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By D. Harrington

"One of the underlying reasons for the establishment of the United States Bureau of Mines was the desire to promote greater safety in the mining and allied industries. Safety continues to be an important feature in the work of the bureau, and during the fiscal year 1929-30 the Bureau of Mines allotted $387,510 to the safety division out of a total appropriation of $2,249,670 (other than for helium).The safety division personnel consists of 22 engineers, 2 mine safety commissioners, 3 senior foreman miners, 18 foreman miners, 16 first-aid miners, 16 clerks, 10 cooks, and 3 laborers, a total of 90 persons. These safety workers are distributed through the 10 districts into which the United States has been divided for administration purposes. During the year 3 engineers, 1 senior foreman miner, 4 foreman miners, and 4 first-aid miners left the service. In general these men left the service to take up more lucrative positions.The 10 all-steel mine-rescue cars have headquarters as follows: Car 1, Reno, Nev.; Car 2, Raton, N. Mex.; Car 3, Pittsburgh, Pa.; Car 4, Terre Haute, Ind.; Car 5, Pineville, Ky.; Car 6, Pittsburg, Kans.; Car 7, Huntington, W. Va.; Car 8, Duluth, Minn.; Car 9, Butte, Mont.; Car 10, Des Moines, Iowa. There is also a mine-rescue car with headquarters at Juneau, Alaska. In addition, there have been established 11 mine rescue stations as follows: Birmingham, Ala.; Berkeley, Calif.; Seattle, Wash.; Evansville, Ind.; Jellico, Tenn.; McAlester, Okla.; Norton, Va.; Vincennes, Ind.; Wilkes Barre, Pa.; Salt, Lake City, Utah; and Pittsburgh, Pa.Every mine-rescue car and station is fully supplied with equipment and devices for use in case of mine fire or explosion, and at each station is an up-to-date automobile truck. At time of amine disaster the bureau's forces are immediately placed at the disposal of the authorities, State or company, with a view to giving such assistance as may be desired or available.The activities of the safety division at ordinary times are directed largely to securing and disseminating data on safety in mining. Among the numerous studies made, or being made, concerning safety and health in mining are those in connection with the causes and methods of prevention of mine explosions, explosibility of dust and gases, explosives and blasting, haulage, electricity, falls of persons or material, ventilation, dusts, high temperatures, timbering, lighting, machinery, and in fact practically anything which results or may result in acci¬dents of any kind in or around mines."

Nov 1, 1930

By H. P. Greenwald

[For sarno years past the Safety in Minbr. Resaarch J30ard of Great Bri tr-dn ha:1 been making ar.. intensive Gearch for, traterials that \.'ould be 1!\ore ef-ficient than rock dust and th t 'could l1eplace it Jholly or in El:}rt as a muans of prevEll'ltine the propa 'tion' of 'c63.1~dust exnlosions in. mines21 In the course of this \o.'ork several rock c.ur--ts md numerous inorganic compounds I,/ere tested. The result w place incombus.ti ble substFlnces in two main groups~ (1) r.:ho se who sa effect' in suppre aeina Jlihe cor.lbustion of coal dUDt i 0 pro-]

