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In 1846 a bill was pending in Congress to reduce, or eliminate, the tariff on coal; the debate caused the same writer to visit the mines on the north side of the James River and to write a letter about them to the same paper.' Omitting the political arguments, his account follows: "July 13, 1846. "Early in the morning we rose, washed, combed, and ate a first-rate breakfast, and then went to the Tuckahoe, mined by Messrs. Sneed and Dietrock. Coal was first discovered here sixty years ago, and mined by Colonel Thomas Randolph, the proprietor of the land. They were worked by him for his smith-shops. Since which time they have been worked periodically, up to the war of 1812, when they were abandoned; and recommenced in 1837 under the management of Dr. W. T.- Scott. Subsequently a Company was formed called Tuckahoe Coal Mining Company, which purchased the whole track at a cost of $30,000. They commenced the sinking of a shaft and went as far as 412 feet, and then pitched the fat all into the fire by hauling off altogether in despair. In 1843 Major Sneed went to work at it, and succeeded. I may here remark that Major Sneed has been the pioneer in this business on the North side of the River, and has sunk more shafts than any other man who has pursued this vocation in Eastern Virginia. The difficulties and expense in sinking these shafts are sometimes immense. The coal on the outcrop or surface is not always a guide to where it may be found imbedded many hundred feet under earth and rock. "The Tuckahoe Pits are on the Eastern end of the coal field, within twelve hundred yards of the Canal, and about twelve miles from Richmond. They employ fifty hands and raise some three hundred thousand bushels of coal per year. It is highly bituminous and excellent for the manufacture of iron. The Tredegar and Belle Isle Rolling Mills are supplied with it. It must be good and of the right kind', or they would not use it. These pits are the only. ones on this side troubled-with gas-of course ventillation is necessary. There is not as much water in this Pit as I have found generally in many others, although they have extended their operations to a considerable distance under ground. I have observed in examining the coal mines, that, where they are sunk over four or five hundred feet, they are annoyed by gas, and where there is a less depth they are troubled with water. It is evident, therefore, that water, in the region of these coal fields, does not run through the earth to any extent, even five hundred feet deep, and the farther you go below that the greater the increase of gas. "We next visited William Cottrell's Pits, situated one mile and a half north of this. He employs some thirty hands, and raises from 4 to 500 bushels per day. "T. & R. Crouch's Pits are one hundred yards north of Cottrell's. This firm employ from 80 to 90 hands, and raise from 8 to 900 bushels per day. They are now

Jan 1, 1942

By Ernest Lilley

WHILE American scientific literature contains much information upon geologic conditions controlling the production of oil in Rumania, copper in Chile, and other fuel and metallic resources in many foreign countries, it is singularly lacking in data about the nonmetallics outside of the United States. Thus, though the United States is the outstanding market for European high-quality refined kaolin, and for the chinaware, porcelain, and other products of the European ceramics industries, Amer-ican literature contains only the briefest references to the deposits from which the raw kaolin utilized is obtained. To the writer, to whom has come in the past year .the opportunity of visiting a number of these deposits personally, they have proved of extreme interest both com-mercially and geologically. It is the latter phase that is discussed in this paper. The older and now largely crystalline rock areas of France, Germany, ;end other parts of western Europe contain numerous pegmatite dikes of which the upper portions have been subjected to surface weathering and kaolinization in much the same way as those of the eastern portion of the United States. Like the latter, the European pegmatite kaolins have long been known for their freedom from iron and other impurities offensive to the china and porcelain manufacturer. Unfortunately, they are also, like the American deposits, individually of small size and noted for their high costs of production. Deposits of sedimentary clay similar in many respects to the high-quality sedimentary kaolins of Georgia and South Carolina are known and worked, notably in southern Germany and in the Newton Abbott district of Devon and Dorset. in England. In general, their relationship to the parent rock from which they were derived is more evident than in the United States and the individual deposits are of smaller areal extent and less regular in outline.

