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By David A. Newman

Barrier pillars created during mine development provide additional reserves during mine closure and can be the sole access to reserves previously abandoned because of mining height or out of seam dilution limitations. The safe and successful mining of barrier pillars requires a thorough knowledge of the magnitude and distribution of the vertical stress field in addition to the strength and physical properties of the coal, immediate roof, and immediate floor strata. Quantifying the vertical stress field is complicated by the combination of the overburden stress, abutment stresses transferred onto the barrier pillar from adjacent gob areas, and in multiple seam mining, stresses transferred from abandoned subjacent mines. These variables make the extraction and development of barrier pillar reserves a site specific consideration. Three case histories are presented in which barrier pillar development and extraction provides; i) an access point and the means to ventilate a large area of low seam reserves left by a prior operator after developing only the thicker areas of a multiple split reserve, ii) the means to increase total recovery of a deep, thick seam longwall reserve, and iii) opportunities for the development and retreat mining of a two mile long barrier pillar in thick seam reserves.

Jan 1, 1995

By H. C. Miller

"Introduction**The progress of the ""Safety First"" movement in the oil fields of California during the past few years has been remarkably rapid. It has been generally concede by those who have learned to value the life and limbs of their employees, that safety is essential to efficiency and no company that has a high accident rate can be considered an efficient organization. Accidents have a destructive effect on the morale of any body of workers and cause disorganization and delays.The increasing danger to life and limb involved in the drilling for and the production of oil and gas, has become so great that it is clearly evident that everything possible must be done to keep it within the narrowest possible limits.There is a tendency toward carelessness, especially by men who are employed in hazardous occupations. This is brought about by the familiarity of the risk under which they are working and in no industry is this more forcibly exemplified than in the oil fields. Men have performed the same or similar duties for many years and have worked around similar hazards and unprotected machinery until many have can entire disregard for the dangers surrounding then. Very often familiarity with a hazard occasions a contempt for that hazard which only too often results disastrously."

Dec 1, 1923

By J. W. Thompson

This work is a codification and annotation of the Congressional enactments relating to minerals, mineral lands, and mining. It covers every enactment of Congress from the original ordinance of 1785 to the present time, as well as all sections of the Revised Statutes of the United States relating to these subjects. These laws are grouped according to their general subject matter, and are arranged thereunder in numerical or chronological order. Many of the mining statutes include matter not pertinent to the subject, and only those parts of such acts are quoted as will properly show their relation to minerals and mineral lands and indicate how they should be construed. Some mining acts have been repealed or have become obsolete, and others have become incorporated substantially in sections of the Re- vised Statutes; but these are retained in order to show the changes made, and the constructions placed thereon by the courts are given as aids in construing the new or repealing acts. The annotations consist of legal propositions abstracted from the decisions of the various courts and executive officers of the Govern- ment that have interpreted the sections and statutes so codified. These legal propositions are arranged under the different sections and acts with appropriate headings, titles, and subtitles, in logical order, exhibiting the present status of each particular section or act and its application to the subject of mines and mineral lands. The annotations do not purport to be abstracts of decisions on the sub- stantive law of mines and mining generally, but are limited strictly to the interpretation placed on a given section or act definitely re- ferred to by a court or executive officer by the number of the section of the Revised Statutes or the volume and page of the Statutes at Large in which the Congressional enactment is found. It may be observed that the legal propositions stated are not always pertinent to the particular section or act under which they are classed and of which they purport to give a construction. The arrangement, however, is not an arbitrary one, but is so made for the reason that the courts or officers in the construction of a particular section or act definitely referred to by number or volume and page incorporated in the decision matter not strictly pertinent to the par- ticular section or act so designated. This statement applies especially to the interpretations placed on the sections of the Revised Statutes. The decisions abstracted for the purpose of this work are those of the United States Supreme Court, 234 volumes; the various Federal courts, 214 volumes; the decisions of the Department of the Interior

Jan 1, 1915

By Robert T. Davis

An award is a form of recognition given for superior performance in a special field of endeavor. Each year awards are given by the Joseph A. Holmes Safety Association and the National Safety Council to the coal-mining industry's underground and open-pit mines that have worked a specific number of man-hours without a lost-time injury. These awards have a dual significance in that they prove efficiency can be attained without injury to persons. Safety awards do not result from luck or good fortune but do result from sincere desire coupled with sufficient effort and cooperation to achieve a desired goal.

