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By H. B. Brunot

A complete list of permissible mine equipment, tested and approved by the Bureau of Mines previous to January 1, 1947, was published as Information Circular 7432.2/ A list of permissible mine equipment tested and approved by the Bureau of Mines during the calendar years 1947, 1948, and 1949 was published as Information Circular 7569. The present list supplements Information Circulars 7432 and 7569 and includes all of 'the equipment approved during the calendar year 1950. Information Circular 7465, which included a list of permissible mine equipment tested and approved by the Bureau of Mines during the calendar year 1947 therefore is superseded.

Jan 1, 1951

By R. F. Randolph, R. S. Fowkes, J. J. McClelland, G. H. Schnakenberg

Between 1986 and 1992, there were268 deaths and 54,642 severe injuries to workers in underground U. S. mining operations. Clearly, this level of health and safety risk is not acceptable. While most underground coal mining jobs are dangerous, some are much more dangerous than others. Many jobs in an underground coal mine are clustered around the working face—the place where machinery digs coal from the surrounding rock. The hazards in this area are numerous: When the coal is removed, the ground around it becomes unstable and can cave in on the workers. The mining machines used there are large, heavy, powerful, and move in many different directions in a very confined space, presenting danger to workers. Also, the machines churn up coal dust that causes black lung and other ailments. Figure1 shows a modern radio remote controlled continuous mining machine and its operator. In a typical mine, the jobs with the greatest exposure to hazards involve operation of machinery that cuts tunnel-like passages into the coal (the continuous mining machine) and machines that insert supportive steel bolts into the rock above the work area (roof bolting machines). The workers who endure these hazards are at almost twice the risk of death or disabling injury than co-workers in other safer areas of the mine. Of the statistics quoted above, 106 of the 268 deaths and 21,552 of the 54,642 severe injuries occurred in jobs involving equipment at the working face. The operators of roof bolting and continuous mining machines account for only 21% of the work force but suffered 40% of the deaths and 39% of the lost-time injuries during1986-1992. These death and injury rates are almost twice the rate for workers in other underground mining jobs (see figure 2). The estimated total cost of the 106 fatalities and21,552 lost-time injuries was $327 million from 1986-1992. On average, each fatality cost over $1 million and each lost-time injury costs in excess of $9,000.

Jan 1, 1994

By Ludwig Schmidt

[The attention of operators of oil-producing, properties long has been directed toward methods of disposing of petroleum wastes as well as the disposal of oil-field brines. The problem of disposing of petroleum wastes is not easy to solve, and although many operators are to be commended for the effort they have made, much work remains to be done before the Problem can be considered solved. Petroleum wastes include emulsions of petroleum and brine or matures of petroleum and sand that cannot be "broken down" or treated economically by known methods of separating petroleum from deleterious natter; crude petroleum that escapes from pipe lines, fittings, and tanks because of holes in the lines, leaky connections, or some accident; and oil-saturated materials that accumulate accidentally or otherwise in the normal operation of an oil-producing property.]

Jan 1, 1938

By Ludwig Schmidt

The attention of operators of oil-producing properties long has been directed toward methods of' disposing of petroleum wastes as well as the disposal of oil-field brines. The problem of disposing of' petroleum wastes is not easy to solve, and although many operators are to be commended for the efforts they have made, much work remains to be done before the problem can be considered solved. Petroleum wastes include emulsions of petroleum and brine or mixtures of petroleum and sand that cannot be "broken down" or treated economically by known methods of separating petroleum from deleterious matter; crude petroleum that escapes from pipe lines, fittings, and tanks because of holes in the lines, leaky connections, or some accident; and oil-saturated materials that accumulate accidentally or otherwise an the normal operation of an oil-producing property.

