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By Jack C. Haptonstall

This paper describes the analytical characteristics of Western subbituminous coal and the manner in which these characteristics apply to their use in a utility-sized steam generator. It compares these characteristics with those of typical Midwestern coal and Eastern bituminous coal. The paper also reviews in detail the design considerations that must receive attention when various blends of these three coals, or any combinations thereof, are planned to be used. This research paper describes variations in analytical and utilization characteristics when coals from different origins are blended in order to achieve a predetermined sulfur content for the purpose of predicting sulfur oxides emissions as they affect environmental regulations and the resulting alterations in utilization characteristics such blending would cause, and how such blends of coal would affect a utility-sized steam generator.

Jan 1, 1979

Prof. Frank H. Probert, dean of the College of Mining of the University of California, visited the mining areas in the devastated regions as a member of the Bureau of Mines committee, which is studying the problems presented in the rehabilitation of mines there. He says that the absolute destruction of the coal mines in the Pas de Calais section makes it-necessary to use either the Westphalia or the Saar valley coal. The Saar mines, however, produce a poor quality of coking coal: therefore, it will not be possible to operate blast furnaces very efficiently unless provision is made for the introduction of better coal. He believes

Jan 6, 1919

By William M. Baldwin

Jan 1, 1946

By William M. Baldwin

Jan 1, 1946

Jan 1, 1961

By Henry G. Granger

NOTHING in this paper is to be understood as even suggesting a moment's suspension of the splendid work now going forward on the Isthmus of Panama, except so far as it is related to the proposed locks. All the work already done, and all material purchased or ordered, would be available for the plan herein proposed. The situation and the problem concerned may be summarized as. follows : The scheme of a lock-canal through the Isthmus of Panama was adopted, as is well known, on two principal grounds-namely, the greater expense of a sea-level canal, and the longer time required for its construction. Of these, the latter is believed to have been the more influential. But further developments have diminished the weight of both, so that a reconsideration of the question is warranted. It is the purpose of this paper to advocate such a reconsideration-emphasizing the importance of certain objections to the lock-canal not mentioned or not duly appreciated in the report of those members of the International Board of Consulting Engineers who favored this form; showing the nature and bearing of the new facts developed; and, finally, proposing a combination of well-known methods and apparatus, which would, in my judgment, effect the construction of a sea-level canal in less time, and perhaps at no greater cost, than will be required for the remaining work on the lock-canal. I. OBJECTIONS TO A LOCK-CANAL. 1. Earthquakes. Two centuries ago Panama is said to have been destroyed by an earthquake. In 1882 a rather violent earthquake was felt at the southern end of the Isthmus. In 1898 I felt a slight shock near the present border-line of Colombia. In 1900 I felt three shocks at Quibdo, the head of navigation of the

Jan 1, 1909

By Jack C. Haptonstall

Abstract-Minas de San Luis, S.A. operates the old Tayoltita mine located in the Sierra Madre Occidental in Durango, Mexico. Yearly production is 55 000 kg (1.7 million troy ox) of silver and 1000 kg (31,000 troy ox) of gold from milling 165 000 t/y (181,900 stpy) obtained from fissure veins. A 4.4 km (2.75 miles) adit, to intersect the veins below existing workings, was completed in 1974. The adit and ancillary projects facilitated extensive mechanization of the mine, ramp development of it, integration of duplicate facilities and elimination of obsolete facilities. It provided a deep-level access for exploration and development of the veins, and resulted in a 25% increase in production with the same labor force. The cost of the in-house financed project was $3.4 million.

Jan 2, 1978

By William J. Priestley

Much time has been devoted, by metallurgists, to the study of steel after solidification and remarkable strides have been made in the heat treatment of steel, but less knowledge is available of the thermophysical activity of the constituents of steel prior to solidification in the mold. It is known that certain elements added to steel produce marked changes in physical properties, also that other elements added to steel produce similar changes, but we have only meager knowledge as 'to. how these elements combine in steel under different conditions of solidification. It is not sufficient to know, from chemical analysis, that a certain element is present in steel. We should know how this element is in combination with the other elements and whether the combination is such as will give the greatest physical properties. Certain elements go into solid solution with the iron, while others segregate to the grain boundaries and combine with the impurities collected there. Until it is known where an alloy produces the most beneficial effect and a means is determined for controlling its physical location by altering solidification conditions, or otherwise, we will not obtain the maximum value from our alloys. When molten steel freezes, it forms a heterogeneous mass of various crystalline constituents; and as the transformation of steel from a liquid state to the solid crystallized state is a critical step, involving as great a transfer of heat as any other operation in the making of finished steel, a variation in the rate of this heat transfer will have much to do with the arrangement of the various constituents in the solid state. The object of this paper is to show some of the effects on steel caused by variations in the rate of cooling in the ingot mold, particularly as to ingotism, segregation, dendrites, and intergranular material.

