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By Charles Goodale

THE principles and theory on which the U. S. mining law of 1872 was based are well understood, and have been discussed at great length by many writers. The papers by Dr. R. W. Raymond1 in the Transactions of the American Institute of Mining Engineers have covered the subject very fully, with explanations of practical results in many adjudicated cases. It is believed that the following instance of the application of the law in recent years will have some weight in a discussion of proposed changes in our mining laws. The litigation between the St. Louis Mining & Milling Co., and the Montana Mining Co., Ltd., a British corporation, over portions of the Drumlummon lode covered more than 20 years, and resulted in a judgment for damages in favor of the St. Louis Co. of such an amount that the Montana Co. declined to pay the judgment, and therefore lost the entire property. The Drumlummon lode claim in the Marysville district, Mont., was located in 1876 by Thomas Cruse. When he staked out his claim, he assumed that the discovery on the Drumlummon vein, and another showing of mineral about 200 ft. distant, were on the same vein, and the center line of the claim was given a course of N. 57'2'E. Development of the Drumlummon vein soon showed that its strike was about N. 15 E., and that the other outcrop was on the North Star lode; so it was inevitable that the Drumlummon vein would cross one or both side lines of the location, and the Montana Co. found it advisable to acquire adjoining claims on both sides of the Drumlummon, in order to avoid possible litigation over apex rights. They bought the Marble Heart, but would not purchase the Hopeful (see Figs. 1 and 2), at the terms proposed for the reason that exploration in the Cruse level had shown the vein to be barren in that region. The owners of the Hopeful were sinking an incline from that claim in 1889, and the Montana Co. enjoined them, contending

Jan 5, 1914

By Robert T. Howard, Morris Cohen

THE purpose of this paper is to direct attention to the lower part of the austenite transformation diagram, or TTT curves, where considerable uncertainty still exists as to the blending of the bainite and martensite reactions. The dissimilarities between these two low temperature trans- formations have been summarized recently by Troiano and Greninger.1 Of particular importance to the present work is the fact that martensite formation, unlike bainite formation, is not suppressed by the fastest quenching rates attainable. However, most of the investigations in this direction have been concerned primarily with the start of the martensite transformation [(M,)] during cooling, rather than with the quantitative aspects of the subsequent reaction on either further cooling or isothermal holding. Several years ago, Cohen2 suggested a form of transformation diagram which reconciled, at least schematically, the isothermal characteristics of the bainite transformation with the insuppressible nature of the martensite transfoi mation. In essence, the diagram consisted of a family of horizontal lines (representing the progress of the austenite-martensite reaction during quenching) which were interrupted in point of time by the bainite family of C-curves extending down from higher temperatures. This picture received later support by metallographic3 and dilatmetric4,5 studies, but the techniques employed were not sufficiently critical to substantiate some of the details. Elmendorf6 and Grange and Steward7 have shown that the Greninger-Troiano metallographic techniques may be used not only for [M,] determinations, but for studying the course of further austenite decomposition. In fact, the latter investigators have observed the amount of martensite formed as a function of temperature below [M,] in fourteen commercial steels. In the present paper, the Greninger- Troiano technique has been combined with the lineal method of Howard and Cohen9 to provide a unique, quantitative treatment of the austenite-martensite reaction. Furthermore, isothermal transformations have been similarly measured on holding at temperatures above and below M,, thus permitting a fairly detailed presentation of the lower part of the conventional austenite transformation diagram. EXPERIMENTAL DETAILS Materials The steels, listed in Table I, were selected for study because they exhibit a satisfactory range of M, temperatures and have not received as much attention as the lower carbon grades. They were prepared as 30 lb induction furnace heats in the laboratories of the Vanadium-Alloys

