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By Larry R. Wilson

The development effort described herein was directed toward the design and development of a flexible communication system to provide two-way section communications between any telephone on an MCM-101 telephone FDM exchange and a miner provided with a uhf walkie-talkie transceiver. The system also provides normal communication between miners within a working section through the uhf coupler interface repeater.

Jan 1, 1976

By William W. Adams

The stone-quarrying industry of the United States, including such related operations as rock crushing, rock dressing, and the manufacture of cement and lime, reported a larger volume of employment in 1934 than in 1933. Reports from the operating companies to the United States Bureau of Mines showed an increase in the number of men employed, number of man-days of employment, and total number of man-hours of labor performed during the year. Moreover, the average worker had a longer period of employment during 1934, the gain amounting to 11 percent over 1933. The increase in employment was accompanied by no increase in accidents for the industry as a whole; in fact, the accident rate for 1934 was a fraction lower than the rate for 1933. In some branches of the industry the frequency of accidents increased, but these increases were more than offset by reductions in rates for other branches. Reports for 1934 were received from 1,403 active plants. The working force averaged 64,331 men for 204 days per man, and the total period of employment for all of the men was 95,258,880 man-hours. Each employee averaged 1,481 hours of work during the year. The total number of hours of labor represented a gain of more than 8 percent, and the average working time per employee showed a gain of 62 hours per man.

Jan 1, 1936

By F. E. Joyce

The Bureau of Mines studied copper-nickel minerals (mainly sulfides) of the Duluth Gabbro Complex in north-eastern Minnesota to determine their response to selective high-temperature sulfatization techniques. The gabbro, containing 0.44 percent copper and 0.13 percent nickel, was ground to minus 325 mesh and sulfatized in a heated, rotating, stainless steel bench-scale retort. Tests demonstrated that over 95 percent of the copper and 80 percent of the nickel can be converted to water-soluble sulfates, depending upon the roasting conditions employed. Yield equations were developed using regression analysis for predicting the extraction of copper and nickel between the temperature limits of 520° to 670° C, the roasting time limits of 3 to 7 hours, and S02 limits of 10 to 40 percent in S02-air mixtures.

Jan 1, 1971

By E. J. Lintner

This paper is one of a series being prepared by the United States Bureau of Mines describing clay mining, crushing and grinding methods, and costs at various clay-mining operations throughout the United States. These papers are designed to disseminate technical information regarding methods used. The cost tabulations represent local operating expenditures only and not total production costs. Although the publication of total production costs might not be advisable in some instances, yet a knowledge of operating costs is essential to the technical discussion and study of the methods employed. The attention of the reader is specifically called to-this distinction between total and operating costs in order that no misunderstanding of the cost tabulations shall ensue. The following report deals specifically with the methods employed by the Dennison Sewer Pipe Co., Dennison, Tuscarawas County, Ohio.

Jan 1, 1936

By S. H. Ash

The United States Bureau of Mines has published relatively little on the flooding and unwatering of coal and metal mines. Bulletin 229, Fifty-Nine Coal-Mine Fires, published in 1927, contains several instances of the flooding of mines or sections thereof to extinguish fires but does not describe their unwatering. Report of Investigations 2649, Explosion Hazards Incidental to Unwatering Coal Mines, published in 1924, warned against the possibility of gas accumulations in flooded mines and indicated the precautions to be taken. Report of Investigations 2255, An Unusual Hazard in Reopening Long-Flooded Timbered Metal Mines, published in 1921, told of methane being pocketed and the danger thereof. The flooding of mines originates in many ways. At some mines flooding followed reopening after what was thought to be permanent abandonment; also, explosions have caused some mines to be flooded. Extinguishing fires, accidental encountering of underground streams or flooded old workings, and caves of strata admitting water from underground workings, water-bearing strata, or surface accumulations have also flooded all or parts of mines. Unfortunately, un watering often necessitates much study and causes apprehension largely because experiences in similar situations are not generally known, as few descriptions of successful or unsuccessful methods are available. The job has sometimes been contracted for outside the local management involved and has become a matter of record for the contractor only. As the cost-plus contract system often employed in the past is now known to be expensive, careful managements elect to handle the problem themselves, in line with the general policy of cutting expense where possible. This report describes specific in-stances of successful unwatering by operators.

