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By Henry M. Howe

PART I. § 1. Introduction. After giving certain definitions, this paper gives the reasons which led to Roozeboom's form of the diagram of the freezing-point curves and general equilibrium of the iron-carbon compounds, steel and cast-iron ; and then those which led to replacing it with the present or double diagram, in which graphite is at all temperatures held to be the more stable and cementite the less stable (metastable) form of carbon. Next in § 10 the evidence supporting this greater stability of graphite is examined, then in § 17 that which seems to oppose it, and in § 22 a summary of the evidence is presented. The second part of the paper considers the topography of the graphite-iron diagram, rejecting summarily the solubility-lines based on the data of Charpy and Grenet and of Mannes-mann, on the ground that the data even on their face do not really point toward these lines, and that they are wholly incompetent to determine any solubility-lines whatsoever, because they report together with the dissolved carbon also an indeterminate quantity of cement-carbon, and because even such carbon as is actually dissolved, only in part represents the solubility of graphite, and in another and indeterminate part represents the solubility of cementite, or at least of carbon in presence of cementite as distinguished from graphite. It might be thought that graphite is but slightly soluble in iron, because of the absence of any suggestions of eutectoid graphite, corresponding to the eutectoid cementite of pearlite in very many cases in which the cast-iron seems to consist of ferrite and massive graphite only, and because of the micrographs of Goerens and Gutowsky. In these the primary austenite of cast-iron quenched but little below the eutectic freezing-

Jan 7, 1908

By J. Parke Channing

THE growth of and profession depends on meeting and solving new problems. It is a continuous process. 'A period free from new, or hitherto unknown, questions will be a period of arrested development in the profession it affects. The present generation has witnessed a' mechanical development that has been truly marvelous: Almost every day marks the advent of a new, or the improvement of an old; process, method or machine. Wonders are now commonplace. The impossible is regularly accomplished. Yet, with all our progress in every realm of science and with our development in the engineering field, advances which have made possible the marvelous growth in industry, we have not made commensurate gains in methods affecting the human factor. Without the cooperation of the worker, we shall always fall short of our goal in a mechanical or statistical sense. If we do not make the individual members of the human family strong, healthy, happy, and ambitious for better things for themselves and their children, we will have failed utterly, for that is the real reason for our existence as men and the purpose of our organized effort as an engineering group. Thomas A. Edison

Jan 1, 1921

Jan 1, 1951

Jan 1, 1951

Jan 1, 1967

By F. C. Langenberg, J. Chipman

Jan 1, 1959

By Paul R. Dingess, Edward H. Hare, Douglas C. Brockie

Mining in the Tri-State district of Missouri, Kansas, and Oklahoma has been nearly continuous from about 1848 until the present day, although the major activity was from about 1880 to 1955. The district, which has produced over $2 billion in zinc and lead concentrates, ranks as one of the greatest mining districts in the world. Unlike other Mississippi Valleytype deposits in the United States, which occur in Cambrian and Ordovician limestones and dolomites, the Tri-State district ores occur in Mississippian limestones containing abundant chert. Zinc is 5 to 6 times more abundant than lead. In the Picher Field, the principal sub-district which has accounted for 61 percent of the total district production, most of the ore has been mined from the single horizon, M bed. Most ore bodies, other than those of the "Sheet Ground" or blanket-type, are in large, essentially flat-lying breccia zones and have a definite mineral zonal pattern. An irregular, generally elongated central dolomitic core is surrounded progressively outward by the main ore run, the jasperoid zone, the muddy or shaly and bouldery zone, the sparry calcite limestone zone, and the fossiliferous, dominantly crinoidal, limestone zone. Some of the zones may be absent or nearly so and may overlap to some extent with an adjacent zone. Although the district has been studied by many authors, much controversy still exists about such items as genesis, paragenesis, and time of emplacement. These subjects are discussed in the paper.

Jan 1, 1968

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Jan 1, 1938

By F. G. Miller, E. B. Wilson

In 1972, coal mine productivity was in steady decline and labor and maintenance costs were spiralling upward. Yet, despite this sad state of affairs, nowhere in the US at that time was there a comprehensive and coordinated coal research and development plan in the offing. The Bureau of Mines had not yet been charged with such a responsibility, and industry was content to rely on machinery manufacturers for innovations. It was during this period that Bethlehem Steel Corp. determined that a new approach to coal mining research was needed for the industry as well as for the company itself. After studying Bethlehem's own mining practices, the state-of-the-art of mining research elsewhere, and development work by manufacturers, a comprehensive research package was presented to company management in late 1972. The ideas and experience of many operating and management personnel in the company contributed to the formulation of the final plan as approved.

