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By T. Egleston

The manufacture of charcoal in kilns was declared many years ago, after a series of experiments made in poorly constructed furnaces, to be unprofitable, and the subject is dismissed by most writers with the remark that in order to use the method economically the products of distillation, both liquid and gaseous, must be collected. It is asserted with truth that the number of kilns required for a large production of iron would be so great that it is doubtful whether any works would be justified in making the necessary outlay for their constructiou, but it can also be asserted with equal truth that for any such production in a given locality the use of charcoal as fuel would be eqnally unjustifiable. It appears to have been forgotten that there were other manufactures besides iron in which large amounts of charcoal were used, but these consumers seen] to have been guided entirely by the results of the experiments of the iron men, who necessarily made the largest qnantity of it. Some authors speak in a doubtful way of the quality of the charcoal produced, and a few concede that with great care good charcoal can he made in kilns, but that most of the workmen do not like kiln 'charcoal. This is the real secret of the opposition to this method of manufacture. Most of these objections were written when charcoal was the most important fuel used by the iron manufacturer, and when what was a largeproduction of iron for several furnaces was less than that produced by a single modern one, in localities where other fuels can be had. Almost all that has been written on the subject related to the use of the fuel for the manufacture of iron in the blast furnace, where very peculiar properties are required, and where the qnantity produced is limited by the height of the furnace, and this in turn by the crushing resistance of the charcoal. A large production was, therefore, only possible when the best and hardest woods were used. Of all these objections there is not a single one which is not eqnally applicable to any method of charcoal manufacture, whether it be meilers, pits, or furnaces. Until recently, therefore, the manufacturers of charcoal iron

Jan 1, 1880

By Edward O’Toole

THe Pocahontas district occupies the extreme southern end of West Virginia, principally McDowell, Mercer and Wyoming counties, and a part of Tazewell county, in southwestern Virginia. The first record of the coal field is a report by Prof. J. P. Lesley, of Pennsylvania, about 1880, in which he mentions a coal opening at the upper end of Abbs Valley, Tazewell county, Va. C. R. Boyd, a mining engineer of Wytheville, Va., published a series of articles in 1881, mentioning coal on Indian Creek, Tazewell county, and on Horse Pen creek, which coals, he stated, extended toward the Ohio River. He also mentions the Abbs Valley coal reported by Lesley. In 1881, F. J. Kimball (who became president of the Norfolk & Western R. R. in 1883)) after examining the Scott mine in Abbs Valley, went northward across Abbs Valley Mountain to the place now known as Pocahontas, where he located what has since been called No. 3 vein of Pocahontas coal. In November, 1882, Jed Hotchkiss and others prepared a cross-section of the Flat Top Mountain coal measures, some notes on which were published by Mr. Hotchkiss, between 1880 and 1892, under the title of " The Virginias.' In May, 1881, the Norfolk & Western R. R. was organized through the purchase of the Atlantic, Mississippi & Ohio R. R., an old line running from Norfolk, Va., to Bristol, Tenn., with branches from Petersburg to City Point and from Glade Springs to Saltville. At that time, charters had been granted for three railroads tributary to the New River Valley, but their proposed routes would indicate that the promoters were concerned with minerals, timber, and a connection with the Chesapeake & Ohio R. R., rather than the development of any coal in the Pocahontas district. One of them was projected to extend up Bluestone River a short distance, but not far enough to reach the coal in the Bluestone Valley, and a little grading was done for a narrow-gage road between New River Station and a point in Giles county, Virginia, near the West Virginia line. All charters and railroads in this district were acquired by the Norfolk & Western R.R.

