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Seattle offered sunny, dry weather to about 2500 mining men who assembled September 10 to 14 for the 1961 American Mining Congress. The impact of snappy sessions on national mineral policy, state of the industry and foreign competition (to name only a few) was somewhat overshadowed by enthusiasm of conventioners for salmon fishing. This lordly fish, which mysteriously runs to its hatching place to spawn and die at this time of year, was not cooperating with the anglers in Puget Sound. However, this did not prevent consuming ample amounts of the deliciously prepared Quinault salmon at the "Potlatch" celebration.

Jan 10, 1961

By William B. Plank

STATISTICS just released by the American Society for Engineering Education and given in the table, show that the total current enrollment of 200,227 in the 220 engineering schools of the U. S. and Canada represents a gain of 9.8 pct over a year ago, while the mineral engineering enrollment in the U. S. of 9826 shows a gain of only 4 pct in that field. The spurt in the mineral group shown last year is thus slowed down to less than one half of that in the whole engineering student body. Last year, it was growing more rapidly than the whole engineering group.

Jan 5, 1954

By L. Moyd, P. Moyd

The first commercially available portable gamma ray-neutron beryllium detector, the Rerylometer, was developed by the same group that developed the first practical portable scintillation counter, the Scintillo-meter. This group includes Professor George Brownell, of the Geology Department of the University of Manitoba in winnipeg, and his associates, K. I. Roulston, R. w. Pringle, and R. L. Funt, of the Physics and Engineering Departments of the University of Manitoba. A prototype model was tested in the field by Dr. Brownell during the summer of 1958. Commercial production was undertaken shortly thereafter by Nuclear Enterprises Ltd., of Winnipeg, and a license for manufacture and distribution in the U.S. was granted to Isotopes Specialties Co., of Burbank, California, a division of Nuclear Corporation of America. Early in 1959, we were retained by the 'Mining Division of Minerva Oil Co. to Legin a search throughout North America for minable deposits of beryllium, and to train members of their permanent staff to continue the program. The project included literature sur-veys, interviews with members of various federal, state, and provincial agencies, scanning of our own collection of suites of specimens from various mineral occurrences, and the examination of deposits in the field. The value of a beryllium detector to this program was obvious and arrangements were made to procure one as soon as possible, which resulted in our obtaining and using the first instrument that was produced commercially in the U. S. In addition to the commercially available Berylometer, Mr. William Vaughan and his associates, of the U. S. Geological Survey Geophysics Division, in Denver, have developed and tested several experimental instruments based on the same principles. DETECTOR Principles The detection of beryllium is based on the fact that "hard" gamma rays (1.6 MEV and geater), such as those produced by Antimony convert ordinary beryllium (Be9) to Be8 , with the release of a neutron. The neutrons are counted by a scintillator designed to favor neutron responses while suppressing those of gamma rays. 'The instrument is completely selective for beryllium. No other element can interfere. Instrunlentation The Rerylometer itself, which is cylindrical, is about 8 inches in diameter, 13 inches high, and weighs about 11 pounds. (Figs. 1, 2). The principal components include: 1. A disc of wax to moderate (or "thermalize") neutrons. 2. A boron-enriched polyester-zinc-sulphide fluorescent screen. This material produces strong flashes when struck by thermalized neutrons but only weak flashes from gamma rays. 3. A photomultiplier tube. 4. An electronic circuit, complete with one srnall 71/2-volt dry battery. The photomultiplier tube and electronic circuit convert neutron flashes to electrical impulses, but gamma ray effects are almost

