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By F. Garacia, J. Cervik

Gob holes are routinely used by the mining industry to vent methane from gobs and to prevent it from entering the mine ventilation system. In some cases, flows from gob holes are measured by centering an anemometer on the end of a discharge pipe. These measurements are erroneous and tend to be high by as much as 30 pct. The Bureau of Mines deter- mined method factors (correction factors) for anemometer measurements taken in this manner. Method factors for 4-, 6-, and 8-in (10.2-, 15.2-, and 20.3-cm) ID pipe are 0.68, 0.71, and 0.78, respectively. Comparisons between horizontal and vertical flows indicated no significant change in method factors. Consequently, the method factors for horizontal pipe flows can be applied to vertical upward flows.

Jan 1, 1987

By E. W. Newman

The Bureau of Mines, in cooperation with the U. S. Geological Survey, developed the property of the Tungsten Metals Corp. by surface trenching and diamond drilling from November 1940 to June 1941 and from August 1943 to December 1943. The purpose of the work was to determine possible reserves of tungsten in the downward extension and lateral eastern extension of three major tungsten-bearing quartz veins. The property is 50 miles south of Ely, White Pine County, Nev., in the Minerva Mining District. Tungsten ore was discovered in the district in 1915, and mining started in 1916. The tungsten ore bodies occur as shoots in quartz veins that occur along faults in limestone. With the exception of a small-scale leasing operation in 1932, the property was idle from 1919 until 1936, when Tungsten Metals Corp. was organized to acquire the mines. Production ceased in May 1945, and the mines were idle until leased in 1947. Development by the Bureau of Mines during 1940 and 1941 consisted of surface trenching, sampling, and diamond drilling 37 holes for a total of 6,959 feet. Subsequent drilling of eight holes, totaling 3,067 feet, in 1943 disclosed additional reserves. This report sets forth in considerable detail the exploration work completed by the Bureau and briefly describes the mining and milling methods employed. Diamond-drill halo logs and sample analyses are shown graphically in the illustrations that accompany the report.

Jan 1, 1950

By D. I. Bleiwas

Bureau of Mines personnel evaluated the potential availability of nickel from 151 deposits in 18 market economy countries and selected 126 for detailed analyses. An evaluation was made of tonnage-cost relationships indicating the quantity of nickel available at various total costs of production expressed in dollars per pound nickel, including a 15-pct rate of return on the invested capital. The 126 deposits studied contain approximately 73 million metric tons (t) of nickel. An estimated 52 million t is available from laterite deposits, of which less than 2 pct could be produced at $3.50/lb Ni, about equal to the average published price of nickel in 1981. Approximately 21 million t of nickel is available from sulfide deposits, of which about 10.0 million t can be produced at $3.50/lb. Sensitivity studies performed for both laterite deposits and sulfide deposits indicate that the total cost of nickel from laterites is most sensitive to increases in energy costs, and that sulfides are most sensitive to increases in labor costs; sulfides are also sensitive to changes in byproduct revenues. In 1983 the Nickel Mountain mine in Oregon was the only U.S. producer, though development continued on the Gasquet property in California. Of the total 5.1 million t of recoverable nickel in the United States, about 20 pct is available at or below $3.50/lb.

