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By H. S. Bell

IT SEEMS unnecessary to dwell upon the advantages of the modern pipe still as compared with the older type of distillation equipment used by oil refiners. The relatively low installation cost, coupled with remarkable operating efficiencies of pipe stills, precludes the consideration of other types except in rare instances where some peculiarity of product or plant may have an influence. The question of the actual heat required to distil petroleum is quite involved. We have extensive data on the latent heats of the various hydrocarbons under different conditions of pressure. We also have information regarding the specific heats of various oils and the effect of temperature thereon. Because of the complexity of petroleum and of each fraction, it seems impossible to theoretically analyze the partial-pressure effect of the great number of hydrocarbons upon one another during distillation. If a distillation curve and percentage analysis of any crude or product are available, it is possible to construct a curve with ordinates representing per cent. distilled and B. t. u. per pound or per gallon, or other desired unit. To do so the crude is split into fractions, of 5 or 10 per cent. The boiling point and gravity of each fraction being determined, it is possible to evaluate the heat required. As each fraction is removed, the residue must be raised to a higher temperature and latent heat supplied for the successive fraction. As the calculations progress, the latent heats decrease while the specific heats increase. Such a curve is illustrated by Fig. 1 for a typical 39.9 B° North Texas crude.

Jan 1, 1928

COMMITTEES. Iron and Steel. Albert Sauveur, Chairman. A. A. Stevenson, Vice-Chairman. Herbert M. Boylston, Secretary, Abbot Bldg., Harvard Sq., Cambridge, Mass. LOCAL COMMITTEES. Program Committee.-A. A. Stevenson, Chairman. Herbert A3. Boylston, J. E. Johnson, Jr., Henry D. Hibbard, E. Gybbon Spilsbury. Reception Committee.-J. R. Johnson, Jr., Chairman. Felix A. Vogel, William R. Walker. Dinner Committee.-E. Gybbon Spilsbury, Chairman. The opening session was held on Thursday morning, Oct. 16, 1913, at the Institute Headquarters in the Engineering Societies Building, 29 West 39th Street, New York, N. Y., and was called to order by President Rand, who addressed the meeting briefly before presenting Albert Sauveur, who responded to the President's address, and presided at the meeting. The following papers were then presented in oral abstract by their authors or authors' representatives: The Cleaning of Blast-Furnace Gas, by W. A. Forbes. Discussed by S. K. Varnes, H. N. Diehl, F. H. Wagner, Joseph Hartshorne, S. B. Marshall, J. W. Richards, J. E. Johnson, Jr., W. A. Forbes, and others.

Jan 12, 1913

By AIME AIME

THAT neither the Reconstruction Finance Corp. nor its subsidiary, the Metals Reserve Corp., are in competition with private enterprise was stressed by Charles B. Henderson in an informal talk before the N. Y. Section, A.I.M.E., on Sept. 23. Among other things, the speaker stated that the R.F.C., since its establishment, had authorized loans of $12,000,000, of which over $8,775,000 has actually been distributed. Of this amount, over $6,600,000 has been repaid. None of this money was appropriated by Congress, the sole assistance from that body being the initial authorization of $500,000,000 capital stock.

Jan 1, 1941

By W. H. Bassett

THE modern smelting and refining of copper is distinctly an American development. The present demand for sound and perfect castings for rolling is due to the development of American industry. Prac-tically every article made from sheet metal or, for that matter, from any form of metal is made by mass produc-tion methods. Faulty material disturbs the orderly sequence of operations and in addition requires expen-sive inspection and unbearable rejection of finished product. This demand, therefore, is positive and will have to be met. Some mines produce ore that can be smelted and re-fined without the electrolytic process into satisfactory copper for the wrought metal industry, and some of these ores carry small amounts of impurities that are of use in hardening and toughening the copper. Most of the copper ore mined contains impurities that must be removed and, fortunately, precious metals which are separated at the same time make this re-moval profitable. The modern electrolytic refineries have their methods so well under control that the product meets all re-quirements without question if properly fire refined and cast. The "if" in this case is important, because there is evidence of carelessness or want of control at times in the material from some of the producers. It is nec-essary that the melted cathodes should be saturated with oxide to dispose of sulfur and that the copper should then be poled to the proper pitch or set. Sometimes statements leak out to the effect that it is unnecessary to oxidize completely the molten cathodes and a little less rabbling saves poles, which are expensive. The re-sult is that the rolling mill gets porous castings and produces seamy or slivered sheets or strips. The condition of the molds, their temperature, and the temperature of the metal are all important to good copper cakes, wedges, or wire bars. Cracked, and burned molds leave rough places and porous spots. Molds which are out of shape, or cracked, make shrink-age cracks which gap open when the castings are hot-rolled. Dampness means porosity. Drops of oil mean porous or honey-combed areas. Poor or irregular dress-ing means mold wash in the castings. Cold copper or slow pouring means cold sets.