Jan 10, 1976

By R. W. Stahl

Employees and dollars are necessary to all enterprises and any force, such as fire, which destroys either, can bring very serious consequences, including business failure. Since everyone acknowledges the necessity of conserving human life, we will devote most of our paper to the economic factors involved. A coal-mine fire is considerably more difficult to combat than a fire in a surface building because of the combustible surroundings in the mine, the explosive gases emitted from the coal, the suspension of explosive dust when mine timbers burn and the unsupported roof falls, the limited space in which approach to the fire can be made, and the limited avenues of escape. A survey of coal-mine-fire protection indicated that a rather low value was being placed on property and equipment. This prompted comparison with other industries. The comments made in this comparison are not intended as an indictment of the coal industry, since we do have mines that are well protected against fire, but the comments on conditions at the mines visited are factual and may help others to improve similar conditions. SURVEY PROCEDURES Plants of the steel, aluminum, rubber, chemical, and petroleum industries were surveyed, and all facets of the fire-protection scheme were covered. The industrial plant invariably had four times as much water readily available for instant use than the mine. In many mines where water is available, no equipment for applying it is provided, such as hose, nozzles, and adapters, so that time is lost in collecting this equipment. (See Table I.) EXTINGUISHERS Many more and generally larger portable extinpishers are available at the plant as compared to the mine. The extinguishers are generally placed nearer to sources of danger. In addition, respiratory protective equipment is always available at strategic points in plants but only in a few mines. (See Figs. 1 and Table 11) INSPECTING AND TESTING EQUIPMENT Plant water facilities are checked weekly and flushed at 6-month intervals, and hose is pressure-tested at least yearly; some mines check water yearly, but hose is not tested unless used. Fire extinguishers are inspected weekly in plants and completely overhauled yearly; one mine had monthly checks and overhauls only after use. FIRE BRIGADES AND TRAINING Every plant had designated fire-fighters and some complete full-time brigades; at one mine a chief mechanic was designated as being in charge of fires, and other depended entirely upon officials who might not be familiar with the equipment. COST OF FIRES AND PERCENTAGE OF CAPITAL INVESTMENT IN FIRE PROTECTION The direct cost of recent mine fires ranged from $128,000 to $240,000; indirect costs, such as lost tonnage, idled equipment, lost orders, and the like might run the cost to over $500,000. (See Figs. 2 and 3).

Jan 1, 1961

By E. D. Gardner

AGAIN in 1945, the fourth year of World War 11, the American mining industry met the necessary demand made upon it for metals. Lack of labor prevented full production in some districts; maximum output, however, was maintained with the man power available. Development work and maintenance of mechanical equipment were neglected in favor of immediate production. Drafting of the younger men continued throughout the year, and the loss of personnel to war industries with higher wage rates continued up to "V-J" Day, Aug. 14. Labor shortages were more critical in 1945 than in 1944 though the man-power situation eased for some districts in the last quarter of the year. The trend in mining for the most part was to increase tons per man-shift by continued increased mechanization and refinements in methods and practices; larger equipment was installed where practicable. Labor shortages, together with the current higher wage rates, have advanced mechanization several years ahead of normal progress. The manpower shortage and the employment of inexperienced men had the effect of decreasing the average efficiency of the individual workman, but this condition was largely balanced by improved organization, greater efforts to improve labor relationship, and increased use of incentive pay systems. Safety instruction was emphasized, personnel contacts were increased, and more frequent foremen meetings were held to clarify contract agreements. Many of the large companies maintained schools to train green workmen.

Jan 1, 1946

CAPTAIN JOHN H. BALLAMY John H. Ballamy, Captain on the Regimental Staff of the 103d Engineers, was killed near Fismes, on August 9, 1918. Captain Ballamy was born at Plymouth, Pa., in 1886 and graduated from the High School of that town in 1903. In the following year he began work as a coal miner, and at the same time began the study of mining engineering in the evening and any other spare time. He continued this diligent and energetic practice for many years. For sixteen years he continued in the employment of the Delaware, Lackawanna & Western Railroad Company's coal mining department, first as a practical miner, next as rodman on the survey corps, of which he soon became chief, then draftsman and mining engineer in the company's office. In January, 1916, he was promoted to the position of district engineer in charge of mining engineering work. He became a member of this Institute in September, 1917. CAPTAIN JOHN H BALLAMY. Captain Ballamy's military experience began at the same time as his engineering practice. He was a charter member of Company A, Engineers, N. G. P., which was organized ten years ago. He saw service on the Mexican border as First Lieutenant of this Company, and remained in that position until November, 1916. In July, 1917, he was again called into service and was sent to Camp Hancock, Ga., with the 103d Regiment of Engineers. Before joining this regiment he attended a school for officers at Fort Sill, Okla., where he received special training in field fortifications. In December, 1917, he was commissioned Topographical Captain on the Regimental Staff, and in April, 1918, preceded his regiment by about six weeks to France, where he again attended an officers' training school. He rejoined his regiment on July 15, near Chateau Thierry and was killed near Fismes on August 9, 1918.