Jan 1, 1932

By E. M. Murphy

Eight years ago the Hecla mine, a lead-silver producer, situated at Burke, Idaho, was producing ore from but two levels, the 300- and the 600-ft. All hoisting was done with a 12- by 16-in. slide-valve, double-reel, hoist. The hoist was being worked to its capacity and was unsuitable for hoisting from greater depths. As the work of opening a new level was about to be started, it became necessary to remodel the then-existing equipment or install a new hoist. The recent advent of electricity from Spokane had made available a cheaper power than steam. By a series of tests conducted throughout the Cæaur d'A1ene district, it was found that it cost $109 per year to generate a horse-power with steam. Electric power was to be had for $50 a horse-power per year. It was decided to substitute for the engines a motor-drive, of sufficient capacity to operate from the 900-ft. level, and ultimately install an entirely new hoist. After disconnecting the engines, installing a new shaft, and making a few minor changes, a 300-h-p., 2,300-volt, 514-rev. per min., variable-speed motor of the induction type was geared to the reel-shaft. The reels were supplied with 3/8- by 4-in. flat rope, and the duty of the hoist was about as follows: Cage, 1,700; ore, 2,600; car, 1,400; rope, 2,250; total, 7,950 pounds. The Bristol ammeter chart, Fig. 1, shows the combined current-consumption of the hoist- and mine-motors. The large intermittent load is clearly shown; this produced harmful fluctuations in the voltage of the long, lightly-loaded, 60,000-volt transmission-line from Spokane to the Cæmur d'A1enes. The power company received no compensation for the increased cost of producing power for this intermittent or fluctuating load. In order to protect its system from similar excessive

Jan 1, 1913

By Jay A. Carpenter

IN six years the construction of Hoover Dam and the power plants probably will have reached the operating stage and this vast new source of power will then be continuously available for industry. The height of the darn will be 580 ft. and the average annual flow of the Colorado River is calculated at approximately 24,000 cu.ft. per sec. If this full head and average flow can be maintained the year round, about one million horsepower will be generated. The U. S. Reclamation engineers, taking into consideration the probable range in flow and head, have set the figure for power contracts at 660,000 firm horsepower, which can be assured at all times of the year. During the months of heavy run-off of water from the Colorado River Basin the power plants should be able to generate the full 1,000,000 hp. capacity of the power plants, so there will be 340,000 excess or secondary horsepower. The cost of firm power at the switchboard will be close to 2.15 mills per kw.-hr., equal to $14.05 per hp.-yr., and the cost of the secondary or off-peak power will be close to 0.8 mills per kw.-hr., or $5.22 per hp.-yr. In no place in the country can such cheap power be obtained today. The electrochemical industry is in a state of flux because the power costs from its old sources have increased so much (to $30 per hp.-yr. at Niagara) that the industries have had to seek new sources, so they have gone to Canada and Norway and built new plants.

Jan 1, 1932

By Geoffrey Gilbert

The material that forms the basis of this paper was collected in the spring of 1922, during a ten-day visit to Ducktown by the writer in the company of Prof. L. C. Graton. The time available for the work was far too short to allow anything like a thorough study of the deposits, and structural and stratigraphic questions, though they have an important bearing on the origin of the primary ores, were necessarily left untouched. Attention was focussed on the zone of oxidation and enrichment; and by devoting most of our time to the upper levels, open pits, and old workings, and examining the deeper levels only thoroughly enough to obtain a fair idea of the nature of the primary sulfide ore, we were able to make a reasonably complete survey of the various orebodies. With this field work for a background, the writer later made a study, in the Harvard laboratories, of the specimens obtained during the visit. As some of the facts brought to light by this study appear to be new, it seems worth while to set forth the outstanding features and a proposed explanation of them. Much of the Ducktown material that is obviously of greatest significance, as regards oxidation and enrichment, is soft and crumbly. Notwithstanding the desirability of gaining from such material all possible information as to its mineral composition and textural relationships, but little has heretofore been learned regarding it; but, by suitable preparation of this material in connection with the present study, it has been possible to examine it under the microscope without any disturbance of its texture and about as satisfactorily as if it were hard, fresh ore. The information thus gained has contributed measurably to the results set forth in this paper.