Jan 1, 1947

THE metal iron has physical and chemical properties which are somewhat different from those of steels, but a knowledge of the pure metal is a useful starting point in studying the behavior of steels. Solid iron exists in two different crystalline forms, called alpha (a) and gamma (?) iron, the former being the ordinary form at room temperature. When heated above the "A2 point," 1400°F. (760°C.), the metal becomes non-magnetic, and at the "As point," 1670°F. (910°C.), it undergoes a change in crystalline form to become gamma iron. In the range 1400 to 1670°F., it is sometimes called beta (0) iron to distinguish it from the magnetic alpha, but the two are identical in crystal structure. When gamma iron is further heated to 2550°F. (1400°C.), it changes into delta (d) iron, which is identical with beta or non-magnetic alpha iron. Pure iron melts (in a hydrogen atmosphere) at 2795°F. (1535°C.); the melting point is generally lowered by alloys or impurities. PROPERTIES OF IRON AT HIGH TEMPERATURES Many of the properties of iron undergo abrupt changes at the transition temperatures. (1) For example, in heating through the As point a sudden shrinkage in volume occurs. Similarly, melting is attended by sharp physical changes such as an increase in volume. Table 27 contains a summary of the measured physical properties of pure iron at several temperatures. Usually the properties change smoothly within the range of stability of a given form, but this is not always the case. For example, the specific heat reaches a sharp maximum at the A2 point although no transformation occurs. Solvent Powers of Liquid Iron. Liquid iron is capable of dissolving most of the other metals and many nonmetallic elements as well. Of the metals which are liquid at the melting point of iron only lead, silver, and bismuth refuse to dissolve to an appreciable extent. The non-metals presumably dissolve by virtue of the formation of an iron compound; for example, sulphur is thought to dissolve as the compound FeS. However, there is no satisfactory method of proving that this

Jan 1, 1944

By Frank R. Corwin, Selden S. Rodgers

PAGE I. Introduction,........... 383 11. Brief History of Present MacDoUgall Plant,.... 384 III. First Experimental Work on Increasing Capacity of Furnaces, 385 IV. Effect On MacDouRall Plant of IncreaBed Draft from New Smelter Stack,,.......... V. Increasing the Capacity of the MacDouGall FurnaceS,.. 391 (A). Test of Arthur Crowfoot on Increasing Capacity,.... (a). Description of Test,........ (6). Discussion of Results Obtained from Test,... 393 (B). Investigation Carried Out by John A. Church, Jr.,... 395 (a). Advantages of High Speed,......398 (C). Effect on Regular Operation of Department by Applying Results Obtained from Experimental Work ..... 399 (D). Fundamental Principles Involved in Increasing the Tonnage, . 400 VI. Treatment of an INcreased Amount of Ore Screenings,.. 401 VII. Maximum Percentage oF Ore Screenings in a MacDoUGall Feed, 403 VIII. Tests to Further Increase Capacity of Furnaces,... 406 IX. Tests to Decrease PercentaGe of Flue Dust made by MacDouGall Furnaces,............. (A). Repath-Marcy Furnace......... 408 (B). Modified Hepath-Marcy Furnace,....... (C). Crouse Furnace Designed for Dust Prevention,.... 413 (a). Tests on Crouse Furnace,....... X. Concrete Hearths,.......... 419 XI. Conclusion,............ I. Introduction. Since the first installation of MacDougall roasters at the Great Falls smelter of the Anaconda Copper Mining Co., the capacity of the furnaces.has been more than doubled. During the first nine or ten years of the operation of the MacDougall department the tonnage treated by the furnaces remained practically unchanged. Experimental work carried out in 1906, however, showed that increasing the draft of the furnaces would bring about an increase in capacity. In 1909 the MacDougall department was connected to the new smelter stack and

Jan 1, 1914

By Dean S. Rogers

The conventional role of exploration, development and grade control is examined in this paper within the context of the many and varied types of gold occurrences which are found at the Dome Mine. The account endeavours to trace the development of the total ore evaluation process, from diamond drilling through the exploration and drifting stage, to the stope development and planning phase of the operation, with an emphasis on sampling techniques and assaying procedure. The concept of ore reserve calculations is developed and the practice of grade control is described. In summary, the role of the geological, the engineering and the mining department is presented in relation to the contribution each has to make in the evaluation and exploitation of ore from one of the world's classic Archean gold deposits.

