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By Ronald Gibala

THE Au-Ni alloy system is one of many binary systems in which the supersaturated solid solutions may exhibit a multistaged precipitation behavior during aging. In addition to the equilibrium phase separation, which was studied extensively years ago in the range 400" to 600",' there exists at least one earlier stage of precipitation, i.e., preprecipitation, which occurs below 300°C in quenched alls.-This note reports on some effects of composition on the preprecipitation in Au-Ni alloys as determined from resistivity measurements. The kinetics of the preprecipitation were studied in alloys of 15 to 85 at. pct Ni which were water- were found in alloys which after various quenching-and-aging treatments were slowly heated and cooled (1Z"C per hr) between room temperature and about 300°C. Two such heating-cooling curves for a 40 pct Ni alloy are shown in Fig. 2. Similar effects were observed in other 15 to 50 pct Ni alloys. These curves are characterized upon heating by two changes in slope indicated by A and B in the figure and upon cooling by a resistivity hysteresis of approximately the size of the original decrease in resistivity after the aging treatment. The inflection at B generally falls at about the same temperature for all heating curves for a given alloy and appears to be a critical temperature (T,) for the preprecipitation for that alloy. The values of T, for most of the 15 to 50 pct Ni alloys fall in the range 200" to 220°C. The position of the inflection at A depends upon the heat treatment prior to the heating-cooling run and perhaps the heating rate, which was held constant in these runs. The preprecipitates grown in by the appropriate aging treatments seem to decrease in size as the alloys are heated from A to T,, dissolve at T,, and do not reappear after cooling below T,. When similar heating-cooling treatments were performed on 60 to 85 pct Ni alloys, an entirely different behavior was observed. Typical results are shown in Fig. 3 for an 85 pct Ni alloy. In these

Jan 1, 1964

By Colman Goldberg

IT is customary to plot crystallographic planes or axes on a Wulff stereographic net which is ruled with parallels of latitude and meridians of longitude. If a single crystal is placed at the center of a sphere, the coordinates of a crystallographic plane or axis are the coordinates of the point where the axis intersects the sphere. The standard (HKL) projection is the projection for which the sphere is rotated so that the (HKL) pole is at the center of the projection. Schiebold and Sachs' and many others have published standard projections for the more important planes of a cubic crystal. With Tables I and 11, it is possible to plot any plane (HKL) of a cubic crystal on a standard (001) projection if the absolute values of the individual H, K, and L are nine or less, which is almost always the case. Using the methods outlined by Barrett,' the standard (001) projection can be rotated so that any arbitrary plane is at the center of the projection. The tables are believed to be important for two reasons: 1—The heretofore published standard projections usually are not of the proper size to fit the stereographic nets available. With these tables a standard projection can be made which will be of exactly the proper size for the available stereographic net. 2—With the tables, planes that do not appear on the previously published standard projections can be easily plotted. For these reasons, the tables are especially useful in the study of optical reflections from etched surfaces and can also be used to make a standard projection for the axis which is normal to the macroscopic surface. (This axis can be found by X-ray or optical methods.) Then if the crystal is etched, the effect of the etchant can readily be determined by comparing the latitude and longitude of the reflecting planes (as determined with an optical goniometer) with the standard projection that has been prepared. Use of the Tables Fig. 1 shows the meridians and parallel which have been designated as zero longitude and latitude. The tables themselves are self-explanatory. The

Jan 1, 1953

By Bruce A. Kennedy

In recent months, public hearings held by the Senate Subcommittee on Minerals, Materials and Fuels on the Stillwater copper-nickel complex in Montana have been reviewed at great length in the press. Although the meetings were well managed by the Subcommittee and questioning was kept in line with the aim of the hearings-namely, how can re- sources be developed in a manner compatible with the preservation of the environment-it was alarming to read the apparently uninformed and questionable arguments presented by some witnesses who were attempting to prohibit mining in the area altogether. One spokesman even went so far as to urge that mining of the area be rejected be- cause, even if the mining operation did not pollute the areas, the effluent and waste produced by the people themselves could constitute a hazard to the environment and to themselves. This, of course, would be true to a point. However, if this or similar types of reasoning were used to reject mining of a large number of orebodies in the future, how is the United States going to meet its future mineral demands and what effect could this have on the economic strength of the country? Fall of the Roman Empire An interesting article in a recent issue of Time magazine came up with a new theory to explain the fall of the Roman Empire. Claire Patterson of CalTec, during a recent study of air pollution, investigated the historical worldwide distribution of lead. As lead was a by-product obtained from silver mining during historical times, he turned his attention to studying the production of silver during those eras. He discovered a very interesting fact-that, I unless the stock of metal is continually being replenished from the mines, accidental loss diminishes a country's stockpile of silver at a rapid rate, as much as 2 per cent per year. Patterson, a geochemist, theorized that with an accidental loss rate of 2 per cent per year, if the country's silver supply dried up, the entire existing stockpile could disappear in about a century.

