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By Alexander L. Peyton

The Magruder and Chambers copper deposits in the Little River gold district, on the border line of Lincoln and Wilkes Counties, Georgia, have been known for a number of years (fig. 1). The Magruder deposit was first opened as a gold mine but has produced mostly copper and load. Records show that about 50 cars of concentrates were shipped from this property. No record of any production at the Chambers deposit is available. The Bureau of Mines, in its program of investigation of strategic minerals deposits, diamond drilled 10 holes, totaling 3,784 feet, on the two properties between December 3, 1948, and June 23, 1949. Eighty-eight core samples were analyzed, and the analyses and drill-hole data are presented in this report.

Jan 1, 1950

By A. W. Deurbrouck

This report presents the results of a washability study of 322 coal mine samples showing the sulfur forms and distribution in the coals. The samples were collected from mines which were principally utility coal producers. Generally, the data show the total sulfur content of the coals evaluated could be significantly reduced by some combination of stage crushing and specific gravity separation. However, few coals could be upgraded to a final product containing 1 percent or less total sulfur. The complete washability data are presented for each sample processed. A statistical evaluation is included for the coalbeds from which more than 10 samples were collected and for the geographical coal producing regions. A graphical summation is presented for the coal producing regions and selected coalbeds.

Jan 1, 1972

By William J. Wuest

The technical analysis of parameters that can influence roof and rib reinforcement is important to the operation of safe and profitable underground mines. One such parameter, studied in this U.S. Bureau of Mines investigation, is the effect of time on untensioned, resin-grouted bolt anchorage characteristics. A group of seventy-three 4-ft-long bolts with three different grout column lengths were I installed in a stable coal mine roof. The bolts were then subjected to standardized pull tests at various intervals throughout a 37-month period. For each test, load-deformation data were reduced to determine axial stiffness and yield point. The magnitudes of these two anchorage characteristics at the time of installation were compared with results from subsequent pull tests to determine if anchorage capacity deteriorated. Bolts with 18-in grout columns were studied over 9 months, and no measurable loss occurred. Bolts with 48-and 24-in grout columns were studied over 37 months and also exhibited no measurable loss.

Jan 1, 2010

By Ren G. Dong, Kristine M. Krajnak, Dan Welcome

Continual occupational exposure to vibrating hand tools can damage the neural, vascular and other soft tissues of the fingers. Rat tail models have been developed to investigate the biological responses of the tissues to vibration.1-2 However, the biodynamic response of the tail relative to that of the human fingers has not been characterized. The objective of this pilot study was to compare the transmissibilities of rat tails measured via a scanning laser vibrometer to those of human fingers gripping a handle. Methods In Part I of this experiment, four male Sprague Dawley rats (6 weeks old) were exposed to discrete 5g-rms sinusoids of 32, 63, 125, 160, 250, and 500 Hz. The rats were restrained in Broome-style restrainers with their tails constrained without compression to an exposure platform via elastic straps as shown in Figure 1. The platform was attached to a vertically vibrating shaker. The vibration was measured for the array of points shown in Figure 1 using a scanning laser vibrometer (Polytec) and the transmissibility calculated for each point on the tail relative to the reference points on the platform. In Part II, three male human subjects were exposed at the frequencies specified in Part I - with the addition of 1000 Hz - at a magnitude at the ANSI <0.5-hr limit up to 63 Hz, after which the acceleration was held constant at 5g-rms. The subjects gripped an instrumented handle at 20 N as shown in Figure 2. The transmissibility was calculated relative to the reference points on the handle. [ ]

Jan 6, 2006

Since mid-July, most domestic producers have been marketing 99.5 percent unalloyed aluminum ingot at 53-57 cents per pound. Dealers in the United States have recently quoted ingot at 52.3-52.8 cents. On October 2, London Metal Exchange will trade aluminum, selling contracts on a cash and a 3-month basis. New York dealers were quoting August ingot at 52.3 52.8 cents. The Bonneville Power Administration announced that, effective December 20. 1978, electric power rates charged primary aluminum producers in the Pacific Northwest would be increased The increase (equivalent to about 4 cents per pound of aluminum produced) will raise the average rate to about 8.7 mills per kw-hr compared to 3.2 mills per kw-hr.

