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By Robert Linton

In 1898, Joseph L. Giroux and J. A. Snedaker organized the Pilot Knob Copper Co. and began developing the Pilot Knob mine at Kim-berly, Nev., for high-grade copper ores, carrying good gold and silver values, that the formation had disclosed. At that time the nearest railroad was over 150 mi. distant. The high-grade ores did not prove to be extensive at this point—at least to the depth (240 ft.) to which the work was carried—but development of neighboring claims indicated extensive deposits of sulfide porphyry ore of concentrating grade lying at shallow depth, and deeper deposits of direct-smelting oxidized ores occurring in limestone near the limestone-porphyry contact. The properties passed through the hands of several organizations, with only meager development, until acquired in 1913 by Consolidated Coppermines Co., whose holdings now comprise 3480 acres of mining claims in the Robinson district. Since that time development has been prosecuted more actively; and for the purpose of determining the most efficient and economical method of treating the ores, considerable testing work has been done during the past three years, both in the laboratory and in actual mill operations. At first, the shipments were of ore high enough in grade to be profitable even with the long wagon hauls to the railroad and prevailing freight and smelting charges. In 1905, a blast furnace and a concentrator were erected at Kimberly. On account of insufficient ore supply, the blast furnace was never blown in and later was dismantled. The concentrator as originally equipped was operated for only about two months, both because the ore supply at that time was not sufficient and because gravity concentration did not yield satisfactory extraction. The location and arrangement of the mill further entailed high operating costs. In 1908, the Nevada Consolidated Copper Co. began to mill successfully, on a large scale, its sulfide porphyry ores, which are similar in character to the adjacent Coppermines ores. After that time, all of the ores and concentrates produced by Coppermines Company were smelted and a considerable part of the Coppermines low-grade ores concentrated at the Steptoe works of the Nevada Consolidated Co.

Jan 1, 1921

By H. A. Bedworth

ALLOYS of copper and silicon have been known for one hundred years or more but the commercial development of this type of alloy has taken place during the past few years. In 1905, Sperry1 proposed the use of copper-silicon alloys for springs and other purposes for which copper-tin bronzes were used. Some attention was given to this proposal at the time but no one succeeded in producing a practical alloy containing more than a fraction of a per cent. of silicon. The equilibrium relations of the copper-silicon system were studied first by Rudolfi2 and later by Sanfourche3 and Corson.4 The constitution of the system has also been recently investigated by Matuyama,5 and in the laboratories of the American Brass Co. by Smith.6 Some of the physical properties of the copper-silicon alloys have been investigated by Norbury7 and by Geiss and Van Liempt.8 Summarizing the results of various investigators of, the constitution of copper-silicon alloys, the solubility reaches its maximum value, 6.7 per cent. silicon, between 721° and 782° C. At 852° C. the solubility is 5.25 per cent., while at 400° C. it is only 4.1 percent. silicon. The copper-silicon alloy begins to get so hard at about 3 per cent. silicon that it is difficult to manage. It was found by Jacobs that the addition of manganese to this alloy considerably improved the working

Jan 1, 1929

THE problem of reaction rates in the open-hearth process is essentially that of trying to form a fairly clear picture of the "chemical mechanisms" in the bath. Quantitative data on reaction rates would not be very useful even if they were available; however, what few , approximate data there are, can be used in combination with data given in Chapters XVI and XVII to sketch a picture of the "chemical mechanics" of the open-hearth process that is consistent with essentially all the present available evidence. The result may later be found incorrect in many details but even so it will illustrate certain useful methods for obtaining a clearer understanding of the process. As discussed in the last portion of Chapter XIII chemical reactions in general involve the following factors: 1. The reacting molecules are mixed together in space in such fashion as to favor collisions among them. 2. A certain number of collisions occur per unit time among the reagent molecules, depending on their concentration and on temperature. 3. A certain percentage of these collisions result in reaction, these being the collisions between those molecules possessing at the moment energy levels above certain minimum values. The temperature factor enters mainly through (3), and its effect is very marked. (What is called temperature is really the mean energy content of all the molecules of the substance involved; at any one temperature a certain proportion of the molecules will have much higher energy content than the mean value.) Various reaction rates measured at around room temperatures have been found to be speeded from 1.6 to 4.0 times by an increase of only 15 to 20°F., simply because increasing temperature produces a rapidly increasing percentage of molecules with energy levels above the minimum needed to produce chemical reaction in a collision.