Jan 1, 1961

By Fred H. Perfect

The thermite process, now approximately 80 years old, has heretofore been practiced in ceramic vessels. This paper outlines the successful production of several million pounds of alloy produced in zuater-cooled copper vessels. THE high temperatures necessary to produce fluid high-alumina slags have probably discouraged earlier workers from attempting to utilize water-cooled vessels. The following is a report of the successful application of this method, together with a report of the physical and chemical problems which had to be solved to make the process practical. About 1955, when Reading Alloys was more concerned with the production of ferrotungsten than with most other types of alloys, it was found to be exceedingly difficult to predict the reaction rate that one would experience from one tungsten ore to another . This difficulty was increased for two reasons: the physical state of the ore as received was seldom uniform, and the size of the mass to be reduced is a very important factor in developing the proper mix for the final reaction rate and temperature. For example, the reduction of ferric oxide with aluminum would theoretically produce temperatures of about 2600°C, and, in spite of the losses due to radiation, the energy is quite sufficient to produce a very fluid slag and iron effecting a very clean separation. On the other hand, the reduction of ferrous oxide with aluminum, while it is not as energetic as the first reaction, nevertheless should give temperatures above 2000"C, which should cause separation of alumina and iron, but, in practice, this is not the case and good fluid slag is not obtained. The heat of reaction, calculated from the thermo-dynamic heats of formation of the constituents of the reaction, offers a convenient guide to the feasibility of a thermite reaction. Thus, the values listed in Table I can be used as an approximate guide for estimating the results which may be expected in the reduction of various oxides and combinations of oxides using aluminum as the reducing agent. As a generalization, those reactions releasing approximately 600 cal per g of total mass represent the lower limit at which to expect separation of slag and metal. On the other hand, those reactions which release 1100 to 1200 cal per g are too violent to be used successfully without the addition of considerable inert material, such as lime, fluorspar, and so forth. Reaction rate is also a very important factor. This, of course, is governed very largely by the sizing and intermingling of the oxidant and reductant and by the starting temperature of the reactants. This is why those figures shown in Table I can only be a general guide. Further, it must be understood, that by adding powerful oxidizing agents, such as nitrates, chlorates or metallic oxides, such as molybdenum trioxide or chromium trioxide, certain problems respecting low temperatures are not necessarily solved. This is true in the addition of oxidants, such as sodium chlorate. By adding too high a concentration of sodium chlorate as a booster for a particular reduction, explosions are generated. Generally, they are of an intermittent type so as to give a Roman Candle effect to the reduction itself; with each surge resulting from a minor explosion more and more material is thrown

Jan 1, 1968

Accessions AMERICAN ELECTROCHEMICAL SOCIETY, TRANSACTIONS, vol. 33. Bethlehem, Pa. 1918. AMERICAN ASSOCIATION OF PETROLEUM GEOLOGISTS, BULLETIN, vol. 2. 1918. (Gift of the Association.) AMERICAN YEAR BOOK: 1915. Edit by Francis G. Wickware, New York. 1919. (Gift of D. Appleton & Co.) ANNUAIRE DE LA HOUILLE BLANCHE FRANCAISE. ` By M. Auguste Pawlowski. 2d year. 1918-1919. Paris. (Gift.) BLACK DIAMOND, Vol. 60, Jan.-June, 1918; vol. 61, July-Dec., .1918. (Gift.) Chicago. CANADIAN MINING INSTITUTE, TRANSACTIONS, vol. 21. 1918. Montreal, Quebec. COMPTES-RENDUS DE L'ATHÉNÉE LOUISIANAIS, vol. 4, No. 3. (Gift of Wm. Beer.) EFFICIENCY OF NATURAL GAS AT Low PRESSURES. Abst. of testimony of Samuel S. Wyer before the Corporation Commission of Oklahoma, February 4, 1919. Printed by Empire Gas & Fuel Co., Kansas City, Mo. GEOLOGICAL. INSTITUTION OF THE UNIVERSITY OF UPSALA, BULLETIN. Edit. By Hj. Sjögren. vol. 14, 1917; vol. 15, 1916; vol. 13, pt. 2, 1916. (Gift.) HYDROGENATION OF OILS. Catalyzers and catalysis and the generation of hydrogen and oxygen. By Carleton Ellis. 2d edition. New York. 1919. (Purchase.) INSTITUTE OF METALS, JOURNAL, vol. 26. No. 2. Edited by G. Shaw Scott. London. 1918.

Jan 6, 1919

By John H. Schissler

INTRODUCTION AND SUMMARY Complex copper-lead-zinc ore is mined from underground workings high in the Western Cordillera of the Andes mountains about 100 km in a stralght line north of the city of Arequipa in southern Peru. The Madrigal mine is situated in a steep-walled canyon into which the six operating levels "daylight". Production is from cut-and-fill stopes currently producing approximately 740 dry metric tons per day. The Santa Rosa vein, the most important producer in the district, outcrops for a distance of about 4 km, bearing N 75º W and dipping about 70º NE. In places the vein splits into two or three branches; widths of each vary between 1 and 4 m and total mineralized widths of up to over 8 m occur. Principal ore minerals are chalcopyrite, galena and sphalerite. Ore reserve grades for the Madrigal mine average about 1.45% Cu, 2.6% Pb and 5.0% Zn, 2.9 ozAg per metric ton. [Compania] Minera del Madrigal is a California limited partnership; the general partner and operator is [Compania] Madrigal, a wholly-owned subsidiary of Homestake Mining Company. HISTORY Shallow workings found on the Santa Rosa vein were probably made by the Spaniards during colonial times in their search for

Jan 1, 1977

By Edmund M. Warner

Any city dweller who has walked alone along a remote mine passageway has to be impressed by the eerie silence-the total absence of noise except for one's own breathing and scuffing of boots on the bottom. An underground mine can have tremendous contrasts, from complete silence to the ear piercing clatter of percussion drills working in the mine roof. Noise in underground mining machines is both useful and detrimental. Without characteristic noises that are recognizable to miners, operators would have a more difficult job operating their machines. Noise serves as a warning of approaching machinery, and changes in noise give indication that breakdowns may occur.