Jan 1, 1940

By R. W. Gurry

IN the course of a series of measurements of the rate of diffusion of carbon in austenite at about 960°C. (1760°F.) and 1110°C. (2030°F.), it became necessary to determine carbon concentration when austenite is saturated with graphite, because of indications that the hitherto accepted value of the solubility of graphite in this temperature range is too low. Specimens of carbonyl iron were saturated at temperature in a hydrogen-toluene atmosphere which was in equilibrium with graphite. The carbon content of the steel was measured either by combustion or by the loss of weight after substantially complete decarburization in an atmosphere of hydrogen saturated at room temperature with water vapor. The absence of carbide or graphite as a phase at temperature was demonstrated by microscopic examination of saturated specimens that had been drastically quenched. The mean result of concordant measurements is that gamma iron saturated with respect to graphite contains 1.39 per cent carbon at 957°C. (1755°F.) and 1.89 per cent at 1110°C. (2030°°F.). These two values, plotted along with what appears from the literature to be the best value (0.69 per cent) at the iron-graphite eutectoid temperature (738°C. or 1360°F.), yield a curve that is almost linear, and which, continued upward through a short interval, leads to a limiting solubility of 1.98 per cent at the iron-graphite eutectic temperature1135°C. (2095°F.) instead of the commonly accepted value of about 1.7 per cent. EXPERIMENTAL PROCEDURE The samples of carbonyl iron, with the exception of those for microscopic examination, were cylinders 3.8 cm. long, 0.475 cm. in diameter. They were placed in a graphite holder and suspended in a vertical furnace, the temperature of which was controlled precisely by means of the resistance of the platinum winding.1 In the empty furnace the range of temperature over a distance of 4 cm, at the heat center was 9°C. (16°F.) but at a given location the temperature remained within ±0.5°C. (0.9°F.); it was measured by inserting a platinum-rhodium couple calibrated at the melting point of palladium, 1555°C. Since the presence of the sample probably improved the uniformity of temperature, it was decided to consider the average temperature of the sample to be 3°C. lower than the maximum measured in the empty furnace with the same setting of the controller. Data were obtained in the vicinity of two temperatures, 960°C. (1760°F.) and 1110°C. (2030°F.). The samples for microscopic examination, 2.2 cm. long, 0.475 cm. in diameter, were suspended individually on pure iron wire; for these no temperature correction was applied. The carburizing gas passed into the furnace was dry, oxygen-free hydrogen saturated at room temperature with

Jan 1, 1942

By Hu Wenjun, Li Maonan

Mine ventilation systems mostly are ventilation networks with fixed-quantity branches. The solution to the problem of ventilation networks with fixed-quantity branches is obtained by choosing the fixed quantity branches as chords and using Hardy Cross iteration method. The solution usually is feasible but may be not economical. This paper takes minimal annual ventilation electricity cost as an object, considering the power of main fans and boosters, natural ventilation pressures and resistances of regulators, and builds up a nonlinear programming model. A set of initial values of the nonlinear programming can be obtained by using Hardy Cross method, The MAP technique then used to find a set of local optimal solution The running procedure with a simple example is dicussed. Mine ventilation systems mostly are ventilation networks with fixed quantity branches. In the networks, air quantity of branches are generaly regulated by increasing branch resistance or air pressure. A comon approch to the of the networks with fixed quantity branches is to formulate it based on Kirchhoff's current and voltage laws and the solution is obtained by Hardy Cross iterative technique. The solution usualy is feasible but may be not economical. The optimal plan of air quntities regulation of mine ventilation network should be to make the solution satisfy both required quantity of work places and minimal ventilation operating cost. It is the purpose of this paper to introduce a new approch and computational experience of nonlinear programming of the optimal problem.

Jan 1, 1991

By Mingchun Lu, Yunjin Yan

"This paper describes a new type of bell-less top installed on two relined blast furnaces at Tianjin Iron Works and another new-built at Echeng Steel Works in China. A compact installation was presented for existing furnace top innovation with the least reformation of existing top structure. A water cooling and sealing gearbox used for driving the chute discards completely the traditional idea about necessity of continuous supply of cooling gas for the gearbox. A multiring spreader and its dozens of selectable charging patterns enables an operator to achieve optimal burden distribution easily under the condition of a minimum investment of control equipment. Some useful conclusions have been made through a small-size model and a full-scale model tests. The excellent characteristics and the superiority of the new top have been fully proved at both works.IntroductionIt is known that there are some advantages with the bell-less top of a blast furnace: suitable for furnace to operate at high top pressure, capable of realizing optimal burden distribution, less investment and maintenance costs, etc. But why do most of blast furnaces in the world still remain using conventional bell top. One of the concerns is that current bell-less tops still have some shortcomings:1) The height of a current bell-less top might be lower than three or four-bell top or two-bell plus valve seal top, but still much higher than an ordinary two-bell top.2) The gearbox for driving the rotating chute is positioned onto the lip of the furnace. It is subject to attack by crude hot bf gas. Continuously pumping cooling gas (pressurized nitrogen or clean bf gas) into the gearbox is indispensable to withstand such a harsh working environment. Therefore, a plant furnished with blower8 and its ancillaries has to be built, It involves a large sum of investment and much expense in its annual running costs.3) Although the current bell-less charging device as a means of controlling burden distribution possesses a wide range of freedom, it is difficult to realize optimal burden distribution. There are some large blast furnaces realized better burden distribution, but sophisticated control means is indispensable so that the investment of control means is much higher."