Jan 1, 1944

By W. W. Eckles

This paper is presented as a suniniary report of the use of well gas composition correlations obtained from mass spectrometer recordings as a means of identification and determination of reservoir continuity. Conventional methods for detecting composition differences are en-pensive, elaborate, and difficult to obtain. This excludes the use of extensive composition data for most applications. During recent years the mass spec-trometer has come into general use as an analytical tool in petroleum refineries. The use of mass spectrometer composition patterns ir~ characterizing or "finger-printing" the produced gas from a reservoir, presents a novel method for correlatitlg gas samples from well to well. The mass spectrometer provides a trace similar to an electric log. having peaks which represent the abuntlnnce of certaitz hydrocarbons in the well gas sample. Without going further into the detailed analysis the idea has been advanced that these traces or patterns could be used as a means of identifying a particular natural gas. This theory has proven to be essentially correct. The mass spectrometer pattern method is simple and cheap as COi?7pared to other standard methods. It greatly facilitates the solution of reservoir and geological problems in which correlation of well gas Com-positions is a factor. Specific field applications have been made. This paper concerns the results obtained in 465 individual gas analyses from 35 fields and 77 res- ervoirs. In a number of cases it has been found that such data have been extremely valuable in the determination of reservoir continuity. In at least one case, the method was a valuable contribution in tracing a reservoir from sand to sand in a coinplex fnulted field involving n11rnerous gas reservoirs. Field applications are presented to illustrate the possibilities of the method at the present stage of developnient and to stimulate the ernployrnent of this new approach by geologists and petroleum engineers in the industry. INTRODUCTION Identification of producing horizons and the determination of reservoir continuity are often a problem in those areas where dome structures and highly faulted sands are encountered. To complicate the picture further, there may be numerous sands, one on top of the other which dip and diverge in different directions. Even though it may be possible to develop some solutions to the preceding problems on the basis of the geological and reservoir data on hand. it is readily recognized that substantiating data based on independent methods would he extremely valuable. It has been found through field studies that correiation of well gas composition can be used to advantage in the geological and engineering study of a complex reservoir identification problem. METHOD FOR COMPARISON AND CORRELATION OF WELL GAS SAMPLES Since a large number of well gas samples are required in a gas identification or reservoir con- tinuity problem, it is necessary that a method of analysis be employed which can detect differences in composition readily and inexpensively. Although detection would be possible by means of low temperature fractional distillation (POD) analpsis, the method requires a relatively large sample and is comparatively slow and expensive to run. The mass spectrometer affords an inexpensive and precise analysis of small well gas samples taken at the surface which are about 1/300 as large as a POD sample. These samples can be obtained by regular field personnei and shipped to the spectrometer for analysis. It is, therefore, a practical approach to the problem. A typical record from the mass spectrometer is illustrated in Fig. I. The peaks on the record represent the abundance of ions produced from the different hydrocarbon molecules making up the gas sam-ple. In well gas comparisons only five peaks are employed, since the other peaks are formed from the same gas molecules and furnish no additional information. The five peaks used represent the abundance of methane, propane, ethane, butane and heavier, and oxygen. They are referred to respectively as the 16, 29, 30, 43, and 32 peaks. The oxygen peak is used to correct for air content in

Jan 1, 1958

By R. H. Hiltz, N. J. Grant

Solid-solution titanium-cerium alloys, cold-rolled to 0.010 in. thickness, and annealed, were internally oxidized to produce a fine dispersion of CeO2 in the titanium matrix. The oxidized alloys were cut into sheet stress-rupture specimens and tested for rupture life at 426°C, 538°C, and 648°C. There was noted an improvement in strength over that of pure titanium, the internally-oxidized alloys showing curves with a much flatter slope on the log stress—log rupture life plot, characteristic of the stable metal-metal oxide class of alloy. DURING the past 3 to 4-year period, considerable interest has been aroused by the potential offered by alloys based on the ultra fine dispersion of a hard insoluble phase in pure metals or solid-solution alloys for use at high temperatures. The impetus to the development and study of such alloys was provided by Irmann.1,2 through the success of the SAP alloy (pure aluminum containing about 12-14 volume pct of A12O3). Subsequent studies have thrown light on the true potential of this class of alloys in the remarkable stability of the structure after long-time exposure at high stresses and high temperatures.a-5 While success has been demonstrated in the special case of the A1-Al2O3 alloys, and more recently

