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By J. B. Austin

IN developing a consistent picture of the thermal expansion of the commercial chromium steels, which cover a range of carbon contents, it is desirable to know the expansion in the limiting case of the binary, carbon-free, iron-chromium alloys. We have, therefore, determined the thermal expansion of a series of five special alloys, ranging in chromium content from 3 to 10.5 per cent, with not more than 0.03 per cent carbon, over a temperature range extending beyond the transformation region; this low carbon content enables us to draw reasonably reliable conclusions as to the behavior of the carbon-free system. Moreover, the measure-ments serve to determine the beginning and the end of the alpha-gamma transformation; and they emphasize once more the fact that a transforma-tion temperature determined by any method in which the specimen is cooled at an appreciable rate is apt to be seriously in error, particularly if the metal contains a transformation-retarding element such as chro-mium or managanese. The lag, or undercooling, observed at the ? - a transformation is explained in terms of the influence of temperature on transformation velocity; the rather unusual shape of the ? loop is attributed to a change with temperature and with composition of the distribution of chromium between the alpha-iron and gamma-iron solid solutions. The exact composition of the alloys which were obtained through the courtesy of Dr. W. Rohn, of the Heraeus Vakuumschmelze A-G., is given in Table 1. Determinations of the linear thermal expansion and of transformation temperature were carried out in the vacuum dila-tometer previously described,1 using a rate of heating and of cooling of 3.0° to 3.5° per minute unless otherwise stated. Magnetic susceptibility, which was measured in studying the rate of transformation, was determined with a magnetic balance, which also has been described.2

Jan 1, 1935

By James A. Soles

Concrete is a complex, multicomponent mass whose stability is dependent on three principal variables: quality of the mix, its composition, and environment of the site. The aggregate is only one component, but its constituent minerals may react in unfavorable regimes and, given sufficient time, destroy the concrete. Therefore, besides ensuring that a concrete will meet the strength requirements of a structure, the concrete engineer must be confident that the mortar and aggregates will resist destructive processes. This paper reviews the principal causes and effects of aggregate instability, notes reactions of certain phases, and suggests precautionary measures that can be taken to extend the useful life of concrete structures.

Jan 1, 1984

By R. L. Slobod, B. H. Caudle, R. A. Erickson

In predicting the sweepout pattern efficiency to be expected in a .secondary recovery operation, the reservoir engineer is often confronted with a situation in which part of the producing formation lies between the last row of wells and the reservoir boundary. To date, there has been little or no reference in the literalure to sweepout pattern efficiencies in such areas. This paper presents the results, of a laboratory study in which the area contacted around the edge of a reservoir injected in a five-spot pattern was determined. The X-ray shadowgraph technique was used in this study. It was found that surprisingly large portions of the reservoir area lying outside the well network are conracted by the injected fluid before, abndonment conditions are reached. In fact, it can he said that at least 00 per cent of the circa lying outside the last row of wells and within a distance of one well spacing of these wells will ultimately be contacted by the injected fluid in the case of most water floods. Frorn the results given in this paper, it is possible to estitilate not only the extent to which encroachment into these areas will occur but also the injection volume necessary to produce the wells to abnndonment conditions. INTRODUCTION While considerable work has hern done in recent years1.?.'.''.' evaluating the fraction of the reservoir contacted as a function of the mobility ratio for several different well patterns, there has been practically no mention of what happens to the oil in that portion of the reservoir which lies between the last row of wells and the reservoir boundary. In fact, the assumption is generally made that little or no recovery can he expected From this area. This assumption is incorrect and in many cases will lead to seriouq errors in calculating reservoir performance. The fraction of the area outside the regular well pattern contacted in a five-spot injection system has been studied using the X-ray technique5 to follow the progress of actual floods in porous models of reservoir elemental areas. In this paper, the method for carrying out such a study and the results showing the fraction of the area in question swept as a function of mobility ratio and the produced fluids are presented. THE REPRESENTATION OF A RESERVOIR BY ITS ELEMENTAL AREAS She portion of the reservoir lying between the edge of a reservoir and a line connecting the outermost wells may be roughly designated as the part of the reservoir outside the regular well pattern. An example of such an area is shown as the shaded portion in Fig. 1. The case of a square reservoir utilizing a five-spot injection program and with one full well spacing between the outermost wells and the boundary (Fig. 1) was selected as the single example which would provide the most insight into