Jan 1, 2000

By Richard E. Hucko

The U.S. Department of Energy (DOE) Coal Preparation Program focuses on providing the technical and process-development basis that can be utilized to produce environmentally acceptable clean-coal feedstocks for use as market conditions permit. A major objective of the Coal Preparation Program is the development of physical coal-cleaning technologies capable of significant removal of mineral matter and pyritic sulfur at high energy recovery levels.

Jan 1, 1989

By J. H. East, E. R. Maize

INTRODUCTION PROBABLY no other type of equipment is now being introduced into American underground mines about which less is known and about which there is more misinformation than the Diesel mine locomotive. Any equipment installed underground brings with it hazards that were not present before, and it is the purpose of this paper to show that Diesel-powered equipment can be used with safety in underground mining if certain feasible but very important precautions are taken. Diesel locomotives are not new in underground mining, since they have been used successfully in European mines for at least 19 years, but their use in American mines is exceedingly limited; so far as is known, only five Diesel mine locomotives are operating at present in United States mines. Diesel locomotives were permitted underground in Great Britain for the first time in 1939, and the rapid increase in the number in use in those mines, testifies to their safety and efficiency. More than 1300 Diesel mine locomotives are in use in European mines, according to the latest statistics; these locomotives are employed in coal, iron, lead-zinc and mercury mines. So far as is known, the Diesel mine locomotive has not yet caused an explosion or mine fire, and has not been the cause of any fatalities from toxic gases in the mines in which it has been used. ADJUSTMENTS OF DIESEL ENGINES FOR UNDERGROUND USE A Diesel engine adjusted to work in an underground mine should not be confused with the same engine adjusted for use outside the mine. Adjustment of the air:fuel ratio for engines that are used on the surface is intended to give the maximum fuel economy, and little or no attention is given to the chemical composition of the exhaust gas produced. Many such engines are poorly adjusted and perhaps poorly maintained, with the result that the engine emits smoke in quantity as well as the disagreeable odor familiarly associated with Diesel engines. The air:fuel ratio in the case of Diesel engines operated on the surface is generally around 15:1; that is, 15 lb of air to burn 1 lb of fuel. Diesel engines adjusted to work underground usually have an air:fuel ratio of about 20:I, as at this ratio the minimum quantity of toxic gases is given off in the engine exhaust. Diesel engines operated underground must be maintained in better condition than similar engines used on the surface; otherwise, the smoke emitted in the exhaust becomes objectionable if not unendurable. Practically normal air is required for safe operation of Diesel engines underground or in confined places; failure to provide virtually normal air for Diesel engine operation is almost certain to result in trouble. Bureau of Mines engineers have determined that the air in which a Diesel operates in confined places should contain less than 1/2 pct of carbon dioxide and at least 20 pct of

Jan 1, 1947

Consolidated Rutile Limited (CRL) was one of the best performing mining stocks of the turbulent 1980s, having a very high payout of franked dividends. In contrast to some other mining groups, it was not highly involved in the speculative lead-up to the 1987 sharemarket crash. Its base was firmly laid through a succession of decisions that were taken in the period 1982-1985. These decisions and the rationale behind them are outlined in this paper. CRL began the 1980s in a highly favourable position. It had successfully pioneered the transition to high-throughput mining of the high dunes on North Stradbroke Island (NSI), commissioning its 2100 tph cutter suction dredge at the Bayside reserves in 1978 at the time of rising prices, such that it was able to pay off its modest bank loan within 18 months. The June 1980 results showed a record after-tax profit of $5.6M, from total assets fo $26.5M and sales tonnages of rutile and zircon of around 50,000 tonnes each.

