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By R. W. Diamond

THREE mills are now operated by the Consolidated Mining & Smelting Co. of Canada, Ltd. : (1) The Sullivan Concentrator, Chapman Camp, B. C. (near Kimberley, B. C.), (2) the St. Eugene Concentrator, Moyie, B. C., and (3) the Tadanac (Customs) Concentrator, Trail, B. C. Differential flotation is the only concentration method employed in all three I plants. Tables are used for pilot work only. Values in all ores treated are as minerals of some or all of the metals -lead, zinc, gold or silver. Occasional customs ores contain small amounts of copper. Sulfide iron content of ores treated varies from a [ ] low figure in some ores to 38 per cent. iron in Sullivan ore. Gangue minerals vary considerably. A few customs ores are somewhat oxidized and as a result present difficulties. Flotation equipment and control are similar in the three mills, and the flow sheets at the St. Eugene and Tadanac mills, while much simpler, are modeled after that of the Sullivan Concentrator. In this paper I will not detail treatment nor equipment in any of our plants but will describe special features in, or in connection with, all of them. I will then deal with flotation reagents, describing our use of each of them, particularly where differing from general practice. I will conclude with comments on special subjects related to differential flotation.

Jan 1, 1928

By M. J. Buerger

POSSIBLY the most puzzling features observed during a single-crystal deformation test are the appearance of slip striae on the surface of the crystal and the strengthening of the specimen.1 While the first phenomenon is mainly of theoretical interest, the latter is fundamental to all strain-hardening and cold-working processes in which the deformation occurs by translation. The plastic deformation of crystals has received considerable discussion2 and need not be reviewed here in, any great detail. It has been observed, essentially, that after a certain amount of initial stress is applied, the surface of the crystal becomes covered with sets of parallel striae or rings which appear to divide it into thin slabs or slip blocks.3 The striae are the traces of rational crystallographic planes along which shearing movements are localized, these movements providing the strain which accompanies stress applied beyond pure elasticity. As deformation under the applied stress proceeds the slip blocks shear past one another, although the essentially single-crystal character of the specimen is unimpaired. All of the shearing apparently takes place in the immediate vicinity of the original slip striae without the appearance of new planes of movement.4 Since each increment of strain is attended by an increased stress requirement to continue the deformation, the crystal strengthens during the process.

Jan 1, 1928

By James R. Cost

The increasing emphasis upon the use of refractory metals has resulted in a closer look at some of the properties of these materials. In the course of a study of the Nb-N system it became necessary to re-examine one such property, the spectral emissivity, e. Experiments were performed in order to determine e for solid niobium as a function of both temperature and nitrogen content. The results of these experiments, which indicate a small but significant correction to the spectral emissivity of pure niobium, are reported herein. In addition, data on the total emissivity, et, of niobium and the spectral emissivity of the nitride Nb2N are given. To this author's knowledge, neither of these emissivities are as yet reported in the literature. Previous studies of the spectral emissivity of niobium have been few. In 1915, Burgess and Waltenburgl obtained a value of 0.49. Whitney? in 1935, used a Mendenhall V to obtain the commonly accepted value of 0.374. A recent investigation of sintering of niobium graphically reported a value of about 0.36= using a solid block of the metal with a blackbody hole drilled into it. In the present experiment a method similar to that of Worthing4 was used. An 8-in. long and 3/16 in. diam hollow tube was formed from smooth surfaced 0.0013-

Jan 1, 1962

By R. G. McQueen, E. G. Zukas

THE production of isotropic fine-grained ingot iron would be most useful since physical measurements associated with the elastic properties of iron are influenced by the size and orientation of the individual grains. This can be accomplished at present for small samples by established metallurgical procedures, but for large samples (in excess of 2 in. diam by 1 in. thick) it is virtually impossible to produce reasonably small uniform grains with random orientation. Such pieces can, however, be produced by impulsive loading followed by a suitable recrystallization treatment. The shock loading system employed is diagrammed in Fig. l. Here the 3/8-in. iron plate is accelerated by the plane-wave initiated high explosive charge through a 1 5/8-in. air space. Collision of this plate and the specimen of interest generates a shock wave in excess of 300 kbars which passes through the specimen. For this type of work it is not necessary to use machined parts: for example, the ingot iron pieces are saw cut from the billet so that they can be inserted in short sections of iron pipe. The recovered specimens are less distorted, however, if the air gap between the iron sample and pipe is filled with Woods metal. The dimensional changes resulting from this type of loading technique are minor, usually less than a 10 pct reduction in thickness. Compressive yield

