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By J. M. Gaines, C. H. Herty

IRon oxide (FeO) plays an extremely important part in the manufacture of steel. In the open-hearth furnace and the Bessemer converter it is the chemically predominant compound and controls to a large extent both the operation of the furnaces and the composition and quality of their products. Almost all of the refining action is carried out through the medium of FeO, which oxidizes carbon, manganese, silicon and phosphorus. At the end of any open-hearth or Bessemer heat the steel contains dissolved iron oxide, which must be wholly or partly eliminated. The type of deoxidation product depends on the amount of dissolved iron oxide and on the deoxidizer used. After the heat has been deoxidized and while it is being teemed, iron oxide diffuses from the ladle slag into the metal, causing losses of deoxidizer and increase in iron oxide content of the steel. It is generally believed that non-metallic inclusions are responsible for a great many failures of steel in service and for decreased yield of steel during rolling. The basis of most non-metallic inclusions is dissolved iron oxide. This investigation was undertaken in order to determine the amount of iron oxide that will dissolve in iron under various conditions. Steel-making slags are complex and it has been thought best to determine solubility under simple slags as a first step. The study is being continued under slags whose compositions approach those of operating slags Previous Investigations The solubility of oxygen in iron has been determined by a number of investigators (see Table 1) but their effort's have been directed toward the

By William M. Baldwin, T. S. Howald, A. W. Ross

EXPLORATORY WORK THE related subjects of preferred orientation, directionality in physical properties, and earing tendencies of wrought metal [ ] strip have attracted the attention of metallurgists to such an extent that in the past 20 years hundreds of researches have been published on this one general problem. The anisotropy of tensile strength and elongation have been exhaustively studied in their relationship to the occurrence of ears in cups drawn from strips-20.29 and, to a lesser extent, yield strength7,11,17 and stress-strain curves" have been investigated. Despite the tremendous fund of knowledge thus accrued, no simple quantitative correlation of directionality and earing tendencies has yet been found. In a sense, this is not surprising. The formation of ears in a drawn cup clearly is a special phase of the general study of metal flow; in particular (as will be brought out in the course of this paper), ears are due to anistropy in the rates of deformation of the metal in the radial, circumferential, and "thickness" directions of the original blank. It would be difficult to effect a correlation between earing tendency and a property that may be completely independent of the flow of metal, or at best related to metal flow in an exceedingly complex fashion. Yet, it is this correlation that has been attempted; tensile strength and elongation are attributes of metal rupture, a phenomenon that has quite admirably been shown to be distinct from the phenomenon of metal flow,21 while yield strength and stress-strain

Jan 1, 1945

By J. T. Mackenzie

HENRY MARION HOWE, in whose memory we are gathered together, was one of the great thinkers who develop from time to time to whom is given the rare gift of synthesis. Analysis is given to few, but synthesis, the ability to show the relation of all parts to each other and thus to give a clear picture of the whole, is reserved for the very few. Analysis can be achieved by honesty, intelligence, and industry, but synthesis is only given to genius Professor Howe's crowning achievement is the picture of the whole iron-carbon series shown in Fig. I, which places steel, malleable, gray iron, mottled and chilled irons in their proper relation to each other and shows the essential unity of the series. Perhaps his best statement of the case is found on page go of the Metallography of Steel and Cast Iron in these words: "Each member of the gray cast-iron series consists of the metallic matrix approximately equivalent to that member of the steel-white-cast-iron series to which it corresponds in percentage of combined carbon with its continuity broken up-by masses of graphite . . . " Apparently he had taken considerable interest in this idea around the turn of the century, for he refers to a discussion at the Franklin Institute in 1900 in which he said: "Though many others had probably conceived this relation between the steels and cast irons, it was here enunciated for the first time, so far as I know. It was received with great incredulity." The concept was explained in some detail in a paper on 'The Constitution of Cast Iron" presented before the A.S.T.M. in 1902 when Professor Howe was retiring president of that young society. In the discussion Dr. Sauveur stated that he was "very well acquainted with Professor Howe's theory of the constitution of cast iron," and went on to say that while he "shared it to the fullest extent, some foundrymen . . . claim cast iron is a metal entirely different from steel . . . that steel and cast iron have very little in common, and that therefore the knowledge gained in the study of steel is of little or no value in the study of cast iron." Dr. Moldenke, in discussing the same paper, said he had been working on the same theory for 12 years but he laid no claim to publication. Discussing the difference in the micro- structure of the metallic matrix, Professor Howe pointed out that "such minor struc- tural differences are indeed to be expected, because of the difference in the conditions under which these constituents are generated. "One difference in these conditions is that the steel of most micrographs has been either forged or at least treated thermally in such a way as to give a new structure radically different from that which formed during the initial solidification, whereas the cast irons have not. Hence what we see in the steels is a transformation structure, but in the cast irons a solidification structure. By giving the cast

