overcome before any meaningful tests could be conducted, including excessive pressure drops in the piping system and plugging of the nozzles from internal water contamination. The major obstacle, however, was the rotating water seals on the wet-head, which leaked excessively after only a few hours of operation. Only after several changes and plant and laboratory tests was a design found which permitted conducting the underground tests without appreciable water leakage.

Jan 1, 1976

Jan 1, 1966

"The Cooperative Research Centre for Mining Technology and Equipment (CMTE) is funded by the Commonwealth Government, by its mining research members — the Universities of Queensland and Sydney and the CSIRO1, and by its industry members — BHP Coal, RioTinto R&TD, Hamersley Iron, Mining Technologies Australia, Pasminco, Shell Coal, WMC Resources, Advanced Mining Technologies, and Aberfoyle. The Centre conducts work aimed at improving the competitiveness of the Australian mining industry. The current work is focused in four areas: new mining and drilling systems, geological sensing, automation, and equipment maintenance and reliability. This paper describes much of the work in these program areas that relates to metalliferous mining. Mechanized Rock ExcavationThe disadvantages of the drill-and-blast excavation method are widely recognized and the last half of the 20th century has seen mining companies and mining research organizations aggressively pursue technology to excavate rock by other means. As discussed below, despite considerable effort and large amounts of funding, the quest for mining’s “Holy Grail” has been unsuccessful in all but the weakest rock types.COMRO (the Chamber of Mines Research Organisation) supported by the South African gold mining industry, spent three decades and (probably) tens of millions of dollars developing prototype drag bits and, later, impact breaking machines aimed at the mechanized stoping of narrow, tabular reefs. This work has not yet produced a commercially-attractive mining system. Work continues in South Africa to mechanize these stoping operations although now the emphasis is on the use of diamond-wire sawing techniques. This work remains in the experimental phase.Both British Coal and Germany’s Bergbau- Forschung spent many years developing techniques trying to extend the range of rock types which roadheaders could cut economically. Again, although new knowledge was produced, it is difficult to claim that any new commercial mining systems emerged from this work."

Jan 1, 2001

By Robert Torbin

The objectives of the Continuous Shaft Lining (CSL) System are to reduce the costs, safety hazards, and time currently required in lining mine shafts with concrete. The CSL will line machine bored shafts downward from the shaft collar on a continuous basis using an inverted, pressurized slipforming technique. The technique for slip-forming downwards has been demonstrated and refined under this program. The approach taken involved laboratory scale testing of key features of the CSL concept. These feature tests included concrete distribution, concrete sealing, concrete slipforming and development of a reliable concrete mix. Based on these results, a full scale above-ground test facility and CSL were designed and fabricated. The objectives of these tests were to demonstrate the viability of the basic concept; to establish operating limits; and to provide input data and information for the design of a second generation shaft lining system. The results of the program have led to a CSL design and operational philosophy which will need to be tested in an underground environment before industry will accept the technology. However, the next generation CSL promises to meet all the original program technical objectives.

Jan 1, 1983

By BUREAU OF MINES

Atentative Draft of a standard smoke abatement ordinance has been prepared by a joint committee made up of representatives of the American Society of Heating and Ventilating Engineers, the Stoler Mamufacturers Association, the American Civic association, and the Fuels Division of the American Society of Mechanical Engineers. The Committee is desirous of obtaining helpful criticism and suggestions about this ordinance, which should be mailed to the chairman, Dr. O. P. Hooi, Bureau of lines, ashington, D. C. Te personnel of the committee is as follows: Dr. O. P. Hood, chairman, and Henry Kreisinger, representing the Fuels Division of the American Society of Mechanical Engineers; P. J. Dougherty, representing the American Society of Heating and Ventilating Engineers; Lloyd R. Stowe, representing the Stoker Mam- facturers Association; Everett L. Hillard, representing the American Civic Ascociation; and Osborn Monnett and Harry 3. Meller, members at large.

