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A. M. CANDY,* Pittsburgh, Pa.-According to the tables on page 532, the deposit obtained with Roebling cold-rolled steel, and Toucan electrodes contained considerably less carbon and manganese than the original electrodes; whereas very little carbon is lost in the case of the hot-rolled steel electrode. When using the hot-rolled steel electrodes, the metal apparently has a tendency, probably due to greater surface tension, to pass through the arc in larger particles than the other electrode materials. This affords greater protection against oxidation, and thereby prevents much loss of carbon. The larger globules tend to increase the arc fluctuations due to greater partial short-circuiting of the arc. Actual oscillographic records show that with the hot-rolled steel electrodes the current peaks were 70 per cent. above normal whereas the peaks for the other electrodes were only about 25 per cent. -above normal. Probably due to the larger globules, a greater proportion of slag in the electrode was carried into the weld. Some four or five test pieces made with the hot-rolled steel electrodes were all considerably below the tensile strength of the samples welded with the other electrodes. These facts indicate that an electrode may not be satisfactory even though of approximately the proper chemical composition. For example; the hot-rolled steel and Roebling electrodes are quite similar in chemical analysis.

Jan 4, 1919

By R. F. Frantz, T. P. McNulty

The upper-level mineralization of the din Buttes, Arizona copper orebody consists primarily of dilute copper silicate impregnation in fault clay and throughout the altered limestone hostrock. Cuprite and native copper are minor with true chrysocolla rare. Owing to the high calcium carbonate and to the hydrogen ion exchange capacity of the clays, acid leaching would be economical only with cheap acid available. Leaching of the silicate copper with reagents other than sulfuric acid is slow and incomplete unless the ore is first heated to disorder the mineralized grains and to reduce partially the contained copper. Following heat treatment, 70 to 90 percent of the nonsulfide copper can be dissolved in aqueous anrmonium carbonate. Recovery of a pregnant solution by counter-current decantation is effective provided ammonium carbonate solution is added to the washing stages in order to oppose adsorption of dissolved copper by clays in the residue. Thermal stripping of the pregnant solution permits recovery of ammonia and carbon dioxide while precipitating copper either as oxide or carbonate. The research program was carried from batch tests through continuous miniplant operation to a five-month campaign in a 20 TPD continuous pilot plant. Pilot plant results, the relationships among key varibles, and a detailed flowsheet are given.

Jan 1, 1973

By Charles J. Haas

The effectiveness of rock bolts in resisting shear displacement along preexisting fracture surfaces or slip planes was determined in the laboratory with full-scale bolts and large-scale shear test equipment. The system variables were the type of bolt, orientation of bolt relative to shear surface, and normal pressure on the interface. Results showed that, in general, both conventional bolts and resin- grouted reinforcing bars significantly increase the shear resistance along a fracture or bedding plane when the average normal compressive stress on the plane is in the order of 25 psi and when the bolt is oriented such that it tends to lengthen as the shear progresses. An increase in shear resistance is also noted at the higher normal pressure of 250 psi; however, the increase is small compared to the corresponding shear resistance without a bolt. Conventional bolts oriented such that they lose tension as shear displacement occurs added no shear resistance since the tension drops to zero at very small shear displacements.

Jan 1, 1977

By Clarence Hicks

THE labor policy, of the Standard Oil Co. (New Jersey) is founded. first of all on paying at least the prevailing scale of wages in the community; on, the eight-hour day, with time and one-half for overtime; one day's rest in seven; sanitary and up-to-date working conditions; just treatment assured each employee; payment of accident benefits beyond the amount prescribed by the State compensation law; health supervision by a competent medical staff; payment of sickness benefits after one year's service; cooperation with employee in promoting thrift and better social and housing conditions; and assurance for a generous annuity at the age of 65, guaranteed for life after 20 years of service. Most of these features have been a part of the company's policy for many years, but it is only during the past two years that the cooperation of employees in determining these matters has been definitely assured through industrial representation. Industrial representation, in the Standard Oil Co., is a principle rather than a procedure. It is built upon the belief that personal association of those interested in any problem leads to a mutual understanding and a fair decision as to what is right. Fully believing in this, principle, representatives of employees and representatives of management evolved a simple plan, the basis of which is that it gives every individual employee representation at joint conferences on problems and fundamental principles affecting all those interested in the industry. It is based on cooperation, not antagonism; its operation makes perfectly clear both to management and to employees that their interests are identical, that mutual understanding and cooperation insure progress and success for all. Furthermore, experience has definitely shown that representatives of the employees are not only alert for the employees' interests but are as keen as the representatives of the management in determining and insisting upon fairness to the employer.

