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By Ralph H. Kress

Haulage trucks designed expressly for mine service were introduced about 35 years ago. The first models to arrive on the scene hauled about 15 tons and easily outperformed the modified highway trucks that had been used for mine haulage up to that time. The specialized trucks obviously had a greater potential for mining operations, and once this fact was recognized, competitive pressures in both the mining and truck-manufacturing industries drove the new vehicles toward ever more efficient performance. Many changes in truck design resulted, but not all were accepted for a variety of reasons. Often poor design was the reason, but in many cases progressive and promising designs were abandoned only because the truck manufacturer lacked the courage, tenacity, or vision to capitalize on them. There were also many cases where a promising new design was abandoned because the prototypes were initiated in a mine where personnel lacked the patience to prove them. Truck Startup Takes A Team Ally new truck that is to succeed and contribute to lower mine haulage costs must be well conceived and launched with good teamwork on the part of all concerned. Naturally, it is essential to have a good overall truck design at the outset to make this teamwork worthwhile. The design must include the selection of the right components manufactured by suppliers that can each do justice to their particular part of the new truck. Last, but by no means least, the mine operator where the truck is to be launched must be enthusiastic in his efforts to see the new vehicle through to successful operation.

Jan 1, 1971

By E. J. Westerman

Prealloyed powders of nickel-base superalloys were sintered to almost theoretical density in short sinterilzg times. It was ascertained that the rapid densification was caused by a small amount of liquid phase at the grain boundaries, which apparently ovriginated by incipient melting at temperatures considerably below those at which macroscopic melting of the compacts occurred. An increase in the quantity of liquid phase present during sintering-, caused by an increase in the sintering temperature, increased the densification rate, but resulted in a decrease in the room temperature tensile propevties. NICKEL-base superalloys, which presently comprise an important group of high temperature alloys, are difficult to fabricate by the forging, casting, and machining operations presently used. As it was felt that fabrication by powder metallurgical techniques might offer advantages in the production of super-alloy parts, a basic investigation of the most important process in the sequence of powder metallurgical operations, the sintering process, was undertaken on Rene 41, Udirnet 500, and Nimonic 90 and 100 powders. These alloys age harden by the precipitation of the ? Ni, rA1,Ti) phase. Nickel-base superalloys of the Nimonic type have been fabricated by powder metallurgical methods, and their mechanical properties reported in detail.' Other alloys for high temperature service which have been fabricated by powder metallurgical methods include a Co-base alloy of the Vitallium type;2,3 alloys with a Co-Ni-Fe-Cr base;4 stainless steels;5'6 Cr-W-Co alloys;" and a Co-base alloy, X-40.8 METAL POWDERS The superalloy powders investigated were: a) a prealloyed at.omized Rene 41 powder; b) a prealloyed atomized Udirnet 500 powder; c) a prealloyed atom-

Jan 1, 1962

By G. F. Tagg

Earth-resistivity measurements are often of service in obtaining information regarding geological formations, particularly when applied to structural problems. In such problems the masses of the various bodies are large, and have a corresponding effect on the average resistivity of the soil. Much work has been done using such measurements, but in general the method of interpretation employed is empirical. Since certain simple cases can be investigated mathematically, it appears to be quite sound to endeavor to apply the mathematical solutions to the practical results, in order to deduce from the latter such unknown quantities as depth. This paper deals with such a method of interpretation for the simple case of a single horizontal stratum. In the method described by Wennerl for measuring earth resistivity, four stake electrodes are driven into the earth in a straight line as shown in Fig. 1. A current I amperes is passed between the two outer stakes and the potential difference V volts between the two inner stakes is measured. Then if a is the electrode separation, the specific resistance of the soil, which is assumed to be homogeneous, is given by the formula P = 2?v/1 [1] v or if v/1 is called a resistance R ohms, p = 2?aR [2] If a is in inches, p will be in ohms per inch cube, or ohm-inches, and if a is in centimeters, p will be in ohms per centimeter cube or ohm-centimeters. As stated above, this formula is true only if the earth is homogeneous, and when this is not the case an application of one of these formulas

