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By H. M. Howe

A Discussion of the paper of Professor Howe, presented at the London Meeting, July, 1906, and printed in Bi-Monthly Bulletin, No. 14, March, 1907, pp. 169 to 274. SECRETARY'S NOTE.-M. Beutter's introductory remarks, being simply a resume of Prof. Howe's paper, with a disclaimer of the intention to criticise it, have been omitted, and the remainder of this contribution has been somewhat condensed, without omitting any essential statements. M. BEUTTER, St. Etienne* (communication to the Secretary-+):-Professor Howe observes in paragraph 47 of his paper that the fluid-compression of steel. diminishes piping by forcing the liquid and viscous metal, while the pipe is forming, or after it has formed, into the space so produced, and proceeds to study the different systems of compression, alluding to the four principal ones: Whitworth, Illingworth, Williams, and Harmet. Having now for many years had in use the last-named process, that of M. Henri Harmet, I shall attempt to explain the difference between it and the three other processes named. The Harmet process does not diminish or close the pipe after it has formed, but prevents it from forming; and I may add that it is the only one of the four which produces this result. It is true that the Whitworth process diminishes the interior hollow by localizing it around the central axis of the ingot, which is afterwards removed by trepanning the hollow forgings for which this process has been, I believe, always exclusively used. The Illingworth and Williams processes, which, in my opinion, are applicable only to small ingots, of necessity allow the pipe to form, or (to use the expression of Professor Howe) they allow the surface of the lake of liquid steel to sink into the interior of the ingot, since they involve waiting a certain time before compression, so that (in the case of the Williams process) the ingot-mold can be opened without dan¬ger, or (in the case of the Illingworth process) so as to avoid the risk that the steel may enter the grooves produced by the removal of the distance-bars. During the time required for

Jul 1, 1907

By K. J. McGrew, J. W. Murphy

Introduction Maximization of profit consistent with environmental protection is the principal goal of new applications development for any conventional or in situ mining technique. Efficient evaluation of all the parameters that contribute to mining costs and production hinges on proper design and evaluation of testing programs and data. The program discussed uses several field and laboratory procedures to estimate ore deposit characteristics and optimize lixiviant compositions. Ore characteristics and lixiviant compositions are then used in a long path leaching test (stream tube test). Stream tube test data are analyzed by mathematical models with computer assistance to predict such wellfield rate parameters as target metal production, lixiviant consumption, and restoration. When these predicted rates are combined with market values for target metals, capital expenditures, prices of lixiviant chemicals, and other economic variables (labor costs, power rates, and licensing fees), an assessment of the relative feasibility of various proposed mining plans is possible. The flowsheet in Fig. 1 illustrates this process. [ ] Field and Laboratory Procedures In general terms, the procedures followed in the evaluation of an in situ leaching application aim at accomplishing: •rapid leaching and maximum recovery of the target metal in a marketable form, •low consumption of lixiviant chemicals, •unquestionably satisfactory restoration of the mined aquifer, and •minimization of capital and operating costs for the above through development of an optimum mine plan. Keeping these goals in mind, the following minimum test program is generally recommended. Geology •Estimate of ore reserves and their variability. •Average disequilibrium value for uranium deposits. •Ore thickness, depth to ore, water level, degree of confinement, and consolidation. •Characterization of quality and quantity of other ore deposit constituents (e.g. sulfide minerals, ion exchange parameters). Hydrology •Single well pump and injectivity test. •Downhole vertical permeability test to compare flow rates of barren and mineralized formations. •Groundwater quality as it may affect licensing, hydro metallurgy, and restoration. Hydrometallurgy • Flask or autoclave tests for optimization of lixiviant parameters and determination of specific reaction rate constants. • Flask or autoclave tests for assessing amenability of lixiviant solutions with ore, consumption of lixiviant, stability of metal in solution contacting ore, and environmentally important species mobilized. • A long-path leach test for modeling the behavior of the lixiviant solution flowing through a long mineralized streamline (stream tube testing). •Metal recovery tests from lixiviant solutions (ion exchange, electrowinning, etc.). •Lixiviant regeneration tests. •Environmental restoration tests.