Jan 1, 1925

By B. J. Shaw, R. Kossowsky, W. C. Johnston

High purity (99,95) Ni-51 wt pct cr eutectic alloy was unidirectionalty solidified at rates of 0.1 to 8 in. per hr. The resulting material was characterized by large grains, approximately 0.5 mm in cross section and extending through almost the entire length of the specimen, parallel to the growth axis. The eutectic structure of specimens the growth at -1/3 The per hr consisted of a continuous nickel-rich phase and chrome -rich lamellae approximately 2 thick, spaced about apart. Specimens were tested in compression at temperatures ranging from —196 to 850"C over which range the 0.2 pet yield strength dp -creased from 160,000 p si to 35,000psi, respectively. Swaging to 40 pet reduction in area, followed by a 30-min anneal at 1000c to remove residual cold work, increased the 0.2 pet yield to 260,000 psi at -196°C, dropping to 35,000 psi at 850°C. The increase in strength was attributed to a residual cell structure. The strength of the alloy could be rationalized by the simple rule of mixtures if one assumed that additional strength is derived front a size effect characterized by is petch equation IN recent years there has been increasing interest in dispersion and second phase strengthening in materials needed for high-temperature applications. inm role of structure on the mechanical The of such alloys has been well established of such some extent accounted for theoretically. and to of how the strengthening mechanisms due to fibers and lamellae operate has been reduced to its fibers form by the fabrication of composites of strong rods unidirectionally aligned in a From work on tungsten-fiber-reinforced copper, for example, it was established that the "Rule of Mixtures" could explain the strengthening.12 " some what more sophisticated technique for introducing strong fibers into copper matrix was used by Hertzberg strong Kraft3 who unidirectionally solidified the copper-chromium eutectic. The use of unidirectionally fied eutectics has advantages in that there are no matrix-fiber wetting problems and fine fibers are automatically aligned and uniformly fiber However, one Is restricted to a specific volume fraction of the second phase. Nevertheless, even though the volume fraction is fixed, the rod or lamella thickness, , can be varied by controlling the freezing interface velocity. Alternatively, the grown material may be worked down by swaging or rolling. Embury and Fisher, " using this approach, drew down pear lite in iron and studied the mechanical properties iron and that the yield strength, oy, was properties.proportional They that d was the wire diameter. It could be inferred that was also proportional to but the work hardening had to be taken into consideration at the same time. By varying the growth rate of the cadmium-zinc lamellar eutectic, Shaw'1 showed that was proportional to without the introduction of work hardening and suggested that the lamellar interface itself contributed to the strengthening of the composite. In this investigation we have evaluated the mechanical properties of the unidirectionally solidified fec-bec eutectic Ni-Cr. This eutectic was selected because it presented the possibility was selected beca temperature, and high corrosion resistant alloy, and also represented a hard-soft phase combination with two completely different slip systems. Specimens were tested in compression and tension up to 850°C and a detailed study of the micro structure as a function of plastic strain and temperature was carried out by light and electron microscopy. It was shown that the composite strength tested in compression can be accounted for by the simple rule of mixtures if one allows for an additional term representing the effect of Intereprese EXPERIMENTAL PROCEDURE 1) Unidirectional Solidification. Fig. 1 is a schematic drawing of the apparatus used to produce 0.2 in. diam by 12 in. long alloy ingots. The crucible tube is alumina, containing the charge which has been is swaged, or machined to 0.195 in. diam. The lower end of the tube is immersed to 0 .195in in.d iam. The upper end is supported by a 10 mil nichrome wire which lowers the crucible mil nic hr the] wire at a prescribed rate. Surrounding the furnace is a graphite susceptor into which a control thermocouple is inserted. The furnace is insulated with fiberfrax and enclosed in a quartz tube. There is a sliding seal at the bottom around the crucible and one on the top so that an atmosphere may be used for the sample and suscep tor. The power for the furnace is supplied from a 10-kw, 450 kc generator. The skin depth (the skin depth at which the field falls to l/e of its value at the outer surface) for graphite (p = 10 (j-ohm-cm) is 0.1 in. at this fre-