Jan 4, 1928

By H. C. Goodrich

At the Utah Copper mine, steam shovels were first used, in 1906, for the removal of overburden, and in June, 1907, for the mining of ore. Prior to 1907, the ore came from underground development work and from stoping. The use of the steam shovel gradually increased until 1914; since then all material, both overburden and ore, has been loaded by power shovels operating on the various benches of the mine. During these 19 years, there has been a great improvement in open-pit mining, largely in the use of equipment having greater capacity and dependability. The history of the development of mechanical shovels and related equipment, as affecting the Utah Copper Co., would be interesting and would justify considerable space; but of greater interest at this time is the operation of the equipment now in use. The Utah Copper mine is in a great deposit of copper-bearing monzo-nite, which occurs as a prominent headland of the Oquirrh range of

Jan 1, 1925

By G. H. Clevenger

THE reagents now used in flotation consist of various acids or salts, which may be either electrolytes or non-electrolytes, dissolved in water and some substance or combination of substances which function as collecting or frothing agents. At times the only dissolved salts present are those naturally occurring in the water used. The general effect of the electrolyte is to greatly sharpen the separation between the gangue and the concentrate. Examples of this are: The use of sulphuric acid with zinc ores; and of sodium carbonate or calcium oxide (line) with silver-gold ores. Crude pyroligneous acid is also sometimes used when available. Various oxidizing agents, such as permanganates, bichromates, etc., are added in the selective flotation of lead-zinc ores. Many other reagents for performing certain specific functions, either real or imaginary, have been proposed, and a number of them have been tried upon a working scale. The wild orgy of experimentation which is now going on in flotation exceeds even that which followed the introduction of the Washoe process for the treatment of Comstock ores, when, among other things, sage-brush tea and tobacco juice were reagents added to the pans. Out of all this will, of course, eventually come a more or less standard practice for the treatment of each class of ore. Omitting a discussion of the functions of frothing and collecting agents, the reagents used in flotation for this purpose may be classified under five general heads: (1) Essential oils; (2) fixed or fatty oils;. (3) alcohols and their combinations with organic acids; (4) coal tar and its refined products; (5) petroleum and its refined products. A flotative agent of some kind is required in flotation as now practiced. A single reagent, as, for example, certain. of the essential oils, may perform the dual function of frothing and collecting agent, or a mixture of substances may be required.

Jan 9, 1916

By John Hays Hammond

Discussion of the paper of John Hays Hammond, presented at the Chattanooga meeting, October, 1908, and published in Bi.-Monthly Bulletin., No. 24, November, 1908, pp. 1171 to 117S. PROF. HENRY Louis, Newcastle-upon-Tyne, En j. (communication to the Secretary'`) :-I welcome Mr. Hammond's paper as an. attempt to give definiteness to the best modern professional practice. Such a codification of our professional ethics is urgently needed, seeing how widely the views of mining engineers differ on some of the point-,. raised, for example, I have no hesitation it) performing a class of work, as to which Mr. Hammond seems to entertain some doubts, and, on the other hand, I strongly condemn a practice which he appears to recommend. I have not the least hesitation in making reports for vendors of mining properties, and am constantly doing so; . the best justification for this practice may be found in the fact that such reports have been repeatedly accepted by buyers as giving a correct representation of the facts of the case, which is all that should be demanded from any report. On the other hand, Mr. Hammond advocates that mitring engineers should take payment for their reports tin shares of a company to be floated upon the basis of such reports. I hold that this is ethically wrong, as even the most honest of men is liable to be unconsciously biased under these conditions. Indeed, I go much further, and maintain that a mining engineer who re¬ports or advises upon mining properties should never hold any-mining shares at all, or be himself interested in any mine,' and this has been my consistent practice for many years. A man who holds shares in a mine, and is called upon to report upon a neighboring property or a similar mine, can never be wholly unbiased, and even if lie could be, he would always lay himself open to the suspicion that he was giving a favorable report so as to-enhance the value of the property in which he himself is interested, or an unfavorable report so as to stifle competi-

