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By Alvin Kaufrnan

This chapter will deal with the policy issues relating to mineral land disposal. The first portion of the chapter will discuss in general terms the legal systems utilized in disposing of mineral rights and the major problems encountered; the second section will comprise an analysis of the policy alternatives with emphasis on the pricing aspects. In this section, we are not attempting to provide a legal text, but simply to outline very briefly and sketchily the details of the systems. More detailed information can be obtained by contacting the appropriate governmental agency for specific information. Mining laws throughout the world are based on two major legal groupings: English Common Law and the Civil Law. These basic systems are often modified by Islamic Law and by negotiated -mixtures of these. Under English Common Law, which is embraced by the United States, Canada, and many of the members of the British Commonwealth of Nations, individuals can hold property and can extract minerals from it. The owner can dispose of minerals as he sees fit, either through contract, deed, or whatever other system is appropriate. CIVIL LAW Under Civil Law (also known as Regalian Law), mineral ownership is normally placed in the state, regardless of who owns the surface. This legal system applies in most European countries and their former colonies. It is derived from Roman law. The mineral deposits, thus, are worked under concessions. Most countries use a negotiated concession system and sometimes a combination of negotiation and competitive leasing. The negotiated system has advantages as well as disadvantages for both government and industry. In a system where the government administratively determines who is to get what, the concessions are normally large. Frequently they range up to several millions of acres and involve a considerable investment on the part of the concessionaire. There is no duplication of effort on the part of producers to obtain information, since a single concessionaire controls a given area. Consequently, less money is spent in toto because several prospective operators are not required to seek the same information. The system also has the advantage to the industry of permitting the concessionaire to select and retain the best producting area. Thus, major developmental expenditures are made on the production unit only, with a resulting reduction in the risk factor. The large initial size of the concession also minimizes the possibility of expending a large bonus payment for a barren property. The major governmental advantage of a concession is its flexibility in accomplishing other national objectives. For example, a lease could be negotiated at less than fair market value, but requiring substantial de-

Jan 1, 1976

AS If see it, then, the engineering advances of which yob have studied here at Golden, the continued growth of. industry that you see about you here in Colorado, and the country-wide progress that I have not time to discuss-these illuminating facts should clear away any doubts as to your future. You have little license to ask, "Where is the call for engineering or what the need? Yankee fashion I might ask you by way of reply, "Have all the mines been opened? Have all the power-houses and transmission lines been built? Have the last improvements in. mill and smelter been in-stalled?" We know that the general answer is No, and the rest of the answer, which tells where are those mines and power plants and what are the new methods and processes in mining and metallurgy, must be sup-plied by you engineers of the future. And anyone who has even casually observed what recent years have brought forth in our profes- sion cannot but envy you your job. Our reconnaissance excur-sion into your future should not be much longer extended, but before turning back there are four landmarks that I would like to point out-not lofty peaks but useful tie points that are worthy of your attention as you traverse the territory of your future work. Two of these are in fact low spots or depressed areas which call for engineering activity; these are commonly called "waste" and "average." The other two are of larger significance and are rather extensive regions in the domain you are to enter and occupy. These larger tracts bear the suggestive place names "fact-finding" and "human engineering" and perhaps will prove to be the heights from which the broadest outlook is to be had in this "pilgrim's progress:" In the first place, waste deserves your attention, al-though I realize that it is possibly the most unpopular word anyone hailing from Washington can publicly utter. Its unpopularity naturally follows from its overuse in the somewhat strong charges made against the industrial and business world some years ago, when the doctrine of conservation was first preached in the land. But waste is a word to be used in an engineering sense as well as for political effect. Properly used, waste is not a word to shy at-rather it is a challenge to the engineer. For example, at present, the loss of 1 kilowatt-hour to every 5 sold is a clarion call to the electrical engineer. Waste is your target to shoot at, the obstacle for you to surmount, the giant for you to slay.

Jan 7, 1928

By Park Wright

The fact that granite has been encountered by the drill by those in search of oil and gas in Kansas is becoming more and more a matter of interest, not only to the oil producer but to everyone directly and indirectly connected with the oil business. It is, therefore, time that someone should offer an explanation for its presence and form a definite opinion, based on all the data available, in regard to the effect it will have on the future prospects of the area affected as probable oil-and gas-producing territory. At present there seems to be no consensus of opinion. To the writer's knowledge, only one attempt has been made to explain ; by Erasmus Haworth, State Geologist of Kansas, in a paper entitled Bulletin Number Two on Crystalline Rocks in Kansas. The purpose of the present paper is to offer a theory for the presence of the granite, and to draw conclusions which will aid in determining the prospective oil and gas value of the area in question. In taking up this question it will be well to consider first the tests in which granite has been reported, with a general history of each. The accompanying map (Fig. 1) shows the location of all wells described. The first well in which granite was reported was that drilled just south of Zeandale in section 27, township 10 south, range 9 east, by a local company which had taken up a block of leases in that vicinity. At a depth of 958 ft. (291.99 m.) granite was encountered. Drilling was continued to a depth of 1093 ft. (333 m.) in the same formation, at which depth the hole was abandoned. Another well was started 1 mile east of the first well and the same rock was found at a depth of 945 ft. (288 m.). Drilling was continued to a depth of 1200 ft. (365.76 m.) with the bit in the same formation. Samples of the drill cuttings have been examined and they are undoubtedly crushed granite. The next well in which granite was found was that drilled by DeLaat and Shepard, independent wildcat operators, in section 34, township 19 south, range 7 east, near the town of Elmdale. Granite was struck at 1707 ft. (520 m.) and the hole was abandoned in the same formation at 2525 ft. (769 m.). Mr. DeLaat watched the drilling of this well very closely and he has described to me in some detail the formation immedi-