Jan 1, 1959

By C. G. Dunn, J. L. Walter

The c/laracterzstics of cube-oriented nuclei ard other matrix grains that are associated with secondary, recrystallization to the cube texture in high-purity silicon iron were investigated by me-tallographic and X-ray methods. The results show that the structure consists of relatively perfect grains of average diameter between one and two times the sheet thickness ad that the texture has a moderately strong (110) [001] component and a weak (100) [001] component. The results also indicate that matrix stability results from the two-dimensional nuture of the graitzs and that cube-orzented nuclei are neither more Perfect nor larger grains than other matrix grains but have a preferred [001] direction in the rolling direction and have a more effective driving force for growth than other grains because of a low (100) surface energy. THE structures and textures of fine-grained rnatrices determine to a large extent the kinds of secondary recrystallization textures that form on annealing. The understanding of secondary recrystallization processes therefore depends on adequate information about the initial matrices. Matrices usually have three characteristics: 1) they consist of fine-grained primary recrystallization structures, 2) the fine-grained structures are stable toward normal grain growth, and 3) they contain secondary recrystallization nuclei. Stability toward normal grain growth may be due to either a strong single orientation texture (texture inhibition)' or a dispersed second phase (dispersed phase inhibition).2"4 If normal grain growth is not inhibited by either of these two factors, it nevertheless stops when the average grain size is between one and two times the sheet thick- ness.5 This thickness effect satisfies one of the characteristics of a matrix for secondary recrystallization. Its importance in the development of the cube texture in high-purity silicon iron by secondary recrystallization was pointed out by the authors in a recent paper on tertiary recrystallization7 and will be discussed further in the present paper. Assmus, Detert, and he8 have provided some information on a matrix for secondary recrystallization to the cube texture in silicon iron. They found a (110)[001] or Goss texture with enough spread about the rolling direction to include a small amount of the (100)[00l] orientation. The distribution of the [00l] directions was strongest parallel to the rolling direction for both (100) primaries and cube secondaries. These authors found no correlation between size of a matrix grain and orientation and concluded that some property other than size must be the distinguishing characteristic of the cube-oriented nucleus. No consideration was given, it

Jan 1, 1961

By R. J. Teitel

The Pb-U system has been investigated by X-ray, thermal, and microscopic analyses. Two pyrophoric intermetallic compounds were found; UPb3 and UPb. The crystallographic structure of UPb3 is reported. A phase diagram was drawn for the system showing three eutectic and one syntectic reaction. AS a result of the interest in uranium metallurgy, the Pb-U system has been investigated. Practically no quantitative data appears in the literature concerning this system. Chips were machined from bars of high-purity uranium obtained from Ames Laboratory and the lead was 99.9 pct high-purity grade from Bel-mont Smelting & Refining Co. The chips were pickled in a dilute solution of nitric acid, washed in water and then alcohol, and dried prior to use for alloy preparation. The lead was simply sheared from the pig with no chemical treatment. Lead and uranium were placed in graphite crucibles and loaded into an induction furnace. In order to insure good alloy formation, the lead was loaded above the uranium to wash the uranium chips into the melt. After the charge was held at the desired preparation temperature for 15 to 30 min, it was allowed to cool in the crucible. The entire melting operation was accomplished in an atmosphere of helium (double charcoal refined grade with no further treatment). The procedure was to outgas the furnace by first evacuating it to 10-% m Hg, admitting helium to 8 psi gage and sealing the furnace off. An optical pyrometer focused on the charge through a hole in the crucible cover was employed for thermal measurements. Usually a 50° to 70°C correction had to be added to the instrument value. The most suitable alloy preparation temperature range was found between 1220° and 1280°C. The reason for this is explained by the phase diagram, Fig. 7. Above this temperature range two liquids separate preventing alloy formation upon cooling at a reasonable rate. On the other hand, below this range the uranium was coated with a layer of both compounds and the rate of reaction was diminished by diffusion processes. The fastest reaction rate occurred in this narrow range of temperature because only UPb coats the uranium and it evidently does not protect the uranium as well as UPb,. Apparatus and Procedures The development of apparatus and techniques was determined by the peculiar properties of the alloys. All the alloys were pyrophoric, and, consequently, the alloys had to be protected from oxidation by handling them in a dry box or inert atmosphere furnaces. Other operations performed outside of this equipment had to be done as quickly as possible. Thermal analyses were conducted in a furnace and arrangement similar to that described by the author.' Graphite crucibles having a thermocouple well in the bottom were used to contain the prepared alloy, while a helium atmosphere protected the melt from oxidation. The furnace was outgassed by pumping a 10-3 mm Hg vacuum until the furnace had been heated to 400°C. Then helium was admitted and the furnace sealed under 8 psi gage pressure. Chromel-alumel thermocouples were used for thermal analysis and the accuracy of thermal measurements was judged to be k 5°C. At first, an attempt was made to use platinum-platinum-rhodium thermocouples, but evidently lead vapors attack it at high temperatures forming low melting alloys. These lead vapors had direct access to the thermocouple because the graphite crucible was porous. A differential temperature control was used to regulate thermal analyses. The thermal gradient across an alundum tube placed between the windings and the crucible was maintained constant by a controller.

