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By David A. Monaghan, Kenneth R. Maser, Adi R. Gurdar, D. Randolph Berry

3. Preliminary Evaluation of Mine Sealing Techniques As the first stage in the development of a technique for the remote sealing of mines, a state-of-the-art survey of various mine sealing techniques was conducted. This was expanded to include a review of different materials offering some potential for use as a mine sealant. Techniques for the remote placement of materials for other applications were evaluated, and system concepts for dis¬tributing remotely placed materials were developed. This preliminary review led to the development of a functional description of a general mine sealing technique to meet the specified conditions. Various potential system configurations were synthesized. These were subjected to a preliminary evaluation based on estimated confidence in system performance, development risk, cost, and sealing time. Based on this preliminary evaluation, promising mine¬sealing techniques were selected for further development. This section presents a review of the following: (a) Techniques for constructing permanent seals from within a mine. (b) State of the art in remote sealing for mine fire control. (c) Techniques for remote placement of materials for other applications. (d) Systems for distributing remotely placed material. (e) Materials for mine sealing. (f) Synthesis of remote mine sealing concepts.

Jan 1, 1973

By Jr. Smith

The equilibrium compositions of product gases for mixtures of air with methane, propane, or ethylene at and around flame temperatures are reported. For each hydrocarbon, compositions are given for five fuel-to-air ratios--two lean, two rich, and one stoichiometric--at five pressures, from 1 to 20 atmospheres, and at an ambient temperature of 25° C.

Jan 1, 1965

By S. J. Aresco

The Bureau of Mines has been active in promoting the purchase of coal for Government use under specifications that define the requirements in terms of heating value of the coal, expressed in British thermal units, and the composition as shown by proximate analyses. To these, when required, are added the ash-softening temperature, the free-swelling index, and the Hardgrove grindability index. Under most of these specification contracts the bidders guarantee the quality of the coal, and that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled in accordance with instructions5/ issued by the Bureau of Mines; the samples are analyzed in the Bureau laboratory to determine whether the coal is of the quality guaranteed by the contractor and, if it is not, a price adjustment is made. Analyses of the delivered coal and tipple samples (samples collected at mine tipples as coal is being loaded into railroad cars or trucks) provide valuable data for use in evaluating future bids. In addition, the continuous sampling of coal as delivered is a check on the practical results obtained in burning the coal.

Jan 1, 1961

By Thomas J. Peters

The U.S. Bureau of Mines conducted a mineral investigation, and the U.S. Geological Survey did a geological appraisal of an east portion of the Bear-Marshall-Scapegoat-Swan (BMSS) RARE II area (No. A1485) to provide mineral resource information for land use planning. The Bureau of Mines' investigation consisted of a library and field search for all mineral properties and occurrences, and included a review of Teton County mining claim records. Those records showed two placer claims, the only mining-related activity known in the area. Six reconnaissance pan samples were taken in the vicinity of the two placer claims, the Lone Star and Spotted Horse, located on Hannan Gulch in 1900 and 1901. One sample contained a trace of gold, but there are no identified resources. However, the study area is in the Rocky Mountain Overthrust Belt, which is productive for oil and gas elsewhere. The entire study area is blanketed by oil and gas leases and is currently being explored.

Jan 1, 1983

By J. S. Gomer

The U.S. Bureau of Mines conducted Cu exchange tests for six common clays under simulated in situ leaching conditions. Regression equations were obtained from the data expressing the Cu exchange capacity as a function of Cu concentration, pH, and temperature. Using these equations, an analysis was made of the impact each clay could have on overall Cu recovery. The results suggest that Ca and Na montmorillonite clays could have a major impact on Cu recovery and that attapulgite and illite clays could have a smaller, but still significant, impact. Kaolinite and ripidolite clays pose little threat to loss of Cu from in situ leaching solutions.

Jan 1, 2010

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 Foster Fraas

The response of minerals in magnetic separators is in accordance to dynamic rather than static magnetic susceptibility values . The dynamic value varies with respect to both passage speed through the separating field and time of exposure in a preliminary treatment field . Tests on 16 minerals and solids have demonstrated that both of these factors affect different minerals in different ways .

Jan 1, 1964

By G. S. Scott

It is sometimes desirable to know what changes in sizing characteristics would appear in screened coals if screens of different - size openings than those employed had been used . This report is concerned entirely with the application of the Rosin- Rammler law to a solution of this problem .