Jan 1, 1934

By C. R. Claus, G. A. Standish

Since March. 1945, the Magnolia Petroleum CO. has drilled 39 wells in Southwest Coastal Louisiana. All wells were drilled within a comparatively small radius, but the area provides a large variety of problems. The deepest well drilled was 13,518 ft, and the total depth averaged 10,977 ft. Throughout this period drilling mud control and types of mud handled were: (I) phosphate, (2) red lime (late conversion), (3) red lime starch (early conversion), (4) red lime starch oil emulsion, (5) precision controlled low alkalinity-low lime content. and (6) gel muds for completion purposes. Improvement has been obtained in effecting some or all of the following: (I) more rapid penetration, (2) reduction in drilling hazards, (3) better evaluation of cores and logs, and (4) better completions. The geological sequence of zones penetrated range from recent sediments at the grass roots through the Frio section. Anticipation of high-pressure zones and incompetent formations entails precision control of drilling mud weights, and the unconsolidated nature of the various zones requires constant attention to the filtrate, viscosity, and gel strength values. In the Chalkley field, particularly, this combination of problems exists, where the formation pressures and overburden weight density values are in very close proximity. Design of casing and drilling mud programs must be modified to fit each well. INTRODUCTION Field and research work on drilling fluids has made constant progress, enabling operators to prospect progressively deeper horizons. Numerous papers have been written on the theoretical aspects of drilling fluid devel- opment, but in the field engineers have found it difficult to evaluate the role of specific mud constitutents when dealing in terms of thousand barrel mud systems. For that reason field data is somewhat lagging in technical report writing. However, applications of new techniques in the field have usually paralleled, and in numerous instances preceded, research work. The information obtained by Magnolia Petroleum Co. in the course of drilling 39 wells within a comparatively small area in Southwest Coastal Louisiana provides an excellent opportunity of reviewing a specific example of drilling mud evolution. A large variety of problems has been coped with, the most important result being that every well was successfully drilled to its projected total depth. The discussion begins with the advent of deep drilling in this area in March, 1945, and is concluded with a resume of recent drilling operations in the Chalkley field. The primary purpose of this paper is to describe the evolution in types of drilling fluids as it occurred and its application in the solution of various drilling problems. All of this information and experience resulted in the successful drilling of the three wells in the Chalkley field, where a combination of the most sound techniques was necessary in carrying drilling operations to the projected total depths. Other operators along with service company engineers have contributed considerably through the interchange of ideas and information to this paper, but the data and conclusions which are contained are based on first-hand observation of Magnolia Petroleum Company's drilling operations. The 39 wells drilled by Magnolia Petroleum Co. average in depth 10,977 ft per well, while the maximum depth penetrated was 13,518 ft. The cost of drilling fluids have varied from $8,700 to $165,000, with the over-all drilling costs ranging from $74,000 to $543,000 per well. This wide variance illustrates the unpredictable nature of each well and the effects on over-all cost when high density muds are required to control

Jan 1, 1955

By Henry M. Howe

Jan 1, 1909

By F. X. Tartaron

This article is a continuation of a previous paper by the writer in which Kick's Law was stated to be a part of comminution theory. ln the present paper, a broadening of ideas is attempted in order to state a general theory. The word "general" is employed because the new theory includes all previous laws and generalizations which are considered to be essentially correct. These ideas are combined into a coherent whole and the general theory can be expressed by the equation In the author's previous paper on comminution, ' the equations developed were based on Charles' equation of exponents a-n +1 = 0. 2 This paper is divided into two parts, designated as First Approach and Second Approach. In the First Approach, the equations of the previous paper are utilized, with Charles' equation of exponents being necessary. In the Second Approach, a separate and independent method is used to derive the same conclusions as in the First Approach, but without the use of Charles' equation of exponents. Holmes accepts the theoretical foundation of Kick's Law as sound but denies that the law as such operates in comminution. His idea is that Kick's Law requires homogenous matter whereas the presence of cracks, flaws and cleavage planes, which predominate in the coarser particles, makes matter unhomogene-ous. This explains why there is no experimental evidence to support Kick's Law. However, since the basis of the law is theoretically sound, all experimental evidence must be viewed as emanating from it. This requires modification of current comminution equations to fit this concept. Holmes makes the modification by changing the constant exponent n in the general energy equation used by Charles (E = - JCdx/xn) to a variable exponent r. The writer asserts that Kick's Law operates in comminution without modification but it does not