Jan 1, 1978

By Eugene H. Skinner

The 7-mile Flathead Tunnel, located in the central Salish Mountains of northwestern Montana, was constructed between 1966 and 1969, With the contract awarded April 19, 1966, drill and blast tunnel excavation began September 30, 1966, and was completed June 21, 1968, in 488 tunnel-driving days, Peak advance was 66 feet per day. On June 27, 1969, all tunnel concrete lining was completed. Average wall and arch concrete placing rates exceeded 1,700 cubic yards daily, with nearly half of the concrete placed during a severe winter season. Major cost savings in concrete tunnel lining were achieved through a value engineering clause in the contract. Achieving consistent results and high rates of placement in concrete lining ranked equal to ground control in overall tunnel problems. Ground control problems exceeded expectations and were of continual concern throughout excavation, One support collapse in the tunnel and one portal slide condition developed during construction. Critical surface geologic exposures were largely obscured; only a portion could be accurately projected underground, An instrumentation program to gather basic data on rock defamation near the heading face for support purposes was a pioneering effort. The Flathead Tunnel was placed in service on November 7, 1970.

Jan 1, 1974

This section of Minerals and Materials analyzes the following three factors affecting the recent performance of the U.S. and world mineral industries: 1) the health of the U.S. and world economies, 2) the level of interest rates and 3) the performance of productivity in both the U.S. mineral industry and the general economy. While these indicators do not exhaust the possible critical factors, they represent an initial attempt to probe some of the considerations underlying the performance of the U.S. minerals and materials industry. The U.S. and World Economies It is essential to analyze the state of the U.S. and world economy because the demand for minerals and materials is a derived demand; that is, since minerals and materials are used in the productive process, the demand for them is a direct function of the demand for the finished products of which they are a basic input. Thus, the demand for minerals and materials is directly affected by changes in present and planned consumption and investment expenditures. The past two issues of this publication have highlighted the generally discouraging performance of the national and inter-national economies. Briefly, the world economy is in the third year of the first long recession in recent history where inflation rates have remained above 5 percent. With many countries either unable or unwilling to support domestic spending while inflation continues, there has been a growing tendency to institute trade-restrictive policies to support domestic demand. The resulting weakened demand conditions in exporting nations have had a direct effect on the mineral industry.

Jan 1, 1982

By Pedro Lilienfeld

This report describes a program whose objective was to develop, design, fabricate and laboratory-test two prototype instruments capable of real-time selective detection and measurement of airborne fibrous-shaped particles. The operation of this fibrous aerosol monitor (FAM) is based on the rotation imparted to the acicular particles by means of a rotating quadrupole electric field of the order of 3000 V/cm. This field induces a dipole charge separation on the fibers and aligns them with the applied field. The selective detection of the fibers is effected by synchronous detection of the resulting modulation of the light scattered from a continuous-wave helium-neon laser beam by the rotating particles. The theory of operation, design of the electric-optical detection configuration and the electronic signal processing method are discussed. By means of a scattering pulse sharpness discrimination technique, fibers whose length exceed a selectable value are detected and their number concentration digitally displayed. Counting times of 1 to 1000 minutes permit the measurement of fiber concentrations between 0.001 and about 30 cm-3. A concentration of the order of one fiber per cubic centimeter can be assessed within a relative standard deviation of 10 percent with a counting period of 10 minutes. The FAM is a portable, battery-powered instrument capable of operating continuously for about 4 hours between battery charges. Preliminary tests with crocidolite and crysotile asbestos as well as with glass fibers were performed in the laboratory and the results indicate good correlation with the standard NIOSH phase contrast microscopy filter counting method.

