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By Gerald Sherman

(San Francisco Meeting, September, 1915) THE ore deposits of the Warren district, in which the mines of the Copper Queen Consolidated Mining Co. are situated, have been described in a number of technical publications, and will not be-discussed here in detail. Certain of their characteristics, however, control -methods of underground transportation and hoisting of ore. In the Copper Queen mine, the majority of the ore has occurred in a zone encircling the west boundary of the porphyry intrusion of Sacramento Hill. It has a width varying from 800 to 1,200 ft., and a thickness of about 400 ft. It reaches the surface in the older part of the mine to the northwest, but dips to the southeast, where it is reached at 1,400 ft. below the Czar collar, in its farthest extension at present developed on Copper Queen ground. There is one major extension from the northwest end of the zone toward the west along the Czar fault, and others of minor importance. Individual orebodies are scattered through the zone in an eccentric manner, only matched by their own irregularities of form and size. Their most general characteristics are the softness of the ore and their great horizontal rather than vertical extent. It has been estimated that the average vertical thickness of ore in the Czar and Lowell divisions is between 30 and 35 ft. It is calculated by assuming it to be uniformly distributed over its horizontally projected area. In this zone, and for some distance above it, the ground has been .subjected to intense alteration and intense but irregular oxidation. It has resulted in an enormous quantity of earthy or clayey material, which may be either ore or waste, which when wet is both heavy and tenacious. Below alteration, the ground is fairly hard, and the limestones contain primary ores differing from those heretofore considered typical of the camp, and which have not yet been thoroughly exploited. The mine production has been drawn from many orebodies spread . over a great area. A diagram map (Fig. 1), of haulage drifts and loading stations, illustrates the situation in 1914.

Jan 9, 1915

"The method of conveying ore from the ore-pocket at the shaft collar to the railroad ore bins, whence it is transported to the reduction works, is by cars with electric haulage.The cut shows the car coupled to the electric locomotive at the moment of dumping into the railroad ore bins.The locomotives used are of several makes, usually having two 12 ½ h-p. motors of a rated draw-bar pull of about 1,200 lbs., using 500 volts D. C. Track gauge is 30 inches, and speed is six miles per hour.The car holds two skip loads-10 tons—and has sides opening outwards the full length of the car, for rapid side-dumping. One man operates car and motor, and loads and unloads the car. The trolley pole runs in both directions without reversing.Loading is clone by operating a valve connected to a compressed air lift, which raises and lowers a gate in the ore-pocket chute, the ore running by gravity into the ore car spotted under the gate of the chute. Dogs hold the sides of the car in place at the bottom, the tops of the sides being hinged, and a hand lever releases the dogs, permitting the sides by the pressure of the ore against them to open at the bottom.With little manual effort one man does the work which was formerly done, when hoisting ore with cars and cage, by 10 men under laborious conditions."

Jan 1, 1913

Vol. 51 has been sent to all members who have paid their 1916 dues. Vols. 52 and 53, the last two volumes for 1916, will be shipped about the middle of-August to all except those owing current dues. Members who do not receive them within a reasonable time are asked to notify the Secretary. Back volumes to complete sets may be purchased from the Institute at reduced rates.

Jan 8, 1916

We regret to advise that, owing to unusual pressure of business at our printers, Volume TAX will not be ready for distribution so early as was announced in the last Bulletin. It will probably be distributed in November. Volumes LVII and LVIII were mailed during the month of August to all members whose dues were paid on Aug. 1; members who failed to receive their Transactions within a reasonable time are requested to notify the Secretary. In the case of members who have recently changed their addresses, the Transactions Were sent-to addresses on record on Aug. 19; those who did not notify .us of change of address until after Aug. 19 will find their Transactions at the old address.

Jan 10, 1918

Vol. 54 will be sent about February 1 to members who have paid their dues for the current year. Members who do not receive copies within a reasonable time are asked to notify the Secretary.

Jan 2, 1917

Vols. 52 and 53 have been shipped 60 all who have paid their dues for 1916. Members who do not receive them within a-reasonable time are asked to notify the Secretary.