Jan 1, 1964

By D. Harrington

Although the explosion-fatality record for the fiscal year 1944 showed considerable improvement over those of the preceding 4 years, it is still fur from creditable, and the coal-mining industry and agencies interested in the prevention of coal-mine accidents should not be satisfied until accidents from explosions and fires are eliminated. In view of present knowledge of the methods of preventing explosions and fires, such disasters are inexcusable and discredit the mining industry. Despite this knowledge, far too many coal¬mine operators and employees continue to follow procedures that have resulted in disasters in the past. Included in the appendix to this circular are a number of safety measures designed to prevent coal-mine explosions and fires and metal-mine fires. Their adoption is essential if explosions and fires are to be prevented, as certainly they should be. An epidemic of disastrous mine fires of electrical origin during the past 2 years emphasizes the need for better methods of protection of underground electrical circuits. At present, committees of mining-electrical engineers, electrical-equipment manufacturers' representatives, and others are cooperating with the Bureau of Mines seeking means to solve this problem.

Jan 1, 1945

By Marlion T. McQuinn

This paper will discuss the design, construction, and performance of the support of excavation on the Dulles East and West Automated People Mover Tunnels and Station projects. The elements of the system included drilled soil nails and rock anchors with reinforced shotcrete to the excavated face. We will discuss the geotechnical characteristics, design and construction considerations, loading criteria, construction techniques, schedule constraints, and performance of the support of excavation system. In consideration of the conference theme, there will be a discussion of the application of the real-time instrumentation monitoring program. The project team worked to design and install approximately 710,000 square feet of shotcrete and 19,000 soil nails/rock anchors as well as excavate over 720,000 cubic yards of rock materials within 15 months and in such a manner as to minimize the disruption to airport passengers and operations.

Jan 1, 2006

By Keith D. Rosbury

The basic objective of this project was to determine the cost-effectiveness of dust control used on unpaved mine haul roads. Field testing was conducted at three surface coal mines (two in Wyoming, one in southern Illinois) for a total of 20 weeks. The highest control efficiency measured for a chemical dust suppressant, 82 percent, was for calcium chloride two weeks after application. Generally, however, the control efficiencies hovered in the 40 to 60 percent range over the first two weeks since application, and then decreased with time. After the fifth week, the limited number of data points suggest a control efficiency of less than 20 percent. Composite watering data were fairly uniform. Watering once per hour resulted in a TSP control efficiency of approximately 40 percent. Doubling that application rate increased the control effectiveness by about 15 percent to 55 percent. Chemical dust suppressants (primarily salts and lignons) can be shown to be more cost-effective than watering under some conditions. Data summaries and the analysis of data are contained in Volume I. Volume II contains basic data.

Jan 1, 1983

By A. C. Fieldner

This report is the fourth of a series of annual summaries of research and technologic work on coal by the Technologic Branch of the Bureau of Mines. The coal research program of the Bureau has been broadened and made more flexible to adapt it to changing conditions and needs of the coal industry, and as a result information as to the properties and composition of coal has been increased and new and improved practices in mining, preparation, and utilization of coal have been devised. The present

Jan 1, 1940

By Terry J. Close

At the request of the Idaho Congressional Delegation, the U.S. Bureau of Mines Western Field Operations Center investigated the mineral resources of the 140,000-acre Red Mountain roadless area, located northeast of Lowman, in central Idaho. The area includes U.S. Forest Service Red Mountain RARE II area (4-063). The highly mineralized road less area is underlain mainly by granitic rocks which are transected by a northeast-trending fault system. Associated with the granitic rocks and fault system are gold and black sand mineral resources. At least 1,395 ounces of gold and 858 ounces of silver have been recovered from six lode and placer mines within the roadless area. A total of 525 tons of columbium-tantalum, 2,049 tons of euxenite, 83.5 tons of columbite, and 54,862 tons of ilmenite concentrates have been produced from a nearby black sand mineral placer. Mine workings and facilities in the roadless area consist of two dismantled mills, 15 open and caved underground excavations totaling about 2,900 ft of workings, seven large pits and quarries, over 166 smaller dozer-and hand-dug prospect pits and trenches, and in excess of 66 drill holes. The mineralized sites in the roadless area are covered by about 690 current (1992) mining claims. About 130 individuals are holding the claims. Also within the roadless area are four patented lode mining claims. Twenty-five of the 54 mineralized sites identified during the study of the roadless area have, or likely have, mineral resources. One has gold and three have black sand mineral resources that are marginal or subeconomic. There also are two hot springs with thermal water resources, some veins that could be sources of decorative quartz, and dimension stone which was quarried in the past and could be again.