Jan 1, 1918

JAMES E. HOWARD,* Washington, D. C. (written discussion?). -Mr. Comstock, in his classification of the possible causes of transverse fissures, has not quite caught the point of view of the writer. It appears, following the trend of thought in Mr. Comstock's paper, that three groups instead of two might bee enumerated, namely: Fatigue of the steel, quality or, preferably, grade of steel, and mill practice. All steels are liable to failure by fatigue. Stresses that are capable of causing fatigue fractures are modified in their magnitude by the grade of steel acted upon. Mill practice is a term having a very wide meaning and in its relations to the development of transverse fissures has been used with such vagueness as to include many known factors and some that are unknown in the arts. According to the grade of steel employed, fatigue fractures may be accomplished by loads of greater or less magnitude, hence there is a relation between quality, or grade, of steel and the display of fatigue fractures. Mill practice of such an order as to affect the formation of transverse fissures must be shown to exert an influence on the ability of the steel to endure repeated stresses. Different grades of steel are selected for different purposes. Steel employed for fire-box purposes is of different grade from that used for cutting tools; although each grade is suitable for its purpose, and therefore of good quality. It is conceivable that a demand might be made for steel of physical properties in excess of those of any known grade. Under such a demand, impossible of' fulfillment, it would not be proper to refer to the steels as being deficient in quality; to do so would be a failure to recognize that all steels have their limitations in strength. Service conditions peculiar to rails admit of successive advance until the conditions can no longer-be met. The failure of a large number of rails from one type of failure, when all known means of averting the failure have been employed without success, is sufficient evidence that the end is close at hand. Iron rails, for a time, successfully met the requirements of railway service but weight of equipment, motive power, and rolling stock were increased, necessitating the use of steel. The early steel rails enjoyed the reputation of being of excellent quality, although: neither chemically nor structurally would they be so regarded ,lit the present time. They did good service in their day and under the conditions then prevailing were good rails. To meet the increased weight of rolling stock there has been

Jan 3, 1919

By W. N. Carr, J. R. Biard, B. S. Reed

An analysis of the semiconductor injection laser is presented which is based on a phenomenological model using device and material parameters. The intent of the laser threshold analysis is not to predict from theory the actual threshold current density but rather to provide a logical means of interpreting experimental results. The device and material parameters have been selected such that they describe both the threshold conditions and quantum efficiency of the lasev. A technique is proposed whereby the current required to obtain a population inversion is predicted from device 1-V characteristics. Experimental data are presented which support the analysis. THIS investigation is concerned with the characteristics of GaAs lasers fabricated in this laboratory. However, the assumptions used in these calculations should not limit their application to GaAs alone. It is felt that the analysis is sufficiently general to be useful in describing the operation of other semiconductor-laser materials. ANALYSIS heavily doped semiconductors to be considered. The absorption and/or generation of optical radiation may be completely specified in terms of q(E) and the probability functions f,,(E) and f,(E) which define the occupancy of the valence-band and conduction-band levels, respectively. The symbols used in this analysis are listed at the end. Following the approach of all' it can be shown that the effective gain coefficient, g, in the plane of a forward-biased P -N junction is g(E)=-ai@)[1-fv(E)-fc(E)] [1I In particular Eq. [I] holds for the photon energy at which lasing occurs, Ep. Throughout the following discussion Eq. [I] is considered only for the lasing transition E = Ep. For simplicity the functional energy dependence of the various factors is omitted in subsequent equations. Unless otherwise stated the symbols used represent the values at Ep. If the analysis is limited to the P-type side of the laser junction, the function q(l -f,,) is recognized as the band-to-band absorption in the P-type material at thermal equilibrium. Under forward-bias conditions the function f, is determined by the electron quasi Fermi level in P-type material. For sufficiently large forward bias the second term in Eq. [3] will become dominant and net gain will result; i.e., g will become positive. In order to simplify the subsequent analysis several assumptions are in order at this point. a) No conductivity modulation occurs. /„ is independent of f, and therefore go is a constant. b) The P-type material is heavily doped such that the degeneracy of the valence band permits popu-