Jan 1, 1938

By Lester G. Morrell

THE WORLDWIDE economic expansion that has characterized the first 3 years of the 1960's continued through 1964 and was reflected in North America by strength in the industrial economy of the United States, which again was dominant. Advances in production were recorded in virtually all industries, including the mineral industry; 1964 mineral production established a new high, 5.4 percent above the previous peak recorded in 1963. However, the percentage increase in value of North American mineral production was slightly below overall economic growth. For industry in general, consumer demand held firm throughout the year and overall commodity prices averaged 2 percent higher than in 1963. Wages and salary payments also were up. With the single exception of the dock strike in the United States, the year was free of serious labor troubles and unemployment in both Canada and the States was at a low level. Despite the Viet-Nam situation, relatively tranquil international relations contributed to the forward movement of North American business. Total gross national product (GNP) for Canada and United States, in current dollars, was estimated at US$672.2 billion; 6.8 percent above the previous year's figure. Combined national income in 1964 amounted to US$546.9 billion, which was nearly 7.0 percent more than in 1963. In 1964, gains were recorded in each of more than 50 metals, nonmetals, and fuels commodities that comprise the North American output. The greatest category increase was 13 percent in metals, which was in part attributable to the 14 percent rise to a new record in value of iron and steel in United States, a 29 percent higher value of Canadian iron ore and a 57 percent rise in Canadian zinc. Despite a moderate decline in prices of iron ore and iron and steel products, generally favorable markets and rising prices for metallic ores and metals were a stimulant to the metals industry. Nonmetallic materials, with a total value in excess of US$5.25 billion were 7.3 percent higher than in 1963. High levels of highway and building construction and expanding demand for fertilizers and chemicals continued throughout the year. Noteworthy output increases were recorded for lime,

Jan 1, 1966

By Oliver Bowles

From the most remote periods of civilization, stone Las been used to perpetuate the memory of individuals or to immortalize their noble achievements. Ancient memorials ranged from simple piles of stone (cairns) or single markers to great obelisks and pyramid or magnificent mausoleums. The Taj Mahal at Agra, India, built of white marble by Shah Jehan in memory of the Empress Mumtaz Mahal, is one of the most beautiful and costly memorials ever built. It was erected between 1632 and 1050 at a cost estimated at a: high as $50,000,000, and it is today an object of unusual attraction for travelers. Other magnificent memorials, both ancient and modern, are to be found in many lands. Memorials of varying design have characterized the passing centuries and have found an important place in the New World. In early days, monuments were chiefly imported into America, but gradually an extensive memorial stone-manufacturing industry developed on this side of the Atlantic. Sales value of domestic memorials, f.o.b. quarry or mill, attained a maximum of $17,488,755 in 1920, and retail sales, of course, reached a much higher figure. Modest markers and tombstones are to be found in almost every rural community in the United States, and there are many elaborate and costly monuments in and near urban centers.

Jan 1, 1938

By Thomas M. Barczak

The safety of mine workers depends on the proper installation of roof supports to prevent the ground from collapsing into the working areas of an underground mine. As new support systems are developed, they need to be properly evaluated to make sure that they are capable of providing adequate roof support before they are first used in a mine. In addition to making certain that the supports meet basic safety criteria, the limitations of the support need to be fully defined in order to avoid improper application of a particular support design. The National Institute for Occupational Safety and Health (NIOSH) operates a world-class facility called the Safety Structures Testing Laboratory. This laboratory contains a unique load frame, the Mine Roof Simulator, which is capable of simulating the ground behavior in underground mines for conducting full-scale evaluations of roof support systems. Safety performance testing protocols using the unique Mine Roof Simulator have been developed for both standing roof support systems and longwall shield supports. The purpose of this paper is to describe these test procedures. The protocol for standing roof supports incorporates seven test series:( 1) uniform loading baseline tests, (2) height evaluations, (3) asymmetric loading, (4) biaxial loading, (5) load rate studies, (6) active loading determination, and (7) static loading evaluations. For longwall shields, a four-series test program that accurately simulates in-service conditions on a longwall face is proposed. This test program consists of (1) transfer of horizontal load to the caving shield-lemniscate assembly (zero-friction test),(2) point loading of shield joints due to lateral movement or rotation of the canopy, (3) evaluation of leg socketand leg cylinder integrity, and (4) face-to-waste racking of the shield. In addition, an evaluation of the shield’s hydraulic components will be conducted prior to the performance testing. These protocols will provide state-of-the-art safety performance evaluations of emerging support technologies, as well as a means to assess the safety of both new and aging longwall shields. Hence, this effort will enhance the safety of mine workers by ensuring that critical support elements are properly designed and that aging supports are retired before their support capability is jeopardized.