Jan 1, 1971

Iron Ores and Blast Furnace Practice Concentration of Iron Ores in the United States. By T. R. Counselman. (Metals Technolog), December 1943) Selection of Blast-furnace Refractories. By Hobart M. KrANer and E. B. Snyder. (Metals Technology, April 1944) The Washing of Pittsburgh Coking Coals and Results Obtained on Blast Furnaces. By C. 1). King. (Metals Technology, September 1943) Steelmaking The Role of Basic Slags in the Elimination of Phosphorus from Steel. By Richard L. BArrett and William J. McCaughey. (Metals Technology, April 1944) The Relative Deoxidizing Power of Boron In Liquid Steel and the Elimination of Boron in the Open-hearth Process. By B. W. Gurry. (Metals 'Technology, December 1943) Manufacture and Properties of Killed Bessemer Steel. By C. C. Wright. (Metals Technology, June 1944) Hardenability Effect of Sixteen Alloying Elements on Hardenability of Steel. By Irvin R. Kramer, Robert Hafner and Stewart L. Toleman. (Metals Technology, September 1943) Effect of Quenching Temperature on the Results of the End-quench Hardenability Test. By Clarence E. Jackson and Arthur L. Chrjstenson. (Metals Technology, December 1943) Effect of Some Elements on Hardenability. By Walter Crafts and John L. Lamont. (Metals Technology, January 1944) Effect of Several Variables on the Hardenability of High-carbon Steels. By I?. S. Rowland, J. Welchner and R. IS. Marshall. (Metals Technology, January 1944) Mechanical Properties Influence of Hydrogen on Mechanical Properties of Some Low-carbon Manganese-iron Alloys and on Hadfield Manganese Steel. By Herbert H. Uhlig. (Metals Technology, June 1944) Aging and the Yield Point in Steel. By J. R. LOW, Jr., and 14. Gensamer. (Metals Technology, December 1943) Tensile Properties of Medium-carbon Low-alloy Cast Steels. By H. A. Schwartz and W. Kenneth Bock. (Metals Technology, August 1944) Variables Affecting the Results of Notched-bar 1mpct Tests on Steels. By CLarence 15. Jackson, MYRon A. Pugancz and Frank S. McKenna. (Metals Technology, August 1944) The Notched-bar Lmpact Test. By John H. Hollomon. (Meta1s Technology, April 1944) Hardness Measurement as a Rapid Means for Determining Carbon Content of Carhon and Low- alloy Steels. By K. L. Clark and NIcHols Kowall. (Metals Technology, January 1944)

Jan 1, 1944

By C. F. Cockrell, K. K. Humphreys, H. E. Shajer

It is quite conceivable that the question of using coal or an alternate fuel in the future by large industrial consumers may be decided on the basis of possible profitable utilization of flyash. Accordingly, the Coal Research Bureau at West Virginia University has been attempting to develop new uses for this waste material. This effort has resulted in the development of a process for producing flyash-based face brick and other structural materials which generally exceed published specifications for competitive clay-based materials. These structural materials, containing up to 97% waste coal ash, can be produced from flyash derived from most coals without regard to the physical or chemical properties of the coal ash. Preliminary production cost estimates indicate that face brick can be manufactured at a rate of 9000 brick per hr or more with a resultant gross profit of over $24.00 per thousand brick. Plant payout time for a plant of this size would be only about 1.2 years assuming a market price of approximately $55.00 per thousand, a well established figure for comparable clay brick. With flyash production expected to more than double in the next 15 years, there is an increasing need for a practical and Profitable method for the utilization of large tonnages of this material (see Table I listing total flyash production of utilities in each state of the U.S.). Present industrial and governmental physical and chemical restrictions, particularly for use as a lightweight filler or pozzolanic material, have limited the use of flyash considerably. For those ashes which have met the required standards, utilization is not always assured because of lack of promotion and poor public acceptance. Less than 6% of the total flyash production in the U.S. was sold in 1962. The remainder was dumped in disposal areas at costs as high as $2.42 per ton.' It is quite conceivable that in the near future the question of using coal or an alternate fuel by large industrial consumers may be decided on the basis of the possible utilization of flyash. To help insure future coal demands, the Coal Research Bureau at

