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By Charles White Merrill

Mankind's progress is measured in minerals. Man's emergence from prehistory is marked by passage through a Stone Age and a Bronze Age and into the present era, sometimes called the Iron Age or the Age of Metals. With the evolution of civilization and the development of a modem industrial economy, minerals become more and more important. Structures, roads, and machines are built largely of minerals; the energy to heat the structures and to drive the machines is mostly mineral; agricultural fertility is maintained by mineral fertilizers and water; and military strength is provided by fortresses, armaments, and munitions, largely of mineral origin. Thus in the material world, in the productivity of the economy, access to minerals has paramount importance. Every evidence indicates increasing dependence on minerals in the modem economy, particularly on the mineral fuels as energy sources to provide the power base for advancing industrialization. Both the total and the per capita consumption of almost every mineral is increasing in the industrialized nations. Moreover, nations with predominantly agrarian economies call themselves underdeveloped and universally strive to industrialize. Most mineral consumption trends in the more advanced economies have been greatly exceeding population growth-which itself has been advancing at an accelerating rate-and sometimes have surpassed the growth in real income. Some minerals have only recently been adopted or grown to importance in use. Titanium metal did not appear as a commercial product until 1948, and even coal seriously displaced wood as a source of heat less than two centuries ago. On the other hand, minerals have always played an important role in construction. The prehistoric megaliths that form the dolmens of Salisbury Plain are stone; the pyramids are andesite faced with limestone; and many other ancient structures are built of mineral materials. In modem times the whole course of architecture has been redirected by new building materials, mostly mineral. Most conspicuous is the sky-

Jan 1, 1964

By C. R. Van Hise

Introduction.............29 The Three Zones of the Lithosphere ..30 Zone of fracture............31 Zone of flowage............ 31 Factors influencing depth at which flowage occurs.. 32 Zone of combined fracture and flowage.. 33 The Water-Content and Openings in Rocks....36 Condition of rater in the zone of fracture.. 36 The openings in rocks...........38 Size and number of openings..... 40 Ore-deposits derived from zone of fracture..45 The source of underground water......... . 47 The cause of the flowage of underground water..47 Belts of underground circulation.. 51 Upper belt of underground circulation.. 51 Lower belt of underground circulation.. .... .52 Capacity of water for work in the lower belt of underground circulation........... 53 Movementsof water in the lower belt of underground circulation. 54 The preferential use by water of large channels.. 60 Physico-Chemical Principles Controlling the Work of Under ground Waters..........62 Chemical action............63 Underground aqueous solutions..64 The relations of solution and temperature..... 65 The relations of solution and pressure..66 Precipitation........... 67 Precipitation by change in temperature..68 Precipitation by change in pressure..69 Precipitation by reactions between aqueous solutions.. . 69 Precipitation by reactions between liquid solutions and solids. 70 Precipitation by reactions between gases and solutions. and solids............71 The General Geological work of Underground Waters.. . 71 Division of the zone of fracture into a belt of weathering and a belt of cementation............72

Jan 1, 1901

By John Greenawalt

IN view of the increasing importance of sintering in the beneficiation of iron ores preparatory to their reduction in the blast furnace, the writer believes the time is opportune for an up-to-date, though brief, discussion of the general principles of sintering, as well as a discussion of some of the recent improvements and mechanical developments that have been achieved in this industry, its present trend and future possibilities. Sintering may be defined as the agglomeration of fine mineral particles into a porous mass by incipient fusion caused by heat produced by com-bustion within the mass itself. Its first successful application, in connec-tion with the treatment of lead sulphide ores, was known as blast roasting. In this process the lead ore was given a preliminary roasting in a reverber-atory furnace, then the incandescent mass was placed in a pot with a grate and an updraft was applied. It was soon discovered that much better results were obtained by cooling the ore, moistening it, and placing it upon an incandescent layer of fuel previously placed upon a grate, and then applying the updraft blast of air until the charge was converted into a more or less agglomerated mass. The fuel was sulphur and the process one of desulphurization, which was the principal result desired. The application of downdraft to blast roasting brought about tremen-dous results; the principal one of which was that an air blast of high pressure could be passed through a layer of ore deposited on a grate, or on a grate covered by a layer of coarse porous material, without disturbing the particles of which the layer is composed. The air current is compelled to filter through the pores of the charge, whereas if the same pressure applied to the top surface of the charge with downdraft were applied to the bottom of the charge with updraft, the charge would be completely blown off the grate. Another result of reversing the draft was that a flame could readily be applied to the top surface of the charge for ignit-ing purposes.