Jan 1, 1924

By D. B. Williams

For the first time in the history of the Venezuelan petroleum industry production exceeded 200 million barrels. The total production for all fields amounted to 205,430,869 bbl., which is more than 9 per cent of the world's 1939 total. This is an increase of over 15 million barrels or 8.0 per cent above the 1938 figure, which, compared with the slightly less than 2 per cent increase of the 1938 figure over 1937, shows the marked activity in Venezuela during the past year. The Maracaibo Lake fields are still the predominating factor in Venezuelan production, showing an increase of approximately 9½ million barrels over last year's figure and accounting for 71.8 per cent of Venezuela's total. Lagunillas continues to hold precedence as a single field, having yielded 47.1 per cent of the accumulative total and 39.4 per cent of 1939's total. This field showed an increase of slightly more than 3½ million barrels over 1938. Tia Juana, the second largest field, attained a record production, increasing its percentage of the Venezuelan total from 23.4 in 1938 to 23.7 in 1939. The La Rosa field, which includes Punta Benitez and Ambrosio, declined from 13.7 to 12.0 per cent; Bachaquero, the southernmost Lake field, which came into regular production at the end of 1938, contributed over 31/3 million barrels. Quiriquire, in eastern Venezuela, ousted La Rosa as the third largest producing field, and, although production increased by 11/3 milliorl barrels, percentage of the total declined from 13.2 to 12.9. Mene Grande, the oldest field, declined from 6.6 per cent in 1938 to 5.9 in 1939. Tem-blador produced for a whole year for the first time and yielded 3,647,867 bbl. The Colon district, in the Maracaibo Lake area, comprising the Tarra-Los Manueles fields, showed slight increases, as also did Cumarebo and Pedernales. Construction of the 16-in. pipe line from Oficina to Puerto La Cruz (Guanta), the longest line of this size in the world, was completed toward the end of the year and this new field in eastern Venezuela started shipping oil in December. This field is operated by the Mene Grande Oil Co. and was credited with a production of 2,347,625 bbl. in 1939. Jusepin field, some 25 miles southwest of Quiriquire in eastern Venezuela,

Jan 1, 1940

By D. B. Williams

For the first time in the history of the Venezuelan petroleum industry production exceeded 200 million barrels. The total production for all fields amounted to 205,430,869 bbl., which is more than 9 per cent of the world's 1939 total. This is an increase of over 15 million barrels or 8.0 per cent above the 1938 figure, which, compared with the slightly less than 2 per cent increase of the 1938 figure over 1937, shows the marked activity in Venezuela during the past year. The Maracaibo Lake fields are still the predominating factor in Venezuelan production, showing an increase of approximately 9½ million barrels over last year's figure and accounting for 71.8 per cent of Venezuela's total. Lagunillas continues to hold precedence as a single field, having yielded 47.1 per cent of the accumulative total and 39.4 per cent of 1939's total. This field showed an increase of slightly more than 3½ million barrels over 1938. Tia Juana, the second largest field, attained a record production, increasing its percentage of the Venezuelan total from 23.4 in 1938 to 23.7 in 1939. The La Rosa field, which includes Punta Benitez and Ambrosio, declined from 13.7 to 12.0 per cent; Bachaquero, the southernmost Lake field, which came into regular production at the end of 1938, contributed over 31/3 million barrels. Quiriquire, in eastern Venezuela, ousted La Rosa as the third largest producing field, and, although production increased by 11/3 milliorl barrels, percentage of the total declined from 13.2 to 12.9. Mene Grande, the oldest field, declined from 6.6 per cent in 1938 to 5.9 in 1939. Tem-blador produced for a whole year for the first time and yielded 3,647,867 bbl. The Colon district, in the Maracaibo Lake area, comprising the Tarra-Los Manueles fields, showed slight increases, as also did Cumarebo and Pedernales. Construction of the 16-in. pipe line from Oficina to Puerto La Cruz (Guanta), the longest line of this size in the world, was completed toward the end of the year and this new field in eastern Venezuela started shipping oil in December. This field is operated by the Mene Grande Oil Co. and was credited with a production of 2,347,625 bbl. in 1939. Jusepin field, some 25 miles southwest of Quiriquire in eastern Venezuela,

