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Jan 1, 1941

Jan 1, 1910

Jan 1, 1949

Jan 1, 1939

Jan 1, 1929

Jan 1, 1929

Jan 1, 1898

By M. L. Sisson, G. H. Rupp, R. L. Hair

THE iron ore supply for the Pueblo plant of CF&I is obtained from the Sunrise mine in Wyoming and the Duncan and Blowout mines near Cedar City, Iron County, Utah. The Sunrise mine is an underground operation while those in Utah are open pit.

Jan 11, 1953

By Jules E. Jenkins

In the past quarter century the seismograph has I played an increasingly important role in evaluating vibratory effects transmitted to adjacent communities by industrial blasting operations. In this period research has advanced through two major phases-from falling pin seismometers to three- component recording seismographs. The initial phase of this research is now regarded as the era of recording, during which the seismograph merely recorded occasional events. It has emerged from this stage into the era of control and analysis and in this later period has been recognized as a full-fledged industrial tool. Although the falling pin machines of earlier years indicated probable amplitudes of industrial blasting vibrations, they gave no reliable measure of such displacements, nor did they provide essential information concerning direction or frequency of motion.

May 1, 1956

By T. Okubo

Gold is generally recovered from silver anode slime by electrolysis in the final step of the copper anode slime treatment. In the present investigation, rapid and direct hydrometallurgical separation and recovery of gold in the early step of the process is studied. Gold is recovered just after the elimination of copper and selenium from copper anode slime. The studied process consists of: (a) oxidizing roasting for selenium elimination, (b) sulfuric acid leaching of the calcine for copper removal, reduction of gold in the liquor by the use of proper reductant such as hydrogen peroxide (production of gold powder), (el nitric acid treatment of gold powder for further purification and (f) melting and casting of gold. Laboratory and miniplant testwork showed that the extraction ratio of gold by chlorine leaching was 99 % up and four nine gold ingot could be recovered without electrolyses.

Jan 1, 1984

By E. C. Wright

FOR many years the cost of making pig iron and steel in the Birmingham district has been about the lowest in the United States. The close proximity of the important raw materials such as coal, iron ore, limestone, and the large available scrap supply made it possible to assemble all of the important ingredients necessary for steel-making with only nominal costs for transportation. Both iron ore and coal were being mined in this district at one time for about $1 per ton from underground operations. At that time mining wages were low everywhere and the labor rate in the South was considerably below that of other mining districts. This situation persisted until the emergence of labor unions as an economic and political force, emigation of southern labor to northern plants, and continued growth of industry in the South in the years following the depression of 1932. Since that time union organizing of miners and steel workers throughout the nation has increased labor costs in mining and steelmaking. This influence has been felt particularly in underground mining operations since the proportion of labor cost to total cost is still high. The previous advantage in basic labor rate in the South has been almost entirely eliminated by the equalization of labor rates in basic industries by national unions.

Jan 12, 1950

Jan 1, 1945

Jan 1, 1912

Jan 1, 1968

By N. D. Policow, J. S. Orphanos

Dewatering fine clean coal fractions, -595µm (-28 mesh), represents one of the most difficult and costly separations in typical plant circuits. Since 1969, the screen bowl centrifuge has offered an economical alternative to filtration/thermal dyer combinations. The performance of screen bowl centrifuges has been continuously modified and improved to dewater not only coarser coals, but also today's variety of ultrafine material. Test comparisons with alternative methods show the screen bowl centrifuge to be most cost effective and efficient when all factors are considered.

