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By Herbert Lang

Cord-wood, sawn into blocks of about a foot in length, is a regular constituent of our fuel-charge at Mineral, Idaho, our work being the matting of silver-ores by fusion in a blast-furnace. The furnace is a round water-jacket furnace, of 36 inches diameter at the tuyeres, and the charge of smelting-mixture weighs 950 Ibs., requiring 110 Ibs. of Connellsville coke to drive it. I replace half this coke with 135 lbs. of fir-wood, cut from dead and apparently perfectly dry trees. This mixtrire produces as high a sn~elting-temperature as all coke, whence I infer that the smel ting-effeot of a given weight of wood is to that of the same weight of coke as 11 to 27, or 1 to 25/11. A cord of wood sawed ready for use weighs 2840 lbs., costs $5.00, and is

Jan 1, 1892

By J. E. Pogue

That the domestic consumption of gasoline displays a marked seasonal variation, with a low in the winter and a high in the summer, is well known. It is logical to expect that the nature of the variation has itself been undergoing a change as a result of improvement in roads, general employment of closed cars, and growth of mass haulage; but so far as I am aware the change in seasonal variation has never been investigated and measured. It is the purpose of this paper to present the method and results of such an investigation, undertaken as a contribution to the technique of planning operating schedules now so prominent in connection with the functioning of the industry under a Federal quota system. For the method employed I am indebted to the suggestions and help of Frederick R. Macaulay,1 who kindly looked over the work sheets; and

Jan 1, 1934

By K. J. Anusavice, R. T. DeHoff, H. Oikawa, J. J. Pinajian

STUDIES of nickel self-diffusion and impurity diffusion in pure metals and alloys have, for the past two decades, employed predominantly the nickel radio-However, because of the low energy of the emitted particle, careful and time-consuming techniques must be used to obtain reproducible measurements. In our studies of nickel diffusion into copper, we have recently used Ni66 [Td1/2: 55 hr; : 0.20 Mev (100 pet)] which decays to it much more suitable as a tracer because of the presence of the high-energy y radiation from the cu66 daughter. Although the half-life of Ni66 is appreciably shorter than that of Ni63, the useful working lifetime of a small quantity, " 10 mc, is about 1 month. preparation bf Ni66. he Nis6 radioisotope was produced at Oak Ridge National Laboratory by means of a double (n,y) reaction:

Jan 1, 1969

PERSONAL (Members are urged to send in for this column any notes of interest concerning themselves or their fellow-members.) Members and guests who registered at Institute headquarters during the period June 10 to July 10: J. C. Ralston, Spokane, Wash. E. P. Ashmore, So. Porcupine, Ont., Can. William H. Yeandle, Jr., Mexico City, Stuart Croasdale, Denver, Colo. Mexico. W. E. Hopper, Houghton, Mich. W. C. Minsch, Mexico City, Mexico. D. W. Brunton, Denver, Colo. H. V. Winchell, Minneapolis, Minn. Fred Crabtree, Pittsburg, Pa. W. G. Swart, Denver, Colo. Robert S. Lewis, Salt Lake City, Utah. D. F. Schindler, Madison, Wis. Noel Cunningham, Timmins, Ont., Can E. R. Pettebone has just been elected a Trustee of the Pennsylvania State College, being supported by the votes of the delegates of the Pennsylvania Anthracite Local Section of the Institute and the Engineers' Society of Northeastern Pennsylvania.

Jan 8, 1914

Prof. Dr. H. Seger and Mr. E. Cramer, Chemisches Laboratorium fur Thonindustrie, Berlin, Prussia (communication to the President)* : We have learned, with much interest, from the pamphlet sent to us, of the work of Messrs. Hofman and Demond, particularly as we observe from their experiments that these gentlemen recognize the usefulness of the Seger cones, and that this method of determining temperatures in the furnaces of the ceramic industry and in the tests of refractory clays is valued, not only in all parts of Germany, but also in other countries. Permit us to say, with reference to the crucibles employed in tests for refractoriness, that we have used of late, besides the magnesia crucibles, also those made of Zettlitz kaolin, with the addition of alumina, previously calcined, with regard to which we beg to refer to our article in the Thonindustrie-Zeitung of December 9, 1893.