Jan 1, 1938

By Albert J. Phillips

The effect of impurities on the flowsheet in the smelting and refining circuits for copper, lead and zinc is reviewed and the interflow of by-poduct metals from copper, lead and zinc plants is pointed out. The principal points of separation of all impurities in the circuits are indicated and the additional steps added to these circuits in order to effect impurity separation me shown. In this day and age, when difficult metallurgy is mentioned, one thinks of the extraction of more refractory or possibly the alkaline earth or rare-earth metals. It is true that the extraction of metals having a high affinity for oxygen and deleterious solubility for that element in the liquid metal, affords some of the most difficult extractive metallurgy problems. When this is coupled with an affinity for hydrogen, nitrogen, and carbon a devious approach is required that sometimes rivals the complexity of the metallurgy with which this paper deals. However, in all such cases the aim is for a simple

Jan 1, 1962

By J. D. Lubahn

Prior tests by Dorn, where the strain rate in a tensile test was suddenly changed, have shown a small, but definite rate-history effect to exist. If this effect is neglected in the calculation of creep behavior from tensile results, an error should occur. This paper shows that this error is smaller than experimental scattering, and may be neglected. DORN1 has found a small but definite rate-history effect in the aluminum alloy 250 at liquid-nitrogen temperature using tensile tests with an abrupt rate change. Such an effect is to be expected from pre-viously known2-6 temperature-history effects, together with general experience that effects produced by changing the strain rate a large amount are simi-

Jan 1, 1959

Meeting, June 26, 1913).-On the petition of 29 members residing in and near San Francisco, Cal., the San Francisco Local Section was established. The territory of the St. Louis Local Section was established to include the following States and parts thereof: All the State of Missouri ; That part of the State of Illinois south of and including the city of Urbana ; That part of the State of Indiana south of and including the city of Indianapolis ; That. part of the State of Kentucky west of and including the city of Frankfort ; That part Of the State of Tennessee west of and including the city of Nashville That part of the State of Arkansas north of and including the city of Little Rock.

Jan 7, 1913

The program of 'the Chicago meeting, which is to be held Sept. 22-26, is as follows: Monday. Morning-Registration. Afternoon-Technical Session. Evening Smoker. Tuesday. Morning and Afternoon-Excursion by boat to Gary and trip, through United States Steel Co's. plant. Evening-Technical Session. Wednesday. Morning- Technical Session. Afternoon-Technical Session. Evening-Banquet, Congress Hotel. Thursday. Morning and Afternoon-Special train to La Salle and De Pue, Ill., Inspection of Zinc Smelters, Cement Works, and Coal Mines. Trip to Starved Rock and points of historical interest. Evening-Return by train to Chicago. Friday. Morning-Optional trips. 1. East Chicago Metallurgical Plants and Oil Refineries at Whiting, Ind. 2. North Chicago and Milwaukee. 3. Local Chicago Plants. 4. Coal trip to Franklin and McCoupin Counties.

Jan 6, 1919

Apr. 26-May 11, Liege International Fair, Liege, Belgium. May 4-8, Electrochemical Society, Inc., Spring meeting, Benjamin Franklin Hotel, Philadelphia. May 5-6, National Air Pollution Symposium, Huntington Hotel, Pasadena. May 5-7, American. Mining Congress, coal convention, Netherland Plaza Hotel, Cincinnati. May 6-9, Scientific Apparatus Makers Assn., annual meeting, Edgewater Beach Hotel, Chicago. May 9-10, AIME, joint meeting, Industrial Minerals Div. and Metals Branch, Davenport Hotel, Spokane, Wash. May 11-14, American Institute of Chemical Engineers, Atlanta Biltmore Hotel, Atlanta. May 17, AIME, Chicago Section, President's night dinner dance, Shoreland Hotel, Chicago. May 27, AIME, Morenci Subsection, Longfellow Inn, Morenci, Ariz. June 2-4, Chemical Institute of Canada, annual conference, Montreal. June 4-14, Mechanical Handling Exhibition and Convention, Olympia, London.

Jan 1, 1952

By W. E. Field

In the Coast Mountains approximately 110 miles north of Vancouver, the gold mine of Bralorne- Pioneer Mines Ltd. lies at an elevation of 3500 ft. The deepest or 41 level in the mine is at an elevation of 1400 ft below sea level, and the rock temperature on this level is 122.5°F. The thermal gradient is 1 "F increase in temperature for each 67.5 ft increase in depth. The mine produces between 500 and 600 tons per clay, utilizing an adit two internal shafts, and one service shaft from surface. The Queen shaft, extending from the 26 to the 41 level, IS the deepest, and most production now comes from this area. Stoping in by cut and fill using mill tailing hydraulic backfill.