Jun 1, 1909

Jan 1, 1968

Jan 1, 1968

By C. D. Thurmond

Jan 1, 1968

By D. W. Jessup

THE handling of native labor is offering an interesting problem that requires diplomacy. It is difficult to induce many of the men to leave their villages and enter into regular work. They do not feel the necessity of manual labor other than to obtain sufficient money to pay the annual hut tax and to buy a little clothing. The ground provides mealies (corn) which means food and beer, he hunts and catches fish, so why work? But gradually, as the native becomes more civilized, his wants increase and his ideas change; he now needs money to supply his desires and eventually he must work more. So in time it is hoped that the labor market will be better supplied.

Jan 1, 1931

By F. O. Garrabrant

POWER is furnished to the Climax Molybdenum Co. by the Public Service Co. of Colorado over two 100,000-volt line to a bank of three 3333-kva. Transformers 100/13.8 kv. These transformers arc so designed that with the addition of forced cooling their capacity may be increased 33 1/3 per cent at 12,000-ft. altitude. Under present conditions, these transformers are operated at 140 per cent of their rating with forced air cooling. On the secondary side of this bank there is a 15-kv., 1200- amp. Westinghouse oil circuit breaker provided with automatic reclosing relays allowing three successive short circuits before lockout. From this breaker 13.8-kv. power is transmitted to a central switching station (Fig. I) where all circuits radiate to the different operations of the property. Each circuit is protected by a 23-kv., 600-amp. oil circuit breaker with by-pass and isolating disconnecting switches. MINE Power at 13.8 kv. enters the mine through a ventilation raise over a three-conductor, size 1-0 varnished cambric insulated, leaded, steel-wire armored cable, insulated from 17 kv. This power is received and distributed through one switching station and four underground substations, shown in Fig. 2. No. 370 substation (Fig. 3) contains three 250-kva, 13,800/440-volt, single-phase Pyranol transformers protected on the high-voltage side by a 600-amp. manually operated oil circuit breaker. This station serves 20 slusher-hoist motors, a 45-kw., three-phase, 220-volt electric furnace, a Massco hot miller for tempering and milling Timken detachable bits and a hoist with 175-hp. motor on the No. 3 development shaft. Also at this shaft are three pumps. One two-stage pump, 1200 gal, per min., 100-ft. head, 3600 r.p.m., driven by a 150-hp. motor, is at the bottom of the shaft. Two deep-well pumps, 500 gal. per min., 500-ft. head, are at the collar of the shaft. Under normal operation the one pumping 1200 gal. per min. is controlled by a float switch to take care of the water. If this pump fails, or if its capacity is insufficient, the first 500-gal. pump is automatically started, and if still more capacity is needed the second 500-gal. pump automatically starts. Time delay relays are provided on the deep-well pumps, so that if power fails the column will have time to drain before the pumps restart. On failure of any of these, an alarm is sounded in the train dispatcher's office, so that mechanics can be sent to ascertain the cause of failure and make repairs. The cable from No. 370 substation is run to the switching station, in which are four15-kv., 600-amp. direct-current solenoid-operated oil circuit breakers. The current for operating and tripping is furnished by a 125-volt storage battery. All breakers are operated from the switchboard in the compressor room. One circuit from this switching station goes to the