Jan 1, 1962

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

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

Jan 1, 1941

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

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

Jan 1, 1941

In accordance with the requirements of By-Law LX,- I beg leave to submit herewith the report of the Library Committee for the year 1916. The activities shown by the sale of the Institute's publications during the year are somewhat larger than last year, due principally to the increased sale of special editions on account of the larger sale of the Posepny and Emmons Volumes, owing to increased advertising and to the reduction in price of the Emmons Volume. The sales were distributed as follows: Sale of Transactions $3,237.07 Sale of Special Editions 1,722.50 Sale of Bulletins and Pamphlets 2,263.95 Total $7,223.52, The Institute library has now been merged with the libraries of the. other three Founder Societies and is known and administered as the Library of the United - Engineering Society. When this merger, was effected, a proviso was made that the books contained in the Institute library up to the date of the merger were still to be considered as the individual property of the Institute, and this arrangement applied also to the libraries of the other two Founder Societies. At the time that the American Society of Civil Engineers joined as a fourth Founder Society, they immediately turned over their entire library to the United Engineering Society, relinquishing all property rights in the books entirely.

Jan 2, 1917

By Anders Carlson

NOTABLE advances have been made in the evaluation of oil-reservoir rocks from information furnished by core analysis. Among the physical data employed, per-meability is of primary importance. It may be assumed that the permeability of a core sample, considered as a property inherent to the nature of the porous medium only, is not markedly altered by the coring opera-tion, therefore some degree of accuracy is justified in the laboratory determination of permeability constants by means of homo-geneous flow media. To provide that such relatively simple determinations be sus-ceptible to duplication and consistent inter-pretation should prove advantageous in the prediction of subsurface flow conditions involving nonhomogeneous fluids. The air permeameter seems to fill most satisfactorily the need for rapid and fairly accurate determinations. Instruments that are similar in design and operation have come into general use. However, this has not resulted in an encouraging uniformity in the results obtained. Recognizing the value of reducing measured values to a common quantitative standard, the authors have sought to determine possible reasons for undue discrepancies and means for their elimination. This paper will be specifically concerned with three factors, which appear to be of some importance in the establishment of consistent permeability values: (I) design and operation of the permeameter, (2) preparation and mounting of the sample, (3) type of flow created in the sample.

Jan 1, 1940

By E. A. Devuyst, M. A. Mosoiu, V. A. Ettel

Nickelic hydroxide is an important metallurgical reagent used for precipitating cobalt from nickel sulfate solutions. Existing methods of preparation of nickelic hydroxide involve electrolytic oxidation of Ni(OH)2 or the use of strong oxidizing agents such as chlorine, ozone and persulfate. Although the oxidizing properties of the SO2 + O2 system have been known for some time, e.g., detection of SO2 and oxidation on iron in acidic solution, the application of this system for the preparation of nickelic hydroxide as a process was not considered in the past. The present paper describes a new method for chemical preparation of nickelic hydroxide which has been developed in INCO laboratories. The technique consists of reacting nickelous hydroxide suspensions with a slurry of calcium sulfite in the presence of air or oxygen. The main advantage of the process is the cost of reagents and an absence of soluble by-products (e.g., C1-). The chemistry of this process is unusual since the redox potential obtained during the reaction exceeds that of the oxygen electrode. Therefore, the effect of CaS03 is not just a catalytic acceleration of the reaction NI(OH)~ + 02. The so3= must be involved in the stoichiometry of the overall reaction producing in the initla1 phase some strongly oxidizing intermediate species.