Jan 1, 1984

By H. H. Schrenk, L. B. Berger, W. P. Yant, F. A. Patty

"The use of small such as canaries and white mice, for detecting carbon monoxide depends primarily on the fact that the volume of respiration of these animals in proportion to their volume of blood is much higher than for man. Accordingly, when animals and men are simultaneously exposed to a given concentration of carbon monoxide the animals will absorb it more rapidly and attain serious poisoning in less time than men. Prom a practical viewpoint the use of the animals depends on the margin of time between observable symptoms in them and serious poisoning in man, during which man can return to fresh air or use respiratory protection. It should be remembered, however, that during the time the animal is incurring a detectable degree of poisoning, man is also absorbing some carbon monoxide, and the margin of time is not very wide. Experience with canaries has shown that an occasional specimen may have a tolerance above the average of the species and fail to exhibit symptoms before man incurs a very discomforting and possibly a serious degree of poisoning.It is also well known that physical activity increases the demand for oxygen by the body, and the respiratory exchange and circulation of the blood are increased to meet the demand. This sets up a vicious condition if carbon monoxide is present in the air because the rate of absorption of carbon monoxide is not only increased by the increase in respiration and circulation, but the absorption of carbon monoxide decreases the capacity of the blood for carrying oxygen at a time when the demand is high. These facts, together with the increase in respiration and circulation which attend excitement, underlie the caution to be calm and to walk slowly and to reduce physical exertion to a minimum when exposed to carbon monoxide. For these same reasons, when using animals for detecting carbon monoxide it is endeavored to keep them active, thereby tending to increase the response of the birds and widen the time between observable effects in the birds and effects in the man. As rule canaries are kept fairly active through fright at the unnatural surroundings and in their endeavor to remain on the perch of the cage when carried into the atmosphere to be examined. They also experience an excitement stage with oncoming carbon monoxide poisoning. Sometimes, however, especially if the air is cold, they tend to be inactive and quiet. Ordinary mice and white mice become inactive with use and also with oncoming poisoning. They huddle in the corner or the cage, and thereby not only reduce their sensitivity but make it difficult to observe signs of poisoning."

Oct 1, 1930

By E. W. GOODWIN, V. F. Parry, J. B. Goodman, L. D. Schmidt, J. D. Davis, A. C. Fieldner, W. S. Landers, J. L. ELDER

The Heliopore process is essentially an arrangement that uses the waste heat in the exhaust gas of an internal - combustion engine to carbonize coal (noncaking ) or lignite . The gases distilled from the coal furnish fuel for the internal - combustion engine , which drives an electric generator . Thus the main products of the plant are electricity and char . A flow diagram illustrating the principles of operation of the Heliopore process is given in figure 1. The primary equipment consists of a carbonizing retort , gas cooling and scrubbing equipment, a gas storage holder, and an engine to burn the gaseous carbonization products . Coal is charged into the top of the retort while the hot gases from the engine travel upward through special ducts in the retort countercurrent to the coal flow . The hot gases never come into direct contact with the coal . Char is discharged at the bottom of the retort and hot gases at the top . The gaseous products resulting from carbonization of the coal are drawn off by an exhauster through the condensing and scrubbing equipment to take out tar and liquor , then to a gas holder , and finally are burned in a gas engine . The gas engine drives an electric generator and the engine exhaust gases are returned to the retort to carbonize coal . The entire process was intended to be continuous and self - sustaining, and to use coal as the only fuel . The plant may be said to be a large - scale pilot plant in that , although it is of full commercial size , its main purpose is to provide data for the design of others of its type . The installation tested had a daily throughput of about 4 tons of coal . Figures 2 , 3 , and 4 picture some details of the plant and equipment used in the experimental testing . Further details of the equipment and engineering drawings of the castings are shown in figures 8 to 22 in the Appendix .

Dec 1, 1943

By Francis X. Cannaday

The Bureau of Mines developed equipment to measure the sonic velocity of pulses transmitted through rock samples varying in size from laboratory specimens to mine pillars in place. Pulses are produced by electronically excited piezoelectric ceramic transducers. Special equipment components were developed by Bureau facilities; other components are commercially available. The technique permits a nondestructive, repetitive, stable, shaped pulse to be used in place of explosive caps or hammer blows. Longitudinal wave travel time measurements were taken on an oscilloscope screen; transverse wave measurements were taken under special field conditions. Results were consistently repeatable within the accuracy of the oscilloscopes utilized.