Jan 3, 1920

By J. W. Pugh, Sam Leber

Single crystals of tungsten were made and deformed in tension at 3000°C. The slip traces so formed on these crystals were analysed to determine the apparent slip system. Results indicate that deformation occurs in the<III> direction on planes of maximum shear stress. This determination agrees with the early work of Taylor and Elam on other body-centered cubic crystals at lout temperatures. SLIP in face-centered cubic and hexagonal close-packed metals has consistently manifested itself in straight traces which indicate that glide takes place on planes of highest atomic density and in directions of closest packing. The slip traces observed on body-centered cubic metals are, on the other hand, frequently branched and wavy, and indicate that while glide takes place in the direction of closest packing, it does not necessarily choose the plane of highest density. The early work of Taylor and Elam1 4 indicated that glide took place in the close-packed direction on planes close to those defined by the maximum shear stress. Subsequent investigations have tried to rationalize these observations in terms of an elementary process on the close-packed planes (110). For example, Elam5 and Grenin~er&apos; have suggested alternate glide on nonparallel (110) planes with the observed result that the summation of these glides results in a trace which defines some plane other than{110). Madden and chen7 have recently reviewed the phenomenological and theoretical aspects of noncrystallographic slip. More recently Koehler&apos; has presented a model of dislocation propagation which permits another rationalization. He indicated that dislocation loops are transferred from one glide plane to another by double cross-slip of screw segments. It is reasonable to assume that, on the average, such transfers may result in a trace which approaches the plane of maximum shear stress. The work described in this paper will show that

Jan 1, 1961

By E. C. Rien

When the electrical system for a surface or open pit mine is designed, four major considerations should be satisfied in the following order: safety, reliability, flexibility, and cost. Careful planning initially will make expansion for future growth economical as well as possible without extended shutdown of operations. Electrical requirements in surface and open pit mining can be divided into three categories: main substation, plant power, and pit distribution. These systems are integral to each other, but will be dealt with separately here. 11.2-1. Main Substation. A main substation for a mining operation may vary from a 500 kva transformer supplying 480-v power to motor-driven pumps and conveyors, to a 50,000 kva substation serving a large beneficiation plant or a large strip mining operation. Regardless of size, it should be designed with the realization that a failure of the main substation will totally shut down the operation (Fig. 11.2-1.). Location of a main substation usually is a compromise between expense of running the incoming high-voltage transmission lines and the voltage drop of long secondary runs. Based on a geological survey for immediate and future areas of excavation, the main substation should be located as near to the center of load as possible. The site should be out of the blasting area, readily accessible to authorized personnel, and situated where prevailing winds will keep it free from dust or snow. DISCONNECTS AND OVERLOAD PROTECTION. The main substation should have a primary disconnecting device-either a pole top gang-operated switch and fuses of adequate interrupting capacity or, preferably, an oil circuit breaker with properly coordinated relay protection.

Jan 1, 1968

By John Pew

PRIOR to the development of the bulk-oil carrier, practically all transportation of oil was in barrels and in cans contained in wooden cases; the latter was known as case oil. In the year 1885, approximately two hundred million gallons of petroleum were exported from this country in barrels and about one and three-quarter millions in bulk; less than twelve years later, the shipment in barrels had decreased to nearly one and three-quarter million gallons, while the transport of bulk oil had increased to four hundred eighty-four million gallons. The first modern tanker, the "Glückauf," was built in England in 1886. Her hull, which was 300 ft. long, was divided into compartments by transverse bulk-heads, these compartments being divided by longitu-dinal center-line bulkheads extending throughout the oil spaces. There was a pump room forward of the boiler room, thus providing a cofferdam or safety space. Between the main and upper decks, a narrow trunk extended the full length of the&apos; oil spaces, the trans-verse and longitudinal bulkheads being carried to the upper deck. This allowed for the expansion of the oil from a rise in temperature, and if the tank below the main deck was kept full, the danger of the oil moving with the roll and pitch of the vessel was considerably reduced. Spaces for the carriage of light oil were provided on each side of the vessel outboard of the expansion trunk, while water ballast was carried under the machinery compartments fore and aft. Although vessels previously had been built to carry oil next to the skin of the ship, it is claimed that the "Glückauf" was the first one constructed on the new principle outlined.