Jan 1, 1979

By Maurice Grieves

The great majority of shafts constructed today are still excavated by drilling and blasting, a method which changed very little in over 100 years until the introduction of the mechanical lashing unit and cactus grab by the South Africans, which enabled muck to be removed as fast as massive hoisting systems could handle it and resulted in very rapid rates of sinking. Record breaking month's performances were achieved at -Hartebeestfontein No. 4 shaft, October 1960-337.1 m; Western Reefs No. 4 shaft, October 1961-340.7 m; and Buffelsfontein eastern twin shaft, March 1962-381.2m. The method was very labor-intensive, requiring a crew of over 60 workers at the shaft bottom during the drill cycle. Safety precautions were strict, but in the drive to achieve rapid advance, cases of personal injury were still somewhat high because of the large number of people engaged in this potentially hostile environment. The South African method, as it came to be referred to throughout the rest of the world, was adopted in the United Kingdom in the late 1950s in a modified form with greatly reduced manpower and nonsimultaneous sinking and lining, which was insisted on by the British Mines Inspectorate. In that instance, it was successfully used to sink the 7.3-m-diam concrete-lined shafts at Kellingley to 770 m depth, with rates of advance of over 90 m/month achieved, a British record at that time. During the sinking of the 1.15-km-deep twin shafts at Boulby potash mine in the UK in 1970, the method was again used, but for the first time ever in Britain exemptions from the mining code permitted the use of crash beams, crash doors, jack catches, and semi-simultaneous sinking and lining techniques. New British shaft sinking records of over 120 m/month were achieved in both shafts. Similar equipment and techniques were used in the early 1970s to sink several deep shafts in Canada, notably Creighton #7 and the Con zinc mine at Yellowknife in the NW Territories. Today, this equipment is standard for deep shafts in the US and the rest of the world. However, with the tremendous escalation in mining labor costs, the impact of health and safety legislation, and environmental regulations, coupled with a very real shortage of miners willing to work in this exposed situation it was apparent that an alternative to the labor-intensive conventional method of shaft construction had to be found. Recognizing the trend is inevitable, one or two major German shaft sinking contracting firms began to take a fresh look at full face boring techniques applied to tunnels and raise bored shafts. The results were most encouraging. Tunnel drivage techniques using moles had developed considerably from Colonel Beaumont's original channel tunnel machine circa 1880 to the superbly engineered Priestley machine selected to cut the British side in 1975 and the double shielded Robbins Grandori borer on the French side of the English Channel. Full face tunnel machines were being successfully used to drive uphill in inclined shafts in Austria and Switzerland. At Mapprag in Switzerland, the Demag mole drove the first (intentional) vertical transition and curve, and then went on to successfully complete the 730-m-long penstock shaft at an inclination of 35°. In Austria, the Wirth mole drove the Kaprun Glacier ski-lift railcar tunnel at record breaking rates of 457 m/MONTH (best 30 m/d) through green schist at an inclination of 29° for a distance of 3.35 km while the Hydro tunnel at Sarrelli in Switzerland was being driven by the Robbin's mole at an inclination of 35°. Simultaneously, extremely promising results were obtained using large assemblies of cutter discs on raise borer heads, such as the 4.87-m-diam X 460-m-deep shaft raised by Teton for Jim Walter Resources Inc. Bearing in mind that most mine shafts in the future (unless in exceptionally competent rock) will require some form of lining, and the trend will be toward deeper shafts as the more easily accessible mineral deposits become exhausted, it was seen that normal raise boring had definite limitations in vertical accuracy, in the limitation imposed by the drill string on the available torque that could be applied to the cutter head, and in the risk of collapse of the unsupported shaft rock wall in friable or jointed and fissured ground, since it is not possible to apply any form of temporary support until the permanent lining is being installed. A further problem was the economics of installing a subsequent lining, necessitating setting up a headgear and hoisting arrangement approaching in size that required for conventional drill and blast sinking and lining. Because of the economics, German contractors opted for a phased transition from drill and blast to the full face, rodless, out of the solid shaft mole, by starting off with a down-the-hole shaft boring machine -without a drillstring-but using a pilot hole to get rid of the muck.