Jan 1, 1964

By A. A. Smith

The application of indium to bearings was first advocated by C. F. Smsrtl in 1938, for the purpose of inhibiting corrosion of certain bearing alloys. He found that a thin layer of indium plated on the bearing surface and subsequently diffused at elevated temperatures markedly decreased the rate of corrosion in lubricating oils containing organic? acids. Most of his work was done on cadmium-base alloys, although he showed that the treatment was also effective for copper-lead and other; alloys. Since their introduction, indium-treated bearings have found considerable use, particularly in connection with airplane motors.2 Undoubtedly the effectiveness of the indium plate in resisting corrosion depends upon its relative concentration on the bearing surface after the diffusion treatment and after prolonged use at operating temperatures. Some diffusion experiments were made on a number of base metals that had been indium plated, to determine the depth of penetration after heating for reasonably long periods of time. As only the practical aspects were desired, no attempt was made to determine actual diffusion constants. Method Two different series of experiments were carried out to study the diffusion of indium into several base metals. Cast cylinders about one-inch diameter were machined to 0.750-in. diameter, so as to remove all surface imperfections, and final finishing was done with oo sandpaper. The original diameters were very carefully measured with micrometers and then a layer of indium was electrolytically deposited on the cylinders from a sulphate bath.3 In the first series of experiments, about 0.002 in. of indium' was deposited and diffusion, was carried out at 150°C. for a period of 500 hr. in a thermostatically controlled electric oven. After the diffusion period, successive layers were machined from the specimens and analyzed spectro-graphically and chemically—the spectro-graphic examination serving as a guide to determine which layers should be chemically analyzed. Apparently there was some surface oxidation of the indium plate due to the long heat-treatment, which may have had some effect on the diffusion. A1so, the cadmium alloy showed some incipient melting, which probably was caused by the formation of a low-melting eutectic. To eliminate these factors, another series of experiments was carried out by heating in an electrically heated, automatically controlled, oil bath at lower temperature. The preparation of the specimens was the same as before except that a layer of indium 0.0001 in. thick, an amount commonly used commercially on bearings, was deposited on each of the cylinders. Diffusion was carried out at 120°C. for a period of 200

Jan 1, 1944

By E. C. Harder

J. T. SINGEWALD, JR., Baltimore, Md.-I might say a word further in regard to the Miguel-Burnier district. I am sorry Mr. Harder is not here. I had hoped to be able to ask him a few questions in regard to some of the features of those deposits. This Miguel-Burnier district is the other district that I referred to that lies in the State of Minas Geraes. The interpretation that Mr. Harder gives to, these deposits is the same as that given by Harder' and Chamberlin in a previous paper, and that is that they consist of lenticular deposits of sedimentary origin in a series of rocks that also include lenses of limestone, but they seem to think that the manganese ores occur at a definite horizon and at a horizon different from the limestone. We found that the manganese ores occur at several horizons, as also do the limestone lenses, and the limestone masses are of the same shape as the manganese orebodies, so that our own feeling was that these manganese ores simply represent concentrations within the zone of oxidation formed as. a result of decomposition and replacement of this limestone. To the east of Miguel-Burnier there is a big bend in the railroad which cuts through, at right angles to the strike, this series of rocks. Here is shown very well both the local character of the limestone lenses and the local character of the manganese lenses in that, though the distance across the bend is only a couple of hundred yards, the limestone and. ,manganese lenses do not match up at all, and it also shows plainly that both occur at more than one horizon.. Consequently there is no reason why the manganese ore could not represent alterations of this limestone. The mine workings do not as yet give very definite information on this point in that they are all comparatively shallow and within what would be the zone of oxidation so that what they will grade into below that depth, we do not know. On the other hand, the character of the ore suggests that it may, represent such -a product in the zone of oxidation in that it tends to be quite earthy; whereas, if the manganese had been there originally as such it would have undergone the same metamorphism that the other rocks have undergone and one would have expected that it would have been converted into a hard manganese ore that would today stand out pretty much as do the iron ores of that same region and not have the soft, earthy texture which is a prevailing characteristic.

Jan 4, 1917

By Edward S. Cook

For several years past, dating particularly from the days of serious "ore-dirt" complications at the Warwick furnace, I have been desirous of providing some safe, quick and easy method of relieving the tuyeres of slag, when the cinder- and iron-notches are chilled through loss of heat in the clucible or when, from dropping or jumping of stock, the molten slag is forcibly driven into the bellyand leg-pipes. Various methods were proposed, but objections of one kind or another always presented themselves, and the subject was postponed to a more convenient season. In the summer of 1887, while running on anthracite alone, 1 found the various expedients in use to be so utterly valueless, that the importance of a practicable tuyere slagging-valve impressed me more forcibly than ever. The holes left in the cast-iron jacket at one side of the bottom of the water-blocks were found to be of no value whatever. The swinging or hinged cap on the elbow of the belly-pipe, while convenient to permit the removal of lag after the belly-pipe was partially or wholly filled, could not be adapted to discharge the slag before solidifying, except at great risk to the men and loss of time just when the constant running of the engine and the keeping of blast on the furnace was of the utmost importance. By removing keys from the caps and holding them in place with props, the slag could be discharged through the tuyeres and belly-pipes, with the engine running, by knocking the props away at a given signal. This method is extremely hazardous to life and limb, and I have always hesitated to make use of it. When the furnace is in such condition as to require the adoption of some method of the kind, the stoppage of the engine, cooling the blast and the contents of the crucible, always aggravates the trouble. When the caps are blown open and the slag is discharged by removal of the props, it is necessary to stop the engine to replace them. An hour or more will elapse before this can be done, as the slag must be partly removed before the tuyeres can be approached by ordinary mortals, and the caps handled and fastened in place again. Any movement of the stock is liable to burn the workman, as he stands, securing the cap in front or at one side of the open belly-pipe.