Jan 1, 1933

By H. A. Schrecengost, H. R. Gil, Alfred Clarkson, E. H. McCleary

Much has been written and many discussions have been held concerning the prevention of accidents in coal mines , and considerable progress has been made in eliminating hazards to the health and safety of underground workmen . Although much progress has been made in the reduction of injury rates in the Pennsylvania anthracite field , the injury rates for the anthracite mines of Pennsylvania are generally higher than the average for coal mines in the United States as a whole , because the mining conditions , including the safety problems , in the Pennsylvania anthracite fields are more complex than in other coal fields of the United States . Several factors contribute to this extremely difficult problem , among which are : Multiple - vein mining , steeply pitching measures , folds or faults , hard smooth floors underneath the veins , and the remining or reclaiming of pillars in severely crushed , broken ground . In the early days of the Pennsylvania anthracite industry , only the more productive veins were mined , and this resulted in bypassing those veins that were relatively thin and those containing considerable proportions of impurities . However , the development of modern coal - preparation equipment , improved marketing conditions , and the adoption of mechanical equipment , such as the various types of conveyors and scraper loaders , have made possible the recovery of the thinner and poorer veins . Furthermore , in the early days , little or no attempt was made to recover the coal pillars , usually owing to the great amount of virgin coal available . Consequently , much of the anthracite produced within the last few years has been recovered by second and third mining and frequently by fourth mining - in areas where operations had been suspended for many years . In such areas , the coal veins and intervening strata are usually crushed as the result of gradual subsidence , which intensifies the hazards incidental to roof control , haulage , ventilation , and mine gases . Moreover , the use of coal - cutting equipment is not practicable in most anthracite mines because of. the inclination of the veins and because , in crushed -ground areas , the faces must be advanced slowly and for short distances at a time to permit the erection of timber sets and the placing of forepoles to support the roof and sides . Thus , the slow process of mining brought about by these conditions has resulted in the production of only 0.424 ton of anthracite for each man- hour worked , as compared with 0.753 ton? for each man - hour worked at other coal mines in the United States . A summary contained in Bulletin 462,8/ a publication of the Federal Bureau of Mines , reveals that the rate of fatal injuries in the Pennsylvania anthracite industry was improved from 13.47 deaths per million tons produced in 1870 to 3.88 deaths per million tons mined in 1942. During the period March 16 , 1942 to January 1 , 1947 , the fatality rate was reduced from 3.88 to 2.87 deaths for each million tons mined . On the million man-hour basis , the rate of fatal injuries was reduced from 1.643 to 1.130 and the nonfatalinjury rate was lowered from 119.01 to 83.12 during the same period . The improvements made in both the fatal- and nonfatal - injury rates have required the cooperation of the workmen , the mining companies , and the State and Federal inspection departments . Many individual mines and companies have achieved commendable safety records which contributed greatly to the over - all average for the industry , particularly during the 1942-47 period . One of the most outstanding of these is the Continental mine of the Continental -Archbald Coal Co. , a member of the Moffat Co. Interests .

Jun 1, 1948

By Oren C. Baptist

[Several new oilfields have been developed in northwestern Wyoming during the past 10 years, production is obtained from discontinuous, permeable sands enclosed within impermeable shales. The energy to drive the oil to producing wells in supplied by gas in solution in the oil. Most of the wells had high-initial potentials, but rates of oil production have steadily declined, indicating a dissipation of the driving energy and the possibility that large volumes of oil will remain unrecovered in the reservoirs. The studies reported in this paper were undertaken to develop laboratory data of the type most likely to be needed by persons studying the susceptibility of the Newcastle sand reservoir to secondary-recovery methods.]

Jan 1, 1957

By D. J. Parker

This report is based on data collected in and about the Liberty mine of the Liberty Fuel Co. by D. J. Parker and W. W. Kessler on December 13 and 14, 1933. An important phase of an examination to determine the general condition of a mine with respect to safety is the collection of dust samples from rock- dusted areas. Definite conclusions, based on intelligent interpretation of the analyses of such samples, can be reached only when the general condition of the mine is known. A similar examination and report were made on this property in January 1930 by D. J. Parker and R. I. C. Manning. Since that time much has been done by the management to improve safety conditions in this mine. The changes made will be noted in the course of this report. The mine is in Spring Canyon at Latuda, Carbon County, Utah, and is served by a branch line of the Denver & Rio Grande Western Railroad about 7 miles long and connecting to the main line near Helper, Utah. The writer desires to express his sincere appreciation for the many courtesies and helpful cooperation extended by Superintendent George Schultz and Mine Foreman F. W. Koelling.