Jan 10, 1916

Notice is hereby given that all members whose dues are paid for the year 1917 will be supplied with a copy of the Volumes MV and LV. Volume LVI has been delayed by the fact that our printer, like almost every other industrial society, has taken up war work and is under great pressure in addition thereto. Volume LVI will be sent before the end of the year, to members whose dues for the year 1917 are paid.

Jan 12, 1917

Volumes 57 and 58 of the Transactions were mailed together during the third week of August to all members whose dues for 1918 had been paid on Aug. 1. Any member whose copies fail to reach him within a reasonable time is requested to notify the Secretary. Volume 59 is on the press, and will be ready for distribution early in October.

Jan 9, 1918

Transactions of the Royal Canadian Institute, Vol. 12, Part 1, 1919, includes "The Reign of Law," by Dr. J. Murray Clark; "The Northern Interior of British Columbia and its Maps," by Rev. A. G. Morice, 0. M. I., M. A.; "Educational Reform: its Relation to a Solution of the Industrial Deadlock," by C. G. Corless, M. Sc. (McGill); "The Growth of the Scales on Fishes," by A. G. Huntsman, B. A., M. B.; "Intellectual Consequences of the War," by Franklin H. Giddings, Ph. D., LL. D., and "Industrial Research," by F.. B. Jewett, Ph. D."

Jan 7, 1919

Jan 1, 1959

Jan 1, 1958

The Institute's stock of Volumes XXXI, LI, and LII has become much reduced by sales: If members have copies of these volumes which they can spare, the price of $3 per volume will be paid for them, if in good condition. If desired, a copy of the Index for Volumes XXXVI to LV will he given for one of these volumes of the Transactions and one dollar additional. For two volumes of the Transactions, a copy of the Index will be sent and the balance will be credited to the payment of clues.

Jan 12, 1918

The Institute's stock of Volumes XXXI, LI, and LII has become much reduced by sales. If members have copies of these volumes which they can spare, the price of $3 per volume will he paid for them, if in good condition. If desired, a copy of the Index for Volumes XXXVI to LV will be given for one of these volumes of the Transactions and one dollar additional. For two volumes of the Transactions, a copy of the Index will he sent and the balance will be credited to the payment of dues.

Jan 1, 1919

By Leon Y. Sadler, E. K. Landis

Froth flotation has been described by several authors" as being analogous to a first-order rate process. Although a few investigators"," have found orders other than one fit their data best, the rate is described most often by the first-order equation, [ ] where r is rate of disappearance of floatable mineral by flotation, C(t) is concentration of floatable mineral in the cell, t is time, and k is first-order flotation rate constant. One of the difficulties in using this rate equation to develop a mathematical description of an actual flotation process is the determination of a suitable value of the constant k. The value of k, which reflects the floatability of the floatable mineral, is dependent on the hydrodynamic conditions in the cell, type and concentration of flotation reagents used, pulp density, and pH, method of froth removal, aeration rate, particle characteristics, and many other factors. Therefore, it is reasonable to expect that each particle of floatable material has a distinct value of k and that a unique distribution of k values exists for given feed and cell conditions. This has been observed and discussed by several investigators, and mathematical descriptions of the batch cell and steady-state continuous cell with distributed flotation rate constant have been developed." The mathematical description in the form of a transfer function of the continuous or flow cell under unsteady-state conditions with a distributed flotation rate constant has not been presented in the literature. The purpose of this note is to make such a presentation. The basic features of the perfectly mixed continuous

