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By Arnold M. Lansche

[Selenium and tellurium are rare elements in the earth's crust. Their scarcity and primary dependence of supply on copper and lead output are in consonance with the relatively small quantities consumed at 1964 level. Production depending on output of copper and lead creates a supply situation- which would appear to militate against development of large-scale usage of these elements. However, supplies have adequately met. demand in the past decade and can be increased substantially if warranted by new uses for either selenium or tellurium Ores of copper and lead re the principal sources of selenium and tellurium. Byproducts from the smelting and refining of copper and lead concentrates are incorporated in refinery anode slimes from which selenium and tellurium metal are recovered.]

Jan 1, 1967

By E. R. Landry

This paper reviews the current state of electric furnace technology, with emphasis on some of the more recent developments. A large section of the paper is devoted to the use of increasingly high power inputs by arc furnace operators. Operating practices are then covered, including some of the newer techniques which have been tried.

Jan 1, 1967

By Jack Smith

New turbine blades designed to resist ash erosion were tested by the Bureau of Mines in a pilot-scale coal-fired gas turbine. After a total of 1,963 hours, the rotor blades were only slightly eroded; and they had an estimated useful life of 20,000 to 30,000 hours. Changes in aerodynamic design of the blades successfully concentrated the ash at the outer casing, but stepped sidewalls for the rotor drum and wear strips at the bases of the rotor blades are still needed to minimize wear at these points. Stepped sidewalls and wear strips did not adequately protect the stator blades. Ash slightly eroded their leading edges, above the inserts, and cut notches into their trailing edges near the bases. Stator blade life was estimated at 5,000 to 7,500 hours. Blade erosion in these tests was less severe than with previous designs, but more efficient combustors and ash separators are required to reduce the amount and size of ash entering the turbine, to achieve acceptable blade life for commercial operation.

Jan 1, 1967

By G. L. Gates

The Bureau of Mines in cooperation with the City of Long Beach) Calif.) studied some physical factors effecting the deposition of barium sulfate scale in oil-well rotary pumps. Freshly formed barium sulfate was obtained by combining sulfate in sea water with barium from a barium chloride solution. The rate of scale deposition was measured quantitatively by weighing the pump impellers and diffusers. The results of the tests showed that coating the impellers with plastic significantly reduced the rate of barium sulfate deposition.

Jan 1, 1967

By Adam Chrzanowski, Eugene E. Derenyi, Peter Wilson

"The rapid growth of the mining industry in Canada necessitates a reevaluation of existing mining surveying techniques and the development of new methods. In this connection, the Department of Surveying Engineering at the University of New Brunswick initiated a research program, and the major points of investigation conducted to date are as follows: 1. Based on practical experience and theoretical studies, all factors influencing classical shaft-plumbing procedures were analyzed. Refined methods were developed to increase accuracy. 2. The performance of electronic and optical distance-measuring instruments in underground conditions were investigated. In this connection, test measurements were made in various mines, employing four types of Tellurometers, two models of Geodimeters and a proto-type optical range-finder. 3. Tests were conducted and methods developed for the mapping of large underground chambers by photo-grammetric means. The aforementioned points are discussed at some length in the paper. The authors have also indicated areas where further research is needed and suggested ways and means to improve and modernize mining surveying as a whole throughout Canada."

Jan 1, 1967

By Edward R. Borcherdt

When one considers the advancements made during the 25 years prior to the late fifties, and compares these advances with the progress made in the past decade, the comparison is indeed startling. It was not until 1935 that trucks began to replace rail as a major hauling facility, Initially, the haulage capacity of end dump trucks was limited to 18 or 20 tons. "Straight stick" transmissions were utilized and the available horsepower was minimal. In the early forties single planetary axle 25 ton trucks were introduced, and shortly thereafter those were followed by 35 ton tandem axle units.

Jan 1, 1967

By Neal P. Cochran

The United States is faced with increasing demands for electricity, coupled with continuing demands for crude oil and gas. Superimposed on these' national requirements are our national requirements for clean air and elimination of thermal pollution of our rivers. From the coal viewpoint, this situation is complicated still more by the rapid advances in nuclear power. In this paper, I hope to show a way to use our Western coals as a solution to this involved national problem by producing: 1. High quality crude 2. Low cost power 3. Economic byproducts We could expect these products to be made at one site in an integrated plant that would mine (extract) coal, process it, and convert it to electricity. Perhaps the most important attribute of the plant is its reduced water requirement and the elimination of air pollution from the power cycle. Quite logically, such a plant would probably recover valuable byproducts, such as pipeline gas, sulphur, cement, aluminum, and the like. Although the plant projected in this paper is a conceptual one, it is based on work now underway by Government and industry. Prediction of the future is a most hazardous occupation, but plants such as the one projected are based on current knowledge and can be expected to reach commercial operation in the near term future.

