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By F. J. Bailey

"In the fall of 1919, the U.S. Bureau of Mines began an inquiry as to the possibility of utilizing airplanes in conjunction with its rescue work, for quickly transporting engineers and oxygen rescue-apparatus to mine disasters.It was realised that this proposed use of airplanes has serious limitations, and if it were feasible, that the Bureau would have to rely on the cooperation of the established aviation fields of the U. S. Air Service for furnishing airplane service. Therefore Van. H. Manning, Director of the Bureau of Mines, under date of October 28, 1919, wrote the Director of Air Service outlining the rescue and first aid organization of the Bureau, the location of headquarters of district engineers, the distribution of safety cars and stations, and other essential details, and asking whether the Air Service could cooperate with the Bureau in the event of serious mine disasters. Major-General Charles T. Menoher, Director of Air Service, responded that the Air Service would be glad to cooperate insofar as possible, and designated those Air Service stations nearest the district engineers' headquarters, which might be best able to assist.The Bureau of Mines has ten mine rescue cars and eight mine safety stations distributed throughout the mining regions of the United States. The cars are each equipped with sets of oxygen mine-rescue breathing-apparatus and first-aid supplies. The car personnel consists of a mining engineer, surgeon, foreman, first-aid miner, clerk and cook. A foreman miner is in charge of each station and at five of the eight stations are mine safety trucks. The work of the cars and stations is two-fold; (1) Assisting in rescue and recovery work at mine disasters, and (2) training miners in mine rescue and first-aid methods, and in investigations looking to prevention of mine accidents. The country is divided into nine safety districts, with nine district engineers in charge."

Apr 1, 1920

By J. J. Geraghty

U.S. Bureau of Mines researchers investigated the development of an innovative transport system for underground coal mining. A one-half commercial-scale bench model was constructed. Novel magnetic levitation (mag-lev) technology was developed. Frictionless and contact-free transport of a prototype materials container and payload has been demonstrated.

Jan 1, 2010

Measure tattling in cemented backfill when installation of bore-hole extensometers is not feasible. Problem To evaluate the amount of load that backfill carries during pillar recovery, information about how much the backfill settles after placement is often required. However, the composition of some backfills makes them difficult to drill and the installation of borehole extensometers almost impossible. Approach Bureau researchers have developed a vertical fill extensometer that can be cast in place as a stope is being filled. It consists of a baseplate, sections of steel pipe enclosed in loosely coupled polyvinyl chloride (PVC) pipe, and a top anchor assembly that contains a displacement transducer (fig. 1).

Jan 1, 1990

Objective Develop field measurement and computer modeling methods to predict the potential for hang-ups and structural failures in underground mine ore paws. Background Analysis of Mine Safety and Health Administration (MSHA) accident statistics has identified ore pass hazards as a significant safety problem in underground metal mines in the United Stales. Recent ore pass failures have underlined the lack or ore pass design methods ant1 standards available to both MSHA and mine engineers. Injury and fatality data for the 20-ycar period between 1975 and 1095 show that nearly 75% of the injuries were directly or indirectly related to pulling or freeing ore pass chutes, the use of hand tools, falls or broken rock, and structural failures or chutes or gates and ore pass walls.

Feb 1, 1998

By M. J. Ankeny

The expression "firing open, unconfined shots," as used in this circular, means the firing of explosive charges not confined in boreholes. Examples are the so-called mudcap shots, adobe or dobe shots, or bulldozing shots consisting of explosive charges placed on, under, or between rocks for the purpose of breaking them. The practice of firing open, unconfined shots is not uncommon in coal mines, despite the fact that numerous mine explosions and dust ignitions have resulted from this practice. The usual method of preparing such shots is to place the explosive with its detonator on top of a piece of rock or coal and cover it with clay, loam, sand, or road dust; frequently no covering of any kind is used. In some mines, an open charge of explosive is placed on timbers to dislodge them or in crevices in the roof to break down loose rock that cannot be dislodged with a bar or pick. The explosive charges may be made and fired singly, although sometimes several charges are placed on one large piece of rock with a detonator in each charge, and all charges are fired simultaneously. Although it is general practice to use permissible shot-firing devices, which will not ignite gas or dust to fire these charges, electric power from the regular mine circuits is sometimes used. When the shot is fired, any coal dust that may be present is thrown into suspension by the blast and may be ignited by the intense hot flame of the explosive or by an arc or spark at the leg wires or the end of the firing leads if power from the regular mine circuit is used to fire the shot. Even if there is not enough coal dust present to form a dust cloud, open, unconfined shots can readily ignite methane.