Jan 1, 1985

November 21st, 1871. THE first session of this meeting was held Tuesday evening, in the chamber of the Common Council, the President, Mr. David Thomas, in the chair. Mayor Carroll, of Troy, gave a cordial welcome to the Institute, which was responded to, on behalf of the Institute, by the first Vice-President, Mr. R. W. Raymond. The Council reported the names proposed for membership with recommendation for election. The following named gentlemen were duly elected Anthony, J., - Williamstown, Pa. Babcock, George, - Troy, N. Y. Blake, Theo. A., - San Francisco, Cal. Blossom, T. M., - New York. Boalt, James A., - San Francisco, Cal. Bowman, Amos, - San Francisco, Cal. Chester, Prof. A. H., - Clinton, N. Y. Dewey, C., - Pittsfield, Mass. Dock, Gilliard, - Shamokin, Pa. Emerson, G. D., - New York. Endres, John J., - Pittsburgh, Pa. Firmstone, Frank, - Easton, Pa. Fowle, W. B., - Philadelphia, Pa. Frazier, Prof. B. W., - Bethlehem, Pa. Gardner, George A., - New York. Goodyear, Watson A., - San Francisco, Cal. Griswold, Chester, - Troy, N. Y. Griswold, J. A.,* - Troy, N. Y. Hague, J. D., - San Francisco, Cal. Hahn, O. H., - Eureka, Nev. Harkness, T. C., - Wilkes-Barre, Pa. Harris, Samuel, - Hudson, N. Y. Henry, E. T., - Oxford, N. J. Holley, A. L., - Brooklyn, N. Y. Howe, H. W., - Troy, N. Y. Hunt, Dr. T. Sterry, - Boston, Mass. Jannet, J., - Troy, N. Y. Knapp, John A., - New York. Laughlin, Henry A., - Pittsburgh, Pa. * Since deceased.

Jan 1, 1873

H. H. Hill.—I believe that as petroleum engineers you are all more or less interested in geophysical prospecting. A large number of the papers that have been written on that subject are too detailed or too much involved to be of much value to a person who is not familiar with the subject, so I suggested to Mr. Fohs that he might bring us something that we could all understand. As I take it, we are interested in learning something about the different methods, the places where they have been used, their limitations and in general whether they have given satisfaction in locating oil deposits. F. J. Fohs, New York, N. Y.—I will briefly summarize some of the results as I Bee them from my practical contacts with them and my discussion of the subject with some of the more important rnen both in this country and Europe. Geophysical Methods 1. Seismographs: A. 1. Sonic refracting seismographs of Karcher, McCullom and Reiber. For rapid reconnaissance and also for detail—perhaps, the best type of instrument. 2. Mechanical refracting seismographs of the Weichert-Mintrop type. B. I. Sonic seismographs using reflected sound from contacts of sufficiently unlike beds where latter are thick enough, being used for detail of both salt domes and ordinary structures where a good reflecting key bed occurs. 2. Torsion Balances: Made in three sizes with greater portability and loss of but 20 per cent. in medium size and loss of 40 per cent. efficiency in smallest size. A. Used to best advantage in detailing salt domes, in noting anomalies of deep-seated structures of the Edgerly, La., type (but not always certain here and dependent on interpretation which involves both experience and the human equation to a large degree). R. Used to advantage in mapping faults where a lime or other denser bed occurs upthrown, and the topographic irregularities are not too involved. C. Of use where buried granite plugs and buried-hill structures occur as in the Western Texas fields. D. Believed of little use for other types of structure. 3. Magnetometers or Variometers: Now built horizontal and vertical with declinometer combined in one instrument. A. Practical in mapping granite or basic igneous rock plugs and intrusions, or of detritus therefrom. Adams has recently demonstrated definite results in mapping the well known Panhandle arch.

Jan 1, 1928

By Edward Steidle

TWO years ago the Committee on Latin American Education Relations, Mineral Industries Education Division, started a study of mineral industries education in the Latin Americas. Information was obtainable only with great difficulty. Some information was available piecemeal but no complete resume had ever been assembled. Initial assistance was gained from the United States Office of Education and the Pan American Union. This, and first-hand knowledge of the writer, provided a list of colleges and universities which were believed to offer work lead. ing to a degree in one or more branches of the mineral industries. Detailed information could be obtained only by direct contact with each university through air mail service. Questionnaire letters were sent to officials of 34 colleges and universities. Twenty-one gracious replies were received. Fourteen of the colleges and universities concerned offer curricula in mining, five in metallurgy, three in petroleum, seven in geology, one in geographical engineering, one in topographical engineering, and one in geophysics. Two institutions offer advanced training in petroleum engineering. No institution offers any courses under the caption of ceramics or fuel technology.

