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By DR. DOUGLAS

Discussion of the Paper of Dr. Douglas, presented at the Toronto Meeting of the Institute, July, 1907 (Trans., xxxviii., 455 to 471). EDGAR HALL, Silverspur, Queensland, Australia (communication to the Secretary*) :-Dr. Douglas has written on this subject before, and his influence has had a powerful effect on the side of freedom among the younger generation of engineers. Moreover, it is not the first time that he has attributed the decline of the copper-smelting industry in Swansea to the secrecy maintained by the firms there engaged in smelting-operations. In this latter statement I think his conclusions are open to criticism. Whether the firms referred to have suffered by their secrecy is their own business-I. bold no brief for them ; but that the decline of the copper-industry at Swansea was inevitable seems to me to be proved conclusively by Dr. Douglas's own writings. In his paper on The Copper Situation,1 Dr. Douglas says "In comparing iron and copper mining, . . . it must be remembered that 2 tons of average iron ore from the most prolific source now available will make 1 ton of metal; whereas from 33 to 75 tons (say an average of 50 tons) of copper ore must be mined to produce 1 ton of copper." And further: "Last year's production of iron was made from approximately 50,000,000 tons of ore. Our copper mines, to yield a production of 900,000,000 pounds, must have handled approximately 22,000,000 tons of ore, or nearly half the quantity raised from our iron mines." Is not this the key to the whole situation ? In transporting the 50,000,000 tons of iron-ore, 25,000,000 tons of the metal iron were carried so much nearer to the market, but the transportation of 22,000,000 tons of copper-ore would have carried only 450,000 tons of the metal copper nearer to its ultimate destination. The small percentage of copper available in its ores makes

Sep 1, 1908

By D. S. Flett, A. W. Fletcher

Equilibrium studies on the extraction of nickel and cobalt with kerosine solutions of naphthenic acid have shown that an exchange extraction reaction occurs at pH 5.5. The nickel/cobalt separation factor is constant at 1.8 for constant total metal molarity and varying nickel/cobalt ratios. The separation factor decreases with increasing total metal molarity in the organic phase beyond 0.2 M and also decreases with increasing temperature. From the equilibrium data, it has been possible to derive a mathematical model for the separation of nickel from cobalt by exchange extraction in multistage systems. Experimental data from a continuously operated multistage mixer/settler apparatus has shown a reasonable correspondence with computer-calculated data. The effective separation of nickel and cobalt in sulfate solution remains a problem in hydrometallurgy and the hope that this would be solved by solvent extraction has not yet been fulfilled. With chloride solutions, advantage may be taken of the ability of cobalt to form anionic complexes with the chloride ion. It can then be readily separated from nickel, which does not form stable chloro complexes, by extraction with a suitable long chain amine. However, in hydro metallurgical operations, sulfate solutions are generally obtained in which no extractable anionic species are present. Thus, the possibility of using cationic extractants must be considered, and in this paper attention is directed to the use of carboxylic acids. The method of separation studied has been termed exchange extraction, which involves replacement of a metal in the organic phase with a more acidic metal in the aqueous phase. Thus, (BR2).+ (Az+)aqt=(AR,).+ (B2+)aq (I) where metal A is more acidic than metal B, R represents the acidic radical derived from the acid RH, and the subscripts e and aq refer to the organic and aqueous phases, respectively. Ashbrook and Ritcey' have used this method for the separation of cobalt from nickel using the sodium salt of di-2 ethyl hexyl phosphoric acid, which preferentially extracts cobalt. Some nickel is coextracted, and this is removed by exchange with cobalt ions in the feed solution by suitable countercurrent operation in a pulsed column. Much work has been carried out by a number of workers in Russia on the general use of exchange extraction for the separation of metal ions using car-boxylic acids. Gindin et aL a have demonstrated that this technique could be applied to the separation of nickel from cobalt using a C--C. carboxylic acid and have applied the technique to the production of high purity cobalt solutions for electrolysis. Further worka was concerned with the development of a process for the separation of nickel from cobalt in a pulsed column. This system permitted the separation of iron and copper from nickel and cobalt in one system. The procedure involved center feeding with acid backwashing at the top and alkali addition lower down the column. Thus the system operated under a pH gradient and the metals were distributed in the column in the order of their basicities. A similar application was studied by Gel'perin et al,4,5 for the removal of copper and iron impurities from a nickel anolyte by means of a C10-C,12 fatty acid fraction. Ginden et al,' and Fletcher and Wilson' have studied the effect of pH on the extraction of a number of metals with carboxylic acids. These studies showed that metals such as iron, copper, lead, zinc, nickel cobalt, and manganese are extracted at pH values close to the pH of hydroxide precipitation. Nickel is extracted at a slightly lower pH than cobalt and thus the nickel/cobalt separation factor has a value not much greater than 1. More basic work on complex identification has been reported by Fletcher and Flett: by Tanaka; and Jay-cock and Jones." These studies have suggested that at low loadings in the organic phase, the nickel and cobalt carboxylates appear to be dimeric and solvated by free carboxylic acid molecules. As the concentration of metal in the organic phase increases, the complex changes and larger polymeric species are formed. In order to permit assessment of the potential of carboxylic acids as extraction reagents for separation of

