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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

In July 1946 President Truman approved the stock- piling act providing for the accumulation of stocks of strategic minerals in which this country is deficient. Congress also provided huge sums for the purchase of these materials to initiate the program. In order to meet anticipated stock pile goals it will be necessary for the United States to import very large quantities of 70 strategic materials, by far the largest items being minerals and metals. There are no priorities of relative importance in the list, as the lack of any single item may cause industry to fail in its part in national defense. Stock piles of material in a form as close as possible to the ultimate fabricated state represent not only the actual material physically on hand but also "canned" labor, transportation, smelting, refining, and all other steps. Central and South America, together with Canada and Newfoundland, in their normal capacity as sources of supply will be called upon to furnish a sizable pro- portion of the total requirements. No special measures should be arranged for this purpose; it will be more practical to make purchases in accordance with the availability of materials of desired quality, not by reference to geographic area. Much has been said in the past, and may be repeated in the future, concerning the desirability of hemispheric self-sufficiency-both from a resources and from a military security viewpoint. The mineral industries cannot favor the principle of eco-

Jan 1, 1950

In cooperation with the United States Bureau of Mines and the Idaho Bureau of Mines and Geology, the University of Idaho offers in the School of Mines a number of fellowships. These fellowships are open to college graduates who have had good training in mining, metallurgy, or chemistry, and who are qualified to undertake research work. The income of each fellowship is $720 a year for the 12 mo. beginning July 1, 1919. Fellows will register as students in the University of Idaho and become candidates for the degree of Master of Science in Mining or Metallurgy (unless this or an equivalent degree has been earned). Their class work-will he directed by the heads of the departments of instruction, but the greater portion of their time will be spent in research work under the direction of the Bureau of Mines staff resident at the University. The purpose f this work is to undertake the solution of definite problems confronting the mining and metallurgical industries of the State of Idaho. For 1919-20 the following subjects are being considered: 1. Flotation-with especial reference to differential separation of various minerals. 2. Availability of western wood oils for flotation purposes. 3. Treatment of the complex gold-silver ores of southern Idaho. 4. Ore-dressing problems. 5. Mining problems. Applications, with certified copy of collegiate record, statement of professional experience, and names and address of three references, should be addressed to The Dean. School of Mines. Moscow Idaho_

Jan 6, 1919

By Rossiter W. Raymond

The substance known as carbonite, or natural coke, has been several times the subject of comment before the Institute. The most important contribution hitherto made to the discussion is that of Dr. Henry Wurtz, of Hoboken,* who states, upon the strength of a chemical analysis, that carbonite is not a coke, but contains 14.08 per cent. of volatile combustible matter. In 1882 a mine was opened upon a carbonite seam, near Midlothian, Chesterfield County, Va., by Messrs. Jewett & Brother, of that place. The seam, which dips westerly at an angle of about 30 degrees, was struck at the depth of 137 feet with a vertical shaft, and followed on the dip 325 feet, at which depth gangways were opened north and sooth. For these statements (having made no personal examination of the locality), I am indebted to Mr. Albert Blair, of Richmond, and for the following section, to Mr. John Bladon, engineer at the mine. The section was taken in the face of the gangway, February 17th, 1883. It shows an aggregate thickness of 15 feet of "coke," of which about 5 feet were extracted by the system employed last winter. It is reported that under the "coke" seam there is a thick seam of highly bituminous coal, which has been extensively worked on a neighboring property, a little south of the Jewett colliery, the coal being sold for gas-waking. The carbonite is used for domestic purposes, and is said to burn

Jan 1, 1883

ENGINEERS AVAILABLE. (Under this heading will be published notes sent to the Secretary of the Institute by members or other persons.) Member, graduate of College of Mines of University of California, with 12 years' operating experience in mining and milling in California, Canada, and Mexico, is open for engagement. Speaks Spanish fluently. No. 17. Mining engineer and metallurgist open for engagement Jan. 1 as superintendent of mines or constructing engineer. Technically educated, with 14 years' experience in United States and Latin America in concentration, amalgamation, cyaniding, constructing. At present building large modern .all-sliming cyanide mill in Central America. No. 18. Member, mining and metallurgical engineer, is open to engagement. Specialty, the treatment of copper ores. Nine years' experience in the operation and also in the design and erection of copper smelteries. Four years true pyrite smelting. Able to organize the administration, accounting, etc., of a large plant. Speaks a fair amount of Spanish, Russian, German, and French. Qualified to take charge of a large smeltery, or to act as assistant to manager of a combined mining and smelting concern. No. 19. Member, technical graduate, 33 years old, 11 years' experience as chemist, metallurgist, and superintendent of lixiviation plant and in charge of construction of cyanide mill, is open for engagement. Speaks Spanish. No. 21. Member, lately with the Bishop Creek Milling Co., California, is now open for engagement as mine superintendent or superintendent of construction of mine and mill structures. No. 25.