Jan 1, 1944

By D. E. Light, J. Y. Somnay

The use of alkyl acid phosphates and their alkali salts as collectors for the uranium minerals brannerite and uranothorite was investigated. In particular a detailed flotation study was carried out using isooctyl acid phosphate as a promoter. Tests were conducted on an Elliot Lake ore analyzing 0.11% U 3 O 8, chiefly as brannerite, and approximately 9% pyrite. Pyrite was floated with conventional reagents; the flotation of brannerite from the sulfide tails was studied to determine the optimum pH and pulp density to employ with isooctyl phosphate. 4 uranium recovery of over 90% was possible with a selectivity index of 8.95 when these tails were floated at 17% solids and a pH of 1.7. The effect of various modifying agents was also investigated. Aluminum sulfate, lactic acid and sodium silicate improved the selectivity of collection yielding selectivity indices of 9.5 to 11.5. Ferric chloride was found to be a depressant for brannerite. A Bancroft ore which analyzed 0.13% U308, and contained uranothorite was also amenable to flotation using isooctyl acid phosphate. The composite uranium concentrate obtained assayed 0.41% U308 at a recovery of 95.3% and a ratio of concentration of 3.24. Previous investigations1,2 on the flotation of brannerite, pitchblende, uraninite and/or uranothorite from various Canadian ores showed that fatty acids, including oleic acid and tall oils, petroleum sulfo-nates and alkyl acid phosphates, were suitable collectors for these uranium minerals. Additional work carried out by the Mines Branch in Ottawa on brannerite ores from the Elliot Lake area3 used the tall oil Acintol FA-1, or FA-2, as a collector. A recovery of 92% of the uranium in a concentrate which contained about 55% of the weight and assayed 0.2% U3O8 was obtained from a feed of 0.1% U308 in this latter instance. Eigeles et a1.4 carried out flotation on pitchblende ores and found that the most promising results were obtained with alkyl acid phosphates and their alkali salts as collectors. Within the homologous series of alkyl phosphates, the best flotation characteristics were displayed by isooctyl phosphates. Further, isooctyl phosphate derivatives were much less sensitive to hardness forming salts than oleic acid, enabling all flotation tests to be made with tap water. This paper describes tests employing alkyl acid phosphates for the flotation of ores containing brannerite and uranothorite. The flotation work described herein was conducted in conjunction with the development of a leaching process for Elliot Lake, Ontario, brannerite ores. In this process pyrite in the ore was concentrated by flotation and roasted, providing sulfur dioxide which was used to produce sulfuric acid in situ in a liquid-solid extraction process. A 40% conversion to sulfuric acid was indicated at a leaching temperature of 80°C; this resulted in the extraction of 93% of the total uranium after a contact period of 6 hr. A rotary kiln was used as a leaching vessel. Preconcentration by flotation was studied in conjunction with the above process to reduce the bulk of solids for leaching and, consequently, capital expenditure. The materials and methods used in this study will be described initially. Then the results will be presented in two sections, the first dealing with the brannerite ore, and the second with the uranothorite. Finally an economic analysis of the results on the brannerite material will be made. MATERIALS AND METHODS The two ore samples examined were from uranium-producing mines. One was a brannerite ore, a uraniferous quartz pebble conglomerate from the Elliot Lake area, which contained 0.11% U3O8, 4.3% S and 4.5% total Fe. Mineralogical studies of similar samples indicated the presence of quartz, microcline, sericite, pyrite and minor quantities of rutile, pyrrho-tite and zircon. The other ore was from a biotite-rich pegmatite in the Bancroft area; feldspar, quartz and biotite formed the major gangue components. Uranothorite was the principal uranium mineral; the head assay was 0.13% U 3 O 8. Preparation of Feed: The ores were crushed to —10