Jan 1, 1974

By Alexander R. Troiano, Taylor Lyman

Studies of the transformation of aus-tenite at constant subcritical temperatures have been numerous since the work of Davenport and Rain.' Considerable information has been obtained on low-alloy steels and on high-carbon alloys containing undissolved carbide or graphite at the austenitizing temperature. Little is known of the isothermal transformation of aus-tenite containing in solution large amounts of both carbon and a single alloying element. In this investigation four steels containing one per cent carbon and with chromium in the range 3 to 9 per cent have been examined with the view to establishing the fundamental character of the isothermal reactions when all carbon and chromium are initially in solution in austenite. Experimental Procedure Alloys The chemical compositions of the steels investigated are given in Table I. The 4 per cent Cr alloy is a commercial steel. The other steels were made by the Carpenter Steel Co. as 50-lb., induction-furnace heats and rolled to 5/8 -in. round bars. Bars were softened at 650' to 700°C. before the specimens were cut. Most of the lines on the transformation diagrams presented here have been placed on the basis of the microscopic examinatioll of partially reacted specimens, Thees specimens were approximately 1/2 by 1/4 by 1/8 in. ill size, specimens of the 9 per cent cr steel were held 10 to 12 hr, at 1200°to 1225°C. before quenching to the various subcritical temperatures. The other steels were held for 2 to 2 1/2 hr. at 12ooOC. before quenching. These treatments, carried out in an atmosphere of purified nitrogen, produced an austenite grain size larger than A.S.T.M. So. I, some grains being 1 to 2 mm. in diameter. There were a few undissolved carbide particles in some specimens of the 9 per cent Cr steel. It is believed, however, that any errors in the results due to incomplete solution of carbon and chromium in austenite are negligible; that is, austenite compositions may be considered as being those listed ill Table I. X-ray Methods Constituents were identified and mar-tensite axial ratios determined from Debye

Jan 1, 1945

By L. D. Jaffe, J. H. Hollomon

The effect of tempering temperature and time upon the properties of quenched steel is clearly a subject of great practical importance, as well as of considerable theoretical interest. It would be very desirable to be able to predict the properties of a quenched steel when given any selected tempering cycle, with a minimum of experimental work upon that heat or even type of steel. Two problems are involved: one consists of relating the structure obtained to the physical properties, and will not be discussed here; the other, with which this paper deals, involves the relations of time, temperature and composition with the structure obtained 011 tempering. Indentation hardness is perhaps the most convenient quantitative measure of the tempered structure, or of what might be called the "degree of tempering." Undoubtedly, it is not an exact measure, and in some cases (as when temper-brittleness occurs) pieces of the same quenched and tempered steel may have widely differing properties at the same hardness. However, hardness has the advantage of being simple to determine and is certainly the most widely used indication of the degree of tempering. Moreover, for fully quenched steels that are not temper-brittle and do not contain retained austenite when quenched, it appears that, in general, if the hardness of the steel is the same, the tensile and impact properties will also be identical, whether a high or a low tempering temperature is used. The tempering charts available in the metallurgical literature usually give the hardness as a function of tempering temperature for only one tempering time. However, in practice, tempering times frequently vary, and a method of converting tempering curves for one time to tempering curves for some other time would be very valuable. It is also advantageous, in determining the tempering treatment necessary for a given part, not to have to temper samples at several temperatures for the time used for the commercial tempering operation. A more satisfactory procedure would be to employ times of the order of 10 to 30 min., rather than 5 or 10 hr., and if possible to use only one temperature. Furthermore, it is frequently desirable, for reasons such as temper-brittleness,* to obtain a given hardness with short times at relatively high temperatures, and it would be convenient to be able to compute without tests the time required to produce this hardness. Remarkably few quantitative studies of the hardness of quenched steel tempered over wide ranges of temperature and time

Jan 1, 1945

By R. J. Marcotte, C. T. Eddy, R. J. Smith

The objectives of the investigation herein reported were to determine: (I) the S-curves for certain selected cast steels, (2) whether or not the published S-curves for wrought steels are satisfactory for use on cast steels of similar composition, and (3) to prepare hardenability curves of the selected cast steels. In order to make the final comparisons between cast and wrought steel more completely tangible, it was deemed advisable not only to determine S-curves for the steels submitted in the cast condition but also to roll some of the cast-steel test bars and determine comparison S-curves on such wrought material. This procedure eliminates the composition variable and makes it possible to reveal the differences resulting from plastic deformation of the cast structure in addition to providing the comparison with published data on wrought steels. Cast Steels The cast steels selected for the preparation of S-curves, or time-temperature transformation curves, were similar to S.A.E. series 1030, 2330, 4130 and 4330. Of these the 1030 was supplied by The Crucible Steel Casting Co., Cleveland, Ohio, and the other three by The Sawbrook Steel Castings Co., Lockland, Ohio. The steels were furnished in the as-cast condition. The manufacturers supplied the chemical analyses and the properties that could be obtained in the heat-treated condition—all of which is summarized in Table I. The metallographic and dilatometric procedures and equipment were in general standard. The specific technique employed was described in a report of the Steel