Jan 1, 1953

By R. L. Bleifuss

Most pellets swell only slightly during reduction, but some swell so enormusly that their increase in size is termed catastrophic. Since catastrophic swelling produces irregularities in blast furnace operation, an understanding of the phenomenon is of practical as well as theoretical interest. Observations have shown that catastrophic swelling is characterized by the growth of a network of fine iron filaments. Evidence is presented to show that the growth of these filaments is promoted by the presence of calcium in the magnetite lattice of the original ore. During reduction, the limited mutual solubility of CaO and FeO produces an unstable condition that inhibits the uniform nucleation of metallic iron. Other elements in the magnetite lattice whose oxides are continuously soluble in FeO in the critical temperature range have no effect. Magmatic segregation or pyrometasomatic replacements are the most likely deposits to contain calciferous magnetite. Over the past few years there has been an increasing concern throughout the iron and steel industry over the tendency of pellets to swell during reduction. Although the tendency for swelling is only one of several attributes that determine the behavior of pellets in the blast furnace, swelling-reduction tests are now part of the normal evaluation procedure of many pellet consumers. During a swelling-reduction test, pellets display either the moderate increase in size known as normal swelling, or the enormous expansion known as catastrophic swelling. This paper is concerned with the origin and control of catastrophic swelling and how it is enhanced or inhibited by the presence of minor elements. Swelling Behavior The swelling behavior of pellets during reduction is indicated in Fig. 1. The lower curve represents normal swelling and the upper curve catastrophic swelling.' During the initial stages of reduction, that is, up to about 20-25% reduction, the two curves are considered to be equivalent. Beyond this point normal pellets undergo a gradual decrease in size with increased reduction. By contrast, pellets which exhibit catastrophic swelling show a second dramatic expansion between 25 and 70% reduction. The initial normal swelling develops as the hematite of the pellet is successively reduced to magnetite, and then to wustite. Work by Edstrom' and others has shown that the reduction of hematite to magnetite is accompanied by a 25% volume increase, whereas the magnetite to wustite stage shows a volume decrease. The volume increase overlaps the wustite field because magnetite is formed simultaneously with the wustite during topochemical reduction of the pellet. The catastrophic expansion is clearly related to the wustite, to

Jan 1, 1971

By J. A. B. Forster

The operations of the Electrolytic Zinc Co. of Australasia Ltd. involve the preliminary roasting of zinc concentrate from Broken Hill, New South wales, at a number of acid-making centers on the Australian mainland. The partially roasted material is shipped to the Tasmanian plant where it was formerly re-roasted prior to leaching,' but this practice was gradually abandoned in favor of the flotation of leach residue for the recovery of a concentrate containing about 22 pct sulphide sulphur and known as secontlary or Risdon concentrate.2 This change, together with increased zinc production, called for new furnaces at Risdon for the roasting of 10-50 tonst of secondary concentrcite and 90 tons of new concentrate per day. The war situation made it imperative that construction be commenced without delay and to save time it was decided to base the design on that of Skinner type furnaces which had been built in South Australia twenty years earlier. This involved some sacrifice of desirable features but did not prevent the incorporation of provisions which had enabled small Herreshoff type furnaces to roast secondary concentrate autogenously. The roasting rate in existing furnaces was 10-12 Ib sulphide sulphur per sq ft of hearth area per day, and eleven hearths, 20 ft in diam, were provided in the two new furnaces in anticipation that they would prove capable of the autogenous roasting of 130-140 tons of concentrate per day from 28-29 pct sulphur down to 4.5-5 pct, with an oxidation rate of 11-11.5 lh S/S per sq ft of hearth area per day. It was soon realized, when the first of the furnaces went into operation, that a much better performance than this might be given, and the purpose of this paper is to show how a treatment rate of 100 tons per furnace day, and oxidation rates approaching 15 lb S/S per sq ft per day have been reached. Furnace Design General specifications for the design were based on the results of experience with several other types of furnace and on the special operating conditions