Jan 1, 1956

By Guy R. Johnson

It is now generally acknowledged that the successful management of a modern foundry necessarily embraces a knowledge of chemistry, and especially a thorough acquaintance with the effect of the various metalloids on cast-iron, in order to

Jan 1, 1897

By F. H. Deily, H. W. Lownie, E. A. Loria, L. W. Ledgerwood, M. W. 207-000-000-012 Mallett, J. E. Eckel

MANY investigations have been made of the residual gas content of iron and steel. Very few, if any, quantitative measurements have been made on the oxygen content of cupola-melted iron.' The fact that cast iron is a complex alloy rather than

Jan 1, 1957

By J. E. Norton

Production statistics show that during the period of emergence from the depression the coal industry was becoming increasingly cognizant of the economic and competitive necessity for mechanizing. About 1935 many of its leaders were becoming aware also of the alarming scarcity of men properly trained to cope with the new problems of mechanization. In order to get a factual statement of this problem, a special AIME Coal Division Committee was requested to survey the condition. Its investigation disclosed that graduates of mining schools going into coal mining numbered 16 in 1937 and 15 in 1938. With this as a background, Pittsburgh Coal Co. foresaw that a comprehensive program was necessary if it was to enlist the services of trained technical men, who were an indispensable part of a mechanization program. The purpose of this paper is to review the program set up, to comment on the successes and failures and to outline the future course of action. Summer Work An inescapable conclusion from the mechanization statistics was that the opportunities in coal mining were good. Not only was there a void in technical skill to fill from past years, but the accelerating rate of mechanization indicated an increasing demand for technically trained men for the future. The remedy lay primarily in presenting facts con cerning the coal industry to the undergraduate engineers before they made their professional occupational choice. Based on this idea, one of the key points in the program was summer vacation work for the undergraduate, which, through the inducement of summer earnings, brought men into the mines to take a look at the prospects. This was more successful than statistics indicate because the war scrambled badly the orderly working of the program, but it could not obscure the value of a summer work program. A decided advantage was that it gave the company a preview of the graduate. An observation on this part of the program is that it is extremely hard to gauge lower classmen, and we found it wise to give them the benefit of the doubt, as the last two years in college bring about surprisingly rapid development in some men. We could readily single out the men at the opposite ends of the scale of competence. Comprehensive Training Program Having adopted summer work as a means of interesting undergraduates, the Location Weeks Introduction............................... I Underground mining operations............... 27 Coal preparation............................ 24 Inspection—safety, mech., prep............... 31 Mine engineering and survey................. 16 Industrial relations.......................... 12 Operating staff—costs, time study............. 8 Miscellaneous............................... I Total.................................... 120 problem of attracting graduates was met by establishing a training program that covered approximately 120 weeks and

Jan 1, 1949

By J. David Lowell

On a low desert ridge six miles south of Cairo lie the remains of the world's earliest known mining town, Maadi of predynastic Egypt. Copper artifacts, including ingots and an ax head which was spoiled in casting, indicate that copper ore was smelted in Maadi, and radio- carbon dating has placed the activity at least as early as 3300 B.C. This is the oldest documented date for the use of smelted copper, the first industrial metal used by man. Copper was mined and smelted almost as early in Asia Minor and on the island of Cyprus, but the greatest development of the budding copper industry was in Egypt, where specific historical records show that about 10,000 tons of copper metal were produced in the period from 1850-1580 B.C. Contrast this production of 35 tons per year with the present world production of about 7 million tpy.

Jan 1, 1970

CHARLES SCHUCHERT,* New Haven, Conn. (written discussion?).- I embrace ace the opportunity to take part in a discussion of Mr. Woodruff's paper because a successful discerning of what actually constitutes pet-roliferous areas from the geologists' standpoint is worthy of our endeavors, not only from the intellectual side, but also because it may lead, as Mr. Woodruff hopes, to the more certain establishment of principles that can be applied to other continents in exploiting them for petroleum. This discussion will also embrace the results of two other recent papers, one by Alexander W. McCoy and one by Maurice G. Mehl.1 Sources of Petroleum.-Mr. Woodruff is agreed that petroleum comes from plants and animals, or possibly from both, and that it has ac-cumulated by migration into reservoir rocks. These reservoir rocks must of course be porous to become catch basins for the oil and gas, and then, too, their present structures are variable, as they occur in anticlines, domes, terraces, etc. , The structures, he states, are more widespread than are the oil pools, and the same is true for the reservoir rocks. Accordingly, there must be many good sands and structures

