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By Robert D. Perry

This report describes methods of reclaiming abandoned or inactive tailings ponds and dams. The investigated sites were selected tailings deposits adjacent to metal mines in the southwestern United States and the Pacific Northwest. The basic data developed for each site consisted of the following: a review of existing literature: a site visit that included sampling of the tailings and surrounding materials; laboratory and engineering studies; and development of reclamation plans. Laboratory tests determined the gold and silver content of each tailings deposit and the chemistry of the tailings and surrounding materials. Reclamation plans that include approximate costs were developed for five tailings deposit sites. These ranged in size from 52,000 to 103,000,000 tons. Our conclusions on the remining potential of each site are based on the tailings assay and other technical data. This study concludes that remining as a reclamation tool is feasible at certain sites. Included in this report is a remining program as part of the overall reclamation plan for two sites. Our preliminary results indicate that remining as a reclamation tool is feasible for only one of them.

Jan 1, 1981

Develop a method to evaluate the effectiveness of coal scam fire surface seals so that potential problems may be corrected at an early stage, before the integrity of the surface seal is lost. Background Surface seals are the primary coal seam fire abatement method being used in the western United States. Surface seals smother a fire by denying it oxygen. The seal is usually constructed by placing a mantle of soil, four to ton feet thick, over a coal scam fire area to exclude air from the fire. The soil is compacted to increase effectiveness, and a soil cement may be used to augment the soil. In some cases, burning coal may be excavated and separately smothered or otherwise extinguished in another area; in other cases, a trench maybe excavated and backfilled with incombustible material to isolate a fire. More often, a surface seal is simply applied over and around the entire known burning area. In the 1950's, the Bureau of Mines administered a large program to treat numerous coal seam Fires across the western United States. Methods used in this program were described in Bureau of Mines Information Circular (IC) 7932, dated 1959. More recently however, various coal seam fires have been treated with surface seals under the direction of state Abandoned Mine Land Reclamation authorities. It has frequently taken years to evaluate the effectiveness of surface seals. By the time problems become evident, it has often been too late to take corrective action within the scope of the original abatement project. For this reason, the Bureau of Mines developed a means for tracking temperature trends at coal seam fire projects to obtain a better and earlier handle on the effectiveness of surface seals.

Jan 1, 1991

By Lisa A. McDonald

The environmental compliance process affects all aspects of hardrock-mining operations, from exploration through post-closure. The primary components of the environmental compliance process are requirements under the National Environmental Protection Act of 1969 (NEPA) and the permitting requirements associated with various other federal, state and local laws. This study considers the Greens Creek Mine and the development of two other projects (Alaska-Juneau & Kensington). These mines were used as the foundation for a case study of the impacts of the environmental compliance process on hardrock-mining activity in Southeast Alaska. The case study presents the institutional and legal requirements, followed by a discussion of the impact of this process on the production and timing of the three mines. The results of this preliminary study reveal some interesting findings, some expected and others unexpected, regarding the impact of the permitting process on the exploration, development and (proposed) operation of the three mining projects in the Juneau area. Determining the cost of compliance with these requirements is an important step in evaluating the appropriate course of action to protecting the environment while providing the necessary raw materials needed for society. This preliminary study highlights the initial starting point for such an analysis.

Jan 1, 1992

By T. M. Barczak, S. C. Tadolini

Reduction in the recovery time required and improvements in safety during a longwall face move have compelled coal mine operators to examine and use pre-driven longwall recovery rooms. The recovery entry is developed at the longwall stop position and supported ahead of time so that the required combinations of standing and internal supports can be installed before the longwall face approaches. A calibrated three-dimensional finite element model, developed in conjunction with an underground test area, provided the critical components and design principals for a comprehensive parametric study. The study indicates that vertical, horizontal, and shear stresses concentrated on the outby abutment pillar corner of the recovery room resulting in deformations in the immediate roof above the primary roof support anchorage level. The results of the numerical model and field site observations indicated that the combination of the internal bolting system and the standing concrete supports are critical for the successful and safe extraction of the longwall equipment. Cable supports installed at and angle over the pillars can help stabilize the disturbed zone above the adjacent fender and outby pillars, however; standing supports are required in most sedimentary roof conditions to increase stability and assure a safe longwall extraction.