Jan 1, 1967

By C. W. Eggert

This paper gives an account of the E.V.O.P. tests made at the Copper Rand mill of the Patino Mining Corporation in Chibougamau, Quebec. The runs were made to acquire an understanding of the method. A description of events, along with conclusions, observations and opinions, is out-lined.

Jan 1, 1967

By D. R. E. Whitmore, J. M. Harrison

There are five logical stages in the search for orebodies in virgin territory, namely: (1) reconnaissance inventory of geology, and related investigations; (2) development of broad concepts as a basis for selecting regions of potential mineral deposits; (3) assessment of criteria leading to specific localities within these regions; (4) geo-physical and geochemical studies that will delineate small anomalous areas; and (5) stripping, drilling or other means of locating ore. In addition, the development of new means of extracting mineral resources and the finding of new uses play a vital role in our mineral industry. The continued growth of this industry will be largely governed by our ability to develop or to adapt new concepts and techniques, and to produce a greater number of scientists and engineers. It should always be remembered that more than one-third of Canada's exports are dependent upon our ability to find, develop and economic-ally exploit new orebodies.

Jan 1, 1967

By Richard L. Ash

Usually stresses generated by explosive charges during blasting are considered to propagate through materials in a spherical manner. Although conical stress-waves had been suggested by a few investigators they have never been clearly defined or critically observed. An experimental technique using models and lengths of Mild Detonating Fuse was developed to produce conical stress-waves and study their effects. Several materials with different properties were tested to compare the influence of those properties on wave shape and crater formation. The investigations showed that whenever column charges were end-initiated, conical stress-forms were produced if the explosive's velocity exceeded the energy propagation velocity of the surrounding material. The stress-cone angle significantly affected fragment size and shape as well as the geometry of craters produced.

Jan 1, 1967

By Mark E. Emerson

1967 will be remembered as the year the world realized it was running out of silver. In May of this year a new era in tin the history of the white metal was begun as the power of the U.S. Treasury to regulate world .silver markets was staggered by one of the most intense speculative flurries in recent times. In the past few months the price of silver has risen from $1, 29 to over $1.80 per troy ounce and with it have spiraled the prices of a host of silver-bearing consumer items. Legislation has, been enacted to conserve our coinage and meager silver stocks and today large quantities of non-existent silver are trading hands at a fast pace on the commodity exchanges throughout the world. Now that the price of silver has been set loose, forces are in motion to dull the world's appetite for silver. At the same time there is strong incentive to provide greater quantities of silver to satisfy the world's hunger' for the metal.

Jan 1, 1967

By Norman F. Schulz

Representative sample s of typical manganiferous iron ores from the Cuyuna Range, Minnesota, were reduced to the metallic iron state at temperatures just short of fusion with an excess of coke in the manner prescribed by the R-N Direct Reduction Process. The magnetic separation characteristics of the reduced ores were determined at several grinds by means of the Davis magnetic tube concentrator. The efficiency of metallic iron concentration by magnetic separation was a direct function of the degree of metallization of the ore sample and of the degree of liberation attained in grinding. Some improvement of liberation characteristics was observed if a small amount of sodium chloride was present in the ore during reduction. Despite the extremely fine -grained structure of the crude ores, iron concentrates containing more than 90% Fe at iron unit recoveries of 90% or more were obtained from well-metallized samples of three of the four ores tested. The rejection of manganese to the tailings corresponding to such separations varied from 80 to 95%.