Jan 1, 1963

By F. H. Labee

Questionnaires and special letters soliciting information were sent to a great many geologists, petroleum engineers, independent operators, and representatives of large companies in Arkansas, Louisiana, Texas and New Mexico. Replies to more than 50 per cent. of these letters were received. A survey of the facts and opinions presented in this correspondence will be made a little later, but first some of the general aspects of the problem will be reviewed. By "unit operation,"1 we mean the development and operation of a single entire pool, or reservoir, of petroleum by one management, on a systematic and scientific plan which is best calculated ultimately to extract from the pay sand and bring to the surface of the ground the largest possible amount of oil with the greatest possible total profit. No one, as far as the author has been able to ascertain, denies the advantages, both scientific and practical, of unit operation. All are agreed that it is sound in theory. It permits the proper distribution of wells, which should always be spaced on the ground according to a regular geometric plan with the intention of maintaining the same spacing all the way down and into the pay sand, or pay sands. This spacing will be different for different fields, depending on such variable factors as the lithologic character of the pay formation, the nature of the controlling structure, the depth of drilling, the viscosity of the oil, and so on. From the viewpoint of engineering practice, as applied to economical extraction of oil, there is no more important consideration than well spacing—well spacing in the pay formation, and not merely on the surface of the ground —for the method of well spacing has a direct bearing upon all such engineering practices as pressure control, repressuring by gas, the water drive, and SO on. H. C. Miller2 summarized the advantages of an ideal cooperative development plan as follows: "Among the more important advantages of

Jan 1, 1930

By W. E. Wrather

The overproduction of crude oil in 1927 has received such widespread publicity, both within and without the industry, and the several factors which have brought about this situation are so thoroughly agreed upon by everyone, that it is unlikely the writer will in this brief review be able to contribute anything new. The entire story of low prices and demoralization revolves around two flush districts, Seminole and West Texas— the actual. performance of Seminole and the potential threat of West, Texas. The sustained production of California has been a contributing factor to this situation also. It seems reasonably certain that Seminole and West Texas will together dominate the industry during 1928, with Seminole probably destined to drop into second place, as additional pipe lines are completed into West Texas to care for its rapidly expanding production. It now appears inevitable that the production of 1928 will equal or exceed that of the past year, depending solely upon the rapidity wit,h which it is possible to market West Texas crude, and the degree of restraint which operators are willing to impose upon themselves in holding proved reserves of oil underground. Adversity has cultivated the growth of a promising spirit of cooperation which has accomplished practical results both at Seminole and in West Texas. Cooperation among oil producers has long been ardently hoped for, but prior to the past year it has never been effective on an important scale. The interests both of the industry and the public at large can best be conserved by cooperation in controlling production, and the widespread acceptance of this idea has paved the way for a more rational policy in the immediate future Production BY Major Districts The domestic production of the United States during 1927 amounted to 894,43.5,000 bbl. (Bureau of Mines), an increase over 1926 of approximately 128,000,000 bbl. California succeeded in maintaining its position of the past four years at 230,000,000 hbl. In 1923 with the Los Angeles

Jan 1, 1928

By John B. Pearse

IN order to get an idea as to the strength of steel rails, it will be well to review the tests to which iron rails have been subjected. In England, Mr. Ashcroft found that the best 80 pound rails broke under a 300 pound weight, falling 15 feet. In Germany the Society of Railway tyfanage1-s determined 011 and have long applied a test of 1000 pounds falling 101/2 feet, as the standard which all first-class iron rails must reach. In this country no inspection nor test is applied, but tests made show that iron rails fro; our most reliable makers, break under a G foot fall of a 1500 pound drop as an extreme test, most of those tested breaking under a far less test; some breaking with less than a 3 foot fall of the same weight. Everywhere where steel has been used, engineers have come to the conclusion that some test is required to show the regularity and strength of the product. As compared with iron, the tests which steel will stand are wonderful. After numerous experiments partially based on the experience of the rail-mill at Graz, belonging to the Southern Railway of Austria, the Society of German Railway Managers fixed upon a test of 2000 pounds falling 138 feet. They found that this test represented the steel which suited their necessities, and also found that with steel of otherwise average purity, this test represented about one-half per cent. of carbon, and made it a rule to take no steel containing under three-tenths of a per cent. of carbon, because it was too soft. They expressed a hope that a harder steel could soon be made tough enough to stand the same test. I n England, a test was adopted of 2240 pounds, falling 15 to 17 feet on the rail on heavy bearings. This test has been found satisfactory under heavy traffic on average road-beds, and has been invariably