Jan 1, 1889

By Frank H. Macpherson

When it became apparent early in 1941 that the United States might be drawn into the war, studies were made of the bauxite situation in Arkansas, principally because 9.5 pct of the known bauxite reserves of the country were located in that State. Bauxite mining was then geared for maximum production to supply ore to meet this country's war requirements and, if necessary, to supply the needs of Canada as well. In view of the comparatively small bauxite reserves, Congress appropriated funds for an extensive exploratory drilling program to be carried out by the Bureau of Mines in cooperation with the Geological Survey. An alumina plant was erected near Bauxite and an aluminum plant near Hot Springs, Ark., by the Defence Plant Corp. The Metals Reserve Co. established a schedule of prices, arranged for stockpile sites and a buying agency. Operators cooperated to step up production and new ones came into the field. Production Record Prior to 1941, the greatest annual production in Arkansas was 562,892 long tons, dry basis in 1918. During the single month of August 1943, 693,596 long tons were mined—130,704 tons more than for the entire year of 1918. In general the Arkansas bauxite deposits are relatively small, irregular in thickness, somewhat scattered and, compared to coal, iron or open-pit copper deposits, are ill-adapted to an expansion in output. Commercial deposits range in horizontal extent from less than an acre to about 40 acres and are usually very irregular in outline. The average thickness of all known workable deposits is between 12 and 15 ft. with a maximum of about 60 ft. The ore bodies are usually somewhat undulating and nearly horizontal although locally some deposits dip as much as IS°. Types of Bauxite Three physical types of bauxite may be recognized: pisolitic, granitic and amorphous. Pisolitic ore is the most common type. It consists of small pebble-like nodules, ranging from the size of a pin head up to several inches in diameter, all set in a fine grained matrix. Transported bauxite is usually- pisolitic. Most residual bauxite is granitic. It is believed not to have moved appreciably from the location where it originally was formed. This is indicated by the fact that it appears to grade into unaltered nephelite syenite, which it overlies. Amorphous ore is the least abundant. It is nonpisolitic and resembles clay, has no characteristic texture, and can be identified definitely only by chemical analysis. Uses of Bauxite Bauxite is chiefly used for, and at the present time is substantially the only

Jan 1, 1948

By D. S. Kingery, D. W. Mitchell

The authors attended the 11th International Conference of Directors of Safety in Mines Research held in France, July 1963. In addition to Conference discussions pertaining to control of coal dust they had the added assignment to study present European practices for neutralizing the coal-dust explosion hazard. Information was obtained through discussions with the Research Directors, by visits to testing stations and observations of operating mines in various countries. This paper tells what the current practice in this field is in Europe, and how effectively coal dust explosions are controlled. The method is rock dust barriers. CONTROL OF COAL DUST DISSEMINATION Experience in Europe indicates that the control of dust production and dissemination by water or foam systems is not successful except during undercutting. Cybulski, Dawes, and DeBraaf - respectively Director, Mines Research Establishment "Barbara", Katowice, Poland; Principal Scientific Officer, Safety in Mines Research Establishment, Sheffield, England; and Chief, Central Mines Research Establishment, Hoensbroek, Treebeek, The Netherlands - believe that wetted dust becomes readily dispersible and abatement measures should be considered only as a temporary means for reducing the health hazard. In an effort to reduce the health hazard, calcium chloride is used on the floor of main haulageways in Dutch mines and water infusion is practiced in Germany in mines where the coal is relatively porous. With respect to wet coal dust, the Belgians, British, Dutch, French, and Russians reportedly have accepted the results of research from the Polish and American experimental mines on the effectiveness of water as an inert in arresting explosion propagation. The Polish use the two test methods proposed by the U.S. Bureau of Mines1 for evaluation of the adequacy of wetness of mine dust; they require that water be added to the wet dust to maintain a minimum of 50% moisture by weight if dependence is placed on water alone. GENERALIZED ROCK DUSTING The general attitude with regard to protection against coal dust explosions throughout Europe is that generalized rock dusting is a vital primary step to inhibit initial ignitions but definite emphasis is also placed upon the efficiency of rock dust barriers. Those exceptions to generalized rock dusting are Germany and Austria where some rock dusting is done but principal reliance is placed upon rock dust barriers. The rock dust used in Belgium, Holland, Russia, and Poland is coarser than that used in the U. S.; 50% of the dust is through a No. 200 sieve (75 microns). Recent research by the Polish indicates that the portion finer than 20 microns is ineffective in arresting explosion propagation, and that the rock