Nov 1, 1934

By Lon A. Williams

This report, authorized under Contract Number H0220065, Amendment Number Six, documents the results of an investigation of lighting system modifications and designs for working place illumination in high and low coal entries of underground coal mines. The portable and machine mounted system designs, both modified and prototype, represent a continuation of work performed under Contract Number H0111403, Amendment Number One. See the Final Technical Report dated May 26, 1972 for detailed information concerning this prior Contract. All modified and prototype systems met the performance requirements of Bureau of Mines Specification 2G, as proved by test. In addition, the systems met the requirement for illumination, as specified in the Contract and in the proposed standards which were generated in response to Public Law 91-173.

Jan 1, 1976

By J. Douglas Causey

In 1986, at the request of the Bureau of Land Management, the U.S. Bureau of Mines studied the 7,940-acre Southern Otay Mountain Wilderness Study Area (CA-060-029), and the 5,750-acre Western Otay Mountain Wilderness Study Area (CA-060-028) in order to evaluate their mineral resources. The wilderness study areas are located in San Diego County, CA, about 20 miles southeast of San Diego. No mineral resources were identified in the Southern or Western Otay Mountain Wilderness Study Areas, based on literature, field observations, and sample results. The wilderness study areas are underlain by a complex blend of Late Jurassic, moderately metamorphosed sedimentary and volcanic rocks. Evidence of mineralization is not obvious.

Jan 1, 1987

By James H. Rowland

The Mine Improvement and New Emergency Response Act of 2006 (MINER ACT) established a Technical Study Panel (The Panel) to provide recommendations on the utilization of belt air and new technology that may be available for increasing the fire resistance properties of conveyor belt used in underground coal mines. The Panel Report recommended use of the Belt Evaluation Laboratory Test (BELT) as the method for testing and approval of flame resistant conveyor belts used in underground coal mines. The research conducted to establish the correlation of the BELT with large-scale belt fire flammability tests was done using 36- to 42-in wide conveyor belt. Due to today?s coal haulage capacity, the mining industry is using 72-in and wider conveyor belts. The National Institute for Occupational Safety and Health (NIOSH) conducted a study to determine if the BELT will also qualify wider belts as fire resistant for use in underground coal mines. This paper describes the results of recent experiments comparing results from using the BELT and the large-scale tests for six different belts.

Jan 1, 2010

By J. B. Gayle

Coke-pushing difficulties have been the subject of much controversy but relatively little scientific investigation. Nevertheless, continuing pushing difficulties can greatly decrease the life of a coke oven and should therefore be considered in the selection of the blend and operating conditions used for coke production. The present Federal Bureau of Mines investigation was undertaken to correlate results of previous investigators and to supplement these results to the limited extent practical by us of an experimental slot-type oven. To this end, pushing pressures have been determined routinely for Tuscaloosa oven tests conducted during the past 10 years. Nevertheless, the accumulated information remains incomplete in many respects, and in view of the recognized inadequacies of the data, publication is now undertaken only because of the scarcity of published information on this important problem and the discontinuation of carbonization studies with this oven.

Jan 1, 1961

By Frank J. Wiebelt

As a result of the examination of many copper-zinc properties in the West Belt area of California, nine were chosen for exploration projects by the Bureau of Mines. This was part of the Bureau's wartime mineral-development program aimed at maintaining production of essential metals and increasing ore reserves. The properties explored were the El Dorado, El Dorado County; Copper Hill, Newton, and Gray House, Amador County; Constellation, North Keystone, and Collier, Calaveras County; and American Eagle and Akoz, Mariposa County. In addition to surface sampling and mapping, 41 holes, aggregating 18,134 linear feet, were diamond-drilled. Detailed results of the work done on all properties except the El Dorado and Akoz are given in this report. The El Dorado and Akoz were discussed in Reports of Investigations 3896 and 4144, respectively. Figure 1 is an index map showing the location of the mines covered in this publication.