Jan 1, 1940

By M. E. Hassan, J. C. Calhoun, R. F. Nielson

An apparatus was constructed for the measurement of inter-facial tensions over a range of temperatures and pressures. This apparatus utilized the pendent drop method, and resembles in construction similar apparatus recently described in the literature and in use in some petroleum research laboratories. The interfacial tensions of benzene, propane, n-pentane, n-hexane. n-octane. and iso-octane against water were measured at temperatures ranging from 26" to 82" C and at pressures ranging from 1 to 204 atm. Values of interfacial tensions for the henzene-water system and their variations with temperature and pressure are generally in good agreement with value? of previous investigations. The data in all cases showed a slight decrease of interfacial tension with pressure at constant temperature in the range studied. The effect of pressure became less as the pressure was increased, with an indication of a reversal of the effect at higher pressures. There was a decrease of interfacial tension with temperature at constant pressure in all cases, as would normally be expected. This rate of decrease became greater the higher the temperature. A general equation is presented for the interfacial tensions as a function of presPurp and temperature over the range studied, and the constants calculated for each system. A definite trend was found in the effect of molecular weight on the interfacial tension at a given temperature and pressure, for the homologous series from propane to n-octane. Data for n-decane from the literature fitted well into this trend. INTRODUCTION It has been recognized for many years that surface forces play an active part in the production history of an oil reservoir as well as in determining the amount of unrecoverable oil. The magnitudes of these forces are governed by the values of the interfacial tensions. These vary greatly with composition, pressure, and temperature. The effect of composition is greater than that of pressure and temperature over the ranges normally encountered. In fact, because of the variety of compounds present in a crude, no attempt has yet been made to correlate crude composition with its surface tension or with its interfacial tension against water. The amount of dissolved methane greatly affects the surface properties of an oil, and there are "surface-active" compounds in crudes which have a much greater effect on boundary tensions than do equal amounts of hydrocarbons. The purpose of the present work was partly to contribute data that would eventually be used in correlations applicable

Jan 1, 1953

By Theron Wasson

Michigan's production of 17,301,000 bbl. in 1945, which is in line with previous years, has been maintained by extensions to old fields like Deep River, Adams, Fork, and others. There were a number of new discoveries but, as in the past, these are not given very much importance because enough drilling has not been done to develop their potentialities; however, judging by the past, some of them will develop enough production so that 1946 -will probably be in line with other years. Activities in Michigan were confined to the Basin area of the lower Peninsula, which has been under development since 1925.

Jan 1, 1946

By J. L. Lamon, W. Crafts

P. Coheur and L. Habraken—We read this paper with great interest and are glad to congratulate the authors for their valuable work, supplying an important contribution to the mechanism of tempering on the carbides in vanadium steels. We are in a good position to appreciate this work since we have been studying, for more than a year, Cr-Mo steels of a composition similar, but less highly alloyed (namely 0.1 pct C, 3 pct Cr, 1 pct Mo). Our results are quite in concordance with the authors', however, we wish to point out that it is very interesting to use equally the electron microscope in order to observe the variations of microstructure in steels. We have studied simultaneouslv the evolution of the carbides in situ with the electron microscope, and, after extraction, again with the electron microscope, and then with X-rays. The first results which we have obtained have been communicated at the Congress of Delft (July 1949) and at the "Journbes de la Metallurgie" in Paris (October 1949). These may be summarized as follows: After tempering with varying either the tempering temperatures or the tempering times, the carbides show two evolutions. The first one is connected to the carbides existing in the steels, principally in the boundaries of the grains. For some groups of steels these carbides may coalesce and for other groups they may

Jan 1, 1951

By B. DE MARE

THE No. 6 open-hearth furnace at the plant of the Worth Steel Co., Claymont, Del., is the first to be rebuilt according to the Kuehn system. This as well as the other five furnaces at Claymont, has a nominal capacity of 75 tons, but the actual charge is about 242,000 lb. No hot metal being available, the pig-iron is charged cold. Oil of low grade with an asphalt base is used as fuel. These two items have to be kept in mind when discussing the actual fuel consumption. Careful records have been kept covering a five weeks run and the following is a brief summary of them The time required to heat the furnace preparatory to charging from the time a wood fire was started until charging commenced was 36 hours. This, I understand, is much less than with furnaces of standard design. The draft of the furnace, as shown by a gage in the stack-flue, is 1.25 in. The maximum draft with new checkers on former runs was 1.50 in., this draft gradu¬ally decreasing as the checkers closed up. Both of the first helpers claim the present draft is all they need for the proper working of the furnace, and, as with the Kuehn regenerators the draft remains practically the same from beginning to end of a run, this is satisfactory.

Jan 1, 1929

By Paul F. Kerr

QUARTZ of a certain kind, is one of our strategic minerals, and Brazil is probably the one important available source. Crystals of quartz of suitable size and perfection for piezoelectrical application are rare; their most outstanding use is in radio work. Clear quartz, or "crystal," free from twinning, cracks, foreign particles of other disturbing lines of growth, and gaseous or liquid inclusions, is cut into plates which provide excellent control of frequency in broadcasting. The squares or rectangles are less than a millimeter in thickness and ordinarily on the order of 1 in. along each side. They are cut at definite angles with respect to the axes of the crystal, and ground with opposite surfaces parallel. Each small slab must be a section of one crystal, uniform throughout in atomic alignment. The thickness of the chip controls the frequency of a broadcast and it is most important to have the plates oriented and ground with utmost precision. Opposite surfaces are parallel to within 0.001 mm. and expansion or contraction due to the temperature is limited to one part in a million.

