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By Emile Gyss

THE speed of drilling rock has become an impor-tant factor in mining operations, while the place-ment of holes, kind, and quantity of explosive used. are equally important. These are a function of the rock hardness and toughness. Both of these fac-tors must be considered in compiling a table that will enable a mine operator or engineer to estimate drilling speeds in a given rock, knowing its hardness, and from its toughness, the dynamite required. The hardness of a homogeneous rock may be defined as its resistance to a penetrating medium, such as a drill-steel bit, and toughness, its resistance to with-stand rupture by the tearing apart of its minerals or parts of the same mineral. Rock hardness, as it has here been defined, is a function of the hardness of the component grains composing it, as well as grain size, shape, arrangement, and binding minerals. Rock tough-ness depends on substantially the same factors, but is measured by a totally different method. The units in which rock hardness is usually ex-pressed are either relative values or alphabetical desig-nations which carry no definite quantitative meaning. R. M. Raymond has suggested the measurement of com-posite rock hardness, based on mineral hardness as ob-tained by the Moh scale. This is done by multiplying the percentage of each mineral in a rock by the Moh mineral hardness and dividing by 100. These values convey a clearer conception in the minds of men in-terested in rock work -and are the basis of the units used in Tables 1 and 2. The hardness of rocks as it has been variously de-fined may be determined by different methods. The first method is one in which the proportionate average of the hardness of minerals making up a rock is the basis for classification. The other factors of grain size, shape, arrangement, and binding power are not considered.

Jan 6, 1927

By Hugh Henton

THIS paper is the result of an investigation made in association with Dr. Charles H. Fulton. Early in 1918 a search was started for methods of utilizing, in the manufacture of basic refractories, certain domestic resources in magnesites, dolomites, and magnesian limestones. Much information was collected during that year and during 1919 regarding magnesite and dolomite deposits. During 1920 and 1921 a research was made into methods of calcining dolomite and separating magnesia therefrom. Some success was attained and many new ideas were brought out in connection with the preparation and utilization of magnesia in the form of "caustic" or light-burned material as well as in the form of refractory or "dead-burned" material. Stimulated by this success, much advance has been made in manufacturing processes for the "plastic magnesia," so called, used for magnesia cement, stucco, flooring and otherwise in the structural industries.

Jan 3, 1926

THE subcommittee on Coal Mining, since its appointment, has been engaged in collecting data about subsidences in coal mines in this country, and it now feels that almost all of the available data about occurrences of this sort in bituminous mines has been collected. As most of the bituminous seams are nearly level, the records obtained give the problem in its simplest form, without complications due to the pitch of the seam. Similar data is being compiled for the anthracite regions and it is hoped that this will be ready for the 1927 meeting. Copies of the questionnaire, Appendix A, were mailed to all of the coal operators' associations, to most of the large operating companies and to many engineers, with the request that any data on the subject be returned to the committee, or that advice of any subsidences known be given. The replies to most of the questionnaires were general only, although some specific cases were given. Many of the companies were unable to reply to all questions, as they lacked the necessary data, but in nearly every case where accurate data was available, it was cheerfully furnished, and any additional information requested was secured. All specific cases of subsidence were followed up by correspondence, and in several cases by personal inspection. Figs. 1 to 31 were made from the information furnished. Table 1 gives measurements of elevations taken in one case at intervals from October, 1913, to May, 1918. With one exception, where the evidence cannot yet be released on account of a lawsuit, it is believed that the cases submitted with this report include practically all that have happened in bituminous coal mining in this country of which actual measurements were secured. Some of these have already been published in the excellent report by Young and Stoek,1 and some instances have been secured from other publications. In collecting these data, the subcommittee had the Engineering Societies Library extend the bibliography given in the bulletin mentioned above to date. This list is given in Appendix B.

Jan 2, 1926

Oct. 8-13, 1917 COMMITTEE ON ARRANGEMENTS H. A. BUEHLER, Chairman, W. E. McCOURT, Secretary, C. J. ADAMI, Southeastern, J. A. CASELTON, Entertainment, F. W. DEWOLF, Book, , E. F. GOLTRA, Finance, L. L. HUTCHISON, Tulsa, E. McAULIFFE, Transportation, P. N. MOORS, Reception, MRS. P. N. MOORE, Ladies, J. D. ROBERTSON, Publicity, VICTOR RAKOWSKI, Joplin., H. A. WHEELER, Excursions, A. THACHER.