Jan 1, 1984

By H. A. Koch, R. L. Slobod

This paper discusses a new oil recovery process called the "miscible slug process." This process involves the injection of propane or LPG into the reservoir prior to gas injection. The operating conditions are maintained so that the slug is miscible with both the reservoir oil and the injected gas phase. Thus, a miscible phase displacement is achieved, and high recoveries are obtained from the area of the reservoir contacted. The most striking discovery of the laboratory study which included displacements from cores up to 123 ft in length was that relatively small slugs of LPG are effective over reservoir distances in the miscible displacement of oil. This makes possible the commercial application of the process. The important factors controlling the size of the slug are: (I) reservoir length, (2) reservoir fluid composition, and (3) reservoir pressure at the displacement front. Of lesser importance are the effects of injection rate and porous medium type. Questions which have not been completely answered deal with the effects of gravity and reservoir inhomogeneities on the process. INTRODUCTION One of the major problems facing the oil industry today is recovery of the large fraction of the discovered oil which will remain unrecovered unless some new processes are found. Water flooding has been one successful method used to increase recovery over natural depletion. But even successful water floods may leave 25 to 40 per cent of the pore space filled with residual oil. Recently a process which involves the use of thermal energy has been reported1,'*' which may prove useful in increasing recovery from shallow reservoirs containing highly viscous crudes. This paper deals with a new oil recovery process involving use of miscible phases to displace the oil from the reservoir. Miscible phase displacement oil has been an intriguing idea because the elimination of capillary effects in the reservoir leads to 100 per cent recovery in the areas contacted by the miscible displacing phase. The big deterrent in the past to the practice of miscible phase displacement has been the high cost involved in using large volumes of solvent in the process. The use of high pressure gas to achieve a miscible phase displacement of reservoir oil has been reported4,5 as one economically feasible method. However, this process calls for the maintenance of pressures above 3,000 psi at the dis-placement front. The process described in this paper is not restricted to high reservoir pressures; the only qualification being that the slug of material which is injected into the reservoir must be miscible with both the displaced oil 2nd the displacing phase. Two such cases are the use of an alcohol slug followed by water to achieve a mis-cable water flood, and the use of a low boiling hydrocarbon slug such as propane followed by gas to achieve a miscible gas drive. This paper will deal specifically with the propane dug process. This process will obtain a miscible phase displacement at pressures as low as about 1,200 psi at a reservoir temperature 01 150°F. The process is very simple. The propane displaces oil completely at one front because it is miscible with the oil, and gas displaces the propane completely at a second or trailing front because it is miscible with the propane. A small band of propane should thus remain wedged between the gas and oil phases. This idea has been called the "miscible slug process."6 Unfortunately, the propane slug will become diluted as it flows through the reservoir. This results from a mixing action since the fluids flow through a complex reservoir porous medium rather than simple capillaries. Fig. 1 diagrams a miscible slug displacement. The effects of some of

Jan 1, 1958

The following list contains the names of members of whose deaths notices have been printed in MINING AND METALLURGY during the year ending April 1, 1939. Biographical sketches published in MINING AND METALLURGY are indicated in the last two columns.

Jan 1, 1942

By R. W. Raymond

The death of Louis Janin, which took place Mar. 6, 1914, at Santa Barbara, terminated the earthly career of almost the last survivor, and one of the most illustrious members, of that group of American mining engineers and metallurgists who, in the last quarter of the nineteenth century, directed the development of the mineral resources of the Pacific slope. Louis Janin was born in 1836 at New Orleans. His grandfather, an officer in the French army, had emigrated to this country, with his family, at or before the outbreak of the French revolution. His father became an

Jan 1, 1915

By S. D. Dahlgren

ORDERED G.P. zones having the cesium chloride structure were found to exist in the bcc iron-rich grains of an Fe-Au-Cu alloy that had been supersaturated with approximately equal atomic percentages of gold and copper, and aged at 400° and 350°C. Streaks and superlattice spots in electron diffraction patterns revealed the presence of the ordered zones in the aged material. The ordered Ll2 structure is commonly found for precipitates in fcc metals (e.g., Ni3A1 in nickelL7') but it is uncommon to find precipitates in bcc metals having the cesium chloride structure. The formation of the G.P. zones caused age hardening of the grains. Samples containing 3.8 at. pct each of gold and copper (with the remainder being iron) were annealed at 95@ or 1125°C in quartz capsules and were quenched by breaking the capsules under water. X-ray diffraction patterns revealed two solid solutions in the quenched samples. One solid solution was bcc and the other was fcc. The microstructure consisted of iron-rich grains of 0.3 mm diam surrounded by a yellow gold-copper-rich grain boundary network. The Au-Cu phase diagram %hows continuous solid solubility of gold and copper with ordered phases forming below 410°C. None of the ordered Au-Cu phases have the cesium chloride structure. Both Fe-Au and Fe-Cu phase diagrams3 show extended miscibility gaps and only terminal solid-solution phases. Consequently, it is reasonably certain the iron-rich grains consisted of an a-phase terminal solid solution, and the grain boundary network consisted of a gold-copper-rich terminal solid solution. Lattice parameters of the quenched solid solutions were consistent with the suggestion that the quenched phases were terminal solutions. The lattice parameter of the bcc phase (2.879A) obtained upon quenching from 950°C was higher than that (2.866A) for pure iron. The fcc phase in this sample had a lower lattice parameter than that for a 50 at. pct Au and 50 at. pci Cu solid solution, i.e., 3.866 compared to 3.877A. The lattice parameter for the 50 pct Au and 50 pct Cu solid solution was interpolated from data for Cu-Au solid solutions.4 More gold and copper were soluble in iron at 1125°C than at 950°C as indicated by a 0.012A increase in the bcc lattice parameter for a sample quenched from 1125°C. After the alloy had been quenched from 950° and 1125°C, the bcc lattice parameters were 2.879 and 2.891A1 respectively G.P. zones having the cesium chloride structure-which formed during low-temperature aging—were detected by electron diffraction and observed with electron transmission microscopy. In Fig. 1, the asymmetrical streaks parallel to ( 100) directions indicate that platelike G.P. zones had formed parallel to (100) planes of the matrix. The direction of streak asymmetry shows that the bcc unit cell of the G.P. zones was larger than the bcc cell of the matrix. The ordered cesium chloride structure is indicated by low-intensity superlattice spots at 010 positions which are nonallowed for bcc structures. The superlattice spots are streaked; therefore they are from the G.P. zones and are not caused by rel-rod effects of a thin matrix phase. The appearance and size of the zones observed in electron transmission microscopy and the appearance of the asymmetrical streaks in the electron diffraction patterns for the Fe-Au-Cu alloy were the same as those observed for a similarly treated Fe-Au alloy.' Ordered G.P. zones were detected also for an Fe-Au-Cu sample aged only at 400°C. The production of the ordered cesium chloride structure zones by low-temperature aging of super-