Jan 1, 1991

A good blending system is one that ensures that a plant can cope with the amount of grade variation that it will encounter. Prediction of amounts of variation that will be encountered on time or tonnage scales that are important should be regarded as an essential part of the planning of mines and plants. In some cases, the natural amount of grade variation when ore is mined and handled in the cheapest way will be acceptable. In other cases, it is necessary to understand the effects that various ore-handling processes have on amounts of grade variation at various scales and to design a blending system with considerable care. Blending tends to matter more when plants are sensitive to many aspects of grade. It can be very difficult to find the best compromise between capital cost and the amount of grade variation. In these cases it is important that ore blending options be considered carefully as part of the planning of mines and plants. Failure to make plans that consider likely amounts of variation can be very expensive.

Mar 1, 2010

By Georges Houlachi, Akram Alfantazi, Maysam Mohammadi

Manganese ions in zinc electrowinning electrolytes form a protective MnO2 layer that ultimately decreases Pb contamination in the zinc product. In this study, the effect of dissolved Mn2+ on the electrochemical performance of Pb, Pb-Ca and composite Pb-MnO2 anodes was investigated. The properties of the MnO2 layer formed on these anodes were studied and compared. Potentiodynamic polarization and cyclic voltammetry experiments were performed in 180 g L-1 sulphuric acid to study the electrochemical reactions occurring on the anodes. The anodes were subjected to galvanostatic polarization at 50 mA cm-2. The morphology and uniformity of the MnO2 layer on the anodes were examined using scanning electron microscopy (SEM). Experimental results revealed that the MnO2 layer formed on the composite anode was more compact and uniform compared to that formed on the Pb and Pb-Ca anode. It was also observed that the cell mud formation rate, and consequently manganese ions consumption, depended on the anode type. Although initial formation of the MnO2 layer decreased the oxygen evolution overpotential, its growth might negatively affect electrocatalytic activity of the anodes.

Jan 1, 2014

By Paul D. Tomlingson

Will Rogers unwittingly commented on the essence of evaluations when he said: "We don't know what they don't know!" In so doing, he explained why managers have an obligation to verify that their personnel really know what is expected of them. Rogers further stated that "What we know may not be so!" Here, he suggests that managers must establish the correctness of facts on which they make decisions concerning the future of their organizations. Yet, there are some managers who may not have considered this basic wisdom. These are perhaps the ones who shun a solid, fact-finding evaluation. Instead, they trust to guesswork as a basis for attempting improvement. Without realizing it, they may be making incorrect decisions harmful to the very organization they are trying to improve. Unfortunately, an attitude of avoiding evaluations often permeates whole organizations when their managers fail to appreciate their importance. Recently, the following was found prominently displayed in the office of a maintenance manager. Regrettably, the facts of a subsequent evaluation established how imprudent his attitude was:

Jan 1, 1991

By Santiago Gómez, Pablo Segarra, José A. Sanchidrián

In this paper, differences between the industry-standard Holmberg-Persson (H-P) approach and a semi-analytical vibration prediction model called full-field solution (FFS) are analized. The analysis is conducted at two levels: vibrations and rock damage.