Jan 1, 1944

By Charles T. Baroch, Charles J. Baroch

Nuclear energy probably has greater potentialities for changing the world's way of life than any other recent discovery. The atomic-bomb bursts over Hiroshima and Nagasaki suddenly changed the concepts of war. Peaceful uses of nuclear energy are advancing so rapidly that no study of economic trends is complete without giving them consideration. The minerals specialist, especially, must be aware of this new force in our lives, as minerals and metals are essential in harnessing the new force, and atomic energy itself is rapidly improving its competitive position in the energy field. Future historians may chronicle December 2, 1942, as the beginning of the Atomic Age. On that day Enrico Fermi and his co-workers at the University of Chicago produced and controlled the first self-sustaining nuclear chain reaction. Lie many inventions, the first application of nuclear energy was as a weapon of war. However, its potential usefulness in man's work and welfare far outweighs in economic importance its destructive use in war, unless its military effect would be considered so great and all-embracing that no major power will hereafter chance a world conflict. Recognition of this potential has generated a vast international effort to exploit the atom for peaceful beneficent purposes. Like its physical manifestation, the advent of nuclear energy has unleashed chain reactions that have pervaded the political, social, and economic environments of the world. The impact of nuclear developments in one of many fields is exemplified by the uranium mining industry. Uranium was discovered in 1789 and in the next century and a half it found only an insignificant use as a ceramic coloring agent; in fact, in the latter part of that period, it was a largely unsalable by-product of the radium and vanadium industries. Up to 1940 the total quantity of uranium metal produced was not more than a few grams, of doubtful purity. Thus the production of 12,400 pounds of pure

Jan 1, 1964

By George S. Rice

GROUND movement from mining, whether it be for coal, metal, industrial minerals, or .oil, will always present many difficult problems. These are especially serious when valuable surface improvements may be badly damaged. The mine itself, if mining methods are not suitable to the formation, is subject to heavy falls of the main roof in the working places; and with certain structural conditions the movements may cause in coal mines disastrous bumps and outbursts of gas, and in deep metal mines rock bursts. In open-cut work rock and earth slides may result. Absolute prevention of ground movement from mining is impossible unless large pillars are left unmined,

Jan 1, 1937

By George M. Fowler

MINING geology is a progressive study, so we must look to the future for the solution of many of its most significant problems. These problems, world-wide in scope, offer ample opportunity for the exercise of the utmost skill and intelligence by all that attempt to solve theta, as it is generally recognized that many ore deposits of the future will he found only by months or years of combined intelligent effort by the several engineering groups. Renewed appraisals are continually being made to better understand the relationship of physical-chemical processes to ore deposition and other mineralization and to interpret the findings of the geophysicists and others in terms of economic results. A study of current geologic activi¬ties clearly reflects the growing tendency for cooperation between the different branches of geology in order to appraise their united efforts. In line with these activities arrangements have been made to transfer the geophysical section of the U. S. Bureau of Mines to the Geological Survey.

Jan 1, 1936

By E. I. Larsen, A. S. Doty, F. R. Hensel

The alloy under discussion is a Pig. I shows results of heat-treating tests nickel-silicon bronze and is one of many on two typical nickel-silicon bronze castings age-hardening or precipitation-hardening of the type on which the observations were copper-base alloys. The hardening constituent is a nickel-silicon compound.l The quenching temperature necessary to produce hardening by a subsequent aging treatment is a function of the composition and extends from about 700°C. to 950°C.; the aging temperature range extends from 4000 to 600°C. The work carried out by the authors of this paper was confined to cast alloys having compositions within the ranges of: 1.5 to 3.00 per cent Ni; 0.4 to 0.75 per cent Sj: balance. comer. made. A quenching temperature of 750°C. produces almost as high a hardness on subsequent aging as do quenching temperatures of 850' and 900°C. Several foundries have spent years of active and intelligent effort in trying to control the casting and heat-treating variables of nickel-silicon bronzes and finally gave up the attempts because of the inconsistencies of results.2 This undesirable characteristic was not manifest in the ultimate hardness or conductivity but primarily in tensile strength and ductility, as shown in Table I. The variation in tensile properties was often much greater than that existing on the alloys

