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By Joan Weinberg

Seasonally adjusted new factory orders for primary metals declined in January, February, and March, especially in the steel industry. The decline was part of an apparent slowdown for the entire manufacturing sector. Orders for all durable goods, including not only primary metals, but also clay, glass, and stone products, fabricated metal products, machinery, and transportation equipment, fell in January and February. In March, orders rose a slight 0.8%. According to the U.S. Department of Commerce, the downturns in durable goods orders in January and February were the first back-to-back declines in 3 years. They were largely attributed to a drop in orders for transportation equipment, mainly auto-mobiles and aircraft, while the small gain in March was due to a surge in aircraft orders. Higher interest rates may be partly responsible for the slowdown in durable goods orders over the past 3 months. The higher rates have also hit the construction industry--another major end-user of minerals. Construction of new homes and apartments fell by a seasonally adjusted annual rate of 5.4% in March, following a 12% decline in February.

Jan 1, 1989

The National Economic Viewpoint? Any substantial project undertaken by private enterprise would normally be subjected to a Discounted Cash Flow analysis of its commercial viability, and would proceed only if the rate of return was judged satisfactory. A 'national viewpoint' analysis attempts to do the same but from the viewpoint of the community as a whole. The objective is to ensure that those projects are undertaken which yield the best return, economic and social, to the nation as a whole.

Jan 1, 1984

By John E. Trombly

System objectives and design criteria for an in-mine visual personnel paging system are discussed. Display technologies are evaluated and tradeoffs leading to display selection are described. The prototype dispatcher's console, battery/receiver box and visual display assemblies are functionally described. The report includes circuit descriptions, schematics, parts lists and equipment cabinet drawings for the three assemblies. The report concludes with an estimate of the manufacturing cost for each assembly.

Jan 1, 1975

By K. K. Kelley

This work is both a revision and an elaboration of Bureau of Mines Bulletin 371, which was published in 1934 and included data available to October 1933. During the intervening years, a large number of new experimental, high-temperature, heat-content data have become available through continuous, systematic efforts of the Pacific Experiment Station of the Bureau of Mines and the Laboratory for Inorganic and Physical Chemistry of the University of Groningen (Netherlands), coupled with various individual investigations at many institutions. In addition, calculations from spectroscopic and molecular constant data have been extended and applied to a wide variety of gaseous substances. This bulletin purposes to collect and correlate all available high-temperature heat-content and specific-heat data for inorganic sub-stances and to formulate tables and algebraic expressions for their representation. It is hoped in this manner to remove some of the tedium of thermodynamic calculations for industrial metallurgical research workers and engineers who often have available only an inadequate library in this field. It is expected also that this bulletin will have value to those teaching courses in metallurgical and chemical thermodynamics.

Jan 1, 1949

By Liming Yuan, Isaac Zlochower, RICHARD THOMAS, Thomas H. Dubaniewicz, Teresa Barone

Mining vehicle manufacturers are developing lithium-ion (Li-ion) battery electric vehicles as an alternative to diesel-powered vehicles. In gassy underground mines, explosion-proof (XP) enclosures are commonly used to enclose electrical ignition sources to prevent propagation of an internal methane (CH4) air explosion to a surrounding explosive atmosphere. Li-ion batteries can create pressurized explosions within sealed enclosures due to thermal runaway (TR). Researchers at the National Institute for Occupational Safety and Health (NIOSH) measured TR pressures of lithiumiron phosphate (LFP) cells as a function of free space within sealed enclosures and observed an inverse power relationship. A well-confined cell produced 294 bar (4260 psia) of pressure during a TR, far exceeding minimum pressure containment specifications for conventional XP enclosures. Results indicate that adding enough free space surrounding LFP cells can reduce TR pressures to levels below that expected for CH4-air ignitions. Measured TR temperatures were below the minimum autoignition temperature of CH4-air.