By Earl C. Henry

Magnetic iron ore was mined in Essex County, N. Y., during the American Revolution; Benedict Arnold is said to have mined ore near Port Henry to secure iron for chains and spikes for the Lake Champlain fleet. Details regarding the operations prior to 1804 are not easily obtained but work on a commercial scale appears to have been started about 1838. The Witherbee, Sherman & Co. was established in 1849. The property of the district is held in fee almost entirely by the mining companies. The Mineville iron-ore district, as well as the entire Adirondack region, belongs to the pre-Cambrian complex. The readily identified rocks consist of gabbro, anorthosite, syenite, and granite, and are classed as igneous, eruptive, and intrusive. In addition, there is a great variety of gneisses, rocks with a variable mineral composition but all more or less distinctly foliated. The Grenville series are the oldest rocks in the district; this series consists of graphitic white limestones, graphitic sandstones, and quartzites and gneisses with or without graphite. The orebodies occur in the gneissic rocks and are comformable to the structure of the rocks. The typical occurrence of the ore in this district is in lenticular bodies with a parallel pitch to the southwest; this structure is best exemplified in the New Bed mine. The Harmony and Old Bed orebodies are faulted by two sets of diabase dikes, one set having a southwest strike and the other set an east-west strike. The ores occurring in the acid gneissic rocks are non-titaniferous. The ores occurring in the gabbros and anorthosites are high in titanium; these deposits are irregular, have no structural relation with one another, and are unquestionably of igneous origin. The origin of the gneissic rocks and the ores therein contained is not settled; both the sedimentary theory of ore concentration and the igneous theory of magmatic segregation have been advanced. The iron mineral in all the orebodies is crystalline magnetite; some very perfect and large specimens have been obtained. The gangue is

Jan 1, 1925

By Robert B. Sosman

THE relative temperature distribution within a coke oven and among the ovens in a battery can be obtained automatically for the operator's guidance by sighting a total-radiation pyrometer on the face of the coke as it is pushed out, and recording the surface temperature. Keeping the instrument clean and keeping its view of the coke unobstructed by smoke and dust are the principal problems. Typical records from three plants are presented in this paper, showing that the temperature patterns are reproducible. DEVELOPMENT OF METHOD The method of coke pyrometry described in this paper was introduced in 1936 by E. A. Lee, then Assistant Superintendent, now Superintendent, of the Coke Plant at Lorain Works, National Tube Co., Lorain, Ohio. At the request of the Coke Committee of the United States Steel Corporation, the Research Laboratory of the Corporation undertook to adapt the method to the somewhat different conditions met with at the Gary Works of the Carnegie-Illinois Steel Corporation, Gary, Ind., and at the Clairton Works of the same Corporation at Clairton, Pa. This work was done in cooperation with the Leeds and Northrup Co. of Philadelphia and later with the Brown Instrument Co. Division of Minneapolis-Honeywell Regulator Co., Philadelphia. We of the Research Laboratory wish to express our appreciation of the courtesies extended by Mr. Lee, by A. N. Cole, Superintendent of the Gary coke plant, and by D. P. Finney, Assistant General Superintendent in charge of coke-plant operations at Clairton. We are also indebted to the instrument companies for the loan of a part of the equipment. At Gary and Clairton the instruments were installed and various experiments were made by J. W. Bain, of the Research Laboratory of the United States Steel Corporation. PYROMETRY OF COKE The coke inside a by-product oven is almost completely inaccessible to pyrometric instruments. The temperature in the walls can conceivably be measured with thermocouples, but the atmosphere is usually strongly reducing, a condition well known to be destructive to the accuracy of the customary high-temperature couples. In some plants, periodic readings are taken with an optical pyrometer sighted into the top of the combustion flues. This is a useful measure for safety and general control, as it tends to prevent the damage that would result from overheating of the ovens. It does not, however, tell much about the temperature of the coke itself, because of the continually changing gradient in the wall between the coke and the combustion chamber. The best indication of the temperature of the coke itself must therefore be obtained by observation of the product as it is pushed out of the oven. The human eye is very sensitive to variations in brightness of a surface, and particularly to differences in brightness over a continuous hot surface.