Jan 1, 1964

Joseph William Richards, was born in Oldbury, Worcestershire, England, on July 28, 1864, of English-Scotch parents, Joseph and Bridget (Harvey) Richards. In 1871, he came to this country with his parents. He attended the public schools of Philadelphia, Pa., where his father was a manufacturing metallurgist, and in 1882, graduated from the Central High School with the degree of A. B. The same year he entered Lehigh University, from which he received the degree of A. C. (Analytical Chemist) in 1886; M. S. in 1891, and Ph. D. in 1893. His connection with the university was continuous from 1887 until his death, and he therefore adds another to the list of names of men Prominent in the A. I. 11. E. who have helped to develop Lehigh University to the important position which it now occupies in mining and metallurgical education in respect of world-wide fame. It is fitting to recall in this connection that, Eckley B. Coxe, a fonnder of the A. I. M. E., four times its vice-president,, and president in 1878-79, was literally a pillar of the university for several years prior to his death; Thomas M. Drown, founder, vice-presi(lent, secretary for 11 years, honorary member, and president in 1897, was president of Lehigh University from 1895 to 1904; and Henry S. Drinker, founder, manager, vice-president, and honorary member, was president of the university from 1905 to 1920. Doctor Richards was no less active in both institutions. With the exception of the years 1886 to 1887, when he was superintendent of the Delaware Metal Refinery of Philadelphia, his professional life was devoted to the upbuilding of the metallurgical department of the university, in part through his continuous services as a member of the teaching staff, and in part through the international renown won for the department by his achievevements as author, investigator, expert and rerognizcd authority in metallurgy, especially the metallurgy of aluminum, metallurgical-chemical calculations, and electrometallurgy. He was assistant instructor in metallurgy and blowpiping in 1887; instructor, 1888-90; instructor in metallurgy, mineralogy and blowpiping, 1890-97; assistant professor, 1897--1903; professor of metallurgy, 1903-1921. He died at his home in Bethlehem, Pa., on Oct. 12, 1921, of heart failure. To the A. I. M. E., for a continuous period of a dozen years, his services were equally loyal and effective. He was vice-president, 1910-11, and 1916-17; councilor, 1912; dirctor, 1913-15; chairman of the Iron and Steel Clommittee, 191-1-21; he was one of the framers of the Insti-

Jan 1, 1922

By A. D. Smigelskas, E. O. Kirkendall

THIS is the third paper in a series on the diffusion of zinc in alpha brass.1 At the time of the first-paper it was accepted that diffusion in a substitutional type of solid solution depended upon an equal interchange of solute and solvent atoms across the diffusion interface (or past a given lattice reference point). Discrepancies in the size of the areas under the diffusion curves on each side of the interface, if observed, were explained on some other basis than the fact that the solute atoms might cross the diffusion interface without an equal number of solvent atoms diffusing across the interface in the opposite direction. The second paper presented evidence indicating that zinc atoms in alpha brass diffuse across the interface more rapidly in one direction than the copper atoms diffuse across the interface in the opposite direction. This phenomenon forced the interface to move in the opposite direction of the diffusion of zinc atoms to provide space for the additional zinc atoms dissolved in the alpha brass. That the interface and columnar grain structure on one side would remain intact during this mass movement was not expected; however, it is gratifying that they did. While the evidence was sufficiently satisfying to the author, it was decided that additional experiments were in order to prove that zinc diffuses more rapidly than copper in alpha brass. It is the purpose of this paper to present the results of these experiments. PROCEDURE A bar of 70-30 wrought brass was selected, to avoid the relatively large volume change in going from beta to alpha brass as in the previous investigation. A bar 7 in. (18-cm.)* long and about ¾ in. (1.9 cm.) wide was surface ground and polished with abrasive paper on plate glass to 0.4184 ± .0002 in. (1.0625 ± 0.0005 cm.) thick. Six 0.005-in. (0.013-cm.) diameter molybdenum wires, chosen because of their very low solubility in copper and alpha brass, were stretched lengthwise along each of the two plane surfaces. Glass tubes placed at right angles to the wires every ½ in. held the wires tightly against the brass. The sample was then emersed in an acid copper sulphate plating bath and electroplated to a depth of about 0.020 in. (0.050 cm.) copper on all sides. The glass tubes were no longer necessary to hold the molybdenum wires in place and were removed. The sample was then electroplated to a depth of

Jan 1, 1946

By Clarence Zener

THE internal friction of nonferrous metals vibrating at low stress amplitudes has so far always been successfully interpreted in terms of inhomogeneities of one sort or another. Examples are the fluctuation of stress across a specimen vibrating transversely,1,2,3 the stress inhomogeneities due to the elastic anisotropy and partial random orientation of the individual crystallites,4,5 localized weak regions introduced by cold-working,6,7 grain boundaries and possibly twinning planes.8.9 Perfect single crystals are, by definition, homogeneous. Actual single crystals usually, perhaps always, contains some imperfections. The present investigation was undertaken to determine whether the internal friction of single crystals may likewise be attributed to inhomogeneities. This study was made possible through the gift of a large single crystal of 70-30 alpha brass by H. L. Burghoff, of the Chase Brass and Copper Co. The specimen, 3-s in. in diameter and 10 in. long, was similar to samples previously described by Mr. Burghoff.10 EXPERIMENTAL METHOD The experimental method used has previously been described in Institute papers.5,6.9 The measure of internal friction adopted here, I/Q, is (p) X the logarithmic decrement, a measure used by some writers, and is also (I/2p) X the specific damping capacity, a measure used by other writers. In all measurements the stress level was kept so low that the measurements were independent of stress level. In all measurements in which the temperature was varied, observations were made as the specimen slowly cooled from its highest temperature. The specimen was vibrated transversely. Observations were made at the fundamental frequency and at the first overtone, of about 620 and 1710 cycles per second, respectively. No attempt was made to avoid acoustical losses. EXPERIMENTAL RESULTS The specimen was annealed for several hours at 450°C. The temperature dependence of the internal friction was then determined from room temperature to 400°°C. As shown in Fig. i, the internal friction increased by only a factor of 2 from room temperature to 300°°C., then by a factor of 100 during the next :too' interval. These measurements are consistent with the view that the observed internal friction is the superposition of two distinct parts. One, dominant at room temperature, is nearly independent of temperature. This part may be accounted for by acoustical losses and by transverse thermal currents. It was not further investigated. The second part, when plotted in the manner of Fig. I, lies upon a straight line. Therefore it has a heat of activation H; i.e., it varies with temperature as Internal friction ~ e-HI/RT [I]