Jan 1, 1982

By W. A. Backofen, D. H. Avery, G. A. Miller

An evaluation has been made of the relative importance of yield strength (?) and stacking-fault energy (y) to the rate of fatigue-crack growth in materials of fcc structure. Pure copper and its solid-solution al-loys with aluminum and nickel were chosen for the study because they provided sufficient range in both quantities of interest that either could be varied independently of the other. Experiments involved alternating tension and compression of flat specimens which were prepared with sharpened internal notches so that most, if not all, of the crack-nucleation interval could be eliminated. Growth rate (dC/dN) was concluded to be proportional to the square of the plastic-strain amplitude (€,,) over a strain range of approximately 6x 10-4 to 6 x 10-3. The factor, k, linking dC/dN and ep in dC/dN = kEp2 increased and decreased with corresponding variations in y, but it did not respond syste?>/atically to change in ay, indicating that y is the significant variable in crack growth at constant plastic-strain amplitude. In polycrystalline material, k varied by a factor of 5 over the available range of y. In a few single-crystal experiments on Cu-A1 alloys the growth rate responded less strongly to change in y. It has been suggested that single crystals behave somewhat differently than poly crystalline material because there is more extetnsive substructure near the grain boundaries in the latter, and this facilitates crack advance by separation along subgrain boundaries. A point of some controversy in current work on fatigue relates to the effects of strength and stacking-fault energy on crack growth. In recent experiments a separation was made between the cycling intervals for crack nucleation and the subsequent growth that eventually ends a specimen's fatigue life.' The study was carried out on Cu-A1 alloys primarily, fatigued in alternating four-point bending to constant deflection. A nucleation interval of about 10' cycles (at a total strain amplitude = 0.2 pct) was found to be insensitive to aluminum content in the range 0 to 7.5 wt pct, while the growth period was increased approximately forty fold over the same compositional range. The increase was not in any sense linear, however. Rather, most of the change occurred below 4 pct A1 or a stacking-fault energy, ?, of about 15 ergs per sq cm. It was argued that the plastic-strain amplitude was approximately constant, and therefore the effect of composition must have grown out of the reduction in stacking-fault energy. Several studies have shown that, with high ?, cross slip is encouraged, subgrain structure is introduced during fatigue, and cracking is aided through propagation along subgrain boundaries.1-5 Therefore, lowering ? sufficiently to interfere with substructure formation would be expected to retard growth rate. On the other hand, it is a general rule that resistance to fatigue cracking increases as strength is raised. Accordingly, there might still have been some doubt that Y was the controlling variable, since strength would be increased as y was lowered by the aluminum additions. To help in dispelling that doubt, an experiment was made on a polycrystalline Cu-Ni alloy similar in strength to the Cu-A1 alloys but of higher ?; the crack-growth interval was found to be essentially that of pure copper.' Further support for this position on stacking-fault energy as it relates to crack growth is derived from work by Boettner and McEvily,6 in which the actual crack-growth rate was measured on samples previously notched so as to minimize the nucleation period. Unfortunately, it was necessary in isolating strength level to compare different alloy systems and grain sizes. Recognizing the complication, it was still concluded that growth may be retarded by a reduction in y, per se. A related study has also been made by Roberson and Grosskreutz.7 The zinc content of a brass was systematically changed to alter strength and stack-ing-fault energy, although not below the 15 ergs per sq cm at which pronounced change in growth interval was found in the earlier work. The results were limited to more or less conventional S-N diagrams so that nucleation and growth events could not be separated. No definite conclusions were drawn, but

Jan 1, 1967

By Howard Willey

Mining operations of the Charcas unit at present are limited to the Tiro General mine at Charcas, in the State of san Luis Potosi, Mexico. The Tiro General mine was first operated during the Spanish occupation of Mexico for rich silver ores in an oxidized zone along the outcrop of the principal vein. In depth the ore is a complex sulfide with widely varying proportions of sphalerite, argentiferous galena and chalcopyrite ; and until recent years, it was economically impossible to carry on mining otherwise than irregularly in sections of the veins richest in galena and chalcopyrite. The advent of selective flotation brought the orebody as a whole within the field of economic interest, and a flotation mill of 650 metric tons daily capacity was constructed in the year 1925. The mining of partly worked-out sections of the mine, as well as the very heavy ground in most of the stopes opened in virgin ore, presented an unusually difficult problem. This paper describes the so-called "filled top slice" stoping method finally adopted as the standard system. Physical and Geological Conditions The principal orebody of the mine is an oreshoot about 1400 ft ng in a fissure vein striking about east and west and with an average lip of 70" to the north. The footwall of the orebody is fairly cleancu and regular both longitudinally and vertically and generally shows a dell-marked post-mineral slip. The footwall rock varies from a fairly strong limestone to a broken, metamorphosed limestone which requires heavy timbering. In some sections it is an altered, crumbly porphyry, which swells badly and necessitates frequent renewal of drift and raise tirnber. The hanging wall is irregular and frequently an assay wall. The stopina width ranges from a few feet up to more than 90 ft.; it averages about 30 ft. For the most part the hanging-wall rock is a shattered and altered monzonite porphyry, nearly aways requiring heavy timbering. The orebody is greatly fractured by post-mineral movement, which usually followed the footwall and left it as a smooth surface frequently covered with a slippery clay gouge. Two well marked transverse faults