Jan 1, 1942

W. L. Saunders, New York, N. Y.:—Mr. Parker's paper, though entitled Conservation of Coal, might also be called the Conservation of Life in the Coal-Mines of the United States. No subject is of greater importance to mining-men at the present time than information from experts as to how to save coal and how to save human lives in mines. That the casualties in the coal-mines should exceed 3,000 in the year 1907 is simply appalling, and that 1,000 men should have been killed in a single year through explosions alone, and that so good an authority as Mr. Parker should say that " a prolific cause " is an "improperly-prepared blast" or "the failure on the part of the miner to undercut his coal," points to the importance of activity not only among mining engineers but also, through experts, by the legislatures of the respective States. There is but little doubt that nearly all the serious coal-mine

Jan 1, 1910

By R. A. Deju, R. B. Bhappu

The basic structural unit of all silicate minerals is a tetrahedron with a silicon atom at the center and four oxygen atoms at the corners. The oxygen-silicon distance is about 1.6 & and the oxygen-oxygen distance about 2.6 &. The different types of oxygen-silicon frameworks in the various silicates are based entirely on the combinations of the tetra-hedral oxygen-silicon groups through sharing of oxygen atoms. In recent years, infrared spectroscopy has permitted estimation of the ratio of the ionic character of the oxygen-silicon bond to be a few times that of the oxygen-carbon bond and the ratio of electro-negativity of the two bonds has also substantiated this finding. On this basis, it is generally accepted that the oxygen-silicon bond is the strongest one occurring in silicate minerals. As the oxygen-silicon ratio increases from quartz to the olivines, a greater percentage of the oxygen bonding power is available for bonding to cations other than silicon. Hence, with an increasing oxygen-silicon ratio, there is increasing oxygen-to-metal bonding. Upon the fracturing of a silicate mineral crystal, the oxygen-metal bond, which is almost entirely ionic in character, should break more easily than the stronger oxygen-silicon bond, resulting in a greater number of unsatisfied negative forces on the surface. If, then the mineral is immersed in a liquid containing hydrogen ions, these negative forces should tend to be neutralized by hydrogen ions from solution, resulting in a change of the pH of the solution. An increase in the degree of adsorption of hydrogen ions is to be expected as the oxygen-silicon ratio in the crystal structure increases. This study attempted to correlate the oxygen-silicon ratio for various representative silicate minerals to the adsorption of hydrogen ions. Experiments to determine the effect of surface area on this adsorption and to investigate the effect of surface iron were also conducted. It is believed that such studies of the surface properties of silicate minerals will supply pertinent information about their behavior in froth flotation systems. EXPERIMENTAL PROCEDURE Ion Exchange: Carefully selected, hand-picked samples of the minerals investigated were dry-crushed in a ceramic ball mill and sieved to obtain a minus 100 plus 200-mesh sample. The sized samples were then run through the electro-magnetic separator to remove any iron-bearing particles. A 10-g sample of each mineral was placed in 100 ml of freshly deionized water previously adjusted to a pH of 3.50 with HCl. The beaker containing the sample and the water was placed under a bell jar from which the air was displaced at once by nitrogen gas from a tank. All experiments were carried out in a nitrogen atmosphere. The sample and solution were stirred gently but continuously during the entire experiment, the stirring speed being kept about the same for all runs. Changes in pH were followed with a Beckman Zeromatic pH meter and recorded on a

Jan 1, 1967

By Joseph C. Mead, James R. Cudworth

THE Birmingham district of Alabama has utilized the slag from its blast furnaces consistently since the earliest development of the slag industry. Today there are producers of slag cement who started business in 1900, and who have, under a progressive policy, expanded the number of their products to meet present demands. There are producers of slag aggregates and other crushed slag products who have been successful for periods of over thirty years. There are at the present two companies, Cheney Lime and Cement Co. and the Southern Cement Co., manufacturing puzzolan cement; two companies, Birmingham Slag Co. and Woodstock Slag Co., making slag aggregates and by-products; one company, Tennessee Coal, Iron and Railway Co., a subsidiary of the U. S. Steel Corporation, producing ground open-hearth basic slag for soil conditioning. Two companies, the Sloss Sheffield Steel and Iron Co. and the Woodstock Slag Co., make slag concrete in ready-mix plants and one company, the Superock Company, manufactures fine and coarse slag aggregates under a new granulation process. No Portland cement is made with slag as an ingredient, because dolomite is used so extensively as a blast-furnace flux that the magnesium content of the slag is excessive. Sources Of Slag In the Birmingham district there are 22 blast furnaces, of which the majority are in blast. The present production is 165,000 tons of pig iron monthly; the production in 1935 was 1,297,960 gross tons1. There are also two blast furnaces at Gadsden and one ferroalloy electric furnace at Anniston. From these two sources is obtained slag to approximately 1.1 tons per ton of pig iron.

