Search Documents

By J. Visman

FOR more than 25 years evaluations of coal cleaning units have appeared in many publications, and during this time considerable progress has been made in developing the theory and techniques of calculating washery results. A variety of characteristics have been defined over the years, many receiving general recognition during the first post-war Coal Preparation Conference in Paris in 1950. Coal preparation has become a science, and the approach to preparation problems is being revolutionized. Formerly, for example, if a coal operator wanted to know the performance of a given cleaning unit for a particular grade of his run-of-mine, he either shipped a carload to the manufacturer for a test run or relied on a report of a test carried out on a coal similar to the one he intended to clean. In modern practice the expensive, time-consuming test work generally can be avoided if the washability curves of the coal in question and the error curve of the cleaner are known. Normally a guarantee can be given on the strength of this information. General acceptance of modern standards has thus reduced the need for pilot-scale models of existing types of coal cleaners. Needless to say, the method requires exhaustive and accurate information on the cleaning unit and on all the additional circumstances affecting its results, in- formation that ultimately can be secured only from actual tests made in the laboratory or in the washery.

Jan 10, 1954

By Charles Fettke

IN THE present day manufacture of glass nearly pure quartz sands are used almost exclusively as the source of the silica, which is the major constituent of all common varieties of glass. Ordinary soda-lime, such as bottle, common tableware, plate, and window glasses, contain from 65 to 75 per cent. of silica. OCCURRENCE Glass sands occur in nature either in the form of loose, unconsolidated sediments or in deposits in which the individual grains have been more or less thoroughly bound together by some cementing agent so as to form sandstones. While deposits of sand and sandstones occur both widely and abundantly distributed, deposits that are sufficiently free from other constituents than quartz grains, so that they can be employed in the manufacture of the better grades of glass, are, comparatively speaking, of rare occurrence. The major portion of the glass sand produced in the United States comes from sandstones. In order to be suitable for glass sand, they should be rather friable. The rock should break down readily along the cementing material between the grains and should not break across the grains rather than along the bond. Some of the sandstones used are so friable that only light shots of slow-burning dynamite are necessary to disintegrate them sufficiently for hydraulic mining, while others have to be passed through crushers in order to disintegrate the rock into its individual grains.

Jan 2, 1926

The adoption of a plan of safeguarding American industry against extreme revolutionary industrial propaganda is the keynote of a report just issued by ex-Governor Robert P. Bass, of New Hampshire, covering the period of his service as. Director of the Marine and Dock Industrial Relations Division of the United States Shipping Board. He thinks that the only hope of America's resisting the tide of industrial unrest that is sweeping over the civilized world is in the development and early application of a constructive industrial program, in which program publicity and education carrried on by the Government will hold a leading place. He says: The Government should systematically inform both employers and employees in regard to many matters of the utmost interest and importance of each. It should acquaint labor with the Government's activities and service to labor in the past and should create in labor an appreciation of its joint interest with capital and with the Government in the problems of production. Satisfactory assurances should be given that labor will have a substantial voice in determining the distribution between capital and labor of the profits of production. Labor should be promised its reasonable share of any increase in production. There should be a joint determination of wages, hours, and conditions of work. Based on the foregoing principles, great emphasis should be placed on labor's interest and responsibility in the processes f production.