Dec 1, 1943

By E. G. King

THIRD-LAW entropy data for zirconium-containing compounds are sparse. Kelley a lists entropies at 298° K. for the oxide, tetrachloride, nitride, and silicate, as well as for the metal. The present paper presents heat capacities between 51° and 298° K. and entropies at 298.15° K. for the zirconates of the alkaline-earth metals-calcium, strontium, and barium. The authors believe magnesium zirconate does not exist as a stable compound at room temperature. Entropies of formation from the constituent oxides also are given. MATERIALS The materials used in this investigation were synthesized and analyzed in the Berkeley Laboratory of the Bureau of Mines. Calcium zirconate was prepared by heating an intimate mixture of reagent-grade calcium carbonate and pure zirconia for 30 hours between 1,200° and 1,300° C. and for 32 hours between 1,400° and 1,500° C. As part of the heating schedule, the sample was ground and mixed seven times. Periodic analyses and minor adjustments of composition were made. Analysis of the final product gave 31.19 percent calcium oxide (theoretically 31.28 percent) and 68.67 percent zirconia (theoretically 68.72 percent). The X-ray diffraction pattern agreed with that in the ASTM catalog.

Jan 1, 1960

By Doris M. Hyde

To a greater or lesser extent, the economies of the smaller Caribbean Island countries continued to have common problems. These included unemployment, inflation, foreign exchange shortages, trade deficits, and unstable world prices for their exports. Declining prices for petroleum provided some relief from scarce foreign exchange. Overall, the mineral sector remained stable. The Amerada Hess Corp. crude oil transshipment terminal on St. Lucia was completed during 1981. However, there were no shipments during the year. No official reason was offered for the delay in opening the terminal, but it may have been related to the world surplus of crude oil that occurred in 1981. There has been no further action on the refinery, which was to complete the island's petroleum complex. During the first half of 1981, an announcement was made that a second oil transshipment terminal would be built on St. Lucia. The report indicated that the terminal was to be financed by Saudi Arabia and include underground storage. After the original announcement, no further information was made available. This terminal, like the Hess petroleum complex, may have been temporarily postponed because of the crude oil surplus.

Jan 1, 1983

By W. W. Adams, V. E. Wrenn

"Production of explosives in the United States during the calendar year 1935 decreased 2 percent from 1934, according to reports covering all companies engaged in the manufacture of explosives during those years.Reports from manufacturers showed a total production of 308,381,250 pounds of explosives; this quantity included 39,170,016 pounds of permissible explosives 5/ 200,323,559 pounds of high explosives other than permissibles, and 68,887,675 pounds of black blasting powder of which 34,222,625 pounds were granular powder and 34,665,050 pounds pellet powder.Coal mines consumed 89 percent of the total production of blasting powder, 99 percent of the total output of permissible explosives, and 11 percent of the output of other high explosives.The metal mines of the United States used 28 percent of all high explosives other than permissloles, less than 1 percent of all permissibles, and 1 percent of all black powder produced.Quarries and nonmetallic-mineral mines consumed 17 percent of the high explosives other than pormissibles, less than 1 percent of the permissible., and 3 percent of the blasting powder.Construction work required the largest quantity, 40 percent of all high explosives manufactured during the year. Less than 1 percent of the permissibles and 6 percent of the black powder produced during 1935 was used in construction work."

Nov 1, 1936

By R. Hogg

"The basic population balance models for agglomeration processes are reviewed and procedures are described for extending their applicability to systems with size-dependent rate constants and to the formation and growth of porous agglomerates from rigid, solid-particles. Simplified procedures for the further extension of the models to include simultaneous agglomerate growth and breakage are also described.INTRODUCTION The association of small particles into clusters or agglomerates is a significant factor in many facets of particle processing. Agglomeration processes are widely used to facilitate handling, storage and utilization of fine powders. Processes such as coagulation or flocculation are used to aid solid-fluid separation in dispersed particulate systems. Agglomeration also occurs as an accompaniment, often unwanted, to other particulate processing operations such as fine grinding, mixing and blending, transport and flow.Reliable agglomeration models are needed for improved understanding of the processes in general and of the complex role of numerous, interacting variables as well as for direct application to the design and control of industrial processes such as flocculation, granulation and pelletization. Ideally, the models should account for the primary forces responsible for agglomerate formation and growth, the effects of external forces on process dynamics, the development of agglomerate structure and its role in the process itself, and the effects of concurrent processes such as structure modification (e.g. compaction) and agglomerate breakage or degradation."