Jan 1, 1945

By A. Kaufmann, B. Cullity, G. Bitsianes

T0 determine the bulk of the phase diagram, techniques for melting, thermal analysis, heat treatment, metallography, and X-ray diffraction that have already been described were used.' It proved difficult to get definitive results for most of the alloy system because of the large number of compounds, their high melting points, and their extreme brittle-ness which made metallography difficult. The final phase diagram, essentially as shown in Fig. 1, was issued with considerable trepidation.' The phase relationships at the two ends of the system were defined with satisfactory accuracy. In the central region between U,Si, and USi, there was great uncertainty concerning the melting points and even the composition of the compounds. At the uranium end of the system, it is quite clear that a eutectic exists at about 985 °C and approximately 8 or 9 atomic pct Si. The a-to-8 transformation is not appreciably altered by silicon, but the 8-to-y transformation is raised to about 795°C. There is appreciable solid solubility in y-uranium, as demonstrated by the micrographs of Fig. 2. The occurrence of the E phase was not suspected at first, since the alloys as melted and furnace cooled gave no X-ray diffraction or thermal arrest indication of it. However, suitable metallography revealed a rim around each of the compound particles as shown in Fig. 3. Heat treatment above 600°C revealed that the rim was another phase which formed by peritectoid reaction between uranium and U,Si,. This reaction proceeds slowly and it is difficult to get it to go to completion. Consequently, there is some uncertainty concerning the exact composition of P and the exact peritectoid temperature. On the basis of various metallurgical studies, it was decided that the most probable composition for t was about 23 atomic pct Si. Metallographic examination shows the closest approach to a single phase at this composition. Likewise, density and hardness measurements of heat-treated alloys shown in Figs. 9 and 10 show a change in slope at 23 pct Si. This is revealed most clearly by plotting the difference in hardness or density between chill-cast and heat- treated alloys as shown in Fig. 4. Zachariasen2 was able to index the diffraction lines of P and to determine the arrangement of the atoms in the unit cell. He concluded that the composition must be US. However, it is felt that the metallurgical studies are reliable and that Zachariasen's X-ray work does not furnish positive proof that the P phase exists exactly at the stoichiometric composition U3Si. There are many instances in alloy systems where a phase does not occur at the composition dictated by the molecular structure. It is possible that the chemical analyses used in the present work were subject to some systematic error. This seems unlikely, however, since recent work in several laboratories seems to show excess compound at 25 atomic pct Si.

Jan 1, 1958

By J. E. Johnson

(Cleveland Meeting, October, 11,1912.) THE subject of blast-furnace slag is one which has had much consideration, particularly from the scientific standpoint, and several years ago technical literature contained many learned discussions on the oxygen-ratio of the acids and the bases, all on the assumption that acids and bases must be present in a ratio depending on molecular weight and chemical valency. Much work has also been done, sometimes in conjunction with the former, on the total heat and the temperature of initial fusion or softening of various slags. A wider knowledge of the blast-furnace now enables us to say that for practical purposes this work has been of almost no value. It is now generally admitted that on the physical side the important point of a given slag is neither its total heat of fusion nor its softening-point, but its free-running temperature, since this is the critical temperature of the furnace. This temperature bears no definite relation to the softening-temperature, as determined by Seger cones, for instance, because some slags melt relatively like ice, with a very short viscous-range, while others melt relatively like tar, with a very long viscous-range. In one the difference between the softening- and the free-running temperature may be very small, as little as 100° F., while in another this difference may easily be 200° or 300°. The importance of this difference is so great in practice as to destroy completely the value of exhaustive investigations, even such as those of 0. Boudouard, published a few years ago.1 * Presented also at the Joint Meeting of the Institute with Section IIIa, Metallurgy and Mining, of the Eighth International Congress of Applied Chemistry, New York, September, 1912. 1 It may not be amiss at this point to call attention to the excellent suggestion of Woolsey McA. Johnson, made several years ago, for determining the temperature at which different slags have the same practical fusibility. This suggestion