Jan 1, 1967

By B. G. Agnew

In evaluating fracture treatments, the need to answer such questions as "What zone or zones were actually treated?" and "What was the vertical extent of the treatment" is necessary, since determining effectiveness of the fracture treatwrent depends on knowledge of the reservoir portions stimulated and the vertical extent of the fracture system or systems. Injection of hot or cold fluids during fracturing operations will transfer heat to the surrounding formations and fracture faces mainly by heat conduction. Once injection ceases, temperature anomalies will develop opposite the zone fractured because the rate of temperature decay is less than that opposite zones heated or cooled by flow inside the wellbore or along the cement sheath. Thus, temperature surveys can he used to determine where fractures were generated outside the wellbore and to reasonahly estimate the vertical extent of the fractrires. This technique has been used successfully to evaluate over 344 fracture treatments at depths ranging from 1,500 to 15,700 ft. Examples of actual temperature surveys are presented to show how this method of fracture treatment evaluation can be used effectively and beneficially. INTRODUCTION Stimulation of producing or injection wells by fracturing is commonplace in the industry today. In evaluating these treatments, two basic questions which arise are "What zone or zones were actually stimulated?" and "What was the vertical extent of the treatment?". Knowledge of the reservoir portions stimulated and vertical extent of the fracture system or systems is vital to effect efficient and economical well completions and to assure maximum recovery from reservoirs. Not all fracture treatments are successful and many times the desired or anticipated results are not achieved. When this occurs, it is in most cases the engineer's job to determine why. The answer to this problem forms the primary basis for deciding whether to spend more money for development drilling and/or completion attempts or to forego additional expenditures to improve the particular zone. Also, knowledge of the reservoir portion actually stimulated is invaluable in planning future workovers. This is especially true in wells producing from reservoirs containing multiple porosity stringers or zones. For various reasons, all zones within a reservoir may not be perforated on initial completion with the thought of developing remaining zones through future workover operations. Because particular zones are perforated and fracturing fluid pumped down the wellbore, it cannot be assumed that all perforated zones are stimulated, and in turn drained. Occasionally, unperforated zones which are planned for future development are actually stimulated on initial completion. eliminating the need for future recompletion attempts or all zones perforated initially are not stimulated, thus requiring additional completion work to insure that these zones are adequately drained. In most cases, it is costly. if not impossible, to determine with assurance why a fracture treatment is unsuccessful after the job has been completed and the results tested. Further, unpredictable upper and lower fracture barriers. as well as possible borehole communications (cement channels), do not permit it to be taken for granted that the formation opposite the perforations is the only zone receiving the fracture treatment. Thus. evaluation of fracture treatments is necessary for efficient and prudent well completion practices and should be done simultaneously with the fracture job. Several methods have been used to locate fractured zones, all of which are based on detection of radioactive tracer materials added to either the fracturing fluid or the propping agent. These methods have been helpful in increasing knowledge of fracturing operations; however, they are seriously limited because of cost and inability to detect accurately radioactive tracer material more than a few inches away from the borehole. To develop a better diagnostic tool to pinpoint which zone or zones had actually been fractured, temperature surveys were run after fracturing with heated and cooled fluids. Significant temperature anomalies were found to exist opposite zones suspected of receiving the fracture treatment. From the analysis and examples to be shown, it can be seen that temperature surveys run in a stabilized wellbore several hours after a fracture treatment using hot or cold fluid will yield temperature anomalies which show the actual reservoir portion stimulated, the vertical extent of the fracture system or systems and a qualitative indication of the portion of fracture-fluid volume entering a given depth interval. The experience and illustrations used in this paper are based on evaluation of over 344 fracture treatments during the past three years using this diagnostic tool at depths ranging from 1.500 to 15,700 ft and fracture volumes ranging from 2.000 to 110.000 gal. Based on analyses of these temperature surveys, analyses of fracture gradients and evaluation of several open-hole packer impressions in the West Texas area,' vertical fracturing is the predominant mechanism and horizontal fractures occurred frequently, if at all.