Jan 1, 1942

By Geo. H. Ashley

The following paper is intended to be suggestive only, and to open the way for discussion and further observation. Its preparation was requested only two days before the time limit set for the submission of the papers comprising this symposium. Thus no time existed for detailed studies, so it is largely a memorandum of such facts as have come incidentally to the notice of the writer in the study of coal in the field. The field study of sulfur in coal has received very little special attention or description from coal student's. The presence of sulfur concretions is noted in hundreds of descriptions, and certain benches of a coal bed may be described as "sulfury" or the presence and position of sulfur bands may be noted in coal sections in connection with sampling. It may be accepted that some sulfur is present in all coal. The amount varies greatly in different regions, in different beds, and in the same bed in different areas. The anthracite of Rhode Island comes the nearest of any coal known to the writer of being free from sulfur, several analyses of that coal showing less than 0.1 per cent. Subbitumi-nous coals in Colorado in a few places have close to 0.2 per cent. of sulfur on the dry-coal basis and in other states subbituminous coals approach this lower limit. Bituminous coals seldom run under 0.4 per cent. of sulfur on the dry basis, though in a few places dry bituminous coals in Colorado and Washington have between 0.3 and 0.4 per cent. The better known bituminous coals have almost everywhere over 0.4 per cent. The best of the Pocahontas and New River coals run close to 0.4 per cent., but there is very little commercial coal in Pennsylvania, Ohio, Indiana, Illinois, Kentucky, or the other states, that runs under 0.5 per cent. on the dry basis. From these minimum figures, the amount will range up to 5 or 6 per cent. or higher if visible sulfur is not excluded. It must be remembered that the usual analysis of a coal bed is not intended to give the total proportion of sulfur in the bed but the amount in the coal after the removal of the more obvious and larger sulfur masses. Professor Parr has already pointed out that, chemically, sulfur occurs in several forms: as pyrite, organic sulfur, sulfates, and possibly as un-combined sulfur. Sulfur in the form of sulfates is commonly the obvious result of the weathering of pyrite and may be found in the coal within .

Jan 1, 1920

By A. A. Smith

THE application of indium to bearings was first advocated by C. F. Smart1 in 1938, for the purpose of inhibiting corrosion of certain bearing alloys. He found that a thin layer of indium plated on the bearing surface and subsequently diffused at elevated temperatures markedly decreased the rate of corrosion in lubricating oils containing organic acids. Most of his work was done on cadmium-base alloys, although he showed that the treatment was also effective for copper-lead and other alloys. Since their introduction, indium-treated bearings have found considerable use, particularly in connection with airplane motors.2 Undoubtedly the effectiveness of the indium plate in resisting corrosion depends upon its relative concentration on the bearing surface after the diffusion treatment and after prolonged use at operating temperatures. Some diffusion experiments were made on a number of base metals that had been indium plated, to determine the depth of penetration after heating for reasonably long periods of time. As only the practical aspects were desired, no attempt was made to determine actual diffusion constants. METHOD Two different series of experiments were carried out to study the diffusion of indium into several base metals. Cast cylinders about one-inch diameter were machined to 0.750-in. diameter, so as to remove all surface imperfections, and final finishing was done with oo sandpaper. The original diameters were very carefully measured with micrometers and then a layer of indium was electrolytically deposited on the cylinders from a sulphate bath.3 In the first series of experiments, about 0.002 in. of indium was deposited and diffusion was carried out at 150°C. for a period of 500 hr. in a thermostatically con- trolled electric oven. After the diffusion period, successive layers were machined from the specimens and analyzed spectro- graphically and chemically-the spectro- graphic examination serving as a guide to determine which layers should be chemically analyzed. Apparently there was some surface oxidation of the indium plate due to the long heat-treatment, which may have had some effect on the diffusion. Also, the cadmium alloy showed some incipient melting, which probably was caused by the formation of a low-melting eutectic. To eliminate these factors, another series of experiments was carried out by heating in an electrically heated, automatically controlled, oil bath at lower temperature. The preparation of the specimens was the same as before except that a layer of indium 0.0001 in. thick, an amount commonly used commercially on bearings, was deposited on each of the cylinders. Diffusion was carried out at l20°C. for a period of 200 hours.

