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The U.S. Bureau of Mines and the U.S. Mine Safety and Health Administration (MSHA) are participating jointly in a research program to evaluate the strength characteristics and air-leakage resistance of various proposed seal designs for use in underground coal mines. The full-scale seals were constructed in the USBM's experimental mine at the Lake Lynn Laboratory, air-leakage tested, then subjected to pressure pulses of 20 psig or greater. In experiments prior to this study, seven seal designs using solid-concrete blocks were tested. Only the standard-type seal passed the explosion and air-leakage criteria. Tests also were performed on four seals constructed with low-density foam blocks. All four of these seal designs withstood the pressure pulse. In more recent studies, nine cementitious foam seal designs of varying thicknesses and densities were investigated. Six of the nine designs successfully survived the explosion overpressures. Six wood-block convergence seals also have been tested. The typical 3-ft-thick, wood-block seal design currently used in many coal mines did not maintain its integrity, in the absence of convergence forces, following the explosion test. Five modified wood-block seals successfully withstood the 20-psig pressure pulse. Based on these tests, three alternative seal construction materials, cementitious foam, low-density foam block, and wood, have been approved by MSHA for use in underground coal mines.

Jan 1, 2010

By J. B. Cunningham

Lithium in the form of metal, salts, and alloys is particularly important because of increasing industrial uses resulting partly from wartime developments. Lithium carbonate and lithium strontium nitrate, which impart a brilliant red color to a flame, are used in pyrotechnics. Lithium chloride and fluoride are used in fluxes for welding aluminum to dissolve the oxide coating on the aluminum and prevent oxidation of the molten metal. Lithium carbonate is used in ceramics in raw alkaline glazes because of its unusual fluxing properties. The use of 9 to 12 percent lithium carbonate permits a marked increase in the amounts of alumina, calcium, and silica that may be Used and results in a more stable glaze with sufficient alkalinity to produce vivid copper blues and other typically alkaline colors. Lithium stearate is used as a grease in airplane engines because of its ability to withstand wide changes in temperature. In view of its great affinity for nitrogen, hydrogen, oxygen, sulfur, phosphorus, carbon, and silicon, lithium has an excellent scavenging action on molten metals. It forms stable nonmetallic compounds of low specific gravity or gases that are eliminated at pouring temperatures. Lithium is generally added to the melt in the form of a lithium-calcium alloy consisting of 50 percent of each ingredient or as an alloy of 98 percent copper and 2 percent lithium. The lithium-calcium alloy added to cast iron before pouring, acts as a scavenger and increases the fluidity of the melt. This alloy also is said to increase the corrosion-resistant properties of stainless steel alloys and to improve their polishing qualities.

Jan 1, 1948

By Robert M. Becker

This investigation (in five parts) extends the theory of sample reliability from a sample consisting of a fixed number of items to a sample consisting of a fixed amount of items. Examples of a fixed amount of items per sample are samples consisting of a fixed weight or a fixed volume of unequal size particles. The extension of the theory is confirmed by experimental laboratory sampling using standard procedures. The probability distribution functions (the binomial, hypergeometric, multinomial, generalized hypergeometric, and those here called the compound binomial and compound multimomial functions) are developed from fundamentals. Their distributions are generalized to include some measured characteristic of the items. Infinite population moments are derived from moment-generating functions, and finite population moments are developed from corresponding infinite population moments using a newly defined mathematical operation. The first three experimental moments in laboratory sampling to given weights of particles are compared with the theoretical moments of their corresponding compound mult.inomial distributions. The agreement is striking. The study is divided into five parts. Part 1 deals with probability or random sampling to n items and with all sampling to n items per sample from some one probability distribution. This is the area of sampling covered by well-known theory. Accordingly, the procedures may be different but many of the results are well known.

Dec 1, 1964

By J. P. Walsted

Offgrade chromite concentrate, with a Cr-Fe ratio of 1.3 to 1.4 has been successfully smelted to produce useful ferroalloys. The Cr-Fe ratio is not improved, but the alloys can be used without a too drastic change in normal steel-mill practice. The ordinary high-carbon ferrochrome has been successfully produced by smelting under highly acid smelting conditions. An alloy containing 50 percent chromium was produced at a power consumption of 4,490 kw.-hr. per ton of alloy. Alloys containing 20 percent silicon were made by direct smelting chromite concentrate and silica.