Jan 1, 1971

By M. E. Tyrrell, Alan H. Goode

The application of a simple, two-dimensional computer technique for evaluating rock burst potential in cut-and-fill stopes was investigated. The principal purpose of the study was to compare the effectiveness of high-modulus fill and destressing as aids in the control of rock bursts. Two conclusions that are probably of general applicability are drawn. First, high-modulus fill is ineffective as a means of increasing the mine stiffness and acts to control rock bursts only if it supports enough load to reduce substantially the stresses on the unmined vein material. Second, destressing is most effective if it is performed when the vein material is near the point of failure.

Jan 1, 1975

THE research and policy committee of the Committee for Economic Development, a non-profit research organization composed of leaders in industry and the professions, including such prominent figures as Dwight D. Eisenhower, Paul G. Hoffman, and Charles E. Wilson, recently published a report entitled "How to Raise Real Wages." Since its founding in 1942 the CED has initiated many objective studies on matters of national economic policy, and has gained a fair measure of prestige from its activities. The CED's latest report cites the more than three- fold rise in real wages in the United States in the past 50 years and attributes the accompanying improvement in the standard of living to the great in- crease in production per man hour. The report states that in order for production to continue rising in the future with the attendant increase in real wages four basic conditions must be manifest: (1) better methods, (2) more capital, (3) better training of workers, and (4) better management. The report cautions that although prospects for increases in output per man hour are good "it is desirable that steps be taken to encourage such a rise."

Jan 8, 1950

By Charles W. Merrill

IF we follow the threads of the mining problems, upon which I have touched, we find them all leading to one great fundamental desideratum. The people of this State, of this Nation, and of this world must be brought to a better understanding of the basic nature of our industry-must be made more mineral-minded. It is my belief 'that there is not a man present among this earnest gathering of those interested in the mining industry, who has not a deep-seated and heartfelt desire that the existing unprecedented welfare and prosperity of the whole mass of American people be maintained not merely through our own generation but through the generations of our children and their children. In the decades to come there can be no question of the keenness of the foreign competition which we are doomed to meet, and in this great international contest that Nation which has the best balanced program of development and that broadness of vision in its governmental direction, which recognizes the necessity of a sympathetic attitude toward the upbuilding of such a broad pro- gram will be the Nation which will maintain and pre- serve that welfare of all of its people.

Jan 1, 1929

By MORTON WEBB

Discussion of the paper of Max Boehmer, presented at the Pittsburg meeting, March, 1910, and printed in Bulletin. No. 38, February, 1910, pp. 119 to 122. W. MORTON WEBB, Germiston, Transvaal, South Africa (communication to the Secretary*):-The experience of Mr. Boehmer in the Leadville district and his reputation as an engineer assure the interest of anything he may write on the ore-bodies of that district; and all engineers who have operated in Leadville will agree that the theory of the origin of the Leadville deposits, as given by Mr. Emmons in his famous monograph, does not adequately explain the genesis of all the deposits. The solution of the problem does not, however, appear to be quite so simple as Mr. Boehmer would make it; and the advance pamphlet issued by the U. S. Geological Survey, pending the completion of the main report, shows that there is still much ground for controversy. No doubt the later eruptives had a greater influence on the deposition of the ore-bodies than was thought at the time of the first investigation by the Survey; but it has always appeared to me that the influence exerted by these dikes was more in the nature of a physical than a chemical one. The weight of evidence in recent years is mostly in the direction of ascension rather than lateral secretion; and one of the strongest evidences is the fact that most of the ore-bodies lie under one of the comparatively impervious layers which help to make up the structure of these hills. On Iron hill I have found a very persistent white porphyry sheet, split off from the overlying porphyry and lying from 30 to 60 ft. below the main white porphyry and blue limestone contact. This sheet varies from a few to 50 ft. in thickness, and where found adds another "contact" to that region ; some of the largest ore-bodies on Iron hill lie immediately under this sheet. Above this is the main white porphyry and * Received Mar. 3, 1910.

