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By J. H. Nelson

An outline survey of the economic outlook for the United States export trade in petroleum products resolves itself broadly into two general divisions; first, a consideration of our present position in this trade, and second, a discussion of the visible factors which promise to affect appreciable changes in the immediate future in that trade. The United States PetRoleum Exports of majoR Petroleum Products 1925, 1926 and 1927

Jan 1, 1928

By H. F. Yancey

COAL mine operators recognize coal as an abrasive material, because the wear of drilling, cutting, and conveying equipment is reflected as a cost item for replacement of parts. Similarly, industrial consumers of coal experience abrasive wear on all coal-handling equipment. Operators of pulverized fuel plants are doubtless most keenly aware of the abrasiveness of coal, because under the high contact pressures developed between coal and metal in pulverizers, abrasive wear is increased many fold. Moreover, experience in operating pulverized fuel plants has demonstrated that some coals are much more abrasive than others.

Jan 3, 1951

By B. H. Sage

ATTEMPTS have been made to predict the volumetric and phase behavior of naturally occurring hydrocarbon mix-tures1-5 but these methods have not been extended to the higher pressures and tem-peratures that are currently encountered in some producing formations. Furthermore, the methods of prediction at present avail-able have not been tested in a sufficient number of cases to ensure their applica-bility to all naturally occurring hydrocar-bon mixtures, even at the lower pressures and temperatures. For these reasons the behavior of a number of hydrocarbon mix-tures from a field in which the subsurface pressures are above 4500 lb. per sq. in.? and the temperatures are in the neighbor-hood of 250°F. was investigated.

Jan 1, 1940

By Julien Deby

THE sinking of a deep shaft is always a serious undertaking, especially when the strata to be traversed are of great hardness, or when they are feebly coherent or highly saturated with water. In the, first case, that of solid rock, modern appliances, such as the rock-drill, put into motion by air-compressors, along with suitable explosives, will generally answer the purposes of the mining engineer until he has reached the main water-levels. When these have

Jan 1, 1877

By Brahm Prakash, R. Schuhmann

Chemical conditions for flotation and nonflotation of quartz with oleic acid as collector and barium, calcium, aluminum, iron, and tin as activators were studied using a simple vacuum-flotation technique in glass-stoppered graduates. The detailed study of barium activation led to an interpretation based on ideal Langmuirian chemisorption.

Jan 5, 1950

By Julien Deby

The sinking of a deep shaft is always a serious undertaking, especially when the strata to be traversed are of great hardness, or when they are feebly coherent or highly saturated with water. In the. first case, that of solid rock, modern appliances, such as the rock-drill, put into motion by air-compressors, along with suitable explosives, will generally answer the purposes of the mining engineer until he has reached the main water-levels. When these have

By Subhas G. Malghan

The response of feldspar flotation to tallow diamine dioleate collector in the presence of sulfuric acid is studied using batch flotation experiments. Application of this nonhydrofluoric acid (non-HF) reagent system in the flotation of mineralogically and chemically different feldspar ores is compared with that of the conventional hydrofluoric acid system. The dependence of flotation recovery and concentrate grade on feed particle size distribution, conditioning time, pulp density, and pH, combined variation of collector and acid addition rates, sodium hydroxide concentration in the collector solution, and initial pulp pH Prior to conditioning is studied. The results have been discussed in relation to applicability of the non-HF system to plant trials, and the nature of the collector adsorption in the selective flotation of feldspar.

Jan 1, 1982

By E. C. Weichel, J. H. Carpenter, J. C. Detweiler, J. L. Gillson, J. P. Wood

ILMENITE, rutile, zircon, and other heavy minerals are found in small amounts in the sand that covers most of Florida. Small enriched deposits occur on the beaches and coastal dunes. One beach deposit east of Jacksonville was worked during World War I and another near Vero Beach during World War 11. Both ceased operation when the resumption of imports reduced prices.