Jan 1, 1966

By Q. H. Forbes

"The high injury rand fatality rate in coal mining, as compared with other industries, has caused the mining industry to become more and more interested in accident prevention methods.The prevention of accidents in the mining industry is probably not as simple a problem as it is in other industries, but if the experience of coal mining companies who have taken up the work of accident prevention seriously during recent years means anything, there is little doubt that most mining companies car improve their accident records very materially.Such results can be obtained in practically all instances without adding to production costs. In fact, there is little doubt that a well-organized program of accident prevention Will bring about a 'material production cost reduction due to increased efficiency, lower labor turnover, fewer delays due to accidents, better satisfied workmen, and a direct saving in compensation costs as well as many other items of expense.The more closely a. person is connected with the work of accident prevention, the more he becomes a believer in the value of amity in human relationships and the more he is able to exercise a spirit of toleration, fairness, justness, and helpfulness toward the problems of others, whatever those problems may be. Human nature responds to just these expressions of good willAnother great and invaluable effect of working for safety, is the fact that it is building up in the mind an appreciation of that which is constructive and, conversely, in opposition to that which is destructive In other words; the person who is sincerely striving to prevent accidents because they are destructive, costly, tad injurious, is subconsciously training his mind to look on any proposition from a constructive point of view. Working for accident prevention and safety is about the finest social training any person can have. It does not make a Person a financial Wizard or an executive genius, but it does make for the highest type of citizenship.While humanitarian reasons alone should be sufficient to maze accident prevention work an important factor in every mining organization, there are other reasons as well, since it has been proved conclusively that there can be no efficiency and economy without safety, as somebody pays when safety is lacking. Every safety device pays dividends; every safety application evaded is an assessment and a loss. Dangerous conditions are the most expensive and extravagant conditions in or about a coal mine. The economic gains are of considerable interest to all coal mining companies and this is brought about as before stated--through decreased compensation rates, the reduction of labor turnover, etc."

Dec 1, 1930

By Fredrick L. Johnson

In 1984, at the request of the U.S. Forest Service, the U.5, Bureau of Mines began a study of the 94,370-acre Arc Dome study area (4-667) in order to appraise its mineral resources, The Bureau of Mines mapped and sampled mines, prospects, and mineralized sites in and near the area, The study area is located in the Toiyabe National Forest, about 54 mi north of Tonopah, Nye County, NV, It is estimated that over 500 claims have been staked in the study area since the mid-1800?s. In January 1986, there were 108 active mining claims completely inside and 59 on the boundary. Another 283 active claims were outside the study area but within 1 mi of the boundary, In addition to the large number of claims staked, exploration activity is also reflected by the almost 700 inactive workings that were found during field investigation.

Jan 1, 1989

By Walter D. Holland

LFE Environmental performed an Industrial Hygiene survey of the Paraho Oil Shale Mining and Processing facility in Anvil Points near Rifle, Colorado, on August 6 and 7, 1975. This survey consisted of an investigation of the underground operations for diesel emission contaminants and of the above ground work areas for all inhalation contaminants other than silica dust. Samples were collected to investigate the following contaminants: respirable dust, total dust, NO2, NO, H2SO4, formaldehyde, CO2, S02 and CO. None of the determinations of contaminants in the underground operations indicate air concentrations exceeding their standards. The results for the samples collected above ground indicate only one operation where the employee's exposure exceeds the standards. It is a welding operation where the standards for total dust and lead are exceeded. Since the survey the employer has installed an exhaust ventilation system which has significantly reduced the welder's exposure.

Jan 1, 1976

By Robin B. McCulloch

No producing mines are in the study area. Sample results indicate the only resources in the study area are low grade phosphate deposits associated with Cuyama Phosphate Mine (fig. 1). Within the study area, are more than 21.4 million tons of inferred subeconomic phosphate rock resources which would be reserves at an 80 percent higher phosphoric acid price; weighted average grade is 4.84 percent phosphorous pentoxide (P205). About 17.6 million tons of similar grade are outside the area to the northwest. The South Cuyama Oil Field, adjacent to the study area (fig. 1), produces petroleum from the Vaqueros Formation which underlies parts of the study area. Oil and gas potential was evaluated by U.S. Geological Survey. INTRODUCTION Location, Size, and Geographic Setting The U.S. Bureau of Mines conducted a mineral survey of the Fox Mountain RARE II area (No. 5120) during the summer of 1981. The area was examined to determine the presence or absence of mineral resources and reserves, and to estimate tonnage and grade where possible.