Mar 1, 1930

By Ronald Althouse

During the past five years under contract with the U. S. Bureau of Mines (BOM Contract J0308002). West Virginia University's Mining Extension Service (WVU-MES) has designed, developed) and delivered to the mining industry a comprehensive training program for Mine Rescue (MR) teams and a management planning tool for Mine Emergency Preparedness. The Mine Rescue team program is systematically built on a set of training objectives, backed up by content, allowing mine operators to conduct team training activities. These materials are user-ready, provide the MR principles and practices for both initial and advanced training, and supply teams with exercises geared to problem-solving activities. In addition to an instructor's program guide, the eight (8) modules that comprise the initial (20 hour) MR training are: an Introduction to Mine Rescue, an Introduction to Self-Contained Breathing Apparatus (SCBA), a set of modules covering each approved minimum 2-hour SCBA (i.e.) the Draeger BO 174-A. the McCaa) the Aerolox. & the Scott Rescue-Pak), and a manual on Auxiliary Apparatus as well as the Chemox Auxiliary SCBA. Advanced, annual refresher training (40 hour) is covered by seven (7) modules that spell-out the principles and practices needed to establish surface organization, to handle mine gases as well as mine ventilation, to conduct exploration, for fires, firefighting, and explosions, to rescue survivors and recover bodies, and to accomplish a mine recovery. Approved by MSHA in 1984 to meet requirements for 30 CFO. Part 49, these materials provide a basis for trainers' instruction, for comparison of team capabilities, for modifying programs resources, and services, and for program planning. The Mine Emergency Preparedness Program (MEPP) is used by management as a tool in the preparation of company personnel for handling a mine emergency operation. As a wholly new program. MEPP depends upon development of a Mine Emergency Organization and Emergency Operations Procedures. It also requires regular scheduling of drills) periodic mock emergencies, and evaluation of organizational responses and program performance beyond required training of mine rescue teams. MEPP materials are arranged into three sets of guides: 1) the Preparedness Program System Guides include an Executive Summary, a Program Director's Guide Mine Emergency Organization, and Emergency Operations Procedures; 2) the Emergency Organization (MEO) User's Guides cover the Rescue and Advisory Division, the Technical/Safeguarding Division, and the Surface Support Division; and 3) the Emergency Procedures (EOPS) User's Guides detail Containment Level Procedures, Notification Level Procedures. Mobilization Level Procedures, and Deployment Level Procedures.

Jan 1, 1986

By John T. Dieckmann

This report documents the work performed and the results obtained in a 2-year development of a Mobile Inert Gas Generator for use in the Bureau of Mines Remote Sealing System for fighting underground coal mine fires. The performance requirements of an inert gas generating system for the Remote Sealing System were clearly established. A thorough review of seven possible system designs meeting these requirements was conducted. An air cooled, distillate oil fired combustion type inert gas generator was selected for further detailed design, hardware fabrication, and performance testing. The Inert Gas Generator constructed under this program has been thoroughly performance tested and has been operated in the field for approximately 200 hours. The system has met or exceeded all important performance requirements. The system was used in the fire fighting efforts at the Bethlehem Mines Corporation Cambria Division Mine 33 fire and contributed to the successful containment of the fire. The system was also employed in the demonstration of entire Remote Mine Sealing System at the Jenney Mine in the fall of 1978. The system is currently avail-able for fighting any future underground coal mine fires.

Jan 1, 1979

By Spencer P. Howell, Munroem Charles E.

"Introduction;As in the case of TNT previously presented*, this report presents the results of an investigation to discover the safest and best way of utilizing picric acid for industrial blasting purposes. It describes the physical and chemical properties of this explosive, gives precautions to be observed in handling, packing, preparation of cartridges, and holes, presents the results of field tests in blasting stumps and bowlders, and compares the results with those obtained from dynamite.The investigations reported herein were undertaken and this paper has been prepared, solely to aid in the salvage of the surplus picric acid accumulated for war uses and released by the declaration of the armistice. No funds were available nor have any been appropriated with which to defray the expense of converting this picric acid into any other form or to prepare any explosive mixture from it. The sole problem was to find appropriate uses for this military picric acid in existing needs and to show that it can be efficiently used in carrying out essential civil projects.It is not intended by this publication to promote the use of picric acid as an industrial explosive further than is necessary for the proper utilization of this surplus. On the contrary, the authors believe that picric acid by itself is unlikely to come into general use as an industrial explosive, chiefly because of its cost but also as shown by the clouds of smoke it emits on explosion and the nature of the reactions it undergoes because we do not obtain from it its highest efficiency. As demonstrated in its previous use in Joveite, better results and higher efficiencies may be obtained by mixing picric acid in proper proportions with sodium nitrate or ammonium nitrate, to more completely oxidize the picric acid, and another nitrosubstitution compound, such as nitronaphthalenes, with which do desensitize and waterproof the composition formed. By such admixture not only may the energy resident in the picric acid, be more fully utilized but the cost of the resulting blasting explosive should be much less than that of picric acid."