Jan 1, 1968

By S. R. Elliott

THE principles of the caving system, as they apply to mining of soft iron-ore deposits, are well known, as this method has been in use for many years. It is, however, necessary to give a general description of it before describing the Athens method. The shaft and surface equipment should be placed at a sufficient distance from the orebody, so that the caving and pulling of the surface will not disturb the operations of the mine. Levels are started at the proper intervals, and when raises are completed, slicing commences at the top of the orebody and progresses downward. The necessary precautions are taken to avoid the occurrence of large open rooms and it is customary to break sufficient capping to form a mat to prevent heavy falls of ground from crushing through to the lower sublevels and endangering the lives of the workmen. Slicing is continued, and when sufficient width and length are undercut, the capping commences to cave, and in time a settlement occurs at the surface. As soon as this caving commences, the pressure on the timber naturally increases; after it extends to the surface, the amount of pressure has a certain relation to the depth. In other words, the pressure increases with the depth, but not in direct proportion. At great depths, such as that found at the Athens, 2500 ft. (760 m.), the pressure might be so excessive that the cost of keeping working places open would be prohibitive. The actual caving of the surface in a deep mine, with a great thickness of capping, is slow and often takes years to accomplish. After sufficient width and depth -have been undercut, the capping starts to break away, but through arching large masses of rock-.fill the opening, support the capping, and retard the continuation of caving. Caving to the surface is, therefore, retarded until either a sufficient thickness of the orebody is removed, or the width and length of the undercut part have been greatly increased. I wish to emphasize this fact of slow caving, for it is on, this principle that the success of the Athens system. largely depends.

Jan 8, 1920

By Rossiter W. Raymond

In the course of this address, President Raymond referred to the law, said to have been discovered at the French works of Terrenoire, that the amount of phosphorus may be increased without injury to steel, if the amount of carbon be proportionately decreased. The works named have been for more than a year, it is said, manufacturing in the open hearth, by the Martin process, steel rails containing as high as 0.35 per cent. of phosphorus, with about 0.15 per cent. of carbon, which were not found inferior to Bessemer rails. It is not claimed by the manager of the works that phosphorus is an ingredient to be preferred, or purposely introduced; but only that materials containing it (such as old iron rails, etc.), can be succesfully employed. Other parties have apparently a higher opinion still of the new manipulation, and are prepared to claim for " phosphorus steel" superior qualities. Mr. I. Lowthian Bell alluded to the subject in his recent address as President of the British Iron and Steel Institute, but without expressing a positive opinion. After pointing out that the commercial value of the process turned on the cheap manufacture of ferro-manganese, by means of which only could the necessary amount of manganese be introduced into the Martin bath, without increasing its contents of carbon, Mr. Raymond proceeded to say that the principle alleged to have been discovered at Terrenoire was already known years ago, in this country, at least. Not only had steel been manufactured here, containing high percentages of phosphorus, coupled with low percentages of carbon, and suitable for use in rails, boiler-plates, etc., but the reason of its surprising qualities had been distinctly surmised, if not widely proclaimed. The following analyses and extracts from private letters prove these assertions. Some of them assert a similar principle in .the case of wrought iron; but the analyses, and the remarks based upon them, have reference solely to the steel manufactured under the superintendence of Mr. Slade, at the works of the New Jersey Steel and Iron Company in Trenton.