Jan 1, 1956

By G. L. Oldright

By means of a technique developed in cooperation with the Eagle-Picher Mining & Smelting Co. and outlined in the first report of this series (R. I. 4333 ), it was possible to take many thermocouple readings with base-metal couples at temperatures over 2300° F with unsupported protection tubes for over half the lengths of the Henryetta retorts. -This technique made it possible to avoid the use of the usual optical pyrometer, which gives temperatures dependent upon the luminosity of the flames, and which is not conveniently usable to read temperatures for the lengths of the retorts from the front of the furnace. The temperatures of the retorts themselves were necessary in order to set upper limits for safe operation; the lower limits of operating temperatures are set by the zinc content of the retort residues. The zinc content left in the retort residues for various sections of length also varies with retort temperatures rather than with flame temperatures. The variations in temperature along the retort can then be used as guides to distill more zinc from the residues, to avoid fluctuations in the rates ,of flow of zinc vapor into the condenser and to employ lower temperatures if such rates become high enough to cause losses of uncondensed zinc.

Jan 1, 1948

By Oliver Bowles

[The inorganic nonmetallics - that is, all minerals aid their primary products except metallic ores and fuels - have an important place in industrial life of any country. They are essential to a multitude of products and processes, and their development is closely related to general industrial activity. Several are classed as strategic, and many others are performing necessary functions in the military program. It may be of interest therefore to trace their history over a period of years and to correlate their progress with the circumstances and events that are shaping national]

Jan 1, 1943

By W. R. Byrnes

This project was initiated on October 1, 1980 and will be completed on December 31, 1983. The project was Initially approved and funded by the Office of Surface Mining and subsequently was moved to the jurisdiction of the Bureau of Mines. It was administered through the Indiana Mining and Mineral Resources Research Institute. The research was done to assess reforestation success and ultimate productivity for areas reclaimed under the Surface Mining Control and Reclamation Act of 1977 (P.L. 95-87). The Permanent Regulatory Program for implementation of P.L. 95-87 Includes provisions for revegetation that require seeding of ground cover plants to control erosion until permanent vegetation such as tree species Is established, and restoration of mined land to its original or better productivity. Much of the land to be surface-mined presently supports forest cover and it is anticipated that reconstructed minesoils will exhibit high productive potential for hardwood tree species. Hence, information was needed on compatibility of ground cover and tree seedlings when established concurrently as well as on revegetation success under postmining versus premining conditions.

Jan 1, 1983

By Kenneth G. Skinner

The rapid growth of the metallurgical, chemical, and allied industries on the Pacific coast just prior to and during the war caused a sudden increase in the demand for refractories, which was the immediate cause of a revival in interest in refractory clays available on the Pacific coast, particularly in the Pacific Northwest. Population increases and shortage of shipping facilities caused an increase in the amount of various ceramic materials and products used and produced on the Pacific coast, with accompanying demand for information regarding sources of clay. In an effort to supply part of this information, the Bureau of Mines, in cooperation with the College of Mines, University of Washington, started a program in 1944 to test the refractory and other properties of clays from seven Pacific Northwest deposits that had been drilled and sampled as part of the Bureau of Mines alumina from clay investigation. Figure 1 shows the location of these deposits.

Jan 1, 1949

By W. W. Weller

Heat capacity measurements of anhydrous cobalt sulfate (CoSO4), copper sulfate (CuSO4), nickel sulfate (NiSO4), and zinc sulfate (ZnSO4) were conducted over the temperature range 51° to 298° K. The results were used to evaluate the following entropies at 298.15° K (cal/deg mole): CoSO4, 28.1; CuSO4, 26.8; NiSO4, 24.8; and ZnSO4, 26.4. Entropies were combined with heats of formation to give free energies of formation.

