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By N. L. Wimmler

"INRODUCTIONSedimentary deposits of titaniferrous magnetite occur at various localities in the eastern foothills of the Teton Ranse in Deer Lodge County, Mont. The Choteau deposit was examined by a Bureau of Mines engineer in August 1942. An exploration project was recommended.Core drilling exploration was begun in June 1945; it was concluded in August 1945, Seventy-six holes were drilled. This report presents the data obtained by the Bureau of Mines exploration.ACKNOWLEDGMENTIn its program of exploration of mineral, deposits, the Bureau of Mines has as its primary objective, the more effective utilization of our mineral resources to the end that they make the greatest possible contri¬bution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, Chief, conducts preliminary examination, performs the actual exploratory work, and prepares the final, report. The. Metallurgical Branch, R. G. Knickerbocker, Chief, analyzes samples and performs beneficiation tests. Both of these branches are under the supervision of Dr. R. S. Dean, Assistant-Director. The field work was supervised by Earshel W. Newman, engineer in charge of the Helena Field Office. D. B. Hoiekvam was the project engineer; he provided most of the data used in the preparation of this report."

Dec 1, 1946

By Jr. Hazen

Relationships that may exist between assays and sample interval lengths when using unequal sample intervals in mine sampling have been investigated as part of the larger research problem of adapting statistical methods to the analysis of weighted average grades. The theoretical relationship between the amount of difference in the weighted and unweighted average grade of ore and the size of the correlation coefficient between assay value and sample interval length was found to be linear. Numerous examples of actual field sample and assay data, which have been obtained by using unequal sample intervals, are documented, and the differences between weighted and unweighted average grades of ore and the correlation coefficients between assays and sample interval lengths have been computed and plotted on graphs. Differences between these actual field data and the expected theoretical linear relationship are examined. It is hypothesized that the use of unequal sample intervals in mine sampling is, in fact, stratified sampling in a statistical context. The sampler establishes stratification by selecting unequal sample intervals on the basis of differences in lithology, changes in rock type, characteristics of mineralization, or differences in metal content. Statistically} methods currently used in mine sampling, involving unequal sample intervals, fail to consider differences in the inherent variances in grade of ore within the various strata established by using unequal sample intervals. Consequently the strata are sampled with different precision. This difference in precision of sampling between strata may account for much of the deviation between the plotted points representing actual field sampling data and the theoretical linear relationship between the amount of the difference between weighted and unweighted average grade of ore and the size of correlation coefficient between assays and sample interval lengths.

Jan 1, 1966

By Michael G. Pojar, John K. Ahlness

"The copper industry has had a long and interesting history associated with leaching, involving vat, dump, heap, and in situ methods. The Bureau of Mines has also had an interest in copper leaching and has researched the techniques of solution recovery, particularly concentrating on in situ methods. In situ mining is a relatively low cost method and has been proven commercially successful by nine operations. It has been most commonly used for final recovery in old workings at the conclusion of conventional mining operations.This report brings together information about 10 commercial in situ operations as well as 14 experimental projects. These 24 sites comprise most of the in situ copper mining activities that have taken place in the United States. Background information, geology, ore preparation, solution application, and recovery and processing are provided for each operation. Production data and tables summarizing the engineering statistics for each operation and an extensive in situ mining bibliography are included. INTRODUCTIONThe purpose of this Bureau of Mines report is to summarize the documented in situ copper leach mining activities that have taken place in the United States. It was prepared to provide a source of engineering and operating data upon which future in situ copper mining activities can be based. Twenty-four different sites are discussed. These are all of the sites that are known to the authors from the extensive in situ copper leach mining bibliography developed at the Bureau's Twin Cities (MN) Research Center (Appendix B).In situ copper leach mining activities fall into the following categories:1. Commercial operations with ore body preparation.2. Commercial operations in old mine workings.3. Experimental programs.Ore body preparation includes such activities as blasting, block caving, and hydraulic fracturing (hydrofracing) specifically to fragment the ore body. Operations in old mine workings include those done in open pits, worked out block caved areas, and backfilled stopes where leaching is done as an afterthought to conventional mining. Experimental programs are small-scale tests of the feasibility of a commercial operation. Some of these programs did not progress to the point where leach solutions were applied to the ore.Each operation (locations shown in figure 1) will be discussed in terms of background information, geology, ore preparation, solution application, recovery and processing, and engineering and production data. Information was collected from published reports, communications with company personnel, and site visits."