By Rossiter W. Ph. D. Raymond

(From the President's Address at St. Louis, 1874.) IN the course of this address, President Raymond referred to the law, said to have been discovered at the French works of Terrenoire, that the amount of phosphorus may be increased without injury to steel, if the amount of carbon be proportionately decreased. The works named have been for more than a year, it is said, manufacturing in the open hearth, by the Martin process, steel rails containing as high as 0.35 per cent. of phosphorus, with about 0.15 per cent. of carbon, which were not found inferior to Bessemer rails. It is not claimed by the manager of the works that phosphorus is an ingredient to be preferred, or purposely introduced; but only that materials containing it (such as old iron rails, etc.), can be succesfully employed. Other parties have apparently a higher opinion still of the new manipulation, and are prepared to claim for "phosphorus steel" superior qualities. Mr. I. Lowthian Bell alluded to the subject in his recent address as President of the British Iron and Steel Institute, but without expressing a positive opinion. After pointing out that the commercial value of the process turned on the cheap manufacture of ferro-manganese, by means of which only could the necessary amount of manganese be introduced into the Martin bath, without increasing its contents of carbon, Mr. Raymond proceeded to say that the principle alleged to have been discovered at Terrenoire was already known years ago, in this country, at least. Not only had steel been manufactured here, containing high percentages of phosphorus, coupled with low percentages of carbon, and suitable for use in rails, boiler-plates, etc., but the reason of its surprising qualities had been distinctly surmised, if not widely proclaimed. The following analyses and extracts from private letters prove these assertions. Some of them assert a similar principle in -the case of wrought iron ; but the analyses, and the remarks based upon them, have reference solely to the steel manufactured under the superintendence of Mr. Slade, at the works of the New Jersey Steel and Iron Company in Trenton.

Jan 1, 1875

By M. Gensamer

It has been suggested by a number of people that it would be worth while for some one to attempt to summarize or condense the proceedings of this symposium. This task has fallen to me as organizer and co-chairman. Its difficulty will be appreciated by anyone who attempts to read the whole proceedings. It is therefore with trepidation that I offer the following digest. In recent years there has been a renewal of interest in America on this subject of the cohesive strength of materials, and a growing appreciation of the need for a better theory of cohesion failure. The theories of elastic action and plastic action are well developed, particularly the former. The theory of plastic action is still in the course of development, but it is well along. Plastic action is terminated by cohesion failure and what is needed is a theory that will tell us when to expect the cohesion failure. In the past it has generally been assumed that cohesion failure will occur when a critical value of the maximum tensile stress has been reached. Many experiments have shown that this is not strictly true, and this symposium concerns itself with the failures of this simple hypothesis, and with the efforts that have been made to devise a more satisfactory theory. The most active contributor in recent years to knowledge in this field is Dr. McAdam, and he was asked to open the symposium with a summary or condensation of his papers and views. Undoubtedly it is presumptuous to attempt a still greater condensation, but perhaps it will be useful, because even his contribution to this symposium contains no summary, no concise statement of just what his contribution has been. Dr. McAdam makes two main points The first is that the cohesive strength is not a single valued quantity, but that it is a function of all three principal stresses and hence must be represented diagrammati-cally by a surface in a three-dimensional figure, Dr. McAdam has attempted so to delineate the cohesion limit, basing his

Jan 1, 1945

By J. W. Eckerd

Anthracite mining developments have not been as spectacular as the advances made for bituminous coal. The reasons are well known, i.e., steeply pitching seams of the western, eastern, middle and southern fields, and the physical conditions of the strata in which the seams are situated. Beds with moderate pitches (30º to 35º or less) have been mined with coal planers, longwall with movable props, shaker chutes, coal borers and large diameter boring machines. However, the use of this equipment has been limited to a relatively small portion of the production. Long-hole drilling has been developed from a point where holes of 25 or 30 ft have been replaced by those up to 130 ft. This has been possible through the introduction of primacord and similar detonating agents that can fire a long train of explosives with one cap. The usual practice in long-hole mining is to drive a gangway, chutes and monkey heading, or return airway, in the normal development manner. Two breasts can then be driven from the lower to the upper level to act as openings for the beginning of the long-hole work. Following completion of the development, holes can then be drilled from the monkey headings 100 ft or more up the pitch through the coal to within 15 ft or more of the upper level, depending on the nature of the coal on the roof. The thickness of the coal bed determines the spacing of the long holes, although they usually are on 6-ft centers for a 6-ft thick coal seam. The Bureau of Mines has conducted extensive investigations and tests on the development of a hydraulic mining system to be used in conjunction with hydraulic hoisting. Tests were conducted in cooperation with a large anthracite producer in a coal seam from 10 ft 6 in. to 15 ft in thickness and on a pitch from 0º to 20. This particular mining procedure is adaptable only to thick seams on relatively flat pitch as the maneuverability of the hydraulic jumbo is an important restricting factor.