Jan 7, 1917

By James Douglas

The development of the copper-resources of this country has kept close pace with the unfolding of its geographical area to commerce. In colonial days, when our English ancestors occupied only the Atlantic seaboard, insignificant quantities of copper were mined in Connecticut, New Jersey, and Pennsylvania, and the ore was shipped for treatment to England. The first steam pumping-equipment

Jan 1, 1891

By Patrick H. O’Neill

The Choco placers, mined continuously since the earliest expeditions of the Spanish conquistadors, were exploited by the Indians prior to the conquest. Platinum is found in varying percentages with gold throughout the Choco placers and is found in minor percentages in some placers in other parts of Colombia. The Choco Department is on the west coast of Colombia between the western range of the Andes and the Pacific Ocean and extends from the San Juan River north beyond Panama to the Caribbean. The first reference in European literature to platinum was by Julius Caesar Scaliger in 1557. He did not assign any name to it but referred to it as an infusible metal found in the mines in the New World. The Spaniards had given it the name platina, which is the diminutive for plata, the Spanish word for silver. Don Antonio de Ulloa first recorded the name while on an official visit to the Choco from Spain in 1735.

May 1, 1956

By M. G. Nicholas

The influence of deformation, relative movement and surface cleanliness on the strength of room -temperature "interparticle" bonds between copper surfaces has been studied. No bonding resulted when clean surfaces were merely pressed together, even under pressures of 50,000 psi. Bonding resulted, however, when clean surfaces were simultaneously pressed and moved relative to each other, some bonding occurring no matter how small the pressure or relative movement. Exposure of the clean surfaces to various chemicals inhibited bonding, none at all being produced by small relative movements. The size of the movements which first produce bonding between exposed surfaces depends on the nature of the chemical, being less than 0.002 in. for cleansing reagents and greater than 0.004 in. for lubricants, water and hydrogen sulfide. It is concluded from the experimental data that the prime requirement for bonding is the dispersal of surface films such as oxides and adsorbed contaminants. THE formation of interparticle bonds during the room-temperature compaction of powder metallurgy components greatly increases the ease of handling in subsequent production operations prior to sintering. The strength of unsintered compacts follows the same general trends as their density and hardness, but quantitative data are extremely Scarce. Quantitative correlation of the data on the overall strength of a compact with that of the individual interparticle bonds is virtually impossible due to the extremely complex geometry of powder compacts. Qualitatively, however, the strengths of unsintered compacts can be correlated with variations in parameters known to influence the extent of cold bonding, and hence interparticle bonding, such as surface cleanliness, relative movement, and deformation of the mating surfaces. Kuzmic and seelig4 found that contamination of powder particle surfaces with lubricants reduced the strength of unsintered iron and copper compacts. Interparticle shear has been shown to promote bonding by Train and Hersey7 while Gregory has shown that die rotation is beneficial. Eilender and schwalbe6 concluded that most bonding occurred during the early stages of pressing iron powder compacts when interparticle shear is one of the principal processes occurring. mile there can be little doubt that these and other factors, such as particle size and shape, affect the extent of interparticle bonding produced by compaction, evaluation of the influence of individual factors is not easy. Particle deformation and relative movement, for example, occur simultaneously during compaction, making any precise measurement of their relative influences difficult. Because of these and other difficulties encountered in studying interparticle bonding in actual powder compacts, the approach adopted in this study was to

Jan 1, 1963

By C. E. Wood

THE Blast Furnace Studies Section, Metallurgical Division, Bureau of Mines, has been working for several years on the mechanism of desulphurization of iron and steel by slags. The usual assumption that desulphurization takes place by diffusion of FeS from metal into slag and subsequent reaction of this FeS with CaO to produce CaS has seemed to us inconsistent with a number of experimental results we have obtained. We undertook, for example, to determine the proportion of sulphur in a slag present as FeS. An entirely satisfactory method of doing this has not yet been evolved. The results of extraction with metallic antimony led to an interesting conclusion, however. FeS is readily soluble in metallic antimony, either physically or by chemical reaction. On the other hand, CaS was found to be insoluble. Hence it would appear that by rapid extraction of the slag with antimony we might expect to determine the distribution of sulphur between iron and calcium. The results showed that much of the sulphur was present as FeS. In some instances the extraction of sulphur as FeS was almost quantitative. For example, in a slag containing 3.8 grams Fe and 3.7 grams S, extraction removed 1.18 grams S and 2.12 grams Fe. If all the iron present in the antimony had been FeS, 1.21 grams S would have been extracted. In another slag with 8.6 grams Fe and 0.06 gram S present, 0.14 gram Fe and 0.08 gram S were extracted. This was obviously extraction of sulphur as FeS within the analytical error and showed that FeS was present either in solution or as a dispersion. Attempts to determine the solubility of FeS and CaS in slag by quenching and ultramicroscopic investigation have indicated that the solubility of FeS is very low, and that reactions in the slag are probably not to be considered as homogeneous. A more detailed report on these theoretical considerations will be made at a later date.