Jan 1, 1952

By E. Morrice

Gadolinium, dysprosium, and yttrium are difficult to electrowin as high-purity liquid metals because of their high melting points (>1,300° C). Samarium metal is difficult to prepare directly by electrolysis because the metal reacts with the electrolyte. In this Bureau of Mines study, the rare-earth metal was electrodeposited on a solid manganese, chromium, or iron cathode to form a low-melting alloy. The alloy was then vacuum distilled to separate the rare-earth metal from the ferrous metal. A typical samarium metal product, obtained as the distillate from vacuum distillation of a samarium-iron alloy, contained 150 ppm oxygen, 80 ppm carbon, and 50 ppm iron as impurities, Gadolinium metal, obtained as a residue from the distillation of a gadolinium-chromium alloy, contained 300 ppm oxygen, 200 ppm carbon, and 100 ppm chromium.

Jan 1, 1969

By R. O. Pynnonen

Tunnel-driving is recognized as a hazardous occupation; adequate support of roof and sides for preventing accidents from falling material is usually one of the most important safety problems. Where extraordinary conditions of sand and water are found, this problem becomes even more difficult. Tunneling at the Tioga No.2 mine was stopped when a 22-foot bed of water-saturated, fine gray sand was encountered. The tunnel, designed to house an ore-conveyor belt, was being driven from both ends. Driving was extremely difficult at both the upper and lower faces when the sand horizon was reached. A distance of 178 feet remained between the faces. Heavy pressures deformed the steel-supporting rings at the upper face, and there was an inrush of mud and sand at the lower face.

Jan 1, 1958

By Harold M. Smith

The production of oil during the early development of new oil fields is usually accompanied by large quantities of natural gas. Since In most fields gas under pressure is the main source of the energy causing the oil to move throug the sands into the wells and thence to the surface, this coincident production of natural gas will contime as long as present day producing methods are used. Generally the use of this gas is restricted, and markets are not readily available Consequently, a large portion of the gas produced at such times is often wasted by being blown into the air.

Dec 1, 1930

By L. H. Wullstein

Bureau of Mines research on methods for reclaiming land disturbed by the minerals sector of the economy has produced a specific procedure for effectively germinating seed of Indian ricegrass, a drought-tolerant plant valuable for reclaiming arid and semiarid sites. This report describes the procedure which consists of acid-treating the seed followed by temperature and light cycling treatments. Use of the procedure resulted in an average germination rate of 29 percent, ranging from 18 to 56 percent. Seed subjected to long cold treatment but with acid treatment yielded an average germination rate of 9.2 percent, ranging from 6.6 to 14.7 percent. Untreated seeds (controls) gave germination rates less than 0.1 percent.

Jan 1, 1979

By Robert P. Vinson, Fred N. Kissell, Edward D. Thimons

Because of the high number of accidental methane gas ignitions in metal and nonmetal mines, the Bureau of Mines searched for a simple guideline that would allow mine personnel to evaluate the methane hazard in a given mine. Air samples were collected by the Bureau in 53 metal and nonmetal mines and analyzed for trace evidence of methane gas. Samples were collected in the returns and at the working faces. Those mines classified as gassy by the Mine Safety and Health Administration had a significantly higher average methane concentration than those classified as nongassy. Of the 9 gassy mines sampled, 7 had methane concentrations above 100 ppm, whereas only 1 of the 44 nongassy mines had a concentration above 100 ppm. The 100-ppm concentration may be used as a simple and convenient guideline for forecasting the methane hazard in a mine, whether or not the mine is classified as gassy. There was no consistent correlation between commodity mined and methane concentration, nor was there a correlation between mine depth and methane concentration. Neither of these factors can be considered a guideline for predicting methane hazards.