Jan 1, 1942

By K. S. Benson

DEPLETION is a subject of vital importance to the mining industry. Yet, in spite of its importance, its significance is not generally understood. The purpose of this discussion is to clarify the main aspects of the subject from the viewpoint of a metal mine taxpayer. To define the term depletion, it is necessary to distinguish among its various uses. In the economic or geological sense, depletion means the exhaustion of a natural resource. A mineral deposit is a wasting asset and once exhausted is nonrenewable. Millions of years were needed to produce an ore deposit, which may be consumed in a few years and which cannot be replaced except by the discovery of new sources of supply. The wasting asset feature of the mining industry has a vital bearing on the impact of the Federal Income Tax Law on this industry. This is recognized in the law by the various provisions dealing with the depletion allowance, and in this sense the term depletion has an income tax meaning. Depletion from the tax viewpoint means the statutory deduction from gross income designed to permit the return to the taxpayer of the capital consumed in the production and sale of a natural resource. The mining enterprise realizes income on the extraction and sale of minerals and a portion of the income realized represents capital consumed. As the resource is exhausted, the mining enterprise approaches the end of its existence unless new sources of supply can be acquired. Depletion from the tax viewpoint is a creature of statute with limited meaning and application and, in essence, is a method for amortizing the value of the primary asset of a mining enterprise. An example can best illustrate the significance of depletion from the tax viewpoint. Compare a manufacturing concern with a mining company. In computing taxable income of a manufacturing concern, consideraion is given to the cost of producing such income, the principal costs being capital investment for plant and equipment, labor, and raw materials going into the products produced. A mining enterprise, on the other hand, is faced with a different problem because its principal asset is the natural resource which it is producing. In computing its taxable income, consideration is given also to its capital investment for plant and equipment and the cost of labor; but in addition, recognition must be given to the fact that a portion of the proceeds realized on the sale of mineral represents capital. Without such recognition, the mining company would be taxed not on income but on capital and income, and Congress has never intended that capital be taxed as income. Thus, when depletion allowable is referred to in the mining industry, it means the statutory deduction allowable in computing taxable income of a mining enterprise. For guidance the appropriate provisions of the Internal Revenue Code, Income Tax Regulations, and the judicial decisions interpreting and construing them must be examined. It is important to identify and distinguish three methods of determining the allowance for depletion: 1—Cost depletion, 2—Discovery depletion, and 3—Percentage depletion. The basic method is cost depletion and in addition some taxpayers may be entitled to use discovery depletion and other taxpayers may be entitled to use percentage depletion. Discovery depletion and percentage depletion, however, are mutually exclusive and if a taxpayer is entitled to percentage depletion, he is not entitled to discovery depletion. By statute, a metal mine taxpayer is entitled to use cost depletion or percentage depletion, whichever produces the highest deduction. Thus, discovery depletion is merely of academic interest to such taxpayers and to most others. Briefly and broadly speaking, these methods of determining depletion may be described as follows: 1—Cost Depletion: Under this method, the allowable deduction for depletion is based upon the cost of the particular deposit to the taxpayer, unless the deposit was owned prior to Mar. 1, 1913, in which case the taxpayer may use the fair market value of the deposit on that date or actual cost, whichever is higher. This method is sometimes described as basis depletion or adjusted basis depletion, but in this discussion it will be referred to as cost depletion. 2—Discovery Depletion: Under this method, the allowable deduction for depletion is based on the fair market value of the deposit at the date of discovery or within 30 days thereafter and was originally designed to take into account deposits discovered subsequent to Feb. 28, 1913. 3—Percentage Depletion: Under this method, the allowable deduction for depletion is based on a specified percentage of the income realized during the taxable year from a particular property. As stated, the concept of depletion is based upon the exhaustion of a natural resource as distinguished, for example, from the concept of depreciation based on the exhaustion of property used in trade or business. From the tax viewpoint, depletion first became important in the administration of the Corporation Tax Act of 1909, which provided for an excise tax on net income. As soon as this act went into effect, mining taxpayers attempted to claim a deduction for depletion in computing net income although there was no specific mention of a deduction for depletion in the statute. The courts in these cases uniformly held that the statute did not permit an allowance for depletion in computing net income and also held that the provision permitting a reasonable allowance for depreciation did not include depletion. These early cases are quite significant because they establish the principle that the