Jan 1, 1939

By C. E. Jr. Reistle

ALL crude oils become more viscous when chilled, but the only oils that congeal and precipitate paraffin to such an extent as actually to cause production troubles are those that contain an appreciable amount of wax. In handling these oils of high wax content, three distinct problems may be encountered before the oil reaches the refinery. The first problem is the precipitation and accumulation of paraffin in the well, either in the oil string or on the face and in the pores of the sand. The second problem is the accumulation of paraffin and the congealing of oil in the transportation lines. The third problem is the precipitation of paraffin and the formation of tank bottoms.

Jan 1, 1927

By A. R. T. Denues

LIQUID-OXYGEN explosives commonly consist of a carbonaceous absorbent enclosed in a canvas wrapper and soaked with a liquid con-taining more than 90 mol per cent of oxygen. Investigation of these explosives in this country was initiated in 1917 by George S. Rice, then Chief Mining Engineer of the Bureau of Mines. The early development is summarized in two papers.1,2 Their characteristics, advantages and disadvantages were considered in a recent bulletin of the Bureau of Mines.3 Other publications of this Bureau4,5 treat the technology of these explosives and contain adequate references to pertinent literature. These investigations defined the properties of liquid-oxygen explosives and improved them greatly; however, an outstanding disadvantage is their high inflammability, a property of critical practical importance. These explosives as hitherto prepared are easily inflamed; the combustion resulting from an accidental ignition is particularly dangerous because of the ease with which it passes into detonation. For this reason the Bureau of Mines undertook a cooperative investigation, which has resulted in the development of fire-retardant treatment for the minimiza-tion or elimination of this hazard without materially impairing the explosive properties, including the ease of detonation. This presentation will offer a general description of the investigation and the outstanding results. Further phases will appear in subsequent short papers, and the entire investigation including the results of detailed experiments will be available in a forthcoming bulletin of the Bureau of Mines (Bull. 429). The effects produced by fire-retardant treatments of the carbonaceous absorbent and of the canvas wrappers were investigated separately, and the efficacy of combinations of these treatments with particular reference to the possibility of inflammation and to the development of detonation from inflammation was studied. The experimental explosive was pre-pared from a granular carbonaceous absorbent and the results described may be more or less unique for such a material. An extensive preliminary

Jan 1, 1940

By W. G. Matteson

I. Introduction...................................................... 436 (a) Extent of the Gulf Coastal Plain. (b) History of Important Gulf Coast Oil Pools. 1. Corsicans, Tex. 2. Spindletop, Tex. 3. Sour Lake, Tex. 4. Jennings, La. 5. Saratoga, Tex. 6. Batson, Tex. 7. Humble, Tex. 8. Caddo, La. 9. Vinton, La. 10. Naborton, La. 11. Red River, La. 12. Edgerly, La. 13. Goose Creek, Tex. 14. Damon Mound, Tex. 15. New Iberia, La. (c) Favorable Features of the Gulf Coast Pools. 11. General Topography and Physiography of the Gulf Coastal Plain.....440 111. General Stratigraphy of the Gulf Coastal Plain West of the 90th Meridian......................................................441 IV. Structural Types and their Characteristics.........................446 (a) hnticlinal Structure. (b) Structure of Salt Domes. 1. Domes of the Coast Prairie. 2. Domes of the Wold Region. 3. Recapitulation of Dome Structural Characteristics. V. Methods of Surveying and Prospecting............................. 454 VI. The Development of Salt Domes................- .................458 VII. Origin of Salt Domes...............4.............................461 (a) The Volcanic-plug Theory of Hager. (b) The Contemporaneous Sedimentation Theory of Norton. (c) The Theory of Upward Pressure Exerted by the Force of Growing Crystals, as Developed by Harris. VIII. Source of the Oil in the Gulf Coastal Pools.........................465 IX. Petrolific Value of the Salt Domes of the Wold Region..............467 X. Future Outlook.................................................. 467