Jan 1, 1993

By Ruilin Yang

Blast vibration in the highwall from a cast blast in open pit mines or in the hanging walls from a stope blast in underground mines is a common concern. Vibration in such cases is a typical near-field situation where the distance from a blasthole to a point of interest varies significantly compared to the distance between the blast as a whole and the point of interest. Most existing blast vibration models are designed for far-field vibration using a single seed wave to represent all blastholes within a blast and do not simulate wave shape change over the distance. Using the site parameters from the analysis of signature hole vibrations, the present blast vibration model yields reasonable agreement with field measurements in terms of vibration amplitude and frequency. Case studies show that the model has been used successfully to assist field vibration control.

Jan 1, 2010

Jan 1, 1989

By H G. Bosmare, G Bedser, C V. B Cunningham

Peak Quany has achieved substantial improvements to its bottom lie by giving close attention to blasting practice, and in pr@icnlar by introducing electronic delay detonators for routine production blasting. The precision and flexibility provided by these units has enabled the quarry to gain control over fmes and curtail oversize without increasing explosive usage. In addition, the extent of nuisance from blasting vibrations has been reduced.

Jan 1, 1998

By Serhan Guner, Sundar Chiluwal

Although significant research has been conducted on helical piles, there is a lack of research and official design provisions on the helical pile-to-pile cap connections. These connections may govern the global response of pile cap systems—especially in tall and light structures where uplift forces dominate the response. To improve future industry practice, the objective of this study is to understand the influence of pile-to-pile cap connections on the global behavior of concrete pile caps and develop recommendations for their efficient design. For this purpose, 108 high- fidelity nonlinear finite element simulations are conducted to quantify the influences of bracket type, embedment depths, longitudinal reinforcement percentages, shear span-to-depth ratios, and loading conditions on the load, deformation, cracking, and failure behavior of concrete pile caps. The results indicate that the design configurations involving single bracket type may result in premature concrete cracking around the anchorage zones with a 25% reduction in the uplift load capacity. The investigations also confirm that high reinforcement percentages and low shear span-to-depth ratios result in higher load resistance in all bracket types, and that the load capacities of the double and studded bracket types are similar. For applications requiring the use of lower embedment depths, it is recommended that either double or studded bracket types be used. The research findings have applicability to both helical and micro piles given that both include similar connection types. INTRODUCTION Tall and light structures may experience significant uplift forces at their foundations due to large overturning moments from wind or other lateral loads. Helical piles (e.g., Fig. 1a) can provide a cost- effective, practical, and resilient solution for resisting significant uplift forces. In order to realize the full potential of helical piles, it is imperative that the helical pile-to-pile cap connections (see Figs. 1b, c and d for examples) are properly designed to resist the applied forces. However, there is a lack of research and associated knowledge on the influence of pile-to-pile cap connection detailing on the global response of pile caps.

Jan 1, 2019

By W. M. Pytel

The applicability of the beam theory in analysis of roof- pillar-weak floor interaction in partial extraction room-and-pillar mining is presented. The mine structure is modeled as an equivalent multi-indeterminate overburden elastic beam supported by elasto-plastic pillars; resting on a viscoelastic layer of immediate weak floor strata underlain by a competent rock mass. The developed analytical model was initially utilized to conduct sensitivity analyses of different variables affecting the mining system, such as the deformability of coal and weak floor strata, thickness of weak floor strata, number of pillars in a panel, width of pillars, width of panel etc. These analyses were then extended to three overburden strata - coal pillar - floor strata lithologies typical of active coal mining areas in Illinois.

Jan 1, 1989

By J. H. East, D. Harrington

"INTRODUCTION Shaft mines, coal and noncoal alike, have a common hoisting problem that remains largely unsolved - how to obtain a mechanical device that will suspend a cage or skip in a mine shaft if the hoisting rope should break or become detached from the cage or skip and that will function effectively under all conditions of service. Safety catches, or safety dogs, as they are commonly named, are installed on nearly all mine cages and many skips operating in American mines, but often, if the hoisting rope breaks, the cage or skip falls to the bottom of the shaft in spite of safety devices, causing much property damage and often fatalities.Available information relative to safety catches for mine cages and skips, desirable characteristics of safety catches and methods of testing safety catches to determine whether they are functioning correctly has been assembled in this publication for the convenience of those responsible for the safe operation of mine cages end skips and, more particularly, to focus attention on the need for a device that actually will stop and suspend a falling cage or skip under all conditions of use and do it without killing or maiming the occupants."