Jan 1, 1982

By Joseph E. Matta

The Bureau of Mines conducted a field study to investigate thin suppression of respirable dust by water sprays on a continuous-mining machine. Determining the importance of the top and bottom sprays for two types of spray nozzles was emphasized. Results showed, at a 90-pct confidence level, that (1) at least 70 pct of the dust was generated during the sump cut, even though nearly half of the coal was mined during the downshear operation, (2) the water sprays on the top of the boom had little effect in suppressing respirable dust, and (3) B.D. 5 spray nozzles mounted beneath the boom reduced dust at least 33 pet more than B.D. 5 sprays mounted on top of the boom. A single-cut technique was developed that gave good reproducibility for replicate cuts (coefficient of variation of 20 pct).

Jan 1, 1976

By M. O. Magnuson

This publication describes abandoned-mine fire-control work administered by the Bureau of Mines under cooperative agreements with State and local governments. The work was done by private contractors under the supervision of Bureau engineers. The work is authorized by Public Law 738, approved August 31, 1954, and Public Law 89-4, approved March 9, 1965. Earlier work was authorized by Interior Department Appropriations Acts for fiscal years 1949-55. A total of 70 fires have been controlled under this program in the eastern bituminous region. The nature and extent of the abandoned-mine fire problem in the bituminous region is discussed, and the methods used for controlling these fires are described. The methods that have been used, either singly or in combination, include loading out and cooling the burning material, installing fire barriers, surface sealing, and water and pneumatic flushing.

Jan 1, 1974

By John R. Reigart

The Tri-State district, as its name indicates, is composed of portions of three States, the southeastern corner of Kansas, the northeastern corner of Oklahoma, and an adjacent strip of Missouri east of these portions of Kansas and Oklahoma. An area approximately 40 miles long in a northeasterly-southwesterly direction, and 30 miles wide at right angles thereto, containing minable occurrences of ore at widely scattered locations, comprises the district. However, what has been and is the main productive area, is a strip about 35 miles long and 10 miles wide, which begins at Miami, Okla., as its southern extremity and runs in a northeasterly direction through Commerce, Picher, and Hockerville, Okla., Baxter Springs and Galena, Kans., and Joplin, Webb City-Carterville and Carthage, Mo. Almost the entire present production comes from the area between Commerce and Baxter Springs.

Jan 1, 1932

By John Nagy

A study was made in the Bureau of Mines experimental coal mine of factors affecting gas ignition by a cutoff explosive charge. Experiments showed that, although gas could be ignited under some circumstances, the probability under normal mining conditions would be low. The use of permissible explosives, relatively short-delay intervals in firing adjacent holes, blasting to a 6-inch kerf, and reasonable care in the placement of the holes favor safe blasting and are current practice in mining. The experiments also showed that the weight of the charge is not a primary factor in the ignition of gas by a cutoff charge. The quenching action of a first charge on the igniting action of a second was verified in a supplementary study. Related experiments have shown that gas at the face may be ignited by a single charge of explosive when fired with a light coal burden. Permissible explosives were less hazardous under these conditions than nonpermissible explosives. The frequency of gas ignition in cutoff and single-charge experiments increased as the linear distance between the sheared face and the opposing mine rib increased.

