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By J. B. Newsom

DURING July and August, 1931, the Bloomington Limestone Co.,. at Bloomington, Ind., ran a single wire saw on ledge No. 2 at Maple Hill quarry. The ledge was hard rock, much harder than the average Indiana limestone. It was opened at two ends for a depth of about 20 ft., leaving a 130-ft. section between. During the tests 21 cuts were made in this ledge, to an average depth of 10.42 ft., for a total effective cutting area 028,445 sq. ft. The actual area sawed was about 20 per cent higher, as we did not level down in the center, preferring to cut deeper on the ends. The various cuts were carefully, logged, and the results plotted. A study of these results is interesting, as it enables a forecast of probable future costs to be made, and also because it points out the limitations of wire saws, and the lines development should logically take. Some of the inferences to be drawn are discussed below. Best Length of Cut.-No. trouble was due to length of cut, except that we could not easily level down a long cut, and it is probable that longer cuts, say up to 200 f t., can be made. Obviously, longer cuts will result in a higher sawing rate, in square feet per hour if- they do not cause stoppages. Working Higher Ledges.-The cuts averaged 10.42 ft. high by 130 ft. long. A study of several logs indicated that during only about 15 per cent of the cutting time was the saw cutting to its full efficiency; that is, during about 85 per cent of the time the saw was bedding in at the ends and not cutting well in the center, or the ends were below the floor line and only part of the wire was doing effective cutting. This does not mean that the wire was cutting to only 15 per cent of its capacity, but it means that during about 85 per cent of the time part of the cutting was being wasted. If higher ledges had been worked, the wire would have cut to its full efficiency a large part of the time, as it would have had a greater distance; to saw after it had bedded in to the ledge before the ends went down below the floor level. The exact saving to be expected cannot be calcu-lated, but it would be large, if really high cuts were made.

Jan 1, 1932

By Wolfgang Pitsch

INVESTIGATIONS on the above topic have recently been published by Shapiro and Kraussl and Jana and wayman in this journal and by Kessler and Pitsch.- Parts of the results in these papers are in good agreement with each other but there are also some results which are substantially different. The main points of these differences shall be briefly discussed in this communication. Shapiro and Krauss' measured single-surface traces of the habit planes of reversed austenite plates formed within the martensite crystals and deduced from these measurements two distinct habit planes A = (0.174; 0.309; 0.935) and B = (0.375; 0.545; 0.749) within 3 deg. Kessler and pitsch4 found instead by two-surface analysis7 one habit plane n = {0.23; 0.62: 0.75) with a real scatter of 6 deg. The latter observation of a single habit plane apart from a certain scatter is in agreement with most of the investigations of martensite transformations. The differences between these two results are so great that they cannot be explained by experimental error. The purpose of this communication is to show that the A- and B-poles of Shapiro and Krauss are due to an erroneous interpretation of a single-surface trace analysis. The difficulties in the interpretation of such single-surface trace analyses are due to the high symmetry of cubic lattices, from which it follows that there are in general twenty-four equivalent possibilities of plotting a single-surface trace in a pole figure. All these possibilities must be taken into account, when putting different traces from different plates together in order to construct the habit plane. Alternatively the poles of all the traces may be plotted in a unit triangle. This is done in Fig. 1 with twenty-nine traces of different reversed austenite plates, all of this were measured by Shapiro and Krauss in the same plane of a single martensite ther traces taken from Fig. 13 in the Shapiro and Krauss paper' which were determined by electron diffraction. The traces in Figs. 1 and 2 have to be compared with the habits A, B, and n which are under discussion. Therefore the great circles of the poles A, B, and n are plotted in Figs. 3, 4, and 5 together with a 3-deg scatter region for poles A, B and a 6-deg scatter region for pole n. Comparing Figs. 1 and 2 with Figs. 3, 4, and 5 one finds the statements which