Jan 1, 1950

By Frank T. Sisco, Selma F. Hermann

gancse constituent in the alpha grains. Nickel produces a structure of alpha plus cutectoid almost identical with that of the normal aluminum bronze (Fig. 38), except for the rod-shaped nickel constituent in the alpha grains. Silicon produccs a light structure with small regular needles, possibly a modified form of beta. Fig. 45 shows the alpha plus beta structure of the normal 10 per cent. aluminum alloy as quenched. Manganese produces large grains of beta with alpha as a tiny constituent scattered throughout the spceimen. Silicon, on the other hand, produces all alpha, with free silicon present. One per cent. iron produces alpha plus beta, with a tiny constituent present in the alpha grains. Five per cent. iron introduces twins in the alpha and a nodular iron constituent in both the alpha and the beta. Figs. 50-58 include the structures of the alloys with 8 per cent, aluminum, tempered at 400" C. and at 650" C. Fig. 50 is the normal structure as drawn at 400" C!. It consists of large grains of twinned alpha plus a very small amount of beta. One per cent. silicon increases the amount of beta enormously, but when tempered at 650' C, the beta degenerates to a hard blue network constituent. One per cent. cobalt results in a structure of exceedingly fine-grained, twinned alpha, heavily mottled. Nickel produces large soft grains of alpha with a dot constituent in some of the grains, when tempered at 650" C. Manganese, when tempered at 400" C. produces alpha grains and shows the decom-

Jan 1, 1931

By J. M. Flaitz, A. S. Parks

OF the various methods of sampling gas-condensate wells, a method that secures a continuous representative sample of the well stream is desirable. Such a method, consisting of a sampling tube introduced into the well tubing, has proved satisfactory. The method is sufficiently accurate for operating and engineering problems. A portable testing apparatus can be used with the sampling tube to obtain data useful in studying the economic and technical aspects of the development and operation of gas-condensate properties. INTRODUCTION The recent discovery and development of gas reserves that contain hydrocarbons that condense with reduction of temperature or pressure, or both, to form a product known as condensate, has brought many new problems to the oil and gas industries. With further discovery of deep, high-pressure fields it is presumable that many more gas fields of this type will be added to the steadily increasing number. Such gas reserves are found either associated with oil as a gas cap or in separate formations. There seems to be no positive correlation between the physical or geological nature of the reservoir, and the chemical composition or phase characteristics of its contents. Knowledge of the chemical make-up and phase behavior of gas-condensate reserves are needed to cope with many problems. A knowledge of the chemical composition and phase characteristics of the reservoir material is necessary to properly design a gasoline or recycling plant, to estimate natural gas and condensate reserves, to enable the operator to study the economic and technical aspects of various methods of operation and development, and to carry out the plan of operating subsurface and surface lease equipment. This information is often useful in questions of mineral ownership, proration, legal position, and taxation. It is the purpose of this paper to discuss methods used by the writers to determine the chemical composition and phase characteristics of the fluids produced from a condensate well. The scope of the paper includes a discussion and description of the method of sampling, the results of tests on the accuracy of the sampling method, a description of a portable testing apparatus used to examine the phase characteristics, typical results of tests on wells from several condensate fields, and some of the applications of these data to production problems. References to previous work on this subject are cited at the end of the paper. THE PROBLEM At reservoir conditions of temperature and pressure, the fluids produced from a condensate well exist in a homogeneous vaporous condition. The consequent reduction of temperature and pressure that occurs as this gas enters and flows up the well tube results in condensation of some of the hydrocarbon material to form a liquid. The relative amount of liquid condensed at any point in the flowing system

Jan 1, 1941

By W. A. Mudge, Paul D. Merica

One of the most prominent features of our present-day industrial development is the ever-increasing demand put upon materials of construction. Engineering ingenuity, within the past 25 years, has been unusually active, and in some fields at least engineers frankly say that engineering design has progressed as far as the limitations imposed by the properties of the present materials of construction will permit. Consequently, they are today demanding improvement in their working materials and seeking new ones, through the aid of which the present limitations of design may be overcome. The activity of this search is evident in all fields, but it is particularly so in that of structural materials required to be resistant to corrosion. The corrosion resistance of metals and alloys is never absolute and all-inclusive; a particular alloy will withstand some corrosive conditions well and fail utterly under others. Furthermore, other properties, physical and mechanical, required in conjunction with corrosion resistance vary considerably for different commercial applications. One wants a soft, ductile sheet metal resistant to atmospheric corrosion; another, a high-strength alloy resistant to sulfuric acid. The last decade has witnessed active and definite progress in the development of high-strength, corrosion-resisting alloys. In June, 1924, a symposium by the American Society for Testing Materials, on Corrosion-resistant, Heat-resistant and Electrical-resistance Alloys, disclosed no less than 60 commercial alloys the properties of which were described as being suitable for industrial service where corrosion resistance was a feature. Today the number of these alloys has been doubled, at least. In addition, economy in design and construction through decreased weight has given considerable impetus to the improvement of alloys of which the mechanical propprties may be improved by heat-treatment.