Jan 8, 1953

By Kenneth Robertson

THEREi9 probably less known of this subject than of any other connected with the metallurgy of iron. In all the books that treat of this mattes, there are given analyses of slags, their chemical formulae, the loss of iron, etc. ; but few, if any, give the character of the iron made at the time ; none give analyses and physical characteristics of the ores and limestones used, and they present merely isolated examples from various furnaces, and consequently one is more frequently puzzled than enlightened after reading them. During two years I have had occasion to analyze the slags and many of the pig-irons from two furnaces, and for this article I have made analyses of all the different grades of pig made by them. A

By Alfred Weiss

The business world of tomorrow will experience a major change in its data communication systems, with the mineral industry being among those to feel the greatest impact of this change. This development can be expected to occur over the next two decades at a steadily increasing tempo. One major factor prompting this transformation is the fact that technological knowledge is doubling approximately every five years. Moreover, industry is becoming more and more dependent upon the flow and processing of information in its long-range planning, while government requirements and regulations demand increasingly detailed and precise information on plant operations.

Jan 1, 1971

By A. M. Gaudin, J. G. Morrow

FLOTATION requires the existence of a definite contact angle. This contact angle, the surface tension of the solution, and adsorption at the solid- fluid interface are quantitatively related. Adsorption of dodecylammonium acetate on hematite was measured for a wide range of concentrations of reagent in solution. Similar measurements for quartz have already been made.1 Contact angle measurements were then made on polished surfaces of hematite and of quartz immersed in aqueous dodecylammonium acetate solutions, and a functional relationship was sought between adsorption density at the mineral-solution interface and the contact angle. Finally, the surface tension of the aqueous amine acetate solutions was measured. These data were combined to give an evaluation of the work of adhesion for the three-phase system.

Jan 12, 1954

By Alden B. Greninger

THE study of mosaic structure of crystals1 has been confined until recently to the field of theoretical physics Crystallographers, in general, have neglected the subject, although X-ray crystallographers constantly make use of formulas for intensities of X-ray reflection as modified by mosaic structure Work on mosaic structure has centered chiefly on the task of proving or disproving the secondary-structure theory of Zwicky,2 and very little attention has been paid to the visible imperfections of crystals A Goetz has been responsible for most of the supposed experimental confirmations of Zwicky's theory 3 On the other hand, Smekal,4 and Orowan,5 among others, maintain that these is neither theoretical nor experimental evidence to substantiate Zwicky's secondary structure

Jan 1, 1935

By Carleton Ellis

The problem of the influence of hot surfaces upon gaseous combustion is one which, from a purely scientific standpoint, has engaged, for many years past, the attention of Prof. William A. Bone, of Leeds University and the Imperial College, London ; and as his recent work has been the direct outcome of earlier scientific investigation, it will be appropriate, by may of introduction, to review briefly the present position of science with respect to this important subject, as stated by Professor Bone. One may perhaps best arrive at an understanding of the term " flameless " or " surface " combustion by considering certain facts which differentiate it from the more familiar processes of