Jan 1, 1965

By W. P. Yana, J. B. Littlefield

"INTRODUCTION AND OBJECT OF EXPERIMENTAn explosion in and rupture of a gas-tight switch box on an electric loader in a mine located near Pittsburgh indicated that the cause was an internally generated inflammable gas-air mixture. This led to the suspicion that moisture condensation or ""other unusual conditions might have caused a spark or are across the surface of the material and that the heat may have created a carbonized path across the synthetic plastic base which would then conduct a large current with the generation of considerable heat and thermal decomposition of the base materials base in the box which exploded gave every indication that this series of events had taken place, and accordingly it was desired to determine what explosive gases such a decomposition of these insulating materials would produce.ACKNOWNLEDGMENTSThe desirability of making this investigation was suggested to the authors by L. O. Ilsley, supervising engineer, electrical section, Bureau of Mines, to whom the occurrence of an explosion in a switch box had been reported. The writers also acknowledge with thanks the assistance of L. B. Berger, chief scientific aide, health laboratory section, Bureau of Mines, in checking the calculations in the tables. DESCRIPTION OF MATERIAL INVESTIGATEDThe ten materials used in the tests, identified by letters A to J inclusive, are described in a succeeding list of materials. All the materials except I had a phenolic odor, especially when freshly cut."

Dec 1, 1932

By Wing G. Agnew, Paul L. Russell

"INTRODUCTION During the past few years, the development of millisecond-delay electric blasting caps has made possible a more flexible control over timing the firing of individual charges in blasting, The use of these caps has proved especially productive in quarry blasting and in numerous construction operations, but their use in underground mining is developing more slowly, although in some cases, as the solution to a difficult breaking problem, they have been well-received. When used in metal-mine drifts, the general objection is that the broken rock is thrown too far. In nearly all cases, however, use of millisecond-delay caps results in better fragmentation of the rock and a lower powder consumption per ton of rock broken.Prom 1949 to 1952, several series of experiments were conducted at the Mount Weather, Va., Experimental mine in conjunction with driving a 6- by 10-toot ventilation raise. 3/4/ The raise-round experiments in this 238-foot shaft, using millisecond-delay electric blasting caps in various drill-round patterns, are the subject of this report.SUMMARY AND CONCLUSIONSAll rounds discussed in this report were drilled in the hard rock (epidosite and greenstone) of the ventilation raise at Mount Weather Experimental mine (figs. 1 and 2). The drill-round patterns varied from 28- to 32 holes and from a V-cut design to one having no cut boles at all. With the exception of the first two rounds, all blasting was done with millisecond-delay electric blasting caps. In all rounds 60-percent ammonia gelatin dynamite was used and holes were stemmed with two cartridges of sand stemming."

Apr 1, 1953

By Eric E. Cather

A mineral survey of the Fisher Gulch RARE II area (A5299), Trinity County, California was conducted by the U.S. Bureau of Mines and U.S. Geological Survey. The Bureau of Mines was responsible for detailed examination of mines, prospects, and mineralized zones; the Geological Survey conducted geological, geochemical, and geophysical studies of the area. The area is underlain by the Salmon Hornblende Schist. Tonalite stocks 1.5 mi (2.8 km) to the east and northeast of the area intrude the schist and are closely associated with the nearby nines (Cox, 1967). The mines have quartz veins containing sulfides and gold in shears trending east to north past in the schist and tonalite (Hotz, 1972). Strewn and terrace gravel s occupy most of the drainages, many have yielded substantial quantities of gold.

Jan 1, 1981

By James C. Fowler

The design and field testing of a seismic miner detection and location system arc described. This work was carried out over a period of three years. The first two and one-half years were sponsored by Continental Oil Company, while the last period of tests were done as the first part of a one-year contract with the U.S. Bureau of Mines. Laboratory and field experimentation in three different nines under simulated emergency conditions have led to three important results: (1) Taps on roof bolts with normally available objects can usually be detected up to horizontal distances of 1,000 ft. (2) The origin of the tans can be located by on-site processing with a small computer. (3) Some predetermination of the approximate location is necessary for a quick and successful rescue. This report also includes preliminary specifications an,d cost guidelines for construction of a transportable field system capable of matching the performance characteristics of the one used during the field tests.

Jan 1, 1973

By J. W. Thompson

CONVEYANCE OF COAL IN PLACES. Coal or other mineral in place may be granted and conveyed as land, separate and apart from that which underlies or overlies it. Board, etc., of Greene County v. Lattas Creek Coal Co., 100 Northeastern, 561 (Indiana), January, 1913. MINERALS SUBJECT OF GRANT. Coal, mineral, and stone under the surface of the earth are the subject of grant and exception, and when excepted in a deed become a separate and distinct inheritance. Gordon v. Million, 154 Southwestern, 99 (Missouri), February, 1913. CONVEYANCE BY ONE COTENANT. One cotenant of land can not make a valid conveyance as against his cotenants of the minerals therein and a right to the small timber on the surface necessary for mining purposes with easements and full rights of way over the premises by the construction of roads, tram- ways, or railroads for the purpose of extracting, storing, handling, and shipping the mineral products. Ball v. Clark, 150 Southwestern, 359 (Kentucky), November, 1912. CONTRACT OF SALE COVENANTS RUNNING WITH LAND. Where a deed was made pursuant to a contract for the sale of certain copper-mining property at an agreed price, and at the same time and as a part of the same transaction a written agreement was