Oct 1, 1912

By W. S. Owen, T. Bell

The variation ox the M, temperature with nitrogen concentration has been determined experinzentally. The free-energy difference between martensite and the parent y Phase at the M, temperature,is computed for Fe-C and Fe-N alloys using recent solubility data fm the Fe-N system and new data for the variatim of the activity of the interstitial solute in the y phase with concentration. The "geometric model" is considered also, and the importance of Zener ordering is noted. It is shown that, although at any chosen concentration the M, temperature and the activity are significantly different in the two alloy systems, the free-energy duference is the same within the limits of experimental error, thus Providing further evidence of the very close similarity between the martensite transformations in Fe-C and Fe-N alloys. TO estimate the free-energy change accompanying the martensite transformation in binary interstitial alloys it is necessary to know the variation of the Ms temperature with interstitial solute concentration and some thermodynamic data. To date, only the Fe-C system has been discussed because this was the only system for which relevant experimental measurements had been made, but even in this case the data available are insufficient to permit the free-energy change to be calculated without the assumption of a thermodynamic model for the y and a solid solutions. The last comprehensive discussion of the topic was by Kaufman, Radcliffe, and Cohen in 1.960.' Since that time Ellis, Davidson, and Bodsworth2 have redeter mined the activity of carbon in y iron as a function of carbon content and Atkinson3 has measured the activity of nitrogen in Fe-N austenite. The M, temperature of Fe-N is reported in the present paper. Thus, it is now possible to assess the free-energy change accompanying the martensite transformation in Fe-N alloys on the same basis as that used to assess the change in Fe-C alloys. This comparison is of interest because it has been shown recently4 that the structure of the martensite formed in Fe-N alloys changes with nitrogen content in a manner exactly parallel to the changes in structure in the Fe-C series and that the strain associated with the distortion of the iron lattice in either the y or the a phase by a nitrogen atom is the same as that produced by a carbon atom. The work to be described tests whether or not this close similarity between the two systems extends to the thermodynamics of the martensitic transformations. THE Ms TEMPERATURES FOR Fe-N MARTENSITE Bose and Hawkes5 found the M, temperature of a eutectoid Fe-N alloy (2.35 wt pct N) to be 35°C. This single determination appears to be the only reported measurement of the M, temperature of an Fe-N alloy. In the present work a series of more than fifteen different specimens containing between 0 and 2.7 wt pct N were prepared by controlled nitriding of pure iron wire 0.010 in. diam. The iron was supplied by B.I.S.R.A. and was designated ACN2. The nitriding procedure, all aspects of which are critical, has been described in detail elsewhere.' Each specimen was quenched from the austenitizing temperature into brine at 20°C without removing the specimen from the ammonia-hydrogen atmosphere in which it was ni-trided. Alloys containing up to 0.7 wt pct N were fully martensitic. More concentrated alloys contained progressively more retained austenite. At 2.34 wt pct N the specimen was completely austenitic after quenching to 20°C. The M, temperature of specimens with M, temperature above 20°C (those containing less than 2.35 wt pct N) was determined by a thermal arrest technique. For the more concentrated alloys (2.35 to 2.70 wt pct N) the variation of electrical resistance with temperature down to -196°C was used. Unlike Fe-C alloys, Fe-N alloys cannot be reaus-tenitized in vacuum or in an inert atmosphere because excessive loss of nitrogen occurs, even in short times, at high temperatures. Consequently, the alloys were reaustenitized in the ammonia-hydrogen mixture corresponding to nitrogen equilibrium at the temperatures used. The specimens were quenched in a blast of cold hydrogen gas and the temperature, measured by a thermocouple welded to the 2.5-in.-long specimen, was recorded on a high-speed recorder. In the first experiments 0.002-in.-diam chromel-alumel wire thermocouples were used but it was found that these gave erroneous readings due to contamination by nitrogen pickup. Pt-Pt 13 pct Rh wires of 0.002 in. diam were found to be satisfactory. Further details of the experiments are available in the original thesis.7 The cooling rate was controlled between 400° and 4000°C per sec by adjusting the hydrogen pressure. At least three cooling curves were obtained for each composition. Each specimen was analyzed for nitrogen after quenching. To aid in the accurate location of the martensite arrest points a series of cooling curves of 0.010-in.-diam platinum wire were recorded and these, which did not contain an arrest, were used as comparison standards. Four specimens, each in the form of a 3-in. loop, were prepared from each of the four alloys containing more than 2.35 wt pct N. One specimen was used for nitrogen analysis, one for X-ray diffraction, and two for resistance measurements below 20°C. The latter specimens were quenched from 20°C into constant-temperature baths at selected lower temperatures.