Jan 1, 1944

By John M. Gallow

Discussion of the paper of JOHN M. CALLOW, presented at the New York meeting, February, 1916, and printed in Bulletin No. 108, December, 1915, pp. 2321 to 2339. R. H. RICHARDS, Boston, Mass.-I think there is one note which would be interesting to have recorded in connection with this paper, and that is another form of flotation machine. The Minerals. Separation machine has a vortex action, with a vertical shaft and a propeller. This new frother has been developed for the Copper Queen Co. at Bisbee, Ariz. It has a horizontal shaft and a paddle wheel for a frother. It has eight cells, I think, all connected underneath in one continuous tank, and the only separation of the cells is in the upper chambers where the froth is. When this paddle wheel goes around it throws out the froth and the sand goes to the bottom and drifts over from the first to the second cell, where it is paddled again, and comes out with its froth; the sand goes to the third cell where it is again beaten. In that way the sand is continually drifting toward the last cell, while each new froth remains in its own cell. You can see in the working of this machine just the same effect that you see in Callow's machine, i.e., the earlier cell has the darker or richer froth, and the latter has the lighter or poorer froth until you get to the farthest one-which has very little froth, and is very light. JOSEPH W. RICHARDS, So. Bethlehem, Pa.-Speaking from the metallurgical standpoint, it is quite desirable, in many cases, that the oil be removed from the concentrate in order to facilitate the metallurgical work, and I think attention should be directed to the desirability of removing from zinc sulphide concentrates the oil which interferes with their subsequent roasting. The value of the oil is not large; in Mr. Callow's plant, for instance, it would be $20 a day, and it may be possible that a process might be developed which, within the limits of the value of the oil, would remove it, and thus facilitate the metallurgical treatment. LEONARD WALDO, New York, ,N. Y.-The question came up about a year ago as to why-Mexican crude was not an admirable oil for flotation. I have never heard any satisfactory answer to the question. The Mexican crude has the peculiar property of comparative freedom from dangers of fire, a very great reluctance to part with its water, and a specific gravity almost identically the same as water.

Jan 5, 1916

Discussion of the paper of G. Howell Clevenger and Bhupendranath Ray, presented at the New York Meeting, October, 1913, and printed in Bulletin No. 82, October, 1913, pp. 2437 to 2475. ALLERTON S. CUSHMAN,* Washington, D. C.:-I am very much interested in the subject matter of this paper. I have had occasion to speak to this question before. There has recently been so much written and said and claimed about the effect produced by the addition of small quantities of copper to steel that there is certainly an impression abroad that a new and wonderful cure-all has been discovered. Are we facing a method of alchemy by which, at the expenditure of very little trouble and only a few cents' worth of copper per ton, the well-known characteristics of steel with respect to some features are so marvelously changed as in effect to produce a new metal ? I am a great believer in the future of the iron and steel alloy field. I do not think that with all the advances we have made in metallurgy we have begun to scratch the possibilities of usefulness to mankind in the exploration of the alloy field, and I include in that alloy field even what might be designated as the dilute alloy field; that is to say, where a very small quantity of a metal alloyed with iron and steel confers upon it some new or extraordinary qualities. With respect to many of the physical characteristics of the copper-iron or copper-steel alloys I am not particularly competent to speak. With respect, however, to the investigation of corrosion problems and with respect to claims made with regard to resistance to corrosion, I am competent to speak insofar as I have specialized to some extent in that field and have given up a great deal of my time for a great many years to a study of it. Some years ago, being particularly interested in the study of corrosion problems, I received the very generous permission of a large manufacturing concern to use their large open-hearth furnaces any way I saw fit for exploring this particular field. There is not a metallurgist in this room who will not realize the generosity of a manufacturing company who would permit a man to pursue a theory and give him as his material to work with 60 tons of molten metal. At all events, I threw copper into the open-hearth furnace. I explored this alloy field, not in a ittle crucible in which I had to take out portions and have them

Jan 12, 1913

By Frank R. Milliken, Robert Goodwin

In September 1937, the Ohio Copper Co. inaugurated the treatment of its copper-bearing mill tailings at Lark, Utah. These tailings had been accumulated during the regular operation of the Ohio Copper mine and mill over the period 1907 to 1919. Gravity concentration had been employed except for a comparatively short period in 1919, when flotation was used. The ore milled during that period assayed about I per cent Cu. The chief copper mineral, chalcocite, was disseminated in a shattered quartzite, mainly along fracture or cleavage planes. The quartzite gangue was extremely hard and grinding to liberation resulted in excessive sliming of the "sooty" chalcocite, with consequent high tailings losses. Recovery on the seven million tons treated was probably less than 60 per cent of the total copper content. As early as 1918, attempts had been made to sample the dump. In 1928, a complete sampling program was undertaken. The sampling consisted of seventy-four 5-in. post auger holes drilled to the full depth of the dump at regular intervals of 250 ft. Each 10-ft. portion thereof comprised a sample for analysis. Each sample was screened, rolled, divided into three parts, dried and assayed. The reject was retained for testing purposes. From the depth of the auger holes a contour map of the dump was plotted, Fig. I, which gives percentages of tonnage and copper content. The tonnage within the limit of the drill holes was estimated at about five million tons with an average content of 0.42 per cent Cu, 31 per cent of which (0.13 per cent) was acid-soluble. A screen analysis of the composite dump sample is shown in Table I. Flotation tests by several companies and individuals were then made, the results of which ranged from 62 to 74 per cent recovery. On the basis of these, a 200-ton pilot plant employing straight flotation was built and operated for a few months. Operation of this plant was unsuccessful, as no provision had been made to handle the copper-bearing solutions resulting from the water-soluble copper, a point that was overlooked in the laboratory test work. Attempts to decant the copper-bearing solution for precipitation in the usual manner ahead of flotation were not satisfactory because of low water recovery (owing to poor settling characteristics of the pulp) and contamination of the copper precipitate with unsettled slime. Low copper prices in 1931 necessitated the termination of testing. With the stimulus of higher copper prices in 1937, a review was made of metallurgical