Jan 12, 1922

The Library of the above-named Societies is open from 9 A.M. to 10 P.M. on all week days, except holidays, from September 1 to June 30, and from 9 A.M. to 6 P.M. during July and August. The Library contains about 55,000 volumes, including sets of technical periodicals and the publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library can render valuable service through correspondence; letters requesting information will receive special attention. The Library is prepared to furnish references and copies of articles on mining and metallurgical subjects; to determine the existence of mining maps, and to furnish general information as to the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The, time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape. The members of the Institute can be of service to the Library by forwarding copies of mining reports, maps privately issued,-,and similar material, which will be classified, indexed, and made available to other members. Suggestions for additions to the Library, either by purchase or personal solicitation as gifts, will be welcomed. It is hoped that members while in the city will use the Library freely, and assurance is given that most careful service will be rendered to them.

Jan 5, 1914

By James Harding

THE usual method of sampling mineral deposits is to drill holes and assay the sludge or core. Though the results thus obtained may not represent the true average value of the deposit, it is on these results that estimates of practically all large orebodies are made. In a large number of cases, the results of exploitation fall far short of the estimated value of the orebody. The standard method of making these estimates is to find the cubic contents of triangular prisms, in the apexes of which the drill holes are placed, .by multiplying the surface area by the average depth of the ore in the three drill holes and then multiplying the cubic contents by the specific gravity of the ore or rock to find the tonnage. The assay value is found by dividing the sum of the products of the depth of ore in each hole and the corresponding assay value by the sum of the depths of the ore in the three holes. As the latter part of this method is subject to many mathematical errors, it should not be depended on.. Some engineers, therefore, use a discount factor, but as this factor is either arbitrarily selected or is obtained by obscure methods, the results are no better than guesswork. The standard method is correct when the drill holes are so laid out that the triangular prisms are equilateral in cross-section. But as ore deposits cannot always be drilled into at regular intervals and because of the human factor, if many holes are drilled, triangular prisms of all degrees of angularity are produced. In such cases, it is necessary to assume that the influence of the different holes is not the same in all directions, which assumption of course is absurd.

Jan 1, 1921

By Henry Howe

(New York Meeting, October, 1913.) The Equilibrium. Position of A 1.-Some of the most important data on this subject are collected in Table I. Definition of Ae 1-Just as we call A 1 of rising temperature Ac 1, and that of falling temperature Ar 1, so we may give the symbol Ae 1 to the equilibrium position of A 1. Preliminary Assumptions.-In deciding what weight to assign the various data, and indeed what data are to count, three assumptions should be made. These are: 1. The corollary from the phase rule, that the temperature of Ae 1 is constant and independent of the carbon content, though, of course, it may be changed by the presence of other elements. 2. That because neither in heating nor in cooling can the transformation begin before the temperature reaches Ae 1, though it may be delayed by lag till after the temperature has passed beyond Ae 1, therefore Ae 1 should be at or below the observed beginning of Ac 1 and at or above the observed beginning of Ar 1, and, a fortiori, it should be at or below the observed maximum of Ac 1, and at or above the observed maximum of Ar 1. It may be necessary to take these maxima into consideration in view of the experimental difficulty of detecting these beginnings.