Jan 1, 1969

The Pinson Mining Co., which will start production in very early 1981, is the fourth Carbon-In-Pulp plant to be put into operation in the United States. The property is located in Humbolt County, Nevada, 38 km (24 miles) northeast of the town of Golconda. The famous Getchell Mine was also near Golconda and was the site of one of the early Carbon-In-Pulp plants in the 1940s. The deposit was discovered in 1971 by Reno based Cordilleran Explorations, which is founded by a consortium of Canadian mining companies. Cordilleran is a partnership consisting of John Livermore and Peter Galli. In 1972 a second but smaller deposit, called "Preble", was discovered at a location 15 miles south of Pinson. During 1980, a decision was made to place the Pinson deposit into production and Pinson Mining Company was formed. Ownership of Pinson is vested in Lacana Mining Inc. , Rayrock Mines, Inc. , Siscoe Metals, Inc., John S. Livermore, Peter E. Galli and Donald M. Duncan. Three distinct but connected ore zones occur at Pinson. Combined reserves of milling ore total 3, 200, 000 tons at an average (undiluted) grade of 4. 12 g per mt (0. 12 oz per st) Au. Initial mining will be from "A" zone which contains 1, 500, 000 tons with an average (undiluted) grade of 5. 8 g per mt (0. 17 oz per st) Au. An additional 5, 500, 000 tons of low grade ore will be mined from the Pinson deposit and processed by heap leaching. Mining reserves at Preble total at least 1, 500, 000 tons grading 2. 7 g per mt (0. 08 oz per st) Au. Production plans for the Preble deposit have not been formulated at the date of writing. Gold mineralization at both deposits is finely disseminated as sub micron sized particles. The ore at Pinson is structurally controlled and occurs in an Ordovician limestone-siltstone unit. Much of the ore has been silicified to a jasperoid. The ore zones have been entirely oxidized. Preble ore occurs in the Cambrian formation in a carbonaceous, limey shale. Only the upper part of the Preble is oxidized and amenable to conventional cyanide leaching. The Pinson ore body is adjacent to the mouth of Granite Creek in the Osgood Mountains at an elevation of 1, 615 m (5, 300 ft) with the mill being 1. 2 km (3/4 mile) from the mine at an elevation of 1, 495 m (4, 900 ft). Mine development work began in May of 1980 with ore being stockpiled for later processing. Pertinent factors affecting

Jan 1, 1981

By C. E. Arnold

In attacking the problems of mining and treating large disseminated copper orebodies such as those occurring in the Miami or the Ray district of Arizona, one of the vital questions to be decided is, "What is the value of the orebody per ton in place?" The importance of this question lies in the fact that its answer helps to reach a decision concerning the method of mining to be employed. Let it be assumed for the moment that milling and smelting practice, especially the latter, is more or less standardized, and has a cost incapable of much variation, while the cost of mining has a considerable range owing to the large number of mining methods by which a mine may be exploited. For instance, a method may be adopted whereby all the available ore can be extracted perfectly clean (i.e., unmixed with barren material) at a relatively high cost; or a method may be used involving the necessary dilution of a portion of the ore with waste, in order to recover that portion, thus giving a relatively poorer extraction but nevertheless a lower working cost than the former method. Naturally, between these two extremes there lie intermediate methods. In order to arrive at a solution of a mining method problem that is of any value, it is necessary that accurate and complete estimates of mining, milling, and smelting performances and costs shall be established. By way of illustration is given a case of mining, by the system of undercutting and caving, a large orebody with an average content of 1.50 per cent. copper supposedly all in sulphide form, to which case has been applied those results in mining operations which one may fairly assume are to be expected when viewed in the light of G. R. Lehman's ore-drawing experiments, which form the subject of a paper to be presented at this meeting. It is assumed that the total costs will be as shown in the table on page 204. To attain these costs, a daily production and treatment of 14,400 tons has been assumed. Other assumptions are as follows: 15 per cent. of orebody is to be extracted clean by development work and undercutting; 63.8 per cent. (75 per cent. of 85 per cent.) is to be extracted clean by caving, leaving 21.2 per cent. part of which is to be extracted by diluting with waste, and the remainder lost. Dilution and extraction are to

Jan 1, 1917

By Clarence Zener

The internal friction of nonferrous metals vibrating at low stress amplitudes has so far always been successfully interpreted in terms of inhomogeneities of one sort or another. Examples are the fluctuation of stress across a specimen vibrating transversely,1,2,3 the stress inhomogeneities due to the elastic anisotropy and partial random orientation of the individual crystallites, localized weak regions introduced by cold-working,6'7 grain boundaries and possibly twinning planes.8'9 Perfect single crystals are, by definition, homogeneous. Actual single crystals usually, perhaps always, contains some imperfections. The present investigation was undertaken to determine whether the internal friction of single crystals may likewise be attributed to inhomogeneities. This study was made possible through the gift of a large single crystal of 70-30 alpha brass by H. L. Burghoff, of the Chase Brass and Copper Co. The specimen, 3.i in. in diameter and 10 in. long, was similar to samples previously described by Mr. Burghoff. Experimental Method The experimental method used has previously been described in institute papers.5'6'9 The measure of internal friction adopted here, I/Q, is X the logarithmic decre- ment, a measure used by some writers, and is also X the specific damping capacity, a measure used by other writers. In all measurements the stress level was kept so low that the measurements were independent of stress level. In all measurements in which the temperature was varied, observations were made as the specimen slowly cooled from its highest temperature. The specimen was vibrated transversely. Observations were made at the fundamental frequency and at the first overtone, of about 620 and 1710 cycles per second, respectively. No attempt was made to avoid acoustical losses. Experimental Results The specimen was annealed for several hours at 450°C. The temperature dependence of the internal friction was then determined from room temperature to 400°C. As shown in Fig. I, the internal friction increased by only a factor of 2 from room temperature to 300°C., then by a factor of 100 during the next Ioo° interval. These measurements are consistent with the view that the observed internal friction is the superposition of two distinct parts. One, dominant at room temperature, is nearly independent of temperature. This part may be accounted for by acoustical losses and by transverse thermal currents. It was not further investigated. The second part, when plotted in the manner of Fig. I, lies upon a straight line. Therefore it has a heat of activation H; i.e., it varies with temperature as Internal friction e-H/RT [I]