Jan 12, 1913

By M. L. Brashears, R. G. Slayback

The host dolomite of the Pine Point lead-zinc ore is a prolific ground-water aquifer that occurs locally under watertable and artesian conditions. Mining schedules and severe climate require rapid and thorough dewatering of open pits. Pumping-test methods, common to ground-water supply studies, were applied to dewatering design for a model ore pit in 1968. Procedures for testing and design at other ore bodies were established and have been carried out successfully by mine personnel. At the inception of ground-water studies, parts of ore bodies were below prevailing ground-water levels by 35 to more than 150 ft. Movement of ground water through the coarsely recrystallized dolomite occurs largely through fractures and solution openings. Because the overburden deposits consist mainly of glacial till, it is estimated that the recharge to the aquifer is about 25% of the 13-in. annual precipitation. Natural groundwater flow is northeastward toward Great Slave Lake. Background data included extensive diamond drill hole logs and cores and static level data for a number of ore pits. An ore pit, known as N-42, that required 40 ft of dewatering was selected for the initial application of the pumping-test method. Production wells, cased with 14in. pipe, were drilled to a depth of 300 ft on the rim of the ore pit. A suitable pattern of observation wells was obtained by lining 21/8-in. diamond drill holes with perforated electrical conduit. A two-stage pumping test

Jan 1, 1973

By William Garrett

I have heard it said that the late Mr. Holley made use of this remark: " There is an inherent, cussedness about rolls which, so far, no man has been able to find out." I think this can be safely claimed in reference to steel, as there are certain peculiarities about it that are pretty hard to account for. Previous to the introduction of the Bessemer process there was, as it were, a great chasm between iron and crucible steel; and, outside of what futile attempts had been made in puddling steel, nothing had been done to fill this gap. The Bessemer steel struck a medium between the two, the softest of it not being able to take the place of good iron, while the hardest was not suitable to encroach very far upon the crucible-steel trade. The open-hearth process made quite an inroad into the latter, but only for the lower and cheaper grades; and, beyond a doubt, for the finest grades of tool-steel, the cruciblesteel business has a long life before it. On the other side of the line comes the " basic " process, which brings us a step nearer iron ; but to fill up the gap completely, comes the Clapp-Griffiths process, which makes a grade of material—call it what you will—that is as soft as iron, welds as readily, and is in a fair way to supersede iron altogether. For fifteen years, I was in the employment of the Cleveland

Jan 1, 1886

By J. J. Donos

IN the operation of a smelter, continuous and accurate determination of smoke losses is essential for purposes of metals inventories and as a check on the efficiency of smoke recovery apparatus. Previous to the development of a continuous and automatic smoke sampler by R. MacMichael, in 1924, two methods were in vogue, and still are in some smelters, for measuring solids passing out of a flue or stack. These are: (1) the so-called dust concentration method whereby the gas volume passing through the flue is first measured and then the total amount of solids carried in the smoke stream calculated from the weight of suspended matter filtered out of a measured volume of gas; (2) the balanced tube method is independent of gas volume flowing through the flue, and relies for its accuracy on the fact that a true smoke sample may be taken if the velocity of the gas in the sampling tube is constantly maintained at a known ratio of the average flue gas velocity. The total amount of solids passing through the flue is then proportional to the weight of filtered solids and to the ratio of the area of the flue to the area of the sampling tube, corrected for the velocity ratio. The limitations of the first method lie in the uncertainty of the varying volume of gas arising from metallurgical operations and the unreliability of ordinary gas meters to hold their accuracy under

Jan 1, 1951

ARTICLE I: NAME AND OBJECTS Section 1: This Division shall be known as the Iron and Steel Division of the American Institute of Mining and Metallurgical Engineers. Section 2: The objects shall be to furnish a medium of cooperation between those interested in the metal-lurgy and industry of iron and steel manufacture and use; to represent the A. I. M. E. in so far as ferrous metallurgy is concerned, within the rights given by A. I. M. E. By-law XVII, Section 3, and not incon-sistent with the Constitution and By-Laws of the A. I. M. E.; to hold meetings for social intercourse and the discussion of ferrous metallurgy; to stimulate the writing, presentation and discussion of papers of high quality on ferrous metallurgy; to reject or accept such apers for publication and distribution by-the A. I. M. E. within the limits of the funds available for such purpose. ARTICLE II: MEMBERS Section 1: Any Member, Associate, or Junior Asso-ciate of the A. I. M. E. in good standing may become a Member, Associate or Junior Associate of this Divi-sion upon registering in writing a desire so to do. Section 2: But no one who has been continuously indebted to the. A. I. M. E. or to this Division for more than three months shall be entitled to vote or to receive publications to which, as a member of the Division, he would be entitled.