Jan 6, 1919

Raphael PUmpelly, who became a member of the Institute in 1871, the year of its organization, and retained his membership for a long period, died at his home in Newport, R. I., Aug. 10, 1923. He is survived by a son, Raphael, Jr., and by two daughters, one of whom is the wife of Prof. Henry L. Smyth, of Harvard. Doctor Pumpelly was born in Oswego, N. Y., in 1835. He studied sciences and mining engineering in Paris and at Freiberg, later taking his Doctor's degree at Princeton. He was Professor of Mining at Harvard from 1866 to 1873. Doctor Pumpelly made geological explorations in many lands. In 1861-63, he conducted a scientific exploration for the Japanese government, and for two years thereafter carried on researches in central, western, and northern China and Mongolia. In 1864-65, he undertook a voyage of exploration across the Gobi desert, returning to Europe through Siberia. He was State Geologist of Michigan from 1869 to 1871; Director of the Missouri Geological Survey from 1871 to 1873; and Chief of Division, U. S. Geological Survey, directing the mineral industries division of the tenth census. He organized and directed the Northern Transcontinental Survey, 1881-84; directed the explorations inaugurating the iron ore industry of most of the ranges of Michigan and Western Ontario, 1897-1901; initiated and directed a physical-geographical and archeo-logical exploration of Central Asia under the auspices of the Carnegie Institution of Washington, 19034.2.

Jan 1, 1924

By W. W. Coblentz

THE constants in question pertain to the total radiation and the spectral radiation of a uniformly heated enclosure, or so-called black body. These constants have been determined for the range within which temperatures can be measured with thermocouples. Conversely, using these constants and suitable instruments, such as an optical pyrometer, for example, it is possible to determine temperatures far above the range attainable with the most refractory thermocouples. The formula of Stefan Boltzmann for expressing the total radiation of a black body is R = kT4 in which k is the coefficient or "constant" under discussion. In view of the fact that total radiation pyrometers are usually calibrated on an arbitrary scale, there is no great demand for an exact value of the coefficient of total radiation in absolute value. However, it is intimately connected with the constant of spectral radiation; hence, an accurate determination of the constant k gives a check on the constant of spectral radiation. The distribution of radiation in the spectrum of a black body is represented by Planck's equation, E? = C1?-5 (e c/?T - 1)-'. The spectral radiation constant c, in this formula, is useful in optical pyrometry and in establishing a high temperature scale. The numerical value of the constant c has been determined in the range of temperatures measurable with thermocouples and, also, by extending the temperature scale to higher temperatures by means of total radiation measurements.

Jan 8, 1919

By Francis M. Walters, Irwin R. Kramer

The substitution of cobalt for part of the nickel in Invar was found by P. H. Brace1 to lower the coefficient 01 expansion. Scott1 extended the use of cobalt to alloys of higher inflection temperatures. Such alloys have a larger temperature range of low expansion than those without cobalt, and their use up to 400' or 500°C. offers decided advantages in certain applications. However, it has been found that the iron-nickel-cobalt alloys are not stable in this temperature range. Experimental Methods Two methods were used in studying the stability of the low-expansion iron -nickel-cobalt alloys. Dilatometer specimens were held at 480°C. for 9 months and the change in expansion characteristics was dctcr- mined. Filings were held for about 2 months at various temperatures and the change in structure was determined by X-ray diffraction. As shown by Table I, the alloys studied covered a wide range in nickel plus cobalt content (which determines the inflection temperature) as well as some variation in the ratio of nickel to iron (which controls the temperature of the gamma to alpha transformation). Included also are alloys containing carbon and vanadium, carbon and titanium and three with various amounts of copper. The alloys were melted in a high-frequency induction furnace with a magnesia crucible, using ingot iron, electrolytic nickel and commercial cobalt. Fifteen-pound heats were cast into iron molds after deoxidizing with silicon, or

Jan 1, 1942

By T. Sterry Hunt

I HAVE already referred to this interesting locality in the opening address, but at the request of some of the members of the Institute, brought before them specimens of the ore and the accompanying rock. The ore, which is cassiterite, is also met with elsewhere in Maine, at Paris and Hebron, but it there occurs associated with orthoclase, quartz, tourmaline, and beryl, in concretionary granite veins, which cut the micaceous gneisses of the White Mountain series. At Winslow the veins traverse an impure gray micaceous limestone, which is found in many parts of this region, and is subordinate to the same gneissic series. The veins, which are seldom more than an inch or two in thickness, are abundant through a considerable breadth of the rock, and are interlaminated with it, occupying places between the sedimentary layers, which are distinctly marked by different shades of color. Occasionally, however, they cut across the stratification for a little distance, showing that the disrupting action was not always confined to tearing the layers apart. The vein-stone consists of purple fluor-spar, and silvery white mica with quartz. In this gangue the cassiterite, nearly black in color, is disseminated in small crystalline masses, sometimes one-half an inch in diameter, and is associated with a little mispickel. I have only seen the veins as exposed at a single point, but was informed that similar veins holding the ore are met with at a distance of several thousand feet