Jan 1, 1979

By Owen W. Terry

During the summer of 1943 the Bureau of Mines conducted an investigation and program of churn drilling on the McIlhon and adjoining Pearson land in the Mineral Point district of Iowa County, Wis. Sixteen holes, aggregating 1,570 feet .of bore, were completed. The work was undertaken as part of a general investigation of the zinc-and lead-producing area of southwestern Wisconsin at a time when great effort was being made to increase the production of Metals important to the war program. The Bureau's drilling program supplemented a previous drilling pro-gram conducted by the Vinegar Hill Zinc Co., and demonstrated the presence of a strongly mineralized zone at relatively shallow depths.

Jan 1, 1948

By Eric E. Cather

A mineral investigation by the U.S. Bureau of Mines revealed no mines or prospects and no past or present mining claims in the Agua Tibia Wilderness Study Area (WSA). The area is underlain mainly by weakly foliated gabbro similar to rock that has hosted gem- and lithium-bearing pegmatites in the Pala district about 6 mi to the south. However, no gem- or lithium-bearing pegmatites have been discovered in the WSA. Nearby quarries in the gabbro have yielded rock for facing and dimension stone. No sand, gravel, or energy (oil, gas, coal, or geothermal) resources were identified.

Jan 1, 1984

By R. L. Montgomery

The heats of solution of erbium chloride in water and in hydrochloric acid and of erbium oxide in hydrochloric acid were determined. The results reveal a discrepancy of 10.5 kcal. per gram-atom between the heats of combustion and solution of erbium reported in the literature, the heat of combustion being more negative. The heat of combustion of erbium t4)4 and its heat of solution in hydrochloric acid (1, 18) have been reported in the literature. The heat of solution of erbium chloride was determined in two studies (2, 19). The present work was undertaken to check the reported heats of solution of erbium chloride and to determine the heat of solution of erbium oxide in hydrochloric acid. The latter quantity permits the heats of combustion and solution of erbium to be compared for mutual consistency. It was also desired to determine the degree of similarity between the thermochemistry of yttrium and erbium.

Jan 1, 1961

Reduce dust exposure of longwall shearer operators by keeping them upwind of the primary cutting drum. Approach Use a different coal cutting sequence by cutting from headgate-to-tailgate, making the cleanup pass from tail-gate-to-headgate. How It Works The cutting action of the shearer drum is usually the primary source of respirable dust at longwall shearer faces. Dust exposure of the shearer operator is deter-mined by his position relative to the lead drum, which is normally in the raised position taking a full sump. On long-wall faces where the cut pass is taken from tail-to-head, against the primary airflow, the shearer operators must remain at their controls, on the return-air-side of the primary dust source, to maintain proper control. A simple method to lower shearer operators' dust exposures is to extract the primary coal from head-to-tail, thus positioning the operators up-wind of the lead cutting drum. The bottom coal is then cut, and the floor cleaned by the trailing drum during the tail-to-head cleanup pass. This sequence places the primary dust source, the cutting action of the shearer drums, on the return-air side of both shearer operators, except when cutting out at the longwall headgate.

Jan 1, 1984

By John Nagy

This circular has been prepared for the guidance of safety engineers, shot firers, and coal-mine inspectors concerning multiple blasting with short-delay (millisecond-delay) detonators. These special precautions are suggested in addition to those normally followed in blasting, as outlined in the Federal Mine Safety Codes 5 6/ and in Miners' Circular 58.7/ INTRODUCTION The use of short-delay blasting has been proposed for promoting safety and increasing the rate of production in coal mining. Ideally, short-delay blasting, as compared with equivalent single-shot blasting, reduces exposure of the shot firer to dust, fumes, and weakened roof; as compared with equivalent simultaneous blasting, it reduces roof disturbance.

Jan 1, 1959

By John A. Davis, John Gross

This paper is one of a series giving the results of metallurgical tests conducted by: the Alaska station of the Federal Bureau of Iſines, on the recovery of gold from the black sands of placer clean-ups. The data given in this report were obtained from tests on a lot of black sand from a property located on St. Patrick Creek, Fairbanks mining district, Territory of Alaska. This property comprises the Sagan Fraction and adjoining bench claims, and is being operated by J. A. Lillie. The sand ad already been treated at the mine by amalgamation. A sample taken by Mr. Lillie and assayed at the station showed that the gold still remain ing amounted to ll cents per pound. As this gold content was sufficiently high to justify further treatment of the same, 770 pounds were shipped to the station for testing. The reader will note that the gold content is given in cents per pouni, rather than per ton. This is in conformity with practice in the district in valuing black sands, as the quantity obtained at any one time is small, much less than one ton. . The sand consisted principally of schist and quartz, with very little ilmenite and garnet; and no magnetite or sulphides. Most of the gold present as contaminated with quartz, as the free particles of gold had been removed by amalgamation at the mine.

