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By W. M. Merritts

The control of coal dust created and released during the operation of continuous mining machines in bituminous-coal mines of the United States is a problem. The interest manifested in this problem indicates the seriousness of the hazards involved, particularly when the dust has not been abated at its source and has become air-borne. Officials of the Sunnyside No. 1 mine, Kaiser Steel Corp., were confronted with the problem of abating the coal dust created by operation of a recently installed continuous-mining machine, and they requested the aid of representatives of the Coal-Mine Inspection Branch, Bureau of Mines, United States Department of the Interior, in developing an effective method of allaying the coal dust at its source.

Jan 1, 1951

By Wm. W. Adell

"These hydrocarbons belonging to the same chemical series as methane, having the general formula CnH2n have many chemical properties in common with methane and their addition to a lean gas charges the properties and burning characteristics of the gas in the same general direction although to a different extent. The hydrocarbons of this series do not readily enter into chemical reaction with other substances and therefore are incapable of combining with oxygen or polymerizing in the disturbing system and thus cannot cause gum and room troubles commonly met with in the distribution of manufactured gas.As the number of carbon atoms in the molecule increases, i.e. in proceeding from methane throughout the series, the oxygen requirements for the complete combustion of unit volume of the gases also increases; in other words, the calorific values of these hydrocarbons (as gases) increases from methane. Similarly the specific gravity increases from methane in the same order. In Table 1 are shown some of the physical constants and properties of a few of these hydrocarbons which hive bearing on their use for enriching gas."

Nov 1, 1927

By D. Randolph Berry

The objective of this program was to develop a system to extinguish coal mine fires by remote sealing of the underground passageways. The system developed had to be versatile enough to function under a wide range of operating conditions, including large variations in passageway geometry, depth of mine, water conditions, both in the mine and at the surface, and rubble in the mine passage. The system developed had to include instrumentation for the remote probing of the passageway prior to sealing, a system for sealing the mine passages, and instrumentation for remote monitoring of the quality of the seal during and after construction. These objectives were successfully achieved during this program. The remote mine sealing capability of the system was satisfactorily demonstrated in a field test conducted at the Eastern Associated Coal Corporation Federal No, 1 Mine in Grant Town, West Virginia.

Jan 1, 1973

By R. R. Wells

This report summarizes the results of preliminary mineral-dressing studies by the Bureau of Mines on five samples of copper-bearing ore from various Alaska de-posits. The work on each sample was not extensive enough to warrant individual publication. The results, however, indicate the possibilities and limitations of concentration of the respective ores. The information therefore may be helpful in future development of these ore bodies. Four of the five samples tested were submitted to the laboratory by engineers of the Bureau of Mines as part of the examinations and survey investigations of strategic-mineral deposits in Alaska. This program is conducted to assist development of mineral resources in the Territory and particularly to aid economic exploitation of marginal or complex ores. The fifth sample was submitted by engineers of the Defense Minerals Exploration Administration.

Jan 1, 1956

By Frank J. Wiebelt

Under a general program to extend the resources of mineral deposits, the Bureau of Mines examined the Quien Sabe antimony mine in October 1948. The preliminary evaluation demonstrated that a diamond-drill program was warranted co establish the tenor and persistence of the veins and permit an estimation of antimony reserves. The Bureau of Mines conducted a diamond-drilling program on the property from December 1949 to May 1950. Ten holes aggregating 2,483 feet were drilled. Nine of the holes encountered antimony-bearing vein material.

Jan 1, 1956

By James J. Olson

This report summarizes the results of a review of foreign coal mining literature conducted under the Bureau's Advancing Coal Mining Technology program. In addition to a discussion on the historical development of mechanized longwall systems, and the current state-of-the-art method in Europe, this report summarizes the previous and ongoing Bureau efforts to adapt longwall technology to U.S. conditions. The bibliographic section of this report, divided into major categories such as mine design, face management, roadway development, strata control, powered roof supports, coal winning, conveying, and automation, contains over a thousand individual entries. The purpose of this report is to provide U.S. mining engineers with background information on longwall methodology and equipment developed in foreign countries (principally Europe). The Bureau of Mines, as part of its Advancing Coal Mining Technology program, is funding R&D projects to demonstrate that the longwall mining method, successfully used in the deep mines of Europe, can boost productivity and improve safety in certain U.S. mines.