By F. S. Peabody

ANYTHING that may be said about "too much coal" must seem rather incongruous just at this time when two-thirds of the mines in the United States have been idle for nearly four months and a temporary coal shortage looms as more and more of a possibility. It is the purpose of this article, however, to deal primarily with the fundamental ills of the bituminous-coal industry, which, when summed up, can be expressed in one word-overdevelopment. During recent years the bituminous-coal industry in the United States has been seldom, almost never, in a state of normal business health with production run-ning evenly, prices steady and the market absorbing the output from week to week. There has been either a condition of feverish activity or apathetic sluggish-ness. We have had, for example, the intense strain on production during the war years with heatless days and lightless nights, followed by the slump late in 1918 which lasted through the greater part of 1919 when coal was a drug on the market. Then came the panicky demand of 1920. Competitive buying forced prices up to the highest levels in history. This demand in turn fell off suddenly in November, 1920, and the market remained apparently paralyzed all through 1921. During the latter year, lack of buying forced intermit-tent suspension of mining in all fields and prices averaged less than actual cost of production.

Jan 8, 1922

By Persifor Frazer

During the Centennial year some of our leading geologists in the United States and Canada conceived the happy thought of calling an International Congress of Geologists for the purpose of agreeing upon such important though subsidiary matters as the colors by means of which the different geological formations should be expressed ; the terms that should be applied respectively to these formations; and also upon the far more important problem of the limits and values of these different formations. The first session of this Congress was held in Paris in 1878, the second session in Bologna in 1881, and the third session in Berlin in 1884. The third session found the preliminary difficulties so far cleared away that some definite and tangible results could be attained. After a great deal of free discussion had taken place at Paris and Bologna, during which every one's views were listened to with attention; and a great deal more painstaking scientific work had been accomplished by the International Committees, having before them the objects of unifying the nomenclature of the science, and of preparing a scheme of colors between the second and third sessions of the Congress; and after the provisional results had been subjected to a searching criticism by the Congress in Berlin; it was decided to make an attempt to embody these provisional results in some work which should include as many as possible of the difficulties to

Jan 1, 1887

By T. Sterry Hunt

I HAVE already referred to this interesting locality in the opening address, but at the request of some of the members of the Institute, brought before them specimens of the ore and the accompanying rock. The ore, which is cassiterite, is also met with elsewhere in Maine, at Paris and Hebron, but it there occurs associated with orthoclase, quartz, tourmaline, and beryl, in concretionary granite veins, which cut the micaceous gneisses of the White Mountain series. At Winslow the veins traverse an impure gray micaceous limestone, which is found in many parts of this region, and is subordinate to the same gneissic series. The veins, which are seldom more than an inch or two in thickness, are abundant through a considerable breadth of the rock, and are interlaminated with it, occupying places between the sedimentary layers, which are distinctly marked by different shades of color. Occasionally, however, they cut across the stratification for a little distance, showing that the disrupting action was not always confined to tearing the layers apart. The vein-stone consists of purple fluor-spar, and silvery white mica with quartz. In this gangue the cassiterite, nearly black in color, is disseminated in small crystalline masses, sometimes one-half an inch in diameter, and is associated with a little mispickel. I have only seen the veins as exposed at a single point, but was informed that similar veins holding the ore are met with at a distance of several thousand feet.