Jan 1, 1943

SMALL things are customarily moulded in two ways (unless they have undercut parts which hold them in the moulds); that is in clay, or with natural or which artificial earthern powder made in halves in either wooden boxes or bronze frames. This also depends on whether the object is larger or smaller. Now if you wish to mould with moist clay, you must grease your relief with oil or pig fat; apply a dusting of charcoal, ashes, or cuttlebone on it; or gild or silver it dry with gold, silver, or tin foil. Then, first make with moist and somewhat firm clay a plate as, thick and large as can conveniently hold your relief, and carefully set the latter halfway into this and let it dry. Then, greasing or dusting it again, make the other half. When both are well dried, take out your relief and at the top make its gates and vents. If plastering is needed, do it. Finally, bake the halves, fit them together, and tie them well, as you wish, using the procedure that I taught you in the discussion of brass. But if one has to make a large quantity of works of one kind, he should for the sake of convenience use the method with powder [120] because it is short and requires less time and expense. Therefore if you wish to do this, you need to have several pairs of bronze frames or wooden boxes, higher than half the relief that you wish to mould, and of convenient length. On a flat board always keep half of one of these frames full of powder that has been slightly moistened for moulding, as I told you, so that by pressing with the ends of the fingers and with the hand it holds together as well as possible. Level it off with a cutting tool and when leveled put a flat board over it and turn it over. Turn it on to a dusting of ashes so that it will not stick, dust it on the other side, and remove the excess by blowing it off Then mould the thing that you wish to mould, pressing it halfway in once or twice, always taking it out and putting it back again. Then the other frame is fitted in its place and filled with earth by pressing and squeezing it carefully. Then it is leveled off on the outside with a sharp tool as you did with the other part, and then one of the parts of the frames is lifted up with the point of a knife or some other tool and,

Jan 1, 1942

HAVING demonstrated to you above the practice of bringing silver to its ultimate fineness and perfection, it now remains for me to describe how the two kinds of metals that are found in the smelting product that you made from the ores are to be brought to their end: One is copper and the other lead, and perhaps a third is gold, if per-chance the silver that you refined in the cupeling hearth contained any. It would be almost impossible that it should not contain any, because either a little or a lot is almost always found as an admixed substance not only in silver but in. every one of the other metals as well. But in order to continue in sequence, you must suppose that there is some gold and that, of the two materials you have that I mentioned above and told you to save, one is the matte (calling it according to the usage of Germany, * since I do not know a more exact or better word for describing it to you) and the .other is the litharge that you took from the cupeling hearth. In addition, the hearths themselves are saturated and full of lead. If these things should remain in their present condition they would be useless bodies without any perfection. First, taking one of the three said parts, as a material of greater quantity and also as a thing that needs greater labor, and because, being reduced to the point I have told you with smelting and evaporation, it is nearer to its end, I shall tell you what must be done in order to bring it to pure copper. As I have told you, there are two materials on hand, one of which is the matte and the other the litharge. Each at first sight seems a half-burned thing; one has already been finished metal and the other is to be, but in my opinion the matte is nearer to its end than is the litharge because the latter has been dried by the power of the fire and re-formed from another body. Now leaving aside the discussion of this thing, after the matte has been well evaporated and reduced, it is taken and put on a forge. In front of the tuyère a receptacle is made of stones that neither calcine nor melt, or of coals and powdered clay, in the form of a little cradle that is longer than it is wide and not very deep. Its length should be about one and a half

Jan 1, 1942

THERE are, as I have heard, varying opinions among men experienced in minerals as to whether silver has its own mineral [i.e., occurs native] or not. Mineralogical reasons and the authority of the majority persuade me that it has, not only because I have seen the natural material separate but also because I know that in mines of gold, copper, lead, and other metals pieces of pure metal are found without admixture, and I have heard that pieces of silver, gold, and copper have been found that had been reduced to their ultimate purity by natural causes. This is also confirmed by a German, Georgius Agricola, who says* that in a mine in Saxony a piece of metallic silver was found so large that the Duke who was prince and patron of the place had a whole dining table of square German style made from it without its being enlarged or worked on by any human artifice except for the tripod legs, and he often boasted that in this he surpassed the greatness of the Emperor. In truth I have never seen any metal except copper that was brought out from the mine pure and without any mineral, but I think that such a thing is indeed possible, since I believe in the greatness and power of Nature, who strives toward no other goal than perfection and purity. Indeed most of the minerals that I have seen have not been without admixture, not only of their earth but also of other metals, and this is more true of that which I have heard called silver than of any of the others. I except the silver that is mined in Schio in the region of Vicenza. These doubts, therefore, are not born without some shadow of apparent reason. As I told you above I believe that silver may have and does have its own mineral, for every substance that is converted into metal can exist pure by itself in its own species, as it also exists separately even though it be mixed with others, since it is seen that in each ore its metal is generated in a single body. Therefore it happens many times that whoever speaks of the ore of silver in one breath, without distinction, speaks of that of all the other metals, because there are few ores that are not mixed. But because the most noble things always have the prerogative of including in their name that of the others, where there is gold or silver the ores are not called