Jan 1, 1935

By Paul D. Merica, W. A. Mudge

One of the most prominent features of our present-day industrial development is the ever-increasing demand put upon materials of construction. Engineering ingenuity, within the past 25 years, has been unusually active, and in some fields at least engineers frankly say that engineering design has progressed as far as the limitations imposed by the properties of the present materials of construction will permit. Consequently, they are today demanding improvement in their working materials and seeking new ones, through the aid of which the present limitations of design may be overcome. The activity of this search is evident in all fields, but it is particularly so in that of structural materials required to be resistant to corrosion. The corrosion resistance of metals and alloys is never absolute and all-inclusive; a particular alloy will withstand some corrosive conditions well and fail utterly under others. Furthermore, other properties, physical and mechanical, required in conjunction with corrosion resistance vary considerably for different commercial applications. One wants a soft, ductile sheet metal resistant to atmospheric corrosion; another, a high-strength alloy resistant to sulfuric acid. The last decade has witnessed active and definite progress in the development of high-strength, corrosion-resisting alloys. In June, 1924, a symposium by the American Society for Testing Materials, on Corrosion-resistant, Heat-resistant and Electrical-resistance Alloys, disclosed no less than 60 commercial alloys the properties of which were described as being suitable for industrial service where corrosion resistance was a feature. Today the number of these alloys has been doubled, at least. In addition, economy in design and construction through decreased weight has given considerable impetus to the improvement of alloys of which the mechanical propprties may be improved by heat-treatment.

Jan 1, 1935

By Eric J. Bradshaw

For several hundred years the petroleum industry has flourished in Burma and at the close of the eighteenth century there were over five hundred producing wells in the Yenangyaung field. These were laboriously dug by hand and were exceedingly primitive, yet even today a small part of India's total production is obtained from hand-dug wells. The Indian Empire, the cradle of the oil industry, today produces but an unimpressive fraction of the world's supply of petroleum, not because the size of her contribution has diminished, but because it has remained more or less stationary while other countries have far outstripped her during the prodigious increase in the world's production of petroleum in recent years. Though for the past 10 years the total production in India has been remarkably constant, it has become increasingly difficult to maintain this output and at any rate from the older fields a slow decline may be anticipated unless new productive horizons are discovered. Production figures for the 10 years 192&1929 (the last year for which figures are available) are given by fields in Table 1. Crudes of Burma and Assam The bulk of India's production comes from the Yenangyaung and Singu fields, from which the crudes are very similar, the only important difference being that the oil from the Singu-Yenangyat structure contains a higher percentage of lighter fractions. The Burma crudes resemble that of the Panhandle of Texas and have a high content of solid paraffin, though strictly speaking the oil is of mixed base with a low content of asphaltum. With the exception of the negligible production from Sabe, the Burma crudes do not require dehydration; the sulfur content is very low and is innocuous. A small amount of naphthenic acids occurs in the kerosene and intermediate oil fractions while the lubricating fraction is practically free from acid. The ash content is low and the average A.P.I. gravity of mixtures of Yenangyaung and Singu oil is 36.4. Burma crudes require only light refinery treatment and practically dl the fractions are merchantable. Part of the gasoline supply is stripped

Jan 1, 1931

By R. L. Loofbourow, Roger V. Pierce

THE degree to which our mineral requirements are being met by mining leaner, more complex or more remote deposits is indicated by developments during 1953. Heavy capital investment, skilled technical advice, planning, and able execution are requirements for the typical venture. Producers, faced with rising costs and with softer prices, are seeking improved mining and recovery. Developments in production of iron ore are typical of the course being followed in metal and nonmetal mining. Iron ore development in the U. S. is concentrated on the spectacular work with Lake Superior taconite, while in Canada new production is expected from Labrador and output from Steep Rock, Algoma, and Newfoundland is being increased. Shipment of iron will soon be made from Venezuela.

Jan 2, 1954

By Edwin Ludlow

THERE has been so much misinformation sent out through the newspapers, and I find so few people who are really acquainted with the true facts in regard to the coal strike, that I feel it would be advan-tageous to present the facts as I have been able to gather them. One of the great points that the miners are now mak-ing is the fact that the operators of the central competi-tive field, consisting of the states of Illinois, Indiana, Ohio and Pennsylvania, have refused to meet them in a joint conference such as has been customary in previous years. There are two reasons why the operators de-clined to hold such a meeting. In the first place, the last time they held a meeting of this kind they were all indicted under the Sherman Act for making an agree-ment in restraint of trade. In the second place, the miners at their convention did not authorize their dele-gates to negotiate a new contract, but instructed them that nothing less than a scale based on the present wage, with the addition that there should be a six-hour day, a five-clay week, time j and a half for over time, and double time for Sundays, would be accepted. These additions would very much increase the cost of coal over the present wage scale. The operators could not consider renewing a contract on the present scale, as it would mean ruin for them, and as the miners were not authorized to negotiate a new scale on a fair basis that would enable the operators to mine coal in competi¬tion, with the open-shop mines the operators did not feel that there was any use in meeting the delegates. Thirty per cent. of the output of bituminous coal comes from the open-shop mines of West Virginia, Alabama and Pennsylvania. During the strike, in 1919, this 30 per cent. was increased to 50 per cent. and it has affected the operations of the union mines to such an extent this year that they have been able to run only 15 to 30 per cent. of their time, while the open shop mines have run from 60 to 80 per cent. as the wages in these mines had been reduced to the 1917 scale.