Jan 1, 1873

INTERNATIONAL GEOLOGICAL CONGRESS. (For further particulars apply to the Secretary, 12th International Geological Congress, Victoria Memorial Museum, Ottawa, Canada ; cable address, Geocong, Ottawa.) The Coal Resources of the World.-Three quarto volumes of about 400 pages each, 8 1/4 by 10 3/4 in., and an atlas of about 70 maps in colors, 13 1/3 by 19 1/2 in., bound in heavy paper cover. Edition limited to 3,000 copies, One thousand copies will be reserved for members of the International Geological Congress, and the remainder of the edition will be distributed in the order in which applications are received. Price, $35 per set. Ready in July, 1913. This book is an inquiry made upon the initiative of the Executive Committee of the Twelfth International Geological Congress, with the assistance of geological surveys and mining geologists of different countries, published by: Morang & Co., Ltd., Toronto, Canada. Headquarters During Session at Toronto. The headquarters will be a t the University of Toronto, where there will be a branch post-office open at all hours and at which registered mail may be received or despatched, money orders sent or cashed, etc. A hank will be established at which money may be exchanged. A typewriting service will be maintained, also a telephone service and messenger service. Railway and steamship agents will also be in attendance. A restaurant service providing luncheon in the middle of the day will be arranged.

Jan 8, 1913

By Francis M. Walters, Irwin R. Kramer

The substitution of cobalt for part of the nickel in Invar was found by P. H. Brace1 to lower the coefficient 01 expansion. Scott1 extended the use of cobalt to alloys of higher inflection temperatures. Such alloys have a larger temperature range of low expansion than those without cobalt, and their use up to 400' or 500°C. offers decided advantages in certain applications. However, it has been found that the iron-nickel-cobalt alloys are not stable in this temperature range. Experimental Methods Two methods were used in studying the stability of the low-expansion iron -nickel-cobalt alloys. Dilatometer specimens were held at 480°C. for 9 months and the change in expansion characteristics was dctcr- mined. Filings were held for about 2 months at various temperatures and the change in structure was determined by X-ray diffraction. As shown by Table I, the alloys studied covered a wide range in nickel plus cobalt content (which determines the inflection temperature) as well as some variation in the ratio of nickel to iron (which controls the temperature of the gamma to alpha transformation). Included also are alloys containing carbon and vanadium, carbon and titanium and three with various amounts of copper. The alloys were melted in a high-frequency induction furnace with a magnesia crucible, using ingot iron, electrolytic nickel and commercial cobalt. Fifteen-pound heats were cast into iron molds after deoxidizing with silicon, or

Jan 1, 1942

By Francis M. Walters, Irvin R. Kramer

THE substitution of cobalt for part of the nickel in Invar was found by P. H. Brace1 to lower the coefficient of expansion. Scott1 extended the use of cobalt to alloys of higher inflection temperatures. Such alloys have a larger temperature range of low expansion than those without cobalt, and [ ] their use up to 400° or 500°C. offers decided advantages in certain applications. However, it has been found that the iron-nickel-cobalt alloys are not stable in this temperature range. EXPERIMENTAL METHODS Two methods were used in studying the stability of the low-expansion iron-nickel-cobalt alloys. Dilatometer specimens were held at 480°C, for 9 months and the change in expansion characteristics was determined. Filings were held for about 2 months at various temperatures and the change in structure was determined by X-ray diffraction. As shown by Table I, the alloys studied covered a wide range in nickel plus cobalt content (which determines the inflection [ ] temperature) as well as some variation in the ratio of nickel to iron (which controls the temperature of the gamma to alpha transformation). Included also are alloys containing carbon and vanadium, carbon and titanium and three with various amounts of copper. The alloys were melted in a high-frequency induction furnace with a magnesia crucible, using ingot iron, electrolytic nickel and commercial cobalt. Fifteen-pound heats were cast into iron molds after deoxidizing with silicon, or