Jan 1, 1942

Anders Richard Akerman entered the eternal rest on Feb. 23, 1922, after a long and distinguished career. All mining men in Sweden arc mourning him, because he was one of their greatest and a leader in the scientific metallurgy of the iron. He was born April 18, 1837, in Stockholm, where his father, Joachim Akerman, was a professor at the Technical University, but the greater part of his childhood was spent in Falun, where the family moved after his father was made principal of the mining academy. He was at first taught by a tutor, but in 1851 entered the high school in Vesteras and the University of Uppsala in 1855, from which he graduated as a mining engineer on Dec. 11, 1860. A week later, he entered the service of the Department of Commerce and entered the mining academy at Falun, from which he graduated Dec. 15, 1862. The following May, he was accepted as a student in the metallurgical section of "Jernkontoret" (the "Iron Institute") and on Oct. 22, 1864, he was made an assistant in the same section. Thus begun the cooperation with the Iron Institute which was to continue for so many years and to bear such rich fruit. He had, however, previously received two requests from the Iron Institute: One to assist Prof. V. Eggertz in the preliminary work of preparing a handbook on blast-furnace practice, the other to make a complete index of the proceedings of the Iron Institute ("Jernkontorets Annaler") volumes 1817-1864, which index was published in 1866. On Oct. 19, 1865, Akerman was requested by "Jernkontoret" to give during 1866, lectures in the metallurgy of iron at the mining academy of Falun, as Prof. V. Eggertz wished to devote his entire time to the study of assaying. This request was renewed Oct. 15, 1867, for the year 1868, and on April 17, 1869, he was made instructor in metallurgy and mining at the Technical University, to which institution the higher education in mining engineering was transferred at that time. Akerman thus entered his career as a teacher, which lasted until the end of 1891. On May 11, 1877, he was appointed assistant professor in metallurgy and mining; on Sept. 7, 1883, he was appointed acting professor in the same department; and two weeks later was appointed dean of the mining college. On May 21, 1874, he was instructed by the Crown to inspect the mining schools in Filipstad and Falun. As a teacher, Akerman was very popular and his lectures were excellent, in form as well

Jan 1, 1922

By James Norman, O. C. Ralston, John Dasher

MOST mineral products are used in the finely divided state, but some are sold in larger sizes. Coal, gravel, metallurgical fluorspar, phosphate rock, hematite, chromite, and other products are sold in sizes coarser than can be treated by many mineral-dressing methods. Gravity separation of coarser sizes by log washing and jigging is probably as ancient as any process now in use. The performance of jigs on a feed with sufficient difference in density of the minerals is excellent, but many families of minerals are too similar in density to be separated effectively by this method. The use of heavy suspensions of fine solids to separate coarse coal from bone and slate has been in use for some years. This separation by sink-and-float was limited until recently to light minerals. Development of galena and ferrosilicon as suspension media, by Minerals Beneficiation, Inc., at Mascot, Tenn., Pitcher, Okla., and Crosby, Minn., under patents granted during and since 1938, has permitted excellent results to be obtained on minerals of very similar densities up to 3.3. This process has been put in the hands of American Cyanamid Co. for exploitation, and further research now in progress may increase the density of suspension obtainable so that separation, at a density of 4,0 may be practicable before this is published. The Huntington-Heberlein dense-medium process, developed in England, is also being commercialized in the United States by Sink and Float Corporation. Du Pont has developed a sink-and-float separation using halogenated hydrocarbons as parting liquids; at this writing, the method is used commercially only on coal but has been successful in the pilot plant on many other minerals using tetrabromethane at densities up to 2.95. While these processes were being developed to extend the range of separation by difference in density to the coarser sizes, the Bureau of Mines was engaged in developing a process that will extend the range of separation by difference in wettability up to 2-in, size. War work has pushed aside its further development indefinitely. The results are published here with the hope that some use may be suggested that will justify post-war development, and so that readers that may be able to make immediate use of the scheme may have the information. EARLIER WORK It has been known since the time of Herodotus (B.C. 484(?)-425) that water-repellent particles will adhere to sticky surfaces. That early historian reports the