Nov 6, 2020

By Ellis S. Hertzog

The data published in this retort cover only one phase of a special study of tile physical and chemical properties s of only Alabama coals made by the Bureau of Mines. In addition to determinations of friability, the survey included determinations of grindability, B.t.u. value, and ash-fusion temperature. Assay distillation tests, both for high- and low-temperature carbonization, and proximate and ultimate analyses were made also. However, this preliminary paper is concerned only with the results of friability tests and is issued to expedite the release of this information to the public. The friability, test measures the liability of a coal to break into smaller pieces when subjected to repeated handling, as occurs in the mining, preparation, and transportation operations. Friability depends on many physical characteristics of the coal that vary not only between different seams but also in the same seam. The laboratory methods of determining friability have been developed to give a practical means of estimating degradation of size. So far as is known to the authors, no data on the friability of Alabama coals have ever been published. This caper makes available for the first time fairly comprehensive3 information on this subject. Because the procedure for the tumbler test for determining the friability of coal is relatively new to the coal operators, the authors Lave included a, complete description of it in this report.

Jan 1, 1938

By Chu E. Ho, Paul Napoli

This paper presents the performance of nineteen open-ended steel pipe piles driven through highly variable overburden soils into glacial till and schist bedrock. The piles were 16 inches in diameter and 0.656 inches thick, with yield strength of 50 ksi. The piles were designed for a service capacity of 250 kips and were driven to achieve an ultimate geotechnical capacity of at least 500 kips. Due to the large variation in the ground conditions, installed pile lengths ranged from 25 to 66 feet. Some piles were driven to refusal on the bedrock while others were terminated at final driving resistance of 2 to 7 blows/in. Two piles were suspected to be plugged during driving while others did not. Each pile was instrumented with strain gages and accelerometers near the pile top, and observed using a Pile Driving Analyzer (PDA) to provide preliminary guidance on pile capacity achieved at end of initial drive (EOID). The influence of plugged and unplugged pile toe conditions on the interpretation of pile capacity was investigated using Case Pile Wave Analysis Program (CAPWAP). Characteristics of driving energy, compressive and tensile stresses developed in the steel pipe piles, and the resulting pile deformation behavior are discussed. INTRODUCTION The Hunters Point South redevelopment in Long Island City, Queens is one of New York City’s major efforts to transform former manufacturing zones into mixed developments for the middle-income community. The site is located along the eastern shoreline of the East River and Newtown Creek. The development included low to high-rise residential buildings, a public school and retail structures. Open spaces were created along the East River and Newtown Creek waterfronts in the form of a continuous park providing for recreational and community related activities. Waterfront structures included small park buildings, walkways and viewing platforms with the shoreline protected by revetments as part of the City’s flood mitigation strategy. The project was implemented in two phases, with completion of construction for Phase 1 in 2013 and Phase 2 in 2019. Based on available historical information, extensive reclamation took place between 1855 and 1898. After 1951, changes to the shoreline were made along the East River, including the removal of reclaimed land along the northern portion of the project site to allow for docking facilities. By 1977, these facilities had been demolished and backfilled to form the current shoreline configuration. The present site was temporarily used as a parking lot with stockpiles of fill mixed with construction demolition rubble, rip-rap and boulders of varying heights across the site. The existing ground surface varied significantly up to approximately 25 feet difference in elevation. The stockpiles were removed and the site was re-graded during final development of the project. This paper discusses the foundation design challenges due to the loose overburden soils and potential obstructions within the fill material, in particular, the issues relating to installation of open-ended steel pipe piles through the ground conditions encountered on site.

Jan 1, 2019

By João Paulo Ferreira Santos

Neste trabalho foram obtidos nanocompósitos híbridos constituídos por nanotubos de carbono de paredes múltiplas (MWCNT) e por nanofibras eletrofiadas de nylon 6 em uma matriz epoxídica. Os MWCNT foram funcionalizados com grupamentos carboxílicos e dispersos através de ultrassom na resina epoxídica. A composição resultante foi disposta de maneira alternada com mantas de nanofibras de nylon 6 para formar estruturas compósitas na forma de sanduiches, as quais foram termicamente curadas. Medidas de resistividade elétrica das estruturas obtidas mostraram que uma percolação elétrica entre 0,05% e 0,5% (v/v) de MWCNT foi alcançada. Do ponto de vista mecânico, a incorporação de MWCNT na matriz epoxídica resultou em aumentos de módulo de elasticidade (26%) e na resistência a ruptura (19%), porém, devido a presença de aglomerados de nanocargas, a deformação na ruptura e a resistência ao impacto foram severamente reduzidas para 71% e 33%, respectivamente. Por outro lado, a adição de nanofibras de nylon 6 para formar um híbrido, mostrou-se, bastante promissora ao levar a aumentos de 8% na resistência ao impacto sem ocasionar perdas de módulo elástico, na resistência à ruptura e na deformação na ruptura.

