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By Patrick D. Plumb

The Bureau of Mines (BOM) has begun a project to increase the understanding of the relationships between ecosystem health and its functions, and minerals development. The BOM, Juneau Branch, Alaska Field Operations Center, is providing support for ecosystem based land-management decision-making and the development of ecosystem based regulations by documenting the effects of mining on ecosystems and demonstrating the tools used to assess and analyze those effects. This is done by reviewing the data available on ecosystems and the environment at a mining site, the Greens Creek Mine near Juneau, Alaska, and applying available Geographic Information System modeling tools to assess the impacts of the mine on components of the pristine ecosystem. Habitat Capability Models for wildlife indicator species are used in this examination. Wildlife indicator species are used as indicators of ecosystem health by the U.S. Forest Service and the Alaska Department of Fish and Game, who developed these models for southeast Alaska. Analysis techniques from the U.S. Fish and Wildlife Service's Habitat Evaluation Procedures (HEP) are also used in this report. By applying available models and analytical techniques to the Greens Creek area, the benefits gained through mitigation of potential impacts become apparent. These or similar techniques are useful for cost/benefit analysis of mitigation alternatives. Also apparent from this analysis is that the degree to which potential impacts are observable will depend upon the ecosystem scale considered. This demonstrates the importance of defining the ecosystem and scale before performing impact and cost/benefit analysis. The watershed scale is found to be useful for assessing impacts to ecosystem components at the Greens Creek Mine. Much progress remains to be made in the modeling and prediction of impacts to ecosystems from mining activity.

Jan 1, 1994

By Leonard Obert

This report describes the development of a dynamic strain gage and a companion amplifier and recording camera -an apparatus designed to pick up and record the strain waves produced in rock by a nearby explosion. Also included in the report is a discussion of the relationships connecting the strain with the displacement, velocity, and acceleration for both plane and spherical waves. The proposed tests for which the strain gages were intended required making measurements in solid rock, a factor that necessitated the development of a gage that could be inserted and anchored in a small-diameter diamond-drill hole. The restriction on the diameter of the drill hole is required so that the presence of the hole in the medium will not influence the propagation of the strain wave. The gage should respond with fidelity to the frequencies present in a wave pulse generated by the nearby detonation of a small quantity of high-velocity explosive. Preliminary tests showed that this frequency range extends from 200 to 10,000 c.p.s. or greater. Also, the gage should be capable of measuring strains ranging from a few micro-inches per inch to several thousand micro-inches per inch. Other desirable design specifications included a low gage output impedance to permit the use of long cables, and a low gage cost, particularly in view of the fact that for the final design none of the gages can be recovered from the medium.

Jan 1, 1949

By Thomas C. Denton

The Old Reliable copper mine was first examined by Harlow D. Phelps , an engineer of the Bureau of Mines , in October and November 1942 , in compliance with a request from the War Production Board , which furnished copies of assay maps of the 100- and 200-foot levels and requested that they be check-sampled . The author and R. li. Grantham and W. D. Hughes , engineers of the Bureau , made a second and more detailed examination later , after a number of manways had been opened that were inaccessible when the first examination was made .

Feb 1, 1947

By E. L. Garton

An active list of permissible explosives was published in July, 1931, as part of United States Bureau of Mines Report of Investigations 3134, under the title of "Active List of Permissible Explosives and Blasting Devices Approved Prior to June 30, 1931." Changes in that list were authorized in August, September, October, November, and December, 1931, and January and March, 1932, as published in Reports of Investigations 3140, 3147, 3150, 3155, 3158, 3161, and 3163, respectively. By these changes the following explosives were added to the active Permissible list: Austin Red Diamond No. 1, L. F. Gel-Coalite W, L. F;" Austin Red Diamond No: 5. Gen-Gel No. 2. Black Diamond Nu-Gel No. 1 Genite C-1 Burton 1, L. F. Liberty No 4 Burton 2, L. F. Liberty No. 5 Burton 10, L. F. Peerless D Burton 12, L. F. Permigel 1, L. F. Burton F, L. F.