Feb 1, 1911

Executive Committee, Board of Directors Augustus B Kinzel, Chairman, J L Glllson, Vice-Chairman, A W Thornton, Howard C Pyle, Grover J Holt Finance Committee, Board of Directors Andrew Fletcher, Chairman, J S Vanick, Gall F Moulton Investments Gail F Moulton, '60, Chairman, Henry Krumb, '59, J Loveloy, '61, C R Dodson, ex off as Treasurer, Andrew Fletcher, ex off as Chairman, Finance Com¬mittee Endowment Andrew Fletcher, Chairman, N G Alford, H DeWitt Smith, W J Coulter, J V N Dorr, R B Gilmore, J B Haffner, O H Johnson, D H McLaughlin, J R McMillan, L F Reinartz, C E Weed, Wilfred Sykes, J R Suman Honorary Memberships H DeWitt Smith, '59, Chairman, C E Reistle, Jr, '59, Grover J Holt, '59, L F Reinartz, '59, M L Haider, '60, D H McLaughlin, '61, John M Lovejoy, '62, Augustus B Kinzel, ex off as President

Jan 1, 1958

By A. C. Fieldner

THE older coal chemist had a much simpler conception of coal than we have today. To him coal was a mineral composed essentially of carbon, hydrogen, oxygen, nitrogen, sulfur, ash, and water, in various proportions. His studies on the constitution of coal were directed along the conventional lines of proximate and ultimate chemical analyses and making deductions from these data without any real appreciation of the fact that coal is a conglomerate of various chemical compounds, including many of the most complex structures known to organic chemistry. The view of the modern coal chemist is well expressed by Franz Fischer, I who says that while proximate and ultimate analyses are important both from the scientific and technical point of view, they tell the chemist no more concerning the number and kinds of chemical compounds that constitute coal than the reader would learn of the contents of a book if told that the printed contents consisted of 15 per cent. of the letter "e," 5 per cent. of the letter "n," 1 per cent. of the letter "g," 4 per cent. of the letter "b," etc. As the reader must have the grouping of letters into words and words into sentences, so the chemist must have the grouping of atoms into molecules and the proportion of each molecular compound in the coal aggregate before he acquires an adequate knowledge of the constitution of coal. Modern investigators2 are laying the foundation of a new chemistry of coal based on the biochemistry of plants and the chemical changes involved in processes of fermentation and decay. As

Jan 5, 1925

By H. H. Stout

THE high copper price during the war stimulated the capacity to produce far beyond a possible normal consumption. The curves in Fig. 1 show this. The line YZ indicates, what the world production and consumption of primary copper nor-mally would have been, had not the 3 war upset the rhythm of industry. Granting that the maximum world production of 3,150,000,000 lb. in 1917 was obtained by crowding both the equipment and the grade of ore mined, yet in many instances addi-tional capital was invested, upon which the producer will be driven to earn at least a reasonable interest. During the period of deflation, or C liquidation, which we have entered, the consumption of copper will nat-urally be below the normal. Fig. 1 shows the actual consumption ex-pressed-in per cent. of normal : 1919, 96 per cent.; 1920, 94 per cent.; 1921, 70 per cent. The copper industry, consequently, faces: (1) Potential over-production capacity; I (2) Diminished consumption. To deny the existence of these factors would be illogical. To minimize the menace of this potential producing capacity might lead to regret. All past attempts at artificial control have not proved very successful. Obviously the remedy is to increase, if possible, the consumption of copper to a point where these factors cease to be dangerous. In ultimate analysis, this means: Produce an article so cheap and so good that no one can afford to use substitutes. The problem can be solved by: (1) Re-ducing price; (2) Improving product offered.