Jan 11, 1919

By R. B. Tippin

Laboratory and pilot plant studies showed that supergrade iron ore concentrates (containing less than 2% SiO2) can be made from standard grade magnetic iron ore products by cationic silica flotation. Continuous tests were run using various flowsheet arrangements. whereby (1) super and standard grade products were made simultaneously or (2) only a superconcentrate was produced. After a caustic scrub and desliming pretreatment, the silica in a magnetic taconite concentrate was reduced to 1.8% SiO2 by amine flotation. Approximately 75% of the iron was recovered in the single flotation stage, and by additional beneficiation 95% of the total iron was ultimately recovered,

Jan 1, 1973

What has been billed as the underground drilling technology of the 1980's got a dramatic head start when Boliden engineers at Stekenjokk decided to go with all hydraulic drilling for primary ore production and mine development. This application represents a major first in meeting the needs of high productivity, better energy utilization, and an improved drilling environment. At Stekenjokk, engineers chose three Atlas Copco Boomer H132 two-boom electro-hydraulic drill rigs with the COP 1038 rock drills. An additional single-boom Boomer H131 was also selected with the COP 1038 HD for roof bolting functions.

Jan 12, 1977

By C. O. Brawner

Introduction The procedures used to design slopes in rock have only been developed over the past 10 years. Therefore, continued review and assessment of field experience by the publication of case studies is necessary to determine the accuracy of the theory and the application of the design techniques being used. Where failures have occurred, mine management should insist that the slides be 'back analyzed' to determine the shear strength parameters at failure. These values should be used for any pit design as they reflect site conditions more accurately than any other procedure. The previous papers have dealt with the basic concepts and factors that influence stability. To illustrate the application of these concepts in the study of practical stability problems, six ease studies have been selected for review. The examples include failure of tailings dams due to an earthquake, failure and redesign of a slope in overburden, review of failures of rock slopes, calculation of the amount of seepage into a pit and influence of the groundwater on stability, and the design of slopes for a proposed 2,500 ft. deep open pit mine. All but the first example are drawn from the authors personal experience. EXAMPLE 1 Failure of Tailings Dams Due to an Earthquake On March 28. 1965 a serious earthquake occurred in Chile with the epicenter located near the town of La Liqua, about 80 miles north of Santiago. The earthquake had a rating of 7 to 7.25 on the Richter scale. A record of the acceleration was taken at Santiago where a maximum horizontal acceleration of 0.18 g. was recorded. Many small mines are located in this region. Each of the mines provided impoundment storage for tailings with one to three dykes. As a result of the earthquake, most of the dams failed. The most serious failure involved two dams at El Cobre where more than 2,700,000 cu. yd. of tailings flowed into the valley, travelled over 7 miles in a few minutes, destroyed part of the town of El Cobre and killed more than 200 people. The Chilean government commissioned an investigation into the failures. A summary of the findings was published by Dobry and Alvare7 in 1967 (1). The location of the earthquake and the tailings dams which were investigated is shown

Jan 1, 1971

By D. W. Fuerstenau

Locked-cycle grinding experiments on mineral mixtures provide a means to study circuit performance in simulated continuous grinding systems. Such experiments with calcite/quartz mixtures revealed that approximately twenty-five 2-minute cycles are required before the composition of the circuit product and the recycle material attain steady state. The circulating load, after steadily increasing during the first 15 cycles, continued to fluctuate over a narrow range. Previous batch ball mill grinding of mineral mixtures has shown that breakage rate functions of minerals are time- independent but composition-dependent. In the closed-circuit grinding of ores with constituents having different grindabilities, the grinding rate parameters for the components also would therefore change during the transient period. With fluctuations in feed composition occurring randomly every half to one hour in processing plants, it is quite likely that the grinding circuit can be in unsteady state perpetually. The significance of these observations is discussed in this paper in the con- text of the models used in control schemes for the grinding circuits

Jan 1, 1984

By M. C. Fuerstenau, R. K. Price, R. D. Wellik, B. M. Wakawa

Median lethal concentrations of pure and commercially available ethyl xanthate, isopropyl xanthate, amyl xanthate, diethyl dithiophosphate, dibutyl dithiophosphate, and isopropyl ethylthionocarbamate for rainbow trout have been established utilizing static bioassays.