Jan 1, 1932

By R. A. Guereca

The Bureau of Mines conducted an analysis to determine criteria for steady-state, laminar flow boundary conditions for a coiled-tube gas viscosimeter by comparing experimental data from a thick-walled, stainless steel capillary in a horizontal, straight-tube condition, with similar data taken after the same capillary was formed into a helix. Overlapping volumetric f10wrates and pressure drops are covered for both configurations at pressure levels of 28, 225, and 1,000 psia at 3000 K. Friction factor, Reynolds number, and Dean number correlation plots show conditions where the coi1ed-tube flow deviates from straight-tube flow. The coiled-tube data indicate departure from Poiseui11e steady-state laminar flow at a Reynolds number close to 390 and a Dean number of about 15. Below these conditions and consistent with the data reported, Dean's circulation appears negligible. For the particular coil used, a conservative upper limit of 10 is chosen for the Dean number corresponding to an upper limit of about 250 for the Reynolds number.

Jan 1, 1967

By M. M. Jones

Natural brines are potential domestic resources of minerals. The brines of Searles Lake, CA, for example, contain an estimated one-fourth of our current reserve of tungsten. A key to Bureau of Mines research to recover this critical mineral is the ability to quantitatively measure concentrations of particular constituents in the large number of brine samples and process solutions produced under a multiplicity of test conditions. This paper describes procedures used to determine arsenic, boron, phosphorus, silicon, and tungsten in these solutions by simultaneous inductively coupled plasma spectrometry. A variable in-ternal standard method was used to compensate for tungsten interference on the other analytes in tungsten concentrates, and matching standards were used to determine tungsten in raw brine. Other solutions were analyzed using normal techniques. Analytes were determined down to 1 mg/L with an average precision of 2.5 pet relative standard deviation. Accuracy, estimated using synthetic solutions and by comparison with values obtained by other methods, averaged about 2.5 pet. The methods were rapid, required little sample preparation, and provided the needed sensitivity.

Jan 1, 1985

By W. L. O'Brien, E. A. Rowe

Electrorefined vanadium with additions of up to 5 percent by weight of yttrium, cerium , lanthanum , praseodymium, neodymium, and samarium was melted to ingots in a nonconsumable electrode arc in a helium atmosphere . The ingots were rolled into strips and evaluated for the effect of the alloying elements on hardness , tensile strength , ductility , recrystallization temperature , and microstructure . Except for samarium , average additions of alloying elements of 1 to 2 weight - percent resulted in the retention of 0.12 to 1.05 weight - percent in the alloys and reduced the ultimate tensile strength from about 48,000 to approximately 30,600 psi . The corresponding yield stress (0.2 percent offset ) was reduced from about 40,700 to approximately 20 , 200 psi . Diamond pyramid hardness (DPH) was reduced from 117 to an average of 62 kg /mm² . Increased malleability at room temperature resulted with yttrium and all rare - earth- metal additions , except samarium , particularly with more than 0.25 weight - percent additions . Decreasing oxygen contents corresponded with the changes noted in the mechanical properties of the alloys . The recrystallization temperature of electrorefined vanadium was reduced from approximately 950 ° to 800 ° C. Yttrium or a rare- earth metal content , except samarium , in excess of 0.1 weight - percent in vanadium produced a second phase suggestive of an eutectic which indicated a possible maximum solubility of less than 0.1 weight - percent for both room and elevated temperatures .

Jan 1, 1964

By Charles L. Ross

A successful placer mine is being operated by the E. T. Fisher Co. on Rock Creek in the South Pass mining district at Atlantic City, Wyo. About 2,800 cubic yards of gravel is dug daily by a gasoline-driven dragline shovel with a 1 1/4-yard bucket and washed in a movable plant with a gold-dredge trommel and standard-dredge sluice boxes; the total cost is about 12 cents per cubic yard. The gold-bearing gravel occupies a narrow valley between two low ranges, of hills. The ground is covered by brush and willows, which are cleared of in the fall by burning after the leaves have dried. The elevation at the mine is 7,600 feet above sea level.