Jan 11, 1922

By J. M. Woodall

GuAs crystals which have been grown in quartz boats by the horizontal Bridgman method in the pvesence of Ga20 vapov have beetz found to have carrier and donor distributions which do not correspound to those expected from simple dopant seg-vegation during directional freezing; Instead, the carrier distribution is determined by the heat-trentnzent history of the crystal, while the donor distribution, zohiclz is principally due to silicon, is fixed by the pozuth rate, the geo)tlet.ry of the crystal growth vessel, and tlze initial Ga20 pressure. WHEN semiconducting materials are made into doped crystals by the normal freezing method,&apos; they usually exhibit doping variations along the growth axis. If a) there is no dopant diffusion in the solid, b) the dopant is distributed uniformly in the melt, and c) the distribution coefficient, k, does not vary with composition, then the doping variation along the growth axis is represented by the equation: where C is the doping level in the solid at a point where a fraction g of the original liquid has frozen, and Co is the mean concentration. When the dopant is either a singly ionized shallow donor or shallow acceptor, C also represents the carrier concentration. Even though this equation accurately describes the dcping profiles of a large number of normal freeze systems, there are several special systems for which Eq. [I] does not apply. One such system is the horizontal Bridgman method for preparing oxygen-grown GaAs crystals using quartz vessels. Several workers2"* have shown that GaAs crystals grown by the horizontal Bridglnan method using quartz vessels are generally contaminated with silicon in concentrations in excess of 5 < 10lG atoms per cu cm. This contamination is ascribed to a reaction: occurring at the walls of the crystal-growth vessel which liberates silicon into the melt and Ga2O vapor. It has been shown4 that this reaction, and, hence, the silicon contamination, can be suppressed by the addition of oxygen to the crystal-growth apparatus. It is the purpose of this paper to describe a special apparatus capable of yielding single crystals of GaAs grown in the presence of oxygen and to describe both the kinetics of silicon suppression in this system and the relationship between the carrier concentration profile and the silicon concentration profile. EXPERIMENTAL-CRYSTAL GROWTH A schematic diagram of the apparatus used in the oxygen addition experiments is shown in Fig. 1. The most important features of this apparatus are: a) the use of a sand blasted quartz boat, h) a quartz rod of length 1, with a hole of cross section A, that is placed near the boat to limit the free space volume V, over the melt during the growth, and c) the temperature gradient at and near the solid-liquid interface. Sand blasting the boat is necessary to prevent wetting of the melt. The quartz rod retards the diffusion of the GazO vapor away from the melt to the colder portions of the ampoule. A crystal is prepared by first loading a 5.5-in. boat, which has been cleaned in aqua regia, with 40 g of 99.9999 pct Ga along with 1 to 8 mg of Ga203 powder. GazO3 is a convenient source of oxygen since it reacts with gallium at the melt temperature to form Ga20 vapor, the species which apparently controls the suppression of silicon contamination. The loaded boat, the quartz rod, and the 99.9999 pct As are placed in the ampoule as shown in Fig. 1. Generally, GaAs seeds were not used since most of the unseeded growths resulted in monocrys-tals. The ampoule is evacuated to 10-5 Torr and sealed off. The GaAs melt is synthesized by placing the ampoule into a two-zone horizontal Bridgman furnace. The two zones are separated by several sandwiched layers of -in. Fibre-Fax board drilled with holes slightly larger than the OD of the ampoule. This causes a very large temperature gradient between the two zones, which is necessary for single-crystal growth. The two-zone furnace is mounted on a stand fitted with a roller bearing which allows uniform motion of the furnace in a horizontal direction. A uniform velocity of the stand is achieved by the use of a windlass device which winds up a wire attached to the stand. Movement of the solid-liquid interface is accomplished by fixing the position of the ampoule and moving the stand. Growth rates investigated in this experiment were between 0.4 and 1.2 in. per hr. The composition of the melt is fixed by maintaining an arsenic reservoir at 618°C. The stand is moved away