Jan 1, 1960

By Clarence Hall, CHARLES F. MUNROE

Of the common causes of the larger mine accidents, such as falls of roof and coal, gas and dust explosions, mine fires, and the misuse of explosives, all of which are often closely related, each must be studied and fought in a manner peculiar to itself. The last mentioned, the misuse of black powder and other explosives, is sometimes considered the least important of these causes of mine accidents; but its impor- tance is much greater than the statistics indicate, for the reason that the misuse of explosives is the true cause of many of the fatal mine fires, gas or dust explosions, and falls of roof that are credited to other causes. Both the quantity of explosives used and the number of purposes to which they are applied are increasing. They are now made at about 150 plants, in different parts of the United States, and the product of a single year is estimated at nearly 500,000,000 pounds. Nothing in all this material is a safe or "safety" explosive when in the hands of a careless or ignorant person; and this is true whether considered in connection with the shipment or the use of these explosives. In addition to the large losses of life and property resulting from an improper use of explosives in mining, the recent statistics of the railway bureau for the safe transportation of explo- sives have shown more than 400 persons killed or injured and over $3,000,000 worth of property destroyed by explosives in transit by rail. The fact that three years of cooperative effort under the wise supervision of this bureau has reduced these losses to almost nothing encourages the hope that similar cooperative effort may likewise greatly lessen losses of life and property from the use of explosives in mining. The additions to the large death roll of our mines make a recurring appeal to the public for fair treatment of the coal-mining industry, and to the miner and the manager that they join in every possible effort for greater safety. It may never be possible under conditions such as exist to-day to prevent mine accidents entirely. Little can be accomplished in that direction by either the operators or the miners working alone, but experience in all countries shows that

Jan 1, 1911

By Richard D. Mehring

A refined ad improved self-sealing brattice for use in coal mine rescue and recovery operations for directing the flow of air has been developed and tested by Goodyear Aerospace Corporation for the U.S. Bureau of Mines. The brattice is made from a lightweight, low cost material that meets MSHA flammability requirements. The units can be erected using pins, spade or lightweight extensible poles. Tests here conducted to determine leakage rate from minimal to a maximum of 1.5" H20. The ability to handle reverse flows was demonstrated and a non-flammable foam was used as an auxiliary sealing agent.

Jan 1, 1978

By D. Harrington

Before the present century there existed a fairly persistent demand for the establishment of a Federal Department of Mines, but relatively little was done about it until a considerable number of very serious coal-mine disasters in 1906, 1907, 1908, and 1909 created what might almost be termed a national scandal and virtually forces the Federal. Government to take action to try to solve the problem of the cruse and prevention of such disastrous occurrences. Instead of a Department of Mines, the mining people had to accept a bureau, which was created on July l, 1910; and while the Bureau of Mines was given numerous functions, unquestionably the promotion of safety in the mineral industries was and continues to be one of its main "jobs." The Bureau's organic act was approved in 1910 and amended in 1913. Both the original and amended acts indicated that promoting; the health and safety of the mine workers constituted the chief function of the Bureau, and that this was the construction placed on its activities by those put in charge in 1910 is shown very definitely by the fact that as soon as the Bureau came into existence on July 1, 1910, both health end safety activities were started in its Mine Accidents Division. Before the end of the first fiscal year (June 30, 1911) 6 mine safety stations had been established in various parts of the United States, add 6 nine safety cars had been put into the field; by October 1910 first-aid-training work was being done in mining regions. The Bureau eras able to function so promptly in its safety work largely because sections of the Geological Survey, which had been doing some coal-mine safety work since 1907 or 1905, were transferred into the Bureau when it began to operate in July 1910. On October 30, 1911, a national First-Aid Meet was held at Pittsburgh, Pa., at which first aid and mine rescue were demonstrated. During the fiscal year 1910-11, the first year of the Bureau's existence, 509 persons were given certificates indicating completion of the Bureau's training course in first aid.