Jan 1, 1931

By J. R. Long, E. T. Hayes, R. S. Dean, F. S. Wartman

THE production of titanium in 15-1b. lots and with a purity sufficient to be consolidated into ductile metal, as described in a previous paper,1 has provided adequate material for a study of the : physical properties of titanium and a more thorough examination of its working qualities. Data on the physical properties reported in that paper were obtained on metal fabricated by a fixed procedure, standardized for the purpose of control of the reduction, and are representative only of material fabricated under those conditions. There are many possible variables in the working schedule, which will have significant effects on the properties of the finished material; and since the previous working methods were not necessarily the best, an investigation of the fabrication of titanium by other methods was undertaken. In this work the consolidation of the powder by pressing and sintering was conducted essentially as outlined in the report cited' and all efforts were centered on fabrication methods for those powders and the properties produced by them. Hardness, density, microstructure, and tensile properties were determined at various stages in the working and annealing; and resistivity measurements were made on a few bars and drawn wire. [ ] CONSOLIDATION OF THE POWDER The screen analysis of the available titanium powder is given in Table I. No attempt was made to alter the size distribution from that noted because this powder, although coarse by normal powder-metallurgy standards, produced acceptable compacts suitable for the present work. Because of their large specific surface, finer powders are more contaminated by oxygen and produce harder compacts, which are difficult to work. The powder as produced is soft, compresses in a normal fashion, and exhibits very little tendency to adhere to the die surfaces. Unlike aluminum and magnesium powders, it can be readily pressed without the use of die lubricants. When compacted at so tons per

Jan 1, 1946

By J. R. Long, R. S. Dean, F. S. Wartman, E. T. Hayes

The production of titanium in I5-lb. lots and with a purity sufficient to be consolidated into ductile metal, as described in a previous paper,' has provided adequate material for a study of the physical properties of titanium and a more thorough examination of its working qualities. Data on the physical properties reported in that paper were obtained on metal fabricated by a fixed procedure, standardized for the purpose of control of the reduction, and are representative only of material fabricated under those conditions. There are many possible variables in the working schedule, which will have significant effects on the properties of the finished material; and since the previous working methods were not necessarily the best, an investigation of the fabrication of titanium by other methods was undertaken. In this work the consolidation of the powder by pressing and sintering was conducted essentially as outlined in the report cited' and all efforts were centered on fabrication methods for those powders and the proper- ties produced by them. Hardness, density, microstructure, and tensile properties were determined at various stages in the working and annealing; and resistivity measurements were made on a few bars and drawn wire. Consolidation of the PowdeR The screen analysis of the available titanium powder is given in Table I. No attempt was made to alter the size distribution from that noted because this powder, although coarse by normal powder-metallurgy standards, produced acceptable compacts suitable for the present work. Because of their large specific surface, finer powders are more contaminated by oxygen and produce harder compacts, which are difficult to work. The powder as produced is soft, compresses in a normal fashion, and exhibits very little tendency to adhere to the die surfaces. Unlike aluminum and magnesium powders, it can be readily pressed without the use of die lubricants. When compacted at 50 tons per

Jan 1, 1946

By J. R. Long, E. T. Hayes, R. S. Dean, F. S. Wartman

The production of titanium in I5-lb. lots and with a purity sufficient to be consolidated into ductile metal, as described in a previous paper,' has provided adequate material for a study of the physical properties of titanium and a more thorough examination of its working qualities. Data on the physical properties reported in that paper were obtained on metal fabricated by a fixed procedure, standardized for the purpose of control of the reduction, and are representative only of material fabricated under those conditions. There are many possible variables in the working schedule, which will have significant effects on the properties of the finished material; and since the previous working methods were not necessarily the best, an investigation of the fabrication of titanium by other methods was undertaken. In this work the consolidation of the powder by pressing and sintering was conducted essentially as outlined in the report cited' and all efforts were centered on fabrication methods for those powders and the proper- ties produced by them. Hardness, density, microstructure, and tensile properties were determined at various stages in the working and annealing; and resistivity measurements were made on a few bars and drawn wire. Consolidation of the PowdeR The screen analysis of the available titanium powder is given in Table I. No attempt was made to alter the size distribution from that noted because this powder, although coarse by normal powder-metallurgy standards, produced acceptable compacts suitable for the present work. Because of their large specific surface, finer powders are more contaminated by oxygen and produce harder compacts, which are difficult to work. The powder as produced is soft, compresses in a normal fashion, and exhibits very little tendency to adhere to the die surfaces. Unlike aluminum and magnesium powders, it can be readily pressed without the use of die lubricants. When compacted at 50 tons per