Jan 1, 1951

By H. C. Miller

The removal of the mud sheaths that are deposited against the faces of productive oil sands during rotary drilling is one of the important problems confronting operators, especially in semidepleted fields where formation pressures are low. Unless the mud sheaths behind the perforated oil strings and liners are removed and the sands exposed, oil cannot enter the wells. Consequently much oil that otherwise might be produced from low-pressure sands is trapped and never recovered. Various types of perforation washers, down swabs, and agitators are used at present for breaking down the mud sheaths and removing the disintegrated clay particles from wells after the perforated Wipes have been inserted. Mechanical methods for removing mud sheaths are :quite satisfactory, but prompted by the request of certain .operators in the California oil fields Bureau of Mines engineers have conducted a series of laboratory tests with the view of developing a chemical method for removing mud sheaths in oil wells that will be applicable to field conditions. This report describes the laboratory work and deals generally with a chemical method for removing the mud sheath, cake, or plaster deposited against the face of oil sands in drilling wells end in wells that, on being shut in temporarily during periods of overproduction of oil, are conditioned for the shutdown .period by filling the well opposite the producing formations with mud fluid. The method described in this report was devised in the San Francisco laboratory of the Bureau of Mines and, as far as the writers have been able to determine, differs from any chemical method ever used in actual wells. The method proposes to add a small amount of calcium carbonate (preferably pulverized limestone) to the mud fluids before they are introduced into the wells so that the resultant mud sheaths will be susceptible to disintegration by acid solutions when it is desired to expose the faces of the oil sands in the wells.

Jan 1, 1934

By Raymond B. Ladoo

Talc mining ·in the state of New York was first started about 1876, but important production did not start until 1880, when about 4,000 tons were shipped, In 1883 the production was about 6,000 tons valued at $75,000, or an average of $12.50 per ton, From this date the production gradually inc~eased to a peak of 93,236 tons in 1916, valued at $961,510 or about $10,30 per ton, In 1918 the production declined to 71,167 tons valued at $902,100, or about $12,70 per ton. For ma.ey years New York ,-Jas the largest producer in the United states, but in 1917 and 1918 its output was surpassed by Vennont in tonnage thou[;h not in value. In June, 1920, there were three companies producing talc in the Gouverneur district, st. La,1Tence Co'Ul'lty, and one near Natural Bridge.

Oct 1, 1920

By Dennis R. Dolinar

Physical property tests were conducted on drill core from three exploratory holes on the Naval Oil Shale Reserve near Anvil Points, Colo. Data and regression analysis curves are presented. Data obtained above the Mahogany zone were used to estimate the potential zone of surface effects from under-ground mining. Single specimen testing was primarily used to obtain Mohr's envelope and subsequent rock properties. The technique is shown to provide satisfactory results for this rock type with a significant reduction of core preparation and testing time.

Jan 1, 1981

By J. C. Hartley

The most important single operation in mining is the ventilation of underground areas in a manner conducive to the health and safety of employees. Adequate volumes of pure air must be supplied at the working faces, along the haulageways, and wherever men work, so as to dilute and carry away the methane liberated from the coal and adjoining strata, noxious gases evolved by the use of explosives, and the carbon dioxide exhaled by men and formed by oxidation of carbonaceous material, as well as any other gases, and also dusts which may be found in mine workings. A sufficient quantity of air must also sweep abandoned or worked-out areas of the mine to prevent the accumulation of gases, where sealing methods are not utilized to isolate old workings. Air, in a quantity adequate to meet the needs of the particular mine to which it is applied, is necessary, and supplying it can be made very expensive through failure to observe good practices in its direction and apportionment." Leaky stoppings, doors, and overcasts rob the working faces of air and add to the ventilating cost by burdening the fans with fugitive air,