Jan 1, 1943

By C. W. Wark, Fred Wise

The Getchell mine, a comparatively recent gold discovery, is in the old Potosi mining district, Humboldt County, Nevada. All ore is mined from open pits using Diesel shovels and gasoline trucks. Two types of ore are mined, oxide and sulphide. Oxide ores are siliceous or shaly; sulphide ores either gougy, siliceous or shaly. In mining, the sulphide ore is segregated into hard and gougy ore, because the gouge must be dried before it can be crushed. The oxide ore is not segregated. General Metallurgy The oxide ore is the leached outcrop that overlies the sulphide ore body. All of the iron and arsenic sulphides found in the sulphide ores have been thoroughly oxidized. The sulphur and arsenic have been leached out while the iron is present as hematite and limonite. The oxide ore is amenable to direct cyanidation, and although no visible free gold is present it is released at a comparatively coarse grind. The sulphide ore is more refractory, since the gold is all of micron size and some of it is locked in fine sulphides. It has been established microscopically that the free gold is coated with an impervious shell, which is probably some form of iron compound. The sulphide ores contain from 1.5 to 2 per cent of arsenic, which is present as orpiment and realgar with minor amounts of arsenopyrite. The orpiment and realgar are of a later mineralization than the gold and are barren. Roasting and washing of the sulphide ore prior to cyanidation is necessary to eliminate , the arsenic, to alter the gold coating from an insoluble form to a soluble form, and to release the gold associated with the fine sulphides. Washing the ground calcine in weak sulphuric acid, trona, or hot water are beneficial in the order named, but to date the water is the best from an economic standpoint. Metallurgical tests as well as plant practice indicate that a certain amount of gold cannot be recovered even by going beyond economic practices. On this basis metallurgical results are viewed in the light of an optimum tailing rather than a percentage of extraction. Milling Practice Crushing (Fig. I).—There are three primary ore bins, one each for oxide ore, gougy sulphide ore, and hard sulphide ore. In front of each bin a substantial yard is maintained, which makes it possible to Stockpile 2500 tons of oxidized ore, 1000 tons of hard sulphide ore, and 1000 tons of gougy sulphide ore. The bins are fed by a 60-hp. caterpillar bulldozer from the stockpiles. Fig. I shows the method and

Jan 1, 1943

By Gerhard Derge, Arthur H. Grobe, Harold Markus

The high corrosion resistance possessed by tin under most circumstances, combined with its generally satisfactory appearance and useful physical properties, has led to many and varied uses for the metal. These uses have been partly limited by the fact that tin is an expensive metal, therefore many applications have been developed in which tin has been employed in combination with lead, either by coating, as in tin-lined collapsible tubes, or by the formation of alloys containing various proportions of tin-rich and lead-rich phases, as tcrne plate. A detailed knowledge of the corrosion characteristics of the tin-lead couple therefore is of general interest and has become specially important at the present time, when every effort is being made to conserve tin as much as possible. The present study has been limited to carbonate solutions with a pH range from 8.4 to 11.2 so that the results may be related to earlier work on the corrosion of tin and its alloys. 1-3,6 In these papers, the effects of a number of anion and cation additions to these solutions have been observed. Apparatus and Method The electrodes for the corrosion cell were cut from rolled sheet about 1/16 in. thick. The length of all specimens was held constant at 7 in., while the width was varied from M to 2 in. These electrodes were fastened to brass electrode supports, which were attached to rubber stoppers fitting into tall-type one-liter Pyrex beakers that contained the electrolyte. The lead electrodes were prepared from Omaha pig* and the tin was rolled from a slab of Chempur.† After cutting to size, the sheets were polished with No. I emery paper and cleaned with carbon tetrachloride. The edges, back and upper parts of the specimen were coated with a synthetic lacquer, which was supplemented with beeswax for the lead electrodes. The binding posts were coated with beeswax after the electrodes had been clamped. The pH of the electrolyte was controlled by adjusting the ratio of carbonate to bicarbonate. Approximately 600 ml. of electrolyte was used in each beaker. The entire assembly was placed in an oil bath thermostatically adjusted to operate at 30°C. + 0.1". Potentials were measured against a saturated calomel electrode connected to the cell by an agar-agar salt bridge. The carbonate solution used in the salt bridge was the same as that used in the corrosion cell. Currents were measured with a milliam-

Jan 1, 1942