Jan 1, 1967

By A. Bauer, P. Calder, N. H. Carr, G. R. Harris

Since both rotary and jet piercing drills are used by the Iron Ore Co. at Smallwood, it is often desirable in planning to know in which regions of the orebody or new orebodies a particular drill will be the most economic. This makes it necessary to establish a correlation between drillability and pierceability and some physical rock properties. For rotary drills a good correlation was found with penetration rate and grinding factor index. The jet piercers were found to have a reciprocal relationship in the sense that the best rotary ground was the worst jet ground and vice versa. It is also indicated how an economic comparison could be made using these penetration rate versus grinding factor index curves, the hole size distribution curves for single pass and chambered holes and the mine distribution curve for grinding factor index. A discussion is presented on the fuel oxygen ratios to be used in jet piercing and on the site gas sampling and analysis which has been used to set up the drills. The fuel has been cut back so that stoichio-metric conditions exist, carbon monoxide is drastically reduced and pop-up or exploding holes eliminated. No decrease in penetration rate has been observed contrary to the published results of previous workers. The blasting procedure and results at Smallwood are discussed and the operation of Iron Ore Co.'s slurry pump-mix truck is also described briefly. Smallwood mine is part of the Iron Ore Co.'s Carol Lake operation and is situated in Labrador, 240 miles north of Sept-Iles, Quebec. Last year 15 million tons of crude ore were crushed to yield 6.3 million tons of concentrate and pellets. This year the figures will be 17 million tons of crude and 7% million tons of concentrate and pellets which is the full plant capacity. Carol Lake ores consist primarily of specularite and magnetite mixed with quartz. For convenience the ore has been split-into the following classifications depending on the percentage of magnetics in the sample, shown in brackets: specularite (0 to 10%), specularite-magnetite (10 to 20%), magnetite- specularite (20 to 30%), magnetite (>30%). The order of classification also represents the order of increasing grinding difficulty - the specularite generally being the easiest and the magnetite the hardest. The orebody also contains a small percentage of waste materials consisting of limonite carbonate, quartz carbonate and quartz magnetite. The first two materials are among the softest in the mine, generally softer than the specularite, and the quartz magnetite is amongst the hardest. The bulk of the material in the mine is of the specularite-magnetite and magnetite-specularite classifications. As a result of test drilling at Smallwood in 1960 with rotary, jet and percussion drills, the Iron Ore Co. purchased four JPM-4 jet piercers for the bulk of production drilling and set up an oxygen plant to supply 20 tons of oxygen per day. This oxygen is sufficient for two machines operating full time and one part time. In addition, there are two 50-R, one 60-R and one 40-R machines in use. The benches are 45 ft high and 50 ft holes are generally drilled. JET DRILLING At the onset of jet drilling in the late fall of 1962, two major problems were encountered: 1) freezing due to winter operations; experience and the use of heat at more places, such as the rotary head, has eliminated this,'" and 2) exploding or "popping" drilled holes; this happened frequently (several holes "popping" each day) and was the cause of two lost time accidents. In one instance a hole was being measured with a tape which fell down the hole causing it to "pop." Safety glasses though pulverized saved the wearer's eyesight. Various methods were then employed to detonate the holes before measuring or loading (dropping lighted rags of fusees down, or sparking across a spark gap). These methods were time consuming and far from completely successful. Consideration was given to the fuel oxygen ratio on the machines and what this would produce in the way of product gases. A fuel oxygen weight ratio of 0.35 which was quite oxygen negative was being used. Theoretically appreciable carbon monoxide would be produced at this fuel oxygen ratio. On the close down procedure of the jet which calls for low oxygen after flame out, oxygen would be left in the hole along with this carbon monoxide. This is an explosive mixture. The fuel oxygen ratio was cut back to stoichiometric

Jan 1, 1967

By Janos de Warga

"After a short introduction to the history of the semi-conductor theory, the paper describes the principles of electron and hole flow in the semiconducting materials, the operation of the PN junction, and the rectification process in multi-layer devices (diodes and SCR's). The various methods of purification and zone-refining of the silicon are illustrated prior to the discussion on the most commonly used junction-forming processes (alloying, diffusing, etc.). Modern device fabrication and packaging operations are illustrated. Factory testing, evaluation, electrical parameters and guaranteed rating characteristics are listed. It is explained in this paper how the various device parameters affect the electrical performance of the finished unit and how the finished unit characteristics (turn-on, turn-off time, etc.) will influence the equipment rating. In concluding, some typical items of equipment are highlighted, and the applications of these semiconductor rectifiers in the chemical, mining, pulp and paper, and steel industries, etc., are dealt with."

Jan 1, 1967

By John Sasadi

The mining industry depends upon inexpensive water transportation. Today, large quantities of mined products are transported by ships over oceans, from continents to continents, over lakes and waterways to the ultimate users. Sometimes, the routes these Bulk Carriers travel cover only a few hundred miles, sometimes thousands of miles halfway around the world. Most of the products of the mining industries are relatively inexpensive. A significant portion of their cost to the ultimate users are in the cost of transportation and not in loading and unloading these commodities at the ports of origination or destination. So far, the industry has produced very efficient loading and un- loading installations, but has very little influence over marine transportation or the design of the vessels themselves. Very little was ever published dealing with integrated transportation systems properly correlating all phases of the operation; namely, loading, marine transportation and unloading bulk materials.