Jan 1, 1989

By R. Hogg

"The basic population balance models for agglomeration processes are reviewed and procedures are described for extending their applicability to systems with size-dependent rate constants and to the formation and growth of porous agglomerates from rigid, solid particles. Simplified procedures for the further extension of the models to include simultaneous agglomerate growth and breakage arc also described. IntroductionThe association of small particles into clusters or agglomerates is a significant factor in many facets of particle processing. Agglomeration processes are widely used to facilitate handling, storage and utilization of fine powders. Processes such as coagulation or flocculation are used to aid solid-fluid separation in dispersed particulate systems. Agglomeration also occurs as an accompaniment, often unwanted, to other particulate processing operations such as fine grinding, mixing and blending, transport and flow.Reliable agglomeration models are needed for improved understanding of the processes in general and of the complex role of numerous, interacting variables as well as for direct application to the design and control of industrial processes such as flocculation, granulation and pelletization. Ideally, the models should account for the primary forces responsible for agglomerate ·formation and growth, the effects of external forces on process dynamics, the development of agglomerate structure and its role in the process itself, and the effects of concurrent processes such as structure modification (e.g. compaction) and agglomerate breakage or degradation.In its most general form, the process of agglomeration involves taking discrete, independent particles, bringing them into contact with one another, promoting (or allowing) interparticle adhesion to occur and then causing structure rearrangement, usually under the action of external forces. The relative importance of these steps varies with the nature of the particulate system being agglomerated and with the kinds of agglomerates being produced. Coagulation or flocculation of particles dispersed in fluids is generally dominated by the contact and adhesion steps. In the granulation of powders, on the other hand, particles are already in contact so that structure rearrangement is the principal step."

Mar 1, 1992

By E. D. Gardner

"The town of Ajo is built in the desert and consisted of but a few houses when the New Cornelia Copper Co. started operations. Since there were no stores at Ajo or vicinity the New Cornelia Cooperative Mercantile Co. was established to serve the needs of the employees of the New Cornelia and allied companies.The New Cornelia Copper Co. advanced the money to erect the store building and to buy the stock, and assumes all risks. In all, $85,000 has been advanced, representing the capital stock of the enterprise.The store is run by a store manager appointed by the Copper Company and who reports only to the general superintendent. A committee of seven workmen, representing the various depart¬ments, meet with the store manager monthly and make suggestions for the betterment of the service and, present complaints which have been brought to their attention.The store is well managed, carries a large and well assorted stock and is modern in every respect. Prices are at the same level as in the other Southwestern mining camps. The Copper Company does not particpate in the profits of the store but does receive six per cent interest on the capital advanced. At the end of the year, after making proper deductions for interest on capital account, depreciation of store equipment and fixtures, and, for a proper sum to the surplus account, the rest of the profits is distributed among the employees of the company in proportion to the amount of their purchases."

Aug 1, 1920

By H. G. Iverson

The effects of adding boron and boron plus carbon to electrorefined vanadium were evaluated with respect to mechanical properties at low temperatures and response to heat treatment. Grain size was significantly decreased with the addition of 0.05 percent boron, the decreases ranging from 30 percent at 800° C to 75 percent at 1,100° C. Increasing the boron content resulted in only a small increase in strength at room temperature, but at 77° K, boron contents of 0.005 to 0.076 percent increased the yield strength of vanadium over 50 percent, from 70,000 psi to 110,000 psi. When boron and carbon were present together, the individual grain-refining effects obtained with either element were retained. Approximately a twofold increase in strength was obtained by age-hardening the alloys containing both boron and carbon. Alloys with only boron additions did not age-harden.

Jan 1, 1968

As part of remote sensing research on an abandoned mine lands (AML) site in the Colorado Springs, Colorado area, a geographic information system (GIS) database was generated. This GIS database contains information on the locations and extents of abandoned underground coal mines, the geology of the area, subsidence features and degrees of subsidence risk, topography, drill hole locations, and lineaments (linear features) related to subsurface geologic structures. A GIS database allows the reproducible and accurate comparison and analysis of any data sets which geographically overlap and are within the same coordinate system. The database has been released to the public domain so that government agencies, researchers, educators, and the general public can access this coherent database for the purposes of better understanding the study area and GIS technology. Data files and maps are available in formats that are compatible with the GIS software used in the research project and with most CAD systems so that as many people as possible can make use of the majority of the database. This document serves as the data dictionary for the database by providing descriptions and origins of the data files.