Jan 12, 1963

By E. H. Wells, A. Andreas

Greater progress than in any previous year was accomplished by the oil industry in New Mexico in 1936. The total number of completions in the state was 631, of which 549 were oil wells, 21 were hydrocarbon gas wells, three were carbon dioxide gas wells, and 58 were dry holes. The total oil production for the year was 26,804,446 bbl. Compared with the production for 1935 of 20,228,947 bbl., this represented a gain of 32.5 per cent. Of the total production, 25,337,382 bbl. came from Lea County. The average daily nonmarginal well allowable for that county was 115 bbl. the first of the year and 86 bbl. at the close. Production was regulated by the New Mexico Oil Conservation Commission,

Jan 1, 1937

By Howard Eavenson

THE low-volatile, or smokeless, coal field of southern West Virginia is in Fayette, Raleigh, Wyoming, Mercer, Summers and McDowell counties, in the extreme southern portion of the state, and extends into the adjacent counties of Tazewell and Buchanan in Virginia. McDowell County is the largest producer, with Fayette and Raleigh counties next. The total area of the field (Fig. 1) is approximately 1600 square miles, or 1,024,000 acres. The percentage of volatile matter in the various seams ranges from 15 to 26 per cent. The upper limit of true low-volatile coal is usually considered to be 23 per cent volatile matter; above this point, the coal usually is classed as medium volatile. This limit will be used in this paper.

Jan 1, 1931

CONTENTS PAGE Simons, Theodore.-Basic Principles of Gravity Concentration-A Mathematical Study : :.. 1 Taggart, Arthur F. and Gaudin, A. M.-Surface Tension and Adsorption Phenomena in Flotation 11 Hersam, Ernest A.-Factors Controlling the Capacity of Rock Crushers 12 Shaw, S. F.-The Ore Deposits of Sierra Mojada, Coahuila, Mexico 12 Wilson, Philip D.-The British Columbia Batholith and Related Ore Deposits 26 Greensfelder, N. S.-Shot-firing by Electricity 27 Mitke, Chas. A.-Metal Mine Ventilation in the Southwest 28 Foley, F. B. and Howell, S. P.-Neumann Bands as Evidence of Action of Explosives upon Metals 30 Schwartz, H. A., Payne, H. R., Gorton, A. F., and Austin, M. M.-Conditions of Stable Equilibrium in Iron-carbon Alloys 30

Jan 12, 1922

By Gustav Egloff

AN unexpected and unprecedented demand for its products now challenges the petroleum industry. Between 1939 wand 1946, domestic oil demand increased nearly 45 per cent and in the first half of 1947 it was 10 per cent higher than in 1946. In 1939 the United States produced 1,264,962. 000 bbl of crude oil and indications are that about 1,860,000,000 bbl will be produced in 1947, a 47 per cent increase. Runs to stills are more than keeping pace with production. The crude capacity of 365 operating refineries is rated as 5,400.000 bbl daily and almost 100 per cent of this capacity was running crude oil in August 1947. The oil industry is cognizant of our need for a greater volume of petroleum products and is expending the huge stun of four billion dollars on exploration. production. transportation, refining. and marketing of petroleum. Of this amount about half will be spent on exploration and production. a billion on refining. and another billion on transportation and marketing facilities.

Jan 1, 1947

By James Hyslop

MECHANIZATION of American coal mining continues to make rapid progress. Economic pressure will compel abandonment of manual methods wherever possible and will also provide the incentive needed for the improvement of machines and mining systems. However, rapid progress may be made along strictly technological lines and at the same time much slower progress in approaching maximum productivly and efficiency. One can well ask, just how efficient are mechanized mines, and to what extent is productivity affected by the mental attitude of management and workers?