Jan 5, 1922

By Rollin E. Hook, Attwell M. Adair

The response of CrzO3 and C~304 to various heat treatments was studied in are-melted iodide chromizim over the temperature range 1000" to 1750°C. These oxides, which are present as impurity phases in this material, were identified by X-ray diffraction teclzniques which were supplemented by optical metallop-aphy. As a function of increasing temperature, Crs04 is first observable in samples annealed at 1300°C and coexists with Cr2O3 (the low-temperature oxide) over a temperature range exceeding 200°C. As the temperature decreases, Cr3O4 dissolves with the concomitant precipttation of Cr2Y2. Both oxides precipitate predominantly at pain boundaries. The reactions which occur are involved with at least ternary equilibria, possibly due to iron which is present as an impurity in arc-melted iodide chromium. HILTY, Forgeng, and Folkman' reported in their investigation of the Fe-Cr-0 system that Cr3O4 (with about 8 pct Fe substituted for chromium) is a primary phase found in alloys with 9 or more pct Cr. They reported that this phase is stable only at high temperatures and that below the liquidus Cr3O4 is disproportionated into Cr2O3 and chromium-rich metal for both Fe-Cr-O alloys and in oxygen saturated pure chromium. Further, they proposed that CrsO4 forms by a peritectic reaction between Cr2O3 and the liquid. On the other hand, Hook, Garrett, and Adair2 found in their investigation of impurity phases formed in "pure" chromium (material consolidated from iodide chromium crystals) that Cr3O4 forms intergranularly and is stable as low as 1500°C which is 375OC below the melting point of chromium. The purpose of the research described herein is to determine the temperature range of stability of Cr3O4, and to show the nature of its decomposition. This further investigation indicates that Cr3O4 undoubtedly occurs in this material as low as 1300°C. The chromium studied was consolidated and fabricated from iodide chromium crystals (ICr-5) and contained Fe r 135 ppm, Si = 20 to 100 ppm, and 0 = 35 to 137 ppm. A complete chemical analysis is given elsewhere.' Annealing was conducted in 1 atm of purified helium and all samples were rapidly cooled (-200°C per sec) by withdrawing them from the furnace hot zone under a high flow rate of helium. The details of the electrolytic-etching technique and electrolytic-digestion techniques for preparation of insoluble residues for X-ray examination are given elsewhere also.' EXPERIMENTAL RESULTS The Starting Material. The as-swaged rod (final swaging done at 900°C) had a wrought grain structure and contained a dispersion of CrzO3 inclusions of maximum particle size of about 2 or 3 p, Fig. 1. The microstructure also contained a dispersed

Jan 1, 1964

By C. A. Heiland, Tripp R. M., Dart Wantland

This paper serves to illustrate the application of geophysics to a virtually abandoned mine properly, an application that led to the discovery of an ore body and thus afforded an Opportunity to cOmpare subsequent geologic findings with geophysical data. The work herein described represents, however: more than mere ''case history." It demonstrates that it is possible to obtain satisfactory results by simple means and relatively inexpericnced personnel. The geophysical surveys were made by students as a part of their field assignments in the course of their regular training, and were supervised by Dart Wantland, J. E. Hawkins and R. Maurice 'Tripp. In the course of several seasons an appreciable amount of material was accumulated, which gave graduate students an opportunity for special studies. In this connection, the contributions by L. Massé, R. C. Hyslop, and J. E. Hawkins deserve special mention. The property owners cooperated wholeheartedly in the work, and special thanks are due messrs. J. F. Johnson and S. E. Zelenkov, of the American Smelting and Refining Co., for their interest and for permission to utilize the results of their development work for this publication. Location and Geology The Malachite mine is situated on the northcrn slope of Bear Creek Canyon, 4 miles northeast of Evergreen, I½ miles northwest of Idledale, and 4% miles west northwest of Morrison, in Jefferson County, Colorado. The location (Fig. I) is north of the center of set. 30, T. 45, R. 70 W., at an elevation of about 7500 ft, above sea level, Near the mine the terrain slopes rather uniformly southward at an angle of about 180 pigs. 3 and 7). The geology of the Malachite mine area has been described by J, underhill,' W, Lindgren,2 and J. Boyd.3,4 A map showing surface outcrops and mine workings appears in Fig, 2. the Malachite mine is in an amphibolite belt enclosed in gneisses and schists of the Idaho-Springs formation (probably early Algonkian age). The highly contorted beds are nearly vertical and strike slightly north of west. A series of granite-pegmatite dikes have been intruded almost at right angles into the gneisses and schists and doubtedless are postmineral. While most of the formations are exposed at the surface, a part of the 'lope is covered by slide rock and float, and in the eastern portion by alluvium and creek fill. A quartz-diorite dike cuts through the amphibolite schists at a small angle with nearly vertical dip. The copper sulphides, developed in this dike by magmatic segregation, occur in lenticular form. As far as the mine workings have revealed, the ore lenses are often discontinuous in depth and