Jan 1, 1968

By L. H. Levenson, Charles S. Barrett

Plastic flow in metal crystals and the changes in orientation resulting from it are generally understood to take place by the following fundamental mechanisms: (1) slip on crystallographic planes, (2) homogeneous crystal rotation resulting from the slip, (3) bending of the 1attice between the planes of slip, and, under certain circumstances, (4) twinning. This paper and a preceding one on iron subjected to uniaxial compression1 concern two additional processes that must now be added to this list: (5) the formation of deformation bands, and (6) the bending and rotation of these bands. The present investigation yields a new understanding and definiteness to the common terms so loosely used when speaking of cold-worked metals —('grain fragmentation," "elongated grains," and "deformation twins," "deformation bands," "etch bands," or "X-bands." Bands have been noted on the polished and etched surfaces of cold-worked metals by various investigators for more than 25 years, ‡ yet their nature and their significance have been so little understood that they are not treated in the most comprehensive modern texts on the deformation of crystals. The experiments in this series show that they are one of the fundamental processes in the deformation of metals, of importance in the development of preferred orientations, in work-hardening (since they have the effect of reducing the effective grain size and interfering with slip), and in the recrystallization process. The present experiments were performed on the same stock of material that was used in the earlier compression experiments1—hydrogen-purified mild steel in which the carbon content had been reduced to the limit detectable under the microscope and in which single crystals could be grown by a strain-anneal treatment.2

Jan 1, 1939

By Charles S. Barrett, L. H. Levenson

Plastic flow in metal crystals and the changes in orientation resulting from it are generally understood to take place by the following fundamental mechanisms: (1) slip on crystallographic planes, (2) homogeneous crystal rotation resulting from the slip, (3) bending of the 1attice between the planes of slip, and, under certain circumstances, (4) twinning. This paper and a preceding one on iron subjected to uniaxial compression1 concern two additional processes that must now be added to this list: (5) the formation of deformation bands, and (6) the bending and rotation of these bands. The present investigation yields a new understanding and definiteness to the common terms so loosely used when speaking of cold-worked metals —('grain fragmentation," "elongated grains," and "deformation twins," "deformation bands," "etch bands," or "X-bands." Bands have been noted on the polished and etched surfaces of cold-worked metals by various investigators for more than 25 years, ‡ yet their nature and their significance have been so little understood that they are not treated in the most comprehensive modern texts on the deformation of crystals. The experiments in this series show that they are one of the fundamental processes in the deformation of metals, of importance in the development of preferred orientations, in work-hardening (since they have the effect of reducing the effective grain size and interfering with slip), and in the recrystallization process. The present experiments were performed on the same stock of material that was used in the earlier compression experiments1—hydrogen-purified mild steel in which the carbon content had been reduced to the limit detectable under the microscope and in which single crystals could be grown by a strain-anneal treatment.2

Jan 1, 1939

By A. T. Yu

Over the last 80 years the conveyor belt has advanced from the troughed rubber belt to those with standard steel cable cores and those which can navigate curves or climb steep inclines. Now the latest generation of belt conveyors can claim hitherto unheard of capacities of 20,000 tph and single flight lengths well exceeding 16,000 feet. The stranded steel cable core belt is principally responsible for the spectacular improvement in load carrying ability of belt conveyors. The allowable working tension of these belts ranges from 2,500 lb per in. of belt width for 1/4 in. diam cable to 4,000 lb per in, for 3/8 in. diam cable. These ratings far exceed the 240 lb per in. per ply for rayon or nylon construction, and 30 lb per in. per ply for a lowcost cotton fabric.