Jan 1, 1937

By E. T. Turkdogan

The activity of sulfur was determined as a function of composition of ferrous sulfide by equilibrating with hydrogen sulfide-hydrogen gas mixtures at 670° , 800°, and 900". The present results supplement the available data over the composition range from 36.6 to 39.5 pct S. The X-ray lattice spacing measurements made are in accord with the available data and indicate that the limiting composition FeSl.008 may be taken for the iron-iron sulfide equilibrium. The growth rate of ferrous sulfide on iron was measured by reacting iron strips or blocks in hydrogen sulfide-hydrogen gas mixtures. Owing to the slow approach to equilibrium between the gas phase and the surface of the sulfide layer, The sulfidation experiments were carried out for several days. It is shown that the growth rate ullimately proceeds in accordance wilh the parabolic rate law. From the parabolic rate constants and the thermodynamic data on iron sulfide the self-difiusivity and chemical diffusivity of iron in ferrous bisulfide are evalualed. The self-diffusivity of iron thus derived zs found to increase with increasing sulfur content. THE ferrous sulfide known as "pyrrhotite" is a non-stoichiometric phase having a wide composition range from about 50 to about 58 or 60 at. pct, depending on the sulfur activity. RosenQvistl studied the thermodynamics of this phase over wide ranges of temperature and composition. Hauffe and Rahmel' and Meussner and ~irchenall~ studied the parabolic rate of sulfidation of iron in sulfur vapor. By using markers, these investigators showed that the iron cations were the predominant diffusing species in iron sulfide. This is confirmed decisively by the self-diffusivity measurements of condit4 who showed that the self-diffusivity of sulfur in ferrous sulfide is several orders of magnitude lower than the self-diffusivity of iron. Although much has been learned from these studies about the Fe-S system, further research on this subject was considered desirable for better understanding of the physical chemistry of iron sulfide. This work was confined to the study of the kinetics of sulfidation of iron in hydrogen sulfide-hydrogen gas mixtures. The results of this study are given in two consecutive parts. Part I, the present paper, is on the parabolic rate of sulfidation of iron and the diffusivity of iron in ferrous sulfide. The second paper, Part 11, is on the kinetics of the surface reaction between hydrogen sulfide and ferrous sulfide. EXPERIMENTAL Three types of experiments were carried out: i) equilibration of ferrous sulfide with gas of known E. T. TURKDOGAN, member AIME, is Manager,Chemical Metallurgy Division, Edgar C. Bain Laboratory for Fundamental Research, U. S. Steel Corp., Research Center, Monroeville, Pa. Manuscript submitted March 6. 1968. ISD sulfur potential; ii) X-ray studies of ferrous sulfide; and iii) measurements of the parabolic rate of sulfidation of iron. Equilibrium Studies. About 1 g of iron powder or foil. contained in a small recrystallized alumina crucible ind suspended from a calibrated silica spring, was reacted with a hydrogen sulfide-hydrogen mixture of known ratio until no further change in weight was observed. %hen the gas composition was changed and the new state of equilibrium was established after several hours of reaction time. The composition of the sulfide was obtained from the initial weight of the sample and the weight after equilibration. X-Ray Studies. The lattice parameters of some of the equilibrated samples were determined using the General Electric XRD-5 diffractometer with a cobalt tube (no filter) set at 40 kv apd 10 ma; the CoK, radiation was taken as 1.79020A. Observed 220 and 311 diffraction peaks of silicon served as an internal comparison standard to correct for possible misalignment of the goniometer. The lattice parameters of the sulfide phase were calculated from the corrected Bragg angles of the 110 and 102 peaks. Rate Studies. In the initial experiments attempts were made to measure the parabolic rate of sulfidation by measuring the gain in weight of a thin iron strip, -0.05 cm thick, suspended from a silica spring in the reacting atmosphere. The preliminary experiments showed that this technique was not reliable for the measurement of the parabolic growth rate of the iron sulfide layer. In the subsequent experiments the data on growth rate were obtained by measuring, on a microscope stage, change in the thickness of the sample after reaction for a specified time in a hydrogen sulfide-hydrogen mixture of known sulfur activity. For each reaction time a new sample was used. Precision-machined iron blocks, 0.5 by 2 by 5 cu cm, were de-greased and annealed in hydrogen for several hours prior to the sulfidation rate measurements. The experiments were carried out at 670°, 800°, and 900°C in gas mixtures having the ratios, and 1.0 for periods of times from a few hours up to 8 days. Apparatus and Materials. A vertical globar tube furnace with a 3-in.-long uniform temperature zone was used. The glass tube fittings were fused on the zircon reaction tube, 1.5 in. diam. The temperature was measured with a Pt-10 pct Rh/Pt thermocouple placed in the hot zone of the furnace inside the reaction tube (an alumina thermocouple sheath was used). A separate thermocouple was used for the temperature controller which maintained the furnace temperature constant within about 2°C. Anhydrous liquid hydrogen sulfide and oxygen-free dry hydrogen from gas tanks were used in preparing the gas mixtures by the constant head capillary flow-meters. In all cases volume flow rate was 1000 cu cm per min at stp, corresponding to a linear velocity of about 6 cm per sec at 800°C; under these conditions