Jan 1, 1992

By A. B. Hooker

Many attempts have been made to develop methane detectors that will be safer and more accurate than the flame safety lamps used to detect methane in mines. The development has taken two general forms, namely: (1) Methane detectors, in which the evidence of methane depends entirely upon changes in the appearance of the detecting element, such as a flame or filament; (2) indicating methane detectors or those equipped with scales upon which the approximate percentage is definitely indicated. As an aid in the development of suitable detectors, the United States Bureau of Mines has assembled and published in its Schedule 8B a set of minimum requirements which tests and experience have shown desirable for methane detectors. Any manufacturer may submit his detector for inspection and tests leading to approval under this schedule.

Jan 1, 1930

By X. C. Shi

Bacterial mutagenicity and mammalian cell chromosomal and DNA damage in vitro assays were performed on a diesel exhaust particulate material (DPM) standard in two preparations: as an organic solvent extract, and as an aqueous dispersion in a simulated pulmonary surfactant. U.S. National Institute for Standards and Technology DPM SRM 2975 expressed mutagenic activity in the Salmonella reversion assay, and for in vitro genotoxicity to mammalian cells as micronucleus induction and as DNA damage in both preparations: as an acetone extract of the DPM mixed into dimethylsulfoxide, and as a mixture of whole DPM in a dispersion of dipalmitoyl phosphatidyl choline. Dispersion in surfactant was used to model the conditioning of DPM depositing on the deep respiratory airways of the lung. DPM solid residue after acetone extraction was inactive when assayed as a surfactant dispersion in the micronucleus induction assay, as was surfactant dispersion of a respirable particulate carbon black. In general, a given mass of the DPM in surfactant dispersion expressed greater activity than the solvent extract of an equal mass of DPM.

Jan 1, 2009

By M. C. Malamphy

A general description of the activities and results of bauxite investigation by the Bureau of Mines at its bauxite project in Saline and Pulaski Counties, Ark., has been given in Report of Investigations No. 4251. The factual data obtained during the project are reported in a series of Reports of Investigation beginning with No. 4251, of which this is the sixth. The data are accompanied by maps showing the loca.ion of holes, drilled and the deposits developed. Each area upon which work was done is reported by half townships. Each bauxite deposit investigated was assigned a name and a number for ready reference and identification, and its location and name are shown on the appropriate half-township map. The description of each half township is followed by a description of each deposit developed in that half township. The 14 half-township maps and 77 detail maps of the bauxite deposits in this series of reports give the locations and numbers of all the holes drilled on the project except the deep holes drilled to test geophysical anomalies. The locations of those holes are shown on figure 13 in Volume I. The descriptions of the deposits developed are followed by complete detailed logs of the drill holes. Many of the widely spaced exploratory holes did not discover bauxite of minable thickness and grade. The pertinent information obtained from the widely spaced exploratory drill holes has been summarized and tabulated, and a table for each half township is given with the discussion covering that area.

Jan 1, 1948

By E. C. Lane

This paper is a preliminary report of the results of the Bureau of Mines' twenty-second semiannual survey of motor gasoline marketed in the United States. A more detailed discussion of the whole survey is in preparation and will be published as a companion, report. The second paper, in addition to giving a more complete summary of the data included in this report, will present results of the determination of copper-strip core lion (method 530.22), color (method 10.11), sulphur content (method 520.11) evaporation residue (method 530.1), and gum content as given by the Bureau of Mines steam oven method.9 The retail price at the time the sample was taken and tax will also be stated for each sample. The present paper deals specifically with data relating to gravity, vapor pressure, and distillation. It has been the feeling of some investigators that the practice, followed in previous semiannual surveys, of grouping all types of motor fuel together without discriminating between "competitive price gasoline," benzol blends, Ethyl gasoline, "high-test" fuels, etc., has detracted from their usefulness because the data did not permit drawing conclusions in regard to any one type of fuel, and tended to obscure differences between fuels of the various types. Therefore, in order to remedy this condition, the samples of the present survey have been divided into two groups; one called "competitive-price gasoline" and a second group called "premium-price motor fuels."

Jan 1, 1930