Jan 1, 1967

By D. J. Crawford

The Lucerne Valley Operations of the Minerals, Pigments and Metals Division of Chas. Pfizer & Co., Inca, are located about 5 miles south of the town of Lucerne Valley, California. These operations consist of several limestone quarries, a whiting plant which produces finely pulverized limestone products, a-kiln which produces granular quicklime and lime products, and maintenance shops, warehousing, shipping, and office facilities. Construction of the Lucerne Valley plant began in 1961 as the result of a decision to utilize large undeveloped reserves of limestone in that area. Quarry development was started in the following year; and by 1965, Lucerne Valley had become the principle limestone and lime facility of the Western Operations of the Minerals, Pigments and Metals Division.

Jan 1, 1967

By P. J. Burkhardt, L. V. Gregor

The oxidation kinetics of single-crystal silicon has been investigated using extremely dry oxygen as the oxidant. Two techniques were used. The first involved a flow system with which incremental thickness measurements were made. This sytem provided an oxygen ambient at atmospheric pressure which had a moisture content of less than 0.1 ppm of water. The second technique involved measuring the change in volume of oxygen with time in a closed system. A temperature range of 900O to 1200 "C and a pressure range of 20 to 760 Tory were covered. Both techniques showed that a simple parabolic rate law holds only at the higher temperatures. At lower temperatures, the data up to 5000Å can be fitted well to a linear-parabolic equation. The two constants in this rate equation are examined in terms of a physical model. The parabolic portion of the low-temperature oxidatLon fits along the high-temperature curve of an Arrhenius plot. The parabolic rate constant for the flow-system technique can be expressed by k = 2 x 10-9 exp (L 31 kcalRT) sq cm per sec. The manostatic technique gave k = 1 x 10-exp (- 23 kcalRT) sq cm per sec. By extending the thickness range to over 104. a rate law of X = At seems to fit all of the data better than the linear-Pavabolic law. Here the exponent n increases from 0.518 at 1150 V to 0.637 at 900°C. PASSIVATION of silicon planar devices through thermal oxidation is of such great importance that considerable effort has been devoted to the study of the process.17 Much of this work involves hydrothermal oxidation, in which H2O is the oxidant: whereby H2 is produced. It has been proposed that the reaction proceeds by the formation of Si-OH groups and hydroxyl diffusion through the film to react with the silicon surface. Thus, the silicon oxide layer probably contains residual hydrogen in some form after oxidation in H2O and it has already been established that hydrogen has a marked effect on the electronic properties of oxide-passivated silicon surfaces. Silicon is oxidized by oxygen at elevated temperatures; but the rate of oxide formation is considerably lower than that for 0." By using dry O2 as the sole oxidant, the presence of residual hydrogen is presumably avoided. At present, the mechanism of thermal oxidation by dry O2 is a matter for conjecture, and the presence of small amounts of H2O was reported to have a marked effect on the rate of oxide formation10 (perhaps on the electronic properties of the surface, as well). Hence, this study of the kinetics of silicon oxide growth in 0, was undertaken: 1) to determine the oxidation rate at atmospheric pressure in a system designed to exclude rigorously all traces of H2O in the ambient 0,; 2) to obtain oxidation-rate data in situ in dry O2 by means of a continuous monitoring of the amount of 0, consumed during oxide growth. These objectives are complementary—the first assesses what effects (if any) are obtained by excluding H2O from the reaction, and the second expands this information while at the same time avoiding the uncertainty inherent in relying upon incremental measurements of oxide growth to furnish kinetic data. EXPERIMENTAL PROCEDURE The conventional silica open tube in a resistance-heated oxidation furnace is subject to sources of trace H2O, even after the input O2 is thoroughly dried and the outlet gas stream is passed through a trap to prevent

Jan 1, 1967

By R. L. Loofbourow

Reasons for reexamining underground mining include: 1. The assurance that more deep deposits of useful minerals will be found. 2. The existence of deeply covered deposits of industrial minerals near large markets where quarries are becoming depleted or are lacking. 3. Surface property values, zoning and other limitations on open pit mining. 4. Expectation that underground space will be increasingly used for transportation, power plants, storage and similar purposes. 5. The improvements which have been made in underground mining. During the last three or four decades many changes and improvements have been made underground. All underground construction and mining has benefitted to some extent but the effect on the productivity of labor employed with some methods- has changed little and the use of these methods has declined. Productivity of labor in other methods has increased substantially. The relative usefulness of mining methods has changed and a vital industry, bituminous coal, has been returned to health. In this paper, consideration is limited to nine methods used with high productivity during the period under review. These methods are not necessarily better than others but they may be considered the prime methods in the sense that, in our economy, many, low grade ores, coal and the principal industrial minerals could hardly be produced by less productive means.2 Although most of the examples cited are from mining as such., the first four methods discussed can be used for the construction of stable excavations of various' shapes in sound rock.

