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By Harold A. Linke

THE following article presents notes and data compiled and computed by the writer for use in the determination of: size and slope of mill launders, details of junction boxes and downspouts, and distribution of pulp. It also includes pulp formulas, volume of discharge through bushings, paths of discharging streams, banking of turns and curves. In the design of a concentrating mill, the draftsman usually considers launders to the extent of providing ample "head" for transmission of pulp from one department of the mill to another. The superintendent of construction aims to build his launders wide and deep, and on a slope steep enough to ensure positive flow. So launders are laid generally on too steep a slope, with the result that the repair gang works to maintain launder bottoms and sides against the erosive action of the conveyed pulp. To this end many kinds of liners have been devised: concrete, mastic, white iron, glass, rubber. True, the reduction of slope to the point where a pulp will flow with minimum wear, will minimize labor and expense; but when the desired slope is not predetermined, the millman hesitates to readjust his launder slopes by cut-and-try methods. To the end that the desired size and slope may be found readily, the writer has: (1) conducted experiments with pulps of different specific gravity, screen analysis and dilution; (2) gathered a few graphic data from standard reference works (such as Peele's Mining Engineer's Hand- book and Taggart's Handbook of Ore Dressing); (3) computed several tables; and compiled results that have proved dependable for Utah Copper ore. It is quite possible that the following tables and graphs may not be applicable to all ores, but it is hoped that they may prove helpful, even in slight degree, in alleviating a portion of the trouble and migraine of some other millman.

Jan 1, 1939

Joseph K. Stone, Jr. (Kaiser Engineers, Oakland, Calif.)—I would like to compliment the authors on their clear presentation of the results of their study of the pneumatic processes. We hope that the Inland Management decision to make this information available to all will induce others to release additional valuable fundamental data which they have accumulated in the field. There are two points upon which we would like to comment. In the discussion of Table VII it was indicated that the "oxygen consumptions were about the same as has been reported for other oxygen steelmaking processes". This conclusion is apparently based upon the consumption of 2100 cu ft per ton shown in Table VII. The data in Table IV also permits calculation of 2520, 2280, 2250 and 2700 cu ft per ton in heats 1 to 4, respectively. These figures are in the same general range as those reported for the Kal-Do and Rotor Processes using Thomas iron, but considerably above the following figures for four of the operating L-D Process Plants while using iron which is similar to American basic iron: Donawitz 1760 cu ft per ton Adapted from Cuscoleca' LinZ 1900 cu ft per ton Trenkler & Hauttmann2 Dofasco 1850 cu ft per ton D. O. Davis:3 In addition to the differences between the consumption of gaseous oxygen in the Inland operation and in the L-D Process, there is another closely related difference. The L-D plants for which data are cited are using approximately 1 pct ore while the authors' process used about 7 pct of sinter. Assuming 65 pct Fe in the sinter, the difference amounts to 400 to 500 cu ft

Jan 1, 1959

By Harold Linke

THE following article presents notes and data compiled and computed by the writer for use in the determination of: size and slope of mill launders, details of junction boxes and downspouts, and distribution of pulp. It also includes pulp formulas, volume of discharge through bushings, paths of discharging streams, banking of turns and curves. In the design of a concentrating mill, the draftsman usually considers launders to the extent of providing ample "head" for transmission of pulp from one department of the mill to another. The superintendent of construction aims to build his launders wide and deep, and on a slope steep enough to ensure positive flow. So launders are laid generally on too steep a slope, with the result that the repair gang works to maintain launder bottoms and sides against the erosive action of the conveyed pulp. To this end many kinds of liners have been devised: concrete, mastic, white iron, glass, rubber. True, the reduction of slope to the point where a pulp will flow with minimum wear, will minimize labor and expense; but when the desired slope is not predetermined, the millman hesitates to readjust his launder slopes by cut-and-try methods. To the end that the desired size and slope may be found readily, the writer has: (1) conducted experiments with pulps of different specific gravity, screen analysis and dilution; (2) gathered a few graphic data from standard reference works (such as Peele's Mining Engineer's Hand-book and Taggart's Handbook of Ore Dressing); (3) computed several tables; and compiled results that have proved dependable for Utah Copper ore. It is quite possible that the following tables and graphs may not be applicable to all ores, but it is hoped that they may prove helpful, even in slight degree, in alleviating a portion of the trouble and migraine of some other millman.