Jan 1, 1963

Jan 1, 1957

By J. Chipman, N. J. Grant, H. L. Bishop

Lime and dicalcium-silicate crucibles were equilibrated with molten iron and liquid slags containing iron oxide and small amounts of sulfur. The oxygen content of metal, iron oxide activities, and desulfurization values of the slags were determined in the temperature range 1530 to 1700°C. The influence of magnesia in the slag and the temperature dependence of the solubility of lime in liquid iron oxide and the ferric oxide content were established. The temperature contour of the liquidus surface of iron-silicate slags saturated with lime and dicalcium silicate was also established at 1600°C. THE importance of the role that slag composition plays in the refining of steel has been known for many years. Numerous studies have been made using actual plant data in order to establish the relationship between the composition of the slag and metal during the refining of a heat of liquid steel. These results rarely represent equilibrium conditions since completion of the various chemical reactions involved in steelmaking is seldom realized. In order to establish quantitatively the equilibrium conditions existing between the slag and metal, several laboratory studies have been conducted in the past 20 years to determine the reactions important in slag control. These investigations have included studies of simple liquid basic and acid slags as well as more complex slag systems which approach those commonly found during the refining of a heat of steel. Since most of the previous studies of simple basic iron-oxide slags equilibriated with molten iron were made in magnesia crucibles, it was not possible to establish the distribution of sulfur and oxygen between molten iron and slags consisting only of the three essential components, lime, silica, and iron oxide. This investigation was undertaken to establish the equilibrium conditions for simple lime-iron oxide and lime-silica-iron oxide slags. Accordingly, it was expedient to prepare crucibles both of lime and dicalcium silicate to establish the equilibrium conditions between molten iron and iron-oxide slags saturated with the refractory materials and free from other components. The only other studies of the equilibrium between molten iron and lime-saturated slags are those of Fischer and vom Ende, 1, 2 in which the solubility of oxygen was determined in an air atmosphere. The

Jan 1, 1959

By Geo. H. Ashley

THE present critical state of the supply, distribution, and utilization. of coal and the necessity for pooling and zoning coals calls renewed attention to the lack of any fully adequate classification of coal. In the past coals have been classified as anthracite, semianthracite, semibituminous, bituminous, subbituminous coals, and lignite, and a few special types, such as splint coal and cannel coal. But under the term bitumi¬nous coal are included a great variety of coals differing markedly both physically and chemically. The term subbituminous coal covers as great a range of chemical differences. In order to distinguish these varieties of bituminous coals it has been customary to designate coals by names derived from the place where mined, or by the name of the bed from which it is mined. Thus, in the market reports, coals are quoted as Pocahontas coal, New River or Sewell coal, Moshannon coal, Ohio coal, Williamson County coal, Jellico coal, and so on indefinitely, no limit being set as to the boundaries of the area to which a given name is applied. Nor is there any scale by, which the coal from one place may be compared with the coal from some other district or some other bed. On the one hand, coals from the same district may be quite distinct and sell at very different prices or coal from the same bed may differ greatly in different districts; on the other hand, coals from different states may be so similar physically and chemically that one could replace the other in practical use without any appreciable difference in service.

Jan 8, 1919

By Harmel A. Dawson, Robert A. Wilson

First the basic steps to determine the values present and the minerals involved which are the basis for the metallurgical testing are presented in this paper. Next, choosing the process or processes indicated for treating an ore are discussed. This is followed by the test procedures used, the results of which will indicate amenability to treatment. These test procedures have been developed, used and proven effective in laboratory evaluations relative to plant processing. Special, uncommon processing is beyond the scope of the paper. Evalutation of test results and incorporation into the preliminary and final flow sheet for plant design are discussed. The value of a flow sheet, with material and water balances, to plant design is shown.