By W. L. Staker

The Bureau of Mines investigated methods for selectively eluting mercury, silver, and gold from strong-base anion-exchange resins, including Rohm and Haas resins lRA-430 and 900 and Dow Chemical resins 2lK, SMA-I, and SBR. Resins were typically loaded to 145 oz/st of each metal. Loaded resins were eluted with H2S04, NaCl-H Cl, NaOCl, and NaCl04 solutions. The resins tested had similar elution characteristics for mercury and precious metals. The best selective elution scheme was achieved by eluting in a column with 2N H2S04 to recover 99 to 100 pct Hg, with 200 giL NaCl in IN HCI to rec;ver 99 to 100 pct Ag, and with 2M NaCl04 to recover 79 to 89 pct Au.

Jan 1, 1987

Although the technology involved in removing material from below the earth's surface has a long history, communication systems in underground workings are relatively new to the industry. Communication equipment did not begin appearing in underground mines until the early 1900's. Figure 1-1 shows a miner using a Western Electric standard telephone set for underground mines in 1913. These early phones were essentially the same as those used aboveground, except that they were enclosed in cast-iron boxes as protection against moisture, acid fumes, and gases.

Jan 1, 1984

By E. P. Youngman

By a decree of March 14, 1929,5 the President of the Faitian Repub- lic, considering it to be necessary, until the mining legislation of the Republic shall have been revised, to put into effect the mining law of Decem- Der 4, 1860 (relative to mines, diggings, and quarries), by the authority given in article 55 of the Constitution, declared the law of February 14, 1919, to be abrogated and the provisions of the earlier mining law (December 4, 1050) again to be valid. No concessions were granted under the law of 1919. All citations in this paper, unless otherwise designated, refer to the law of 1930.

Jun 1, 1932

Provide the National Park Service (NPS) with guidelines for closing abandoned mine openings such as shafts and adits. Approach The NPS needed alternative methods of closing a variety of abandoned mine openings on National Park lands. Because the U.S. Bureau of Mines (USBM) has a long history of mining-related experience, the NPS requested that the Bureau provide them with technical mine closure information. USBM engineers compiled information on various types of mine closures and prepared technical illustrations of those closure techniques. Multiple closure options, by type of opening, were prepared as one-page field guides to assist NPS field personnel in determining the most appropriate closure method for a given situation and detailing the construction of the closure method. Results Guidelines provided to the NPS included a description of the method, use applications, construction techniques, technical illustrations, and technical support information. The following provides a brief description of 11 mine closure techniques identified for use by NPS personnel. Most of the closure methods, except the backfill methods, allow for construction that can provide access to the mine. However, providing access makes the closure susceptible to vandalism. Most closure methods require periodic monitoring for subsidence and corrosion or deterioration of construction materials.

Jan 1, 1994

By Stephen C. Tadolini, Peter (Yunqing) Zhang

A unique circumstance created by monitoring a pre-driven longwall recovery room permitted measuring the stresses of a coal pillar throughout its entire life cycle in less than a week. A fender pillar, created in approximately the middle of a longwall panel at a depth of 650 ft, transformed from a solid barrier pillar - to a yielding pillar - to a residual pillar as 3 ft slices were methodically removed with the longwall shearer. The complete transformation, or life cycle, took place in less than 12 hours. The stresses were quickly transferred from the pillar onto the standing pumpable concrete supports and into the outby pillars. Roof to floor closure measurements, combined with the timing of the pillar behavior, provides a detailed look at the uncontrollable convergence of underground mine openings. Pillars remain the most important form of “primary support” and understanding these life cycles is vital for safe and efficient mine design, in both room and pillar and longwall panel extractions.