Jan 2, 1968

By G. F. Dillion, A. F. Armington

THE present method for the ultrapurification of boron involves the formation, distillation, and decomposition of boron tribromide.' However, the boron tribromide prepared contains several impurities in the ppm range, even after distillation. Some of these impurities, notably carbon, can be reduced after decomposition by zone refining. In this study, a comparison of the purity of boron tribromide at various formation temperatures is presented. The apparatus employed consisted of a bromine flask connected to a 22 mm ID horizontal quartz reaction tube packed with amorphous boron powder, which was in turn connected to a receiving flask cooled with an ice bath. Argon was used as a carrier gas. The approximate rate of passage of bromine to the reaction tube was 25 g per hr. The reaction was first investigated at several temperatures in order to determine the lowest temperature necessary to produce a colorless product which was assumed to be an indication of complete reaction of the bromine. The lowest temperature found in this study was 420oC. The amount of impurities found in the boron tribromide at various formation temperatures is shown in Table I. The data presented are emission spectroscopic results of boric oxide produced by the hydrolysis of 2 to 3 g of boron tribromide in 10 ml of distilled water. After hydrolysis, the samples were dried several hours on a hot plate. Assuming equilibrium conditions in the reactor, one can make approximate thermodynamic calculations estimatling the completeness of reaction of bromine with boron and its impurities at various temperatures. Data for these calculations were taken from Rossini,3 and must be taken as approximations since the T?S factor was not included in the calculations. The results of such calculations indicate that, with the exception of carbon bromina-tion, all impurities would react almost to completeness (> 99 pet) at all temperatures between 400" and 900oC. In the case of carbon, which cannot be accurately analyzed spectroscopically, it is estimated that only about one sixth as much carbon tetrabromide would be formed at 400" than at 900°C. Since some marked reductions in impurity content were observed at the lower reaction temperature which would not be predicted by thermo-

Jan 1, 1962

By H. W. Kerr, B. Soutiere

THE possibility of using unidirectionally solidified eutectic alloys as high-strength composite materials has been investigated by several workers. Unidirectionally solidified lamellar and fibrous eutectics have been shown to have good short-time structural stability at temperatures close to the eutectic melting temperature.'-4 Several investigations of both short-time high temperature tensile properties and creep properties of eutectic alloys have been carried out,3-" with promising results. Little work has been reported, however, on the thermal stability of eutectic alloys which have been unidirectionally solidified and subsequently deformed in compression. Since processes such as rolling and grinding introduce compressive stresses, and since the properties depend on the spacing and perfection of the composite structure10,11 this aspect is of definite importance if unidirectionally solidified eutectic alloys are to be considered for commercial use. A Cd-Zn alloy made from 99.999 pct starting materials was cast into a graphite boat and zone levelled12 to obtain a completely lamellar structure at one end of the bar. Sections from this region of the bar were removed, recast into 6.5 mm I.D. Pyrex tubing, and solidified unidirectionally upwards at a rate of 2.8 cm per hr. Specimens were cut from the solidified rods, heated in air at 200°C (0.88 of the eutectic melting temperature) for various lengths of time, and examined metal-lographically. Compression specimens were also cut from the solidified rod carefully machined to a length of & in., and deformed with the compressive axis parallel to the original growth axis to produce a total longitudinal strain of 12 pct. Some of these specimens were examined metallographically; others were heated in air at 200°C for various lengths of time and then examined. Metallographic examination of the deformed specimens showed the two types of deformation previously described; slip lines13 (smoothly bent lamellae) and kinks13,14 (sharply bent lamellae). Very close to the specimen ends there were a large number of deformation bands, but at a distance of about -re- in. the deformation was very localized, as shown in Fig. 1.