Jan 1, 1970

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

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

By F. T. Selleck, H. H. Reamer, B. H. Sage

An experimental investigation was made of the effect of temperature upon the three-phase pressure associated with the propane-water and propene-water systems when hydrates were present. In addition, the characteristics of the propane-propene-water system were established over a limited range of ternperatureo under conditions such that hydrate was formed. The hydrate phase for this system may he a solid solution and the distribution of propane and propene in it is similar to that found in the coexisting hvdrocarhon liquid phase. INTRODUCTION A knowledge of the characteristics of hydrates of the hydrocarborrs encountered in industrial practice is of importance in connection with the design of process equipment. Villardl.1,2 carried out early studies of hydrates, and de Forcrand1 con-sidered the more probable compositions of the hydrates of hydrocarbons. Hammerschnid1 presented information about the propane-water and the isobutane-water systems. Scheffer5 studied the hydrate of hydrogen sulfide in detail, and de For-crand reported on the hydrates of krypton, argon, and xenon.1 Roberts and co-workers1,2 determined the nature of the hydrates formed in the methane-water and ethane-water systems. Carson and Katz10 studied the methane-propane-water, methane-pentane-water, and the methane-hexane-water systems in the four-phase region. The results of this rather extensive investigation indicated that the paraffinic hydrates formed solid solutions. The experimental evidence now available does not Support the existence of hydrates of the pentanes-antl-heavier hydrocarhons but it cannot be stated with certainty that such hydrates are not formed. Stackelherg. 11,12,13 made extensive studies of the crystal structure of paraffinic hydrate; by means of x-ray techniques and found that hydrates poses; a definite structure and composition. The existence of such a Structure does not preclude the firmation of Solid solutions of hydrates in aqueous systems containing two or more hydro-carbon~. Wilcox, Carson and Katz" reviewrd the information on the hydrates of importance in the processing of natural gas and presented data concerning their formation from natural gas. Kobayashi and Katz1' made studies at high pressure of the Hydrate of methane. and Unruh and Katz"' investigated hy-drates in mixtures of carbon rlioxide and methane. Frost and Deaton contributed to the knowledge of the composition of the paraffinic hydrates The irregularities in the experimental results were several times the expected uncertainties. This experience confirms the behavior encountered by other investigators indicating that hydrates tend to occlude water during their formation, thus rendering difficult the direct measoremeut of their composition. Miller and Strong2 investigated a number. of paraffinic hydrates from the standpoint of their possible application to (, the industrial storage of gas. Powel1 studied the effect of solutes upon the decomposition temperature of paraffin hydrates. Marked lowering of the decomposition temperature at a given pressure may he obtained by the use of such additive agents as ethylene glycol, urea. and sodium chloride. APPARATUS AND METHODS Two method* were here employed to study the behavior of hydrates. The first involved a glass capillary within which the hydrocarbons and water were confined over mercury. The second made use of a double-ended weighing bomb technique." The glass capillary equipment has been described elsewhere.'" A schematic drawing of it is presented in Fig. 1, where the arrangement of the agitator and mercury reservoir is shown in some detail. The lower part of the glass capillary, D, was enlarged to afford space within which the fluids used in the investigation could he stored at low pressures after their introduction through the valve. G. The temperature of the capillary was controlled by the circulation of a hydrocarbon oil of low viscosity from the agitated bath, B, through the vacuum jacketed column. C. The pump, A, was employed for the circulation of this oil. A relatively clear view of the capillary tube, D, was obtained through the vacuum jacket. Mercury was introduced into the lower part of the vessel, E, from

Jan 1, 1952

By L. D. Godshall

A great deal has been written of late regarding the loss of silver in assaying; very discordant results have been published by different writers, and much uncertainty exists concerning even approximate losses in a careful determination of silver, as represented by a fire-assay. In the present paper it has been the aim of the writer to determine as accurately as possible the losses sustained by silver, under certain specified conditions, during the process of cupellation. Such losses are well known to be due to absorption by the cupel and volatilization. The conditions, however, which govern these losses are not believed by the writer to be so well understood. The most important of these are : 1. The effect of variable quantities of silver used. 2. The temperature of cupellation. 3. The character and quantity of impurities in the lead button. 4. The weight of the lead button. 5. The nature of the cupel. The following experiments were made for the purpose of demonstrating, as nearly as possible, the total loss of silver in cupellation under the most favorable conditions to be obtained in commercial assaying. Chemically pure silver and pure lead were taken. The latter was obtained from test-lead, first melted into a bar, from which pieces of the desired weight were cut and accurately weighed. The experiments recorded in this paper were planned by the writer, but executed throughout by Mr. J. N. Walker, whose ability as an accurate, careful and painstaking assayer is too well known and recognized throughout the West to require any further endorsement from me.