Jan 1, 1970

By L. W. Casteel, E. A. Jones

MINING the lead deposits of Southeast east Missouri has reached a high stage of technical development dictated by the scattered occurrences of low-grade ore through favorable horizons in the Bonne Terre formation. The rock-breaking, handling, and related practices described here have evolved as the best way of mining these particular deposits. These methods are applied in the production of about 19,000 tons of lead ore per operating day from four mines in Southeast Missouri. Development drilling Drifts 10 ft wide and either 8 or 9 ft high are driven in this district on contract. Miners are guaranteed standard wages plus a bonus on the footage advanced, if earned. Labor, fuse, caps, wire, and dynamite used are charged against the contract. Normally the cycle of operations in drifting is performed by a two-man crew, a motor operator and a shovel operator who first load out the rock broken by the preceding shift. The drift crew then sets up two vertical column and mounts the drills. Cleveland HC-10's are used which have a steel lug integral with the cylinder for connection with the air feed. All drilling in drifts is wet. Air pressure is 85 to 100 lb at the face. From 28 to 32 holes are drilled per swing in a pyramid cut. Cut holes

Jan 1, 1947

By C. F. Wang

Page I. Introduction............:.............. 395 Manchuria in General ....................... 395 Pen-hsi-hu............................ 397 Pen-hsi-hu Coal & Iron Co., Ltd................... 399 I1. organization........................... 400 III. Coal Deposit........................... 402 Location..............................402 Geology............................. 403 Coal Mining...........'.................. 404 Mining Methods........................407 Mining Cost.........................408 IV. Coal Washing Plant.......................408 V. Coking Plant..........................410 VI. Iron Deposit...........................413 Magnetite Belt.......................... 413 Origin of Deposit......................... 414 Iron Mining........................... 415 VII. Concentration Plant........................ 417 VIII. Briquetting Plant.......................... 418 IX. Blast-furnace Smelting...................... 418 iNTKODtrCTION Manchuria in General Manchuria. called the "Three Eastern Provinces" in Chinese. forms the northeastern corner of China and is bordered by Siberia on the north and northeast. and by Korea on the east. It is a land famous in Chinese annals as the place of origin of the Ching dynasty. and in more recent times it has bcen an arena for diplomatic maneuvering and commercial competition between the Russians. advancing from the north. and the Japanese from the southeast. It derives its name of "three eastern provinces" from the fact that it is divided into three provinces; Hei-

Jan 1, 1918

By W. L. McMorris, Shiou-Chuan Sun

The Convertol process was first described in Ger- many by Muschenborn1 in 1952. In the U. S. Fraser2 reported this new process in 1953, and Brisse and McMorris-resented the results of a Convertol pilot plant at the Alpheus preparation plant in Gary, W. Va., illustrating the mechanics of the process by a series of sketches. The purpose of the present investigation was threefold: 1) to determine the relative effectiveness of various oils and hydrocarbons for recovering coal by the Convertol process, 2) to ascertain the behavior of coal pulps in this process under various operational conditions, and 3) to compare Convertol with flotation in the recovery of fine coals.

Jan 11, 1959

By George W. Riter

OUR mineral-land laws need revising so as to provide definite title at the outset to the mineral deposits within any definite piece of land. The laws as they now stand, especially those applicable to lodes, breed uncertainty as to rights of possession prior to patent; and to my mind this is the worst feature of all, worse even than the apex bugbear. It is now almost impossible for anybody to tell-with certainty what mineral rights exist within any area that is not covered by patent, or whether any valid rights exist at all. Our system is unique in permitting individuals to appropriate and exploit mineral lands of the public domain without notice of any kind to the Federal government, and to relinquish them without any ceremony at all. The result is a clouded record that cannot be cleared up until each claimant is put to some sort of final proof. In order to accomplish this, new Federal legislation will be required. The requirements for a mineral survey and the proceedings for patent have always been cumbersome and expensive; and perhaps out of regard for the poor claim owner, who can ill afford the outlay for that sort of thing, the law does not require him to go. through it unless he chooses to do so. Consequently, every active mining district has become encumbered with tangled groups of doubtful or conflicting locations, whose rights and boundaries, when any valuable ore is found, must usually be determined by lawsuits that are as expensive and as distressing as the stakes are high. So deeply has litigation entered into our mining system that a claim whose rights have never been disputed would probably be set down offhand, by $miner of the old school, as of no value. Think of the litigation over rights of possession on the Com-stock lode—12 leading companies involved 'in an aggregate of 245 suits within a period of less than eight years! Ambiguous local records; the chance of erroneously placed or obliterated monuments; doubt as to the sufficient performance of the statutory annual labor; uncertainty as to prior conflicting or overlapping locations; anxiety as to the changing attitude of the Department of the Interior and the Forest Service—such considerations as these make an unpatented mining claim an unclean thing in the eyes of possible investors. Is it any wonder that they keep themselvesand their money at a safe distance,