Jan 7, 1928

By F.L. Preshidge

R. B. RATHBUN,* Salt Lake City, Utah (written discussion?).¬While the engineer should carefully weigh the merits of the various types of equipment, he must bear in mind that the object of his plant is the recovery of suspended solids, and a thing is unimportant except as it contributes to this end, other engineering principles being duly considered. The controversy regarding the use of synchronous motor-driven rectifiers by which the power for the treater is taken directly from the mains of the local power system, rather than the motor-generator rectifier giving each treater unit its own isolated electrical system, has led many to think that on the type of rectifier depends the success of .the plant. It is in fact a relatively unimportant part of the plant and represents a very small fraction of the investment; the recoveries in dust and fume are practically the same in each case. One large smelting concern has adopted the motor-generator type for all of its plants after years of experience with the synchronous-motor type. Its reasons are practically the same as those set down by Mr. Eschholz for his preference. Given more in detail they are: 1. An independent electric system prevents outside power-line conditions, like voltage fluctuations, from interfering with the operation of the Cottrell plant and eliminates the possibility of the Cottrell plant causing trouble for the power company. The latter, while not very

Jan 12, 1918

C. Le Neve FosteR, Llandudno, Wales: I regret that Prof. Clowes is not here, and also that I cannot produce one of his lamps for inspection. The lamp has but just passed the experimental stage, and is now on sale in England for the purpose of testing it in practice. The only complaint I have heard made against it is the high price. It costs six or seven guineas. Possibly that would not frighten you on this side of the water as much as it does us. R. W. RaymonD, Brooklyn, N. Y.: So far as my obsrvations and experience go, we have not yet reached a state of affairs in the coal-mines of this country which calls for the general use of safetylamps by common miners. Certainly such a practice is to be avoided if possible, on account of the recklessness of miners, which it seems almost impossible to control by warning or discipliue. It is much better, if practicable, to confine the use of safety-lamps to inspectors or " fire-bosses," and not to permit the miners to work or to go where naked lights cannot be carried. In a colliery near Pottsville, Pa., with which I was connected for five years, and which had the reputation of being highly "fiery " (jets of fire-damp bubbled continually through the puddles in the gangways, and a thin sheet of it lay along the roof), we managed to avoid all serious

Jan 1, 1894

By D. L. Harris, A. M. Gaudin

THE following results, presented here in condensed form,1 were obtained in a preliminary study of the adsorption of n-hexane thiol, hexyl mercaptan, on sphalerite, zincite, willemite, and quartz, from aqueous solution and from a gas. Interest in this subject was aroused by a Belgian report2 of effective use of hexyl mercaptan for flotation collection of oxidized zinc minerals. The relatively low boiling point, 149°C, of the mercaptan3 suggested the desirability of extending the usual measurements of partition of collector between aqueous solution and gas and between gas and mineral. It is believed that this paper presents the first measurements of this type on a flotation system. Attempts were made to carry out the measurements at equilibrium, but as the work progressed it became increasingly doubtful that this desirable condition had been achieved. To control composition and extent of the gas phase, the apparatus was a wholly-enclosed thermally-controlled glass system. Because of these constraints and the desirability of dealing with pure minerals, a scale of operations was chosen in which a few grams of deslimed mineral were used in each test. It was also necessary to choose a particularly sensitive method for mercaptan analysis, and in fact a method that would permit the experimenters to follow the approach to equilibrium. For these reasons mercaptan marked by radiosulphur 35 was used. An analysis was made for the radiosulphur by a modification of the method of Gaudin and Carr.4