Jan 11, 1918

By A. W. Fahrenwald

Flotation practice in Idaho is now about 13 years old. The advance has been steady during these 113 years. The operators have been alert to take advantage of the newest developments and they have themselves made a constant effort to improve their work. The metallurgical improvements are due to the development of (1) better equipment, (2) better reagents, and (3) better understanding and control of the process. During the eight years the writer has been in this district, there has been continuous experimentation by several companies to improve the ore dressing by flotation methods. Gravity concentration has fought hard to hold its place, and although it is true that gravity processes have been improved during this period, nevertheless, in several of the important mills of the district the few tables that managed to hang on have finally given way. On the straight-lead ores, tables and jigs are still used; and, due to better classification, their hold on this job has been strengthened. Ores of the District The ores of the district are of two general classes: (1) clean lead ores, such as those from the Bunker Hill and Hecla mines, and (2) complex lead-zinc ores. The general impression prevails that the clean lead ores, class 1, are simple and that it is easy to obtain high recoveries and good grade products. This, in a way, is a false impression; there is quite a high percentage of locked middling in these ores at 100 and' 150-mesh sizes. Improved classification preparatory to table treatment of this type of ore has made it possible to segregate effectively a high-grade middling which is further comminuted and floated. The complex lead-zinc ores of the district, of which the ore from the Morning mine of the Federal Mining & Smelting Co. is a typical example, always have presented a difficult problem. It always has been comparatively easy to make a clean lead concentrate, but it never has been possible to concentrate sphalerite with a specific gravity of 4.10 from siderite of gravity 3.88. Also, a large percentage of the galena and sphalerite of this class of ore refuses to separate out until the crushing has been carried

Jan 1, 1928

By H. H. Stout

In the early fall of 1925, the writer was conducting, in the Ledoux and Co. laboratory, New York, experiments directed toward ascertaining the effect on its impurity content when cathode copper was subjected to a current of various gases at an elevated temperature below the melting point. The apparatus consisted of a vertical I-in. dia. silica tube about 12 in. long, heated on the outside. The cathodes were broken to pass 3/8-in. mesh, and a current of various different gases was passed up through a 4-in. long column of these loose cathode particles in the vertical tube furnace. Temperature was maintained to 1500º to 1600ºF. and the gas treatments lasted from 3 to 6 hr. The writer observed that whenever reducing gas (H2 or CO) was used, these cathode particles stuck together at points of contact with each other. The cohesion was so marked and tenacious that an examination was made of the fractured surfaces, when cathode particles were broken from the cluster. Crystal growth was always found to have taken place across the surfaces where separate particles were in contact, but only after all oxides, sulphates, etc., had been completely removed. The idea of a possible new process was then conceived and was disclosed to A. M. Smoot (V. P. Ledoux and Co.) with intent to obtain his views. The first conception as given Smoot was "to gas-clean broken cathodes, put them in an extrusion press, solidify and extrude them at around 1500ºF." Smoot's reaction, after a few moments considera- tion, was, "It looks perfectly all right to me.'' The writer and his assistants, W. H. Osborn and H. H. Stout, Jr., after conferring as to ways and means, decided to go ahead with preliminary laboratory experiments, which, it was thought, would move the new process from the possible to the probable. This program followed a course indicated by three basic considerations: 1. Since brittle cathodes were often unintentionally produced, it seemed probable that the laws controlling this type of deposition could be ascertained. 2. We had already proved the gas-cleaning feature. 3. There remained to prove: whether a sound, homogeneous metal billet could be produced with crystal growth established over the entire surface of each individual particle in the billet; and, if so, what would be the physical properties? Osborn arranged with Columbia University for conducting experiments in its research laboratory to prove or disprove the third item; Columbia assigned C. A. Phillipi, Jr. to assist in the project. A press with a cylinder 2 in. high and of I-in. dia. was used. It was surrouilded and heated by a resistance coil 01 Nichrome wire. Broken tough cathodes were used. Experimental Procedure The first run took place March 18, 1926. The resistance wire gave out when temperature of 1000ºF. was obtained. Pressure was immediately applied: perceptible ram movement stopped when 39,000 lb. per sq. in. on the copper was reached, with a maxi-