Jan 1, 1985

By J. E. Hilliard

Various methods are given for estimating the number per unit volume and average size of convex particles from measurements on a projection through a slice of the structure. The determination of the size distribution is considered specifically for spherical particles. The results are applicable to any type of transmission microscopy and also to the correction of measurements made by reflected light on semitransparent materials. WITH the advent of electron transmission microscopy, the metallurgist is confronted with the problem of relating a projected image to the three-dimensional properties of the structure. This paper deals with the estimation of the number per unit volume and size of particles dispersed in a matrix. The case of convex particles will first be treated (the results will be applicable as approximations to particles of more general shape) and then spherical particles will be considered specifically. The latter represent a special case frequently encountered in practice and one which is also amenable to a calculation of the effect of overlap on the observed particle-size distribution. Although the present treatment was prompted by the needs of the electron microscopist, the results are applicable to transmission studies with any type of radiation. In addition, they can be used in the analysis of semitransparent materials by reflected light, the depth of light penetration corresponding to the thickness of the slice or section used in the transmission studies. 1) CONVEX PARTICLES 1.1) General Expression for N,. We will suppose that a "center" (such as the center of mass) is assigned to each particle. The convention used for defining the center is immaterial providing it does not depend on the orientation or location of the particle. Consider a slice through the structure having a pair of parallel faces a distance t apart. It will be assumed that the slice is randomly located with respect to its perpendicular distance from some fixed point, but it is not necessary to assume that its orientation is random. Our problem is to deduce the relationship between the number of par- ticle images seen on an orthogonal projection through the slice with the number, Nv, of particles per unit volume in the original structure.* *Symbols are listed in the Table. The expected number of particles with centers lying within the slice is Nvt per unit area. In addition, there will be elements in the slice contributed by particles whose centers lie without. The number of such elements will be the same as the number of intersections occurring on a two-dimensional plane through the structure; namely N~K, where K is the mean distance, Fig. 1, between tangent planes to a particle averaged over all particles, i.e., Where Ni is the number of particles of class i having the same shape and size, and pi (4, 8) is the probability that an i particle will have a given orientation with respect to the slice. If the particles are randomly oriented, then K is independent of the orientation of the slice and equal to the mean cali-per diameter. The total number of particle elements in the slice is therefore Nv(t + K) per unit area, but fewer will be seen as separate images on the projection plane because of overlap. If MA is the number of elements "lost" by overlap, the number of images per unit area will be NA = Nv(t + K) -MA 121 MA is a function of the slice thickness and must vanish at t = 0. As t increases, NA at first increases, reaches a maximum, and thereafter decreases as the overlap term MA becomes predomi-

Jan 1, 1962

The annual spring excursion of the College of Mines, University of Washington, is being made to the Coeur d?Alene region of northern Idaho. A party of 15 students and, instructors is visiting the Bunker Hill and Sullivan mine, mill and smelter at Kellogg, and several mines and mills in the neighborhood of Wallace and Mullan.

Jan 5, 1917

By A. G. H. Andersen, A. W. Kingsbury

SILICON bronzes containing iron are used to a considerable extent in industry, under the trade name of P.M.G. alloys. Various classes of wrought alloys fall in the composition range 1.5 to 3.5 per cent silicon, and 0.5 to 2.5 per cent iron. Castings may contain as much as 6 per cent silicon and 3 per cent iron at present. The constitutional diagrams of these alloys are thus of considerable practical importance. Copper-silicon-binary alloys have been thoroughly investigated by a number of workers, the latest reports being those of C. S. Smith1 and of A. G. H. Andersen.2 Although much work has been done on iron-copper alloys,3 recorded investigations on the copper-rich copper-iron binary constitutional diagram are not numerous. Tammann and Oelsen4 determined the solubility limits of iron in copper by means of magnetic measurements, and found that the solubility of iron in copper amounts to a fraction of one per cent at 400°C., increasing slowly to one per cent at 800°C. From 800°C., the solubility increases rapidly and attains 4 per cent at 1100°C. Hanson and Ford,5 using electrical resistivity measurements and the microscope, determined a somewhat different solubility limit. Of earlier X-ray works on the copper-iron system, very little has been published. The work by Bradley and Goldschmidt6 on copper-iron-aluminum alloys includes some information on the copper-iron binary. These investigators conclude that substitution of iron in the copper lattice decreases the spacings, which is contrary to the evidence of the present work. Hanson and West7 have investigated the ternary alloys of copper with iron and silicon. Although their diagrams are valuable contributions to the understanding of these alloys, they did not recognize the kappa phase,12, 7,8 and their diagrams do not everywhere conform to the phase rule. The present work contains a check by means of X-rays of the solid solubility limit of iron in copper, and an X-ray investigation of the ternary-phase diagram, which, owing to present conditions, it became necessary to curtail considerably. PREPARATION OF SAMPLES Castings weighing about 75 grams were melted under vacuum. The charges were made up of ingot iron, copper cathodes from Laurel Hill, and refined silicon supplied by the Electrometallurgical Co. Alundum crucibles were generally used. The exceptions were alloys 77 and 78, which were melted in graphite crucibles. The ingots were annealed at 800°C. for one week, then samples were cut for chemical analysis. Longitudinal sections of the binary alloy ingots were hammered into plates 3 in. thick. Wherever possible, these plates were homogenized at temperatures ensuring