Jan 1, 1969

By AIME AIME

PETROLEUM technology was the sole subject of discussion at the meeting of the Petroleum Division at the Baker Hotel, Dallas, Texas, Oct. 6-7, except for the brief talks by President Becket and Secretary Parsons at the dinner on Friday evening. Even on this occasion, following the scheduled official features, it was in order to talk "shop." W. E. Wrather and E. A. Stephenson, respectively Chairman and Secretary of the Division, had planned for a meeting of this nature and by preference, apparently, the 122 who registered fell in with the scheme wholeheartedly. Not because the competent local committee had not provided for it, but by choice, the members just did not sign up for entertainment or field trips, but did attend largely the three technical sessions and engage in earnest discussion of the approximately dozen excellent papers. In this connection, and without question, the high lights of the meeting were the papers by Morris Muskat and R. D. Wyckoff, and Prof. W. K. Lewis. The former, entitled, "A Theoretical Analysis of Waterflooding Networks," had been entirely demathematized by the authors for presentation at this and the Los Angeles meetings; the author of the latter, which was on the "Physical-chemical Relationships of Hydrocarbon Gas-liquid Mixtures at High Pres¬sures," had airplaned to Dallas in the company of Dr. H. D. Wilde from Chicago in order to present his paper at the final session on Saturday morning.

Jan 1, 1933

By S.S. Clarke

The sheet-ground deposits of the Tri-State district, because they are fairly uniform in thickness (7 to II ft.)—rather flat, with an easy dip to the west—and cover a large acreage, offered a problem of improved transportation. Heading advance in this kind of mine is very rapid and track haulage requires a larger crew of trackmen than do other mines, and a heavy investment in track. The use of some type of rubber-tired truck equipment for underground haulage was under consideration for some time by the Eagle-Picher Mining and Smelting Co. The nature of some ore bodies made them not adaptable to truck haulage and some mines that did offer possibilities were equipped with other types of haulage, and the expected savings by the use of trucks did not offset the loss of investment that would be incurred in discarding other equipment. The decision was made to sink a new shaft, designed for skip hoisting, on the Blue Goose ore body, and then develop truck equipment. Developing Tractors and Trailers A study was made of internal-combustion engines for power units in the tractors, but the extreme difficulty of controlling air circulation, and the heavy cost of drilling large churn drill holes for blower installations, led to the adoption of a tractor with a storage battery. The storage-battery tractor that was on the market for mine haulage was impossible to obtain because all were needed for defense work. Several standard electric-truck chassis were purchased and rebuilt in the Eagle-Picher shops. The steering wheel was shortened and set vertical, permitting the driver's seat to be moved forward, and the frame was shortened enough to take the battery box and the fifth wheel support that carried the gooseneck of the dump trailer. The fifth wheel, or turntable, is of the ball and socket type. Tig. I shows the ball fastened to the gooseneck. The socket is split to permit introduction of the ball and is held by through-bolts, and the socket is welded to a ½-in. plate, which in turn is attached to the tractor frame. Smaller wheels and tires were put on to reduce over-all height. If it had been necessary, the spring: could have been reversed, or taken off entirely, to gain additional clearance. The tractors are equipped with 48-cell, 23-plate, 400-A.H. batteries. With the initial tonnage and mileage, the batteries were about 50 per cent down at the end of a shift. Tractors have truck tires 7.50 by 20, 8-ply, front and rear, the rear being dud. After four months of use, the .tires are beginning to show signs of failure.* In