Jan 1, 1975

By Wendell E. Dunn

INTRODUCTION The early history of the chloride process has been recorded in a chapter of a Bureau of Mines bulletin (9 by one of the inventors of a chloride process, Stewart Croasdale, who is famous for the Pohle- Croasdale Process. The earliest use of chlorine in metallurgy was in 1557 by Bartholome Medina. But apparently even earlier there was knowledge that salt could be used in gold and silver extraction because a treatise, de la Pyrotechnica, published in 1540 in Venice, asserted that silver could be obtained from its ores by a wet salt process. In 1609 a priest, Alonzo Barba, invented a process using a copper vessel and boiling a solution of salt to extract silver chloride ores. The copper vessel was, of course, one of the reactants. This led to the Kronke process introduced in Chile in 1860 which substituted cuprous chloride for the kettle. A major step was taken in Europe in the late 1700's to chloridize roasted silver ores in combination with amalgamation using iron to reduce the silver chloride. By 1843 the Augustan process was introduced. Ores were roasted with salt and leached with a saturated salt solution. The silver chlorides passed into solution from which silver was precipitated by copper. In 1848 sodium or calcium thiosulfate solution of silver chloride was suggested by Dr. John Percy, and the idea was applied in 1856 by Von Patera in Bohemia.

Jan 1, 1983

By R. P. Killmeyer, B. S. Gottfried, J. T. Wizzard

The US Department of Energy's Coal Preparation Branch has developed a computer program to calculate the performance characteristics of coal washing devices. This program uses specific gravity analyses of the clean coal and refuse streams as input, and generates dependent and independent performance criteria for the washer. Partition curves are internally represented in a functional form by a Weibull function. Comparisons are made between performance criteria calculated by hand and the performance criteria calculated by the program for 120 different dense medium cyclone tests. Results show that the computer program gives results in close agreement with hand-calculated values while greatly reducing the amount of time involved in performing the analyses.

Jan 1, 1984

By C. N. Schuette

THE producers of this liquid metal call it quicksilver, while the consumer generally refers to it as mercury. It is one of he seven metals that were known to the ancients. These seven were gold, silver, iron, copper, quicksilver, lead, and tin. Other metals were sometimes accidentally alloyed with some of these, but it was not until 1490 that antimony, for example, was discovered and identified as a separate metal. It is not surprising that quicksilver should have been known in ancient or even in prehistoric times, as globules of the native metal often occur in the outcrops of the ore. Furthermore, the first man to build a fire on an outcropping of quicksilver ore would probably have found globules of quicksilver in the cold ashes of his fire after it burned out. The inability to pick up the globules with the fingers would excite interest and an attempt to gather it in shells or gourds to be exhibited and traded. The ore of quicksilver is the red sulfide, cinnabar, which has been mined and used as the pigment vermilion since before the beginning of written history. In recorded history, quicksilver is first mentioned in documents by Aristotle, 384-322 B.C. Theophrastus, in 315 B.C., credited the Athenian, Callias, with the invention of methods to beneficiate cinnabar in 415 B.C. In China also there are records antedating Christ which mention both vermilion paint and the fluid metal. From these early records, it seems certain that not only was cinnabar used as a pigment in those days but also that the metal was reduced from the ore and was used for amalgamation, for gilding, and for medicinal purposes. Quicksilver mining and metal-

Jan 1, 1953

By H. E. Crum, W. E. Hubbard

This review covers the northern 32 counties of the Texas Panhandle, an area 180 miles square. The westerly three-fourths of the district lies wholly within that great area known as the Llano Estacado or "staked plains." Six of the counties produce oil and gas and three produce gas alone. All of the production is associated with the Amarillo arch, a huge anticline superimposed upon a buried mountain range which is undoubtedly a continuation of the Wichitas of southwestern Oklahoma. Oil Production The production of the Texas Panhandle up to Jan. 1,1930, was slightly over 157 million barrels, 90 per cent. of which came from Hutchinson and Gray counties. About 33,000,000 bbl. was produced during 1930. Though this was about 9 per cent. above the 1929 production, it was over 8,000,000 bbl. less than was produced during the peak year, 1928. The present daily production is slightly over 40,000 bbl., which is the allowable production under state-wide proration. The assumed potential for the purpose of proration is 124,500 bbl. and the actual capacity of the wells probably would be in the neighborhood of 100,000 barrels. The total initial production of the oil wells completed in 1930 was 157,289 bbl. from 308 wells, or 511 bbl. per well, as compared to a 734-bbl. average from the 350 oil wells drilled during the preceding year. The completions in Gray County numbered 232, with an average initial of 614 barrels. Completions During 1930, 526 wells were completed in the Panhandle as compared to a total of 503 during 1929. Of the year's completions, 308 were oil wells, 169 produced gas and 49 were dry holes. Of the 3027 wells drilled in the Panhandle to date, 2780 have produced oil, gas or both, making the ratio of dry holes to producers about 1:11.3. Ignoring the 63 dry holes drilled in nonproductive counties, the ratio becomes 184:2780 or 1:15.1 which is slightly less favorable than that which obtained at the end of 1929.