Jan 1, 1942

By W. C. Hagel, H. J. Beattie

Seven austenitic alloys of varions base compositions and minor-alloy additions were solution-treated, aged systematically between 1200oand 1800oF, and examined by X-ray and electron metallography. Intragranular preczpitations of µ, Laves, s, ?', Ni3Ti, and x phases were observed as a function of composition and aging time and temperatwre. Phase solubility limits were detevtnitzed within 100Fo intervals. These inter metallic compounds fall into two distinct general classes, and whichever class predomznates depends on base composition. It has become increasingly evident that multicom-ponent austenitic alloys are well characterized by their precipitation processes. Since certain groups of elements act as one, the relationships among these processes are reasonably simple; complete identification of such processes is usually attainable by a systematic aging study with a combination of techniques centered on microscopy and diffraction. Several nickel- and cobalt-base alloys illustrating cellular precipitation and its interaction with general precipitation were reported previously.1 The group of alloys covered in the present paper demonstrates precipitation-hardening reactions involving two distinct classes of intermetallic compounds where the predominating class appears to depend on base composition. This dependency ties in with a crystal-chemistry regularity first observed some twenty years ago by Laves and Wallbaum but never amplified to our knowledge. Results of electron-microscope and X-ray diffraction studies on systematically aged hot-rolled alloys known commercially as S-816, S-590, Rene-41, Incoloy-901, M-308, and M-647 are reported here. Some of these alloys have previously undergone minor-phase analyses by other investiators. Alloy S-816 was investigated by Rosenbaum, Lane and Grant,3 and Weeton and Signorelli.4 Rosenbaum found only CbC in hot-rolled bars. Lane and Grant found CbC and a small amount of M6C in the cast structure and stated that both carbides form during aging, most of the precipitation being CbC. Weeton and Signorelli found CbC, M23C6 and a weak indication of a phase after a slow step-down cooling cycle from 2250°F. Rosenbaum also investigated hot-rolled samples of S-590 and identified CbC and M6C. Preliminary information on Rene-41, gained partly from the present work, was reported by Morris.5 Long-time precipitation phenomena in Incoloy-901 at 1350°Fwere investigated by Clark and Iwanski.B heir raw data re- semble those of our present heat with 0.1 pct B, while their interpretation of these data resembles our interpretation of data from another heat with only 0.001 pct B; they made no statement as to boron content. No previous minor-phase studies of alloys M-308 or M-647 have been reported. EXPERIMENTAL METHODS Table I gives alloy compositions in both weight and atomic percent. Specimens were solution-treated from 1700º to 2200ºF, aged at logarithmic-time intervals up to 1000 hours between 1200 and 1800 F, and examined in accordance with procedures previously described in detail. ' ' Phase extractions were carried out in electrolytic cells containing 800 ml of either 7 pct HC1 in denatured ethanol or 20 pct H3PO4 in water. After electrolysis for 48 hr at 0.1 to 0.2 amp per sq inch, residues were separated by filtration or centrifuging. X-ray powder patterns of residues were recorded on a diffractometer for accuracy and on film for sensitivity. Lattice parameters were calculated by least-squares analyses of indexed sin 8 values, and relative abundances were estimated from intensities of strongest lines of each phase. These phase abundances denote relative amounts with respect to each other rather than to the alloy. Mechanically polished specimens were etched in a freshly mixed solution of 92 pct HC1, 5 pct H2SO4, and 3 pct HNO3. Parlodion replicas for the electron microscope were chromium-shadowed in high vacuum at a glancing angle of 20deg. All electron micrographs are reproduced here with the shadowing source above. The correspondence betweenelectronmicrostructures and phases identified by X-rays was established by a high redundancy of correlation between relative amounts at different stages of aging and examination above and below critical transformation or solubility temperatures. EXPERIMENTAL RESULTS S-816 and S-590—The phases found in S-816 and S-590 after various aging and solutioning treatments are listed in Table 11. These data and the observed