Jan 1, 1977

By C. W. Owings, J. J. Forbes

"Although coal-mine explosions rank third among causes of underground fatalities, they receive more wide-spread attention than any other accidents in mines because frequently many persons lose their lives in a single disaster. Each bituminous coal-mine explosion endangers the lives of approximately 100 persons--the average number employed underground in a commercial mine. A critical analysis of coal-mine explosions in a restricted district gives a cross-section of relative existing explosion hazards, of common causes of ignitions of gas and dust, and of effective prevention measures. The Safety Division of the United States Bureau of Mines is collecting data on coal-mine explosions in the various States, and this circular is one of a series analyzing the causes and recommending methods for thy prevention of similar occurrences,The data on this circular are based on records of the United States Bureau of Mines and the West Virginia Department of Mines. Unfortunately practically all of the early records were destroyed by fire in the State House at Charleston, W. Va.; the remaining records were made available to the authors by N. P. Rhinehart, chief of the Department of Mines, and his cooperation is gratefully acknowledged.The earliest available reference to coal in West Virginia is that made by John Peter Lally who in 1742 found ""a great plenty of coals"" near a river later called Coal River. In 1809, Nicholas Roosevelt found coal along the Ohio River and used it on the New Orleans, said to have been the first steamboat west of the Allegheny Mountains. In 1810, Conrad Cotts opened a mine near Wheeling and sold coal for domestic purpose in 1812, a mine was opened on the Ohio River opposite Mason City and produced 1,200 bushels of coal that year. In 1840 the total West Virginia coal production was 298,691 tons; in 1863, the production had increased to 444,468 tons, and in 1883, to 2,335,833 tons. During this period apparently most of the coal was extracted from coal outcropping on the hillsides; little danger of gas ignition existed at that time, but explosions from blown-out shots occurred frequently. On February 22, 1383 the West Virginia legislature enacted legislation providing for a mine inspector to inspect the mines of that State, to prevent mine accidents, and to insure properly ventilated mines.In a special report to the Governor on December 31, 1884 the Inspector of Mines reported:We have 5 shafts, in 4 of which there is more or less gas; and in 1 of our drift mines there was an explosion on the 27th day of March 1880, whereby 2 men were killed and a boy badly burned.Table 1 lists 287 explosions in West Virginia coal mines. Several early explosions were listed in the annual reports of the West Virginia Department of Mines as ""blown-out shots"" or ""powder explosions"". The injuries usually were described; explosives accidents have been eliminated from these and other available data, and only those in which dust or gas were involved have been included in this paper as explosions."

Sep 1, 1934

By F. G. Miller, H. C. Miller

Petroleum technologists and progressive operators constantly are striving to increase the percentage of oil that may to recovered from reservoir rocks through wells. The exhaustive studies that have been made of the function of natural as in the production of oil, for example, have aided operators greatly in increasing the quantity of oil recovered from reservoirs. Natural gas dissolved in and otherwise associated under pressure with oil in reservoir rocks, however, is not the only source of energy available for moving oil through sands to wells. In becoming "reservoir—energy conscious" engineers have learned that in many petroleum reservoirs the edgewater flanking the oil accumulation constitutes a potential source of energy capable, through proper control, of increasing oil—recovery efficiencies materially. No longer is the encroachment of water into the oil— and gas—filled tart of the reservoir considered as an evil to be combatted by devious methods but rather a natural consequence, incident to the withdrawal of nil and as from the wells, that may be used advantageously in lengthening the flowing life of wells and increasing the economic recovery of oil and gas.

Mar 1, 1938

The Aluminum Company of America (Alcoa) announced that the second unit at its experimental facility at Palestine, Tex. would begin production -in 1979, increasing the capacity of the facility to 30,000 tons per year. The plant uses an experimental process based on the electrolysis of aluminum chloride and reportedly uses 4 to 5 kilowatt hours per pound of aluminum produced, compared to an industry average of about 7 to 8 kilowatt hours per pound. Alcoa has reportedly signed a letter of intent with the Chinese government under which Alcoa will conduct feasibility studies on two new integrated aluminum projects and modernization of an existing aluminum plant. If the study results are favorable, Alcoa Engineers Inc. and the Import and Export Company of the Chinese Ministry of Metallurgical Industry could negotiate agreements to provide Alcoa technology and services for the projects.