Jan 1, 1942

By M. G. Cheney

THE production record of the Sinclair-Moren pool, in southeast Young County, Texas, demonstrates that under efficient operating methods a single well may obtain normal oil recovery from an area of 100 acres or more. This record is the more surprising in view of relatively adverse reservoir conditions such as lack of water drive, moderate initial reservoir pressures and a consolidated sandstone reservoir with original permeability greatly reduced by processes of lithification. This case history is considered worthy of special study in view of the ever present problem of proper spacing of wells. Cupidity, abetted by the unrestrained law of capture, has in too many instances guided development and production methods without regard for sound economic and engineering principles. Largely as a result of ill advised spacing of wells, many oil fields have brought financial losses instead of deserved profit to those using capital, time and energy in this important business of adequately meeting the petroleum requirements of what is known as our modern civilization. In March 1923, the Sinclair Oil and Gas Co. obtained initial daily production of about 12,000,000 cu. ft. of gas and 1100 bbl. of oil in its first well near the center of a 372-acre lease on the L. P. Moren land, James Rose survey, Abstract 245. This exploratory test was drilled as a geological prospect of average promise, on a plunging anticline with possibly 10 ft. of closure as mapped on the outcropping limestone of upper Canyon (Pennsylvanian) age. In subsurface, the top of the producing res-ervoir is 16 ft. lower in this well than in the highest wells but probably 25 ft. above lowest closing contour. Wells No. 2 and 3 were drilled about 1/4 mile west and southwest near a normal fault with some 30 ft. of downthrow to the southwest. The producing sand was reached at a depth of 2512 ft. and drilled to 2529 ft. in the first well. This sandstone reservoir is of Millsap Lake (middle Strawn, upper Cherokee) age. It was absent in the second and third wells, which were abandoned at the depths of 3725 or more. In April 1925, a fourth well was drilled 600 ft. east and 24 ft. lower for top of sand than No. I. Production of about 100 bbl. daily was reported from 2521 to 2562 after an 80-quart shot. This well was drilled to 4560 ft., plugged back to 2575 and shot again; but was abandoned soon thereafter because of small production.

Jan 1, 1940

Discussion of the paper of Dorsey A. Lyon and Robert M. Keeney, presented at the Butte meeting, August, 1913, and printed in Bulletin No. 80, August, 1913, pp. 2117 to 2149. C. D. WOODWARD, Butte, Mont.:-We constructed a small blast furnace, and used first carbon electrodes and an alternating current of about 50 to 75 volts. We were able to smelt the material which was fed to the furnace, but we did not carry on experiments far enough to see just exactly what the power consumption was and compare it with the amount of material treated. We found that the blast seemed to help materially in reducing our charge and cutting down our power consumption. There were several other experiments tried at the time, and I do not call to mind now just what they were. We were trying to do away with the carbon electrode and replace it with an iron one, and it also seems to me we tried to use the ore for an electrode; but I believe that the electric furnace in the reducing end is simply a question of British thermal units per kilowatt-hour compared with British thermal units in a pound of coke. Now, if a pound of coke costs us 0.5 c. and a kilowatt-hour costs us in the neighborhood of 1.5 c., I think there is a big advantage in using coke instead of the electrical current for copper reducing. We tried steam, and a number of other methods, to throw copper down, but it has been some time ago and I am not very familiar with them now. The outlook of the experiments did not seem to be very promising, and we took it more as a thermal problem than an electrical one. PROF. JOSEPH W. RICHARDS, South Bethlehem, Pa.:-Mr. Woodward has spoken of the question as a thermal problem. I would call attention to the fact that electric furnaces usually utilize the heat of the electric current at from four to ten times the efficiency with which the heat generated by fuel is utilized; so it will not do simply to compare by thermal units generated. Your total thermal units may cost much less from coke than from electricity, yet you will find the electrically generated thermal units utilized in a properly designed furnace from three to ten times more efficiently than in the combustion furnace. You must make that allowance is comparing the cost of thermal units generated electrically and thermal units from coke.

Jan 11, 1913

department, first as a practical miner, next. as rodman on the survey corps, of which he soon became chief, then draftsman and mining engineer in the company's office. In January, 1916, he was promoted to the position of district engineer in charge of mining engineering work. He became a member of this Institute in September, 1917. Captain Ba.llamy's military experience began at the same time as his engineering practice. He was a charter member of Company A, Engineers, N. G. P., which was organized ten years ago. He saw service on the Mexican border as First Lieutenant of this Company, and remained in that position until November, 1916. In July, 1917, he was again called into service and was sent to Camp Hancock, Ga., with the 103d Regiment of Engineers. Before joining this regiment he attended a school for officers at Fort Sill, Okla., where he received special training in field fortifications. In December, 1917, he was commissioned Topographical Captain on the Regimental Staff, and in April, 1918, preceded his regiment by about six weeks to France, where he again attended an officers' training school. He rejoined his regiment on July 15, near Chateau Thierry and was killed near Fismes on Aug. 9, 1918. Lieutenant Martin F. Bowles Martin F. BOWleS, born Apr. 25, 1893, at Bonne Terre, Mo., and graduated from the Neodesha, Kans., High School, had finished all but one month of a four-year course in metallurgical engineering at the Missouri School of Mines, Rolla, Mo., when on May 12, 1917, he entered the first Officers' Training Camp at Fort Riley, Kans. At the close of the training period, he was commissioned a Sccond Lieutenant and assigned to Co. B, 355th Infantry, 89th Division, and stationed at Camp Funston. He left this camp with his company on May 21, 1918, and sailed from an eastern port on June 4, ayriving in England on June 15, 1918. After a short stay at a rest camp there, he proceeded to France. On August 14, he wrote that he was with Battalion Headquarters as Gout Officer, 1st Battalion, 355th Infantry, 89th Division. The last letter received from him, dated September 2, was written in his dugout and contained the following: "Here it is 2.45 a. M. Sitting in a dugout waiting for some patrols to report back in, I am writing this by the light of two candles." He was killed in action on the night of Sept. 3, 1918. The letter of notifi-