Jan 1, 1944

By A. Wahab Khair

"This paper presents an analysis of fracture mechanisms in coal subjected to bi-axial state of stresses, indentation of laterally confined coal specimen. Coal specimens were loaded to failure by the straight wedge indenters at various lateral confinement pressures. Strain distribution and acoustic emission characteristics of coal specimens under stress were recorded. The influence lines of vertical forces acting on the horizontal straight boundary of the coal specimen for each type of wedge indenter have been established using holographic interferometry technique. The effects of wedge indenter angle, confinement pressure, and coal anisotropy on fracture types, failure modes, and post-failure conditions were studied. The results indicated that combined application of holographic interferometry and acoustic emission monitoring techniques is not only suitable ·for studying deformability of heterogeneous and microscopically discontinuous material under stress but it also enhances the mode of fracture during the post failure stage. INTRODUCTIONOne of the relevant processes in the coal cutting technology is the application of indentation theories. Since most cutting tools in the coal industry are wedge shaped most of the indentation research is found for a wedge shaped tool.A wide range of behavior is found in different rocks subjected to the wedge penetration. A rock which is elastic brittle at standard pressure might become elastic plastic at high confining pressure (Gnirk and Cheatham, 1963). It was also observed that some rocks will merely be crushed and indented by a wedge whereas others will crack and form chips, furthermore the existence or non-existence of chips depends mostly on the geometry of the indenter, type of rock and the depth of penetration (Evans and Murrel, 1958). However, coal cutting technology is mostly explained by models which use rigid wedge to penetrate into a brittle material in which both crushing and chipping will occur (Evans and Murrel, 1958, 1962)."

Jan 1, 1988

By W. W. Adams

"The National Safety Competition of 1930, the seventh annual contest conducted by the United States Bureau of Mines to promote safety in the mines and quarries of the United States, has been concluded, and the five winners of the bronze trophies, The Sentinels of Safety,' which are provided by the Explosives Engineer magazine and awarded annually for the most excellent safety records, have been determined by the committee of award. One trophy was awarded to an anthracite mine in Pennsylvania, one to a bituminous coal mine in the same State, one to an iron-ore mine in Michigan one to a gypsum mine in Ohio, and one to an iron-ore opencut mine in Michigan.These trophies were awarded to the companies for having the smallest loss of time from accidents in proportion to the total number of man-hours worked by all employees at their mine or quarry. Honorable mention was awarded to each mine or quarry that ranked second, third, fourth, or fifth in its own ground and to all plants that were operated without a lost-time accident during the contest year. Eighty-four out of 337 plants that competed for the trophies were operated without an accident that disabled an employee beyond the day on which the accident occurred.Under the contest rules, all mines and quarries were divided into five groups, four of the groups representing different classes of underground mining operations (anthracite, bituminous coal, metallic ore, and nonmetallic mineral), and the fifth group repre-senting the quarrying or opencut mining of minerals whether metallic or nonmetallic. Twenty-seven mines were included in the anthracite group, 68 in the bituminous group, 52 in the metal group, 24 in the nonmetallic-mine group, and 166 in the quarry and opencut-mine group. The total of 337 mines and quarries was 26 more than the number of plants that completed the contest during the previous year.The committee of award which determined the winners of the contest was composed of seven members, all known throughout the mineral industry but not connected with the United States Bureau of Mines. The committee included W. H. Cameron, managing director of the National Safety Council; William Green, president of the American Federation of Labor; James F. Callbreath, Secretary of the American Mining Congress; T. T. Read, Vinton professor of mining of Columbia University and editor of Mining and Metallurgy; C. B. Huntress, executive secretary of the National Coal Association; A. J. Curtis, assistant to the general manager of the Portland Cement Association; A. T. Goldbeck, director of the bureau of engineering of the National Crushed Stone Association."

Jun 1, 1931

By Northcutt Ely

This volume summarizes mining and petroleum legislation in 45 African jurisdictions. Within these jurisdictions, primary attention is given to requirements that must be met in each country for acquisition of rights to permit development of mineral resources. Coverage includes: First, identification of the controlling laws or statutes governing minerals acquisition and reference to the administrative authority; second, analysis of the laws governing mines and quarries and their products; third, analysis of laws applicable to natural gas, petroleum, and related materials; and fourth, mention of laws regulating offshore operations. Where pertinent, sections dealing with historical background or administration have been added. In countries where minerals are subject to control of states or provinces, those areas are considered separately from the central government.

Jan 1, 1974