Jan 1, 1935

By V. R. Miller

The Bureau of Mines investigated methods for testing the tensile and sheer strength of cast specimens of bulk solder and of soldered joints in order to increase the strength and extend the useful temperature range of soft solders. A spread-area test for determining the wettability of solder on copper surfaces was developed. Mannitol was used as a flux in spread tests to control spreading and to avoid plating, etching, and other side effects of regular fluxes. Data on commercial and high-purity solders obtained by these methods show more consistency than those reported by others from similar tests.

Jan 1, 1967

By L. E. Dalverny

This Bureau of Mines report describes the deployment, 5-month operation, and lessons gained from a continuous gas monitoring system using sampling-tube bundles at an underground mine fire in West Virginia. Research information gained indicates the utility of relating certain gas concentration ratios to events during fire development, mine reventilation, and mine recovery. In addition to monitoring the quality of remote fly ash seals, the system provided timely warning of dangerous gas concentrations which developed during surface and underground recovery activities. An evaluation of system components is supplemented by recommendations for improvements.

Jan 1, 1975

By Daniel D. Sweeney

The United States coal mining industry has traditionally experienced difficulty in controlling dust levels below the occupational exposure limit. While improvements in face ventilation and water spray nozzles have decreased dust exposures, approximately eight percent of experienced coal miners are still developing Coal Worker?s Pneumoconiosis. This investigation tested the feasibility of enhancing existing engineering dust controls by mounting a simple barrier on a longwall shearer that separated the operators from the cutting drums. The barrier was constructed and tested above ground at the National Institute for Occupational Safety and Health Pittsburgh Research Laboratory longwall gallery test facility. A 96-percent reduction of respirable dust occurred at the headgate sampling position when tested at 2.4 m/sec (480 ft/min). The average dust level decreased from 39 mg/m3 to 1.5 mg/m3 by utilizing the barrier.

Jan 1, 2009

By W. P. Yant

[At the majority of mines where flame safety lamps are used either as working lights or as a means of detecting gas, no check it made on this condition of the various parts of the lamp and their assembly other than a visual ink inspection. Although this inspection should be made carefully in view of tae serious consequence that may follow Vie use of a faulty lama, In many instances the inspection is of a perfunctory nature. The Bureau of Mines has therefore designed a small box or gallery for testing lamps for defects and improper assembly before they are taken into the mine. The test simulates the condition when a lamp is extinguished by its introduction into an explosive mixture and the operator attempts to relight the wick while the lamp contains the explosive mixture. This test is more rigorous than merely subjecting a lighted lamp to an explosive methane-air mixture. In the latter test the products of combustion tend to blanket the propagation of flame from within the lamp to the exterior, especially if there are defects at the top of the gauzes. Moreover, when the lighted lamp is subjected to an explosive methane-air mixture the methane builds up slowly within the lamp until the lower inflammable limit is attained, whereupon a feeble explosion occurs within. If the nonlighted lamps is first filled with the methane-air mixture that gives the maximum violence and is than ignited, the dampening effect of products of combustion is obviated and the strain on defects is]

Jan 1, 1930

By W. H. Kerns

The Critchfield manganese deposit, Huntingdon County, Pa., was investigated by the Bureau of Mines in October 1942. Iron ore was mined from an open cut just southeast of the manganese deposit about 80 years ago. The Critchfield Sand & Feldspar Co. was operating (1942) a clay-mining and beneficiation plant northeast of the manganese deposit. The Bureau completed six rotary bucket-drill holes and three hand-auger holes, aggregating 370 feet on the deposit. This report describes the work performed and presents the results obtained.