Jan 1, 1970

By R. P. Rothwell

THE milling of silver ores has arrived at a great degree of perfection in the mining districts of our Western States and Territories, and I have thought the record of the practical results obtained at the present time, in a few of the principal districts, would prove of value and interest to many of our members, both at home and abroad. An American silver mill is composed, in descending order from where the ore is dumped, of: 1st. A rock-breaker, usually of the Blake or Alden pattern ; 2d. The battery of stamps, the number of which varies from 5 to 120, generally in batteries of 5 or 10 heads, so arranged that a single battery may stand while the others are running; 3d. The tanks where the crushed ore settles (if it is a wet stamping-mill), or of a drying-floor if the crushing is done dry; 4th. Amalgamating pans ; 5th. Settling pans ; 6th. Agitators or pans in which mercury escaping in the tailings is caught; 7th. Blanket sluices, over which the tailings run, and where mercury and unamalgamated sulphides are saved. A reference to the engravings (see plate), which show one of the latest forms of an 80-stamp silver-mill run by a turbine water-wheel, will show clearly the arrangement of the several parts. THE ONTARIO, UTAH, SILVER MILL. One of the best examples of a silver-mill, and at the same time one of the most successful concerns in the West, is the mill of the Ontario Silver Mining Company, near Salt Lake, in Utah. This mill treats the ore from the Ontario mine, ore which at present is very base, being composed of zinc, lead, and silver sulphides and silver chloride in a quartz gangue. This ore has become baser as the mine attained greater depth, though the vein holds its own, or rather increases, both in thickness and richness. The mill is man¬aged in a skilful and economical manner, though the necessity for * Read at the Montreal meeting, September, 1879.

Jan 1, 1880

By O. Nomland

The work of The Bahrein Petroleum Company, Ltd., on Bahrein Island consisted mainly in continuing development work and prospecting previously reported. The exploratory work, however, has been greatly minimized and new wells are being drilled, chiefly for the development of larger production; 20 wells had been completed by the end of 1935 and 8 were being drilled. In addition to what has been referred to as the ''main pay," two deeper productive horizons have been discovered, which apparently will greatly increase the potential of the field although the areal extent of this lower production has not yet been determined. The proven acreage of the "main pay" is more than 12,500 acres. Current production (principally from the upper horizons) is about 13,400 bbl. a day. The construction of a 10,000-bb1.-a-day refinery has begun and is to be in operation by July, 1936. It is expected that the capacity will be considerably increased at a later date. The construction of office buildings and a permanent camp has been almost completed. In Saudi Arabia the California Arabian Standard Oil Co., a wholly owned subsidiary of the Standard Oil Company of California, spudded in a well in April, 1935, near the village of Dammam, on the Persian Gulf coast of A1 Hasa. Although several important showings of high-gravity oil and considerable gas have been found, the well is not yet considcred a commercial producer. Dammam well No. 2 has been started farther south on the same structure. A great deal of reconnaissance and some detailed geological work has been completed during the last three field seasons. In order to overcome difficulties of transportation over the desert sand, unusual methods have been used. The parlies penctrating the interior by the use of automobiles and trucks have been supplied with gasoline and provisions by caravans of camels. Mail and supp1ies of lighter weight urgently needed have been carried to the field men by an airplane operated by the geological division of the company. Each party has been supplied with a radio receiving and transmitting set to keep in contact with the airplane as well as with geological headquarters at Jubail on the coast of A1 Hasa.

Jan 1, 1936

By W. J. Locher

One important means of reducing steel consumption in grinding mills is not mentioned in S.G. Malghan's paper. It is simply to reduce the oxygen content in the mill and pulp. While oxygen dissolved in pulp is not readily reduced without additives, reduced aeration and reduced ventilation of grinding mills are often feasible. It is not necessary to completely eliminate the oxygen to achieve substantial benefits, since corrosion rates vary with oxygen content in a manner analogous to combustion rates as oxygen content increases. It is difficult to generate indisputable quantitative data on the relationship of oxygen reduction in a milling system to changes in consumption of grinding steel. Perhaps this accounts for the absence of technical papers on the effects of reducing oxygen content in grinding mills by reducing aeration of pulp and ventilation of grinding mills. One qualitative observation is that mills operating at a lower percent of critical speed will tend to have lower media consumption for similar fineness of grind without necessarily having an equivalent reduction in power consumption per ton of product. Reduced mill speed would also tend to reduce both ventilation of the mill and entrainment of air in the pulp. Larger grinding mills tend to be more media efficient because they operate at a greater ratio of charge volume to pulp surface area, which will tend to reduce the aeration per unit of pulp volume. The mechanical steps required to reduce aeration of grinding mill pulps depend on the configuration of the grinding circuit and related process. Reply by S.G. Malghan Mr. Locher stated that my paper did not mention the reduction of oxygen content of the pulp as a potential method of decreasing the steel consumption. I would like to bring to the attention of Mr. Locher that an indirect reference was made to the fact that pulp oxidation potential controls the corrosion wear of steel. Though dissolved oxygen is one of the factors that controls oxidation potential, additional discussion was deliberately avoided for the reasons mentioned by Mr. Locher. The most important reason being the difficulty of decreasing and controlling the oxygen concentration of the pulp in a commercial mill.