Jan 1, 1981

By Herbert E. Lindberg

Laboratory-scale intact and jointed rock masses were tested in field and laboratory experiments to investigate tunnel response in high stress environments. In most of the experiments the tunnels were modeled by a rigid-plastic foam polyurethane with a crush strength of 3.4 MPa (500 psi) and emphasis was placed on jointed rock parameters: joint sets (single set of parallel plane joints versus a double set of orthogonal parallel plane joints), joint plane angle with respect to the direct loading direction, and joint spacing. Other parameters were loading stress, loading direction, and tunnel reinforcement strength. Results show quantitatively the increase in tunnel deformation in jointed compared with intact rocks, double versus single joint sets, and large versus small angle between the joint plane normal and the loading direction. A surprising result was the decreases in tunnel deformation with increases in the number of joints across a tunnel diameter. The efficacy of scale modeling with laboratory-constructed rock was tested by modeling complex reinforced concrete and steel tunnel reinforcements in jointed rock masses and comparing the results with large scale tunnels previously fielded in highly jointed granite. Tunnel response was reproduced in surprising detail, including concrete fracture, steel liner bending and fracture, and critical load to produce these responses. The scale models also allowed sectioning of the jointed rock masses to observe gross sliding along the joints that accompanied tunnel failure.

Jan 1, 1982

By S. Frederick Ravitz

IN recent years, two theories of the mechanism of flotation have received a great amount of attention. One of these is Ostwald's theory of linear flotation,1 according to which most collectors contain three active groups: a hydrophilic or water-loving, a metallophilic or mineral-loving, and an aerophilic or air-loving group. Under the action of these three groups, Ostwald considers a single ring of collector molecules at the three-phase air-liquid-mineral boundary sufficient to bring about the flotation of the mineral particle. Siedler, Moeller and Reddehase2 objected to this theory immediately after it was presented, but most of their objections were answered by Ostwald.3 Very recently, however, Wark and Cox4 have more adequately criticized this theory, and their criticism makes its validity appear doubtful. The other important recent theory is the "chemical" theory of flotation, proposed by Taggart and his coworkers,5 who maintain that "all dissolved flotation reagents, which, in flotation pulps, either by action on the to-be-floated or on thenot-to-be-floated particles affect their floatability, function by reason of chemical reactions of well recognized types between the reagent and the particle affected." In general, they appear to consider most flotation results to be brought about by purely chemical reactions between the collectors and the products of oxidation present

Jan 1, 1933

By Max W. Bowen, A. J. Weinig

The important part that dissolved oxygen plays in the cyanide treatment of gold and silver ores is commonly recognized by most metallurgists and mill men. But heretofore there has been no simple method on which the mill man could rely for determining the amount of oxygen in the various mill solutions. A few methods are adaptable to the laboratory, such as the gasometric1 determination by actually measuring the oxygen, Winkler's2 iodometric method, and Schutzenberger's3 method, which depends on the reducing action of sodium hyposulfite on a blue solution of indigo carmine; but these are not readily adaptable to the needs of the mill man and cannot be applied to cyanide solutions without modification. The gasometric method is the most accurate but it takes too long to complete a determination. White's4 method (a colorimetric method that depends on the degree of coloration imparted to a solution of pyro-gallic acid in the presence of caustic soda) although much more rapid than any of the methods named, often gives misleading results on account of grading of colors of different solutions, which nearly always contain various kinds of salts. The method herein described was devised for the use of the mill man, the aim being to develop a simple, practical, accurate method. It is a modification of the Schutzenberger method and depends on the reducing

Jan 1, 1925

By D. D. Pollock

The resistivity, temperature coefficient of resistance, and absolute thermoelectric properties of some binary terminal solid solutions of silver were determined. Equations are given which permit the calculation of these properties. CONSIDERABLE work has been done on the constitution and electrical conductivity of binary alloys of silver.1-l2 Some of these alloy studies are apparently complicated by doubtful chemical analyses. In some cases the limits of solid solubility are questionable. Those references which present electrical properties of binary silver alloys usually give just one particular set of characteristics such as conductivity (or resistivity). As a means of checking and extending this earlier work, an investigation was undertaken to describe and calculate the resistivity, temperature coefficient of resistance, and thermoelectric power of binary terminal solid solutions of silver. PREPARATION OF ALLOYS All of the alloys were made with silver containing less than 0.014 pet (by weight) of impurities. These materials were carefully weighed out into 225-g heats and melted in a high-frequency induction furnace. The indium, tin, and antimony systems were melted in Al2O3 crucibles, under a boric anhydride cover, and poured into split graphite finger molds. The aluminum, germanium, arsenic, lead, and bismuth alloys were melted in machined graphite crucibles, and they were also covered with boric anhydride and poured into split graphite finger molds. The alloys containing magnesium and manganese