Feb 1, 2020

By K. M. Myles

The vapor pressure of palladium over a series of Rlz-Pd alloys has been measured by the torsion-effusion method. The thermodynamic properties of the alloy system at 1575=K have been calculated from the vapor pressure data. The activities and the free energies of formation exhibit large positive deviations from ideal behavior. The enthalpies of formation are endother-mic. The entropies of formation are positive and larger than the ideal entropy of mixing. All of the thermodynamic properties suggest that a strong tendency toward phase separation exists in the solid solutions. The possible origin of the phase instability and the various factors that influence the thermodynamic properties are discussed. RECENT studies of the thermodynamic properties of alloys of palladium with nontransition elements have indicated that a significant contribution to the enthalpy of formation is related to the redistribution of the conduction electrons upon alloy formation.'-' The present work was undertaken to ascertain the importance of this contribution in Pd/transition-metal alloys. The Rh-Pd system was chosen for this investigation for several reasons: 1) The thermodynamics of the system were unknown. 2) Rhodium and palladium are completely soluble at high temperatures; below 1118OK the solid solution becomes immiscible.', 3) The difference in magnitude between the vapor pressures of rhodium and palladium permitted the use of an existing effusion apparatus. 4) Additional information was known about the alloy system that would facilitate the interpretation of the thermodynamic results. EXPERIMENTAL PROCEDURE The thermodynamic properties of the Rh-Pd alloy system were calculated from the vapor pressure of palladium over solid palladium and over several solid Rh-Pd alloys. The vapor pressure was measured by means of the torsion-effusion apparatus that has been described previously. In this method, an effusion cell is suspended from a tungsten filament inside a high-temperature furnace. Two orifices are located eccentrically such that the effusion of the vapor creates a rotational torque in the filament. The angle of rotation is directly related to the total vapor pressure within the cell. As the vapor pressures of rhodium and palladium are approximately five orders of magnitude apart," the total vapor pressure was considered to be effectively equal to the equilibrium vapor pressure of palladium. The effusion cells were made from high-purity alumina since auxiliary experiments indicated that essentially no reaction occurs between alumina and solid Rh-Pd alloys. Unfortunately, because the orifices were irregular, an accurate calculation of the Free- man-Searcy correction factors" could not be made. The constants were determined in an independent experiment where the vapor pressure of copper, as measured in the alumina cell, was compared with an accurate value of the vapor pressure, which had been determined previously.4 Depletion of palladium from the surfaces of the specimens was minimal as the deflection of the cell remained constant, for at least 15 minutes, at each of the experimental temperatures. Lattice parameter measurements of the postrun alloys also indicated that no changes in the composition of the surfaces had occurred. The alloys were prepared by arc melting the requisite amounts of the 99.99 pct pure elements. The four most palladium-rich alloys were remelted in a levita-tion furnace since complete melting of the components had not occurred in the arc furnace. All of the alloys were subsequently homogenized at elevated temperatures in sealed alumina thimbles. After heat treatment, the alloys were analyzed chemically and were in essential agreement with the nominal compositions. The thermal histories and nominal compositions of the alloys are given in Table I. Lattice parameters of the heat-treated alloys were computed, by means of the method described by Mueller et a1. ,I2 from X-ray diffraction powder patterns obtained with filtered copper radiation in a 114.6-mm-diam Straumanis-type Debye-Scherrer camera. The results, which are tabulated in Table I, exhibit a slightly greater negative deviation from Vegards' law than the values reported by Raub et al.13 The diffraction lines were sharp and well-resolved and thus indicated that the alloys were homogenous. RESULTS The logarithms of the individual values of the vapor pressure of palladium were fit, by the least-squares method, as a linear function of the reciprocal of the absolute temperatures. The constants of the equations are given in Table I along with the temperature range over which the data was accumulated. The latent heat of vaporization at 298.15"K for pure palladium, calculated by the third-law method,14 showed no systematic temperature dependence. The average value of 88,920 * 20 cal per g-atom agrees favorably with the average of the results obtained in the most reliable previous investigations.15"19 The activities of palladium were computed from the vapor pressure data at 1525', 1575", and 1625OK. Consistent with the mass spectrometric study of the atomicity of palladium vapor,lg the vapor was assumed to be monoatomic. The activities of rhodium were determined by integrating the Gibbs-Duhem equation with the aid of the a function.20 In the calculations, the activities of the pure solid metals were assigned the value of unity. From the activities, the partial and integral free energies, entropies, and enthalpies of formation at 1575° K were computed; they are assembled in Table 11.