Jan 1, 1946

By R. G. Hall

WHEN we want to interpret some problem which faces us at the present, if that problem be a social or political movement, we turn to the pages of history for 'information. If the problem be one of science or of industry we turn to the library of the subject and endeavor to translate the present from the experience of the past. I wonder if you would bear with me for a few minutes as I look back to the time when I was going through mining school and looking forward with hope, it is true and with confidence also, but still with some trepidation and an occasional qualm, to the month of June when the class of 1897 would be hunting jobs. Those were the years 1893 to 1897. Those years saw the Treasury of the United States so empty of gold that the President had to appeal to financiers to accept the country's promises to pay in return for $100,000,000 in gold. And the invectives that were hurled at both their heads for such a betrayal of the people sound strangely similar to those you read today being daily written and screamed at another President for taking us into the League of Nations or for not issuing bonds in huge amounts for unemployment relief, or for not adopting somebody else's particular specific for the relief of hard times.

Jan 1, 1931

By Charles S. Barrett

There is a road into the microscopic realm that has remained untraveled through all these years of intense activity with high-power optical and electron microscopy. The road is worthy of careful scouting by metallurgists and other investigators, for it leads into relatively new country and it makes some areas accessible that heretofore could be reached only by very indirect paths or by the use of imagination. And when the road passes through familiar territory it frequently permits a new view of commonplace things that should prove of value from time to time. An accepted way to interest people in new sights such as this is to present an illustrated travelogue. This I propose to do, using many pictures taken in my recent exploration of this road. In the manner of travelogues, I shall touch briefly upon a large number of different subjects in physical metallurgy and shall attempt to give an exhaustive treatment of none, for the objective is to provide a means for further research, to interest others in it, and to indicate what appears at the moment to be profitable directions for it to take. The method I shall present involves X-rays, but does not make use of the usual accompaniments of X-ray research such as reciprocal lattices, Fourier series, or the stereographic projection. The method is so simple in its fundamentals that it could have been developed 2o years ago, or perhaps even 30 years ago. It is well to have a destination for our travels, so that when we are through we shall have explored some region of importance, despite our preoccupation with the novel means of transportation and our interest in the sights to be seen along the way. So let us name the Cold-worked State as our destination, and make side trips into the territories known as Recovery, Recrystallization, and Precipitation-hardening. A great many investigations have been made of the nature of cold-worked metal, and a great variety of methods used, many of which are indirect, such as X-ray line intensities, X-ray line widths, calori-metric measurements, and magnetic measurements. Since comprehensive reviews of these investigations have been published in recent years, they need not be discussed here. The investigations that were the direct forerunners of the present work should be first mentioned. In 1931 I became interested in the structure of individual spots in X-ray diffraction patterns.l When a crystal is placed in the narrow pencil of X-rays in a Laue camera, the spots recorded on the film are not always uniformly black, but may have an internal structure. The meaning of this may be understood from Fig. I, which represents a narrow beam containing X-rays of many wave lengths (''general radiation") penetrating a crystal in the direction of the arrow and forming a pattern on the vertical film at the right.