Jan 1, 1931

By Don C. Blackmar

The production of non-ferrous secondary metals has become a large and important industry in the United States, and deals with practically cvery type of manufacturing concern. Its business is unique in that it generally buys frorn its customers as well as sells to them, whether they are individuals, cities, corporations, or the United States government. Its operations are of vital importance to the success and prosperity of nlany of the nation's most important manufacturers; yet there are few industries about which less is generally known by those outside it, whether concerning the rliagnitude of its operations or the details of its actual technique. The industry itself is to blame for this meager publicity, because its technical men have made few attempts to openly exchange ideas, in spite of the excellent examples set by the iron and steel or the copper and brass industries. Whether this is due to the ancient shroud of secrecy generally supposed to cover smelting operations, or because its technical men actually felt that the industry was too puny to be interesting, is hard to say. This paper will consider its subject in a general way, attenlpting to show something of the size and importance of the industry, as well as its fitness to do its work well. Attention will be called to the sound economic reasons for the handling of non-ferrous wastes by specialists, and to the often unseen losses of metals and labor which occur when manufacturc~rs rcclairn thrir own metallic wastes. Magnitude of the Modern Industry No particular thought is given to the kitchen accident whereby a ruined saucepan is sorrowfully tossed into the ash can, yet it is a fairly safe guess that within a month this saucepan, together with hundreds of its follows, will again be in service, perhaps in an autonlobile crankcase, or in an electric vacuum sweeper. It is by this conversion of the useless into the useful, whether from home or large manufacturer, that the secondary tonnage is built up.

By T. F. Witherbee

That the single charging-bell, properly proportioned, is a good all-around device for distributing material in a blast-furnace can scarcely be questioned; yet it is equally true that, in some cases, it has not given perfect satisfaction; as has been demonstrated by the substitution of double bells, at furnaces under the beat management—generally in cases where anthracite, either alone, or with a portion of coke, was used as fuel. The defect of the single bell seems to be that it does not permit, beyond very narrow limits, such changes in charging as may be required by the temporary conditioil of the furnace. Modern furnaces using Connellsville or other good coke and Lake Superior ores seem to be well served with a single bell. At least, up to a certain size, somewhere about 18 by 85 ft. to 19 by 90 feet, these furnaces make low-silicon pig-iron with about 1,800 lb. of fuel, or in some cases very much less. The following instances occur to me, in which other forms of charging-apparatus have been employed with advantage: 1. A charcoal-furnace, 61 ft. high, 11 ft. in diameter at bosh, and 8 ft. 2 in. at stock-line, with a rectangular crucible, 42 by

Jan 1, 1905

By H. M. Chance

Asst. Geologist, Pennsylvania Geological Survey THE following tables have been compiled from the annual reports of the Inspectors of Mines, to determine the percentages of fatal and non-fatal casualties from roof-falls and explosions of fire-damp. As we cannot assume that every accident has been recorded by the inspectors; as many casualties terminating fatally after the lapse of a considerable period, are inevitably recorded as "non-fatal;" and as clerical errors may have crept into the compilation,* the figures of these tables cannot be considered absolutely correct, but the summary is sufficiently reliable to show the features I wish to differentiate. Under the heading a Miscellaneous" are included all accidents not directly attributable to explosions of fire-damp, roof-falls or falls of coal. Prominent among the numerous causes included under this head are premature or delayed explosion of blasts, accidental explosion of powder or cartridges, accidents from mine cars, falls in shafts, machine accidents, sliding of loose coal in pitching breasts, sltffouration by choke-damp, etc., comprising in all 48 per cent of the total number of casualties. * Compiled by Mr. Maxwell Chapman

Jan 1, 1882