Jan 1, 1941

By R. S. Busk

A PREVIOUS paper1 has summarized the effect of A all metallic elements on the lattice parameters of magnesium. The present paper deals with the effect of temperature on the lattice parameters and the way in which that effect is modified by alloyed elements. The experimental techniques for sample preparation, exposure to the X-ray beam, measurement of line diameters, and calculation of the parameters were the same as reported in the previous paper. The temperature of the specimen was raised by surrounding the mounted compact with a conical Glas-Col,* the base of which was sealed with Saran film. In this way the temperature of the specimen could be raised to 200 °C, which was the maximum desired in the present study. Control of temperature was effected by maintaining a constant, desired voltage to the resistance coils of the Glas-Col through a Variac. Temperature was measured by an iron constantan thermocouple embedded in the body of the specimerl so that the thermocouple bead was within 1/16 in. of the surface exposed to the X-ray beam. Variation of temperature during an exposure was less than + 1/4 oF. A series of eight alloys, consisting of pure Mg, Mg+Ag, Mg+Al, and Mg+Sn were studied. All percentage values are in atomic percent. The results are given in Table I. The density values given in Table I were calculated from the lattice parameters, using an equation due to Foote and Jette:"

Jan 1, 1953

Karl L. Fetters moves to the front of the AIME organization this month as the 1964 President of the Institute. He will take the chair vacated by outgoing President Roger V. Pierce at the Annual Meeting in New York, already well-rehearsed in his forthcoming duties after a year of preparation as AIME President-Elect. Dr. Fetters is highly qualified for his new responsibilities on both the administrative and professional level. For the past five years, he has been vice president for research and development at The Youngstown Sheet and Tube Co. in Ohio, where he has achieved wide recognition as an out- standing metallurgist and executive. A native of Alliance, Ohio, he obtained his early education in the public schools of his home town and displayed a singular precocity when he launched his professional career as a chemist for the Morgan Engineering Co. at the age of 16. His new career, however, was soon set aside in favor of four years of higher education at the Carnegie Institute of Technology, whence he emerged in 1931 with a bachelor's degree in metallurgical engineering. Surprisingly, and perhaps owing to the employment stringencies of the Depression years, the first job his new qualifications earned him was that of stationary engineer at the Cunningham Sanitarium in Cleveland. After two years of ministering to the mechanical ailments of this institution, Dr. Fetters relinquished his post for a more suitable one in the field of metallurgy.

Jan 2, 1964

By Augustus Locke

Two Opposed Interpretations of the Tonopuh Structure.—The important geological publications concerning the Tonopah min-ing-district are those of Spurrl aud of Burgess.² In these publications are presented fundamental differences of interpretation, which are the more interesting because both authorities have had ample opportunity for observation, and because both are geologists of proved ability. I was vastly puzzled to know which had the better of it, and in order that I might reach a conclusion in my own mind, I recently spent some time in the district going over the physical evidence. Surprising as it may seem, this evidence looks conclusive. A review of it will, I believe, be of interest to those who are familiar with the previous publications. The general geological features of Tonopah are shown in Fig. 1, and the differences of interpretation referred to are outlined in the accompanying notes. Brieflyj Burgees regards the various rocks as flows, lying in the order of their deposition. Spurr regards them in part as flows, and in part as flat-lying intrusives. The disagreement, then, concerns the rocks regarded on the one hand as intrusives, and, on the other hand, as flows. These rocks are chiefly the so-called calcitic andesitc, the upper rhyolite, and the lower rhyolite. Economic Importance of the Question of Interpretation.—The economic importance of the question of interpretation is, of course, limited to its bearing on the probable distribution of