Sep 1, 1920

By Raymond B. Ladoo

The Bureau of Mines frequently receives requests for information on the mining , preparation and marketing of epsomite or Epsom salt , and in order to answer such inquiries the following information has been compiled . While it is probable that few people have considered epsonate as a mineral product , it will be noted that it should be so regarded and its production forms an important industry .

Mar 1, 1922

To develop a quick, safe, and effective method that allows workers at mineral processing operations to clean their dust-soiled clothing periodically throughout the workday. Background Reducing workers' respirable dust exposure to silica and other harmful dusts and contaminants is an ongoing goal in the U.S. mining industry. One area of known worker exposure is from contaminated work clothes. A U.S. Bureau of Mines report documented a number of cases where a tenfold increase in a worker's dust exposure was measured from contaminated work clothes. In these cases, the dust emitted from clothing caused the worker's dust exposure to exceed the permissible exposure limit in less than 2 hours. The most effective way to eliminate this dust source is to have workers clean or change their work clothes. There are two federal regulations that impact the clothes-cleaning process. The first states that at no time shall compressed air be directed toward a person, but that when compressed air is used, then all necessary precautions shall be taken to protect persons from injury. The second regulation states that compressed air should only be used for cleaning purposes when it is less than 30 psi and used along with personal protective equipment. For the mining industry, by default, the only approved method to perform clothes cleaning is to have workers vacuum their clothes using a HEPA filter system. This is very difficult and time-consuming and, in most instances, not very effective. Most workers would prefer to use a single compressed air hose to blow dust from their work clothes. However, not only is this method prohibited by law, it usually creates a significant dust cloud in the work environment and contaminates coworkers.

May 1, 2005

To expediate the transfer of technology from Bureau laboratories into new products and processes that enhance the economic competitiveness of the U.S. mining and minerals industry in world markets. Background The U.S. Bureau of Mines and various members of the industry are concerned about the current technology challenge to the minerals industry in the United States. They arc working together to delineate ways of enhancing the mineral industry's technology base. More emphasis is being placed on collaboration between the government, academia, and industry to formulate the innovative revolutions needed to maintain our technology edge. Through these partnerships, real issues and problems can be identified, the industry's needs as customers can be defined, and research and development activities can be tailored to meet these needs. Now is an especially exciting time in research because some special opportunities exist to encourage private industry to capitalize on Federal laboratory research and development. These opportunities arc called CRADA's. What Is A CRADA? The Congress recently enacted a mechanism that enhances collaboration between industry and government through the Technology Transfer Act of 1986. A key lea lure of this Act is a provision through which Cooperative Research and Development Agreements or CRADA's can be developed to encourage industry and government to work together and stretch their research budgets. By entering into a CRADA, a private, non-Federal company can cost-effectively perform research by sharing the costs of this research with the Federal Government. The agree¬ment involves no transfer of funds from the Government. The Government agrees to provide personnel, services, facilities, equipment or other resources (but nut funds) and the non-Federal party agrees to provide funds, personnel, services, facilities, equipment, or other resources needed to conduct a specific research or development effort.

Jan 1, 1992

In the interest of safety ii: coal mining, the Bureau of Mines recommends: That all active underground coal mines, whether working or idle, have one or more fans in continuous operation. The capacity and installation shall be such that the entire mine workings are adequately ventilated at all times. Main fairs shall be located on the surface in fireproof housing offset from the line of any mine opening. The housing shall be provided with ample pressure-relief doors or other devices easily opened by the force of an explosion. The installation shall permit prompt reversal of air flow. For mines that liberate gas, the fan shall have at least two independent sources of rower immediately applicable. Ventilation of underground workings in coal mines is needed whether or not explosive gas is present. Natural ventilation is unreliable and often uncontrollable. Main fans should be on the surface; if they are in the mine, fire or explosion may make access difficult or dangerous and render the installation inoperative.

Jan 1, 1939