Jan 10, 2000

By T. L. Joseph

The purpose of this article is to describe briefly the operation of a 6-ton blast furnace on a charge of bauxite, limestone, iron ore, and cast-iron turnings and to point out the bearing which smelting such a charge has upon the production of alumina cement. One object of the experiment, conducted by the Bureau of Mines in cooperation with the Aluminum Co. of America, was to determine whether tae so-called Pedersen process3 can be applied to the blast furnace. This process consists of smelting a charge of bauxite, iron ore, and. limestone, and results in to products. One is a slag containing about 50 per cent of A1203 and is intended for use in manufacturing aluminum, and the other is iron low in sulphur. Complete details of the test are published in other reports4. Blast-furnace slag is now recognized as a satisfactory and economical raw material for making Portland cement, Wm. A. Forbes5 has recently reported that in 1926 an important steel interest used well over 1 million tons of slag in producing about 24 million long, tons of cement. This is equivalent to about ½ ton of slag for each ton of cement. Alumina cement can be made direct in the blast furnace. Its physical character would have to be changed by grinding, but no change in its chemical composition would be necessary.

Jan 1, 1928

By J. W. Miller

Depletion of coals most suitable for metallurgical fuel has made necessary a general survey of coking coal reserves in the United States. These investigations were begunn 1948 at the joint request of the Munitions Board, Department of Defense, and a number of coal companies. This report, which is one in a series, by counties, describes the preparation characteristics of the coals of Harlan County, Ky. From these data it is possible to determine: (a) Which coals, either as mined or after beneficiation by conventional preparation, are chemically suitable under present standards for producing metallurgical coke, (b) Which coals require special and more intensive treatment in preparation than is now practiced; and (c) Which coals cannot be considered to be potential sources of metallurgical fuel regardless of preparation.

Jan 1, 1955

By Lester G. Morrell

While developments in Australia dominated the minerals industry of the South Pacific area, New Caledonia's nickel, manganese ore from New Hebrides, gold from Fiji and New Guinea, and phosphate rock from several small islands were significant in world supplies of those materials. The total value of mineral commodities produced in this area in 1965 has been estimated at about $763 million an increase of nearly 16 percent over the value reported in 1964. Increases were recorded in mineral production value with respect to that of 1964 for all of the countries except Papua-New Guinea where lower gold output resulted in a drop of about $300,000 and in the several phosphate-producing islands that collectively recorded a value decline of around $1.3 million. Exploration and development activities continued at an intensified level, not only in Australia and New Zealand but also in the British Solomons, Bougainville, and Fiji. Substantial additions to world supplies of iron ore and bauxite are assured and recent discoveries of natural gas, manganese ore, and nickel combine to give Australia a brilliant mineral outlook. Important discoveries of copper on Bougainville Island and on Vanua Levu, the north island of the Fiji group, and a gold mine on Misma Island were being developed during the year, with plans for early production underway. In New Zealand progress has been made on the New Zealand Steel Company project, and preliminary appraisal of a new titano-magnetite beach sand resource on the South Island has aroused considerable industrial interest. Extensive geophysical investigations were carried out in the British Solomon Islands and on Fiji's goldfields. The expansion program that will double output of products by New Caledonia's Société Le Nickel continued through 1965, and several foreign private companies have expressed a desire to initiate additional industries based on nickel prospects in New Caledonia.