Jan 1, 1964

By J. C. F. Randolph

New Granada, or, as it is known to its people, the Republic of Colombia, occupies the northwest corner of South America, and includes the Isthmus of Panama. Although it is one of our nearest neighbors, so little is known about it in the United States that the following notes regarding it, flowing from a year's professional residence, may be timely. It is bounded on the north by the Caribbean Sea and Costa Rica, on the east by Venezuela and Brazil, on the south by Brazil and Ecuador, and on the west by the Pacific Ocean. Its extreme geographical limits are from 2' South latitude to 12' North latitude, and from 69 to 78' East longitude. In size, therefore, it is roughly 1000 miles from north to south, and 600 miles from east to west. After many political convulsions and revolutions, and a somewhat checkered history, the country consists to-day of nine departments, Panama, Bolivar, Magdalena, Cauca, Santander, Antioquia, Tolima, Boyaca and Cundinamarca. These departments are governed from the national capital of Bogota, although each has its own capital and departmental staff. The total population of the Republic is not more than 3,000,000 inhabitants, and these to a large extent consist of mixed races. Those who live in the hot belt are, as a

Jan 1, 1890

By Charles Y. Clayton

THE general public does not know that there is such a thing as metallurgy and it is very seldom that you see the word metallurgy in print except in technical magazines. Perhaps it is more to the front now than in former years; the Dee. 30, 1929, issue of Time mentioned under the heading of "Science7' certain new achievements in metallurgy, which may be cited as a rare instance of the use of the word in anything but the technical press. Too often the part the metallurgist plays in the advancement of the different branches of engineering is overlooked. To say that the public does not know there is such a profession as metallurgical engineering seems to be a bold statement, but had there beep time a questionnaire could have proved this beyond doubt. Suppose a carefully-planned questionnaire had been sent to all high school students asking them, among other questions, to list the different branches of engineering, I believe that the several professions would have been listed in this manner: (1) Electrical engineering; (2) mechanical; (3) civil, and (4)' mining. One in each hundred might have listed metallurgy as an engineering profession. Even the Society for the Promotion of Engineering Education in its Bulletin No. 10-"Investigation of Engineering Education" lists Civil, Mining, Mechanical, Electrical, and Chemical, leaving out Metallurgical Engineering.

Jan 1, 1930

By A. M. Gaudin, T. P. Meloy

This paper presents the theoretical derivation of the distribution equation for single fracture. The equation is shown to accord with experiment. Several empirical size-distribution equations have been proposed to describe the size of broken materials. Among them are the Gaudin-Schuhmann equation and the Rosin-Rammler equation.3*4 The Gaudin-Schuhmann equation relates the relative fraction of undersize to relative size —. In this relationship Mo is the total weight of crushed sample, M(x) the weight of undersize contained, x the size considered, K a quantity called the size modulus, which together with the slope parameter, m, characterizes the product. The slope parameter is usually close to unity. The Rosin-Rammler equation relates the same relative fraction of undersize to the relative size modulus by an equation of different form In this relationship, e is the base of natural logarithms. In the fine size-range when m is unity both equations give Gilvarry and Berstrom have sought a size distribution equation having a sound theoretical basis. They have come to an equation taking into account the effect of volume, surface and edge flaws in fragmentation. If the effect of the volume and surface flaws is neglected, the equation taking only edge flaws into account has the form of the Rosin-Rammler equation. In the present paper, a theoretical size-distribution