Jan 1, 1982

By H. E. Hilliard

The Bureau of Mines investigated hydrometallurgical procedures for concentrating precious metals from a mechanically processed metal fraction of obsolete military electronic scrap. Feed material for the leaching procedures described in this report was the high-tension-separated metal concentrate obtained as a fraction from mechanically processing partially stripped electronic units. Initial pretreatment with a 20-wt-pct-NaOH solution solubilized most of the aluminum. After washing, the resulting residue was incinerated to destroy any organics attached to metal particles. The incinerated residue was leached with 20-vol-pct H2S04 solution using two methods, countercurrent pressure and ultrasonic-aided leaching to solubilize the base metals, predominantly copper. Silver was recovered from the base metal leach residue using 50-vol-pct HN03, and gold contaminated with several percent palladium was recovered from the silver leach residue using aqua regia. The impure silver and gold plus palladium products represent about 1.5 wt pct of the high-tension-separated metal concentrate. Included is a three-step process evaluation study of mechanical processing of general electronic scrap and two hydrometallurgical procedures for leaching high-tension-separated metallic concentrates obtained from the mechanical processing step. Process evaluation concluded that only mechanical processing is economically viable.

Jan 1, 1985

By McHenry Mosier

This paper describes the practice in diamond drilling blast holes and discusses the relative merits of this method as compared with drilling by percussion rock-drills at eastern magnetite mine A. The rooke that were drilled included: (1) Gneiss; (2) sohist; (3) crystalline limestone; and (4) granular masses of magnetite. The principal stoping methods were: (1) Sublevel open stoping and (2) inclined room-and-pillar. Diamond drilling was used in the sublevel stopes and in some of the large pillars in an old section of the mine. Experimental work on diamond drilling blast holes began in 1943. Drill- ing proved difficult owing to the occurrence of fingers of extremely hard barren rock in the magnetite ore. All diamond drilling was contracted to a firm that furnished everything necessary for drilling except compressed air and water. In most instances the diamond-drill machine is clamped directly to a 3.5-inch column to reduce vibration. For drilling in floor pillars in open stopes, the drill was set on a demountable, sectionalized steel, frame with four legs carrying a 20-foot, 3.5-inch, extra-heavy pipe. "Both coring and noncoring bits were tried. In holes drilled with a cor- ing bit, the core was ground into sludge as the bit advanced so that it was unnecessary to delay drilling for pulling core. Data on tests with several types of bits are given as well as some oper- ating results. A direct comparison of costs between diamond drilling and percussion drilling was not available. The advantages of diamond drilling blast holes at mine A included: (1) Safer working conditions in open stopes. (2) The recovery of additional ore. (3) A reduction in the amount of stops development.

Dec 1, 1946

By C. P. Mishra

The Bureau of Mines performed a study of the availability of cobalt from market economy countries. The study entailed the detailed analysis of 97 deposits which contain 3.9 billion lb of cobalt at the demonstrated level; in 94 of the deposits cobalt is recovered as a byproduct, and in 3 it is considered the primary product. Since 97 pet of all recoverable cobalt is derived as a byproduct from copper and nickel deposits, the report focused on these two sources. At an assumed market price of $0.89flb for copper, $3.45/lb for nickel, $475/tr 021 for platinum, and $7/lb for cobalt, 1,330 million lb of cobalt at the demonstrated level are potentially available. This total includes 1,105 million lb of cobalt from copper properties, 190 million lb from nickel, 29 million lb from platinum, and 6 million lb from primary cobalt. This analysis indicates that the production cost for 589 million lb of cobalt can be totally covered by the revenues obtained from the other metals produced. The impacts of increases in capital investment and energy costs are also discussed.

Jan 1, 1985

By A. E. Sands

The Bureau of Mines, S. Department of the Interior) at, its Morgantown., W. Va., station, operating under a cooperative agreement with West Virginia University, is conducting research and development work on the problem of producing synthesis gas from coal. An important part of this work is the study of the gas purification necessary to meet the rigorous standards required to render the gas suitable for use in the Fischer-Tropsch synthesis of liquid fuels. One of the most detrimental impurities is sulfur in all forms, the maximum amount that can be tolerated being one-tenth of a grain per hundred cubic feet. Concentrations as low as this require the use of precise analytical methods to evaluate the performance of processes used for removing sulfur. At the same time the analytical methods should be rapid in order to reveal the failure of purification before damage to the expensive synthesis catalyst results. Although sulfur in unpurified gas is generally present as hydrogen sulfide and as organic sulfur compounds, the latter may be converted to hydrogen sulfide for analytical purposes. Thus a suitable method for the determination of traces of hydrogen sulfide may also be used for the determination of organic sulfur.