Jan 1, 1920

By Klaus Schwerdtfeger, Leo Zwell

The equilibrium between Ir-Fe or Rh-Fe alloys, iron oxide (wüstite or magnetite), and CO2-CO atmospheres has been determined at 1200°C. The data are used to derive the activities in these binary solid solutions. Both systems show negative deviations from Raoult's law. The lattice parameters are given for the investigated Ir-Fe and Rh-Fe alloys. IRIDIUM and iron form a continuous series of fcc solid solutions at elevated temperatures.' Rhodium-rich Rh- Fe alloys have fcc structure.' In the medium concentration range an ordered bcc phase is stable at temperatures up to about 1300°C. Phase relations in iron-rich alloys are not well-known. No thermody-namic data are available for these alloys. EXPERIMENTAL METHOD The experimental method used was to measure the equilibria between a gas phase of known CO2/C0 ratio, the alloy, and iron oxide (wüstite or magnetite). In one series of experiments the alloys of known composition were heated in CO 2-CO gas mixtures. After treatment (usually 1 day) the sample was quenched to room temperature and its surface examined visually to determine whether an oxide tarnish had formed. The procedure was repeated at slightly higher CO 2/CO ratios until the CO 2/CO ratio of incipient oxidation was found. Subsequently, the CO 2/C0 ratio was lowered again in small increments until the tarnish was reduced. In other experiments mixtures of alloy and iron oxide powders were pressed into pellets and equilibrated with the CO2-CO gas phase. In order to ensure that equilibrium was attained, two specimens with different starting iron content were heated side by side; in most cases, equilibrium was approached in one pellet by reduction of iron oxide and in the other pellet by oxidation of metallic iron. The sample was quenched to room temperature, and the composition of the equilibrated alloy was determined by X-ray measurements of lattice parameters and comparison of these values with calibration curves obtained from alloys of known composition. The oxides present in the specimens were identified by comparison of their diffraction patterns with those in the ASTM Card File. It may be expected from the noble character of iridium and rhodium that no appreciable amount of iridium or rhodium is dissolved in wiistite and magnetite under the present experimental conditions. The activity of iron in the alloy is then equal to that established in the iron oxide by the COrCO atmosphere. The activities of iron in wüstite and magnetite, as a function of oxygen pressure, were taken from the work of Darken and Gurry,

Jan 1, 1969

I HAVE now traversed for you in the small and fragile bark of my writing all the shores of the deep and spacious sea embracing the uses of material fires, drawn on by my own desire to enrich you with more learning and with the procedures of these things, as much as to satisfy your demands. Having through the grace of God arrived at the appointed end of my voyage and neither knowing nor perceiving a way of going farther, I had decided to furl the [167] sails and cast die heavy anchors into the water in order to enjoy in tranquillity respite from my sailing, when I was warned by my pilot that before I could disembark I should turn my glance backward and reexamine my work in detail to see if there were any part that had by chance remained undescribed in the obscurity of silence. When I did this there immediately appeared in my mind's eye the many sublimates and smoky tinctures that had been made by the burning and most powerful fire of love. I need not say that I knew of it in far-off countries or from the knowledge of others, but I knew it in my own breast and as my very own and can therefore surely esteem it as hotter than all the other fires that the world calls by that name. Although today its sparks and living flames are spent because of my cold and hoary season, nevertheless it is true that the memory of acts of love of long ago still remains with some smoke and warmth. Therefore, since in this work of mine I wish to describe for you the effects and powers of fires, I should logically have spoken of this before any of the others, because of its actual nearness and the great acquaintance I had with it. But since I have had the glance of my intentions directed at distant things, I have behaved as one does who does not see where he places his feet because he is looking at the sky, or as one who thinks about the affairs of others and forgets his own. But now I do not wish to pass over this thing and I wish to correct my error, particularly in order to provide a happier ending to my written work than by remaining among the horrible uproar of guns, powder, and saltpeter, which would be a harsher ending than speaking of love. Never-