Jan 1, 1948

By A. B. Hooker

All State mining laws require that flame safety lamps be used in gassy mines; the laws of some States require that safety lamps be kept for emergencies at every coal mine, whether gassy or nongassy. The use of the flame safety lamp has been widespread because it is the only defice readily available for detecting both the presence of methane and deficiency of oxygen. This paper reports the results of an investigation by the Electrical Section, in cooperation with the Gas Section, of the Pittsburgh Experiment Sta¬tion relative to the behavior of permissible flame safety lamps in mine atmospheres deficient in oxygen and the effects of methane5 on the detection of Oxygen deficiency.

Jan 1, 1937

By A. B. Hooker

All state mining laws require that flame safety lamps be used in gassy mines; the laws of some States require that safety lamps be kept for emergencies at every coal mine, whether gassy or nongassy. The use of the flame safety lamp has been widespread because it is the only defice readily available for detecting both the presence of methane and deficiency of oxygen. This paper reports the results of an investigation by the Electrical Section, in cooperation with the Gas Section, of the Pittsburgh Experiment station relative to the behavior of permissible flame Safety lamps in mine atmospheres deficient in oxygen and the effects of methan5/ on the detection of oxygen deficiency.

Jan 1, 1937

By Victor E. Kral

"SUMMARYFollowing a magnetometer survey on the McCoy iron deposit, a trenching and drilling program was carried out by the Bureau of Mines in August 1944.This deposit is 32.3 miles southwest of Battle Mountain in the McCoy Mining District, Lander County, Nevada, and lies on the east flank of the Fish Creek Mountains at an altitude of 5,400 feet, about 1 1/2 miles south of the gold camp of McCoy.Total production from the deposit has been 400 tons of magnetite, mined by hand and shipped to the west coast for ship's ballast.Bureau drilled two holes to a total depth of 92 feet and excavated 12 feet of trenches. Both holes were drilled in the same ore body and engineered magnetite ore 14 and 11 feet thick. Trenching was used successfully to show the lateral limits of the ore.Magnetite ore bodies were found to occur as replacements of a limestone bed in quartzite. They outcrop near and parallel to the exposure of a diorite entrusting that forms a long westward-trending ridge. Although magnetic outcrops can be traced for 5,000 feet trenching definitely proved the ore bodies to be disconnected to have little or no lateral extent beyond their outcrops. Only two ore bodies more than 10 feet thick were found; one of these is the inaccessible to and the other was drilled by the Bureau."

Jan 1, 1947

By H. B. Freaman, C. L. Colburn, C. M. Bouton

"The mine telephone has been perfected to such an extent that it is giving satisfaction in most mines were the wiring is well insulated. Very often the telephone cannot be depended upon on account of falls of rock, grounding due to worn insulation or extreme dampness. In the event of a disaster it frequently happens that the mine telephone system is put out of commission by the agency that causes the disaster, at the time when it is most urgently needed. On this account the mining industry is interested in any kind of telephone system that can be counted upon in an emergency. Many requests have been received by the Bureau of Mines to devise means of utilizing wireless methods for this purpose.The results of some preliminary experiments conducted by the writers at the Bureau of Mines experimental mine at Bruceton, Pennsylvania, in the ordinary sending and receiving of radio waves through earth strata are described below. The experiments were made in cooperation with the Westinghouse Electric end Manufacturing Co., which assigned to this work three of its radio engineers, C. A, Boddie, E. C. Douglas, and F. D. Fessler,The preliminary experiments consisted first in receiving signals from without the mine by means of a receiver located inside the mina, and second, both sending and receiving messages underground through the strata. It was found that with a receiving instrument set at a point 100 feet underground, signals from KDKA station, of the Westinghouse Electric and Manufacturing Co. East Pittsburgh, Pa., could be heard distinctly. Station KDKA is at a distance of about 18 miles from the experimental mine. About 50 feet from the receiving station used in this test was a 6-inch bore-hole from the surface, lined with iron pipe and containing electric light wires which extended therefrom through-out the mine. The presence of these wires evidently assisted greatly in the reception, for when the receiving set was carried to another point in the mine removed from wires and tracks the signals were barely audible through 50 feet of cover. The fact that signals were detected, however, even though faintly, is sufficient evidence of transmission through the ground to encourage further experimenting.In sending waves underground the Westinghouse 20-watt B.T. model T.F. transmitter was used in such a manner as to send out continuous waves of 200 to 300 meters length."