Jan 1, 1978

By H. F. Moore

Jan 1, 1936

By Benjamin L. Miller, Charles H. Breerwood

From earliest recorded times, limestone has been employed in the industrial life of peoples of all sections of the world where it exists. It is widely distributed and therefore has been available in almost every country and has been employed for a variety of purposes. Its earliest use was for buildings, since it is more easily quarried and dressed than most other kinds of rocks and so could be utilized by early inhabitants, poorly equipped with tools. The next use was in the manufacture of lime, which was employed by the ancients in mortar. These two uses of limestone are still all important, but they have been overshadowed in scores of regions by literally hundreds of new applications for raw limestone or products made from it. Anyone familiar with modern manufacturing processes can quickly call to mind many industries in which limestones are essential, and new uses are continually coming to notice. Any enumeration would probably be incomplete and soon out of date. Origin of Limestone Disregarding details and unusual types concerning which often there is insufficient evidence and considerable difference of opinion, limestones have been formed by the precipitation of calcium carbonate from solution through the action of organisms, both plants and animals, or in a limited number of instances by chemical reactions without the intervention of living forms. Some of the organisms extracted the calcareous material in order to build up hard structures, either as bony skeletons or as coverings (clams, snails, etc.), whereas others in their life functions emitted substances that resulted in the precipitation of the soluble constituents outside the organisms themselves. In some instances the organisms utilized only calcium carbonate but in some cases other compounds as well were precipitated. Various materials have been found in the hard parts of animals, and for that reason it is almost impossible to find a pure natural limestone; that is, one composed entirely of CaCO3.

Jan 1, 1938

By S. N. Kesten, Richard Murphy, A. H. Land, W. F. James

Introduction—by W. F. James and A. H. Lang This paper describes the geology and present state of development of uranium and thorium deposits in Canada. It is expected that this information will be added to that now being assembled from available American and British data to provide a background for engineers and others who may be called upon in the future to examine or search for radioactive deposits. Some generaliza- tions regarding the Canadian deposits are included, but many of these are necessarily tentative. The information contained in the paper is up to date for the end of 1948. The information contained in this paper has been derived from many sources. Much of it is from the records of the Canadian government-owned Eldorado Mining and Refining (1944) Limited and from examinations of government and private properties made by officers of the Geological Survey of Canada. Some information on privately-owned properties has been quoted from other sources mentioned in the text. The information has been assembled by W. F. James of Eldorado Mining and Refining (1944) Limited and A. H. Lang of the Geological Survey of Canada, who have written the sections for which they are credited. The description of the Eldorado mine is based on reports by Richard Murphy, formerly chief geologist for Eldorado; the report by Mr. Murphy was published previously by the Canadian Institute of Mining and Metallurgy,' to whom the writers are indebted for permission to repub-lish. The section dealing with the geology of and development work in the Goldfields area, where Eldorado has important holdings, is by S. N. Kesten, field geologist for Eldorado. The geological diagram of the Goldfields area (fig. 2) was kindly supplied by A. M. Christie of the Geological Survey of Can-