Jan 1, 1942

By Clarence Zener

IT has long been known that the density of a metal usually decreases with cold-work. Thus O'Neill1 observed as early as 1861 that cold hammering of commercial hot-rolled copper is accompanied by a decrease of density of 0.2 per cent, and that subsequent annealing restores the original density. The origin of this density change, however, has remained obscure. In particular, experiment has not yet decided whether it is due to the presence of small cavities and an increase in intergranular surface or to an actual expansion of the lattice itself. This uncertainty in the origin of the change in density is a reflection of our uncertainty as to the changes induced in a metal by cold-working. One school regards cold-working as a breaking up of the original grains into a large number of perfect crystallites somewhat randomly orientated with respect to one another.2 According to this viewpoint, the mere introduction of a large intercrystallite surface induces a net volume expansion. Another school regards cold-working primarily as a distortion of the grains. It is not obvious that this second viewpoint will lead to a net volume expansion. The purpose of the present paper is to show that this is indeed the case, and that this expansion is of the right order of magnitude to explain existing experimental data. The physical basis for the association of an expansion with distortion lies essentially in the variation of the elastic moduli with volume. This variation is considerable. Thus from Table I we see that a I per cent increase in volume for the case of copper will decrease the bulk modulus K by i0 per cent, the shearing modulus µ by 3.8 per cent. If we thus twist a rod through a given angle, we shall do less work upon it if it increases slightly in volume, thereby reducing the torsion modulus that involves as a factor the shearing modulus. A general principle' in physics states that the rod will so adjust itself as to have a minimum potential energy consistent with the end restraints. It will therefore expand. [ ] In order to obtain a quantitative comparison with experiment, we follow Maier4 in comparing the lattice expansion with the latent energy of cold-work. This latent energy has been measured directly by Taylor and Quinney5 on copper rods subjected to torsion, and may amount to as much as 15 per cent of the total work done upon the specimens. We shall assume that this

Jan 1, 1941

By James Norman, O. C. Ralston, John Dasher

Most mineral products are used in the finely divided state, but some are sold in larger sizes. Coal, gravel, metallurgical fluorspar, phosphate rock, hematite, chro-mite, and other products are sold in sizes coarser than can be treated by many mineral-dressing methods. Gravity separation of coarser sizes by log washing and jigging is probably as ancient as any process now in use. The performance of jigs on a feed with sufficient difference in density of the minerals is excellent, but many families of minerals are too similar in density to be separated effectively by this method. The use of heavy suspensions of fine solids to separate coarse coal from bone and slate has been in use for some years. This separation by sink-and-float was limited until recently to light minerals. Development of galena and ferrosilicon as suspension media, by Minerals Beneficia-tion, Inc., at Mascot, Tenn., Pitcher, Okla., and Crosby, Minn., under patents granted during and since 1938, has permitted excellent results to be obtained on minerals of very similar densities up to 3.3. This process has been put In the hands of American Cyanamid Co. for exploitation, and further research now in progress may increase the density of suspension obtainable so that separations at a density of 4.0 may be practicable before this is published. The Huntington-Heberlein dense-medium process, developed in England, is also being commercialized in the United States by Sink and Float Corporation. Du Pont has developed a sink-and-float separation using halogenated hydrocarbons as parting liquids; at this writing, the method is used commercially only on coal but has been successful in the pilot plant on many other minerals using tetrabrom-ethane at densities up to 2.95. While these processes were being developed to extend the range of separation by difference in density to the coarser sizes, the Bureau of Mines was engaged in developing a process that will extend the range of separation by difference in wettability up to 2-in. size. War work has pushed aside its further development indefinitely. The results are published here with the hope that some use may be suggested that will justify post-war development, and so that readers that may be able to make immediate use of the scheme may have the information. Earlier Work It has been known since the time of Herodotus (B.C. 484(?)-425) that water-repellent particles will adhere to sticky surfaces. That early historian reports the recovery of gold from the mud of a lake

Jan 1, 1943

By James Norman, O. C. Ralston, John Dasher

MOST mineral products are used in the finely divided state, but some are sold in larger sizes. Coal, gravel, metallurgical fluorspar, phosphate rock, hematite, chromite, and other products are sold in sizes coarser than can be treated by many mineral-dressing methods. Gravity separation of coarser sizes by log washing and jigging is probably as ancient as any process now in use. The performance of jigs on a feed with sufficient difference in density of the minerals is excellent, but many families of minerals are too similar in density to be separated effectively by this method. The use of heavy suspensions of fine solids to separate coarse coal from bone and slate has been in use for some years. This separation by sink-and-float was limited until recently to light minerals. Development of galena and ferrosilicon as suspension media, by Minerals Beneficiation, Inc., at Mascot, Tenn., Pitcher, Okla., and Crosby, Minn., under patents granted during and since 1938, has permitted excellent results to be obtained on minerals of very similar densities up to 3.3. This process has been put in the hands of American Cyanamid Co. for exploitation, and further research now in progress may increase the density of suspension obtainable so that separations at a density of 4.0 may be practicable before this is published. The Huntington-Heberlein dense-medium process, developed in England, is also being commercialized in the United States by Sink and Float Corporation. Du Pont has developed a sink-and-float separation using halogenated hydrocarbons as parting liquids; at this writing, the method is used commercially only on coal but has been successful in the pilot plant on many other minerals using tetrabromethane at densities up to 2.95. While these processes were being developed to extend the range of separation by difference in density to the coarser sizes, the Bureau of Mines was engaged in developing a process that will extend the range of separation by difference in wettability up to 2-in. size. War work has pushed aside its further development indefinitely. The results are published here with the hope that some use may be suggested that will justify post-war development, and so that readers that may be able to make immediate use of the scheme may have the information. EARLIER WORK It has been known since the time of Herodotus (B.C. 484(?)-425) that water-repellent particles will adhere to sticky surfaces. That early historian reports the