Jan 6, 1913

By Charles Willis

THE time is no longer when a man can act as an independent unit; the appreciation of the interdependence of one man upon another has emphasized the importance of the social unit. Epidemics have made us recognize that even a man&apos;s health is not distinctly his own to control as he pleases. The physical examination of workmen previous to employment started with an effort to prevent the spread of tuberculosis, for tuberculosis may be .detected in its early stages and cured. But it was soon found that many other diseases were detected and the saving of lives made possible. The physical examination does not mean the elimination of the unfit-on that basis it would utterly fail- but rather the measuring of a man&apos;s physical fitness and placing the man where he can do the best for himself, his fellow worker, and the company. Industry as a whole cannot expect to live up to the standard of physical examination set for the army, nor should it expect to do so, for in all branches of industry there are types of work that do not require -the same amount of endurance as does army work, and the placing of men with physical limitations in the work for which they are&apos; capable permits a higher average of physical fitness for the work requiring physical excellence.

Jan 7, 1919

By Walter Miller

The focus of attention during 1939 was on increasing the octane number of gasoline. The "octane race" resumed full swing. The averagc octane number of house-brand gasoline by the end of the year had easily reached two numbers higher, with several companies in the field actually purveying house-brand gasoline of 78-80 "research" octane number, equivalent roughly to from 74 to 77 A.S.T.M. octane rating, compared with the 70 A.S.T.M. ceiling of two or more years ago. Whether this trend toward much higher octanes is the result or the cause of the many t,echnical developments in the motor-fuel field of recent, years, progress has really been startling. In addition to the advance in catalytic cracking and catalytic re-forming, other important contributions to the technical ability to produce higher octane values include: installat>ions involving increased capacity in thermal re-forming, with improved economic status both as to yields and octane number, by coupling with catalytic polymerization; more widespread adoption of catalytic and thermal polymerization, and a surge toward extensive installations of newly developed alkylation processes for making iso-octane, neo-hexanr and other high antiknock products; and greater use of improved desul-phurization processes, and application of superfractionation methods for segregation of practically pure hydrocarbons with superior octanr qualities from gas and highly volatilc liquids. The approaching of practical limits in the use. of tetracthyl lead (t,hr well-known "law of diminishing returnsn coming into the picture at the higher octane levels being approached) has given impetus to development of the methods listed above. In particular, processes that improve the octane rating and also increase ethyl lcad sc.nsitivity have had considerable study durirlg the year. CatSlytic Re-foRming Although the interesting report on the Houdry catalytic cracking process presented at the annual meeting of the American Petroleum

Jan 1, 1940

By E. R. Parker, E. A. Smith

Metallurgists and engineers have always been interested in the mechanism of high-speed deformation because metals are rapidly deformed in various applica-tions and manufacturing processes. The deformation of metals by impact loads has recently engaged the attention of a number of investigators. Many of their results have not been disclosed but some of the published investigations1-8 have shown that the tensile strength, yield strength and elongation generally increase with increasing strain rate. The investigation reported herein is an attempt to determine the reason for this increase in strength and elongation. found to depend upon the strain rate. In the bars broken at high speeds, the slip bands appear to be more numerous. This might account for the higher strength as well as the greater elongation. Experimental Procedure Single crystals of copper (approximately 99.98 per cent) were made in graphite molds by the conventional method of lowering the mold out of the hot zone of a hydrogen furnace at a rate of one inch per hour. Solidification progressed from the bottom upward, forming a single crystal. The crystals were about 0.30 in. in diameter and 4 in. long. They were

Jan 1, 1944

FRIENDS of the late Charles F. Rand presented in 1930 a sum of money from which the income is available to support various phases of the work of the Institute in which Mr. Rand was so deeply interested. At present the fund amounts to $10,000. The specific terms of the deed of gift are as follows: "The fund collected to establish a memorial to the late Charles F. Rand shall be placed in the custody of the Board of Directors of the American Institute of Mining and Metallurgical Engineers, to be set up as a trust to be known as the `Charles F. Rand Foundation,&apos; the income of which shall each year be applied to a distinct purpose to be decided upon in that year by vote of the Board of Directors. This purpose shall be such as to promote the general welfare of the Institute and to constitute a permanent memorial of the usefulness of Mr. Rand, who for many years gave unstintingly of his time and talents in its service.