Jan 1, 1941

By C. J. Bauer

WHEN the pipe lines from the Middle East to the Mediterranean are completed, the Middle East supplies will relieve the strain on Western Hemisphere petroleum resources, part of which are now shipped for Eastern Hemisphere use. A sketch of the world petroleum situation as it appears today and in the immediate future will help in understanding the future place of Middle East oil supplies. Anticipated 1951 world demand is slightly under four billion barrels. To meet this requirement, crude output and refinery runs throughout the world (including Russia) must be increased about two million barrels per day above the average of 1947. This increment, together with pipe lines, tankers, and other facilities, will require in excess of ten billion dollars of new capital in the next four years. We are, therefore, looking forward to the greatest expansion program in the history of the industry.

Jan 1, 1948

By C. A. Fisher

THE discovery of petroleum in Pennsylvania in 1859 marked the birth of an industry of paramount importance. Spreading from - Oil Creek, this remarkable industry may be said to have embraced the earth in a little more than half a century. Those who made the discovery little realized its deep significance or far reaching influence on our national life. For over sixty years, during which time this nation has created and developed the oil industry to a high state of efficiency and' carried its activities to all parts of the world, we have' at all times been the leaders in the production of crude oil and in the development of its technology. During the unprecedented growth and expanse of the oil industry there has been an increasing dependency of our basic industries on, petroleum, until at present it has become essential to our national existence. To meet the ever increasing demand for petroleum and its products, we have explored, at one time or another, for their oil possibilities, practically all parts of the sedimentary rock area in the United States. Furthermore, detailed surface and, in many places, subsurface studies have been made of all the promising regions; over 640,000 jewells have 'been drilled for. oil since the beginning of the industry; $12,000,000,000 have been spent in this work; seventeen major fields exceeding 100,000 bbl. daily production and more than a thousand minor pools have been opened up, and 8,000,000,000 bbl. 'of oil have been produced, or an amount nearly equal to the estimated future reserves of the United States made in 1921.

Jan 1, 1925

By E. H. T. Whitten

Fundamental principles of trend surface analysis are briefly reviewed. Recent analyses of several granite masses illustrate the method of estimating the quantitative regional composition and also variation trends. Mineralogi-cal, bulk chemical, and other quantitative variates can be employed. Such results should improve gravimetric surveys (etc.) relying on correction terms based upon estimated rock composition. For the first time realistic estimates of the mean composition of rock bodies can be made with the aid of trend components. Deviation maps hold promise for delimitation of disseminated mineralized areas. Deviations comprise residual "anomalies" after removal of trend components. In petrogenetic work such deviations have been shown to reflect local influences (e.g., contamination of magma by assimilation of xenoliths or country rocks of the envelope). Similarly, mineralization should be reflected as deviations standing out from background trends. Actual examples are given. Present results largely involved projection of data onto a horizontal plane, but if sufficient data are available use of three spatial coordinates increases accuracy for prediction in "unexposed" areas. Regression analysis shows that statistical correlations between variates for regionally distributed specimens are often strong (particularly with percentage data). Hence, in preliminary surveys more easily determined variates may sometimes be employed to gain first estimates of the distribution of components more economically significant. The sampling plan is of paramount importance. Unless a suitable sampling plan is devised and adhered to rigorously during collection of the samples, all subsequent analysis is liable to strong bias and to yield spurious estimates of the truth. For a wide variety of purposes it is becoming necessary to assess the quantitative composition and variability of rock masses and mineralized zones of various types. In petrology and petrography this is something of a break with tradition, because virtually all descriptions heretofore have been qualitative. Although vast amounts of qualitative data have been compiled, little is known about the quantitative behavior of rock components. However, if variability of rocks could be understood and expressed with sufficient accuracy, there would be considerable advantage to both economic and petrogenetic problems. For example, if, on the basis of a limited series of observations, the three-dimensional geometry of a disseminated orebody (or ore-bearing formation) could be predicted accurately, it would be possible to extrapolate with confidence the structure into unexposed areas. The following example based upon the geometry of an igneous cone sheet illustrates the point. The significant rock-unit gives outcrops at a number of points on the exposed surface ABCD (Fig. 1A). Study of n exposures may enable a geologist to predict that the rock-unit is circular in form and thus indicate where the unit can be expected in unexposed terrain. Such observations are made at sites with u, v coordinates, but, if subsurface information is available at sites with uvw coordinates, it will eventually become possible to predict accurately the three-dimensional form of the rock mass. Geologic rock masses or mineral deposits are not generally as regular and symmetrical in geometric form as the body illustrated in Fig. 1A. However, even where the broad limits of a major rock mass are known, a more acute problem arises in attempting to obtain detailed quantitative estimates of its internal variability; it is difficult to predict the variability of a mass from a limited number of observa-