Jan 1, 1918

By A. R. T. Denues

LIQUID-OXYGEN explosives commonly consist of a carbonaceous absorbent enclosed in a canvas wrapper and soaked with a liquid containing more than 90 mol per cent of oxygen. Investigation of these explosives in this country was initiated in 1917 by George S. Rice, then Chief Mining Engineer of the Bureau of Mines. The early development is summarized in two papers.1,2 Their characteristics, advantages and disadvantages were considered in a recent bulletin of the Bureau of Mines.,3 Other publications of this Bureau4, 5 treat the technology of these explosives and contain adequate references to pertinent literature. These investigations defined the properties of liquid-oxygen explosives and improved them greatly; however, an outstanding disadvantage is their high inflammability, a property of critical practical importance. These explosives as hitherto prepared are easily inflamed; the combustion resulting from an accidental ignition is particularly dangerous because of the ease with which it passes into detonation. For this reason the Bureau of Mines undertook a cooperative investigation, which has resulted in the development of fire-retardant treatment for the minimization or elimination of this hazard without materially impairing the explosive properties, including the ease of detonation. This presentation will offer a general description of the investigation and the outstanding results. Further phases will appear in subsequent short papers, and the entire investigation including the results of detailed experiments will be available in a forthcoming bulletin of the Bureau of Mines (Bull. 429). The effects produced by fire-retardant treatments of the carbonaceous absorbent and of the canvas wrappers were investigated separately, and the efficacy of combinations of these treatments with particular reference to the possibility of inflammation and to the development of detonation from inflammation was studied. The experimental explosive was pre¬pared from a granular carbonaceous absorbent and. the results described maybe more or less unique for such a material. An extensive preliminary

Jan 1, 1940

By J. Parke Channing

IT IS most appropriate for mining engineers and in fact for all engineers to perfect themselves in leader-ship, because in the last ten years there has been a growing realization on the part of capital that there is no man who by capacity and training is better fitted to manage industrial production than the engineer. In high places the engineer and particularly the mining engineer is coming into his own. We have Mr. Hoover as Secretary of Commerce, Mr. Hammond as the head of the Federal Fact-finding Coal Commission, and Prince Caetani as Royal Italian Ambassador, all mining engineers. More and more in all industries is the manager more likely to be an engineer than he was five, ten, fifteen or twenty years ago, and the feeling is that the man who has had a technical training, whether from going to a school or from burning the midnight oil, makes a better manager than the man who has not. We find in mining that the best man for a manager is one who has had engineering, training. The manager who comes up from the office, from the purchasing department or from the transportation department may make a fairly good manager but he is never so good as the man who has had a technical training. He cannot speak the language of his staff.

Jan 5, 1923

By G. L. Oldright

DURING 1919, in the face of high cost for labor and supplies and a rapidly dropping copper market, the management of the Ohio Copper Co. of Utah was left with an orebody that had been shown to be very low grade, and a mill that could not make a satisfactory recovery, even by flotation, because a considerable proportion of the copper minerals was oxidized. About seven million tons had been mined by the use of a caving system, the best of the broken ore extracted and milled, and the nature and copper content of the rest of the orebody fairly well determined. The rock of the whole mine was shown to run between 0.3 and 1.3 per cent. in. copper. As, the Ohio Copper orebody lies at the contact of the original sandstone (now altered to quartzite) with the quartz monzonite intru-sion that was the source of the mineralization at Bingham Canon, the rock was thoroughly shattered. It was shown further that the rock was mostly quart-zite, with a few quartz-monzonite "fingers" projecting into it. Although some of the old cleavage planes had been healed by resilicification so as to leave some of the copper minerals disseminated in the rock, a large proportion of these minerals was distributed along the cleavage planes.

Jan 10, 1923

By I. L. Dillamore

A purely geomentrical analysis based on oriented-growth relationships is presented to derive annealing-texture orientations in bcc metals from their- known deformation textures. The analysis takes as its starting point a description of- the bcc deformation texture and follows previous work on fcc metals in considering pvobable nurleation sites for recrystallization and the textural limitations on grains growing into a deformed matrix. The analy-sis accounts for the prominent and the minor coinponents of the annealing textures formed from two the deformation textures and can account for the ob-sem:ed temperature dependence of the annealing texture of bcc metals. THERE have been a number of investigations of annealing textures in bcc metals but few attempts to relate these textures to the deformation textures. This has been largely due to the lack of definition of both annealing and deformation textures, neither of which shows sharply defined orientations. It is, however, necessary to get a better understanding of primary recrystallization textures in bcc metals in view of increasingly exacting demands upon the quality of steel sheet for drawing purposes and as a necessary step towards the control of textures through processing. An analysis is presented here which relates annealing textures to deformation texture, by a purely geometrical method. This takes as its basis the oriented-growth theory of recrystallization and makes some reasonable assumptions regarding the make-up of bcc deformation textures and the limitations on growth relationships in bcc metals. Detailed information on this latter point is not available at the present time, and the present analysis may need to be streamlined or extended when such information is at hand. It is felt, however, that despite these limitations the analysis provides useful results and a valuable aid towards understanding the effect of processing variables. 1) BCC ROLLING TEXTURES Different workers have used a variety of descriptions for the texture developed in bcc metals by rolling. For the present purpose it will be assumed that two different deformation textures can be obtained: 1) a texture containing a major (112)[li0] component and a minor (001)[1i0] component for which increasing deformation causes the (001)[li0] component to increase at the expense of the (112)[li0] component, as suggested by Dillamore and ~oberts' (this is the texture predicted to arise starting from randomly oriented material); 2) a t~xture containing the above components and (111)[110] and (ii1)[112] components. This texture could arise from a material with an initial (110)[001] or (iil)[112] texture. It is well-known that the (ll0)[001] orientation rotates to (ii1)[112]that on roll-