Jan 1, 1962

By Eric Jette

The nickel-chromium alloys form the base f for many industrial heating alloys, so that this system is of considerable practical importance. The literature on these alloys, however, contains much conflicting evi-dence, not only regarding the solubility limits of the terminal solid solu-tions at different temperatures but even regarding, the number of phases existing in the system. Part of the difficulty undoubtedly arises from the fact that chromium of sufficiently high purity has been available only during the last few years. A second and possibly even more impor-tant difficulty arises from the ease with which chromium reacts with silicon and carbon compounds and the atmosphere to form silicides, carbides, nitrides and oxides. Pilling and kihlgren1 in 1929 reviewed the existing scanty information. They did not consider the diagram by which they summarized the various bits of information to be entirely satisfactory. Matsunaga2 investigated the system by thermal analysis, microscopic examination and other means. Electrolytic nickel of 99.9 per cent purity and thermit chromium containing 0.30 per cent al, 0.40 per cent fe, 0.25 per cent si and 0.04 per cent c were used. A tammann furnace with hydrogen flowing through it was used for melting. Sekito and matsunaga3 reported an x-ray, investigation presumably on these same

Jan 1, 1934

By James A. Roberson

THE mechanical behavior of molybdenum has become a matter of considerable interest in recent years because it has a reasonably high strength at high temperatures. Various aspects of its fatigue behavior have been investigated previously,1-3 and the results can be summarized as follows. Recrys-tallized molybdenum exhibits a fatigue limit which decreases continuously with increasing temperature. The ratio of fatigue-limit stress to ultimate tensile stress is high (0.6 to 0.8) and reasonably constant. The present work was undertaken to determine the effect of variations in environment on the fatigue of molybdenum stressed in fully reversed axial tension compression. In order to provide a basis to which these data could be compared, a complementary series of fatigue tests were made in vacuum. All of the specimens used were made from one mill lot of unalloyed molybdenum which had been vacuum-arc melted, worked down to 1-in.-diam bar, re-crystallized, then warm-worked to 5/8 in. diam. The interstitial content by weight was as follows: C—0.022 pet, 02-0.0026 pet, Hz-0.0001 pet, and N20.0002 pct. The average grain diameter in the transverse direction was about 0.035 mm, and the average grain length was about 0.15 mm. Typical tensile-test data are shown in Table I. None of the specimens tested exhibited an upper yield point.

Jan 1, 1965

By H. K. Livingston

THE first person to investigate intensively the vast field of surface phenomena and capillary effects was the eminent English scientist, Lord Rayleigh (1842-1919), who laid down most of the fundamentals of this subject. This work was greatly amplified by Irving Langmuir,1 who, in connection with research for the General Electric Co., spent 25 years on the study of the surface chemistry of films, finally receiving the Nobel Prize in Chemistry for 1932 in recognition of his work. At present, William Harkins,2 of the University of Chicago, is the world's foremost authority on surface-tension measurement and his independent work, when combined with that of Langmuir, resulted in the orientation con-cept of solubility and surface activity, which is now an important funda-mental in chemistry. The theory laid down by these men was first applied to practical considerations regarding petroleum reservoirs by F. E. Bartell,3 of the University of Michigan, in connection with an American Petroleum Institute research grant. The latest and most advanced application of Bartell's work is contained in an article published in 1935 by Allen Garrison,4 of Rice Institute, in which he relates Bartell's measurements to the ratio of oil to water produced by wells and shows the types of petroleum reservoirs where the effects studied by Bartell are significant. This article is intended as a minor extension of such work.

Jan 1, 1938

By Edgar Kendall

A KNOWLEDGE of the fundamental principles of locating, sampling, testing and evaluating materials is essential in prospecting for mineral aggregates. In this discussion, mineral aggregates will be considered sand, gravel, crushed stone and slag that are used as materials of con-struction. The quantity of mineral aggregates produced in the United States during the year 1935 for such purposes was roughly 165,000,000 tons, about 60 per cent of which was sand and gravel, 37 per cent crushed stone and 3 per cent crushed slag. The total value of this material was approximately $100,000,000. It is apparent therefore that the prospect-ing for suitable mineral aggregates is of considerable economic importance. In prospecting for mineral aggregates, the methods employed are the same whether the organization is large or small. In the large organiza-tion there may be available geologists for locating sources of supply, a land acquisition department to arrange for the necessary options or permits, engineers to do the sampling, a laboratory for testing, and a board of consulting materials engineers to make the final selection. Even small organizations must follow the same general procedure, though the respon-sibility for the selection of aggregates may rest with one man, who may or may not be an engineer, but who must depend entirely upon his own judgment.

Jan 1, 1939