Jan 1, 1984

By O. Nomland

The work of The Bahrein Petroleum Company, Ltd., on Bahrein Island consisted mainly in continuing development work and prospecting previously reported. The exploratory work, however, has been greatly minimized and new wells are being drilled, chiefly for the development of larger production; 20 wells had been completed by the end of 1935 and 8 were being drilled. In addition to what has been referred to as the ''main pay," two deeper productive horizons have been discovered, which apparently will greatly increase the potential of the field although the areal extent of this lower production has not yet been determined. The proven acreage of the "main pay" is more than 12,500 acres. Current production (principally from the upper horizons) is about 13,400 bbl. a day. The construction of a 10,000-bb1.-a-day refinery has begun and is to be in operation by July, 1936. It is expected that the capacity will be considerably increased at a later date. The construction of office buildings and a permanent camp has been almost completed. In Saudi Arabia the California Arabian Standard Oil Co., a wholly owned subsidiary of the Standard Oil Company of California, spudded in a well in April, 1935, near the village of Dammam, on the Persian Gulf coast of A1 Hasa. Although several important showings of high-gravity oil and considerable gas have been found, the well is not yet considcred a commercial producer. Dammam well No. 2 has been started farther south on the same structure. A great deal of reconnaissance and some detailed geological work has been completed during the last three field seasons. In order to overcome difficulties of transportation over the desert sand, unusual methods have been used. The parlies penctrating the interior by the use of automobiles and trucks have been supplied with gasoline and provisions by caravans of camels. Mail and supp1ies of lighter weight urgently needed have been carried to the field men by an airplane operated by the geological division of the company. Each party has been supplied with a radio receiving and transmitting set to keep in contact with the airplane as well as with geological headquarters at Jubail on the coast of A1 Hasa.

Jan 1, 1936

By A. R. Troiano, W. J. Barnett

The existence of a grain size stabilization effect on martensitic type reactions as shown by Scheill in an iron-29 pct nickel alloy and by Troiano and Tokich2 in cobalt prompted a review of other martensitic reactions to determine if this stabilization effect is characteristic of all martensite type reactions. Preliminary work has shown this effect to be present both in the gamma —+ epsilon transformation in an iron-20 pct manganese alloy and the martensite transformation of SAE 4140 and 3 pct Cr-O.40 pct steels. No appreciable effect was found in an SAE 2340 steel. The M, temperature for the gamma —+ epsilon transformation was lowered from 380°F to about room temperature by varying the annealing treatment following cold work as shown in Table I. The effect of austenitic grain size on the M, of three steels is shown in Table 2. M, was deter- mined by the conventional quench-temper method of Greninger and Troiano. In a single crystal the change in external shape concomitant with the homogeneous shear mechanism of the martensite transformation can take place unhindered. In a polycrystalline specimen a restraint of these changes must occur at the grain boundaries. Therefore, the smaller the grain size the greater the shear strain energy necessary for the formation of a martensite crystal. The degree of lowering of M, due to the reduction of grain size is much greater when the change in crystal structure involves only a small energy change, such as face-centered cubic —+ close packed hexagonal (that is, CO and Fe-20 pct manganese alloy). The maximum lowering of M, observed in the steels investigated was 50°F with a change in the ASTM austenitic grain size of 1-2 to 8-9. In comparison, the crystal structure change face-centered cubic —+ body-centered tetragonal involves a considerable energy change. There is little doubt that with much finer grain sizes the increased grain boundary restraint would greatly enhance this stabilization effect. The implications of this phenomenon are multifold. Undoubtedly. under certain conditions it offers a method of stabilizing high temperature phases for room temperature