Jan 1, 1915

By S. F. Emmons

[The following notes of observations made during a visit of a few days in the month of October, 1886, which was cut short by a sudden summons East, are offered, in spite of their incomplete and tentative character, in the hope that they may aid the members of the Institute, in their coming visit to this region, to a clearer understanding of the general geological conditions under which the ore-bodies occur.] The Butte mining region lies in a sort of a depression in the mountains which is drained by Silver Bow creek and its various tributaries. On the east it is bounded by high north and south ridges of granite, and on the west by lower ridges, also running north and south, which, as far as examined, were found to consist of rhyolite. High mountains also inclose the depression on the north and south, but at a greater distance than the more immediate bounding ridges on the east and west, the distance between which is hardly more than six miles.

Jan 1, 1888

By R. W. Raymond

There is apparently no end to the doubts, inconsistencies and absurdities in which the courts of our mining States and Territories are involved in their attempts to apply to conditions of ever-increasing complexity the provisions of our anomalous mining law. In previous papers, I have called this statute " the law of the apex," because it based upon that vague, novel and mysterious condition the most important grant of title. But the apex is scarcely a more essential feature than the end-lines and the side-lines; for the rights which it may confer may be limited in various ways by these; so that we have, in many a case, the most ridiculous result that the United States, in return for the money of a citizen, conveys to him with much solemnity, under its broad seal, nobody knows what, bounded nobody can tell how. A decision recently made at Butte by Judge De Wolfe, of the United States District Court of Montana, in the case of King et al. vs. The Amy and Silversmith Mining Company, furnishes a fresh illustration of this criticism. The diagram on the following page, constructed without precise regard to courses and distances, simply to assist in the statement of the essential features of the case, will, 1 hope, make clear the principles . involved : The plaintiff occupies a location (the Nonconsolidated) adjoining on the north the defendant's location, a b c d (the Amy), and the disputed mining-ground lies, let us say, in depth under the point W, that is, on the dip of the vein, VD, but not under the surfacelocation, a b c d. The defendant has the prior title, and claims this ground under its extra-lateral right. It is admitted that the apex does not cross the end-line, a d, and does cross the side-line, a b. Whether it crosses, at the other end of the location, the end-line, b c

Jan 1, 1889

By F. S. Norcross

DEVELOPMENT of the manganese deposits of Cuba is a matter of importance not only to those involved in this industry on the Island but to the United States steel industry and to our Nation as a whole. For years our domestic resources of manganese have been wholly inadequate, but the recent Cuban development points the way toward solution of this strategic mineral problem.

Jan 1, 1939

By J. E. Johnson

The general construction of blast-furnaces has undergone no radical change in more than a generation. When the old style of masonry construction was replaced by the steel shell, the masonry piers were simultaneously replaced by columns, never lese than 6 and frequently 12 or 16 in number, set under the mantle-ring. These columns were at first unvaryingly made of cast-iron, but in more recent years have frequently been made of structural steel. The furnace itself has recently been the subject of radical changes; in some cases the thin-lined construction has been adopted for the whole furnace, and in other cases it has been adopted for a zone immediately above the bosh, raising the mantle several feet to make this possible, but still the style of construction with columns set immediately under the mantle has been universally followed. In spite of the apparent fixity of this type of construction it is open to grave disadvantages from the operating point of view, which may be briefly outlined as follows: The slope of the bosh and size of the crucible are such as to leave scant room inside the columns for the necessary water-piping, etc. The bustle-pipe must necessarily be outside the columns and the penstocks have to pass between them, with the result that the columns are frequently much in the way when changing the tuyeres or otherwise handling the penstocks. Moreover, the hearth-jacket requires a diameter but little smaller than the circle of the inside of the columns, and as a result the cooling-water ditch for protection against breakouts is exceedingly limited in width. As a consequence of these conditions, when any work requires to be done around the furnace, such as changing a tuyere or working on the cooling-water pipes, the amount of room left between the columns, pen-