Jan 1, 1913

By Joe L. Ratigan

INTRODUCTION Rock mechanics engineers are seldom concerned with obtaining the tensile or fracture strength of brittle rock at low mean stresses. The reason for this is two fold. Firstly, the behavior of many excavations in brittle rock is controlled by the inherent discontinuities in the rock mass. Because of the jointing and faulting, tensile strength is usually taken to be negligible. The second reason that tensile strength is seldom obtained in the laboratory is that the technology of utilizing this strength measure in design is undeveloped. Despite the fact that tensile strength of brittle rock is often ignored, there are a number of applications in rock mechanics wherein the knowledge of tensile strength is of fundamental importance. The apparent tensile strength must be known in a hydraulic fracture experiment if the state of in situ stress is to be determined from the initiation of the hydraulically induced fracture. In certain underground situations, the apparent tensile strength of intact rock beams defined by jointing or bedding planes is important in determining required rock bolting. Numerous other situations require a knowledge of apparent tensile strength including such high technology uses of underground space as geothermal energy extraction and LPG storage. Three observations are invariably made when intact rock samples are taken into the laboratory and tested to determine tensile strength. (1) The apparent tensile strength depends on the sample size (the 1 arger the specimen, the lower the tensile strength)

Jan 1, 1982

By S. E. Bretherton

THIS title introduces the subject I wish to describe to my fellow members, very few of whom, I hope, have ever had as much trouble with the smelting of ore containing much zinc, either in the lead blast furnace or the matting furnace, its circumstances have forced upon me: First, for several years in Leadville, Colo., after the sulphide ores containing zinc had been developed with greater depth and were sold to the interests with which I was connected for smelting in the blast furnace for the recovery of the lead, silver, and gold; then, in New Mexico and Arizona, where the principal source of ore supply for our custom smelter was from miners who sent most of their product in the form of concentrates, which we briquetted and smelted in the blast. furnace, producing a matte containing copper, silver, and gold, for which we were paid; together with some zinc and lead, which was penalized if in excess of a maximum base set by the refinery to which we sold our copper matte; last, but not least, my experience in Shasta county, Cal., where for the sake of recovering $13 per ton value in copper, silver, and gold, I have smelted ore containing as high as 40 per cent. zinc (the last. 18,951 tons smelted averaged 15 3/10, per cent. zinc) which we not only lost, but which it cost us money to lose.

Jan 8, 1913

By Oswald J. Heinrich

This question having been repeatedly raised, and particularly revived in a discussion at the last meeting of the Institute, I beg to submit the following remarks, based partly upon personal experience, partly upon the results of large works in Europe, establishing, years ago, the practicability of certain methods, which may therefore be considered to have passed the stage of mere experiment. Before entering upon the merits of one system or the other, it is indispensable to lay down some recognized principles, which ought to serve as guides, in arriving at fair judgments in questions of this character. In a profession like that of mining, locally so much influenced by combinations of circumstances too various to mention, it is difficult to do more than lay down the main features of a system based upon general laws and recognized facts, leaving the details to the sound judgment and experience of the engineer, who, by virtue of his education, ought to be able to make such choice and such modifications in the plans of a mine as the particular case demands. Mineral resources, in some countries the sole property of the owner of the soil, in others controlled by the strong hand of a government, are nevertheless a gift of nature, in which, indirectly, the whole of the human race has as real an interest as the immediate owner himself. This interest requires, at least, that no unnecessary waste of

For the first time in its history the Institute will hold a meeting in the State of Arizona. A few years ago Arizona stood third in the copper-producing districts of the United States. Since that time, with the development of porphyry mines, the output has gone up with great rapidity until it not only is the leading district, but its output at the present tune is at the rate of nearly double the Montana output; which now stands second in the list. In connection with this development, most interesting departures have been made in methods of mining, concentration and smelting. Principles of mining and metallurgy of the greatest interest will be covered by papers which will appear in the Bulletin and be presented at Technical Sessions, while ample opportunity 'will ,be- afforded for those who go to the meeting to see all the points of interest to them. In addition, members will be well rewarded by the marvelous natural features to be seen on the trip, including the petrified forests, the cliff dwellings on the Apache Trail and the Grand Canyon of Arizona. It is planned to start the special train from New York, but members and guests may join the special at other points en route as indicated by the following schedule: ITINERARY Thursday; September 14th, Lv New York Grand Central Terminal 5.30 p.m. Dinner in dining car, a la carte

Jan 9, 1916