Jan 1, 1895

By R. L. Tobie

Handling and storing ore at transfer points underground are encountered frequently. An ideal solution to these troubles is probably still to be found, but at the Mather mine "B" shaft a method incorporating scraping trenches has been developed giving better service, from the standpoint of safety and simplicity, than obtained from other schemes. When shaft pockets are used for storage, the size of the ground opening required to assure capacity is often prohibitive, and shaft depth below the last level can become excessive, particularly if a crushing station is used. Also, if the material being handled contains large amounts of wet fines, it is difficult, if not impossible, to hold the material with regular chute gates. In order to remedy these problems Cleveland-Cliffs' Mather "B" has utilized three types of trenches. Types I and I1 are now in service and the third is under construction.

Jan 4, 1955

By Michael Richings

Although the role of slope stability has not changed, there have been changes in the mining industry which affect the geotechnician engaged in slope stability studies. The deposits currently being mined or evaluated are technically difficult , capital intensive, and economically marginal. In addition, many mining companies are now either controlled by oil companies or are financing projects through bank loans. The mining investor or decision maker is, therefore, often more sophisticated financially, but less sophisticated in mining terms. The impact of these changes will be to force the geo- technician and mining engineer to attempt to quantify risk and financial implications of a slope design. In conclusion, this paper outlines several questions which mining engineers should be asking those engaged in geotechnical studies and indicates the necessity for the mining engineer and geotechnician to work together and quantify the financial risk associated with a geotechnical design.

Jan 1, 1983

No. 219. Assayer for gold-silver property in Ecuador. No. 220. Two engineers to go to Russia, 22-28 years old. Not engaged or married. Knowledge of some language other than English. To study conditions in Russia two summers and intervening winter. One man must have experience in oil-well operation or oil manufacture; the other, in mining or metallurgy. Salary £300 per annum, plus traveling and living expenses. No. 221. Position in metallurgical testing department. Initial salary $1600 to $1500. Candidate who has had industrial training and experience either in the manufacture and testing of steel or in electro- metallurgy preferred, but one who has had post graduate work in these lines will be considered. No. 223. Experimental and research laboratory in Wisconsin wants ,a man who has had experience in ore dressing, iron ore preferably. Salary $3600. Also, an iron metallurgist. Salary $3600.

Jan 7, 1917

By H. E. Howe, A. A. Smith

E. Schumacher.*—Mr. Smith has shown us once again how variable lead alloys can be. I have studied lead alloys for a good many years and know from experience that their behavior cannot be predicted by analogy with other alloys. I have always been interested in observing how the creep resistance of lead may be improved by the addition of as little as 0.03 per cent Ca. Without the presence of calcium the grains of extruded lead pipe are fairly equiaxed and motion can take place easily at the boundaries. The calcium addition of 0.03 per cent causes the grain boundaries to become very irregular and jagged, and results in creep resistance many times greater than that of pure lead. Mr. Smith showed that in the one per cent antimony-lead alloy creep is occasionally excessive even where low stresses are involved. We have observed this phenomenon many

Jan 1, 1945

By B. Wilshire, W. J. Evans

The high-temperature creep properties of nickel, zinc, and iron have been determined over a range of stresses. The creep strain, E, was found to vary with time, t, as: where e0 is the instantaneous strain on loading, ET the total transient creep strain, $ the steady creep rate, and m is a constant relating to the rate of exhaustion of transient creep. Deviations from this relationship occurred during the initial 10 to 15 pct of the transient stage. These deviations result in the initial creep rate, go, calculated as (m . ET + es), being considerably lower than those obtained by measurements on the creep curve. For all materials, the initial creep rate, the constant m, and the duration of transient creep are all related to the steady creep rate. These relationships suggest that transient and steady-state creep should not be regarded as distinct stages.