Jan 1, 1945

By E. P. Klier

The work of Klier and Lyman1 on the bainite reaction has led to the full description of this reaction for medium-carbon low-alloy steels. Certain experimental data reported by Klier and Lyman appear, however, to be improbable of obtaining in very high-carbon steels. The study herein reported consists of an analysis of the transformation characteristics of a 3 per cent chromium, I per cent carbon steel by means of X-ray and metallographic methods. From the results obtained it is concluded that the bainite reaction in this steel is more complicated than that reported by Klier and Lyman for the low-carbon low-alloy steels. Henever, the mechanism of bainite formation in this steel appears to be essentially the same as proposed for the low-carbon low-alloy steels with the modification that the first volumes to transform are carbon-rich rather than carbon-poor. Experimental Procedure The analysis of the steel studied was: Cr, 2.89; C, 1.02; Mn, 0.33; Si, o.35; S, 0.012; P, 0.020. The stock was received from the Carpenter Steel Co. in rolled bars. Specimen Preparation Specimens were austenitized at 1200°C. (2192°F.) for 25 min. in purified nitrogen. The resultant A.S.T.M. austenite grain size was 0-1. Isothermal transformation was allowed by quenching the specimens into liquid metal baths controlled to 5°C. at 540°C. (1004°F.) and above, and to 2°C. at 490°C. (914°f.) and below. Following the desired degree of transformation all specimens were water quenched. Metallographic Examination Specimens 1/4 in. round by 1/4 in. were used for nietallographic examination. Etch-ants used were Vilella's reagent (I gram picric acid, 10 ml. hydrochloric acid to make 100 ml. ethyl alcohol solution) and alkalinc sodium picratc (electrolytic). Vilella's reagent was effective in revealing all microconstitucnts, while the alkaline sodium picrate developed the carbon-rich structures or carbides only. X-ray Examination Two X-ray techniques were used—the Debye-Scherrer method and a back-reflection method. 'The small specimens necessary for the Debye-Scherrer method were austenitized and then allowed to transform, or were cut from the larger metallographic specimens. The metallographic specimens were used for the back-reflection X-ray analysis. When it was desirable to determine the structure of the carbide present, sliver specimens were electrolytically etched to develop a carbide coating, then were exposed in the cameras. This technique was frequently necessary to allow positive identification of the carbide.

Jan 1, 1945

By E. S. Davenport

WHEN annealed carbon, or low-alloy, steels are suitably heated the ferrite (alpha iron solid solution) and the carbide, of which they are composed, react together to form a single solid solution of carbon (and other elements) in gamma iron (austenite). This reaction may begin only at a certain minimum temperature called the eutectoid temperature. The first ferrite and carbide thus to react together do so in definite proportions known as the eutectoid composition. With further heating the original constituent that is present in excess is dissolved in the austenite until exhausted. Whether the excess constituent be ferrite (hypoeutectoid steels) or carbide (hypereutectoid steels) the procedure is much the same, and upon slow cooling the homogeneous austenite expels the excess of either (proeutectoid ferrite or carbide) until the eutectoid composition is reached. Thus the reaction upon heating is strictly reversed upon cooling and accordingly an equilibrium diagram of this process may be constructed. Such an equilibrium diagram concerns itself only with the tempera¬tures involved and with the proportions and compositions of the phases developed under conditions that suffice to permit equilibrium. Specifically it has no concern for the type or mode of distribution of these constituents nor with any extra-equilibrium conditions such as undercooling, which is almost universally encountered in metals. Actually, however, of great importance is the sluggishness toward equilibration caused by the not inconsiderable time involved in diffusion. Thus instead of the theoretical transformation point AE, we find for a certain rate of heating or cooling the use of the designations Ar and Ac (transformation temperature found on cooling and upon heating). These figures obviously have no particular meaning except as measured and expressed for a definite heating or cooling rate, and represent the apparent temperature displacement caused by an inadequate time allowance. In this paper are presented the results of a study of the time required for' the transformation of austenite to ferrite and carbide at a variety of temperatures and also of the time required for the reaction austenite ?martensite at the temperatures at which this reaction occurs instead of

Jan 1, 1930