Jan 1, 1941

By A. S. Doty, E. I. Larsen, F. R. Hensel

The alloy under discussion is a Pig. I shows results of heat-treating tests nickel-silicon bronze and is one of many on two typical nickel-silicon bronze castings age-hardening or precipitation-hardening of the type on which the observations were copper-base alloys. The hardening constituent is a nickel-silicon compound.l The quenching temperature necessary to produce hardening by a subsequent aging treatment is a function of the composition and extends from about 700°C. to 950°C.; the aging temperature range extends from 4000 to 600°C. The work carried out by the authors of this paper was confined to cast alloys having compositions within the ranges of: 1.5 to 3.00 per cent Ni; 0.4 to 0.75 per cent Sj: balance. comer. made. A quenching temperature of 750°C. produces almost as high a hardness on subsequent aging as do quenching temperatures of 850' and 900°C. Several foundries have spent years of active and intelligent effort in trying to control the casting and heat-treating variables of nickel-silicon bronzes and finally gave up the attempts because of the inconsistencies of results.2 This undesirable characteristic was not manifest in the ultimate hardness or conductivity but primarily in tensile strength and ductility, as shown in Table I. The variation in tensile properties was often much greater than that existing on the alloys

Jan 1, 1941

By P. G. Shewmon, H. E. Collins

We have studied the effect of adsorbed sulfur on the surface self-diffusion of copper using eight diflerent surface orientations and the grain boundary grooving method. The eight orientations studied were the four lying near the low-index surfaces—(loo), (Ill), and two directions in the (110)-plus four higher-index surfaces. Surface-diffusion measurements were made over a range of HZS concentrations (in Hz) from 3 to 1500 ppm between 830°and 1050°C. The results can be divided into two groups—Group 1 contains the two (110) surfaces while Group 2 contains the remaining six surfaces. In Group 1, increasing the temperature increases the effect of Hz S on DS for the Hz S range 5700 ppvn. Qs and Do increase with increasing H2S concentration in this Hz S range. Beyond this range, increasing the temperature decreases this effect on D,; also Q, and Do decrease. In Group 2, increasing the telnperature decreases the effect of H2 S on D, for the H2S range studied, and Qs and Do decrease with increasing Hz S concentration. In any study of surface phenomena, there invariably arises the question of the possible presence of and effect of adsorbed impurities. Such questions are well-founded since the presence of adsorbed atoms can sometimes produce marked changes in the kinetics of surface-energy-driven processes. In the last few years, values of the surface self-diffusion coefficient, D,, have been determined on a variety of metals by studying the decay of scratches or the growth of grain boundary grooves.L~3-L0~L3 Yet there has been relatively little work done in which the concentration of an adsorbed impurity was systematically varied and the effects observed. Work of this sort would provide some basis in fact for the assertions often made about the ro1.e of adsorbed impurities in the differences between the results of different workers in different atmospheres and on different metals. It also is relevant to those cases in which surface monolayers produce profound effects in commercially important processes. The most marked example of such effects is the ability of nickel or palladium to increase the sintering rate of tungsten by many orders of magnitude.' The aim of this work was to study the effect of sulfur partial pressures on the surface self-diffusion of copper. It was felt that this in conjunction with a study of the degree of adsorption and type of active sites involvedL8 would provide a wide range of data for one system and hopefully lead to some insight into the mechanism by which sulfur adsorption influences copper diffusion. The main reasons for choosing the Cu-S system were, first, faceting was reported not to accompany the adsorption of sulfur. This is required if our experimental technique is to work. Second, Oudar has determined a high temperature adsorption isotherm for this system, an event which puts the Cu-S system almost in a class by itself.I4 EXPERIMENTAL PROCEDURE Initially, we considered studying the effect of an adsorbed impurity on surface self-diffusion of copper using isolated (or single) scratch smoothing as the technique and oxygen as the impurity. Copper was chosen as the material because the effects of orientation and anisotropy of the surface self-diffusion coefficient, D,, of copper in a dry hydrogen atmosphere had been studied extensively by Gjostein' and by Shewmon and ~hoi.~,~ The isolated scratch technique was chosen because both the effects of surface orientation and anisotropy of D, in a given surface could be easily studied with this method.~ Oxygen was tried as the impurity because Robertson and Shewmon""~ had studied its adsorption on copper at 1000°C over the range of oxygen partial pressures of 10"22 to 10-l3 atm. After several preliminary runs, it became evident that neither the scratch technique nor the impurity oxygen would be satisfactory for this work. Scratching deforms an annealed surface so that the region near the scratches recrystallizes, thereby disrupting the scratch profiles. One can avoid this by deforming the specimen sufficiently before scratching to give complete recrystallization on subsequent heating.4 However, as a result of Gjostein's success in scratching and annealing undeformed gold single crystals without local recrystallization,13 we attempted something similar with copper single crystals using a 0.7-mil diamond phonograph needle mounted in a Tukon hardness tester. All specimens recrystallized upon being annealed. Also, some copper specimens were sent to Gjostein to be scratched using his technique. The results were the same. As a result, the scratch technique was dropped in favor of the grooving of symmetric grain boundaries. Preliminary work using oxygen showed that faceting began to occur before oxygen adsorption had any measurable effect on D, at 938°C (at Pbo/P, = 0.12). Since heavy faceting would interfere with the measurement, we decided to use a sulfur-containing atmosphere (H2S/H2). Work by Oudar and Benard' and Robertson" showed that sulfur absorbed on copper and that faceting was not observed.