Jan 1, 1942

By Oscar T. Marzke

Four alloys that precipitate the alpha phase from the beta of the copper-zinc system were heat-treated in various ways to develop as many forms of the segregate as possible. It was found that the precipitate may have the form either of plates or of needles. Plates usually result when precipitation occurs at low temperatures and needles when precipitation takes place at high temperatures. The needles tend to align themselves along certain planes in the matrix and to coalesce into plnte-like structures. The two phases were found to be related so that a (111) plane and [Oil] direction of the precipitate are parallel to a 10111 plane and 11111 direction of the matrix. DISCUSSION (E. A. Anderson presiding) D. W. Smith, Pittsburgh, Pa. (Written discussion).—Tllis report by Dr. Marzke covers completely all possible heat treatinents over a considerable range of compositiol~s in which a1pha precipitates from beta brass, and may be said to complete the Inctallographic part of this problern The lining up of ncedles of segregate to form plates, espeeially as shown in Fig. 5, appears to he regular, although the author's frequency plot in Fig. 11 makes it appear rather irregular. Has the author attempted anY correlation between some of the major dircetions and the oricntntaion of the parent grain as determined by X-ray analysis? Also, in Figs. 4, 5 and 6 the cross-sections of the needles appear to be straightsided and regular. Have these directions been correlated with the matrix latttice? Dr. Mnrzkr 's method of interpretation of the orientation rclationships between the alpha. and beta phases is a bit uncertain and seems to wed more explanation. If this relationship, as staited is such that :L (1111 plane and a [I 10] direction of that plane in the precipitate is parallel to a. {110} p1ane and a [111] direction of that, plane in the matrix, there mill be a maximum of 24 possible orientations of the alpha phase within a. single grain of the beta phasc. This relationship is expressed strercographical1y in Fig. 13, ill which the locations of a11 of the alpha {111} poles for the 24 orientations of alpha me given. Fig. 12 chccks fairly closely with this thcoretical plot,. with a few exeeptions which may be due to the inaceuracy inherent in the method used by the anthor in determining the orientations of the segregates. The method might have been refined somewhat had corrections been made for the displacement of the slip p1ancs upon deformation.

Jan 1, 1933

By Stephen Birch

LATOUCHE, or the Beatson plant of the Kennecott Copper Corpn., is located in the Prince William Sound district of Alaska about 80 miles west of Cordova and 60 miles from Seward. Ore was discovered and claims located on Latouche Island in July, 1897. The mines were worked in a desultory manner until 1910, when the property was acquired by the Kennecott Copper interests. The first shipment of ore was made in 1904; only the higher grade ore was mined and no attempt was made to treat the ore until it was taken over by the Kennecott, company. Since that time the mine has been developed to produce 1500 tons a day and a mill has been erected for treating this tonnage, using flotation entirely. The orebody is more or less lenticular in shape with a maximum width of about 280 ft. and a length of about 800 ft. The southern end of the lens is split by a horse of waste for about 400 ft. The hanging-wall limit is a well-defined fault associated with a band of pyrrhotite, having an average dip of 60°. There is no defined foot wall, the value of the ore governing the limits of the mining; in one part of the mine, however, it is defined by a minor fault. The orebody is located in a shear zone of the country rock of graywacke and slate. The principal mineral is chalcopyrite associated with pyrite and quartz. The mine is located a few hundred feet from tidewater; the mill is located on the beach and the ore is hoisted direct from the mine through a vertical shaft into the mill bins. Until the past year practically all the mining had been conducted in open pits. During the past two years, the ore above the 200-ft. level has been developed and a system of stoping devised to recover this ore; however, this system has not been in use long enough to give any definite results as to costs or efficiency. It consists, principally, of dividing the orebody into stopes, across the full width of the orebody, 70 ft. wide with a pillar 30 ft. wide between the stopes. Raises are driven through the stopes at intervals of about 60 ft. and all the ore is broken by drilling from these raises; in other words, similar to a shrinkage stope, doing the drilling from the raises instead of setting up on the broken ore as is customary. The ground is very much broken up by clay slips and seams running in every direction. Shrinkage stoping had been

Jan 1, 1924