Jan 1, 1969

G. SHERBURNE ROGERS,* Washington, D. C. (written discussion ?).- Mr. Neal's paper on the petroleum hydrology of the Mid-Continent district is a welcome contribution on a subject concerning which none too much is known; it is, I think, the first published description of the chemical character of the oil-field waters of the great Mid-Continent area. When studying the oil-field waters of the California fields several years ago, the differences in chemical composition between waters occurring at various horizons seemed to be sufficient to enable the operators to use water analyses as a basis for determining the source of the water flooding a well; and it is gratifying to find that, Mr. Neal has arrived at a similar conclusion. As Mr. Neal points out, the Mid-Continent waters are very different in character from those of the California fields, and casual. inspection

Jan 3, 1919

By Terry G. Richard, Sunder H. Advani

A sequence of 250 unconfined compression tests were completed on a common marine shale indicative of the overburden strata of east- central Ohio. The samples were of a light gray clay shale of Pennsylvanian age. The shales considered are obvious layered materials with distinct bedding planes. For this reason there is sufficient evidence to consider this material as anisotropic in nature. With a properly chosen reference coordinate system this anisotropy can be reduced to a layered orthotropic characterization. This implies that the mechanical properties can be specified with regard to principal material directions. With this nature in mind a systematic study of the combined influences of strain rate and moisture conditioning was initiated. Of particular interest is the variations in unconfined ultimate compressive strength with variations in the controlled parameters of strain rate, moisture conditioning level and direction of testing. Results of this particular phase of the program are presented.

Jan 1, 1982

By Roger N. Dokken

It is well-known1-4 that Fe-Si alloys from approximately 9 to 27 at. pct Si show an ordered structure of the Fe3Si type at room temperature. Recently Meinhardt and Krisement,' through an investigation of Fe-Si alloys at room temperature by neutron diffraction, discovered that at 10.8 at. pct Si ordering of the FeSi type occurs while above this composition the normal Fe3Si-type superstructure appears. This FeSi type of ordering was also found by Davies8 as indicated by X-ray diffraction measurements on an Fe-8.7 at. pct Si alloy. Meinhardt and Krisement7 extended their neutron-diffraction work and determined the phase-boundary temperatures for both FeSi- and Fe3Si-type ordering. Ordering phenomena can also be studied by resistance measurements.4,8-11 Krivoglas and Maty-sina" carried out a theoretical development of the

Jan 1, 1965

By Robert T. Walker

Robert T. Walker and Woodville J. Walker (Walker Engineering Corp., Salt Lake City)-Mr. Kinkel's article embodies, in condensed form, the results of the first detailed and complete geological survey that has ever been made of the long neglected but potentially very important West Shasta Copper-Zinc district, in Shasta County, California. In view of the difficulties of the terrain and the complexity of the geological structure, this represents a notable achievement, and it is with regret, therefore, that the writers find it necessary to differ from Mr. Kinkel's conclusions on two important points. The first has to do with the interpretation of two members of the stratigraphic column of formations in the district; for purposes of comparison, the description of these two members according to Mr. Kinkel is shown parallel to the description of these members according to the writers, see Fig. 14, Mr. Kinkel's nomenclature being used

Mar 1, 1956

By G. W. P. Rengstorff, L. E. Olds

PREVIOUS research has shown that cast molyb-denum has good ductility at room temperature if the metal is sufficiently pure. In practice, however, it is very difficult to reduce the impurity content of molybdenum to a few parts per million—the maximum content of impurities allowable to obtain reasonable ductility in coarse-grained molybdenum. Also, subsequent fabrication may reintroduce enough impurity to damage ductility greatly, unless extreme precautions are taken to protect the metal during working. The major impurities which embrittle molybdenum are oxygen, nitrogen and, to a lesser degree, carbon. It is reasonable to assume that the harmful effects of such impurities might be neutralized by small amounts of alloying additions. The desired alloying elements would be those which might fonn stable metal oxides or nitrides that would not be harmful to ductility, or thosewhich might increase the tolerance of molybdenum for oxygen and nitro-

Jan 1, 1958

By R. L. Curfman

WHEN the Uranium Reduction Co. mill was put on stream in October 1956, one of the many operational problems was that the sand-slime separation circuits could not produce a satisfactory RIP feed, inasmuch as production greatly exceeded de- sign capacity. The original cyclone portion of the circuits consisted of two stages of three 14-in. cyclones in each circuit, as shown in the condensed flowsheet. The high percentage of +325 mesh material in the over- flows of these 14-in. cyclones was not consistent with good operation, and flow rates per ton of ore were high, indicating that not enough of the total solids in the ore was being rejected as sands. It was inferred by members of the metallurgical department that returning the underflows, or sand fraction, from these cyclones back into the drag classifiers was the primary reason for dirty feed.