Jan 1, 1939

By Edmund Shaw

This paper is one of a series being prepared by the United states Bureau of Mines describing mining and milling methods and costs at industrial mineral plants throughout the United states. These papers are designed to disseminate technical information regarding the methods and equipment used. The cost tabulations represent operating expenditures only and not total production costs. It is recognized that publication of total production costs might, in many instances, cause embarrassment to individual producers as well as to the industry as a whole. On the other hand, operating costs are essential to the technical discussion and study of the methods employed. The attention' of the reader? is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations shall ensue. P. J. Weisel, Inc., with office at La Habra and plant at Corona, Calif., is the only local company that produces sand for the Los Angeles glass factories, although silica sand for other purposes is produced in other parts of southern California and the adjacent portions of Nevada. The deposit at Corona consists of coarse sand imbedded in a whitish clay and differs greatly from the other deposits, which are fine-grained sandstone that must be crushed before it can be screened and washed. The preparation of Corona sand has to be thorough and includes grinding in tube mills, repeated washing and rinsing, removal of dust by air separation, and magnetic separation of iron and other minerals. This requires a plant with a complicated flow sheet. The first plant built did not make a. satisfactory glass sand, and many additions and changes were necessary. It is thought that the present flow sheet will remain substantially unchanged until a new plant is built. The design of a new plant would be simpler, but the process would be the same.

Jan 1, 1937

By S. J. Gerdemann

In support of its objective to improve mine safety, the Bureau of Mines has searched for better materials and systems to anchor roof bolts. TIlis report describes a study on the effects of mine waters upon accelerated gypsum, one of the materials under consideration. The accelerated gypsuw dissolved at an appreciable rate relative to an assumed 10-yr life span of a roof bolt. Surface orientation, initial ion concentration of a dissolving solution, and flow rate of the solu-tion had substantial effects on the dissolution rate. Factors such as water-cement ratio, accelerator content, wax capsule additions to the gypsum in cartridge-installed bolts, surface area, temperature, and curing duration had little effect. In an actual roof-bolt environment, dissolution will occur in static solutions to the solubility limit of gypsum (~2 giL) and cease, result-ing in minimal damage; but in flows of unsaturated solution as slow as 1 L per month, a loss of up to 10 pct will occur in 2 yr. Since miners cannot readily measure the flow or ion concentration of static-appearing water at every roof-bolt site, all such water must be assumed to be pure and flowing. It is recommended that gypsum-bonded roof bolts be confined to dry roofs only.

Jan 1, 1983

By L. C. IlsLey, H. H. Clark

As part of its investigations of the causes of mine accidents and of the safest and most efficient methods of handling electricity underground, the Bureau of Mines undertook a study of the ignition of mine gases by the filaments of electric incandescent lamps. This bulletin describes the investigation in detail and gives a complete record of the results obtained.

Jan 1, 1913

By R. C. Annear

This report describes open, sublevel, and shrinkage stoping at the Greenwood mine, operated by Inland Steel-Co. The iron ore mine is in Marquette County, Mich., about 6 miles southwest of Ishpeming (fig. 1). The Greenwood is one of three active underground hard-ore mines on the Marquette range, the others being the Cliffs-Shaft and the Champion mines. The operation reflects an achievement in exploiting small, difficult-to-mine hard-ore bodies lying beneath a 200-foot overburden of glacial drift, which is partly water bearing. This report can indicate only briefly the efforts of personnel in overcoming adverse conditions in mining more than 2 million tons of ore, 80 percent of which was in lump form, for open-hearth production of steel. Significant data presented include descriptions of the principal mining methods employed, sublevel and shrinkage stoping; percent aged mining costs for the entire year 1957, covering both direct mining costs and general expenses; and performance records in units of labor, power, and supplies.