Jan 1, 1946

By H. D. Hoskold

As the theory and the practice of valuing mines have never been discussed in the Transactions, a paper on the subject may be acceptable, even though not exhaustive. The method here indicated is set forth, not as a model of perfection to be followed absolutely, to the exclusion of any other system based on sound scientific, commercial and equitable principles, but merely as an aid to mining engineers and financiers in estimating the value of mining-property. This paper is intended merely to point out certain financial features of the question, and not at all to go into the theories of the formation of mineral veins, extremely valuable as it must, of course, be to understand the laws of the earth&apos;s formation and of its various changes, which are the basis of such important sciences as geology and mineralogy, and highly useful as guides in determining the probable existence and extension of mineral deposits. Financial Elements of Mine- Valuation. The practice of basing the stock-exchange price of mining shares upon reports, periodically received from the mine-captain or manager, stating that in his opinion the mine is " improving " in this or that level, and is worth so much " per fathom," is, of course, absurd. Everybody experienced in metalliferous mining is aware that a mineral vein varies in thickness and also in percentage of metal in different parts of the same mine. According to the practice just indicated, a mine must have had as many values a per fathom " as there have been given reports upon it at intervals during the year,

Jan 1, 1903

By Dwain K. Butler

INTRODUCTION Characterization of a site for the prediction and simulation of dynamic events requires the determination of mechanical properties of the rock at stress/strain levels and rates and at a scale appropriate for the events and critical structures involved. The structures of interest can be on the surface, underground, or designed to impact and penetrate into the site (projectiles). Dynamic events of interest are equally diverse: seismic waves from distance earthquakes or explosions; close-in phenomena associated with earthquakes and explosions; vibrations associated with heavy equipment or machinery; and stress transients associated with impact and penetration. The complexity of site characterization depends on two factors not specifically related to the nature of the site itself: the stress levels generated by the dynamic event and the sophistication of the prediction and simulation techniques. For very high stress levels, such as occur near a nuclear detonation, and for low stress levels, such as occur during seismic wave propagation, site characterization is simplified, and often certain details of the site are not particularly important, such as shear strength variations in the case of very high stress levels. In the intermediate stress range, however, all descriptive relations are non- linear, a complete finite strain constitutive model is required, and all details of the site, such as lithology and fracture distribution, become important. The site characterization must be complete enough to support the most sophisticated prediction and simulation technique that will be applied to the analysis of the dynamic event. The procedures of site characterization are illustrated in this paper by a specific dynamic event, projectile impact and penetration, and a specific site, an outcrop of Dakota Sandstone near San Ysidro, New Mexico. The structure of interest was the projectile itself: nominally, 1.5 m in length, 0.165 m in diameter, 180 kg

Jan 1, 1984

LATEST estimates of Russian steel production for 1951 give rise to the belief that on at least one vital front, the Western bloc of nations has maintained a definite advantage. On the surface, we are outproducing the Eastern bloc by more than twice. The United Nations Economic Commission for Europe estimates Russian output at 31.30 million tons, a 15 pct increase over the previous year. Production for the entire Iron Curtain is figured at 40.93 million tons. Western Europe alone produced 17 pct. more steel during the same period. The figures are misleading in one sense. We have no precise idea of how much steel is being used for arms. The Western nations are still expending much of their production for consumer goods, and you cant throw washing machines in a shooting war. It is significant to note that Russian production is well, beyond estimates made by world authorities prior to the current international situation. INTERIOR Secretary Oscar L. Chapman warns that the United States must make use of the resources of other nations or face mineral impoverishment once the time of struggle is over. He pointed out that the present struggle between two ideologies can leave the United States in such a state as to preclude anything but political&apos; victory-with an accomp anying economic loss that will be irreparable. Chapman scored the attitude whereby conservation programs are looked upon as a luxury, pointing out that the nation faces an ever increasing need for action on that front. He also announced that the Bureau of Mines doubled its facilities for producing pure zirconium during 1950-51 at the request of the Atomic Energy Commission. Zirconium may be an important structural metal for atomic power devices. The Interior Secretary also said that the AEC has provided the Bureau with funds for the study of radioactive minerals and to help test and evaluate about 9000 ore samples believed to contain uranium.