Jan 1, 1967

By W. M. Myers

[Utilization of small stone is recognized as one of the important problems of the lime industry. The term ?small stone' is used to designate material that is too small for calcination in tie shaft kilo. The maximum dimension A such stone rosy be placed at four inches. The introduction of any considerable quantity of stone having demensions lee: than this into the charge of a kiln impedes the draft and readers successful operation of the kiln difficult on impossible. Attempts design a shaft kiln which would calcine stall stone satisfactorily have not been successful to date. Thousands of tons of this small stone arc produced daily, and while part of it finds a market, for it has many uses, the profit is usually small an competition is teen and prices are low. Production of the material is, however, so greatly in excess of market that surplus of hundreds or possibly thousands of Jose axe place daily in stock piles and classified as waste. in a few instances a fortunate combination of circumstances, such as a program of or other work requiring large quantities of concrete aggregate, may mate it possible some quarries to market this stone later at a profit, teat in general the chances A profitable utilization are slight, and the quarry operator has the expense of handling this waste stone and providing a storage site for it. The brittle nature of limestone makes it impossible to quarry the stone and crush, it to size suitable for the shaft kilns without producing an excess of undesirable fines. Elimination of fines by changes in quarrying or crushing practices cannot lee expected. On the contrary, the adoption of more modern methods of quarrying in recent years has increased the proportion of small material. The tendency is to blast the roan with large charges of explosives and crush it with mechanical crushers, which produces more fines than the older methods of careful blasting with small char yes and sledging the rock by hand.. We increasing use of underground mining of limestone has also increased the production of small stone, as blasting in the confined space of an underground stope shatters the rocs more completely than quarrying in the open. The use of the very friable limestones, such as the limestone of Florida for the manufacture of lime adds a new factor to the calcination of small stone. These friable lime limestones have a low tensile strength and crumble in the kiln, causing trouble. Successful calcination of these stones is accomplished in specially]

Jan 1, 1926

By W. H. Ode

Low-temperature distillation tests at 200°, 350°, and 500° C. were made on a subbituminous coal from Boulder County, Colo., and a subbituminous coal from Weld County, Colo., in connection with a survey of carbonizing properties of American coals and investigations of their chemical and physical properties. The coal represented by the sample from Weld County was reported to give off combustible volatile matter at unusually low temperatures When placed on a fuel bed. The yields of tar and oil and the composition of the gas from this coal, as obtained in the distillation tests, did not confirm this report. These yields and the gas composition of the Weld. County coal differed but little from those obtained from the coal from Boulder County. Both coals yielded tar and gas in amounts considered to be normal for coals of their rank.

Jan 1, 1937

By S. H. Katz

In the Bureau of Mines investigations of respiratory apparatus, a laboratory study of dust respirators has been conducted, and the results will be published in detail as a technical paper. Many industrial dust respirators, and many fabrics and filtering materials were tested. The principal results of these tests, and the conclusions drawn from them, are presented below. Reference to the patent literature discloses numerous types of dust respirators, mostly based on the filter principle. The present study included only representative filter-type respirators, purchased on the market.

Jan 1, 1926

By Vernon O. Markworth

This report contains the results of tests performed on three large diesel engines to determine their ability to meet selected criteria of the Mining Enforcement and Safety Administration Regulations for equipment used in gassy, non-coal mines. Study efforts were first directed toward determining the types of equipment expected to be used in underground oil shale mines. Three typical engines in the 800-1200 horsepower range were then selected for testing. Intake flame arresters, exhaust scrubbers, and water jacketed exhaust system were designed and built for each engine. During testing, each engine was evaluated for its gaseous emissions output, adequacy of the exhaust gas cooling system, ability to withstand internal explosions, and adequacy of the flame arresters. Surface temperatures of the engine and exhaust cooling system were determined under full load operation.

Jan 1, 1978

By H. E. Powell

The magnetic susceptibilities of 34 manganese-bearing minerals were determined. The source of each sample and petrographic, spectrographic, and chemical analyses are given. Included are values for ismorphous series showing wide ranges of composition and for a few high-purity synthetic minerals.

Jan 1, 1968

By M. Kanefsky, A. Q. K. Rajput

Two channel polarity coincidence and polarity difference statistics are analyzed. The signal, common to both channels, consists of sinusoidal bursts where the exact frequency of the signal is nearly known, but other parameters such as amplitude, phase, and pulse starting time are unknown. The noise inputs are dependent, narrow band, Markov processes. It is shown that the performance depends not only on the signal uncertainties but on the precise shape of the cross-correlation functions between the noise inputs. By using two polarity difference statistics in addition to the polarity coincidence statistic, it is shown that the decrease in performance, as well as the cost of hard limiting due to correlated inputs, can be made small.