Aug 8, 2018

By Philip B. Grote

The deep ocean mining industry is in a pre-commercialization stage of development. In the context of a proper legal/regulatory regime, deep ocean mining system design, site survey, and operation technologies are capable of rapid evolution. The report recommends that the regulatory framework develop in parallel with the industry and presents a rationale for implementing this approach. The Government has several interests in deep ocean mining technology: (1) as a potential regulator, sound regulations should be based on an understanding of the technology; (2) as a potential monitor, survey technologies are relevant; and (3) as an estimator of strategic minerals supplies, it is important to understand the technology which allows economic access to deep ocean minerals. Thus, the major portion of the report presents an in-depth review of systems design, operations, and survey equipment and techniques.

Jan 1, 1979

By L. G. Marshall

Gypsum mining and processing has been one of the principal industries in Iowa for more than 75 years. For most of that period, Iowa has ranked among the five leading States in the production of crude gypsum and of calcined-gypsum products. The Fort Dodge area accounted for 11 percent of the gypsum products produced in the United States in 1956. Before 1927 the output by the major companies came from underground operations, using a room-and-pillar stoping method. At present, all production comes from quarries. The quarry methods at the various properties are similar. This paper describes the quarrying, methods employed in the district and the type of equipment used by each company. The sections on history and geology are, in part abstracts from State annual reports and an Iowa Geological Survey publication.3/

Jan 1, 1959

By Yongjun Xian

The release of fluid inclusions has a strong potential for the unintentional activation of pyrite during flotation. The present study aims to characterize fluid inclusions in a natural pure pyrite. The results indicate that a certain amount of fluid inclusions exist in the pyrite. The fluid inclusions assume a variety of shapes, including long strips, oval shapes and irregular shapes, with sizes that range from a few microns to dozens of microns. From the EDS results of hollow positions that resulted from the fracture of the fluid inclusions on the pyrite surface, certain amounts of Al, Cr, C, O, Ag and Cu were clearly detected; these elements were not detected in FeS2 pyrite itself. The contents of the inclusions were released into solution when the sample was subjected to a grinding process. Under experimental conditions of 2 g of pyrite cleaned in 40 mL of pure deionized water under an inert atmosphere, the concentrations of Cu, Fe, Cl- and SO4 2- released from the inclusions reached concentrations of 3.29 × 10-6, 32.52 × 10-6, 51.57 × 10-6 and 75.90 × 10-6 mol/L, respectively. These values are significantly greater than those from the experimental nonoxidative and oxidative dissolution of the pyrite. The fluid inclusions of pyrite were, therefore, concluded to represent the dominant sources of Cu, Fe, Cl- and SO4 2- in the aqueous solution. The present investigation provides a new understanding of the source of the unavoidable metal ions in the pulp and may benefit understanding of the flotation theory and environmental geochemistry.

By Gordon Sproule

THE papers presented to the Institute, and published in the BULLETIN, in the past three years, may be classified as follows: Geology, Mining, and Milling 89 or 58.5 per cent Smelting, Refining, and Refractories 17 " 11.2 " Mechanical and Physical Metallurgy 7 " 4.6 " General (Economics, Welfare, etc.) 39 " 25.7 " Total 152 100 These figure~ should be excuse enou.gh for. the present paper. As indicated by the title it is proposed: I.-To review briefly some of the more recent developments of Physical Metallurgy; and 11.-To show how Physical Metallurgy functions as the link between mining and production metallurgy on the one hand, and consumption engineering on the other hand. Io these days of specialization, papers of the kind being considered mostly gravitate to the American Society for Metals, the American Society for Testing Materials, the Institute of Metals, and the Iron and Steel Institute. In proof that there is a place for the newest and most specialized of these societies, the American Society for Metals, it may be said that in the Montreal Chapter there are 200 active members, and in the Ontario Chapter more than 200. Yet the overshadowing glamour of the mining industry proper, and the publicity it receives, result in an almost continuous dearth of students in metallurgical engineering at our universities. There are more jobs than graduates.