Jan 1, 1969

The dielectric properties of practically all oxide and sulphide ore minerals are such that they heat rapidly when irradiated with microwaves particularly at the standard frequency of 2450 MHz. The presence of carbon or low rank coal mixed with the minerals still further enhances the heating rate. Amongst the patented technologies being investigated are: (i) the direct reduction of oxides with or without carbon included in the pellets or briquettes; (ii) microwave precursor heating of composites ahead of smelt reduction; (iii) microwave smelting of ore or concentrate mixtures with carbon, sometimes assisted with oxygen. Microwaves appear to stimulate endothermic reduction reactions as readily as they do exothermic oxidation reactions. Being a method of achieving "bulk" heating, composites or columns of ore-char blends rapidly heat throughout rather than from the outside inwards as in conventional heating. The microwaves of themselves do not generate any gas - the only gases to be cleaned are the products of reaction in the composites or blends, plus the products of oxygen smelting. In the case of sulphide composites, depending on the quantity and type of low rank coal or char present, sulphur may be eliminated, and collected, in the elemental form. Furthermore, reactions seem to take place at lower temperatures than in conventional smelting but no doubt at the "points" where actual reactions are taking place the atomic or molecular vibrations are such as to satisfy the laws of thermodynamics. Examples are given of the production of unusual products of smelting sulphide concentrates and also the alloys produced from refractory minerals such as chromite and ilmenite. The techniques have been used to produce products with as wide a range of melting points as relatively pure tin and tungsten-molybdenum alloys. Special equipment is being designed and evaluated for these new fields of pyrometallurgy.

Jan 1, 1989

By Bahjat Khoshaba, Bern Klein, Haixing Yan, Libin Tong, Andrew Bamber

"When a conductive or magnetic particle was put into an electromagnetic field introduced by an electromagnetic sensor, the particle can influence the electromagnetic field which can be used to characterize this particle. The electromagnetic technology based on eddy current theory was explored to investigate its potential in both the separation of minerals and the pre-concentration of a base metal ore. Samples tested in the study included the minerals obtained from Ward’s Science and the low grade copper ore particles obtained from Mount Polley Mine. The effects of mineral type, sensor frequency, particle size, particle position on the sensor surface, and particle lift-off on the magnitude and phase of the electromagnetic spectra were investigated. The electromagnetic spectra of various minerals show that it is possible to separate chalcopyrite or magnetite from tested minerals, simply based on the magnitude of the spectra. The spectra of the ore particles were determined by the mineral in the particles with the strongest signal. The effect of the pre-concentration of the low grade copper ore is determined by the association of chalcopyrite with magnetite. Direct sorting is the mechanism in the separation of mineral particles, while indirect sorting is the mechanism for low grade ores.INTRODUCTIONSensor-based sorting technologies include radiometric, X-ray transmission, X-ray fluorescence, near infrared, photometric, inductive, microwave heating and so on. Sorting not only discards barren rocks away from the concentrator but also recovers metal bearing that would be lose to the waste dump. The benefits of pre-concentration using sensor-based sorting are achieved on reduced energy consumption for comminution and reduced water usage on a volume per weight of metal basis (Bamber, 2008; Gunson, Klein, Veiga, & Dunbar, 2012; Kleine & Wotruba, 2010; Knapp, Neubert, Schropp, & Wotruba, 2014; Kobzev, 2014; Lessard, de Bakker, & McHugh, 2014; Mazhary & Klein, 2015; Robben, Wotruba, Robben, von Ketelhodt, & Kowalzcyk, 2013). Amongst others, high frequency electromagnetic sensors were developed for ore sorting at MineSense Technologies Ltd. and are subject of this paper. Improving the understanding of ore heterogeneity is the basis for developing a successful semi-bulk or bulk sorting systems by incorporating the sensors in the material handling equipment (MineSense Technologies Ltd., 2016). The present study focuses on the bulk sorting potential and bulk sorting mechanisms of the electromagnetic technology in the pre-concentration of minerals or ores."

