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By Frank Foote

IN recent years the constitution of the high-silver aluminum-silver alloys has been extensively investigated. Hansen1 has re-viewed the literature to 1935. More re-ently, Obinata and Hagiya,2 Hofmann and Volk,3 Taziri4 and Tishchenko5 have con-firmed the general features of the phase diagram in the region around 25 atomic per cent aluminum. In this paper we present the results of high-precision measurements of lattice con-stants of the silver-rich alpha solid solution in the homogeneous range and the neigh-boring two-phase regions. These results are used to establish the nature of the solid solution, the identity of directly measured densities with those calculated from lattice constants and the homogeneity limits of the alpha solid solution with respect to three different neighboring phases. A study of the earlier investigations indicated that the last two subjects in particular required new and accurate data.

Jan 1, 1940

TWO hundred enthusiastic engineers and coal, op-erators attended a joint meeting of the A. I. M. E., the National Coal Association, and the American So-ciety of Mechanical Engineers in the auditorium of the Alabama Power Co. building at Birmingham, Ala., on Jan. 21. S. W. Farnham, mining engineer of the Goodman Manufacturing Co., Chicago, in his paper on mechanical loading of coal discussed the feasibility of scraper and machine loading. A. R. Anderson of the Jeffrey Manufacturing Co., in a paper on loading coal with conveyors covered their adaptation for long-wall mining and for loading into cars. Discussion of these papers was hampered because the cheap labor costs prevailing in the district have handicapped gen-eral mechanization of the mines. The Bureau of Mines film, "The Story of a Rock-dusted Mine," showing the New Orient mine, West Frankfort, Ill., was also shown at the meeting. F. H. Crockard, president of the Wood-ward Iron Co., represented the A. I. M. E., S. L. Yerkes, vice-president of the Grider Coal Sales Agency, and J. L. Davidson, secretary of the Alabama Mining Institute, represented the National Coal Association, and Paul Wright represented the American Society of Mechan-ical Engineers.

Jan 2, 1927

Jan 1, 1957

By James W. Malcomson

The Tigre Mining Co. of Mexico, owned by the Lucky Tiger Combination Gold Mining Co. of Kansas City, decided early in 1910 to enlarge its mill, which consisted of a concentrator milling 3,000 tons of ore per month. The enlarged plant was designed to crush and concentrate 6,000 of ore and to cyanide 7,500 tons per month. The extra tonnage cyanided was to be obtained from tailings which were stored below the old mill. Power was supplied to the old mill from four boilers; a 150-h-p. Corliss engine and two Weber 60-h-p. gas-engines using producer-gas made from charcoal. The total horse-power required, including 60 h-p. used for machine-drills in the mine, was approximately 275. Cord-wood cost $4.32 per cord, 8 by 4 by 3 ft., and charcoal $15 per ton. The fuel supply in the surrounding country was approaching exhaustion; more than 150 mules and 50 men were engaged in cutting and transporting this fuel, and the unsettled political conditions in Sonora were such that it would be practically impossible to keep an organization of this kind together. The price of fuel was steadily rising and at times it became almost impossible to get sufficient fuel to operate. It was estimated that the enlarged plant, together with the mine, would require 750 h-p., as follows: Horse-Power. Old mill, which was left unchanged,..............180 New concentrator,.......................90 Cyanide-plant,........................380 Mine and other requirements,................. 100 Total,........•..................750 In a study of the best manner to obtain power the following alternative propositions were considered:

Jan 1, 1914

By S. G. Bankoff

INCE1 proposed that electrostatic attraction between oppositely charged particles was responsible for slime-coating. Del Giudice2 postulated the metathetic formation of a cementing compound. Wark3 suggested that prevention of slime-coating was related to peptization of the slime. [ ] In the experiments of Table I the technique employed was essentially that of del Giudice, with the difference that the particle was examined under a film of water rather than dry.4 In general, the polished particle was agitated for 2 min. in a pulp consisting of 12.5 grams of the slime (-200 mesh) and 50 c.c. of distilled water, washed in three baths of distilled water, and examined at 220 diameters with the Leitz Ultropak. Observations of Brownian movement were made at 850 diameters with dark-field illumination. Several of these experiments do not jibe with the metathesis theory. According to published solubilities,5,6 the lead salts of the anions in experiments [c] through g are more insoluble than lead carbonate, therefore should prevent the formation of lead carbonate on the galena surface. In experiment [i] the calcium oxalate, which presumably was on the calcite surfaces, should have permitted the formation of a lead carbonate cement by virtue of its greater solubility. Experiments [j] through m show that the addition of lime accelerates the deposition of quartz onto a galena surface. The writer is unable to postulate a satisfactory cementing compound, according to the metathesis theory, to explain this effect. These experiments led to the conclusion that the metathetic formation of a cement-

Jan 1, 1941

By Harlan A. Walker

ROCK-DRILL steel has an important bearing on costs in many mining operations, both directly and indirectly. Direct factors include such items as shop expense, steel consumed per ton of ore produced, cost of distribution and the dust hazard. The latter, although no specific amount may be assigned to it, is an ever-present problem, and is receiving increased attention as the science of mining progresses. Indirectly drill-steel performance affects consumption of compressed air, maintenance of drills and drilling speed. The latter, in turn, increases or retards the tempo of mining and development. These factors, while not all inclusive, are preponderant in their importance. Thus it is evident that in an extensive operation drill-steel expense may run to many thousands of dollars and that thoughtful research leading toward more efficient practice is warranted. EXPERIMENTAL WORK During the late spring of 1939, experiments were undertaken at Homestake in reducing changes in drill-steel gauge from 1/8 in. to 1/16 in. [ ] In drifts and crosscut headings mounted machines were set up and holes were drilled with 1/8-in. bit-gauge changes and other holes a few inches

Jan 1, 1940

By Frank C. Greene

The wildcatting in northern and northwestern Missouri, which started in 1939, was continued in 1940. Two new gas fields were found and one discovered in 1939 was further extended. The total number of completions was 94, of which 5 were oil wells with about 48 bbl. initial production, 30 were gas wells with an initial open-flow capacity of 37,655,000 cu. ft., and 59 were dry holes. The outstanding discovery was the Polo gas field, T. 55 N., R. 28 and 29 W., in Caldwell County. A sand now believed to be a lens in the Bandera shale at a depth of 400 ft. yielded flows of more than 12,000,-000 cu. ft. In all, I0 wells with 31,490,000 cu. ft. of gas, were drilled. The rock pres-sure is 80 lb. At present no arrangements for an outlet have been made. In Platte County, the Prairie Point gas pool in sec. 7, T. 51 N., R. 33 W., and sec. 12, T. 51 N., R. 34 W., and the Lake-side pool in sees. 5 and 6, T. 50 N., R. 33 W., were further developed, and in the latter both oil and gas have been found, but data are not available for publication at this time. Drilling for gas continued in proven areas in Clay County, and for both oil and gas in proven areas in Jackson and Cass Counties. Table 1 summarizes the results of drilling in Missouri in 1940.

Jan 1, 1941

By R. W. Prouty

THE methods of sampling and ore estimating used at the Copper Queen Branch, Phelps Dodge Corpn., as applied to the Copper Queen mines at Bisbee, Ariz., fall into two divisions because of the difference in occurrence, manner of prospecting, and methods of mining: that for the underground operations and that for the Sacramento Hill steam-shovel operations. The orebodies of the Warren district may be divided into three classes: Replacements of limestone, replace-ments of porphyry, and replacements of contact breccia The first class is more or less intimately related to porphyry intrusions, although in badly fractured country this relationship may not be well shown. These orebodies are mainly oxide and carbonate ore and very irregular, both in size and outline, although usually roughly lenticular and following the bedding of the limestones. There is usually quite a sharp boundary between the ore and waste in the carbonate and oxide orebodies and sampling is not necessary to determine the limits of commercial ore. In the sulfide orebodies it is exceedingly difficult, without sampling, to deter-mine the boundary between commercial ore and the surrounding low-grade or barren pyrite. Calculations made a few years ago showed that these orebodies had an average thickness of 35 ft. As some of the ore-bodies have a thickness of from 100 to 300 ft., it can be seen that the smaller ones form a difficult problem both in prospecting and in estimating.