Jan 1, 1913

By John J. Sammarco

As part of a project to automate coal extraction, computer control of a continuous mining machine test bed has been developed and tested by the Bureau of Mines. A computer system and control software were developed for accurate positioning of the conveyor elevation and swing, stabilizer jack, gathering head, and shear elevation. Tramming actions are also controlled by the computer. The computer system was designed to access data from sensors installed on a continuous miner and to interface with the existing control circuits of the miner. Testing in free space was used to characterize the operation of the machine. From this information, control algorithms were written and stored in the computer. The ability to control each function of the continuous miner with a high degree of accuracy and stability was successfully demonstrated in a series of tests in free space and in mining a block of simulated coal. In the mining of simulated coal, the cutting drum was instructed to position the shearer at the top of the block and shear down to the bottom under closed loop control. The cutting drum came within 0.27 in of the top and within 0.49 in of the bottom of the block for this shearing test.

Jan 1, 1988

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 Lucia Kuizon

The Cactus Springs Roadless Area Review and Evaluation (RARE II) study area (No. A5188) comprises 12,800 net acres (5,180 ha) in San Bernardino National Forest in west central Riverside County, California, about 20 air miles (32 km) southeast of Palm Springs. Mineral investigations are made by the U.S. Bureau of Mines on National Forest lands identified as Further Planning Areas in the RARE II program. The Bureau of Mines reviewed literature, mining claim records, and production files; examined the study area; and mapped and sampled mineral properties where appropriate.

Jan 1, 1983

By Carl H. Beal

The oil industry in the United States is further advanced than in any other country, because of American initiative and the development of industries dependent in some way on petroleum or its products. For this reason the output has constantly increased (fig. 1), and as a result this country has produced more than half of the total output of the world. Trw total past output of the world is approximately 7,000,000,000 barrels of 42 gallons each; of this the United States produced about 4,000,000,000 barrels, or about 57 per cent. The limit of production in this country is being approached, however, and although new fields undoubtedly await discovery, the yearly outpnt must inevitably decline, because the maintenance of a given output each year necessitates the drilling of an increasing number of wells. Such an increase becomes impossible after a certain point is reached, not only because of a lack of acreage to be drilled, but because of the great number of wells that will ultimately have to be drilled. According to figure 1, the daily production per well each year has increased during the last few years. However, this increase is abnormal, being caused by the new pools brought in. Although such a condition may continue for several years, the average production per well will finally begin to decrease on account of the lack of new pools to make up for the normal decline in production of the old ones.

Jan 1, 1919

By G. L. Oldright

The studies previously made on Smelting in the Lead Blast Furnace have dealt with the custom smelter of the International Smelting Co. at Tooele, Utah, and on the smelter of the Bunker Hill & Sullivan Mining & Smelting Co. at Kellogg, Idaho. The International plant may be considered representative of the traditional custom smelter. The lead smelter of the future seemingly will have to treat increasingly richer lead charges. This feature was then stressed in describing the Bunker Hill plant.

Jan 1, 1934

By F. A. Patty

[Health and safety hazards from contamination of the atmosphere in places frequented by persons depend to a considerable extent on whether the contaminating agent possesses sense-perceptive properties which will give warning of its presence before it '.an create harmful conditions. If a distinct and easily recognized warning is given in advance of harmful conditions, hazards ace mitigated, but if warning properties are inadequate or absent, the hazards are augmented. When evaluating the hazard presented by a potentially harmful substance used under conditions of possible escape into the air of places frequented by persons, it is therefore necessary to consider the warning properties of the substance along with ether pertinent information such as toxicity, inflammability, physical properties, and mode of use. If the contaminating agent inherently lacks warning; properties it may be possible to impart them by adding to the hazardous substance a small quantity of a relatively harmless substance which has a high warning intensity.]

Jan 1, 1929