Jan 1, 1913

By S. N. Singh, M. C. Flemings

Results are presented of a detailed study on the combined influences of ingot dendrite am spacing and thermomechanical treatments on the structure and solution kinetics of high --purity cast and worked 7075 alloy. Solution kinetics were found to depend sensitively on ingot dendrite am spacing and on details of therrnomechanical processing, including amount of reduction and extent of&apos; solution treatment before reduction. An approximate analysis is given for rate of solution of nonequilibrium second phase in the cast and worked structres; results of the analysis are compared with experiment. MICROSEGREGATION in high strength aluminum alloys manifests itself as "coring" (composition differences within the primary aluminum-rich phase), and as interdendritic second phase. The mechanism of formation of the microsegregation is understood, and approximate prediction of the amount of second phase is possible for simple binary systems.1,2 When alloy elements or impurities are present in amounts less than their solid solubility at solution temperature, any phases forming from these elements are termed "nonequilibrium" and can be dissolved by appropriate solution treatment. The rate at which the nonequilibrium phases are removed depends sensitively on their spacing (dendrite arm spacing in the cast material, or band spacing in wrought material). When alloy elements or impurities are present in amounts in excess of their solubility at the solution temperature, second phase particles form an "equilibrium" second phase that does not dissolve in heat treatment and may, in fact, coarsen in such treatment. Usual commercial, high strength, wrought aluminum alloys contain nonequilibrium second phases that were not fully dissolved during ingot processing. They also contain equilibrium second phases resulting from impurities present in amounts greater than their solubility. As has been shown by Antes, Lipson, and Rosenthal,3 and will be demonstrated further in a subsequent paper by the authors,4 significant improvements in mechanical properties of high strength alloys can be achieved by reduction or elimination of these second phases. Methods of elimination are 1) to employ high purity materials to minimize amounts of equilibrium second phase, and 2) to employ suitable thermomechanical processing techniques to fully eliminate nonequilibrium second phases. Work reported herein comprises a study of selected thermomechani- cal processing treatments, and of their influence on solution kinetics of wrought high purity 7075 alloy. EXPERIMENTAL PROCEDURE Melting and Casting. The bulk of the work reported was performed on a single ingot of high purity 7075 alloy. The ingot was 4 in. by 4 in. by 8 in. high, uni-directionally solidified following a procedure previously described.5 The mold was heated to 1350°F before pouring the melt. The bottom chill was carbon coated stainless steel. Water was circulated through the chill after the melt was poured. The 7075 alloy was prepared from high purity virgin material (aluminum, zinc, magnesium) and from master alloys (Al-50 pct Cu, A1-15 pct Cr, A1-5 pct Ti). Final measured melt composition (wt pct) was: Zn Mg Cu Cr Ti Fe Si Al 5.70 2.28 1.35 0.18 0.15 <0.002 <0.012 bal Melting was done in a silicon carbide crucible; all tools were coated with zircon wash to minimize iron contamination; degassing was by bubbling chlorine through the melt. che-rmomechanical Treatments. Detailed studies were made on material taken from a location approximately 13 in. from the chill and 51/2 in. from the chill (i.e., from 1 in. thick slices taken between 1 and 2 in. from the chill and between 5 and 6 in. from the chill). Solution treatment was done at 860°F in an air-circulating furnace with a "bottom drop" arrangement to achieve minimum delay time between solution treatment and quench. Samples solution treated in this way were 2 in. by 2 in. by 1 in. Temperature of the quench water was approximately 10°C. Mechanical reduction was by cold rolling. Samples 11/2 and 51/2 in. from the chill were treated for 12 and 24 hr, respectively, before cold rolling. Reduction by cold rolling was then 4/1, 16/1, and 35/1. In each case, several intermediate anneals (1/2 hr at 860°F) were used to permit reaching the final thickness without cracking; two such anneals were used for the 4/1 reduction, five for 16/1, and six for 35/1. After working, materials were again solution treated for various lengths of time from 0 to 48 hr and quenched in water. Structural Measurements. Secondary dendrite arm spacings were measured using procedures previously described.&apos; For each measurement reported, five photomicrographs were first made at X75. Measurements were made of dendrite arm spacings in at least 20 different grains (grain structure was equiaxed). Grain size measurements were made by running a number of random traverses across photomicrographs of the samples and obtaining the mean lineal intercept. Measurement of the volume percent of second phase and porosity was done by quantitative metallography. A two-dimensional systematic point count was used