Jan 1, 1897

For the year ending February, 1919 PRESIDENT SIDNEY J. JENNINGS NEW YORK, N. Y. PAST PRESIDENTS L. D. RICKETTS NEW YORK, N. Y. PHILIP N. MOORE ST. Louis, MO. FIRST VICE-PRESIDENT C. W. GOODALE BUTTE, MONT. TREASURER GEORGE C. STONE, NEW YORK, N. Y. SECRETARY EMERITUS ROSSITER W. RAYMOND, NEW YORK, N. Y. SECRETARY BRADLEY STOUGHTON NEW YORK, N. Y.

Jan 4, 1918

By M. B. Ramachandra Roa

This paper records the results of the earth resistivity surveys made in the Godavari River in connection with the Ramapadasagar project. After describing the topographical and geological features of the area, the results of the investigation at the several sites have been mentioned. Further, a detailed account has been given of the resistivity methods adopted, the apparatus used and the interpretation of the curves. The resistivity measurements carried out over the water course have been specially outlined, and a review of the verification of the electrical indications by drilling in a number of cases, has also been presented. Introduction The Government of Madras has under consideration the Ramapadasagar project which is estimated to cost some Rs.660,-000,000 (about two hundred million dollars). The most essential feature of this project is the construction of a high dam across the Godavari near Polavaram for impounding the waters of this great river of South India, whose maximum discharge is 2 million cu secs in flood time. It is estimated that when the proposed reservoir is constructed, about one million tons of rice could be produced annually under irrigation. To those who have had any acquaintance at all with the recent distressing famine conditions which India has passed through and is still undergoing, the Lounteous effects which this project will bring about to the country in the future, are obvious. In the region of the proposed reservoir, the river flows for several miles through a hilly tract, hemmed in between flanks of hard, solid rock; but the river bed is mostly sandy. A few bore holes put down in this sandy bed touched rock at a depth of 180 to 200 ft. The river bed is about jo ft above the mean sea level (m.s.l.) and the bedrock was found at —125 to —160 ft m.s.l. The crest of the dam is proposed at +162 ft m.s.l. The proposed dam mould therefore be about 120 to 130 ft above the river bed, and the foundations would have to reach down nearly zoo ft below the bed at the deepest part. A number of alternative sites were proposed for investigation, and it became necessary to quickly ascertain the bedrock topography at these sites. Dr. M. S. Krishnan,* who was consulted in the matter, furnished a detailed account of the geological features of the region and suggested a geophysical investigation which the writer carried out from February to April 1944, employing solely the electrical resistivity methods. The total length of the survey lines for the electrical measurements amounted to 62,600 ft and the number of resistivity determinations was about 2500. Altogether nine alignments for the dam were inten-

Jan 1, 1949

By C. F. Smart

SINCE their comparatively recent development, the alloys of cadmium with silver and copper or nickel, and of cadmium with nickel alone, have been used somewhat extensively as liners for connecting rod bearings and main bearings of internal-combustion engines. In applications where, owing to high hearing loads and elevated operating temperatures, the life of hearings made from tin-hale or lead-base alloys has been undesirably short, cadmium alloys have demonstrated considerable advantage. In applications where, because of deflection of the crankshaft or bearing supports, copper-lead bearing metals have resulted in scored shafts, cadmium alloys have been operated successfully. The somewhat serious drawback to these alloys in hearing service has been that they, in common with copper-lead and certain lead alloys, are susceptible to corrosion in the presence of lubricants containing organic acids. These acids may be fatty acids (such as oleic acid) derived from animal or vegetable oils that sometimes have been compounded with engine lubricants, or they may be compounds of an acid nature developed by the oxidation of some petroleum oils under operating conditions. The result of such acid attack on hearings is illustrated by the photograph, Fig. 1. The petroleum oils that are most readily oxidized to a corrosive condition, and the operating conditions under which such oxidation most readily occurs, are now rather well known among the technical organizations of both the petroleum and automotive industries. While means have been developed for inhibiting petroleum oils against such acid formation, the knowledge that this condition may be encountered has been a factor in restricting the wider use of cadmium alloys as engine bearings. It has appeared, therefore, that their value and use would be enhanced if they could be made corrosion-resistant to a degree compatible with the most severe operating requirements. Investigation, undertaken with this in view, indicated that the addition of fractional percentages of the metal indium to the cadmium bearing