Jan 1, 1924

By J. Burns Read

IT IS the purpose of this paper to summarize, as far as possible, the metallurgical information and experience gained by the Ordnance Department, during the War, in the manufacture of artillery cartridge cases, to describe the tests to which artillery cartridge cases were put, and to summarize the knowledge and experience gained in this testing. The authors wish to acknowledge the aid given by manufacturers, army officers, and civilian employees of the Ordnance Department in obtaining these data. Artillery cartridge cases are cold drawn from circular disks punched from strips of rolled brass. The manufacture involves from 25 to 30 main operations, which are done almost entirely on a punch press. Descriptions of the operations have appeared in various periodicals and, therefore, will not be given here. After each cupping, or drawing, operation, except the last, the cases are annealed at from 540° to 650° C. (1000° to 1200°F.), to remove all the hardening stresses set up in the metal and to allow complete recrystallization. After each annealing, the cases are pickled in niter cake or sulfuric-acid solution and then washed in water to remove all traces of acid. In some instances, the cases are then immersed in a cyanide-salt solution, and afterwards rinsed in water, to remove the thin layer of copper that forms on the surface of the cases during the acid pickle. The last cold-drawing operation is followed, by the heading operation which, by flattening the head of the case on the outside, causes the metal to flow on the inside to approximately the proper finished dimensions. The mouth, or open end, is then annealed at 430° to 480° C. (800° to 900° F.) by immersion in a salt bath or by gas flames. After being washed, the cases are tapered, when they are ready for machining, inspection, and testing.

Jan 4, 1922

Jan 1, 1905

By S. F. Shaw

Tars paper is a review of the principal details of cyanide practice in several of the modern plants in America, mainly during the year 1908. Two of the mills, the Goldfield Consolidated and the Vets, Colorado, are not yet prepared to give data, the former having started about Jan. 1, 1909, and the latter not yet being completed. These two mills embody most of the latest methods and are therefore described as far as possible. I. CRUSHING. The principal methods of crushing ores for treatment by the cyanide process are with gyratory and jaw-crushers, stamps, Bryan and Huntington mills, and tube-mills. The first stage is usually done by gyratory or jaw-crushers, in a few cases sup-\

Jul 1, 1909

By W. H. Caruthers

ECONOMIC utilization of all by-products has long been the goal of American industry. One of the first groups that was popularly supposed to have achieved its aim was the meat-packing industry, which reputedly found a use for everything except the squeal of the hog. To the metallurgist, slag has always been the principal wasted by-product, representing a loss not only of material, but of heat. Slag does not possess many qualities that appeal to man's imagination or suggest a romantic influence on the daily life and progress of a community or nation. It is a bulky product, and space for its disposal within reasonable hauling distance of a smelter is not always available; the iron-ore smelter especially has been wont to find space for slag disposal at a premium. Therefore, the success that has been attained in recent years in finding a use for iron blast-furnace slag is notable. It has become a vital economic factor in the construction industry in areas where it is available. Its use may suggest further possibilities of an economic outlet for the slags from nonferrous smelting as well.

Jan 1, 1940

By Charles W. Perry

The options of enhanced oil recovery, coal syncrude, and shale syncrude are compared by approximately equivalent economics. The physical constraints for the major enhanced oil recovery processes are described, followed by new estimates of cost. The range for all three options in terms of light syncrude equivalent are $22 to $40 per barrel in 1980 dollars.

Jan 1, 1982

By Johann F. Kerl

Autogenous batch grinding tests were performed in laboratory-scale tumbling mills with magnetite, limestone, and sandstone pebbles. The influence of pebble size, feed size, mill speed and loading, and grinding time on the fineness of grinding was investigated. Comparisons were made with the results from ball mill grinding experiments.

Jan 1, 1972

By F. N. Flynn

- Introductory IN 1882, The Arizona Copper Co. Ltd., acquired producing copper mines at Metcalf and Morenci (locally called Longfellow). Metcalf is situated a distance of 7 miles, and Morenci a distance of 6 miles from the general office of the company at Clifton, Ariz. A reduction works with five blast furnaces was built in the center of the town of Clifton in 1884 and operated until January, 1914. Concentration of oxidized ores was begun in 1890-1891, in a mill built adjoining the smelter, and in October, 1893, a leaching process was started for treating tailings from the oxide mill. A sulphide concentrator with 300 tons capacity was built at Clifton and started treating chalcocite ores in July, 1896. This was the first mill to treat low-grade copper-sulphide ores successfully. Another concentration mill for sulphide ores was erected at Morenci in 1900. The, sulphide mills are now being remodeled to treat ores by concentration and flotation, with a capacity of 4,000 tons at Morenci and 500 tons at Clifton. The leaching plant has not been running since September, 1914. The average yearly production from this company's mines and reduction works from 1885 to date has been: Pounds 10 years ended 1894 6,864,902 10 years ended 1904 20,439,614 10 years ended 1914 : 32,665,905 Part of year 1915, to Sept. 12 30,206,106 4 months of 1916, to June 15,964,840 June, 1916...: ? 4,900,000 Construction on a new smelting plant was started in February, 1912, and finished in February, 1914. In the Transactions, vol. 49, E. Horton Jones published "Unit Construction Costs from the New Smelter of the Arizona Copper Co., Ltd:," which fully describes the construction of this plant, with details of costs.