Apr 1, 1921

By Raja V. Rarnani, Robert L. Frantz

"The more than 75 research projects funded throughout the first 10 years of the Dust Center's operation have resulted in numerous cumulative findings fulfilling the goals of the Center. These project descriptions present the methodologies and project-to-project relationships leading to their various accomplishments and demonstrate the mesh between project objectives and Center goals.To develop equipment for collecting respirable dust samples.To develop experimental methods for particle-by-particle characterization of morphology, size, and chemistry.To develop experimental methods for overall respirable dust sample characterization of size distribution, chemistry, and crystallography.The project directly addresses the Center's goals to enhance the understanding of the scientific and engineering characteristics of fine and respirable mineral particles found in mining and milling atmospheres and to establish the relationship between natural and cultural factors (mine geology, mineralogy, mining and milling methods, equipment, and control measures) in the generation of fine particles. The project also aims to contribute to the development of control mechanisms for reducing ambient respirable dust concentrations and worker exposures.The work on this project is related to similar work on Coal Mine Dust Characterization (Project No. 2701/MN1) and Characterization of Dust Particles (Project No. 4203/PS3).Airborne dust sampling was performed at the following locations: 1) a sand and gravel quarry in Southern New Hampshire, 2) a welding facility, 3) a ceramic powder facility, 4) a metal powder facility, and 5) the air in Cambridge, Massachusetts. A portable sampling box incorporating two Sierra personal cascade impactors was designed and produced. At a 2-LPM flow rate, the effective cut-off diameters of the Sierra impactors were 10.0, 6.0, 3.5, 2.0, 0.9, and 0.5 mm, respectively, for each stage, and the air passed through a PVC filter after the last stage. In addition, the sampling box contained a total respirable dust filter. The substrates were weighed carefully before and after collection, and the weight increases were recorded. All films, foils, and filters were put in the balance chamber for more than 8 hours to stabilize the temperature and humidity before weighing. A Cash 21 microbalance (±0.001 mg) was used to weigh the Mylar films, SS films, and filters."

Jan 1, 1995

In 1960, the Secretary of the Interior, acting under the provisions of Public Law 454, 80th Congress, appointed a Lignite Advisory Committee to aid in programming research on coal (lignite) of the north-central area. The chairman of this committee is the Secretary of the Interior or his delegated representative, and in all meetings held during 1960 and 1961, the Director of the Bureau of Mines, Marling J. Ankeny, has presided. The members of this committee were R. W. Rovelstad, President, Baukol-Noonan, Inc., Noonan, N. Dak. W. E. Keller, Vice President, Northwest Division, Truax-Traer Coal Co., Minneapolis, Minn. A. M. Cooley, Professor of Chemical Engineering, University of North Dakota, Grand Forks; N. Dak.

Jan 1, 1963

By C. M. Diaz, P. J. Mackey

Since its inception, in 1987, the Copper-Cobre series of conferences has established itself as the prime world forum for discussing advances in copper process metallurgy, in particular copper sulfide smelting, copper recovery by leaching and electrowinning and copper electrorefining. All copper producing countries have actively participated in the pyrometallurgy symposia held in the framework of these conferences. In 1999 and 2003, the close to 100 pyrometallurgy papers that were presented had to be accommodated in two volumes. In the present paper, the authors firstly provide a brief historical sketch of the Copper-Cobre conferences and then focus on providing a retrospective look at the dramatic changes that have taken place in copper smelting in the last few decades, primarily as discussed in the Copper-Cobre and precursor conferences pyrometallurgy proceedings. Topics include: the development of autogenous, increasingly more intensive, environmentally sound and energy efficient smelting processes; significant improvements in Peirce-Smith converting practice and at the same time the commercialization of alternative continuous converting routes; the consequent expansion and modernization of smelters; the increasing compliance with strict government environmental regulations in most copper producing regions of the world; the realignment of the copper smelting industry throughout the world; and trends in copper smelting R&D. A look at the future closes these reflections on the contribution of the Copper-Cobre conferences to the advancement of copper smelting technology.

Jan 1, 2007

The Bureau of Mines is responsible for a broad spectrum of programs for meeting the diverse and changing mineral resource needs of the Nation. These programs are managed by the Director and two Deputy Directors, who formulate general policy and program direction from the Washington, D.C., headquarters. A senior advisory staff, consisting of the Chief Staff Officer, Chief Scientist, and Chief Mining Engineer, provides advice and consultation to the Director on a wide range of scientific and technical matters and acts on behalf of the Director to maintain liaisons with other government agencies, mineral industries, and professional societies. Bureau program activities are classified into two major functions: (1) Developing new and improved technology that will make the production and processing of minerals more efficient, safer and more healthful for mineral workers and the public, and more compatible with a quality environment.

Jan 1, 1979