Jan 1, 1938

By Marcus A. Grossmann

This paper offers for consideration certain somewhat radical modifications in the iron-carbon diagram, these modifications being the result of the presence of notable amounts of alloying elements. When only small amounts of alloys are present, the standard iron-carbon diagram (Fig. 1) can be used with but insignificant changes; when larger amounts of alloys are present, however, it assumes a distinctly altered appearance. No comment is offered for the present except to call attention to the delta area, A4BM, which represents a region of mixtures of austenite and delta iron, just as area A3SP represents mixtures of austenite and alpha iron. Absence of Carbon We may turn at once to the effect of the presence of alloys. It has been found that in the complete absence of carbon, the gamma change will sometimes disappear entirely when sufficient alloying element is

Jan 1, 1927

By William F. Butler, Mo-Hung Che

DEVELOPMENT OF MONEY AND MONEY STANDARDS This chapter is concerned with the rise, and then the decline and fall, of gold and silver as monetary metals. As a first step in tracing the history of this process, it is necessary to consider the nature of money, and the manner in which different forms of money have developed over the centuries. The origins of money go back into deepest antiquity. Once men ceased to be pure nomads and entered into even a rudimentary form of society such as clans or tribes, money had to be invented The first step was barter as farmers or hunters swapped their surplus products for things produced by artisans such as shoes, clothing, and simple tools. But such barter trading is inconvenient even in primative societies It is difficult to match up buyer and seller at any point in time There are problems in arriving at viable and acceptable terms of exchange. The accumulation of savings-wealth-is complicated. No one can be sure that a pile of furs, or wheat, or certainly fish or game can be used in the future to trade for other goods or services. So even prehistoric man saw the need for money. There was a need first for something to serve as a medium of exchange This was an essential first step in the process of specialization-or the division of labor. A farmer, a hunter, or a shoemaker could only devote his full efforts to his trade if he could be sure that he could exchange his surplus production for the other things he needed for existence. This required a medium of exchange-a form of money which would be broadly acceptable. Money was needed for two other reasons Some system of market prices was essential to facilitate the exchange of goods and services. This required some form of common denominator-some standard of value-to govern the exchange process. And there was also need for something to serve as a store of value, a place to put any excess production (savings) with the assurance that it can be used in the future to acquire a general range of goods and services. As a result, money, in one form or another, developed at a very early state in civilization. Yet the centuries have been marked by a search for a form of money which will possess in full measure all of the attributes in money-a reliable and universally acceptable medium of exchange, standard of value, and store of value. -A wide variety of things have been used as money at one time or another: shells, beads, stones, feather, metals, and even the teeth of sharks and dogs. Some of these things were obviously of little or no practical value. They were used because people had confidence in their continued acceptance as a medium of exchange. As the world evolved and as trading ex-

Jan 1, 1976

By Bruce E. Grant, Thomas Jancic, Lawrence G. Dykers, Frank Buchella

Principal factors influencing equipment selection can be grouped into five basic categories: tonnage requirements, ore and waste; topography and property line considerations; ore control requirements; physical characteristics of ore and waste; and climatic considerations. Loading, transporting and ground preparation equipment are largely determined by tonnage requirements. Large size equipment is appropriate for a production of about six million tpm, medium size for three million tons and small size for one million tons or less.