Jan 1, 1977

By Wm. O. Vanderburg

This report on the mining and milling of tungsten ores is the second part of a general study of the domestic tungsten industry. The first part, comprising general information on tungsten, has been printed as Bureau of Mines Information Circular 6821. The purpose of these papers is to increase efficiency in the mining, preparation, and utilization of the tungsten resources of the United States. The tungsten industry forms so small a part of the vast mining and metallurgical operations of the illation that private metallurgists have not had enough inducement to give special attention to the recovery of tungsten minerals from the ores, and many of the small companies are financially unable to undertake research work. A study of the milling of tungsten ores reveals that further improvement is possible, especially in the treatment of slimes. Recent experimental work by the Bureau shows that the flotation process is applicable to certain tungsten ores. The future of the tungsten industry it the United States depends to a great extent on utilization of the low-grade deposits of the contact-metamorphic type.

Jan 1, 1935

By C. Melvin Lepper

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

Jan 1, 1982

By Richard Lusignea

A single boom roof bolting machine was outfitted with measurement and recording systems for detecting changes in machine parameters while drilling. The purpose of this instrumented bolter or "smart drill" is to detect changes in roof conditions from the machine parameters of penetration rate, thrust, rotation rate, torque, rejected light from rock cuttings, and vibration of the roof during drilling. The system was demonstrated underground in coal mine conditions and showed correlation between rock type and drilling parameters.

Jan 1, 1982

By W. G. Freeman

This study provides recommendations for improved safety in underground blasting procedures based on in-mine observations of blasting practices in 30 underground metal, non-metal, and coal mines, and the analysis of blasting accidents since 1970 and existing state and federal regulations pertaining to the storage and use of explosives. Results of these analyses and observations indicate that 1) blasting accidents have declined but are an important contributor to the hazards of underground mining; 2) existing regulations are essentially adequate; 3) greater emphases should be placed on human errors and unsafe practices and the enforcement of existing regulations; and 4) future revisions of these regulations and standards should be organized, and their intent coordinated to eliminate ambiguities.

Jan 1, 1980

By Harold M. Smith

Important discoveries of new oil fields were made in 1937 in the State of Illinois. Oil production, which was virtually constant during 1934, 1935, and 1936 at about 4,400,000 barrels a year, a increased to 7,499,000, barrels during 1937, and in 1938 this production was trebled. In 1939, 94,302,0003/ barrels were produced (almost four times the 1938 quantity), making Illinois one of the cost important oil-producing areas in the United States. The Bureau of Mines has analyzed 35 samples of petroleum from these new Illinois fields and presents the analyses herein. Included with them in this report are analyses of seven samples from fields developed before 1936.

Jan 1, 1940

By Harold M. Smith

[Important discoveries of new oil fields were made in 1937 in the State of Illinois. Oil production, which was virtually constant during 1934, 1935, and 1936 at about 4,400,000 barrels a year, a increased to 7,499,000, barrels during 1937, and in 1938 this production was trebled. In 1939, 94,302,0003/ barrels were produced (almost foot times the 1938 quantity), making Illinois one of the cost important oil-producing areas in the United States. The Bureau of Mines has analyzed 35 samples of petroleum from these new Illinois fields and presents the analyses herein. Included with them in this report are analyses of seven samples from fields developed before 1936.]

Jan 1, 1940

By R. R. Wells, G. M. Potter, A. O. Ipsen

This paper gives results of laboratory and pilot - plant investigations of concentration of western manganese ores during the Bureau of mines manganese-development program initiated in December 1940. The data summarize results obtained from laboratory investigation of concentration of ores from three properties in southeastern Arizona . The high - grade Gray - claims lot B ore , a product of hand sorting , is marketable directly or after sintering treatment . Intermediate - grade lot A selectively mined ore would be marketable after sintering as a plus 35 percent manganese produce , but gravity concentration methods were employed effectively to produce high - grade manganese concentrates with over 80 percent recoveries . Complex association of fine - grained manganese oxides , calcite , and fluorite in a siliceous ground mass limited the recovery of high-grade manganese concentrates obtainable from the low-grade Pyrolusite -group ore . A recovery of 63.7 percent of the manganese was made by flotation in a concentrate that sintered to plus 48 percent manganese grade . The low-grade Davis ore contains iron and manganese oxides too intimately associated to permit production of marketable manganese products . However , good rejection of calcite gangue was obtained by flotation , and the enriched manganese - iron product might have value as a spiegeleisen ore .