Jan 1, 1967

By W. P. Sykes

Seven years ago, Dr. S. L. Hoytl presented a masterful discussion of the hard metal carbides and cemented tungsten carbide. His lecture summarized most of the data then available in the field; many of the details relating to the production, properties and structure of cemented tungsten carbide had never been previously published, for, in fact, this information was only then being acquired. During the intervening years, the cemented carbides have assumed a place of real importance in the commercial field, with an ever widening variety of applications due to constant improvement in the control of production technique and the unremitting search for new compositions that might better the performance of the alloys in one or another type of service. The most recent summary of production methods, properties and guides for the successful application of the cemented carbides appears in the 1936 edition of the Metals Handbook. Of necessity, much detailed information relating to structures and physical properties is not included in such a summary, and it is with such details that the present discussion is concerned. Steps in Preparation While the past 25 years have contributed a valuable store of working knowledge in the field of powder metallurgy, many of the process controls are derived entirely from experience and are not as yet finally explained by a specific physical or chemical phenomenon. For most of the cemented carbides such difficulties are aggravated by our lack of knowledge not only of the complex alloy systems involved, but also by the possible changes in structure and even in composition which may accompany variations in temperature, heating time, and furnace atmospheres. The principal steps in the preparation of these cemented carbide alloys are fairly well known, but to supply a foundation for discussion these steps are briefly outlined as follows : 1. Formation of the metal carbide in the form of powder by heating a mixture of carbon and the metal powder or oxide for several

Jan 1, 1938

By W. P. Sykes

Seven years ago, Dr. S. L. Hoytl presented a masterful discussion of the hard metal carbides and cemented tungsten carbide. His lecture summarized most of the data then available in the field; many of the details relating to the production, properties and structure of cemented tungsten carbide had never been previously published, for, in fact, this information was only then being acquired. During the intervening years, the cemented carbides have assumed a place of real importance in the commercial field, with an ever widening variety of applications due to constant improvement in the control of production technique and the unremitting search for new compositions that might better the performance of the alloys in one or another type of service. The most recent summary of production methods, properties and guides for the successful application of the cemented carbides appears in the 1936 edition of the Metals Handbook. Of necessity, much detailed information relating to structures and physical properties is not included in such a summary, and it is with such details that the present discussion is concerned. Steps in Preparation While the past 25 years have contributed a valuable store of working knowledge in the field of powder metallurgy, many of the process controls are derived entirely from experience and are not as yet finally explained by a specific physical or chemical phenomenon. For most of the cemented carbides such difficulties are aggravated by our lack of knowledge not only of the complex alloy systems involved, but also by the possible changes in structure and even in composition which may accompany variations in temperature, heating time, and furnace atmospheres. The principal steps in the preparation of these cemented carbide alloys are fairly well known, but to supply a foundation for discussion these steps are briefly outlined as follows : 1. Formation of the metal carbide in the form of powder by heating a mixture of carbon and the metal powder or oxide for several

Jan 1, 1938