Jan 1, 1962

By C. Q. Payne

(New York Meeting, February, 1912.) THE art of crushing ores and other materials by means of rolls is a comparatively recent one. While the first record of rolls using iron crushing-surfaces dates back to the year 1806, when they were employed in Cornwall, their principal development has taken place during the last 30 years. To Stephen R. Krom belongs the credit of the pioneer in introducing the belted high-speed roll, which has had its origin and a marked development in this country. His notable contribution to the art was in the use of a single bed-plate or frame supporting the roll-shafts, and to which levers holding the movable roll-bearings were pivoted. He also made use of steel tension-rods to support the crushing-strains, and of hammered-steel tires for the crushing-surfaces. These changes brought the design of crushing-rolls to a high level. Following closely thereon, about 1885, W. R. Eckart conceived the idea of the swivel or ball-and-socket support for the roll-shaft bearings. This is an excellent mechanical conception, especially for bearings held against a spring pressure, and while it may not be necessary for all types of rolls, yet it has been quite generally adopted by other roll-designers, and illustrates the refinement which roll-construction has now reached. Other engineers, as for example, Argall, Vezin, Roger, and Sturtevant, to mention only a few among many, have also given the closest attention to the various details of rolls, such as the frame, springs, bearings, and shafts, and have developed many novel and original designs. It has remained, however, for the boldness and originality of Mr. Edison to extend the field of crushing-rolls in two new directions, and to cause them to exercise new functions. In developing crushing-machinery for his Portland cement works, Mr. Edison constructed ? giant " rolls, having a diameter of 6 ft. and a length of. face of 7 ft.

Jun 1, 1912

By T. E. Ockershauser

The Southwest Antioch Oil Field located in T2&3N - R2&3W, Garvin County, Okla., was discovered in February, 1946, by The Globe Oil & Refining Co. and The Vickers Petroleum Co. at their Melinda Gibson No. 1. Oil production was encountered at a depth of 6,525 ft in 14 ft of lower Pennsyl-vanian sandstone. The producing sand, locally called the ."Gibson" or "Third Deese," is a sand bar deposit strung along the west flank of the Pauls Valley uplift in a northwest-southeast direction. The oil reservoir is defined to the east by the edge of sand deposition along the uplift and to the west by the gradation of sand into shale. Within the Antioch Unit, the sand dips from 150 to 400 ft per mile southwesterly and has a pay thickness varying from 10 to 55 ft and averaging 28 ft. Several areas of Gibson production have been developed, including the Katie pool on the south, the Elmore Area of the Southwest Antioch Gibson Sand pool. the Southwest Antioch Gibson Sand pool proper, the Southwest Maysville pool and the New Hope pool on the north. Production extends over a belt 22 miles long by about two miles wide and is continuous except into the Katie and New Hope pools. It appears that drilling will soon prove these intervening areas productive. To March 1, 1950, approximately 18,000 acres have been developed with 450 Gibson wells. It is likely this count will ultimately reach 32.000 acres with 800 wells. RESERVOIR The natural production of oil from the Gibson reservoir is primarily due to solution gas expansion though gravity also plays a part. There is no indication of water drive or evidence that an initial gas cap existed. Gibson oil has a stock tank gravity of 43" API and was saturated at the original reservoir pressure of 2.925 psi. It contained 1,3440 cu ft of gas per bbl in solution and had a high shrinkage of 70 per cent. Connate water amounts to 15 per cent. Reservoir temperature is 130°F. Porosity averages 15.5 per cent and permeability ranges from less than one md to over 1.000. Based on meacurement of 400 core plugs from 15 wells, 78 per cent of the permeabilities fell within the 10 to 1,000 md bracket and averaged l67. Primary oil recovery is estimated at 140 bbl per acre-ft or 22 million bbl for the present 137-tract unit. Due to unitization