Jan 1, 1968

By William R. Webster

This is a subject which our Institute has made peculiarly its own. In the first volume of its Transactions the analysis of steel received attention, and every subsequent volume has borne witness to the acuteness and industry of our members in the investigation of this subject. The keynote mas struck, in this as in so many other lines of progress, by A. L. Holley, in his paper on " Tests of Steel," read at the Easton meeting of October, 1873 (Trans., ii., 116)—an essay which may rank as a classic by reason of .its elegant form, logical force, and clear prevision of all the bearings of its theme, Taken together with the brief report of the discussion which followed it (in which Dr. Drown emphasized the effects of heat-treatment and mechanical handling, and Dr. Sterry Hunt the importance of minute variations in chemical composition, and of possible isomeric and allotropic conditions), it constitutes, after the lapse of twenty-five years, an admirable and adequate introduction to the long list of technical papers which have succeeded it. Three years later came the epoch-making papers of Dr. C. B. Dudley on the relation between the chemical composition and physical properties of steel rails, which, with the voluminous discussion they evoked, constitute a special volume, published by the Institute, and full of useful suggestions. If Dr. Dudley could be induced to resume this investigation, he would doubtless be able to solve many points still uncertain or disputed. But I cannot undertake to review the history of this subject, as represented in our Transactions—still less to restate all the contributions to it which have been made in books or in papers before other technical societies, since the initiative was taken by the Institute. My more modest purpose is to indi-

Jan 1, 1899

By J. E. Johnson

The general construction of blast-furnaces has undergone no radical change in more than a generation. When the old style of masonry construction was replaced by the steel shell, the masonry piers were simultaneously replaced by columns, never lese than 6 and frequently 12 or 16 in number, set under the mantle-ring. These columns were at first unvaryingly made of cast-iron, but in more recent years have frequently been made of structural steel. The furnace itself has recently been the subject of radical changes; in some cases the thin-lined construction has been adopted for the whole furnace, and in other cases it has been adopted for a zone immediately above the bosh, raising the mantle several feet to make this possible, but still the style of construction with columns set immediately under the mantle has been universally followed. In spite of the apparent fixity of this type of construction it is open to grave disadvantages from the operating point of view, which may be briefly outlined as follows: The slope of the bosh and size of the crucible are such as to leave scant room inside the columns for the necessary water-piping, etc. The bustle-pipe must necessarily be outside the columns and the penstocks have to pass between them, with the result that the columns are frequently much in the way when changing the tuyeres or otherwise handling the penstocks. Moreover, the hearth-jacket requires a diameter but little smaller than the circle of the inside of the columns, and as a result the cooling-water ditch for protection against breakouts is exceedingly limited in width. As a consequence of these conditions, when any work requires to be done around the furnace, such as changing a tuyere or working on the cooling-water pipes, the amount of room left between the columns, pen-

Jan 1, 1913

By Charles S. Barrett

Metallurgists are making use of the stereographic projection to a steadily increasing extent. In the last five years no less than 20 papers in American metallurgical journals alone have employed the stereographic projection; recent books on physical metallurgy, plastic deformation, X-rays and their applications, and crystal structure use it. Mineralogists have used the stereographic projection for many years in the description of symmetry classes and crystal planes, for it presents an accurate, easily understood plot of any angular relations in crystals with all unessential features eliminated (such as the accidentally determined size and shape of crystal faces). In metallography and physical metallurgy the projection is much used for the analysis of markings appearing on polished grains: slip lines, twins, cracks, structures formed by precipitation, magnetic-powder patterns, etch pits, etc. Data from certain types of X-ray photograms are most conveniently analyzed by its use, particularly those for determining the orientation of single crystals or the preferred orientation of grains in an aggregate. Calculations of how to tilt or cut a crystal parallel to a certain crystallographic plane or to reflect X-rays from a certain plane are rapidly carried out. It has been adopted almost universally to the exclusion of other methods by those studying the deformation of metallic crystals, save where the accuracy required is greater than a few tenths of a degree. Any directional property in a crystal or polycrystalline material can be shown on a stereographic projection; for example, the modulus of elasticity, yield point, etc. It has been repeatedly called to our attention that there is need of an elementary explanation of the principles and methods of stereographic projection, covering all the common applications in the field of metallography and physical metallurgy. The following contribution is an attempt to fill this need. The description of each method is supplemented with references to publications in which the method has been used. For convenience to the reader, these illustrative references are chiefly in American journals, particularly the publications of the American Institute of Mining and