Feb 1, 1948

By Mohan K. Wali

Soil and vegetation development were studied on abandoned mine sites near Velva in Ward County, North Dakota. The sites studied were 1, 7, 17, 30 and 45 years old since abandonment; unmined sites were also studied to provide measures of comparison. Species diversity was the highest at unmined sites (114) and lowest at the I year old site (26); sites 7, 17,30 and 45 years old had 37, 52, 43 and 68 species, respectively. Stand ordination revealed that site ages were the most important in influencing species diversity and composition. Stand-environ-mental complex ordinations encompassing 53 variables showed topographic variables to be the most important followed by site ages. Rates of nutrient accumulations were as follows: organic carbon 13.1 g m-2 yr-1; nitrogen 2.5 g m-2 yr-1; phosphorus 0.01 g m-2 yr-1; potassium 0.49 g m-2 yr-1. Carbon-nitrogen ratios showed the widest range for 1 year old sites (5-40) but 70 percent of the 45 year old sites showed values below 15 which were com-parable to the unmined mixed grass prairie sites. Species distributional diagrams are provided to show their habitat preferences which may be helpful in formulating species prescriptions for revegetation.

Jan 1, 1982

By W. E. Coates

The social ecology of surface mining in urban areas is illustrated by a case study of a recent application for the opening of a new gravel pit in the city of Guelph, including the design of a progressive extraction-rehabilitation sequence for the property, investigation of the ecological impact of the proposed operation, history of the application procedure for a zoning change and the relationship of the operating plan to provincial legislation controlling surface mining.

Jan 1, 1972

By T. Egleston

The materials containing copper which are refined in the United Statrs, are, for the most part, the natiye noppers of Lake Superior. IJntil quite recently but little pig copper Was made for sale, and that came principally from the pure sulphorous ores of New England and the Sonth, and was generally sdd to reSneries not far from the ore filrnaceu. A stnall aiuoiint found its way into the'niarket which was produced either as the by-product of the treatment of gold and silver ores, or as the result of the treatment of impure copper ores; but both these grades, on account of the impurities they contained, were loolced on with stlspicion, and were not sought for. A11 the grtlGis of pig coppcr are sold by the unit of oopper contents, a great redtiction being made in the price when impurities are present. There are at the present time only three works which treat native copper, the two of the Detroit and Lake Superior copper Company, and the works of C:G. Hussey & Co., in Pittsburgh. There are a few works ivhich smelt sulphuroris ores and refine their pig; bo sides these t1le1-e arc a few siuall works where gig copper is refined uuly. Some of these purcIlase blscir copper, refine scrap, or simply refine such grades of ingot copper as are found in the market, but nlostly that from Lake Superior, for the purpose of getting it into swh shapes that can be handled cpmtriercially to advantage, such as in making large plates or high grades of wire fir electrical purposes. A nomher of such works are situated in the Xaugaturk Vatley aud elsewhcre in New England. The recent discoveryof vnlt~sblc ores in Ariarona makm it probable that within a few year8 the refining of capper In the United States will make great develupments. Up to the time of the discovery of the mines on Lake Superior, only a very small quantity of native copper had ever been foond, not sufficient to justify the erection of worlrs fbr its special treatment. It had, besides, never been found in very large maweq so that the discovery of greabblocks of it presented serious difficulties, not oolp in mining it,-I- but in bringing it into a merchantable condit'ion. It seemed a very simple process to melt these large maws,

Jan 1, 1881

This Bureau of Mines report and its companion report (Information Circular 9143) have been prepared to assist in the preparation of prefeasibility type estimates for capital and operating costs of mining of various types of mineral occurrences using current technology. The handbook provides a convenient costing procedure based on the summation of the casts for the unit processes required in any particular mining or mineral processing operation. The costing handbook consists of a series of costing sections, each corresponding to a specific mining unit process. Contained within each section is the methodology to estimate either the capital or operating cost for that unit process. The unit process sections may be used to generate, in January 1984 dollars, costs through the use of either costing curves or formulae representing the prevailing technology. Coverage for surface mining includes dredging, quarrying, strip mining, and open pit mining. The underground mining includes individual development sections for drifting, raising, shaft sinking, stope development, various mining methods, underground mine haulage, general plant, and underground mine administrative cost. This system can be used for estimating cost data for an undeveloped deposit or for checking or verifying mining costs from a developed deposit, with a minimum amount of background information.

Jan 1, 1987

TO THE. BOARD OF DIRECTORS AND MEMBERS OF THE AMERICAN INSTITUTE OF MINING AND METALLURGICAL ENGINEERS GENTLEMEN Submitted herewith are the report of the Treasurer for the year 1945 and reports for the same year of the following committees: Membership, Admissions, Papers and Publications, Mining and Metallury (Magazine), and Library. In this review of the year by the Secretary reference frequently will be made to the "Paul" Committee and to the "hotter" Committee. The first is the special committee on Divisional Relationships and the second the special Committee on Ways and Means. These two important committees, appointed by President Harvey S. Mudd under authorization of the Board of Directors on March 21, 1945, were composed as follows:

Jan 1, 1946