Jan 1, 1945

By P. E. Busby, C. Wells, M. E. Warga

Fundamental data on the rate of diffusion of boron in austenite and solubility of boron in the a and y phases of iron and steel have been obtained from deboronizing experiments and provide partial explanations for some of the phenomena observed in boron steels. The rate of diffusion of boron is about the same as carbon in austenite. The solubility of boron in austenite at normal heat-treating temperatures is less than 0.001 pct. A partial tentative Fe-B phase diagram in the important low boron concentration ranges and an equation representing the diffusion of boron in austenite are presented. A LTHOUGH a search of the literature revealed ALTHOUGHthat boron diffusion had not been studied quantitatively and systematically prior to 1948, a few qualitative observations which were made by following the diffusion of boron into iron packed in ferro-boron1-3 suggest that boron obeys normal diffusion laws and that the rate of diffusion increases with increasing temperature. The claim of Cornelius and Bollenrath1 that boron does not appear to influence the rate of carbon diffusion has recently been substantiated by Wells, Batz, and Mehl.4 Calculations based on data from the paper by Campbell and Fayv indicated that the diffusion coefficient (D) for boron in iron at 900°C is approximately 3x10 sq cm per sec; a value of 2x10-7 sq cm per sec at 1038°C has been reported by Digges et al in connection with decarburizing experiments on a commercial boron steel containing 0.43 pct C. During the period 1948 to 1950 several diffusivity constant (D) values for the diffusion of boron in the y phase of iron and steel and a number of solubility values for boron in both a and y phases were reported. It was concluded tentatively as a result of Metals Research Laboratory studies that D values for boron in y and a phases are about the same as for carbon in the comparable phasesa and that carbon up to 0.4 pct did not affect the rate of diffusion of boron in y iron above 1000°C within the limits of experimental error. Whether saturation of the y or a phases with carbon would significantly affect rates of diffusion of boron through them was then and still remains in doubt. The best estimate of Q (activation energy) was reported to be about 25,000 cal, somewhat lower than that for carbon in y iron. The solubility of boron in y iron at 1000°C was thought to be higher than 0.004 pct B but not as high as a more recent analysis of available data shows it to be. The solubility of boron in a iron at 700°C was reported to be 0.0004 pct B, but it would not have surprised the authors if the true solubility value is actually lower than this. Breaks in diffusion curves which were not understood when first obtained prior to 1950 have now been recognized as indicating solubility limits, and these are included in the present paper. Experimental Procedure Two methods were employed in an effort to determine diffusion coefficients (D) for boron in austenite. Early experiments involved the use of welded couples prepared in accordance with the procedure of Wells and Mehl,' but when the results of these experiments proved to be unsatisfactory for calculating D values, studies were continued by means of deboronizing experiments. In both cases, boron analyses following the diffusion anneal were carried out spectrographically and all D values were computed using the Grube solution of Fick's law. The precision of the spectrographic method used proved to be about equal to that reported by Corliss and Scribner" —average deviation from the mean about 5 pct of the amount present when the boron content is 0.003 pct. Concentration-penetration curves obtained from spectrographic analyses of welded couples generally indicated that practically no boron was transported across the weld interface during the diffusion anneal. Furthermore the concentration-penetration

Jan 1, 1954

By James Terry Duce

In order to facilitate interpretation of the data in this chapter, we print the following excerpts from the Circular to Authors. The field is the unit in this tabulation. In cases of fields extending across State boundaries, such as Rodessa, it is suggested that each State author treat the section of the field in his State as a unit, and by a footnote indicate that the field extends into an adjacent State. Each space in Table 1 may represent one of four possibilities; either it is not applicable to the particular field, or the proper entry is not determinable, or the proper entry may be determinable but is not determinable from data available to the author, or the proper entry is determinable. When spaces are not applicable, leave blank; in spaces where the proper entries are determinable from data available to the author, please insert y; in spaces where the proper entries are determinable by the author, make such entries. y implies a hope that in some future year a definite figure will be available. The entry of an 0 is a positive declaration, and an important declaration where it is in order. Inability to determine precisely the correct entry for a particular space should not lead the author to insert merely y. Contributions of great value may be made by the author in many cases where entries are not subject to precise determination. In such cases the author should use his good judgment and make the best entry possible under the circumstances. For many spaces the correct entries represent the opinion of the author (for example, "Area Proved") and in such cases the entry need not be hedged to such extent as when the quantities are definite yet can be ascertained only approximately by the author. In cases under definite headings but where figures are only approximate, the author may use x. It is thought that the nearest whole numbers are sufficiently accurate for our purposes except as to percentage of sulphur in oil. If an author desires to report any other figures to tenths, he may do so. The quantity of gas produced should include, where possible, gas sold or otherwise marketed, and gas blown into the air, burned as flares or otherwise wasted. Segregation of these figures would be interesting if the authors can make such segregation. In any event, the figures should represent as nearly as possible the total quantity of gas removed from the reservoir. Under the columns on "Depth," the average depth to the top of the productive zones and to the bottom of the productive wells, when subtracted, should give the approximate thickness of the productive zone. For fields where this is not true

Jan 1, 1940

By Frank T. Sisco

SHORTAGES of metals and minerals and substitution of less critical materials for those in which a virtual famine exists received detailed and frank discussion at a recent conference in Washington called by Robert E. McConnell, director of the Conservation Section, Office of Production Management. Representatives of the large engineering societies in the United States and O.P.M. department heads participated in the discussion. To open the session Mr. McConnell called upon Zay Jeffries, chairman of the O.P.M. Advisory Committee on Metal Conservation and Substitution, to summarize the present situation. Dr. Jeffries touched briefly on the status of metal shortages, which has already received considerable attention in the popular press, and said that much of the present difficulty was caused by the too-hasty substitution-without sufficient con¬sideration of the immediate conse¬quences-of metals having ordinarily a small yearly consumption, for those having a much larger annual consumption. As a result, all the alloying metals used in alloy-steel manufacture have become scarce, with the exception of molybdenum; further¬more, despite a reserve of 11,000 tons of molybdenum in this country and despite a normal consumption of only about 3500 tons and a prospective annual production rate of 21,000 tons by October, a shortage of molybdenum is possible before this war is over.