Jan 11, 1922

By W. J. Nelson, R. B. Nance

Detailed underground geologic mapping at a scale of 1:1200 has been carried out at the Crown II Mine of Freeman United Coal Mining Co., which operates in the Herrin (No. 6) Coal Member. The roof sequence, upward from the coal, includes (1) soft, medium -to dark-gray shale; (2) hard, black, fissile shale; (3) argillaceous nodular- bedded limestone, and (4) fine-pined, shaly, water-bearing sandstone. The first unit is highly lenticular, and any or all may be missing at a given locality. The sandstone has a sheet facies and a channel facies. The Herrin Coal is eroded in channels near the Crown II Mine. Structural features mapped at Crown II include normal and strike-slip faults and limestone "bosses." Less stable roof and wet conditions are encountered where the limestone is thin or missing or where it is broken by natural fractures or by artificial openings that intersect the water-bearing strata above the limestone. Geologic mapping of the underground workings has allowed us to predict faults, fracture zones, and channels ahead of the face for this mine. Some lithologic and structural pattern apparently are random and cannot now be projected. Conventional exploratory drilling is entirely inadequate to map faults or lithology of the roof, but it does indicate the range of lithologic variability, which can be used to project needs for roof supports. Drilling also is useful in locating channels and in mapping regional variation in thickness and facies of the sandstone.

Jan 1, 1983

By L. C. Uren, E. J. Bradshaw

This paper presents the results of a group effort by a number of University of California students and faculty members, and the authors attach their names primarily in the capacity of editors and interpreters of the data thus assembled. In addition to the writers, the following individuals have made substantial contributions in time and effort in the conduct of this research: Dr. A. J. Carlson, Associate Professor of Petroleum Engineering; J. E. Gosline, University Research Assistant; C. F. Bedford, G. W. Mikulasek and H. S. Conder, senior and graduate petroleum engineering students; H. Bachman, G. Spencer and G. W. Gard, mechanicians in the Department of Mining and Metallurgy. Acknowledgment is also due the Research Board of the University, the Department of Mining and Metallurgy, and Prof. F. H. Probert, Dean of the College of Mining, for continued cooperation in securing mechanical assistance and funds for the purchase and assembly of apparatus. Significance of the Pressure Gradient The expulsion of petroleum from its reservoir sand doubtless is due to expanding natural gas intimately associated with the oil, to the hydrostatic pressure of encroaching edge waters, and to gravitational influences. These forces may operate independently or collectively. In any case they subject the fluids stored within the reservoir sands to elevated pressures, thus causing movement of oil and gas through the productive formations toward the lower pressure of the well outlets. This movement is opposed by pore friction, capillarity and adhesion: resisting influences brought to bear by the reservoir sand on the moving fluids. The magnitude of the resisting force is influenced directly by the viscosity, surface tension and density of the oil, as well as by the properties of the gas. The more rapid the rate of flow, the greater will be the resistance offered, and the greater will be the energy consumed.