Jan 1, 1946

By H. Foster Bain

Jan 1, 1910

By Betty L. Gibbs

A company must have an organized approach to effectively sort through the profusion of available software and hardware and find the programs and equipment which fit defined needs. The selection process must build a complete compatible system which includes hardware and software. The methodology presented in this paper helps identify some of the more important considerations. The steps needed for an organized approach to software/hardware selection are: •All involved staff should contribute to an assessment of current computer capabilities and projection of future needs. •Alternatives are analyzed to determine what software and hardware is available and how selections may possibly be merged into the existing computer system. The evaluation process focuses on details of program capability and hardware compatibility. Analysis must be done to determine how closely individual programs fit the established requirements. The final decision is often a balance of needs between program capabilities and hardware availability. Any programs selected must be able to run on existing and newly purchased hardware. Any additional hardware selected must be capable of meshing with the available computer system.

Jan 1, 1983

By R. J. Corfield

MODERNIZATION of the entire electrical system and improvement of Rotation process efficiency is the twofold goal of the improvement program underway at the Arthur and Magna concentrators of the Utah Copper Div., Kennecott Copper Corp. Copper ore from the Bingham pit goes to these two concentrators where an interlocking program calls for complete electrical modernization and increased flotation process efficiency through additional capacity and flow scheme revisions. Flotation plants at the two mills are essentially duplicates, and while this article deals with the changes at the Arthur mill similiar improvements are being made at the Magna mill.

Jan 3, 1953

George E. Collins, Nacoochee, Ga. (communication to the Secretary): The results tabulated below were obtained at the Reynolds mill, White county, Ga. They were noted, not with a view to investigating the point discussed by Mr. Clark, but in course of a test on a working scale to determine the com parative saving from a given free-milling ore on copper and silvered plates respectively. In every case the bullion assayed was the result of a separate clean-up on a considerable quantity of ore. The ore varied widely in grade and in other respects, but the runs bracketed in the table were made at the same time, in adjoining batteries, and on similar types of ore. In a * Result modified by the addition to the bullion-shipment of a little impure bullion left over from previous clean-ups.. On these occasions, the strips of copper were removed from the tables, and: their lower surfaces were cleaned. Hence the higher yield reported.

Jan 1, 1900

By M. S. Azun

I do not at all agree with the basic points of the author's conclusion. The use of lognormal or normal model to respond to the attribute distribution function should be carefully questioned. If fitting a distribution function of regionalized variables is the main purpose, one may employ one of certain well-known families of distributions, such as Tukey's lambda functions. For instance, the distribution function of gold assay values studied by Krige (Krige, 1978) may fit the lognormal model well, but one should not exclude that the basic idea of using the distribution function of observed data is to have insight of the physical mechanism that gives rise to the regionalized variables. In Applied Geostatistics, there are many examples considering only lognormal or normal model for the distribution function of geostatistical data even if the observed distribution function has more than one mode. Of course, using lognormal or normal model always brings easy computation for the statistical properties of attribute under investigation. Still, I object to adopting any of those models without having any "statistical inference." As seen from the author's paper, lognormal and normal model produce the same average grade (0.746% copper) and almost the same sample variance. Therefore, which model explains the probabilistic behavior of ore deposit is always an important question that should be replied by the geostatistician using not the common sense but the statistical and probabilistic methods. For kriging procedures, such as linear kriging, one should describe either second order stationary properties or bivariate properties of regionalized variables. Second order properties, such as correlogram function or semivariogram function, are the inputs of the so-called kriging equations. Selecting one of any useable models for the observed second order properties, such as spherical model, is not easy since the models are not based on the correlations structure of the regionalized variables. How those models being used in Applied Geostatistics can be distinguished is another important problem. One may develop many fitting models to respond to the observed second order properties of regionalized variables. However, I suggest that the model should be based on the probabilistic behavior of geologic process. The author used spherical model for copper, wolfram, and silver grades from isotropic sector (Fig. 2, 4, 3b) and exponential model for silver grades obtained along raises in isotropic sector (Fig. 3a). It seems that those semivariograms given in Fig. 3b for isotropic sector and Fig. 4 may be described by the random model implying that regionalized variables do belong to renewal process (Azun, 1983). If I knew the total number of data points used in estimation, may prove that my conclusion is correct. Recalling the test for the first order sample correlogram value, the test procedure is introduced such that the independence is rejected if [Ir(1) I > Za/2 N1/2] where Za/2 is the a/2 percentile of standard normal random variable and N is the total number of samples used in estimation (Azun, 1983). For the other observed semivariogram functions I suggest the author might try to use the so-called "Markovian model" describing not only the correlation structure of regionalized variables, but also the physical mechanism that produces the regionalized variables. The Markovian model for correlogram function is, [p (h) = T 1ih , h>1 ,] The Markovian model for the other second order properties of ReV are also derived. [T veß], in the above equation, show, for example, structural change and mineralizational variation in a considered deposit, respectively (Azun, 1983). In selecting any model, it is not easy to search for the "best" response to the observed second order properties of ReV's. The Markovian model, based on a theoretical understanding of underlying mechanism, gives more information about the occurrence of regionalized variables and respond to all properties. Random model and the so-called hole effect structure can be easily defined as a special form of the Markovian model (Azun, 1983). An estimation of any second order properties of regionalized variables may be computed through (N-1) lag. However, the dependency between the regionalized variables may be deemed to have "died out" after the so-called stationarity width (range). In practice, the estimation is carried out through 25% of the total number samples available. Therefore, the large fluctuations around the zero level and variance for correlogram or covariogram function and semivariogram function, respectively, cannot be observed. Since the number of pairs involved in the estimation of higher second order properties is small, the estimation variance at those lags is large. There is no need to show higher order estimated second order properties. After using one of any kriging procedure for block estimation, the distribution function of average grades has the same mean as the drilling sample grades but