Jan 7, 1958

By Paul A. Hodges

With plant start-up slated for early 1966, Palabora Mining Co. will take its place among the large copper mining properties of the World. Located near the town of Phalaborwa in the Lowveld area of Transvaal Province, approximately 250 air miles northeast of Johannesburg, Palabora is the result of a cooperative project between Rio Tinto-Zinc Corp. and Newmont Mining Co. Other large shareholders are American Metal Climax, Inc., Union Corp. Ltd., and Selection Trust Ltd. Earliest known mining activity in the area is thought to date back about 400 years, when the Bantu tribes were migrating southward from the great lakes of Central Africa. Old workings and hand tools have been found in numerous places on the flanks of Loolekop, the hill that contains the outcrop of the Palabora orebody. Nearby ruins of small furnaces give added evidence of the knowledge of copper smelting possessed by these natives.

Jan 3, 1966

More than 400 members and guests registered for the 146th General Meeting of the Institute held in Mexico City Nov. 9 to 15, inclusive. Of these, 250 came by special train or automobile from 24 states of the Union, and the others were resident in Mexico. Mexican Government officials, headed by Manuel Santillan, Sub- secretary of the Department of National Economy, acting in. behalf of the President of the Republic, and including the Secretary of Foreign Relations and the Governor of the Federal District, were most hospitable in their official welcome and provided splendid entertainment of various kinds. A reception was tendered by Hon. Josephus Daniels at the U. S. Embassy. Among other hosts were officials of a number of large operating companies, including M. H. Kuryla, of the Real del Monte company; Jules Lacaud, of the CompaiLia Minera de Chontalpan; and Harry Wright, of the Consolidated Steel company.

Jan 1, 1937

By M. T. Simnad, C. E. Birchenall, M. H. Davies

THE marker movements observed by Davies, Simnad, and Birchenall during the growth of magnetite on wustite have been misinterpreted. It is the purpose of this note to correct the original interpretation. In that investigation wustite specimens were prepared by oxidizing pure iron disks in water vapor until the iron was consumed. Argon was used as a carrier gas for the water vapor and on the complete conversion of the metal to its oxides ('FeO' plus a small amount (10 pct) of surface Fe3O) the water supply was bypassed and the specimens were annealed in argon alone in order to equilibrate the wustite with the overlying magnetite. After cooling, the magnetite was ground off, a crude magnetic test being employed to determine its complete removal. Radioactive silver streaks were then applied to the surface and the specimen was oxidized completely in water vapor to prevent hematite formation. After complete oxidation the markers were found to enclose about 80 pct of the magnetite with the other 20 pct lying outside the markers. This observation was interpreted to mean that oxygen transport was four times as great as iron transport during the growth of the magnetite. The conclusion would have been correct if, as in the case of wustite growing on iron, all the iron had started from one side of the marker and all the oxygen from the other side initially. Actually a material balance is required. For simplicity, take wustite to be exactly FeO, and magnetite to be Fe3O,. Then at the start of the reaction 3 FeO + O -> Fe,O., All of the iron and three-fourths of the oxygen of the final product will be within the marker inter- faces. The other fourth of the oxygen is in the gas phase outside the marker. From the experimentally determined final position of the markers simple calculation shows that one-fifth of the total iron has crossed the marker interface, while one-twentieth of the total oxygen has crossed in the reverse direction. The simplified result favors iron transport in the ratio four to one. However wiistite is not stoichiometric FeO. At 900°C, the temperature of the measurement, the composition is about FeO When the material balance for the same experimental result is repeated, assuming the product will be 1 mol of Fe3O4, it is found that 0.6 gram atoms of iron and 0.19 gram atoms of oxygen must have passed the marker in the same direction. (This is readily apparent from the reaction to form 1 mol of Fe3O4 SFeO The total oxygen supplied from the atmosphere is 0.61 gram atoms, but the iron which passes the marker interface, i.e., 0.6 gram atoms, requires 0.8 gram atoms of oxygen to convert it to Fe,O,.) If all the transport during magnetite growth is due to iron ion diffusion, then the marker would enclose about 85 pct of the final magnetite and the original measurement is in error by about 5 pct. This error is probably less than the uncertainty in locating the markers by autoradiography. The possibility also exists that the starting wustite was not quite saturated with oxygen and underwent further enrichment with consequent envelopment of the marker before magnetite caught up with the marker interface. In any case it appears that these measurements actually favor iron ion diffusion in magnetite overwhelmingly as the factor controlling its growth, although further experimental measurements are needed to eliminate the error in material balance described. Such studies are planned.