Jan 1, 1932

By Otto H. Henry, Edward L. Badwick

Up to the present time, according to Hansen1 and Haughton,2 the constitution of the bismuth-indium system has not yet been published. The generally accepted value for the melting point of indium, as listed in most scientific journals and textbooks, is 155°C. Recently, however, H. M. Davis3 has determined a new melting point for indium of 257.3°C ± 0.1°C. Since bismuth has been used in preponderance as an alloying element in the majority of low-melting alloys, and indium has been used with considerable success in lowering the melting points of low-melting alloys,4,5 an interest has been developed in the application of these two metals, making a complete knowledge of the constitution of its alloys desirable. In this investigation, the melting point of indium reported by H. M. Davis has been found to be substantially correct. A value of 157.2°C ± 0.5°C was determined. The two eutectic compositions have been placed at 34 and 50 pct bismuth with their respective eutectic temperatures as 72.4'C ± 0.5°C and 90°C ± 0.5°C. The bismuth-indium phase diagram has been determined by thermal and microscopic analysis and is shown in Fig I. THERMAL ANALYSIS Granulated bismuth and indium shot, having a guaranteed purity of 99.99 and 99.95 pct, respectively, were melted in a carbon crucible by means of a laboratory heater. To minimize oxidation of the alloys, a heavy mineral oil (Nujol) having a high flash point was used. A platinum-platinum rhodium thermocouple 0f fine wire encased in a thin-walled Pyrex glass tube, about 1/8 in. in diameter, was connected to a type K potentiometer for temperature measurements. The thermo-couple was calibrated against the melting points of tin, bismuth, and the silver-copper eutectic and the boiling point of water. Since the temperature readings could be reproduced to 0.2°C, and the accuracy of the temperature standards in this range is slightly better than 0.5°C, it seems reasonable to assume that the temperature readings are reliable to approximately 0.5°C. The cooling rate could be controlled by varying the amount of insulation surrounding the crucible. Three or four layers of asbestos paper, 1/16r, in. thick, sufficed to give a cooling rate of from 1° to 2°C per minute. Undercooling was slightly noticeable. This condition was minimized by vigorous stirring, since the advantage of using slower rates was too small to justify the greater expenditure

Jan 1, 1947

By W. L. Kendrick

Jan 1, 1957

By Richard P. Rothwell

THE communication which I have to lay before my fellow-members of the Institute, is no elaborate paper, nor the statement of any great discovery ; it is simply the record of convenient methods of conducting topographical surveys, and of keeping the notes of the same; methods that have grown out of practical experience, and have saved me many a day's labor by facilitating office and field work, and at the same time secured a greater degree of accuracy than is obtained by the methods now in general use. I assume it as granted that no topographical map is worthy of the name, except it represent the elevations and depressions of the surface by means of horizontal or contour lines. In the Ordnance Survey of Great Britain, the contour lines are traced for every fifty feet vertical height, I believe, by running out the line with level and compass through all its meanderings on the surface ; this, of course, is a very tedious, though accurate process, but "in the woods," where many of our surveys have to be made, it would be practically impossible. Some time ago, I made an extensive and quite elaborate topographical survey and contour map of the southern portion of the Cahaba coal-field, in Alabama, the object of the survey being to

Jan 1, 1875

The Institute conducts jointly with the American Society of Civil Engineers, American Society of Mechanical Engineers and American Institute of Electrical Engineers, certain activities as listed below, and is joint owner with them of certain properties. United Engineering Trustees, Inc. When Mr. Carnegie made his gift which made possible a home for the engineering societies, a separate corporation was organized to act as a holding company and to manage the common property. This was long known as the United Engineering Society, but the name has now been changed to one which more nearly reflects the real function of the corporation. It holds title to the Engineering Societies Building and to various funds placed in its charge and is managed by a Board of Trustees, of which three are chosen by each of the four societies, American Institute of Mining and Metallurgical Engineers, American Society of Mechanical Engineers, American Institute of Electrical Engineers and American Society of Civil Engineers, which have equal and undivided interests in the property. The land and building cost two million dollars. The interest of the Founders societies, aside from especial trust funds, is now valued at $1,987,793. The A. I. M. E. trustees are William H. Bassett, H. G. Moulton and R. M. Roosevelt. The President of the Board is Harold V. Coes and the Secretary, Alfred D. Flinn.