Jan 1, 1979

By C. Lorimer Colburn, Spencer P. Howell

"Numerous accidents are still being reported that have resulted from the delayed explosions in drill holes. Some of these accidents have boon due to retarded burning of the fuse, causing the charge to explode after the miners had returned to the face, but the majority have been caused by the minors drilling or picking into unexploded explosives, either in unexploded bolas or in broken rock. Although the industry has been cautioned by the Bureau of Mines, manufacturers of explosives, and other agencies regarding the care that is necessary in the handling of explosives, yet reports of these accidents are still being received and many of the accidents are fatal, They occur in spite of the best efforts of the mine officials and men, but many of those that have been reported could have been avoided if the following precautions had been observed:Misfires should not be approached even for the purpose of inspection until three hours have elapsed if fuse was used, and ten minutes if electric detonators or electric igniters were used. These are minimum recommendations. It would be preferable to allow a longer time, for fuses have been known to hang fire for twelve hours."

Aug 1, 1920

By R. S. Dean

As set forth in the decision of the Trail Smelter Arbitral Tribunal, dated April 16, 1938 This Tribunal is constituted under and its powers are derived from and limited by the convention between the United States of America and the Dominion of Canada signed at Ottawa, April 15, 1935, duly ratified by the two parties and ratification exchanged at Ottawa, August 3, 1935 (hereinafter termed "the Convention") . . . The duty imposed upon the Tribunal by the Convention was to "finally decide" the following questions: (1) Whether damage caused by the Trail Smelter in the State of Washington has occurred since the first day of January 1932, and, if so, what indemnity should be paid therefor? (2) In the event of the answer to the first part of the preceding Question being in the affirmative, whether the Trail Smelter should be required to refrain from causing damage in the State of Washington in the future and, if so, to what extent? (3) In the light of the answer to the preceding Question, what measures or regime, if any, should be adopted or maintained by the Trail Smelter? (4) What indemnity or compensation, if any, should be paid on account of any decision or decisions rendered by the Tribunal pursuant to the next two preceding Questions? In this decision reported to the Government of the United States of America and to the Government of the Dominion of Canada, the Tribunal answered the first question in its entirety and reserved decision on the other three questions in accordance with the following extract from their decision

Jan 1, 1944

By B. D. Nash

The Bureau of Mines continued its research into the recovery of fluorine by the phosphoric acid acidulation defluorination of phosphate rock concentrates. A small process development unit with a capacity of about 10 kilo-grams of charge per hour was operated, and concentrates from both Idaho and Florida were processed. Over 80 percent of the fluorine was evolved and recovered as a dilute fluosilicic acid solution. Phosphate extraction from the concentrates always exceeded 98 percent. The fluorine was converted to a synthetic fluorspar product (3CaFa?SiOa) suitable for use as a slag conditioner in electric furnace steelmaking operations.

Jan 1, 1977

By George W. Heim

Before and during World War II, the Bureau of Mines investigated a large number of ore deposits in the United States and Alaska in a search for domestic sources of strategic minerals. Deposits chosen for development included those expected to contain metals of importance in the successful prosecution of the war. This report describes the work performed and results obtained in developing the Daggett Chief manganese deposit near Manila, Daggett County, Utah (fig. 1), during 1941. The work comprised mapping and a study of the geology by the Federal Geological Survey, and bulldozer and hand trenching, sinking of two shafts, and sampling by the Bureau of Mines. Work was started April 17, 1941, and was completed June 28, 1941. Two bulk samples for metallurgical testing were taken.

Jan 1, 1950

This summary of State laws on explosives wag compiled primarily to ascertain what subjects relating to their control have been acted upon by each State legislature and, in general, how they have been treated. It does not Include any legislation passed after 1942, or any proclamations, regulations, or administrative orders. It does not purport or attempt to be authoritative. If any problem arises involving interpretation of the statutes of any particular State, the original source must be consulted for the exact words used by the legislature. This summary, however, will be useful in determining whether relevant statutes exist, and in locating them quickly, with a minimum of effort. It will be of value also in comparing statutes in other States to determine what construction has been placed upon them by the courts of these jurisdictions or to contrast the varying provisions of many States upon a similar subject. To make these comparisons easier, the statutory provisions for each State have been grouped under several major topics in outline form. Although this sometimes has resulted in disruption of the continuity of individual acts, the increased general clarity and availability of comparable sections have more than justified the procedure followed.