Jan 1, 1954

By Ed L. Reed

INTRODUCTION The most efficient development of a mine plan for in-situ leach (solution) mining must be based upon an understanding and application of the basic hydrologic characteristics of the aquifer containing the mineral values. Similar knowledge of the overlying and underlying aquifers is also required. This paper summarizes the hydrologic properties of a ground water system and describes some of the more important conclusions that can be drawn from a detailed hydrologic study. Basic to an in-situ leach mining operation is the flow of fluids through porous rock from place to place. The degree to which these movements of fluids can be predicted and controlled determines to a large extent the efficiency of the ore recovery operation. HYDROLOGIC CHARACTERISTICS The principal hydrologic characteristics of a porous medium (sand, intercrystalline or vuggy limestone, fractured basalt, etc.) influencing fluid flow are: Porosity Permeability Thickness Transmissivity Storage Coefficient Water Table or Piezometric Surface Hydraulic Gradient Briefly these parameters can be defined as follows: Porosity: the void space in a unit volume of rock. Permeability: the ease with which fluid will flow through a porous medium. Thickness: the height of the formation which contributes flow to a well. Transmissivity the product of permeability and thickness. Storage Coefficient. the volume of water released from the reservoir per unit drop in head. Water Table or Piezometric Surface: the level at which water will stand in a well: the top of the zone of saturation in a gravity aquifer; the height to which water will rise above the confining bed in an artesian system. Hydraulic Gradient the direction and rate of dip of the water table or piezometric surface. A properly designed pumping test will provide numbers for transmissivity, storage coefficient and the water table or piezometric surface. Drilling records or bore hole logs provide aquifer thickness data from which permeability can be calculated. Ground elevations applied to measured depths to water enable one to calculate the direction and rate of dip of the water table or piezometric surface. Porosity can be determined from core analyses or density logs; it can be estimated from grain size distribution curves in sands or sandstones and from, microscopic examination of drill cuttings derived from carbonate aquifers. CHARACTERISTICS OF FLUID FLOW The characteristics of fluid flow that are vital to an understanding of leach mining include: Velocity Direction Flow Path Radius of Influence The velocity of fluid flow is of paramount importance in planning and managing a leach mine operation. Velocity is directly proportional to the permeability and hydraulic gradient and indirectly proportional to the effective porosity The permeability determined from a pumping test is an average value for the interval stressed; therefore, the velocity calculated from data derived from a pumping test represents average conditions. Under actual conditions discrete portions of the aquifer open to the screen may have permeabilities several times as high as the average and minimum permeabilities only a fraction as much. An injection front will be irregular to the extent that the reservoir rocks are heterogeneous An important consideration is the direct relationship of velocity to head. A reservoir which would provide a velocity of 0.05 feet per day under conditions of equilibrium would allow fluid flow of 36 feet per day under typical leaching operations, i.e. 12-foot injection head, 12-foot pumping level and 50 foot five-spot pattern. The direction of fluid flow is also vital both inside and outside the mine area. In the pattern area the direction of flow is determined by the geometry of the well field and can be approximated by mathematical modeling techniques. Outside the well field, the direction of flow is influenced by both natural conditions and the degree to which production and injection volumes are balanced. Flow directions (and velocities) are critical to an understanding of leachate excursions and their control.

Jan 1, 1979