Jan 9, 1916

By Clinton M. Young

(Pittsburg Meeting, March, 1910.) I. INTRODUCTION. THE experiments herein. described were carried on in 1908-9 . by the State Geological Survey of Kansas. Some months before taking up work on black powder the Survey had resumed work on an interrupted investigation of explosions in coal-mines, a subject which is engaging the attention. of numerous investigators. An unusual number of serious disasters has directed to. the subject a study which discloses the disquieting fact that, in the. United States, the ratio of lives lost per ton of coal mined has been on the increase. Methods of coal-mining have changed to some extent with the great increase of output, attained in, comparatively recent years. These changes involve the working of very extensive mines, with increased difficulty of ventilation, increased accumulation of coal-dust, and. a very great increase in the amount of explosive used.. . This last point assumes truly startling proportions when it is carefully observed. In the fields of the Middle. West it is not now uncommon for a miner to use six ,kegs (150 lb.) of black powder in a "pay" of two weeks, while within the memory. of men still active, one keg (25 .lb.) would last two men for a " pay." So. great has . the use of explosives become in some fields that the skilled coal-miner is hard to find, and the coal is not mined, but blasted. A preliminary study of the subject. of explosions in coal-mines has. led to the belief . that the use of, large -quantities of explosives, in some cases by slightly-trained men, had not been * Associate Professor- of Mining Engineering, University of Kansas, Lawrence, Ran.

Aug 1, 1910

Jan 1, 1925

By Stewart R. Wallace

Members of the Society, it is a very great honor for me to be here today and to have the opportunity of telling you about some things that have been accumulating in the back of my mind for some time. Before attempting to do so, I should acknowledge my debt to the many people who are responsible for my presence here this afternoon. To do this properly, however, would consume much of my allotted time and I will therefore mention only two men, both of whom were directly involved in the discovery of the Henderson ore body. The first of these was Robert Henderson, now dead, who at the time the work was going on was vice president of Western Operations of the Climax Molybdenum Co. Truly, he provided the environment that permitted the exploration program to function effectively, and the deposit appropriately bears his name. The second man I meant to mention was resident geologist at Urad at the time of the Henderson discovery. I think I should explain right here that the Urad ore body and the Henderson ore body, although entirely separate, are closely related deposits, and that both are located at Red Mountain in Clear Creek County, Colo.

Jan 6, 1975

By C. R. Hayward

CARLE R. HAYWARD.-I do not want it understood that I think that the conclusion that the time of tempering temperature is immaterial has been definitely proven, but since these are the first definite figures put out, I thought before continuing on more work ourselves, it would be well to present them as progress and for information. J. A. MATHEWS, Syracuse, N. Y.-I think that if Prof. Hayward would consult the paper of Profs. Barus and Strouhal,1 1885, he would find about 250 pages, mostly figures, on this subject, in which they investigated the tempering effect by electrical and magnetic methods. There are so many figures in the paper that it is very difficult reading. One point particularly brought out was that even at a low temperature, such as the boiling point of alcohol, about 60° C., there is a tempering effect, increasing up to 4 hr. One reason they obtained those results, with which the present authors are at variance, was that they started with a high-carbon steel which hardens thoroughly, whereas the steel Prof. Hayward and his collaborator used was a comparatively mild steel which does not take a great deal of hardening. About 3 years ago Mr. Stagg and I published 2 a few figures bearing on the same subject, but we used .a low-carbon alloy steel of high tempering qualities and found a great deal of improvement, particularly in ductility, by continuing the drawing up to 4 hr. We used a chrome-vanadium steel showing after heat treatment 250,000 tensile strength. On short drawing, we got almost no ductility, but by continuing to 4 hr., we raised it to 12 per cent. I believe Prof. Hayward's results are due to using comparatively mild steel, whereas Prof. Barus used drill rod and carried out a, wonderfully exhaustive

Jan 4, 1917

By Frank G. Breyer

THE .following developments in the zinc field during 1935 are listed in the order of their importance. Each will he amplified in later paragraphs. In the field o f Metallic Zinc: (1) Construction of further continuous vertical retort smelting capacity in the United States and Germany. (2) Expansion of fractional distillation capacity in the United States. (3) Great expansion in the zinc-base die-casting industry in the United States and abroad. (4) Wide acceptance of heavy galvanizing by the steel industry. (5) Construction of the first commercial wire electroplating plant for putting on heavy coats of pure zinc. (6) Firm establishment and appreciable expansion of the practice of using zinc dust as a reducing agent in the organic chemical industry.

Jan 1, 1936