By R. E. Kennedy

"INTRODUCTION In a previous publication4 results were given of numerous experiments made on the in-flammability of gas mixtures consisting of methane, hydro a. carbon monoxide, nitrogen, and carbon dioxide. Data were obtained and tables prepared giving the inflammable limits of each of these combustibles when mixed with various proportions of carbon dioxide and nitrogen. By the use of these data and the application of Le Chatelier's law, it was found possible to calculate the limits of inflammability of any gas mixture containing any or all of the above gases.Various mixtures of the five gases given above were prepared and their limits determined experimentally and then calculated. Good agreement was found between the determined and calculated results when complex gases encountered in mine safety work were tested. Of special significance was the accurate calculation of the limits of inflammability of gases from mine fires, gases from mine explosions, detonation products of explosives, blast—furnace gases, automobile exhaust gas, and other gases of a similar character.Using the method given in the above report, Yeaw5 investigated a number of industrial gases including oven, coal, producer, blue, carbureted blue, and dry quencher gases, and found the determined and calculated results to agree remarkably well, thus giving further proof of the value of such a means of determining dangerous conditions when combustible gases are encountered in practice.GASES FROM A POTASH MINEGases were recently encountered in a potash nine in New Mexico, containing the com-bustibles, methane, hydrogen, and ethane. In one special case a mild explosion occurred when these gases were mixed with the right proportions of air and ignited it therefore became necessary to know the inflammability of these mixtures in order that the proper precautions could be taken to prevent explosions."

May 1, 1932

By L. Nahai

Iran's petroleum industry is nearly 50 years old and the oldest in the Near East. According to published figures, Iran ranks third in production and reserves in the Near East. These reserves (including probable reserves) are estimated at 35 billion barrels and constitute about 11 percent of the world's total. Iran is the sixth largest producer of crude petroleum in the world. The 1961 output of more than 430 million barrels was 5 percent of total world out-put for the year. In the same year, Iran ranked fourth among world petroleum exporters, providing 8.4 percent of total world exports.

Jan 1, 1963

By S. M. Shelton

[The widespread occurrence of domestic manganese deposits and the shortage of ferromanganese-grade ore have been sources of much speculation and investigative effort for many years. The present emergency has intensified the search by the Bureau of Mines for methods of producing ferromanganese-grade concentrates4/ from low-grade ores.]

Jan 1, 1941

By Bertrand L. Johnson

Barite, the natural sulfate of barium (BaSO4), is the most important barium mineral. Normally it is white (opaque to translucent), but impurities sometimes render it yellow, gray, blue, brown, red, or black. Brown or red stains are commonly caused by iron oxide. Barite is unusually heavy (specific gravity, about 4.5); in fact, it is one of the heaviest of the nonmetallic minerals. It is brittle and fractures unevenly. The hardness of barite ranges from 2.5 to 3 but is usually about 3. It can be scratched by a copper coin. Pure barite contains 65.7 percent BaO and A.3 percent S03. Much of the crude barite ore mined, however, contains impurities; thus it has a lower content of barite and consequently less barium oxide. Commercial analyses show its total BaSO4 content. Barium also occurs in nature as the mineral witherite (BaCO3), which, however, is not common in the United States, and commercial deposits have been found only in California. Witherite is a yellowish-white, light-gray, or Kite mineral with a specific gravity of about 3, a hardness of 3 to 4, and an uneven to subconchoidal fracture.

Jan 1, 1941

By Constantine C. Popoff

During 1946 several high-grade limestone deposits in western Washington were examined by the Federal Bureau of Mines. The purpose of the examinations was to disclose new sources of industrial limestone and to indicate the commercial potentialities of little-known and undeveloped deposits. These examinations were part of a long-range program of investigation of mineral resources of the Pacific Northwest. The following report on the Whitechuck travortine deposit is one of a series prepared in the course of the investigations.