Jan 1, 1967

By C. N. J. Wagner, E. N. Aqua

The bee alloys of the terminal solid solution of rhenium in niobium were investigated by X-ray diffraclion methods. The analysis of the broadening of the powder pattern peaks from the niobium-rich alloys, cold-worked by filing, showed evidence for faulting on (211) planes. The alloys with larger rhenium concentrations were brittle, and fractured when filed. The analysis of the shapes of the diffraction profiles from powders produced by hammering with steel plates) of these brittle alloys indicated that the broadening was due predominantly to platelets bounded by clibe planes. This result was consistent with the Laue patterns from single-cleazlage facets which showed evidence for clearage fracture on {100} planes. The influence of faulting on the mechanical properties of face-centered cubic (fcc) metals and alloys, i.e., how faulting affects the various dislocation configurations in fcc metals, is well-known.' The important question is whether or not faulting occurs in body-centered cubic (bcc) metals and alloys, and, furthermore, if faulting does occur, to what extent it affects the mechanical properties. Theoretical calculations indicate that the stacking-fault energy is rather high in most bcc metals.2 The results of sev-eral studies using transmission electron microscopy have indicated that faults are present in well-annealed and lightly deformed bcc metals and alloys, such as tungsten,3 vanadium,4 and Mo-Re alloys.5,6 These faults, as have been observed, may be stabilized by the presence of interstitial (C,N,O) atom segregation to the extended dislocations. In addition, there is considerable X-ray diffraction evidence for faulting in bee metals,7-8 using the same techniques that were successful for the study of faulting in fee metals and alloys.7 This X-ray diffraction method is currently the only technique applicable for the investigation of faulting in metals with high stacking fault energies, i.e., when severe amounts of deformation are required to produce sufficient amounts of faulting to be detectable by X-rays. The thinned films of heavily deformed metals will become opaque in the electron microscope due to the high dislocation densities present. In a previous investigation of faulting8 in bee metals of group Vb and VIb, the authors observed that niobium was ductile when filed at room temperature, and showed the highest density of faults on the (112) family of planes. A niobium-base alloy system was therefore chosen to study the effect of alloying on the occurrence of faults in a bcc alloy. There is a large range of terminal solid solubility of rhenium in the alloys of the bee refractory metals. All of the Group VIb-rhenium alloys, i.e., Cr-Re, Mo-Re, and W-Re, exhibit solid solution hardening without loss of ductility.9 In fact, the ductility reaches a maximum for alloys with compositions near to the limits of solubility. This enhanced ductility has been attributed to the lowering of the stacking-fault energy in the alloy; i.e., the increased amounts of twinning provide an additional mode of deformation, resulting in the observed high ductility.' Because of this demonstrated effect of rhenium in bee alloys, it was decided to study a series of alloys of Nb-Re. Using the same X-ray diffraction methods as described in the previous investigation,' one is able to identify the possible causes of broadening of the powder pattern peaks, e.q., particle size, microstrains, stacking faults, and/or twin faults. The separation of these various contributions to the measured peak shape is accomplished by the Warren-Averbach analysis.7 I) EXPERIMENTAL PROCEDURE A series of seven bee solid solution alloys containing from 2.5 to 21.5 at. pct Re (remainder niobium) were prepared at the General Electric Research Laboratory. Buttons, weighing 25 g, were alloyed from electron-beam-melted niobium chips and random rhenium sheet by arc melting in a water-cooled copper crucible, under an argon atmosphere. The buttons were inverted and completely remelted to promote homogenization. The nominal alloy compositions are listed in Table I. Samples of the cold-worked alloys were obtained by filing to produce a powder for the X-ray study. Alloys too brittle to be filed were hammered with steel plates. The resultant filings or brittle impactings were screened through 150-mesh classifiers and compacted to the required shape for the diffractometer holder. The X-ray diffraction peaks were automatically recorded by fixed time counting at uniform 28 intervals, or by continuous registration with a ratemeter. In all cases, the (110)-(220) and (200)-(400) pairs of peaks and the (211), (310), (222), and (321) reflections were measured on a GE-XRD5 diffractometer using CuKa radiation with nickel filter or MoKct radiation and a LiF monochromator in the diffracted beam. The first part of the data reduction, completed with the aid of a series of programmed computations,10 was the analytical resolution of the Kol component of the diffraction profile. Subsequent computations were then made with reference only to the resolved Kol peak shape. These included the measurement of the

Jan 1, 1967