Jan 1, 1951

By Charles H. Breerwood, Benjamin L. Miller

From earliest recorded times, limestone has been employed in the industrial life of peoples of all sections of the world where it exists. It is widely distributed and therefore has been available in almost every country and has been employed for a variety of purposes. Its earliest use was for buildings, since it is more easily quarried and dressed than most other kinds of rocks and so could be utilized by early inhabitants, poorly equipped with tools. The next use was in the manufacture of lime, which was employed by the ancients in mortar. These two uses of limestone are still all important, but they have been overshadowed in scores of regions by literally hundreds of new applications for raw limestone or products made from it. Anyone familiar with modern manufacturing processes can quickly call to mind many industries in which limestones are essential, and new uses are continually coming to notice. Any enumeration would probably be incomplete and soon out of date. Origin of Limestone Disregarding details and unusual types concerning which often there is insufficient evidence and considerable difference of opinion, limestones have been formed by the precipitation of calcium carbonate from solution through the action of organisms, both plants and animals, or in a limited number of instances by chemical reactions without the intervention of living forms. Some of the organisms extracted the calcareous material in order to build up hard structures, either as bony skeletons or as coverings (clams, snails, etc.), whereas others in their life functions emitted substances that resulted in the precipitation of the soluble constituents outside the organisms themselves. In some instances the organisms utilized only calcium carbonate but in some cases other compounds as well were precipitated. Various materials have been found in the hard parts of animals, and for that reason it is almost impossible to find a pure natural limestone; that is, one composed entirely of CaCO3.

Jan 1, 1938

ALABAMA. Anniston.-Noble, A. E., 20th St. and Wilmer Ave. Auburn.-Brown, R. L., Box 0. Belle Ellen.-Hutcheson, W. C. Bessemer.-Abbott, C. E., T. C., I. & R.R. Co Dobbs, G. G., Box 97. Ferguson, V., U. S. C. I. Pipe & Fdy. Co. Williams, E. P., Tenn. C., 1. & R. R. Co. Birmingham.-Aldrich, T. H. Aldrich, T. H., Jr., 406 Woodward Bldg. Allen, A. W., 1616 S. 14th Ave. Bowron, J., 1401 S, 20th St. Burbidge, T. A., Brown-Marx Bldg. Coxe, E. H. Tenn. C., I. & R. R. Co. Crawford, C. G., Tenn. C., I. & R. R. Co. Crockard, F. H., Brown-Marx Bldg. Ellis, E. E.,1515 Brown-Marx Bldg. Fairbairn C. T., Woodward Bldg. Fies, M. H., 2316 Highland Ave. Geismer, H. S., Keiser-Geismer Engrg. Co.

Jan 1, 1917

By H. F. Moore

Jan 1, 1936

By William G. Pariseau

The flexure of geologic strata, a phenomenon of interest to geologists and mining engineers alike, is examined as a sheet bending problem in Coulomb plasticity. Fonnulae for the distribution of stress, strain, and displacement increments; volume change; change in the length of the central surface; and power of dissipation, as well as for the neutral surface shift are given. Strains of any magnitude are considered. The analysis shows that deeply buried strata may bend and develop "tensile" cracks under generally compressive states of stress. It is also shown that bed separation and high capacity props are desirable in mechanized longwall mining, a result in keeping with operating experience. Although speculative at this time, the analysis provides a rational working hypothesis as regards the problem of strata flexure and control. | he purpose of this paper is to present an analysis of the flexure of geologic strata as a problem in the bending of a sheet of material failing in accordance with a Mohr-Coulomb criterion. The flexure of strata has an obvious academic interest to the geologist concerned with the mechanics of folding. It is of interest to the economic geologist as it relates to the structural control of certain types of ore deposits. It has an intimate association with mine subsidence phenomena, and is of concern to the mining engineer. Strata flexure is also the dominant feature of roof behavior about longwall workings. An improved understanding of strata flexure through a rational mechanical analysis thus appears desirable not only from the academic view but from the economic one as well. In the field, the most commonly observed feature of folding, subsidence, and longwall roof behavior is the permanent and therefore inelastic nature of the strata movement. Fig. 1 illustrates the physical disposition of strata in the vicinity of a longwall face. Inasmuch as most rocks (with the possible exception of certain evaporites) do not exhibit significant viscoelastic behavior, at least not over time spans of engineering interest, a plastic analysis is indicated. The analysis is meant to apply to strata whose deformation is dominantly that of bending such as might be expected in the remote roof about a longwall face.