Jan 1, 1949

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

APPENDIX A - PNEUMATIC TRANSPORT OF FLY ASH 1. Introduction Two types of pneumatic transport of fly ash are critical to the success of (1) Transport of fly ash from the fly ash truck to the entrance to the borehole. Depending on the surface topography, this may be horizontal, decential and ascential. (2) Vertical downflow of fly ash through the borehole. All fly ash trucks have limited pressure with which they can pump the fly ash. Thus, the pressure drop in the fly ash hose will define the maximum length for pumping and consequently the maximum distance that the fly ash truck can be parked from the auxiliary blower. The same relationships describe the flow of the dilute fly ash-air mixture produced by mixing with the auxiliary air from the blower and thus define the selection of the pipe diameter. These are im¬portant considerations in the proper selection of the location of the passages to be sealed and the type of surface preparation required. The flow characteristics of fly ash down the borehole determine the selection of the minimum borehole diameter and the blower pressure. This appendix presents theoretical analyses of these flow regimes and summarizes the limited experimental data obtained during the field tests at Grant Town, described in Section 8.4. The analysis for the borehole flow is presented first as it is of greater interest to the program. This is followed by a discussion of the horizontal flow.

Jan 1, 1973

By Terry P. Medhurst, Stuart A. MacGregor, Peter J. Hatherly

In addition to fractures and joints, compositional factors and bedding influence the strength of clastic sedimentary rocks. Rock mass rating schemes must therefore consider all of these factors. In this paper, a rating scheme for clastic sediments based on geophysical measurements is described. Geo-physical logging allows an approximation of rock com-position to be obtained and an assessment of bedding frequency and laminations. Velocity measurements incorporate the effects of fracturing. The rating requires scores for the intact rock, bedding/cohesion, and defects. These are combined to yield a Geophysical Strata Rating (GSR). Determination of the GSR is objective and repeatable. GSR values are typically between 20 and 80 and can be related to the Coal Mine Roof Rating.

Jan 5, 2007

By F. D. Stevenson

Thermodynamic properties of metal halides and, in particular, vapor pressures have become of great importance in recent years owing to increased application of chemical processing to extraction of metals from their ores. Vapor pressure data serve not only as a valuable source of latent heat of vaporization and fusion values but also differences in metal-halide vapor pressures often provide the basis for their separation by conventional mass transfer operations. This literature search was made to provide a ready reference to experimental vapor-pressure data of metal halides and oxyhalides. Results are reported in two main sections: (1) A tabulation of vapor- pressure references for each of the metal halides (listed by metal) for which actual experimental data are reported (table 1), and (2) a bibliography of the citations. Metal halides and oxyhalides are listed by chemical formula and chemical name, based on the stock4 system. To facilitate location of the references, a listing of the journal titles and their abbreviations follows the bibliography.

Jan 1, 1963

By A. J. Miscoe

A unique machine for inducing bending fatigue in wire ropes was built at the U.S. Bureau of Mines' Pittsburgh Research Center. This machine can produce nine levels of degradation through repetitive cycling of long samples of wire ropes of the types used in the mining industry. This report provides an analysis of the results of the first wire rope to be fatigued on this machine. These results have indicated that as a wire rope accumulates bending cycles, its strength first decreases because of wear and then in-creases due to cold working of the wires. As the amount of cold working increases, more and more of the embrittled wires break and the strength of the rope decreases rapidly. In this test, application of several of the regulatory retirement criteria to various sections of the rope suggests that there may be some inconsistency among them.

Jan 1, 2010

By James A. Wasson

This report summarizes the results and conclusions reached by various investigators who have attempted to determine the extent to which hydraulic fracturing will affect the secondary recovery of crude oil by waterflooding. It also discusses the most advantageous use of this well-stimulation method in waterflood projects. A thorough search of the literature was made, and pertinent information was abstracted from appropriate reports. A carefully designed and controlled program of formation fracturing is an effective aid in waterflooding because it increases water-injection and oil-production rates. Generally, fracturing has resulted in little or no reduction in ultimate oil recovery, but under certain circumstances recovery has been substantially increased.

Jan 1, 1963

By John Durkin

Electromagnetic narrow-band signals were transmitted through the earth at 27 coal mines located throughout the United States. From those Bureau of Mines tests, apparent earth conductivity values were derived based upon a homogeneous half-space model of the earth. The derived conductivity values were found to be inversely proportional to the transmitted frequency and mine depth. A linear regression model relating the logarithm of the conductivity to the mine depth was formulated, and the results indicate that the mine depth can be an adequate predictor of the apparent earth conductivity above coal mines. Apparent earth conductivity was found to decrease with mine depth.

Jan 1, 1984