Jan 1, 1952

By E. Buehler, R. H. Willens

A Hew melting technique has hem adapted to the rapid quenching of- alloys from the liquid state. The inelting method has no limitations on the alloys investigated for there is no reaction with crucible materials and the most refractory materials are easily melted. The vate of heating is so rapid that alloys which have a high vapor pressure constituent can be melted with a minimal loss in material. Several new superconductovs have been discoveved by vapid quenching of lolten alloys. THE rapid quenching of alloys from the liquid state has led to the discovery of many new metastable phases. The methods initially used were limited to alloys which did not react with crucible materials.1,2 There was also the unmentioned limitation in tem- perature. Alloys with melting points much greater than 2000°C could not be melted in the rapid-quench apparatus. Recently, there have been successful attempts to rapidly quench reactive alloys by Moss et at. and Matthias Moss et al. injected powdered material (325 mesh) into a high-temperature plasma and the high-velocity molten droplets impinged on a cooled copper plate. The technique innovated by Matthias was to melt the alloy in an arc furnace and splatter it against a copper plate by means of a high-velocity gas jet aimed at the melt. I) FAST COOLING APPARATUS The creation of a metastable phase in a given alloy system by rapid cooling from the melt is contingent on the quenching rate. Some alloys require very slow rates while other alloys require the ultimate in quenching rate. At the present time, the vertical-gun technique of Duwez and willens' has demonstrated, in practice, the highest quenching rates and thus the best

Jan 1, 1967

C. W. GOODALE, Butte, Mont. (member of the committee)- (communication to the Secretary*).-In the discussion of papers presented at the New York meeting of the Institute in February, 1915, and at the Arizona meeting of September, 1916, I referred to the activities of the Bureau of Safety of the Anaconda Copper Mining Co., and I am now submitting a few thoughts by members of the staff of that Bureau. TORGUS H. OAAS, Safety Engineer, Butte, Mont.-The report of the Committee on Safety and Sanitation has described different organizations and methods of promoting safety work. The effectiveness of these methods would aid the beginner in his campaign for safety in choosing the kind of organization and methods best adapted for his field. This can he obtained only by a discussion by those who have long promoted this kind of work, and have met with successful results. As the field is new, the different organizations promoting safety work have not established a common basis of rating for their fatal, serious and slight accidents, so that it is now difficult to get a comparative basis from which to judge the merits of the different systems. C. W. GOODALE.-The U. S. Bureau of Mines adopted, at the beginning, as a basis for its yearly summaries, the number of accidents. per 1,000 men employed, and it is now (quoting from its report for 1915, Technical Paper 168) making the following "classification of injuries:" "Many of the States now have. compensation laws, and in order to conform with their classifications, the bureau's classification of serious and slight injuries for 1915 is on a 14-day (2-week) basis instead of 20 days, as in previous years. The new classification of injuries includes three types, as follows: 1. Fatal 2. Serious (time lost, more than 14 days) (a) Permanent disability Total Partial

Jan 6, 1917

By Sunder S. Saluja

Man had to learn to break rocks as early as the Stone Age, when they formed his main source of raw material. He started with chipping and over the years has reached a stage where he can employ atomic blasts and break, with one blast, millions of tons of rock. In between these two extremes there have been several stages of development including firesetting, use of the expansion of water on freezing in chipped cracks in cold climates, the use of low or deflagrating explosive black powder in about the 17th century, the use of high explosives with the discovery of nitroglycerine in 1846 by Sobrero, followed by the monumental discoveries of the great Swedish scientist Alfred Nobel in the latter half of the nineteenth century. The attempts to develop a stronger and still stronger explosive force were accompanied by investigations to understand the mechanism of failure of rock so that the force could be used to the best advantage; the latter, of course, have lagged far behind the former. This is mainly due to the fact that the chemical reactions involving high explosives as well as the processes resulting in the breakage of rock take place at too great a rate to be studied with the equipment that has been only recently available. Moreover, the development of stronger explosive forces was prompted by military necessities in the past and competition, at present, among highly developed nations. With the development, however, of the new techniques such as micro- second photography, microsecond flash radiography, extremely high-speed movies, strain gage assemblies, electronic chronographs and other improved electronic techniques, the investigator has in the last decade or

Jan 1, 1968

By Richard E. Chism

SAN DIMAS, in the State of Durango, Mexico, on the frontier of the State of Sinaloa, is the centre of an extensive and rich mining region, which has been exploited for over a hundred years; and the patio process for working silver ores has there attained the highest perfection of which it is capable. Local modifications have been engrafted upon the underlying principles of the process, but, as a whole, the San Dimas practice so fully illustrates its typical capabilities, that I have undertaken to describe its workings in the hope of lightening, to some degree, the labors of my professional brethren who may have occasion to visit Mexico." As is tolerably well known, the patio process, like all other systems of free amalgamation, is not successful with ores containing more than a trace of zinc or lead, the presence of zincblende being especially obnoxious. Iron and copper in small quantities are not particularly disadvantageous. The process succeeds very well with all sulphide ores which do not contain much more than a trace of arsenic and antimony, provided the tailings are concentrated, although, of course, it is best adapted for free milling ores. For suitable silver ores that contain small amounts of free gold the process is still a good one, but where the gold is combined with sulphurets, a considerable and even an excessive loss is inevitable. Hitherto the Mexicans have submitted to this loss, but, since the introduction of American mills, they are gradually abandoning the patio process in favor of the other. The San Dimas ores have a gangue of quartz and feldspar. They are composed principally of silver sulphides, with some chloride and