Jan 1, 1937

By H. F. Johnson, C. S. Harloff

The Nichols series system of electrolytic copper refining has successfully maintained its strong competitive position in the copper-refining industry of today; therefore the improvements made in accomplishing this result are of interest. While additional interest would lie in specific comparisons of results obtained in series operation with those in multiple, we have refrained from such a comparison because it can be fair to both only when they are operating under similar conditions on the same grade of materials. Historical The Nichols Copper Co. started a small refinery at Laurel Hill, using its present system, about 1892. The details of the process in its early stage of development were kept strictly secret, so that no information was published or interchange of ideas permitted with the staffs of other copper refineries, where the multiple system was being developed at the same time. However, the fundamentals of the process and type of cell used today differ very little from their earliest form. All operations including loading and unloading of tanks, and all transportation as well, were carried on by hand. The plant remained in this condition with a gradual expansion taking place until the World War forced such a rapid development that little time or thought could be devoted to modernization or mechanical improvement requiring careful design or detailed planning. Considerable progress was made, however. (1) Large refining furnaces were developed. (2) The old expensive air-lift type of circulation was abandoned in favor of the present system. (3) Operating technique was gradually developed to a high point of efficiency. (4) Tank construction and lining were greatly improved, the first concrete tank being installed in 1915. (This tank is still in operating condition.) (5) A new power plant was constructed. (6) Fuel oil was substituted for lump coal on the refining furnaces. (7) Mechanical casting of the finished product was accomplished. During this entire period the plant was particularly fortunate in receiving only high-grade, clean copper bullion coming principally from the Phelps Dodge mines in Arizona. This, together with the lack of

Jan 1, 1934

By Robert H. Richards

The adaptation of European methods of concentrating ores to suit the conditions of this country has followed the lines that simplify machinery, diminish labor and increase capacity. Noteworthy instances are the substitution of hydraulic classifiers for the last one or two trommels in the series, and the substitution of a distributing-tank for the slimes in the place of the Spitzkasten. The question may be fairly asked, At what point do losses become serious in consequence of these changes? It is to study this question that the investigation herein described has been undertaken. After the losses are located and the methods of stopping them are pointed out, it will then lie with the individual mill to decide whether or not the plans proposed will save suficient value to warrant their adoption. In the discussion of sorting followed by sizing, as the terms are used in this paper, me have to deal with the preparation of slimes by the Spitzkasten for subsequent washing upon the slime-table. The Spitzkasten, or pointed box, is an inverted hollow pyramid, generally of wood, usually with four faces or sides coming together in a point below. The sides can have, according to Rittinger, a minimum angle of slope of 50" with the horizontal. The feed-water carrying fine slimes (less than 0.01 inch, or 0.25 mm. in diameter) for treatment is fed at one end and carefully distributed over the whole width. The outlet is over the opposite end. The water-current passes direct from inlet to outlet, and has usually been regarded as a surface-layer pass-