Jan 1, 1965

COUNCIL OF SECTION DELEGATES Nicholas A D'Arcy, Jr, Chairman (Southern California Section) Charles Chapman, Vice-Chairman (Florida Section) Ben H Parker, Secretary (Colorado Section) Frontier Refining Co Boston Bldg Denver 2, Colorado

Jan 1, 1956

CLARENCE M. HAIGHT, Franklin, N., J. (communication to the Secretary*).-In that hart of Mr. Wilson's paper describing the Gilman cut-and-fill system, a few features do not appear to be fully explained. In what way is the waste used for filling obtained? The text mentions that, if waste is encountered when driving the filling raises, these raises are stopped until the fill is needed; that seems to suggest mining the capping for fill, which might make the backs of the stopes had as the stopes approach the top of the ore. If, on the other hand, the fill is brought to the raises in cars, are the crosscuts that are necessary in ore or waste? Is the cost of this fill included in the stoping costs given?

Jan 5, 1917

The American Institute of Mining Engineers, the American Society of Civil Engineers, the American Society of Mechanical Engineers, and the American Institute of Electrical Engineers have established the . Engineering Societies Employment Bureau under the management of their Secretaries. One of the purposes of the Bureau is to keep in touch with all engineering firms with a view to supplying them with desirable men. Plans are under way to assist in placing men who are retiring from the government service. The Bureau is not intended to be exclusively for the benefit of unemployed members, of the Founder Societies; non-members who are introduced properly will be registered. Information, registration forms, etc., may be obtained from the office of the Bureau, Engineering Societies Building, 29 West 39 Street, New York, Room 903.

Jan 1, 1919

By Carl D. Broadbent

In 1956, Kennecott Copper Corp. instituted a slope mechanics program. Its objective was to obtain effi-ient and safe pit slopes. Since then, Kennecott has onducted a great deal of research into the area, most otably at the Kimbley Pit. This paper, which describes the transitional work at this period and draws from the pertinent experimental work done by others, paves the way for the next step of the program: refining the design process and applying it for profit. The goal of slope mechanics is to achieve efficient and safe pit slopes. In the case of ultimate mine slopes, the objective is to minimize the stripping ratio by steepening the slopes to their maximum stable limit. On the other hand, the inclination of working slopes is normally established by operating space requirements and the function of slope mechanics should be the continuous surveillance of slope conditions to assure long-term stability and provide timely warning of impending slides so that corrective measures may be incorporated in production planning. In 1956, Kennecott instituted a program to provide

Jan 1, 1970

By J. C. Mertz

ACCURATE knowledge of the solid solubilities of the elements that dissolve in the important base metals is needed for guidance in the preparation and heat-treatment of the alloys derived from these compo-nents. While there is still difference of opinion concerning the merits of the X-ray and microscopic methods of determining such solubilities, it is certainly true that the recent extensive use of X-ray diffraction to review the existing constitutional data has revealed many glaring inaccu-racies and has brought about a much improved knowledge of phase-boundary locations, which will inevitably come to include all of the important alloy systems. When the work is done with all necessary precautions it appears that in the majority of cases where the solubilities extend beyond a few tenths of a per cent the X-ray back-reflection technique is capable of furnishing the best of information in this field. For the most prolonged and thorough studies it is obviously advisable to combine the results of several methods, in particular, to obtain an agreement between X-ray and microscopic data. This paper reviews the work previously done on the solubilities of phosphorus, arsenic, antimony and bismuth in copper and, in considera-tion of the uncertainties thus made apparent, presents, new X-ray data obtained with the first three members of this group.

Jan 1, 1936