Oct 1, 1922

By Thomas A. Morgan, Louis A. Panek

This report describes a method for determining the stress in rock based on a requirement for static equilibrium ; namely , that the total load on a sufficiently large area must remain constant even after a drift or stope is mined in the area . The method is based on mathematical relationships that are independent of the elastic properties of the rock and the stress distribution near the underground opening . In addition to determining the preexisting stress (before mining ) , the method described can be used to determine the change in stress due to mining .

Jan 1, 1963

By Wesley A. Grosh

The Toncrae-Howard copper deposits in Floyd County, Va., were first mined about 1800. The property has been operated or under development at various times since then for iron, copper or sulfur, although the total production has been small. The deposit consists of a vein or zone of sulfide mineralization in schist composed mainly of pyrrhotite with minor copper values in the primary zone and some rich areas of copper mineralization in the altered zone. The Bureau of Mines, in an attempt to develop minable copper ore during the war, opened part of the mine for examination and sampling, deepened the shaft and other underground work, and drilled 29 holes totaling 2,187 feet.

Jan 1, 1948

By R. V. Ramani, W. Miola

"A relationship exists between the quartz contents in the underground coal nine airborne dust samples and those in the coal and host rocks that are mined [17, 18, 19] The prescribed method for quartz analysis in respirable airborne coal dust samples is the MSHA P-7 method. Accurate quartz analysis procedures are needed for bulk samples in order to predict the potential quartz content in airborne nine dust, which in turn will aid the design of quartz dust control procedures during mining. thereby reducing the airborne quartz dust in underground atmospheres. The requirements of this method are that the amount of quartz is the sample be less than 250ug, and the total sample weight less than 2,500 ug. Unlike with airborne dust samples, there are no limitations to the available mass of bulk samples. However, these are no standard procedures for the preparation of bulk samples for scanning or prescribed methods for quartz analysis. The NIOSH and MSHA methods are certified for roped* dust and the acceptance of these methods for bulk samples assumes that the bulk samples will be reduced to the conditions specified for respirable dust samples. An alternative method is X-ray diffraction, which provides higher average quartz values than those obtained from P-7 method for the same samples.An investigation was carried out to determine the optimal procedure for preparing the bulk samples for the IR and XRD analyses. In this paper, the investigations on the effects of calibration, particle sizes, matrix composition, interferrous, and behavior of the filter substances on IR, XRD and FTIR results are presented. The error introduced by the presence of kaolinite and a new sample asking procedure to reduce it are discussed. The problems experienced with conventional sample holders for scanning were eliminated with the design and development of a new hollow sample holder. Quantitative comparison of quartz determinations by IR, XRD and MR methods on coal, roof and floor rocks, and airborne dust samples are presented. The important factors affecting the results of quartz analysis methods are: 1) bulk sample preparation for obtaining representative and homogeneous analysis samples: 2) particle size distributions of the analysis samples and calibration standards; 3) qualitative matrix composition of the analysis sample; 4) matching calibration standards to analysis sample; 5) substrates for sample deposition during analysis sample preparation; 6) procedures for analysis sample mounting; 7) selection of proper portions of she response profile for insanity measurement; and 8) interferences of spurious phases with the critical analyses. The recommendations of this study are important to enable comparisons and interpretations of analysis and research results."

Nov 1, 1995