Jan 1, 1898

By Walter J. Johnson

The coals in northern Wyoming and Montana are free-burning and non-caking and range from lignite to bituminous C in rank. Strip and underground mining are employed to supply railroad, utility, industrial, and domestic fuel. The market area includes Iowa, Nebraska, Minnesota, North and South Dakotas, Wyoming, Montana, the Pacific Northwest, and western Canada. THE larger producing coal mines in northern Wyoming are located in the Powder River Basin lying between the Black Hills region of South Dakota, eastern Wyoming, and the Big Horn Mountains in north central Wyoming, see Fig. 1. The mines are located particularly in the area along the route of the Chicago, Burlington & Quincy Railroad from Gillette, Wyo., to a point approximately 15 miles northeast of Sheridan, Wyo. Fig. 2 is a graph of coal production in the state of Wyoming from 1918 to 1951. Across the Big Horn Mountains lies the Big Horn Basin, situated between the Big Horn Mountains and the Rocky Mountains proper. Mining in the Big Horn Basin is almost entirely confined to a small area known as the Gebo Field, near the town of Kirby, which is located on the Chicago, Burlington & Quincy Railroad. This paper will describe present operating areas, making only brief reference to the history of mining and marketing primarily because of the large area to be discussed. The coal beds presently mined in the Powder River Basin are all of Tertiary age and are of Fort Union and Wasatch formations of Paleocene and Eocene ages, see Fig. 3. The Fort Union formation, consisting of 2000 to 3200 ft of alternate sandstone, shale, and coal, is divided from oldest to youngest into the Tullock, Lebo Shale, and Tongue River members. Most of the mineable coal is in the Tongue River member, which is 500 to 800 ft thick. The Carney coal bed, varying from 7 to 20 ft in thickness, is considered the base of the Tongue River member. About 85 ft above the Carney is the Monarch bed, ranging from 18 to 42 ft in thickness. At approximately 210 ft above the Monarch is what is locally known in the Sheridan district as Dietz No. 3 bed, which varies from 12 to 30 ft in thickness. One hundred feet above the Dietz No. 3 is Dietz No. 2 bed, which is 7 to 12 ft thick. At about 100 ft above the Dietz No. 2 is Dietz No. 1 bed, 7 to 15 feet in thickness. Two hundred and fifteen feet above Dietz No. 1 is the Smith bed, approximately 5 ft thick. One hundred twenty-five feet above the Smith is the Roland bed, which is estimated to be approximately 13 ft thick. The Roland bed is considered the base of the Wasatch formation, which in the Powder River Basin is 1000 to 3500 ft thick and is composed largely of shale, sandstone, and coal. The foregoing measures are the only ones above the Tongue River member that have been mined in the Sheridan field. To the east of the Sheridan field, particularly in the area of Gillette, the Roland bed is considerably thicker and is considered the thickest and most extensive coal bed in Wyoming, reaching a maximum thickness of 106 ft. From 125 to 225 ft above the Roland lies the Arvada bed, average thickness 9 ft. Three hundred seventy-five to four hundred feet above the Arvada is the Felix bed, which reaches its maximum thickness of 30 ft near Echeta on the Chicago, Burlington & Quincy Railroad. East of the Powder River the bed averages more than 10 ft in thickness, but it thins in a northwesterly direction. The highest mineable coal in the Powder River field is the Healy bed, about 400 ft above the Felix bed and exposed only in the highest parts of the area where much of it has been burned along the outcrop. Where it has not been burned, the thickness at most of the outcrops is 10 to 15 ft.

Jan 1, 1954

By Kenneth Seaver

(San Francisco Meeting, September, 1915) INTRODUCTION IT is rather gratifying that in the field of the manufacture &apos;of refractories, in which, as a whole, foreign practice has surpassed us, the United States stands pre-eminent in the making of silica brick. In some instances European manufacturers have refused point-blank to credit the possibility of making to such specifications as are common with us, until the actual &apos;completed shapes were shipped for inspection. But both the manufacturer and consumer in foreign lands are now frankly learning from us, and benefiting by our advanced practice in this field, as is evidenced by the orders placed here and the efforts put forth abroad to come up to the standard of American-made material. In no metallurgical operation has the employment of silica brick spread with. such leaps and bounds as in the building of plants for the carbonization of coal, particularly in the byproduct coke oven. Today, in practically all types of oven, the structure above the floor level (except the facings) is of silica, while in the recuperative and in some regenerative types, its use is extended to that portion of the oven below the floor as well. By reason of the fact that there are a number of classes of refractories of higher silica content than the usual so-called fire-clay brick, there is sometimes a misunderstanding as to the class of material referred to as "silica" brick. We here refer only to a brick having a silica content of 94 per cent. or more and made usually from quartzite rock with a small percentage of lime as a binder. The term "silica" brick is sometimes rather loosely applied to brick front highly siliceous clays, or to a quartzite refractory of mingled fire-clay and quartz rock; but such products are not considered in this discussion.