Jan 9, 1954

By P. H. Royster

IN a study of the blast-furnace process, the Bureau of Mines has made many experiments for the purpose of determining the exact nature of the combustion of coke in the neighborhood of the tuyeres. Two papers1 presented at a meeting of this Institute discussed somewhat the practical aspects of coke combustibility in its relation to the operation of the blast furnace. In a later paper,2 Sherman and Kinney discussed the possible effect of variations in the combustibility of cokes on the furnace operation, and find that the "reoxidation theory" of Koppers and the "heat concentration theory" of Brassert3 are insufficient to explain the variation in the conduct of different cokes that has been observed by furnace operators. In their report to the D-5 Committee of the American Society for Testing Materials, with which the Bureau of Mines has been cooperating, Perrott and Fieldner4 seem to agree with Sherman and Kinney that, for practical purposes, the nature of the combustion of coke at the tuyeres of any furnace is constant and is affected neither by the physical properties of the coke nor by the nature of the furnace operation. They omit as unimportant any tests on the combustibility of coke from their proposed methods for standard tests on coke. In the last two papers, it is pointed out that performance tests, in which all other factors except coke quality are kept constant, are to be desired and

Jan 3, 1924

By Reamy Joyce

CONDITIONS in underground mining are so variable that in approach-ing the problem of the economies effected by the use of pressure-treated mine ties and mine timbers, it is necessary to secure specific data for each mine. Facts must first be dug out to show the service life of untreated timber and the reason for its failure. Generally speaking, decay is the usual cause of failure, but in some mines mechanical destruction is an important factor. Occasionally the two causes combine to produce fail-ures, and it is difficult to determine positively which factor is responsible. In making comparisons, it is always necessary to start with the cost in place and for this reason there must be accurate information covering the labor cost of installation and the labor cost of renewals. When treated timber is used, it is necessary to know the specifications for the treating process, whether the timber was painted, dipped, treated open tank, or impregnated under pressure according to standard specifica-tions. It is also necessary to know the preservative used and the amount of the preservative that was retained by the timber after treatment. It is also well to know whether the timber was thoroughly air-seasoned before treatment or was green at the time it was treated. The kind of timber available, both untreated and treated, must be known and all of the factors listed above must be taken into consideration in the study of any problem.

Jan 1, 1939

The income of the Institute is derived mainly from dues, advertising in MINING AND METALLURGY and sale of publications. These sources fortunately are supplemented by the interest from invested funds now amounting to over $500,000, a considerable portion constituting endowments for special purposes. Aside from the medal funds the principal endowments are the James Douglas Fund for support of the Library, the Charles Hayden Memorial Fund, designated to further the education of Student Associates, the Rocky Mountain Fund, and the Seeley W. Mudd Memorial Fund. The income from the two last named is available for the support of research and a variety of other purposes. It is allocated by the Board of Directors upon recommendation of standing committees in each case. An active effort is being made to increase the endowment funds of the Institute through a standing, committee, of which H. T. Hamilton is chairman, and of which the other members are: W. H. Aldridge, George D. Barron, Cleveland E. Dodge, Henry Krumb and J. V. W. Reynders. This committee feels that there exists a tremendous opportunity for the Institute to be of ever-growing service to the public, to the mineral industries, and to the profession. It welcomes suggestions as to names of men of means who are vitally interested in the mineral industries, and to whom the opportunity to make a contribution or bequest might appeal favorably if presented in the proper light by the committee.

Jan 1, 1940

By J. E. Flinn, E. R. Gilbert

Recently, Green reported some high-temperature, 0.60 to 0.89 T3, creep results on unalloyed tantalum. From his study he determined an activation energy of 114 kcal per mole for steady-state creep using the T, differential-temperature method25 for testing. He accounted for the difference between this value and 110 kcal per mole for self-diffusion by the temperature dependence of the elastic modulus, 4 kcal per mole. This reported activation energy is in apparent disagreement with that which can be determined from Green's isothermal data, which we have plotted as log creep rate vs 1/T in Fig. 15. From this figure, it appears that there are two activation energies of -185 kcal per mole at the higher temperatures and -75 kcal per mole at the lower temperatures. It is not obvious that the data can be fitted to a straight line corresponding to an activation energy of 114 kcal per mole. One is led to two possible conclusions regarding Green's study: there are two discrete processes controlling the creep rate from 0.60 to 0.89 Tm or the apparent activation energy is not discrete but continuously increases with increasing temperature. The former speculation would be in closer agreement with the high-temperature creep behavior of tungsten.28 The apparent disagreement between the activation energies determined by the AT and isothermal methods certainly suggests that further study on the high-temperature creep of tantalum is needed.