Jan 1, 1952

By J. B. Umpleby

The subject of reservoir energy and its efficient utilization has been well explored in many papers. The present effort, therefore, is limited to a summary of existing information combined with an emphasis of the probability that the relative importance of controlling factors will change with advancing knowledge. Consequently the necessity for flexibility in laws and regulations, inherent in the problem, is emphasized. Definitions Many terms have been widely used in the literature without having been specifically defined. For example, confusion exists in the use of ((reservoir energy" and "gas energy." The latter is much more limited in meaning than the former. Other terms have been variously used. Consequently, I shall preface my remarks with definitions of a few of the more pertinent terms. Reservoir energy is that force or forces, active or potential, that is native to the reservoir and has the power to move oil through the reservoir rock. The energy may result from expanding gas, from hydrostatic head, from the weight of overburden, or from any other source. Gas energy is the expansive power of gas when pressure is reduced. It is one type of reservoir energy. An oil reservoir is that part of a geologic formation or formations in which oil occurs in commercial quantities wholly surrounded by nonproductive rock. The essence of this definition is effective separation rather than remoteness and under it oil reservoirs may be superimposed in the same oil pool. Conservation of reservoir energy means primarily its maximum use in the production of oil. Unit operation is a plan of development and production, which embraces an entire oil reservoir under a unity of engineering control. It is distinct from unitization, which has to do with arrangements of organization and equities to make unit operation possible in areas of divided ownership.

Jan 1, 1934

For the past several years the policy of a large section of our mining industry in relation to our present bureaucratic form of government has become increasingly amusing, if not a little disgusting. In the past, mining men have always featured themselves the self-announced champions of free enterprise, and, generally, this conviction, was substantiated by their deeds. In recent years, however, a large group of the industry, while still expounding, from the front porch, the principles of free enterprise and a sound economy based upon the law of supply and demand, have gone around to the back door with palm extended, to join labor, farmers, bureaucrats, and other pressure groups to get their share of the take. The procurement of subsidies, bonuses, increased metal prices, and government assistance in a multitude of forms seems to have obscured from their thinking the welfare of the country as a whole and the sounder economic principles of a balanced budget and lower taxes. At the recent Colorado Mining Association convention in Denver, I. was alarmed to see just how far this specialinterest type of thinking has progressed within the mining industry. Government assistance to mining. was generally considered inadequate, and a flat bonus for any new mineral discovery was proposed. It was disquieting, too, to learn how far the federal alphabet agencies have entered into the mining industry and of the thousands of highly paid technical. men on the federal payroll required to man these numerous overlapping agencies and bureaus. Now all this is very fine, and some aspects of the federal give-away program can be very appealing to the unsuspecting in the mining industry as they have been to those in other groups. Some of these expensive programs may bring about a few dividends or even several new mines. But to this whole line of pump-priming reasoning there is one big disastrous fallacy.

Jan 1, 1952

By William Metcalf

ONE of the first questions that naturally occurs to one who handles steel is," Why does steel harden ?" To answer this question the chemist and physicist have devoted much thought and experiment, and while they have enriched our store of knowledge of the nature and composition of steel, it cannot be said that they have yet solved the problem involved in its hardening. In this communication I desire to direct attention to a line of investigation yet new, in the hope that it may receive the attention of those who have the time and ability to pursue it. I refer to magnetism. There are so many parallels between the action of magnetism on iron and steel and their behavior under different processes of manipulation that it would seem as if there must be some connection between the forces at work in the different cases, if, indeed, there be not an identity of force in all of these cases. Magnetism, as we know it, may be merely the visible manifestation of forces, which may serve as a guide to lead us to an exact knowledge of the structure, the strains, and the resistances with which we have to deal in iron and steel. If a magnet be brought close to a pile of iron filings, the little pieces of iron will fly to the magnet and attach themselves to it, with their longer axes lying in the direction of the force. If molten cast iron be poured into an iron mould,-a chill,-the iron upon crystallizing will form needlelike crystals, with their long axes normal to the surfaces of the mould. If the iron is at the proper temperature and the quantity small, compared to the mass of the mould, the whole of it will be chilled, or set, in&apos; the hard needlelike crystals

Jan 1, 1881