Jan 1, 1949

By A. E. Schuetz, A. E. Roswell, W. R. Hibbard

THE drawn wire texture of body-centered cubic iron,' tungsten,' and molybdenum~ as been determined to be a [110] direction parallel to the wire axis. The purpose of this study is to extend the available information on body-centered cubic wire textures to other metals and alloys. Wires were produced using hand wire rolls and dies as given in Table I. In addition, attempts were unsuccessful to draw wires from chromium, vanadium (Vanadium Corp. of America), and tungsten (Cleveland Tungsten Inc.). Although it is known that wires can be made from these materials, suitable techniques were not readily adaptable. Where necessary, wires were polished and etched to form flat ribbons 0.005 to 0.007 in. thick, and transmission X-ray patterns were taken using molybdenum radiation with the specimen tilted 0 degrees from the perpendicular toward the beam to critically cover the wire axis. Analyses were made of (110), (002), and (112) reflection circles. In all cases reflection maxima indicated the texture to be a single [1101 deformation fiber, as illustrated by Fig. 1 for molybdenum. In the case of the hot-worked ß brass, a second texture, [loo], was also found, but this is believed to be the result of recrystallization since it has been reported for re-crystallized molybdenum wires' and it was not present in the cold-drawn ß brass. The difference in drawability between the 51.92 pct Cu ß brass and the 62.5 pct Cu ß brass (containing some grain boundary a due to incomplete quenching) is quite striking, since the latter could be cold worked readily while the former had to be hot worked to avoid cracking. Summary The deformation texture of drawn body-centered cubic wires of ß brass, iron, molybdenum, niobium, and tantalum is essentially a single [110] fiber as predicted by theory.' Acknowledgment The authors wish to thank the suppliers of the metals listed in the text, and the Grant-in-Aid from the Research Fund of the Society of the Sigma Xi and Scientific Research Society of America which made possible the purchase of X-ray equipment.

Jan 1, 1952

THE second operation in the art of casting, and one of the greatest importance, is that of melting and thoroughly liquefying the materials of which you wish to make your casting. On this operation depends the whole outcome of your intentions and the perfection of your work. Without it, even though you had a great abundance of moulds and vast quantities of bronze, your desires, labor, and expense would all be in vain. In this operation I find on consideration that, in addition to experience, there are three necessities-perhaps indeed four-that must be provided without fail. The first is the furnace or other agent which contains the fire and the metal brought together. The second is the wood or charcoal which is the necessary and proper nutriment of the fire, from whose virtues are derived the greater or lesser forces which, according to their kind, are ready to effect what is required. The third is to have the materials disposed to easy fusion by means of corruption, alloying, or by their own nature. The fourth, as the motivating cause of the whole, could perhaps be listed as the first-this is the ingenuity and good judgment of the worker, together with the bodily exertions not only of himself but also of his helpers in addition. For, besides a certain ordinary caution, it is necessary to pay particular attention, first, to see that the furnaces, machines, ladles, hearths, refineries, and other kinds of instruments or similar vessels be made so as to dispose the metals for melting, and, when melted, that they easily maintain them so. These should also be prepared in such a way that they cannot be injured by the fire, for if they should be damaged the operation would fail. In order to do this, it is first necessary that you arrange the instruments with forethought and action so that the power of the fire can operate. Fire operates on things only when brought together with them in long-continued operation, or when driven by a great force of wind. It burns many things and softens others, but it makes the metals as liquid as water.

Jan 1, 1942

By Hon. Charles McCrea

MINING taxation is a subject which bears definitely upon-the welfare of the mining indus-try. Every government must have a revenue but that revenue should be raised in such a way as to hamper as little as possible legitimate enterprise or industry. A mining tax should be fair, and one which appeals to the natural sense of justice. Our present system is a tax on net- profits after all expenses are met. On profits in excess of $10,000 the Mining Tax Act takes three per cent., one-half of which goes to the Govern-ment and one-half to the municipality in which the mines are situated, to meet local needs for roads, schools, etc. On profits from one to five million dollars", the tax is five per cent.; over five million, six per cent., and so on. The first $10,000 profit is exempt. The result is that if a mine is worked at a loss, it pays no tax at all; if it makes a small profit, it pays a small tax; if profits are large, the tax increases accordingly. It is difficult to imagine a fairer or less onerous method of taxation, or one better adapted to meet fluctuating conditions from year to year as profits rise or fall. A just and fair tax should be levied on profits, never on capital. There is, one branch of the mining industry upon which is levied a higher tax than upon other branches, namely, the nickel industry. I see no good reason why any branch of the mining industry should be discrim-inated against on a profits tax basis. A mining tax should not discourage development. The present tax meets this requirement. In the early years of a mine, when it is all outgo and no income, the mine pays no tax. Not until it reaches a productive and. profitable stage does the tax take effect, and then the mine can afford to pay it. Further, a tax on profits does not operate against the opening up of low-grade deposits, or those in which the chance of success is to a certain extent speculative.

Jan 10, 1923