Jan 1, 1951

By T. E. Ockershauser

The Southwest Antioch Oil Field located in T2&3N - R2&3W, Garvin County, Okla., was discovered in February, 1946, by The Globe Oil & Refining Co. and The Vickers Petroleum Co. at their Melinda Gibson No. 1. Oil production was encountered at a depth of 6,525 ft in 14 ft of lower Pennsyl-vanian sandstone. The producing sand, locally called the ."Gibson" or "Third Deese," is a sand bar deposit strung along the west flank of the Pauls Valley uplift in a northwest-southeast direction. The oil reservoir is defined to the east by the edge of sand deposition along the uplift and to the west by the gradation of sand into shale. Within the Antioch Unit, the sand dips from 150 to 400 ft per mile southwesterly and has a pay thickness varying from 10 to 55 ft and averaging 28 ft. Several areas of Gibson production have been developed, including the Katie pool on the south, the Elmore Area of the Southwest Antioch Gibson Sand pool. the Southwest Antioch Gibson Sand pool proper, the Southwest Maysville pool and the New Hope pool on the north. Production extends over a belt 22 miles long by about two miles wide and is continuous except into the Katie and New Hope pools. It appears that drilling will soon prove these intervening areas productive. To March 1, 1950, approximately 18,000 acres have been developed with 450 Gibson wells. It is likely this count will ultimately reach 32.000 acres with 800 wells. RESERVOIR The natural production of oil from the Gibson reservoir is primarily due to solution gas expansion though gravity also plays a part. There is no indication of water drive or evidence that an initial gas cap existed. Gibson oil has a stock tank gravity of 43" API and was saturated at the original reservoir pressure of 2.925 psi. It contained 1,3440 cu ft of gas per bbl in solution and had a high shrinkage of 70 per cent. Connate water amounts to 15 per cent. Reservoir temperature is 130°F. Porosity averages 15.5 per cent and permeability ranges from less than one md to over 1.000. Based on meacurement of 400 core plugs from 15 wells, 78 per cent of the permeabilities fell within the 10 to 1,000 md bracket and averaged l67. Primary oil recovery is estimated at 140 bbl per acre-ft or 22 million bbl for the present 137-tract unit. Due to unitization

Jan 1, 1951

By HARRISON W. CRAVER

LIBRARIES are universally recognized as essential to modern civilization. In a world that gets most of its learning through the printed word, storehouses of print are a vital necessity. In this regard engineering differs in no way from the other learned professions, but until recent times the library needs of engineers have received rather scant attention. When the engineering profession was more of an art and less of a science than it is today, when each problem was solved more through the results of experience than by applying scientific principles, literature was less helpful. The engineer of today, however, is aware that his activities rest upon a scientific foundation and consequently comprehensive books dealing with more limited fields are now being published. Another difficulty for the operating engineer in the past was that the published works on engineering were written chiefly for use as college texts. A third obstacle to the development of engineering libraries has been the lack of librarians with experience in engineering.

Jan 1, 1938

By M. R. Campbell

Coal is the geological product of entombed vegetal tissues. This view of its origin led Stopes and Wheeler to define it as "mummified plants." They evidently intended this term to be used in a broad way and to mean the preservation of the organic material, as such, regardless of the means employed to accomplish the purpose. The term " coal" should be regarded, therrfore, as broadly generic, and applicable to all accumulations of vegetal tissues as soon as they are covered and protected either by water or by earthy material. In this sense peat should be regarded as the first stage of coal formation and the term coal should include the resultant products of transformation in all other stages of the process until they have lost all resemblance to the original matter from which they were derived. If this idea of the development of coal is accepted and it is admitted, as the geologists claim, that the forces which produced this transformation of the coal have been active since vegetation began to grow upon the land, and are still in operation, it is obvious that somewhere in the world there are all gradations of this material from peat just forming in the swamps of today to graphitic anthracite which presumably marks the most advanced stage that can be recognized with certainty as belonging to the series. Some of these coals, particularly those occurring in the upper part of the series, are fairly well known because they are the ones that are most widely distributed and have been mined and utilized most extensively. On the other hand, the coals in the lower part of the series are but little known because they are not so abundant and, owing to their relative inefficiency, have been only slightly exploited and utilized, especially in regions where the better coals are abundant. The result of these conditions is that much research work has been done on coals of the higher ranks and a great body of facts regarding their physical and chemical properties and the uses to which they are best adapted has been accumulated, but little information is available regarding the coals of the lower ranks. Many able scientists, particularly chemists, have attempted to bring some order of the chaos of coals of various compositions and uses by