Jan 12, 1973

As one surveys the extensive taconite operations on the Mesabi Range, he may find it difficult to believe that only 15 years ago, the iron ore mining industry here was staring at its own imminent demise. Due to the high demands for iron ore during World War II the postwar period of 1946-1950, and the subsequent "police action" in Korea, there was rapid consumption of the Mesabi's already depleted ores, and some economists were giving the Range only 20-25 years of life. In the 13-year period 1941-1953, more than 850 million tons of iron ore were shipped to steel mills, an amount almost equal to the total production during the preceding 30 years. Proven ore reserves dropped from 1.1 billion tons in 1940 to 8.3 million tons in 1954, the largest decrease being recorded in the famed direct shipping ores.

Jan 9, 1968

By Sidney Cornell

THE technical- advantages of adding oxygen to air and producer gas, or using it as a reactive agent, producing 400 B.t.u. gas instead of. the present 150 B.t.u., with higher flame temperatures and a reducing flame possible, with a smaller volume of gases passing through a furnace, will result in quicker melting, sharp working, and the production of a higher quality steel. Probably electric-furnace quality steel can be produced in an open-hearth furnace using oxygen. A modern, standard, 100-ton open-hearth furnace, with all equipment, costs from $350,000 to $500,000; there are about 1000 open-hearth furnaces in this country. When considering the use of oxygen in the open-hearth furnace, it is necessary to study: (1) The use of oxygen in the present furnaces, such that modification of existing furnaces and equipment cost the minimum, although the full advantages of oxygen are not thus obtainable. (2) The use of oxygen in a furnace designed for its use, producing quality and quantity steel at the lowest possible cost. This entails the junking of approximately one-half the value in existing equipment-writing off $250,000,000. The basis of such an estimate is the present cost of manufacturing open-hearth steel. Objection may be taken to some of the unit prices here given, but while some companies obtain their ores for much less, the prices quoted are -market price. They are used to show the maximum economy obtained by oxygen at that point.

Jan 11, 1924

By Paul E. Dorr, Kenneth P. Pavlich

This paper covers the practical aspects of economic analysis of mineral ventures and the application of a publicly available computer program. The paper touches briefly on the time value of money concepts and the phases of project evaluation. The most comprehensive port ion of the paper deal s with the requirements for economic evaluation, including capital expenditure categories, operating expenses, required geological and engineering data, and tax considerations. Highlights of the 1981 and 1982 tax laws are covered. A case study using the MINECO computer program will be used to illustrate the economic evaluation concepts developed. Guidelines and goals of sensitivity analysis and Monte Carlo simulation will be discussed and demonstrated on the MINECO example. The MINECO software system will be displayed as an example of a "user-friendly", interactive, and flexible computer tool available to the mining professional today.

Jan 1, 1983

By A. B. Kinzel

Precise knowledge regarding the effect of heat treatment on the properties of steel has made possible the detailed specifications and instructions covering optimum heat-treating temperatures and practices that are in current use. A distinct contrast is presented by the metallurgical treatment of steel adjacent to a fusion weld, as such steel is subjected to each temperature from room temperature to fusion temperature, and cooled at a rate that is not generally controllable but is predetermined by the nature of the assembly to be welded, the kind of welding used, and the surrounding conditions. This is true regardless of the type of fusion welding: oxyacetylene, electric arc, thermit or flash resistance. Therefore it seemed desirable to investigate the effect of this metallurgical treatment on the characteristics of carbon steels commonly used for welding, by a detailed study of metal subjected to each temperature range; i.e., each heat-affected zone. Oxyacetylene welding was chosen for the investigation because of the experimental facility of accurately segregating and studying each temperature zone. The nature of the zones produced by other types of welding is the same. The difference is primarily a matter of dimensions of each of the temperature zones involved. The advantages and disadvantages of the extent of the zone are of prime moment, and are discussed after the presentation of the detailed zone study. No mention is made of the fused metal proper, as this has been the subject of much published research and the nature of the solidified metal is fairly .ell known. General Method The scheme of procedure in the work herein reported involved the testing of the metal of each temperature zone adjacent to the weld in so