Jan 1, 1934

By Oliver U. Bradley

The conditions affecting the supply of casinghead gas, the different degrees of productivity, the difficulty of determining the quantities utilized, and the evaluation of the gas in casinghead-gasoline units and related data, having an economic bearing on the industry as a whole, are important questions and offer an interesting field for study. Casinghead-gas data have been gathered in some of the oil fields of Oklahoma where testing work has been done regularly and the volumes of casinghead gas were available. The area covered embraces 219 scattered leases in 29 townships, with a total of 18,039 acres and 1921 wells. The accompanying table gives specific locations of the areas under consideration, number of leases, range depth of wells, average age of production, sand depths and oil production data. The results of this investigation are set forth in the accompanying charts, showing volumes of casinghead gas in 6-month periods from Jan. 1, 1918, to June 30, 1921, when full record was available, production of casinghead gasoline, average productivity of the gas in gallons per thousand cubic feet, average price of the gas and the market price of the casinghead gasoline. The cases enumerated in the table and the data shown in the graphs do not represent the greater part of oil or casinghead gas production from any one township, nor are the leases contiguous. The properties in each township, however, may be considered as typical of general conditions, such as the date of completion of wells, depth, character, and thickness of oil sand, time of pumping, present oil production, Vacuum carried on wells, and usual operating practices. It was deemed advisable to subdivide the time into 6-mo. periods, as it was impracticable to make the tests more frequently, furthermore 6 mo. is probably the minimum period within which there would occur a noticeable increase in the productivity of the gas. It must be remembered that the figures on volumes are subject to the usual irregularities and relative inaccuracies of meter measurenlents of gas under varying degrees

Jan 1, 1924

By O. P. Arora, M. Metzger, G. R. Ramagopal

The rates of grain boundary and general corrosion were surveyed by an approximate method. Quantitative differences between their variations with the strength or cupric ion content of the acid yielded large variations in their ratio, highly selective intergranular attack being observed only under specific chemical conditions. The boundary corrosion rate increased with the copper content of the aluminum; this was attributed to an autocatalytic effect similar to the one shown for general corrosion. High- purity aluminum in hydrochloric acid exhibits striking intergranular corrosion and other structure-dependent corrosion phenomena of fundamental interest. The behavior is highly sensitive to the metallurgical and chemical conditions, the significance of many of which has not been established. The features of the intergranular-corrosion phenomenon, first described by Rohrman,l are summarized in the remainder of this paragraph. Strong attack normally occurs only at high-angle grain boundaries.' Usually 15 to 25 pctHCl is used to obtain a high rate, but this has also been obtained with weaker (7 to 15 pct) acid either by adding cupric or ferric ion to the acid3-5 or by passing an anodic current (-0.1 ma per sq cm).2,3,5,6 The two latter corrosion conditions produce strong attack of low-angle boundaries after certain heat treatments 2-4,5,7 The susceptibility of high-angle boundaries is influenced by the grain-boundary segregation of iron atoms; this increases the slow (µ per month) attack in 10 pct HCl8 but diminishes the rapid (mm per month) attack in 20 pct Hc14 (the present and most previous investigations deal with rapid attack). That segregation of elements other than iron affects intergranular corrosion has not been demonstrated, although analysis of data for iron alloys indicated that at least one other element must be considered.9 Intergranular attack occurs over a wide range of purity although it begins to become obscured above several hundred parts per million (ppm) total im- purities by the severe general corrosion which accompanies the higher iron contents and which is associated with the presence of a second phase or an inhomogeneous distribution of the dissolved iron.4,6,10 The variation of intergranular-corrosion rate with heat treatment1'3-6'"10 can be explained in some cases in terms of the distribution of the iron impurity but is not in general adequately understood. The present work dealt with two questions not previously considered in detail. The first proceeded from the view that the extent to which a special behavior is associated with the boundaries is indicated not by the intergranular corrosion rate alone but by the ratio of the intergranular to the general corrosion rate. A comparison of the two rates was therefore made for one lot of aluminum in acids of varying strength and metallic ion content. The second question was the effect of the copper content of the aluminum. For general corrosion, it has long been known that copper ions introduced into the acid by corrosion of the solid solution are reduced on the aluminum as patches of elemental copper which enhance the corrosion rate by providing cathodes of lower hydrogen overvoltage than were originally present.''-'3 Since the copper patches remain themselves unchanged, their action is "catalytic", and since they are products of corrosion, the effect is "autocatalytic." This phenomenon is significant at copper levels much lower than previously suspected, even at those typical of high-purity aluminum, as the authors have shown in a previous paper.l4 The present work shows that copper content affects intergranular corrosion. With polycrystalline specimens, truly quantitative rate measurernents are not readily made for intergranular corrosion or for general corrosion in the presence of rapid intergranular attack, and previous work in this field has tended to be qualitative. The present study made use of a simple procedure which provided fair approximations to the quantitative corrosion rates and fitted the purpose of surveying the behavior over % wide range of conditions and displaying certain large effects. The approximations involved in this work were usually outweighed by the experimental scatter, which tends to be substantial in a system as sensitive as this one. I) EXPERIMENTAL A. Material. The material procured, Table I, represented three low copper (1 to 3 ppm) lots, two of "normal" copper content (21 and 22 ppm), and two