Jan 1, 1970

By R. D. Carter

Methods are presented for calculating the performance of multiwell gas reservoirs. These methods account for two-dimensional, unsteady-state flow of a non-ideal gas through a heterogeneous formation. The performance can be obtained for gas reservoirs with known physical properties and configuration subjected to specified development and production schedules. These methods may prove helpful in optimizing the exploitation of gas reservoirs. The numerical solrrtion procedures given for this non-linear problem are extensions of known techniques for the linear diffusion equation. Two of these procedures are based on a new difference equation given by Saul&apos;ev. Limitations and advantages of these procedures are discussed. An example solution is presented and is used to compare the calculation methods. INTRODUCTION Li planning the operation of a multiwell gas reservoir, it is desirable to predict its performance for each alternate development and producing schedule under consideration. This paper presents three numerical procedures that can be used to calculate such gas reservoir performance using a digital computer. These methods account for two-dimensional transient flow of a non-ideal gas within the reservoir. Extension of these methods to three-dimensional flow is possible. The paper is divided into three parts. The first describes the problem for which a solution is wanted and three numerical procedures that can be used to obtain solutions. The second discusses the information necessary to set up a problem. This part will be of greatest interest to the field engineer. The third gives data and results for an example problem. PROBLEM AND SOLUTION METHODS In the following development, a gas reservoir is regarded as a sealed, porous, permeable, heterogeneous body in which a single, non-ideal gas phase is flowing. Flow is permitted in the x- and y-horizontal directions, but is considered to be negligible in the vertical or z-direction. The reservoir can be tapped by one or more wells. Methods to be described provide a basis for calculating the complete performance of the reservoir, including rates and cumulative production from the wells, and pressure distribution and decline in the reservoir. If the isothermal flow of a non-ideal gas obeying Darcy&apos;s Law occurs in two dimensions in a region R, the governing equation in this region is:

Jan 1, 1967

By S. Le Fevre

The application of electricity to the mining and beneficiation of the magnetic iron ores of the Mineville, N. Y., district, on Lake Champlain, has resulted,in economies and enhanced quality of product, without which only a comparatively small quantity of the present output could be marketed. The output of the Witherbee, Sherman & Co. mines is about 700,000 tons per annum, and of this about four-fifths is treated by magnetic separation to increase the iron content and reduce the phosphorus. The use of electricity for the magnetic separation of the ore from the gangue is therefore of primary importance, and makes possible the application of electric power for mining and preparing the ore for concentration. The fact which speaks loudest in favor of the application of electricity is this: It is possible for about 25c. per ton of shipping ore to furnish all the power required to put the ore on cars. This includes mining a hard ore underground, from a depth of 900 ft., hoisting to surface, crushing to $ or 8 in. in size, and separating from the gangue. This also includes lights about the works, and all miscellaneous power, such as about the shops. The first plant for the generation of electric power for use at Mineville was completed in 1903, and was one of the first for the application of electricity to mining iron ore. This was a Nordberg compound condensing steam engine, direct connected to a 750-kw. alternating-current generator, 3,300 volts, 3 phase, 25 cycles. All the plants added later use the same current but with higher voltage. The map, Fig. 1, shows the power plants and the transmission system; Figs. 2 and 3 are views of the shaft houses and the mills. The power from the first plant was distributed to Mills 1 and 2, one 2,500 cu. ft. compressor, and to the Harmony hoist, which was driven by a 300-h.p. motor operating four 10-ft. drums. Our experience with the hoist covers largely the development of electric hoisting from 1903 to date, and in some cases improvements were worked out to satisfy our needs. The motor is still operating as installed, but the control apparatus has been radically changed several times. When installed, the iron re-