Jan 1, 1883

By Peter Q. Nyce

Law is as old as civilization. In its early stages the so-called law of the jungle, "the survival of the fittest," was entirely operative. Man was quite largely a law unto himself and was likewise his own lawyer. As civilization developed and individuals segregated themselves into bands or communities, man-made laws became a reality, the individual sacrificing certain privileges for the benefit of the band or community in which he was privileged to live. Our present system of law is a continued development of that process. Very early in this development the exigencies of the occasion called into being classes of individuals who were given to study the laws then existing, and this group became known as lawyers. They advised what could or could not be done under existing laws. They were the aggressors in formulating new laws and principles under which the communities must live. Concurrently with the development of the law and the lawyer, the engineering profession was born. In our early civilization, each man was his own engineer; he built his own home, constructed his own bridge, and provided his own means of conveyance. As civilization became more complex, technical study was required to consummate projects and thus meet the requirements of an expanding community. The engineering profession assumed this burden. Both groups were human and thus susceptible to human mistakes and errors. It was Macaulay who said: "The world generally gives its admiration not to the man who does what nobody else ever attempts to do, but to the man who does best what multitudes do well." BiRth of Petroleum Industry In 1859, by the completion of the Drake well in Pennsylvania, the petroleum industry as we know it was born. Its rapid progress since that time has been both extraordinary and remarkable. The zeal of the individual operator to secure all possible oil in the shortest time, even to the extent of bringing into possession a part of the oil underlying a neighbor's property, developed unnecessary drilling, wasteful methods of recovery, great loss of gas, the early abandonment of property with much unrecovered oil thereunder. Such methods, plus

Jan 1, 1931

By Jonas Svensson

A new method is described for the production of cold-bonded pellets using a hydraulic binder, such as portland cement. Large-scale pilot-plant tests have proved that self-fluxing pellets of high reducibility and good handling strength can be made by the method. Blast-furnace trials have shown that the pellets are an acceptable burden material, comparable with self-fluxing sinter or heat-hardened pellets. Economic factors of commercial-scale production are discussed. The Grangcold Pellet Process—for which patents have been applied or already granted in a number of coun-tries—uses a hydraulic adhesive such as portland cement, slag cements, pozzolanic cements, etc., for the production of cold-bonded pellets. The idea of using a hydraulic binder for the agglomeration of iron-ore fines is not new. Portland cement was proposed as an adhesive for cold-bonded iron-ore briquettes in patents granted more than 50 years ago.' In a report on the briquetting of iron-ore fines, published in Stahl und Eisen in 1959; it is stated that briquettes bonded with portland cement are used on a small scale at an ironwork in Germany. According to the report, the briquettes showed excellent strength in the blast furnace although their general use was made impossible because they required a long hardening time, during which they are sticky, soft, and difficult to store and handle. The Grangcold Pellet Process has overcome this particular disadvantage by mixing the balls with a suitable amount of the balling concentrate before storing them. The pellets are embedded in the concentrated during storing in such a way that they are isolated from each other and thus prevented from sticking together to form clusters. Thanks to the embedding concentrate, the pellets are subjected to a more or less uniform pressure from all sides which does not deform them. Thus, the mixture can be stored in a stockpile or in a bin until the pellets have hardened sufficiently. The concentrate is separated from the pellets by means of screening. The concentrate is returned to the balling operation and the pellets are either shipped to the blast furnace or stored for final hardening. The binder preferred for the Grangcold Pellett Process is portland-cement clinker, ground without the admixture of gypsum in order to avoid sulfur in the pellets as far as possible. Usually a 10% binder content is used. Two-thirds of the portland-cement clinker consist of lime and the rest is silica, alumina, and ferric oxide. Thus, self-fluxing or overbasic pellets are produced with this binder if the amount of silica in the concentrate used does not exceed 4%. The Grangcold Pellet Process was developed by the mineral Processing Laboratory of the Granges Co. Work started in 1963 with batch-scale tests. In 1966, a small pilot plant was put into operation in which 1800 tons of pellets were produced using 10% of rapid-hardening portland cement as a binder. Favorable results from a blast-furnace test with this batch led to the decision to erect a larger pilot plant which went into production in the summer of 1967. Since then, approximately 100,000 tons of cold-bonded pellets have been produced, mostly with 10% gypsum-free portland cement as a binder. Several full-scale blast-furnace trials have been performed with the pellets. The results of the trials indicate that the Grangcold pellets constitute a satisfactory blast-furnace feed. An industrial plant for the production of Grangcold pellets with a rated capacity of 1.5 million tpy is now under construction at the Granges Co.'s mine at Grangesberg. The plant will come into operation in the summer of 1970. Results from Laboratory Work Pellets made from iron-ore concentrate bonded with portland cement harden slowly and their handling is very critical until they have hardened enough to loose their stickiness. It is therefore especially important to study the progress of the hardening action and the factors influencing it. This is best achieved by investigating the relationship between the compressive strength of the cement-bonded pellets and the curing time under varied conditions. The general course of this relation-