Jan 1, 1943

By S. S. Clarke

The sheet-ground deposits of the Tri-State district, because they are fairly uniform in thickness (7 to II ft.)—rather flat, with an easy dip to the west—and cover a large acreage, offered a problem of improved transportation. Heading advance in this kind of mine is very rapid and track haulage requires a larger crew of trackmen than do other mines, and a heavy investment in track. The use of some type of rubber-tired truck equipment for underground haulage was under consideration for some time by the Eagle-Picher Mining and Smelting Co. The nature of some ore bodies made them not adaptable to truck haulage and some mines that did offer possibilities were equipped with other types of haulage, and the expected savings by the use of trucks did not offset the loss of investment that would be incurred in discarding other equipment. The decision was made to sink a new shaft, designed for skip hoisting, on the Blue Goose ore body, and then develop truck equipment. Developing Tractors and Trailers A study was made of internal-combustion engines for power units in the tractors, but the extreme difficulty of controlling air circulation, and the heavy cost of drilling large churn drill holes for blower installations, led to the adoption of a tractor with a storage battery. The storage-battery tractor that was on the market for mine haulage was impossible to obtain because all were needed for defense work. Several standard electric-truck chassis were purchased and rebuilt in the Eagle-Picher shops. The steering wheel was shortened and set vertical, permitting the driver's seat to be moved forward, and the frame was shortened enough to take the battery box and the fifth wheel support that carried the gooseneck of the dump trailer. The fifth wheel, or turntable, is of the ball and socket type. Tig. I shows the ball fastened to the gooseneck. The socket is split to permit introduction of the ball and is held by through-bolts, and the socket is welded to a ½-in. plate, which in turn is attached to the tractor frame. Smaller wheels and tires were put on to reduce over-all height. If it had been necessary, the spring: could have been reversed, or taken off entirely, to gain additional clearance. The tractors are equipped with 48-cell, 23-plate, 400-A.H. batteries. With the initial tonnage and mileage, the batteries were about 50 per cent down at the end of a shift. Tractors have truck tires 7.50 by 20, 8-ply, front and rear, the rear being dud. After four months of use, the .tires are beginning to show signs of failure.* In

Jan 1, 1943

By Frederick Laist, H. J. Maguire

The ore from the Butte mines of the Anaconda company is quite siliceous; that is, it contains considerably less iron than is needed for the fluxing of the silica. The direct smelting of this ore, therefore, requires the addition of considerable fluxing material. The only flux available in sufficient quantity at Anaconda is limestone containing no metallic minerals. This necessarily makes the direct smelting of the ore so expensive that it is more profitable to subject the ore to a preliminary treatment by concentration. However, as the losses in the concentrator were very high, compared with the losses in the blast furnaccs, it was found, by calculation, more profitable to send ores containing more than a given percentage of copper to the blast furnaces, in spite of the higher costs of treatment. The dividing point was dependent on various factors, the chief of which was the prevailing market price of copper. It was customary, therefore, to segregate the ore as mined into two classes. Ore in the first class generally contained 5 per cent. or over of copper; this was sent directly to the blast-furnace department. Second-class ore contained less than 5 per cent. of copper, and averaged around 3 per cent.; it went to the concentrating department. With the introduction of the flotation process, it mas found possible to maintain an average recovery, as concentrates, of 96 per cent. At the same time, the cost of reverberatory smelting was very materially decreased by the use of pulverized coal. These two changes in practice made the blast furnaces unable to compete with the reverberatory furnaces on a cost basis. The distinction between first- and second-class ore was therefore abandoned, and the ore was treated by concentration. Obviously, on ores as high in iron as the Butte ores, the concentrator produces a product that is self-fluxing; in fact, it is possible to produce a concentrate containing more iron than is necessary to flux the silica. Under these conditions, the amount of basic fluxing materials required for the smelting operations became very srnall and the converter slag lost its former value as a blast-furnace flux. For this reason, a less expensive method of recovering the copper, silver, and gold contained in it than smelting in blast furnaces had to be found. It was not feasible

Jan 1, 1921