Jan 1, 1915

By P. K. Koh

Isothermal salt bath annealing of 0.014-in. thick 3 pct Si-Fe sheet was conducted at temperatures ranging from 927" to 1260°C in order to investigate the grain-growth behavior. Within the temperature range studied normal grain growth did not take place; instead nucleated grain growth prevailed. The nucleation frequency was found to increase with the annealing temperature, with corresponding decrease in grain diameter of ultimate secondaries after long-time annealing. Large secondaries grown by low-temperature isothermal annealing are essentially of (110)[001] orientation, and the (110)[001] texture is strong. The relatively small secondaries grown by high-temperature isothermal annealing also have orientations near (110)[001] as an average but widely scattered; thus the amount of (110)[001] texture is found to decxease with isothermal annealing temperature. Grain growth and texture development at various annealing temperatures can be described by families of sigmoidal curves with the time axis. ThE cube-on-edge (110)[001] texture and predominating large secondaries in fully annealed 3 pct Si-Fe are customarily produced by a 1100°C annealing of a primary recrystallized sheet. On annealing the primary recrystallized sheet above the temperature at which secondary recrystalliza-tion starts May and turnbull&apos; have demonstrated that secondary grains decrease in size as the temperature is increased. The phenomenon was attributed to a decrease in the (G/N) ratio where G is the growth rate of secondary grains and N is their nucleation frequency. In addition, the growth of grains in orientations rather far from (110) [0011 occurred. The present investigation is devoted to detailed rate studies of the same phenomenon. Mi-crostructure, magnetic anisotropy, and texture data were obtained on strips of 3 pct Si-Fe isothermally annealed for various lengths of time in a BaC12 salt bath at temperatures ranging from 927&apos; to 1260°C. The texture results are reported elsewhere.2 EXPERIMENTAL PROCEDURE Commercial 0.014-in. cold-rolled silicon-iron strip (3.16 pct Si), prepared by two stages of cold rolling with an intermediate short anneal, was given a decarburizing 3-min anneal at 800°C. Metallo- graphic studies indicated complete recrystallization. In order to provide a protective atmosphere and to obtain a rapid rise to an elevated temperature, a BaC12 and NaCl fused salt bath was used to heat samples isothermally at temperatures from 927" to 1260°C for various lengths of time. Torque magnetometer measurements were made on 1-in.-diam disc specimens before and after annealing, since magnetic torque curves supply information on textures and texture changes. Surface layers of the strip samples were polished and etched to reveal the grain structure. The diameters of grains were measured from micrographs at X100. The average value of diameters of matrix grains was established. Individual grains in the micrograph were cut out separately along grain boundaries. These grains were classified either as matrix grains or growth grains. The percent weight of growth grains in the cut-out patterns was reported as percent growth. Manv of the individual grains in the annealed samples were large enough to be X-rayed with a 5-mil beam for Lauegrams. Complete (110) pole figures were obtained for the primary recrystallized structure and short-time annealed structure with CoKa radiation at 30 kv in the back-reflection range, such as (220) for (110) poles, as described recently by Newkirk and ~ruce.~ Both the X-ray optics and the technique for pole figure differed slightly from those adapted previously.4

Jan 1, 1960

By Donald M. Hausen

Microscopic evaluation of trace quantities of metalliferous phases in flotation products requires counting large numbers of particles. Particle counts of many thousands may be required for precision, but cannot be obtained practically by conventional microscopic techniques. A less tedious microscopic method for evaluating trace sulfides in mill tailings was developed for the O&apos;okiep Mining Co. in South Africa. Hundreds of thousands of particles were evaluated by this method called "gross-counting." Gross-counting consists of counting microscopic fields rather than point-counting individual particles. Total counts are calculated by multiplying the average number of particles per field by the total number of fields examined over the entire mount. Total gross-counts range from about 20,000 particles for +200 to 100,000 or more for -400 mesh size material in lucite mounts. Sulfides and metallic particles in each field are identified and tallied along with field counts. Totals for each type of metallic particle are divided by the total gross-count to give volume percent which is corrected to weight percent by specific gravity factors.

Jan 1, 1973

By Paul A. Bailly

“For innovative leadership in bringing about a quantitative rationality to mineral exploration; for the impact his efforts and wide respect have made on national mineral policy issues; for his effective managerial role in major mineral discoveries; and for his lecture, ‘Managing for Ore Discoveries.’”

Jan 1, 1980

By J. W. Snavely

WITH all the advantages of handling bulk materials by means of belt conveyor also go some problems, one of the most persistent being that of cleaning. When sticky materials are being carried; the build-up of material on the return idler rolls results in difficulty of belt training. Much attention has been given to the problem of cleaning conveyor belts, and a great variety of cleaning devices have been developed. Even the best involve troublesome maintenance, and none can completely remove the fine particles imbedded in the belt cover, which cause rapid wear of the return idler rolls, and at the same time, of the belt cover as well.

Jan 12, 1951