Jan 1, 2016

By J. Fujioka, Y. F. Gu, C. Cui, D. Ping, A. Sato, H. Harada

"A new kind of cast & wrought (C&W) Ni-Co base superalloys named as ""TMW alloys"" are developed recently for compressor or turbine disks of gas turbine engines in High Temperature Materials 21 Project at National Institute for Materials Science (NIMS) in Japan. These Ni-Co base superalloys combine the characters of two kinds of y- y' two-phase alloys (Ni-base and Co-18at%Ti alloys) and have higher tensile strength and creep resistance than C&W UNDIMET 720Li superalloy."

Jan 1, 2006

By Albert W. Deurbrouck

This report describes the preparation characteristics of the significant coalbeds in Russell County , Va . Almost 2 million tons of coal was mined in 1961 ; 75 percent of the coal was cleaned mechanically in preparation plants in the county . The coal of Russell County is ranked as medium- to high- volatile bituminous , contains small amounts of sulfur , and generally requires some cleaning to reduce the ash content to limits acceptable for metallurgical purposes .

Jan 1, 1963

By B. F. Bush

THE coal-fields of Missouri, situated hi the northern and western portion of the State, are distributed, in whole or in part, over 57 counties, embracing an area estimated by Mr. Broad-head to be practically 23,000 sq. miles, including small detached beds and outliers in St. Louis, St. Charles, Lincoln and Warren counties in the eastern part of the State. This area includes about 8,000 sq. miles of Upper or Barren Measures, 2,000 sq. miles of exposed Middle, and 12,420 sq. miles of exposed Lower Measures. In a general way, the Missouri coal-field is bounded on the east by an imaginary line entering the northern part of the State just east of the 92c1 Meridian and passing across the State in a southwesterly direction to a point on the Kansas-Missouri line a little below the southern boundary of Barton county. An important part of the field overlaps this line and extends down the northern side of the Missouri river, under¬lying the greater part of Randolph, Howard, Boone and Audrain counties. In all, 34 counties produced coal during the year 1903. Fig. 1 shows the position of the coal-fields in Missouri. GEOLOGICAL FEATURES. The Coal Measure formations, all of the Carboniferous age, rest unconformably upon the rocks of the sub-Carboniferous or Mississippian series, and, in some cases, upon the rocks of the Devonian and Silurian ages. From their outcrop on the eastern and southeastern borders of the field, the Measures dip west to northwest at the rate of 10 ft. per mile, reaching a maximum thickness estimated by

Jan 1, 1905

By J. M. Seward, W. D. Dietzman, M. E. Hawkins

Analytical studies of formation waters are widely used by the petroleum industry as an aid in solving problems such as identifying intrusive waters , corrosion studies , treating injection water , and choosing open or closed water- injection systems . The solution of a problem is often simplified when reliable analyses of the waters under consideration have been made previously . Chemical analyses and electrical resistivity measurements are presented on 267 samples from 74 fields in south Arkansas , and 199 samples from 80 fields in north Louisiana .

Jul 1, 1960

By M. Tadayonsaidi

The effect of alloying elements on the mechanical properties and thermal expansion of 336 casting alloy usually used as piston alloy which has low thermal expansion and very good high-temperature mechanical properties and good wear resistance was investigated. The mechanical properties and thermal expansion characteristic of samples with different combination of alloying elements, which enhance to reduce the cost of products, have been studies, The results show remarkable increase in the mechanical properties with increasing the amount of Cu and Mg, while are reduced with increasing amount of Ni, On the other hand, the use of eutectic aluminum alloy as 336 alloy with higher percent of Cu and Mg and lower percent of Ni are recommended for industry, due to economical viewpoint and satisfactory properties.

Jan 1, 2005