Jan 1, 1946

By Tripp R. M., C. A. Heiland, Dart Wantland

This paper serves to illustrate the application of geophysics to a virtually abandoned mine properly, an application that led to the discovery of an ore body and thus afforded an Opportunity to cOmpare subsequent geologic findings with geophysical data. The work herein described represents, however: more than mere ''case history." It demonstrates that it is possible to obtain satisfactory results by simple means and relatively inexpericnced personnel. The geophysical surveys were made by students as a part of their field assignments in the course of their regular training, and were supervised by Dart Wantland, J. E. Hawkins and R. Maurice 'Tripp. In the course of several seasons an appreciable amount of material was accumulated, which gave graduate students an opportunity for special studies. In this connection, the contributions by L. Massé, R. C. Hyslop, and J. E. Hawkins deserve special mention. The property owners cooperated wholeheartedly in the work, and special thanks are due messrs. J. F. Johnson and S. E. Zelenkov, of the American Smelting and Refining Co., for their interest and for permission to utilize the results of their development work for this publication. Location and Geology The Malachite mine is situated on the northcrn slope of Bear Creek Canyon, 4 miles northeast of Evergreen, I½ miles northwest of Idledale, and 4% miles west northwest of Morrison, in Jefferson County, Colorado. The location (Fig. I) is north of the center of set. 30, T. 45, R. 70 W., at an elevation of about 7500 ft, above sea level, Near the mine the terrain slopes rather uniformly southward at an angle of about 180 pigs. 3 and 7). The geology of the Malachite mine area has been described by J, underhill,' W, Lindgren,2 and J. Boyd.3,4 A map showing surface outcrops and mine workings appears in Fig, 2. the Malachite mine is in an amphibolite belt enclosed in gneisses and schists of the Idaho-Springs formation (probably early Algonkian age). The highly contorted beds are nearly vertical and strike slightly north of west. A series of granite-pegmatite dikes have been intruded almost at right angles into the gneisses and schists and doubtedless are postmineral. While most of the formations are exposed at the surface, a part of the 'lope is covered by slide rock and float, and in the eastern portion by alluvium and creek fill. A quartz-diorite dike cuts through the amphibolite schists at a small angle with nearly vertical dip. The copper sulphides, developed in this dike by magmatic segregation, occur in lenticular form. As far as the mine workings have revealed, the ore lenses are often discontinuous in depth and

Jan 1, 1946

By J. M. W. Mackenzie

Recent successful applications of emulsion flotation suggested that a detailed study of some of the physicochemical aspects of the process was warranted. The objective of the current research was to provide general information on the electrokinetic properties of emulsion drops of the type commonly used in oxide mineral flotation. Combinations of the parafin oil Nujol and several long-chain reagents in water were studied with respect to the effect of pH on the surface and zeta potentials. It war concluded that for emulsion drops in the presence of a long-chain reagent but in the absence of any other electrolyte which is adsorbed at the oil-water interface, the surface potential will be some two to four times the value of the zeta potential. During the last decade there has been a revival of interest in the so-called agglomeration, or emulsion flotation (in this paper the term emulsion flotation will be used), process. In this flotation technique, a neutral hydrocarbon oil, together with longcnain reagents, usually of a polar-nonpolar structure, are added to the pulp to function as collectors for specific minerals. The combination of oil and longchain reagent is either emulsified prior to addition to the pulp, or in the pulp itself, and the resulting collector species is an oil-in-water emulsion of a neutral hydrocarbon oil emulsified by polar-nonpolar long-chain reagents. Emulsion flotation has been used successfully in the treatment of ores containing iron, manganese,' and titanium oxides. 2 Two other major and long established applications of emulsion flotation are the flotation of coal and Florida phosphate ores. In recent years, emulsion flotation has been particularly successful in the treatment of ores containing oxide minerals which slime readily and, consequently, are difficult to treat by conventional flotation processes. The recent successful

Jan 1, 1970