Jan 1, 1930

By John C. Kleiber, George M. Meisel

From time to time since the initial installation of an experimental flotation section in 1940, Permanente Cement Co. has made efforts to beneficiate the low-grade limestone fraction which occurs in its deposits at Permanente, Calif. The encouraging results outlined in this article are the result of Permanente's latest effort. THE PERMANENTE LIMESTONE AND THE REASON FOR ITS BENEFICIATION The Permanente deposit is a sheet of Calera limestone over 700 ft thick lying within the Franciscan sediments of the San Francisco peninsula. Limestone suitable for cement manufacture underlies, overlies, and is interbedded with low-grade limestone and chert. Andesite intrusions are found as a secondary gangue. The limestone is identified as follows:

Jan 3, 1964

By Orson Shepard

THE term "electrocapillary amalgamation" is used in this paper to designate amalgamation processes that depend upon electrocapillary phenomenon; i.e., the action of an electric current upon the surface tension of mercury at the contact with aqueous solutions. Electro-capillary amalgamation is selected as a name for these processes because the electrocapillary phenomenon has been found to be the effective agent in the use of sodium amalgam, as well as in the various processes using an electric current from a source outside of the amalgam. Amalgamation processes that depend upon supplying an electric current to the amalgam from an outside source, such as batteries and generators, have previously been called electrical amalgamation processes. There has been a tremendous amount of experimental work done on amalgamation processes involving the use of an electric current, as shown by the large number of patents issued on these processes: the earliest in 1885 and the latest in 19341. Regardless of all the experimental work, the fundamental principles causing the operation of electrocapillary amalgamation processes have not been described. The explanation usually given is that an electric current keeps the amalgam bright and clean. Patent No. 328532 states: It is well known that when amalgam plates are used for collecting gold and silver from their ores the surfaces of these plates are liable to become tarnished or sickened by certain substances contained in the ores or in the current of water which is employed to carry the ore over the plates, and that in this condition they are unfitted for amalgamating the particles of gold and silver. To prevent this and to keep the surfaces of the amalgamation plates always bright and in a better condition for catching and amalgamating the particles of gold and silver I employ electricity in the following manner:. . . A similar explanation is given 49 years later, in patent No. 1953364: The sodium (Na) ions lose their charge at the cathode becoming sodium atoms, which do not react with the electrolyte, but follow the grounded electrical current through the mercury body producing in their passage sodium amalgam and liberate themselves in the amalgamation compartment when brought in contact with the fed

Jan 1, 1936

By A. T. Yu

As the first loads of Noamundi iron ore rumbled into the new 54-in. Gyratory Crusher on March 30, 1968, one of India's largest and most modern iron ore processing complexes began operations. The completion of the $13 million mining and processing complex brought to a successful conclusion the second chapter of a phased expansion program initiated in 1958 by India's gigantic Tata Iron and Steel Co. The completed complex will yield annually 2.5 million tons of washed, sized ore and sinter fines destined for Tata's furnaces at Jamshedpur. Hewitt-Robins Div. of Litton Industries was awarded the turnkey project on the basis of world- wide competitive bids. Eighty miles southwest of the city of Jamshedpur, Noamundi lies on an approximate geographic grid of 22º-5' latitude north and 85º-30' longitude east. The mine is approximately 600 ft above sea level.