Jan 1, 1943

By C. Thomas Hillman

The practical concern of economic minability of large, high-grade manganese nodule deposits in the northeast Pacific Ocean is addressed in this Bureau of Mines report. Principal objectives are to (1) estimate tonnage and grade of deposits with significant potential and (2) describe and estimate profitability of operations designed to mine and process deposits with greatest apparent potential. Analysis of data from over 800 ship stations identified three areas for detailed study. Average metal contents of these areas range from 1.30 to 1.45 wt pet nickel, 1.00 to 1.24 wt pct copper, 0.21 to 0.26 wt pct cobalt, and 26.8 to 27.8 wt pct manganese. Estimated recoverable nodule resources are 67.0, 66.9, and 148.8 million dry metric tons (t). A system to mine, transport, and process nodules from the three sites is described and costed. Although hypothetical, the system utilizes hydraulic mining and Cuprion (Kennecott) processing, which have been successfully tested at pilot scale. Nickel, copper, and cobalt are the three primary products, but ferromanganese is a considered option. Estimated capital requirements are approximately $1.5 to $1.7 billion for three-metal production. If ferromanganese were recovered, an additional investment of about $130 million would be required. Operating costs range from $71 to $83 per dry metric ton of nodules without manganese, and from $103 to $123 per dry metric ton with ferromanganese. Discounted cash flow analyses predict low returns, ranging from 2.7 to 5.2 pct with ferromanganese and from 4.1 to 6.0 pct without.

Jan 1, 1983

By David R. Wilburn

The U.S. Bureau of Mines investigated the resources, costs, capacities, market relationships, and short-and long-term supply of bauxite, alumina, and aluminum. The 45 evaluated mines and deposits in 14 market economy countries (MEC&apos;s) have a demonstrated resource of 8.4 billion mt of bauxite and an aluminum content of approximately 2.1 billion mt. Developed world bauxite resources and existing primary aluminum smelting and refining capacity are sufficient to satisfy demand through at least 1995, when additional properties (with higher cost levels) would need to be developed to satisfy future demand levels. It is anticipated that new alumina or aluminum production most likely would occur in developing regions with large bauxite potential, low-cost energy sources, and a close proximity to refining and/or smelting capacity. An increase in aluminum recycling capacity would help meet future demand increases. A series of network model supply analyses was performed for the period 1988 through 2000. Based on announced future production levels and assuming demand grows at the level outlined in the analyses, model results indicate there is sufficient material available to meet demand until 1998, where-upon an aluminum shortfall is projected. Additional analyses investigated the effect of a reduced growth rate of demand and regional production variations in Venezuela on the international aluminum industry.

Jan 1, 1993

The original manuscript of section 2 of this series of miners&apos; circulars devoted to accident prevention in bituminous-coal mines was completed in September 1944. At that time roof bolting had been tried with some success in the lead-mining district of south-eastern Missouri, but information on the subject was so fragmentary that it was not included as a method of roof support. References to roof support in bituminous-coal mines, therefore, were confined almost entirely to conventional timbering methods. In 1947 the Bureau instituted a research program and intensive study of the general problem of roof control, which emphasized roof-bolt application. The rapid increase in mechanized mining following the close of World War II provided the impetus for the Bureau&apos;s roof-control investigations, because the vertical supports used with conventional timber restricted the maneuverability of mechanical face equipment, and the industry wanted to explore every possible method of eliminating interference with the production cycle to gain full advantage of mechanized mining. Moreover, the accidental dislodgment of vertical supports greatly increased the roof-fall hazard. As roof falls have killed and seriously injured more mine workmen every year than any other cause or classification of injury since records have been kept, the Bureau assumed this investigative leadership with the prime objective of substantially reducing the annual toll from falls of roof, including falls of rib and face.

Jan 1, 1958

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