Jan 1, 1913

By Richard O. Carlson

Ions of p31 and B 11 were implanted in natural insulating diamond macles. The thin (-0.4µ) layers showed sheet resistances of 107 to 1011 ohm per sq and activation energies of 0.17 to 0.34 ev above room temperature. However, no Hall effect could be measured, indicating that mobilities were less than I to 10 sq cm per (v-sec). Such low mobilities may be due to excessive scattering due to radiation damage in the bombarded layer or to very high concentrations of active compensating impurities. Annealing did not materially change the room -temperature properties, but the temperature was limited to -800°C by surface graphitization, the latter process probably being accelerated by lattice damage in our diamonds arising from the ion bombardment. A weak n-type thermoelectric power was detected after p31 irradiation, but it cannot be presumed that we have made the phosphorus ions active as donors in diamond. The natural diamonds have a high and uncontrolled concentration of impurities and, when coupled with the radiation damage and graphitization problems, would appear to seriously limit the quality of semiconductor that we can presently achieve by ion implantation in diamond. ALTHOUGH diamonds are usually thought of as insulating in terms of their electrical conductivity, it was found about 15 years ago that natural semiconducting diamonds do occur rarely, and these were designated as type IIb diamonds. These p-type semiconducting diamonds were found to be dominated by an impurity level 0.37 ev from the valence band. Evidence today based on correlation of the concentration of acceptor states from Hall effect measurements with the impurity concentrations determined by neutron activation analysis point to aluminum as the dominant acceptor impurity.' The compensating donor is believed to be nitrogen, which has a donor level 1.6 ev above the valence band.' However, only a small fraction of the total nitrogen content in the diamond is electrically active. An infrared absorption band at 7.8 p and ultraviolet absorption near 4 ev have been associated with nitrogen, the former providing a quantitative measure of nitrogen content.3 The nitrogen content is -l020 cm-3 in insulating or type I diamonds, but is less than 10'' in natural semiconducting diamonds. Much of this nitrogen is distributed in platelets oriented in (100) planes and not atomically dispersed in the diamond lattice.4 Semiconducting diamonds have been deliberately formed by incorporating impurities into the graphite charge in the high-pressure apparatus used to form diamonds.5 These manufactured semiconducting diamonds are always p-type, and while some show the 0.37 ev level due to aluminum, most such samples have been ascribed to impurity banding effects.6 The best natural or manufactured semiconducting diamonds have hole mobilities near 1500 sq cm per (v-sec) at room temperature, and those with the 0.37-ev level can be analyzed to reveal an acceptor concentration of 3 to 8 X 1016 cm-3 and a donor concentration 3 to 10 times lower.' NO bulk n-type diamonds have ever been reported, but the electron mobility has been measured as 1900 sq cm per (v-sec) by irradiating a diamond with ultraviolet to excite electrons out of the deep nitrogen donor level or other levels.7 New hope for the formation of n-type diamond has emerged from the ion-implantation method whereby desired impurities are introduced into a crystal lattice by bombardment with a high-energy beam of the impurity ion. It was found in the case of silicon that the usual donors such as phosphorus and arsenic and acceptors such as boron and gallium could be implanted into silicon. Wentorf and arrow' produced semiconducting layers on diamonds by an ionic bombardment in a glow discharge at potentials of about 2 kv. The observed typeness from thermoelectric probing seemed to depend on the atmosphere gas (nitrogen, argon, or hydrogen) rather than on the electrode material, but the nature of the conduction process in the thin damaged surface layer is completely unknown. A Russian group under Vavilov has attempted high-energy ion implantation in natural diamonds using boron and lithium ions9 and later also phosphorus, aluminum, and carbon ions.10 Their papers claim n-type layers from lithium, phosphorus, and carbon implant and a p-type layer from boron and aluminum implant, though the methods of type determination are not described in detail. Under government contract support, the Ion Physics Corp. has studied ion implantation in several semiconductors. While the bulk of their study1' was devoted to the irradiation of silicon, they did carry out a short study on boron and phosphorus implantation into natural diamonds. They did observe surface conducting layers but did not determine the typeness of the layers. For our experiments, phosphorus and boron were chosen as the dopant ions because of their respective donor and acceptor behavior in germanium and silicon. Moreover, they are the lightest mass dopants of the shallow level donors and acceptors from columns 111 and V of the Periodic Table (excluding nitrogen which is already present in diamond), and will have the largest depth penetration into the diamond lattice. EXPERIMENTAL Diamonds. As the target diamonds for our ion implantation study, we chose commercially available macles, which are flat, twinned diamond crystals. By scanning through the stock of a wholesale distributor

Jan 1, 1970