Jan 11, 1968

An informal meeting of the Conferees of the Development Committees of the four Societies was held in New York on July 2, 1919, at which the scope of the work was considered, and a sub-committee oil Procedure, consisting of the chairmen of the Conferees from each of the four Societies, was appointed to arrange the program for and the time and place of the first formal meeting. The Conference subsequently adopted the name, " The Joint Conference Committee." The Joint Conference Committee convened at the Hotel Montclair, Montclair, N. J., Aug. 13, 14, and 15, and in New York, Sept. 15, 16, and 17, 1919. The Committee has divided its report into two parts, that covering the public activities and that covering the society activities of common interest to the four societies.

Jan 12, 1919

By M. A. Hosmer, Job Goostray, R. F. Harringon

In this paper, as in so many discussions of an historical nature, there is little chance for original material and much has had to be rewritten from older papers, documents, accounts, reports, and the like, some of which are of doubtful authorship or contain conflicting statistics. Fully aware of these pitfalls, the authors have tried to quote the origin where possible, and also to seek further confirmation when the statement warranted it, but they cannot assume responsibility for certain facts and dates. The Encyclopedia Britannica was frequently consulted. The authors wish to acknowledge assistance from Mackintosh-Hemp-hill Co. (formerly the Fort Pitt Works) and also from officials of the Watertown Arsenal who loaned valuable books and gave much necessary information. They are particularly indebted to Colonel Dickson of that institution. The data on modern guns were furnished by Mr. F. Brauer of the Watertown Arsenal; Mr. H. S. Chaffee assisted by obtaining records and data of work carried on by the Builders' Iron Foundry of Providence, R. I. Three Epochs in History of Cannon Among the great industries of New England, the manufacture of iron was the first to receive attention. Iron ore in considerable quantities was known to exist within the territory of the Massachusetts Bay Colony; and as early as 1629 some steps appear to have been taken toward the manufacture of iron by the Court of Assistants in London, under whose patronage the colony was founded. During the next ten years, deposits of bog ore were found in numerous ponds in the Plymouth Colony; and, in 1652, iron manufacture was begun at Raynham. The "Old Colony" was known as the main seat of this industry in New England, out of which grew a concern which was later to become one of the principal

Jan 1, 1925

By J. W. Schroeder

SEAMLESS pipe, the product produced from piercing a solid round billet of steel by the Mannesmann process, was first produced in the latter half of the 19th century, the Mannesmann machine having been patented in 1885. The products of other processes also have been termed seamless pipe; for example, the cylindrical section produced by "cupping," which consists of forming a cup from a flat plate or disk and further elongating the cup into a tube by passing it through a set of reducing dies. The purpose of this paper is to discuss some of the more important metallurgical factors and their relationship to the economical production of seamless pipe produced by the Mannesmann piercing process. The first seamless tube plant in America was established at Shelby, Ohio, in 1891, and was employed in the manufacture of bicycle tubing. For a number of years the bicycle industry was the only user of seamless tubing, and this tubing was produced by hot-rolling pierced billets imported from Europe and finishing on the cold drawbench. At the turn of the century, the automotive industry was responsible for an increase in the demand for seamless tubing. The growth of this industry was the dominant factor leading to the phenomenal growth of the petroleum industry, which in turn created a tremendous demand for seamless pipe. In addition; the old lapweld iron boiler tubes for stationary and locomotive boilers were replaced gradually by seamless tubes. Since 1929, the production of seamless steel pipe and tubes has increased over loo pct. In 1929, 1,459,9031 net tons of seamless pipe was produced, including both hot-finished and cold-drawn material, as compared with 3,087,3122 net [ ] tons in 1948. Table I gives the distribution of seamless pipe by classes for 1948. METALLURGICAL PROBLEMS From a metallurgical standpoint, the production of seamless pipe has presented many problems. Practically every type of steel, carbon and alloy, with the exception of the superalloys developed during World War II, has been pierced and rolled successfully into tubing. This includes bessemer, open hearth, by the stationary and duplex processes, and electric steels. The range of sizes produced is no less staggering to the imagination, when it is considered that the hypodermic needle, which is 0.016 in. diam with a wall thickness of 0.004 in., and pipe for gas or oil transmission lines, with a 26 in. OD, are both seamless tubes. Between these extremes, the range of diameters and wall thicknesses meets most present-day demands for seam-

Jan 1, 1951