Jan 1, 1962

By David M. Hopstock

The performance of the most common type of low-intensity dry magnetic separator is analyzed on the basis of fundamental physical principles. Expressions are developed for estimating the optimal choice of design and operating parameters for beneficiation of magnetite ores. By proper choice of these parameters either a high-grade concentrate or a low-grade tailing can be produced from an incompletely liberated feed.

Jan 1, 1976

ARSENIC and orpiment are two mineral substances of a similar kind, and they are by nature pure, without admixture of other species. In regard to their apparent qualities we shall say that their composition is scorched, well-purified earth; and because of a certain subtlety and easy digestion they penetrate very easily into fused metals, indeed they act in such a way that they corrupt and convert almost into another nature any metal with which they find themselves. Orpiment and arsenic act in almost the same way as do tin and mercury. With these the fraudulent alchemists blanch copper, brass, and even lead to the whiteness of silver. According to the physicians they are in fourth part hot and dry. They are also corrosive because of certain powers; indeed, they are a most powerful poison to the life of all things. Arsenic is found in white and citrine colors. Orpiment seems to be a separate thing, although both are formed in the same ore and both are in lamellae or scales. These lamellae or folds are thinner than paper, in fact

Jan 1, 1942

By John T. Grasso

This paper describes the computer-assisted development and implementation of new written examinations for persons desiring to become certified as underground or surface mine electricians in the State of West Virginia under the certification program defined by the WV Department of Mines and the Board of Miner Training, Education and Certification. The procedures used to develop and validate the new certification tests have simplified the administration of the new tests. Future developments in mine electrical work can also be easily incorporated into the certification program by augmenting the existing computerized pool of test questions prior to computer-production of future test forms. Most important, computerization now facilitates continual evaluation of the certification program, to contribute to greater safety in mine electrical work in West Virginia.

Jan 1, 1983

By Walter H. Ortel, George B. Wallace

INTRODUCTION A greater understanding is required about the factors which control tunneling operations if we are to meet the expected demand for tunnels. Much of the needed information can best be achieved by the proper use of instrumentation and advanced engineering concepts. Tunnel measurements and their analysis may prove to be the key which will give the insight necessary to understand the relationship of rock, tunnel supports, and linings. There are three main areas which can be improved through the use of tunnel instrumentation. First, and of prime importance, is safety for men and the project. When unstable conditions occur, sets become distorted. Even without measurements, it is sometimes possible to tell when trouble is approaching. In effect, the set acts as a load cell. Distortions in the set indicate reinforcements may be required to maintain stability. Additional sets or rock bolts, if they are placed soon enough, may provide this stability. However, when large rock displacements occur in short periods of time, it could be too late. Figure 1 is an example of the difficulties encountered in stopping moving rock. To stop the movement and possible failure, large props were placed above the spring line and the massive concrete gravity buttress was constructed along the legs. Rock bolts from the buttress deep into the rock were also used in an attempt to stabilize the rock mass. However, this work is for a highway tunnel and eventually these props and buttresses must be removed.

Jan 1, 1971