Jan 9, 1915

By W. E. Keck, W. C. Lowry, G. C. Eggleston

The potential iron ores of Michigan can be classified from the stand-point of the predominant impurities into siliceous, sulphurous and phos-pllorous ores. Research on the flotation of each of these classes of ore was carried out in the following manner. The flotative properties of the valuable minerals of iron and of the worthless and deleterious ones were first determined under carefully controlled conditions. This information was then applied to synthetic mixtures of these minerals, which simulated the potential ores. Finally, data obtained during the two foregoing stages of the investigation were used in the flotation beneficiation of samples of the potential ores. Hematite is the most important mineral of iron in each of the above classes of iron ores. This paper deals with a study of that mineral in the very nearly pure state. There are two varieties of the mineral—specular hematite and massive hematite. The latter is the principal variety, but the former is an impor-tant&apos; mineral of iron in some of the potential ores. Because of this condition, flotation research was performed with both varieties. This research consisted essentially of: (I) a survey of the literature on hematite flotation, (2) the preparation of pure massive hematite, (3) the preparation of pure specular hematite, (4) the development of a laboratory procedure and (5) flotation experimentation. For the purpose of this discussion, the results of previous work on the flotative properties of hematite can be summarized as follows: Specular hematite has been readily floated with terpineol and sodium oleate or heptylic acid1. Further, hematite has been likewise floated with a proprietary frother and oleic acid or other soluble oils2. Finally, lead nitrate, copper sulphate, silver nitrate, chromium nitrate, mercuric chloride, ferric

Jan 1, 1939

By G. C. Eggleston, W. E. Keck, W. C. Lowry

The potential iron ores of Michigan can be classified from the stand-point of the predominant impurities into siliceous, sulphurous and phos-pllorous ores. Research on the flotation of each of these classes of ore was carried out in the following manner. The flotative properties of the valuable minerals of iron and of the worthless and deleterious ones were first determined under carefully controlled conditions. This information was then applied to synthetic mixtures of these minerals, which simulated the potential ores. Finally, data obtained during the two foregoing stages of the investigation were used in the flotation beneficiation of samples of the potential ores. Hematite is the most important mineral of iron in each of the above classes of iron ores. This paper deals with a study of that mineral in the very nearly pure state. There are two varieties of the mineral—specular hematite and massive hematite. The latter is the principal variety, but the former is an impor-tant&apos; mineral of iron in some of the potential ores. Because of this condition, flotation research was performed with both varieties. This research consisted essentially of: (I) a survey of the literature on hematite flotation, (2) the preparation of pure massive hematite, (3) the preparation of pure specular hematite, (4) the development of a laboratory procedure and (5) flotation experimentation. For the purpose of this discussion, the results of previous work on the flotative properties of hematite can be summarized as follows: Specular hematite has been readily floated with terpineol and sodium oleate or heptylic acid1. Further, hematite has been likewise floated with a proprietary frother and oleic acid or other soluble oils2. Finally, lead nitrate, copper sulphate, silver nitrate, chromium nitrate, mercuric chloride, ferric

Jan 1, 1939

By C. H. Herty

The reactions that occur in the basic open-hearth process are complicated and are subject to many different factors such as temperature, slag composition and rate of boiling of the bath. It is difficult, therefore, to present an extended theoretical discussion of open-hearth operations without confusing the theory of the process with the application of the theory. This paper attempts to present some of the theory of the open-hearth process without mentioning theory at any point, simply giving some of the practical applications of results founded both on theory and practice and on experimental work both in small and large furnaces. It is hoped that an answer to a number of questions commonly asked by the open-hearth operator may be found in this paper. Discussion of the subject matter is taken up more or less in the order in which a heat ie worked, beginning with the oxidation of the scrap charged, sulfur absorption by the scrap, calcination of the limestone, and extending into the pig iron for the charge, the slags formed during the process, and some of the phenomena occurring in deoxidation of the steel and in its action in the molds. Oxidation of Scbap When scrap is charged into a furnace it immediately begins to oxidize, Oxidation is carried out by.three reactions: Fe + H20 + FeO + Hz (absorbs heat) (1) Fe + C02 + FeO + CO (absorbs heat) (2: Fe+ ½O2 + FeO (gives off heat) (3: The product of oxidation contains some Fe3O4, but FeO usually predominates on account of the iron present in close contact with the scale formed For a given type of scrap the amount of oxidation is controlled by thc fuel and by the excess air being carried in the furnace, the temperature 01 the furnace, and the length of time that the scrap is in contact with the furnace gases. In general, less oxidation occurs when the furnace is rur hot so that the scrap melts rapidly. More important in operation thar the two variables atmosphere and temperature, is the type of scrap being

Jan 1, 1929