Jan 1, 1941

By Richard W. Lodge

Mr. H. R. Batcheller, of the class of 1894, Massachusetts Institute of Technology, while experimenting with chlorine gas on a certain lot of roasted concentrates, met with the following difficulties: 1. A poor extraction of the gold. 2. A very large consumption of chlorine gas. 3. Inability to precipitate all of the gold from the solutioil containing the AuC1,. 4. The bullion obtained was very base. These difficulties were the same whether the chlorine was generated from H2SO47 MnO29 and salt, or whether H2SO, and bleaching powder were used. They may be accounted for partly by the presence of some arsenic left in the roasted ore, and partly by the presence of copper in the solution containing the AuCI3. It was therefore suggested to try the effect of bromine on a similar lot of ore. The use of this element is, of course, nothing new, but in the following experiments it seemed to present many advantages over chlorine. The material worked upon consisted of some concentrates containing 2.31 ounces of gold per ton, and 34.26 per cent. of arsenic, which would correspoild to about 74.4 per cent. Of

Jan 1, 1896

By Leslie C. Richards

The competitive position of producers of industrial minerals depends upon the delivered price of their product. Freight charges are a major factor in the sales to consumers. A comparison of freight rates on movements of limestone and silica rock in the Pacific Northwest shows a wide variance in mills per ton mile for like hauls, thereby favoring some localities over others. Introduction: Sooner or later the potential miner of industrial minerals reaches the conclusion that of the various factors he must consider, the marketing of his product is. the most important. The sooner he realizes this the better, as successful industrial mineral producers .will confirm. Herein lies a difference between i.ndustria1 mineral mining and metal mining. Often in the latter, technical problems of mining or concentrating are equal to or even surpass those of marketing. This is not meant to imply that there are no problems in mining and beneficiation of industrial minerals, but these usually are outweighed by the problem of marketing. Recentlv. an official of a nationally known corporation :i the elecl.ro-metallurgical industry made an industrial mineral survey in the Pacific Northwest. In the course of his investigation he interviewed producers and potential producers of the various industrial minerals scheduled for use in the plant now being constructed in this area. He stated that he was interested in only three factors: namely, (1) Can your product meet our specifications? (2) Are you able to supply our tonnage requirements? and (3) What will be the delivered price? If there are several sources of supply of sufficient grade and tonnage, as is often the case in the Northwest, then the third factor becomes the important and deciding one. While industrial minerals are usually sold f.0.b. cars with the freight being paid by the buyer, it is the delivered and riot the f.0.b. price that determines the competitive position of the producer and his industrial mineral product. Unfortunately for both the consumers and producers of industrial minerals in the Northwest, the sources are generally a considerable distance from the markets. This necessitates long rail hauls, for which transportation charges make up the largest share of the delivered cost and the delivered price of the product. Is it any wonder then, that rail rates play such an important part in the marketing of industrial minerals? In order to sell his product, the producer must be able to deliver to the market at a competitive price. It must be remembered that his largest cost factor is rail transportation, and that he is limited to markets that he can reach competitively. Since the cost of rail transportation is so important, let us compare various freight rates in the Northwest and attempt to determine their influence on marketing. A study of all rates on all industrial minerals transported in this area, is beyond the scope of this paper. For the purposes of comparison, let us consider limestone (broken, crushed, or ground), and silica rock. These are widely used industrial minerals, and are carried by several different rail routes from.the sources of supply to the centers of consumption in the Pacific Northwest. Markets and Sources of Supply: Limestone has a number of uses in western Oregon and Washington. Among them are agricultural lime for the soils of the Willamette Valley and southwestern Washington; paper rock for the mills in such cities as West Linn, Oregon City, Newberg, St. Helens, and Salem, Oregon, and Camas and Everett, Wash.; chemical and metallurgical-grade limestone for the metallurgical plants centering around Portland, and the Tacoma-Seattle areas'; and sugar rock for the sugar refineries at Toppenish, Wash., and Nyssa, Oregon. Since limestone for cement manufacture is generally processed near the quarry, transportation

Jan 1, 1951