Jan 11, 1981

By S. J. Broderick

"INTRODUCTION Dark soils are commonly believed to be better for agricultural purposes than light-color soils. Much of this feeling may be purely psychological, as many persons have unconsciously acquired the habit of associating richness of soil with color light soils, however, may be just as rich in humus and plant foods as the best of the dark soils. A dis-cussion of the manifold attributes that play an important role in soil technology is beyond the scope of this paper, but the color factor will be considered, as it has a particular bearing on some field experiments using coal-mine waste as a darkening medium.It has been established that dark soils absorb more of the sun's radiation, consequently are maintained at a higher temperature than light soils. This physical principle is applied in our daily lives in the choice of clothing. White clotnes in summer are cooler than dark ones. Conversely, dark clothes in winter are warmer than light-color clothing. A decided advantage of dark soils over light soils is the higher average temperature of the former, resulting in an earlier maturing crop. This advance of the maturing season may range from a few days to a month, depending on such factors as climate, crop, and degree of color of the soil. It has been reported that in parts of Russia where the growing season is short, perhaps comparable to that in Pennsylvania and. New York, cotton has been grown successfully on soils originally of light color, but darkened with coal, dusts. The growth of cotton is, accordingly, speeded up a full month. 3/"

May 1, 1940

By Robert Howard

With the rapid depletion of the Peerless Coal Co.'s mine in Spring Canyon, it was necessary, if the company was to remain in the coal-producing business, to look to the development of a new property or to acquire a mine already developed. After careful investigation of several operating properties it was decided by the officials of the company to take over the lease on an undeveloped acreage held by a private party in Price Canyon, about 3 miles north of Castle Gate, Utah.

Jan 1, 1930

By J. A. McAllister, H. G. Iverson, K. C. Dean

"INTRODUCTION During the course of the investigation of the occurrence of manganese deposits in the western United States, laboratory studies of concentration were conducted at the Salt Lake City station on a sample of ore from the Lake Valley mines of the Newalpitt Fluorspar Corp. of Deming, N. Mex. The ore was reported to be representative of the type that would be mined for mill feed. The sample tested was found to be amenable to beneficiation by ore-dressing methods for the production of products that, when sintered, assayed over 44 percent Mn.At the beginning of the investigation of manganese-ore beneficiation in December 1940, the only product marketable to Metals Reserve Company was ferrograde manganese grade B, the requirements for which follow: Mn, min., 48 percent; Fe, max., 7 percent; Si02, max., 10 percent; P, max., 0.18 percent; Al203, max., 6 percent; Zn, max., 1 percent, Al2O3,Later the specifications were modified gradually. As of May 15, 1943, manganese products were acceptable if they contained over 35 percent manganese and less than 3 percent zinc and 1 percent phosphorus. Prices were based upon material containing 48 percent manganese, 6.0 percent iron, and 11 percent silica plus alumina. Premiums were paid for manganese content in excess of 48 percent and iron content below 6 percent, penalties being imposed upon products containing less than 43 percent -manganese, or more than 6 percent iron, or more than 11 percent silica plus alumina. The specifications for commercial manganese further required that maximum particle size be 12 inches and that, 75 percent of the product be coarser than 20-mesh. Therefore, fine material such as table and flotation concentrates had to be nodulized or sintered. In addition, oarbcnate manganese ores were not acceptable unless calcined."

Feb 1, 1948

By Philip C. Good

The Bureau of Mines investigated the feasibility of utilizing low-grade phosphatic shale as a feed for phosphoric acid production. Present practice in the phosphate mining operations of southeastern Idaho is to remove and either stockpile or waste low-grade phosphatic shales as the high-grade phosphate beds are selectively mined. Acid digestion studies were performed on uncalcined shale and on shale calcined to remove free carbon to determine phosphoric acid quality, yield, and amenability to filtration. The untreated shale, containing 21.4 pct P205, was digested with sulfuric acid in a single-tank reactor to yield phosporic acid and gypsum residue. Although 96 pct P205 recovery was attained in digesting uncalcined shale, only the calcined product gave satisfactory filtration rates. Calcined shale yielded phosphoric acid recovery of about 93 pct of the contained P205. It was higher in impurities than commercially prepared acid derived from high-grade western phosphate rock. An acid filtration rate of 745 lb P205/ft2/day was attained. This value is lower than the rate of 900 lb P205/ft that is generally considered to be acceptable in industrial production of phosphoric acid from high-grade phosphate rock.

Jan 1, 1981