Jan 1, 1935

By Henning Nielsen

SIX weeks ahead of schedule, the International Nickel Co. of Canada Ltd. has brought a 30-mile rail line into the newly born town of Thompson, Manitoba. Its construction spurs the development of a rich new mining region slated to become the world's second largest nickel-producing area-exceeded only by Inco's Sudbury, Ont., workings. Two mines, the Thompson and the Moak Lake, will be opened to meet International Nickel's scheduled annual production goal of 385 million lb of refined nickel by 1961. Accomplishment of this aim will mean an additional 75 million lb of the metal available to consumers. In addition, stepped-up out- put of Inco's Sudbury holdings may increase this figure by another 25 million lb. (For an earlier report on these developments see MINING ENGINEERING News, January 1957).

Jan 12, 1957

By A. B. Kinzel

Precise knowledge regarding the effect of heat treatment on the properties of steel has made possible the detailed specifications and instructions covering optimum heat-treating temperatures and practices that are in current use. A distinct contrast is presented by the metallurgical treatment of steel adjacent to a fusion weld, as such steel is subjected to each temperature from room temperature to fusion temperature, and cooled at a rate that is not generally controllable but is predetermined by the nature of the assembly to be welded, the kind of welding used, and the surrounding conditions. This is true regardless of the type of fusion welding: oxyacetylene, electric arc, thermit or flash resistance. Therefore it seemed desirable to investigate the effect of this metallurgical treatment on the characteristics of carbon steels commonly used for welding, by a detailed study of metal subjected to each temperature range; i.e., each heat-affected zone. Oxyacetylene welding was chosen for the investigation because of the experimental facility of accurately segregating and studying each temperature zone. The nature of the zones produced by other types of welding is the same. The difference is primarily a matter of dimensions of each of the temperature zones involved. The advantages and disadvantages of the extent of the zone are of prime moment, and are discussed after the presentation of the detailed zone study. No mention is made of the fused metal proper, as this has been the subject of much published research and the nature of the solidified metal is fairly .ell known. General Method The scheme of procedure in the work herein reported involved the testing of the metal of each temperature zone adjacent to the weld in so

Jan 1, 1935

AT the meeting of the Board of Directors held on June 25, 1926, and in response to numerous in-dividual suggestions for changes, a committee on Re-vision of the Constitution and By-Laws of the Insti-tute was appointed, consisting of C. F. Rand, Archi-bald Douglas and H. Foster Bain. Various confer-ences were held, much correspondence conducted and a preliminary draft was prepared. It proved imprac-ticable to complete the work in time to submit the matter to the membership for approval or disapproval at the annual meeting in 1927, and the Committee was continued with instructions to prepare a report as a basis of action in 1928. After Mr. Rand's death George Otis Smith was appointed in his place and the tentative draft herewith submitted has been pre-pared in its present form by Messrs. Smith, Douglas and Bain, though not differing in any material mat-ter from an earlier draft approved by Mr. Rand. In preparing this the Committee has kept in mind primarily the desirability of simplification and of making the By-Laws conform to the actual practice of the Institute as worked out through experience. The Constitution and By-Laws adopted in 1912, and which with minor amendments only still govern the Insti-tute, are full of specific provisions regarding pro-cedure; such as that laid down for guidance of the Papers and Publications Committee. Many of these have proved unworkable and in practice have not been always strictly followed. It now seems wise to write into the Constitution and By-Laws only the general fun-damental principles to he followed and to provide for such easy change in methods of following them out as will permit efficient conduct of the business. It is this thought that has guided the Committee in rewrit-ing many of the sections. With this in view also the Constitution, as such, has been shortened to the brief-est feasible statement of fundamentals. All matters relating to means of making these principles effec-tive have been put into the By-Laws or in the hands of committees whose work is subject to control and whose rules are subject to approval or disapproval by the Board of Directors. Many suggestions for changes have come to the Committee that have not been incorporated in this draft. Some of these are in themselves excellent but have not been incorporated here because the Commit-tee discovered no sentiment for them such as would be likely to secure their approval, or found them out of harmony with the general plan followed herein.

Jan 9, 1927