Feb 1, 1946

By W. W. Adams

"Accidents at coal mines in the United States in September 1926 resulted in the loss of 170 lives, according to information furnished to the Bureau of Mines, Department of Commerce, by State mine inspectors. Of this number 125 occurred at bituminous mines and 45 in the anthracite field. As the bituminous output of coal for September was 48,976,000 tons, and the production of anthracite was 8,444,000 tons, the fatalities reported represented a death rate of 2.55 per million tons for bituminous mines and 5.33 for anthracite mines. The industry as a whole showed a fatality rate of 2.6 per million tons of coal produced in September 1925 the rate for bituminous coal mines was 3.29; the anthracite mines were idle in September last year due to a strike.During the first nine months of the present year 1,759 men have been killed by accidents at the coal mines throughout the United States, resulting in a death rate, per million tons of coal produced, of 3.76 as compared with 3.95 for the same period in 1925. Reports for bituminous mines alone showed a nine-month fatality rate of 3.53 which was about the same as the corresponding rate from January to September in 1925. The anthracite rate for the present year, however, shows a decrease of about 17 per cent; that is, the rate has declined from 6.36 to 5.28.Records covering the first nine months of 1926 show that 12 ""major"" disasters, that is, disasters in which five or more men were killed at one time, have resulted in the loss of 271 lives as against 10 disasters and 199 deaths in the corresponding months in 1925. The fatality rates for these disaster: alone were 0.579 and 0.465, respectively. One major explosion occurred at Tahona, Oklahoma, on September 3, 1926, in which 16 men lost their lives.An analysis of the principal causes of the 1,759 fatalities for the first nine months of the present year shows a reduction in the death rate as a whole and for falls of roof and coal and for explosives, but an increase in haulage, gas and dust explosions, and electricity. The comparative rates for these accidents were:"

Oct 1, 1926

By George J. Conroy

This Bureau of Mines report summarizes the results of a study of mine inspection records covering 2,200 mining installations over a 3-year period ending December 1974. Tables show the relative frequency of violations of certain provisions of the Coal Mine Health and Safety Act of 1969 in particular areas of concern, such as circuit breakers, grounding, and permissibility. Examples of past use of the data and analyses are presented.

Jan 1, 1976

By B. W. Gandrud

In 1927 Coghill showed that there is considerable liberation of the iron oxide mineral from gangue when the Alabama red iron ores are ground to a size suitable for classification and tabling but that there is not sufficient to make possible a high extraction and a high grade of concentrate. Coghill states: High extraction and 'high grade of concentrate cannot be obtained without grinding to a size comparable with flotation or cyanide practice. If grade of concentrate be sacrificed the grinding need not be so severe. These ores slime readily during grinding, and in most instances the slimes are only slightly higher grade than the original ore. Not only do they carry a considerable percentage of the total iron in the ore, so that to reject them as tailings would result in prohibitively low extraction, but they are too fine to be amenable to ordinary methods of gravity concentration. In 1929 the Bureau of Mines published results showing that certain Alabama oolitic iron ores could be concentrated by classification and tabling after grinding, with rubber-covered rods. This selective grinding produced slimes of much higher grade than the original ore, and they were considered part of the final concentrate.

Jan 1, 1934

By Richard J. Bielicki

This Bureau of Mines study estimates the number of major pieces of coal- mining equipment that will be required to produce 950 million tons of marketable coal in 1980 and 1.2 billion tons in 1985. The coal tonnages were projected in the intermediate coal supply scenario of Project Independence Blueprint (PIB). The equipment projections were determined by consideration of historical trends and by evaluation of information from equipment manufacturers and mining companies. The ability of the manufacturers to meet the projected equipment demands was also determined. It was concluded that equipment supply offers no presently discernible constraint to mining 1.2 billion tons of coal in 1985. A shortfall in projected production for the intervening years, however, is probable owing to anticipated shortages of draglines.

Jan 1, 1976

By H. R. Pierce

Bureau of Mines engineers end others have endeavored to deter-nine a fundamental method for gauging the capacity of gas wells to deliver gas under different pressure conditions. Their studies show that for accurate gauging two factors must be determined: (1) The actual pressures at the face of the sand in the well (usually referred to as "at the sand"), acid (2) the relation between such pressures and the rates. of flow of c as through the sand. This paper, the first of a series, describes a method of attacking the problem of determining the actual pressures at the sand by means of observations of pressures and volumes at the well head.

Jan 1, 1929

By H. M. Thorne

The Petroleum Experiment Station of the Bureau of Mines at Laramie, Wyo., in cooperation with the University of Wyoming, has in progress chemical and refining studies of Wyoming black oils. In general, these crude oils are characterized by their high sulphur, high asphalt, and low gasoline content and are called black oils because of these properties and their color. Characteristics of the various Wyoming black crude oils, as determined by the Bureau of Mines Hempel method of analysis, have been published.4/

Jan 1, 1938

By H. M. Thorne

The Petroleum Experiment Station of the Bureau of Mines at Laramie, Wyo., in cooperation with the University of Wyoming, has in progress chemical and refining studies of Wyoming black oils. In general, these crude oils are characterized by their high sulphur, high asphalt, and low gasoline content and are called black oils because of these properties and their color. Characteristics of the various Wyoming black crude oils, as determined by the Bureau of Mines Hempel method of analysis, have been pubished.4/

Jan 1, 1938