Jan 1, 1961

By E. J. Roberts

Hydrometallurgical operations and many processes in the chemical industry require the separation of dissolved material from solids. One of the decisions which has to be made in designing a plant for such an operation is how this separation shall be accomplished. It is the purpose of this paper to set forth the general principles involved in such separations in order that the optimum flowsheet and equipment may be selected. Countercurrent Decantation with thickeners, or C.C.D. as it is generally known, is, of course, only one way of separating dissolved material from undis-solved. Other unit operations such as Countercurrent Filtration (C.C.F.) and Countercurrent Classification (C.C.C.) are widely used. The same principles may also be applied to centrifugally assisted decantation, as with nozzle or solid bowl type centrifugals, and to separations using screens, either gravity or centrifugal type. Another form of countercurrent washing applicable to granular materials is practiced in continuous ion exchange operations. All of these operations depend on two basic principles, or combinations of these principles. In C.C.D. type operations the solids are concentrated into the smallest possible volume of liquor in each step and the resulting pulp then mixed with a more dilute liquor and recon cen trated, the liquors separated from the more dilute stages being advanced to dilute the more concentrated liquor in a previous solids concentrate, as is shown in Fig. I. This will be termed the solids concentration-solution dilution principle, or, for short, solution dilution. countercurrent decantation- type circuits. The second principle used in washing solubles from solids is that of solids concentration-solution displacement. Here the solids are restrained from movement while wash solution is forced through the interstices in a counter-current fashion, as in Fig. 2. In the simplest application of this principle, once the "cake" has been formed, it is not disturbed until the operation is completed. In continuous filters, the cake is merely moved under the successive washes and the displaced filtrates removed as in Fig. 4. Often, however, after one or two displacement washes, a repulping step is introduced, the cake reformed and washed again. This procedure brings the solution dilution principle into play as well as the solution displacement principle. Merely thickening ahead of filtration, which is often operationally advantageous, does not hybridize he circuit. It still can be a pure solution displacement operation from the washing

Jan 1, 1961

By Byron Johnston

IN 1926 I had occasion to make numerous measure-ments with a Pitot tube. The differential gage was mounted in a box, and since the work entailed setting upon girders, staging, and flues of various shapes and slopes, much time was generally expended in getting the box blocked into the level position. This inconvenience was so considerable that I devised the gage stand shown in the accompanying illustration. The gage is bolted to the board seat, the bolt per-mitting unlimited adjustment in the plane of the paper. The seat, carrying the gage, revolves on trunnions, per-mitting unlimited adjustment in a second plane, per-pendicular to the first. Consequently, the stand may be stood up, hung by one corner, leaned against some-thing or simply laid down, and the gage levelled from any position. On uneven surfaces, where the stand naturally rests on only three of its legs, it may be swung in the manner peculiar to the tripod, bringing the center of gravity within the triangle formed by the legs, thereby providing a firm set-up. Rubber stoppers under compression were found to give sufficient friction to hold the seat in the desired position.

Jan 3, 1928

By J. J. Carrigan

IN all mining operations a considerable portion of the work performed, especially underground; is accomplished under artificial light, yeti this subject is often not given proper attention. Poor illumination decreases mining efficiency, impairs the sorting or grading of ores, and increases the risk of accidents. In the beginning, and for several years afterward in the metal-mining industry of Butte, Montana, candles placed in candlesticks were carried by the men. Sconces or holders for candles were also provided at stations and curves in drifts to furnish better light for men engaged in. hand tramming. It was also common practice to place clusters of candles on the ground, with no provision for guarding against an underground fire other than the exercise of sufficient care by the men themselves. An accumulation of candle grease from this source was the direct result of the first serious fire in the Anaconda mine, in 1889.

Jan 1, 1936