Jan 1, 1949

By O. C. Ralston

Natural or artificial manganese dioxide of a grade pure enough to be satisfactory as depolarizer for dry cells has never been available in large supply simultaneously with being available in desired quality . The Second World War called for more of it than ever . A supply of natural material from the Gold Coast was ample for the war and was not completely exhausted . Whereas the crystal form of the manganese oxide was not recognized as a matter of importance until the war came , it is now known that gamma MnO2 is a desirable form and that pyrolusite , once thought acceptable , is not the best mineral . The following paper is a translation of an internal company report filed at the Bitterfeld office of the I. G. Farbenindustrie A.G. by Dr. Peter Marx in 1933 , just a year after G. W. Nichols had published in the Transactions of the American Electrochemical Society a study of making anodic manganese dioxide from solutions of manganous sulfate . The I. G. experiments were made to confirm the American work and were also extended to a larger scale . Only chemical purity was considered , and no mention is made of crystal form . The report adds to the knowledge submitted by Nichols but has not been previously available to the general public . Believing it of value to the United States industry , a translation has been made .

May 1, 1948

By H. E. Powell

This study was made to determine the capabilities and limitations of the hydrocyclone for separating quartz sand from impure clays, Optimum operating conditions for beneficiating typical subgrade clays were determined. Estimates are furnished for installation and direct operating costs of hydrocyclones in such separations. Laboratory models of commercial hydrocyclones were used to beneficiate a suite of fire clays including plastic, semiflint, and flint types, all of which were contaminated with quartz in amounts ranging from 3 to more than 62 percent. Results show that this technique is not limited to a single type of clay but is applicable to clays ranging from plastic through flint, Under proper conditions use of this technique will result in good separation of the sand and good recovery of a useful clay mineral concentrate. Rejection of quartz from the clays investigated ranged from a low of 82.4 percent with an alumina recovery of 71.2 percent to a high of 99.0 percent with an alumina recovery of 85.6 percent.

Jan 1, 1963

By G. W. Jones

In cooperation with the Edison Electric Illuminating Co. of Boston, Mass., and the Boston Consolidated Gas Co., a survey has been conducted continuously since 1929 by the Bureau of Mines to determine the general hazards of combustible gases and vapors in manholes of the Edison Electric Illuminating Co. The New England Telephone & Telegraph Co. also has cooperated in the investigation, and tests have been made in its manholes since May 1, 1933. Yearly reports6/ on the results obtained since the beginning of the survey have been published. The method and procedure of conducting the survey in 1936 were the same as heretofore.

Jan 1, 1938

By G. W. Jones

In cooperation with the Edison Electric Illuminating Co. of Boston, Mass., and the Boston Consolidated Gas Co., a survey has been conducted continuously since 1929 by the Bureau of Mines to determine the general hazards of combustible gases and vapors in manholes of the Edison Electric Illuminating Co. The New England Telephone & Telegraph Co. also has cooperated in the investigation, and tests have been made in its manholes since May 1, 1933. Yearly reports6/ on the results obtained since the beginning of the survey have been published. The method and procedure of conducting the survey in 1936 were the same as heretofore.

Jan 1, 1938

By O. C. Blade

The southeastern region of the United States is becoming more important as a petroleum-producing area, and it is receiving increasing attention from oil operators. In 1948 total production of crude oil from six southeastern States - Alabama, Florida, Kentucky, Mississippi, Tennessee, and Virginia - was 55,244,000 barrels, which represents 2.7 percent of the Nation's output during that year. Kentucky and Tennessee have produced crude oil since the early days of the industry, but the remaining four States have had production only few years. Data on annual production of crude petroleum in the six States are given in table 1.

Jan 1, 1950

By A. B. Hooker

[Permissible electric cap lamps represent a workable balance between the amount of light needed and the various limiting conditions, such as the weight the miner can carry conveniently, cost of the lamp, including upkeep, and adequacy or practicability of the lamp as regards safety, mechanical strength, and general performance. Other things being equal, the coot desirable lamp is one that gives the greatest amount of useful light. Conversely, with a given amount of light the most desirable lamp is one that its the most efficient respecting weight, cost, and performance.]

Jan 1, 1935