Jan 1, 1960

By A. L. Engel

This investigation was undertaken to assess the feasibility of processing an extensive deposit of iron ore near Palisades, Eureka County, Nev., previously penalized for high phosphorus content. The experiments described indicate a satisfactory accomplishment of objective. Chemical treatment will permit a high-phosphorus iron ore to be used. Leaching with acid solution effectively lowers the phosphorus content with a [gligible] loss of iron. The use of hydrochloric acid is preferred because [ ] does not contaminate the ore and the cost is lower. Minus-1/2-inch ore was satisfactorily leached in 24 hours, minus-1/4-inch ore, in 8 hours, and minus-10-mesh ore, in 3 hours. About 40 pounds of acid per ton of ore was consumed in each instance.

Jan 1, 1959

By C. B. Manula, R. L. Sanford, R. A. Rivell

PART I. FLOW CHARTS

Jan 1, 1974

By Frank E. Williams

This Bureau of Mines report deals with the urbanization of Tucson, Ariz., a southwestern city with an arid environment. Zoning regulations concerning known aggregate sources are described, and information relating to projected needs for the urban area is furnished. History of growth is outlined not only for the local aggregate industry, but also for the entire urban area. Past conditions are pointed out and background material for future conditions is provided.

Jan 1, 1967

By Allen D. Look, Stanley M. Walker, Van Fleet. Leonard A.

"INTRODUCTION The hazards to be encountered in temporarily or permanently abandoned underground mines, quarries, and open pits are numerous, and hardly a year goes by without several reported cases of fatal or serious injuries occurring to unwary people who enter these old mines. Persons visiting mining areas for the first time, tourists, and young people, especially, proceeding in the spirit of adventure common to youth or to the venturesome have suffered many such accidents during exploration trips. The possibility of salvaging salable or usable equipment prompts men and boys to go into old mines, some through ignorance of the attendant hazards, but some jeopardize their lives hopeful of gain (in some cases pitifully small), thinking the hazards are not dangerous and that they can ""get away with it.""Persons fall into unprotected holes, some seek shelter from storms under high banks, and quarries and open pits are often chosen as places for recreation, picnics, swimming, etc; all such uses of these places are likely to be hazardous and to lead to accidents, frequently fatal.These hazards are known to men in the mining profession, and the danger to the public is realized by most of them. A solution to the problem has been sought at many mining meetings, and it is recognized that complete prevention of entry into old mine workings and surface mining areas is the ideal solution, but this, unfortunately, is not always practical; better education of the public, particularly children, should help to reduce the number of such accidents and will be effective in direct proportion to the extent and vividness of such education."

Aug 1, 1948

By Donald P. Schlick

The Federal Coal Mine Health and Safety Act of 1969 requires each mine operator to implement the respirable dust sampling program established by the Secretary of the Interior and the Secretary of Health, Education, and Welfare. This program requires frequent sampling of "high-risk" face workers and periodic sampling of other underground workers. Dust samples are collected by the coal mine operator and weighed at the Bureau's Pittsburgh Field Health Group, and the results are processed by the Bureau's Automatic Data Processing Section located in Denver, Colo. This paper presents the system employed by the Bureau to weigh the dust samples and to process and store the data.

Jan 1, 1971

By Kathleen M. Kowalski

This research explores the emergence of leadership in a crisis situation. The study by the U.S. Bureau of Mines focuses on three underground mine fires and the resulting evacuations. The subjects for this study are 48 coal miners, who evacuated the mines as part of eight escape groups, The subjects described their escape during an open-ended interview. Data were coded according to: (a) evidence of leadership behavior, (b) evidence of lack of leadership behavior, and (c) characteristics of the individual in each group who led the subjects out of the mine. During analyses, attributes of the leaders, who facilitated the escapes, were noted and compared as were instances of lack of leadership. The structure of the group leadership before the crisis was compared with the reality of the leadership during the crisis. Some groups experienced an apparent breakdown of leadership during their escape, while others witnessed the emergence of leadership. Consensus characteristics of the leaders, who emerged during these crises, are discussed and generalizations drawn. Research into leadership during emergency escapes is needed to provide information for training in prevention, escape, and rescue. The authors suggest questions for further investigation and topics for further inquiry into the area of leadership evolvement during crisis.

Jan 1, 1994