Jan 1, 1936

The growth and influence of Sherritt Gordon Mines Ltd. in the nickel producing industry has been quite phenomenal. Although the company's Lynn Lake deposit in Manitoba was actually dis- covered in 1941, it was not until 1945, when men and materials were more readily available as a result of the end of World War II, that the area was staked and news of the discovery leaked out. As a result of the discovery, Professor Frank Forward of the University of British Columbia was commissioned by Eldon Brown, then President and Man- aging Director of Sherritt, to develop a new nickel refining process. A pilot plant, based on the results of Professor Forward's research, was constructed in Ottawa, and after the successful testing of the Lynn Lake ore, Chemical Construction Co. was given a con- tract in 1952 for construction of a producing plant. By 1954, the Fort Saskatchewan refinery was operating at an annual production of 15 million lb of nickel metal in the form of briquetts or powder. Capacity has since been increased to 30 million lb.

Jan 10, 1968

By J. Y. Murdoch

TAXATION has become a major item in the operation of Canadian mines, and, as such, merits our most serious consideration. I feel it was a splendid idea for the Institute to set aside this time for a frank discussion of this important subject, and believe great benefit will result from a better understanding of the methods and underlying principles involved. Mining, as a great national industry, may quite properly be called upon to pay its fair share of the cost of running the country; and there is no tendency on our part to avoid this responsibility. There is, however, a very definite demand that the proportion be just, and fairly and sensibly applied. I believe that Mr. C. G. Williams, Secretary of the Canadian Metal Mining Association, and others, are giving details of the various Provincial and Dominion regulati6ns, so I shall not touch on that phase of the situation. However, there are some important factors to which I should like very briefly to call your attention. The first is the vital need for stability. As you all know, a considerable period must elapse between the preliminary stages of any mining venture and the time when it comes to production-or is finally abandoned as un-profitable. These early days are fraught with many unavoidable uncertainties. If, to these natural hazards, the apprehension of instability of governmental action be added, the risk becomes so great that capital seeks other and safer fields for investment, and many otherwise promising projects are thus discarded. There probably never has been a time in recent years when so much money was seeking investment as now. Under favourable conditions, the development of our great mineral resources would be a natural and attractive outlet for this money. The amount of taxation which the mining industry can properly absorb is of the utmost importance at this time, and it might be well to consider this question in its relation to the economic stability of our country, for it cannot be too greatly emphasized that direct taxation is only one item in the net return which our governments derive from the mining industry. Indeed, the many indirect benefits are so manifest that it would seem almost unnecessary to enumerate them! We almost invariably think of mine taxation as a direct company tax-overlooking the fact that sales tax, customs duties, acreage tax, income tax on mine dividends, foreign shareholders' dividend tax, and others, must all be taken into consideration. It would seem that the economic value of non-ferrous metal mining in Canada is not sufficiently understood and appreciated.

Jan 1, 1935

By Edward L. McHugh

The study area, which comprises 28,443 acres within the Jacumba Wilderness Study Area, is in the California Desert Conservation Area, and along the U.S.-Mexico border 25 miles west of Fl Centro, CA. The U.S. Bureau of Mines evaluation of mineral resources is based on examination of mining claims, known mineral occurrences, and mineralized zones during the fall of 1983. Limestone resources were identified inside the study area; tungsten resources may he present. Metasedimentary rocks intruded by Cretaceous Quartz diorite predominate in the study area. Tungsten and some gold have been found in skarn zones along intrusive contacts; limestone deposits are in the pre-Cretaceous rocks. Tertiary and Quaternary volcanic flows, pyroclastic rocks, clay beds, and diatomite in lake deposits nave been investigated for possible non-metallic resources. Evidence of mining or prospecting was found at 26 sites in or just outside the study area. In 1983, 106 claims were held in 13 claim groups. One claimant was sporadically prospecting for gold on claims in the north part of the study area in 1983, and gravel was being mined from alluvium 1/4 mile to the east.

Jan 1, 1985

By Michael Mancuso

This report summarizes the problems of topsail handling as related to present requirements of law and current equipment availability. The most prevalent topsoiling systems are reviewed along with a listing of advantages/disadvantages and best features of each system. Seven mining regions are included, along with an analysis of prevailing land use, types of soils and attendant physical, chemical am biological characteristics. There are several probable areas of future research "lined which can benefit mining, minimize the social impact of mined lands and speed the return of mined lands to more productive long-term use.