Jan 1, 1986

By A. K. Mukherjee, J. E. Dorn, J. D. Mole

Investigations were carried out on the effect of polyslip on the strain hardening of aluminum single crystals. The orientations investigated were those lor which the tensile axis was in the [001], [111], [112], and [012] directions plus another for which the Schmid angles for {111}(110) slip were 1 deg. The experimental data were analyzed on a model based on the intersection of dislocations with particular emphasis on the effect of polyslip on the activation volume for inter-section. It is shown that the rate of strain hardening inreases for those orientations wherein attractive dislocation intersections occur and that those orientations which produce the greater number of such intersections exhibit the greater strain hardening. Good correlation of the data is obtained with the concept that attractive junctions, as proposed by Saada, Play an important role in accounting for the rate of strain hardening. EXISTING concepts on the nature and cause of strain hardening in fcc metals have been deduced principally from experiments on the deformation of single crystals under single slip. The effect of crystal orientation on the shapes of the stress-strain curves for single slip have been summarized by seegerl and more recently by Clarebrough and Hargreaves.2 Tensile specimens whose axes fall near the center of the [001]-[011] line of the standard triangle of the stereographic projection exhibit the longest range of easy glide (Stage I) and the lowest rates of linear hardening (Stage 11) whereas specimens whose axes lie near fie [001]-[111] line of the standard triangle have limited or no easy-glide range and exhibit somewhat higher linear strain-hardening rates. Specimens whose axes lie near the [001] or the [ill] poles do not exhibit easy glide and have the highest rates of linear hardening. Kocks3 has shown that the highest rates of linear hardening Occur under Polyslip when the tensile axis coincides with the [111] or the [ 001] pole. Since the rate of strain hardening is sensitive to specimen orientation and the incidence of polyslip, these relationships might help to discriminate between various dislocation models for strain hardening in fcc metals. Previous attempts to analyze the effect of orientation on strain hardening,1"3 however, did not provide a unique answer to this problem. Consequently the present investigation was undertaken wherein additional data, particularly that for the effect of polyslip on the activation volume for intersection, was also determined in order to provide more complete information on the details of strain hardening. Whereas analyses of these data reveal that several recommended models for strain hardening are at variance with the facts, good correlation of the data is obtained with the concept that attractive junctions4 play an important role in accounting for the rate of strain hardening. I) EXPERIMENTAL APPROACH seegerl demonstrated that slip in fcc crystals at low temperatures is dependent on thermally activated intersection of glide dislocations with forest dislocations. This has been confirmed by tests on single crystals of aluminum by Mitra, Osborne and Dorn5 and on polycrystalline aluminum by Mitra and Darn.' Thus in accord with Seeger's theory, the shear strain rate, ?, below a critical temperature, T, is where .V is the number of points of contact per unit volume between forest dislocations and glide dislocations, A is the area swept out per successful intersection, b is the Burgers vector, v is the frequency of vibration of the segment of the glide dislocation undertaking intersection, U is the activation energy for intersection, k is Boltzmann's constant, and T is the absolute temperature. For aluminum, which has an extremely high staeking-fault energy, the constriction energy is negligibly small and therefore the activation energy decreases practically linearly with the stress according to as will be recomfirmed later, where Uo is jog energy at the absolute zero, G and Go are the shear moduli at the test temperature T and O°K, respectively, L is the spacing of the forest dislocations, t is the applied shear stress for slip, and tGo is the stress field that must be surmounted athermally.

Jan 1, 1965