Jan 1, 1967

By G. St. J. Perrott

AN explosive of, balanced composition might be expected, on first consideration, to develop maximum propulsive strength.1 This hypothesis is based on the assumption that an excess of oxygen would act simply as an inert material with a consequent lowering of flame temperature, also that a deficiency of oxygen would tend toward incomplete reaction of the combustible materials, thereby preventing development of the full strength of the explosion. Actually, however, it can be shown both theoretically and experimentally that an explosive having a certain oxygen deficiency will develop the greatest propulsive strength. This fact has been known to the technical staffs of explosives manufacturers for many years, but it has not always been recognized by explosives engineers in the field. For example: There: is a fairly widespread opinion that the wrapper of a stick of dynamite is merely a container for the explosive and that it plays little if any part in the development of propulsive strength. Actually, it can be shown that the wrapper enters fairly completely into, the explosive reaction. In the case of most gelatin dynamites, a given weight of explosive from which the wrappers have been removed will develop considerably less strength than the same weight of explosive plus wrapper, in spite of the fact that the latter combination contains less weight of the actual explosive ingredient. It can also be shown that a cartridge 7/8 in. in diameter may be stronger, weight for

Jan 1, 1928

By J. H. Keeler

QUESTIONS raised during earlier investigations of the preferred orientation in titanium1 and zirco-nium sheet led to the examination of the rolling and annealing textures of beryllium and hafnium sheet. Since the c/a ratios are 1.568 and 1.584, less than that of ideal close packing, 1.633, it would be expected that the preferred orientations would be similar to those exhibited by zirconium and titanium. This was found to be true. However, in several regards the orientations observed for beryllium differed from those reported by Smigels-kas and Barrett4 and so are given here. The okientations for hafnium are presented since only the cold-rolling texture has been reported in the unclassified literature. The pole figures were determined by transmission using an X-ray spectrogoniometer with copper Ka radiation and the automatic pole-figure recorder designed by Geisler described previously.6 The intensity units in the pole figures in this case are only arbitrary since calibration against a random sample of the same material was not considered necessary for the original purpose of the examination. The beryllium sheet, cold-rolled from 0.036 in. to 0.006 in., a reduction of about 84 pct, exhibited a split texture with the [1010] direction in the rolling direction as shown in Fig. 1. The same specimen annealed in vacuo for 1 hr at 1000°C showed no change in orientation. These textures

Jan 1, 1959

By E. A. Wieselmann

This chapter presents a successful approach for achieving mine entry stability at the Cane Creek potash mine by the utilization of closure measurements. The mine is located in southeastern Utah (Fig. l). Mining is being conducted at depths in excess of 3000 ft under structurally complex geologic conditions typical of the Paradox salt basin. The closure measurement systems described have definite application for determining relative entry stability in other nonelastic rocks which are similar in behavior to potash. Similar types of closure measurements have been taken in various underground openings throughout the United States, Canada, arid Europe. Application of this closure data has previously met with varying degrees of success as a tool for design of under- ground openings in both elastic and nonelastic media.1-32 Closure measurements can be made easily and economically and they provide a practical solutiori to a practical problem. They are in-situ measurements which do not necessarily require laboratory correlation. Simple closure measurements have special significance in potash because "steady-state" ' closure rate, or creep, of the entries is measured. These closure rates can be utilized because nonelastic media such as potash will never achieve absolute stability around a mine entry. The potash will tend to creep or deform until all entries are closed and the overburden stress is redistributed over what was previously the mine area. The time for this ultimate effect to occur is dependent on a number of mining and geologic variables. Percentage of mine extraction, mining

Jan 1, 1972

By J. M. Gaines

THE use of oxygen in electric furnaces is relatively old, and the practice has been employed by several steelmakers prior to the recent impetus given generally to the use of oxygen in steelmaking. This application has been described recently in several publications,1 and a number of patents relating to the application of oxygen in electric furnaces have been issued.2 An effort is made in this paper to assemble recent information relating to the use of oxygen in electric furnaces and to present this material from a practical viewpoint, to an extent consistent with the withholding of certain operating data which manufacturers consider to be confidential. The use of oxygen has been extended during the past months in a number of additional steel companies by incorporating oxygen practice into regular production and by much increased experimentation. Available records show that oxygen is used more or less regularly at present in 18 shops, of which six utilize the oxygen for production and the others for experimen¬tation. The number of furnaces per shop using oxygen varies from one to six. Many types of electric-furnace steel have been prepared with the assistance of pure oxygen, including low-carbon and medium-carbon killed steels, low-carbon rimming steel and low-carbon and medium-carbon stainless and alloy steels. Oxygen has been used in furnaces of all sizes up to 90 tons capacity for accelerating charge meltdown and for reduction of carbon.

Jan 1, 1947