Jan 1, 1981

By Furuyama Takashi, Mori Sukeyuki, Hara Tsuyoshi, Fukushima Yujin

In mineral processing practice, flocculation is largely established as an engineering technique of waste water treatment and the study of parameters increasing the settling velocity of particles is still of great importance to improve the process. Further investigations were made using quartz (Q89) and fluorite samples (F91) which included 58.8% and 65.8% of -2.3 µm particles respectively. In all the experiments the flocculation phenomena were observed varying the pH value of the aqueous suspension. In contrast to quartz particles (Q89) which did not flocculate for all pH values, it was, noticed that fluorite particles (F91) flocculated in the alkaline range of pH over 11. With an aqueous suspension containing equal quantities of Q89 and F91, a hetero-flocculation of particles was observed at a range of pH below 10. In this case, the maximum floc size of the hetero-flocculation was 37.0-26.2 µm This size was about three times larger than when quartz (Q84) and fluorite particles (F85) were used with 32.4% and 40.4% of -2.31 µm particles respectively. Besides, in the experiments using Q89 and F91, the maximum size of hetero-flocculated single particles was found to be 6.54 µm instead of 3.27 µm as obtained with Q84 and F85.

Jan 1, 1995

By L. A. Morley

Volume IV of the final report examines the problem of indirect contact of overhead high-voltage power lines by mining personnel. This refers to the contact of energized lines by workers through some intermediate conductor such as a metallic tool or a piece of high-reaching mobile equipment, thus the term "indirect contact." The shock hazard presented by such contact has been a major cause of electrical fatalities associated with mining operations. The report volume is divided into three major areas. The first gives a general background of overhead lines, basic characteristics, and associated hazards, and continues to describe presently used techniques and devices which attempt to alleviate the contact problem. The second area narrows the discussion to the mining industry by presenting a detailed analysis of 39 overhead-line contact accidents in mining since 1970. The third major section uses the information from the first two areas to formulate recommendations to prevent these accidents and subsequent electrocutions at mining operations.

Jan 1, 1982

By W. L. Dare

This information circular is one of a series the Bureau of Mines plans to publish describing the methods and costs of mining uranium on the Colorado Plateau. The Big Buck mine is one of the larger underground uranium-vanadium ore mines on the plateau. The mine is about 39 miles southeast of Moab in the Big Indian mining district, San Juan County, Utah. The Big Buck claims were located late in 1947, when uranium mineralization was discovered in the Cutler formation at its outcrop along the escarpment that forms the west side of Big Indian Wash. Charles A. Steen made the first major discovery of uranium ore in the Chinle formation in the Big Indian mining district on July 6, 1952, when 14 feet of high-grade uranium ore was encountered in a diamond-drill hole drilled on his Mi Vida claim. The Big Buck ore body now being mined by Standard Uranium Corp. is a southeast extension of Steen's original discovery.

Jan 1, 1956

By G. S. Rice, H. P. Greenwald, H. C. Howarth

"""Rock-dust barriers""5 as they are termed in this country, are for the purpose of confining a coal-dust mine explosion to the limited area in which it originates. These barriers were first tested in 1910-1911, with favorable results under the conditions of test, at the French official gallery which was then at Lieven, Department of Pas-de-Calais. Shortly afterwards the Bureau of Mines in the course of its investigation of all practical explosion-prevention methods tried barriers in the Experimental Mine near Bruceton, using the primary form of simple fixed cross shelves 20 inches wide extending over the passageway and laden with rock-dust. The Bureau termed them “Taffanel barriers"" in honor of the director of the Lieven testing station. The trials were made in conjunction with tests of explosibility of different coal-dusts.Experience showed that although the principle of barriers had merit when they were used for secondary defence, the primary form was uncertain in effectiveness. This led the senior author to design mechanically discharging barriers to be operated by the compression air waves which precede the flame of an explosion. For the better understanding of the principal involved, it is pointed out that the advance air waves are what make a coal-dust explosion possible by stirring up the coal-dust from the walls and floor of the passageway. If a barrier can throw inert dust into the air to form a cloud as dense or denser than that formed by the coal-dust, it will neutralize the explosiveness of the coal-dust, and the flame of the explosion will be extinguished. When the flame ceases, the pressure dies away in a short distance if the 'area that had been traversed by the explosion is not large."

Jan 1, 1930