Jan 1, 1971

The Year Book of the Institute is mailed with this Bulletin. Its membership lists, both alphabetic and geographic, are corrected to Jan. 1, 1918, but its list of officers is revised inn accordance with the elections in February, 1918. The amendment to the Constitution, relating, to qualifications for membership, adopted at the same time, is also inserted in its proper place. We would call attention to the Honor Roll, heading the list of membership. This includes the names of those whom we know (in February, 1918) to be on active military duty, as well as those who are rendering emergency service to the Government in other branches. We are aware that the list is not complete, and shall be grateful for information as to any omissions or corrections. Because of the rapid movement of the military members, their addresses have been omitted from the alphabetic list. Mail addressed to such members, and sent to the office of the Institute, will be forwarded to the best of our information at the time.

Jan 3, 1918

S. F. EMMONS RESEARCH FELLOWSHIP. The movement was started by a number of the friends and admirers of the late S. F. Emmons, Economic Geologist of the United States Geological Survey, to perpetuate his name through a fellowship to be known as the " S. F. Emmons Research Fellowship," and they have succeeded in raising some $13,000 for the purpose of carrying on research work in economic geology. The Committee in charge of this Memorial Fund has succeeded in obtaining the co-operation of Professors Kemp, of Columbia, Irving, of Yale, and Lindgren, of Massachusetts Institute of Technology, in the administration of this fellowship. These three gentlemen are respectively geologists of the institutions mentioned and are exceptionally qualified to determine in what direction the fund can be best administered. It is hoped that additional contributions will be forthcoming from many who have heard of this movement. Subscriptions are invited and may be sent to any one of these gentlemen, or to Benjamin B. Lawrence, Treasurer, No. 60 Wall Street, New York City.

Jan 11, 1913

Report of the Americanization Society, New York Section During the past two months the Americanization Committee has held social meetings of various kinds for foreign-born women, as a preliminary to future effort along the lines of Americanization work. At the same time, a thorough investigation was made as to the work being done in New York by organizations devoted to this interest. The committee will be very glad to help any other committees being formed, in mining centers, with advice and information that has been gathered together as to classes and meetings of all kinds best suited to the needs of a foreign-born population. The work has been so extensively taken up in New York that for the present it would seem to be, for this committee, the most profitable and interesting work to continue the social meetings and to undertake the care of one or more immigrant families, to be friend and adviser in joy and sorrow, work and play, and in this way do some fundamental Americanization work. Respectfully submitted, LAURA G. BURGER, Chairman.

Jan 6, 1918

By P. Barnes

IF it be admitted that the use of the metric system of measurement is desirable, and that it will be well, as urged by one of our engineering societies, to show upon all our plans or drawings a metric scale in addition to a scale of inches, then it becomes important to introduce some ready means of drawing these scales. For many present purposes it is quite sufficient to space off and to draw them with the common dividers and the right-line pen, but if the number of drawings made or copied in an engineer's office, and upon which scales must be shown, is more than two or three daily, then some more mechanical or automatic means should be provided. For a great majority of detail drawings, a simple transcript of the surface of a good two-foot rule would answer every purpose, and probably the best comparative showing of the metric scale would be made by drawing a line of millimeters close by the side of the line of sixteenths. This would be in fact little more than the

Jan 1, 1877