Jan 1, 1970

By W. F. James, Richard Murphy, S. N. Kesten, A. H. Land

Introduction—by W. F. James and A. H. Lang This paper describes the geology and present state of development of uranium and thorium deposits in Canada. It is expected that this information will be added to that now being assembled from available American and British data to provide a background for engineers and others who may be called upon in the future to examine or search for radioactive deposits. Some generaliza- tions regarding the Canadian deposits are included, but many of these are necessarily tentative. The information contained in the paper is up to date for the end of 1948. The information contained in this paper has been derived from many sources. Much of it is from the records of the Canadian government-owned Eldorado Mining and Refining (1944) Limited and from examinations of government and private properties made by officers of the Geological Survey of Canada. Some information on privately-owned properties has been quoted from other sources mentioned in the text. The information has been assembled by W. F. James of Eldorado Mining and Refining (1944) Limited and A. H. Lang of the Geological Survey of Canada, who have written the sections for which they are credited. The description of the Eldorado mine is based on reports by Richard Murphy, formerly chief geologist for Eldorado; the report by Mr. Murphy was published previously by the Canadian Institute of Mining and Metallurgy,' to whom the writers are indebted for permission to repub-lish. The section dealing with the geology of and development work in the Goldfields area, where Eldorado has important holdings, is by S. N. Kesten, field geologist for Eldorado. The geological diagram of the Goldfields area (fig. 2) was kindly supplied by A. M. Christie of the Geological Survey of Can-

Jan 1, 1951

By T. D. Lynch, N. B. Pilling

The development of a proper treatment for shells in conncction with war contracts has brought to our attention the fact that the temperature of the liquid bath in which steel is quenched has a decided influence on the speed of cooling in the case of some liquids and very little in the case of others. Widely different physical results have been obtained by the use of water spray, water immersion, and oil immersion and further experiment has shown that the quenching effect of water used as a spray or an immersion varies greatly with the temperature of the water. The present experiments were undertaken with the idea of obtaining information of a quantitative nature regarding the quenching properties of a number of liquids used commercially in hardening steel. The general features of such cooling media are common knowledge and in the literature may be found records of numerous attempts to evaluate the cooling power of a liquid when used as a quenching bath. Much, if not most, of the data given on this subject is in the form of a simple statement of the time required for a certain heated mass to cool between two arbitrary temperatures when immersed in the liquid, quite regardless of the path of the temperature change. Our own purpose has been somewhat different. We have attempted to isolate that property of these liquids having to do with their ability to absorb heat rapidly, as distinct from the behavior of a considerable mass when exposed to different thermal environments. More specifically, from the data obtained through autographically recorded cooling curves of a small standard mass quenched under various conditions, we have tried to analyze the mechanism of heat absorption by the several liquids, measure the changes in its rate as a function of the temperature of the surface of transference, and ascertain the influence of the temperature of the liquid itself upon both. Without attempting an exhaustive citation of the literature, mention may be made of some of the more important contributions, notably the pioneer work of Le Chatelier,' followed by the extensive investigations

Jan 1, 1920

By D. D. Pollock, D. I. Finch

Relationships between the compositions of specially prepared manganin-type alloys and some of their electrical properties have been established. Empirical equations, based upon the electronic configurations of the alloying elements, are given which describe the resistivity, temperature coefficient, peak temperature, and thermoelectric power of Cu-Mn-Ni-Fe alloys at approximately room temperature. Calculations based upon these relationships are correlated with experimental data. SECURING suitable alloys for the construction of stable resistors, for use in precise electrical measuring devices, has been important ever since the art of electrical measurement was begun. German silver, Pt-Ag, and Platinoid are examples of some of the alloys in early use. These early alloys were un- satisfactory for one or more of the following reasons: l—insufficient stability of electrical properties with time, 2—poor reproducibility of electrical characteristics from melt to melt, 3—excessive temperature coefficients of resistance, and 4—excessive cost. Weston introduced the Cu-Mn-Fe and Cu-Mn-Ni-Fe alloys of the type now generally known as manganins. His patents are believed to represent the first disclosure of any alloy with a negative temperature coefficient of resistance. After this work, the German company, Isabellenhutte, in conjunction with Feussner and St. Lindeck, produced alloys of

Jan 1, 1957