Jan 1, 1968

By Y. H. Liu, G. W. Powell

Thin foils made from the gold-rich region of- short (0.15 mm)Au-Ag diffusion couples annealed at 880°C for 1 hr were examined in ax electron microscope and the structures were compared with that of pure gold subjected to identical heat treatments. The couples underwent Plastic deformation (bending) during the diffusional anneal. The foils prepared from the diffusion zone have a higher dislocation density and incidence of subboundaries than pure gold. The plastic bending of the couple can be interpreted in terms of the climb of edge dislocations, which are pavallel to the bend axis, along the direction of diffusion. THE interaction of lattice defects during interdiffu-sion between two metals has been considered by several investigators. In particular, da Silva and Mehl,1 Barnes,' and Bardeen and Herring3 have proposed models based on interactions between point and line defects to account for the Kirkendall effect (marker movement). Each of these models is based on dislocation climb, which can either add or remove lattice planes, induced by an under- or supersaturation of vacancies. A theoretical treatment of the nucleation and growth of voids by the condensation of vacancies has been presented by Seitz.4 Stresses can arise in a binary diffusion couple as a result of the vacancy flux and the gradient in the lattice parameter. rinkmman' has investigated the effects of diffusion-induced stresses on void formation; the results of his analysis suggest that voids can form and grow under the influence of these stresses in the absence of an excess vacancy concentration. The relationships between vacancy supersaturation and diffusion-induced stresses and void formation have been elucidated also by Balluffi and seigle6 who concluded that the stress generated by a vacancy supersaturation aids the growth of voids. Experimental evidence which indirectly shows that stresses are produced by chemical diffusion has been obtained by several researchers.2,7-9 This evidence consists in part of the observation by light microscopy of the formation of subgrains, a process characteristic of the high-temperature deformation of some metals during creep.'0 More striking, however, is the plastic bending of short (0.2 mm) Cu-Ni couples observed by Barnes2 and of boron-doped silicon crystals reported by Queisser.9 Diffusion-induced dislocations in iron and silicon have been investigated by Ainslie et a1.11and Schwutte and Queisser,12 respectively, the former using transmission electron microscopy and the latter an X-ray transmission technique. Matthews and Crawford13 observed the formation of boundaries by the climb of interfacial misfit dislocations in thin, vapor-deposited Au-Pd couples diffused in situ in an electron microscope. In order to obtain additional information on the phenomena associated with defect interaction and diffusion-induced stresses in binary couples, an electron transmission study of foils prepared from the diffusion zone of short Au-Ag couples was undertaken. The initial objective was to investigate the processes occurring at various points of the diffusion zone. Subsequent research demonstrated that foils could be prepared only from the gold-rich region of the diffusion zone using the technique described herein. EXPERIMENTAL PROCEDURE Preparation and Annealing of the Diffusion Couples. The couples were made from annealed, high-purity (99.999 pct). polycrvstalline gold and silver sheets (0.075 mm thick). Shall (0.075 by 5 by 17 mm) elec-tropolished coupons of gold and silver were pressure-bonded by heating the two metals in a graphite device to 770°C and holding at this temperature for approximately 30 min. The quality of the bond was ascertained by metallographic examination at 150 times. Each couple subsequently was annealed at 880°C for 1hr; under these conditions, the extreme portions of the

Jan 1, 1968