Jan 1, 1939

By R. B. Campbell

One of the three power plants that will be in the Curecanti Unit of the Bureau of Reclamation's Colorado River Storage Project is the power plant at Morrow Point Dam. Presently under construction, the Morrow Point Power Plant is between Gunnison and Montrose on the Gunnison River in west-central Colorado. (Fig. 1). Morrow Point Dam will be a thin, double-curvature, concrete-arch dam, 465 ft high and will impound 120,000 acre-ft of water. Two 60,000-kw hydroelectric generators will be housed in an underground power plant in the left abutment just down- stream from the dam. The power-plant chamber will be an unlined opening 205.5 ft long, 57 ft wide and 65 to 134 ft high. The arch-type roof with a rise-to-span ratio of 1 to 4 will be supported with rock bolts and chain link fence. A description and discussion of the design considerations for the power-plant opening and rock bolt design are given by William H. Wolf, Gilbert L. Brown, and Ernest D. Morgan in "Morrow Point Under- ground Powerplant," ASCE Power Division Specialty Conference, Denver Colorado, August 18-20, 1965. The Morrow Point site is in a moderately active region of mild earth- quakes, as evidenced by recent earthquakes in 1960 and 1962. Therefore, the Bureau of Reclamation undertook an investigation of the effects on the underground power-plant chamber when subjected to an earthquake. The art of earthquake engineering has been directed primarily at developing methods of analyzing the nature of ground surface motions and designing surface structures to resist damage from vibrations impressed on the structure by the ground motions. The mechanism of straining an underground cavity by an earthquake

Jan 1, 1968

By F. L. Clerc

The lead and zinc region of SW. Missouri is interesting, not only by reason of the value of its output, which ranges in the neighborhood of ten million dollars a year, but even more because of the facilities which it offers for the study of certain forms of ore-deposits, of' which the loci and genesis are somewhat obscure. Although the mineral species found in the region are few and of common occurrence, crystallization has taken place on a generous scale, and unusual forms abound in many combinations, presenting examples of pseudomorphism, para-genesis, metasomatic replacement and the action of mineral-depositing and mineral-dissolving waters. For the mineralogist, lithologist, and specialist in certain lines of metamorphism, it has peculiar attractions, while the systematic geologist will perhaps find its chief claim to attention in the simplified problem it presents, in the study of ore-deposits. In addition to the phenomena above enumerated, it presents instances of well-developed comb-structure in the ores, fissures and faults, and slickensides—features usually associated with extensive movements in the earth's crust, and believed by some authorities to prove the deep-seated origin of the ores. In connection with these occurrences, the absence of all igneous rocks from this region is noteworthy and significant. For that reason, the simplified case presented by the Joplin region, from which these rocks have been eliminated as a factor, is specially valuable. Having had unusual opportunities to watch the development of this district, I have been deeply interested in the bearing of the revelations of the Joplin mines upon questions of universal importance to the science of ore-deposits; and it was to my great regret that the project of a meeting of the American Institute of Mining Engineers at Joplin, proposed in 1892, was

Jan 1, 1908

By V. R. Garfias, H. J. Hawley

FoR a number of years the senior author has been interested in the various geologic and engineering problems involved in the development of the petroliferous districts of northeastern Mexico, having in a previous paper* endeavored to present a summarized statement of the information relating to the geology and soil resources of this region. Of the many interesting geologic phenomena, perhaps those which have been the object of most speculation relate to the igneous intrusions which, in places, have a controlling influence on the accumulation of oil in commercial quantibies, a relationship which has been tentatively explained by various observers with as many interestingly different views. The authors of the present paper aim to record, in the course of a general discussion of the various viewpoints, some additional data, and present further tentative conclusions with a view to rounding out an up-to-date summary of the subject. The greater part of the area in question lies in the State of Vera Cruz, only a northwest fraction being in the State of San Luis Potosi. Vera Cruz is bounded on the north by the State of Tamaulipas, the northernmost of the Mexican States along the Gulf. The topography of the States of Tamaulipas and Vera Cruz and of Texas and Louisiana to the north, is controlled by the Gulf coastal plain which in northern Vera Cruz has an average width of about, 60 miles, the transitional topography between that of the rugged Banks of the Sierra and the lowlands of the coast being made up of a series of terraces and irregular hills and valleys. Geology and StRucture The greater part of the mainland of Mexico is made up of Tertiary and later effusive rocks and of sedimentaries of Cretaceous age. The igneous rocks form a belt from 150 to 300 miles wide, spurs of which shirt

Jan 1, 1918

By D. J. Jr. McAdam

PART I.-OUTLINE OF INVESTIGATION, DESCRIPTION OF METHODS AND MATERIAL Previous Investigation of the Influence of Stress on Corrosion IN 1917 Haigh1 presented evidence that under simultaneous corrosion and cyclic stress metals may fail at lower stresses than if the corrosion is prior to the cyclic stress. In 1926 the author, while investigating the cooling effect of water on the fatigue resistance of metals, found that under these conditions steel specimens fail at stresses far below the endurance limit.2 (By "endurance limit" is here meant the fatigue limit obtained with specimens as free as possible from stress concentration and corrosive influences.) This led to an investigation (at the Naval Engineering Experiment Station, Annapolis, Md.) of the influence of cyclic stress on corrosion. This investigation maybe divided into three parts. The first part was a general survey of the conditions necessary to cause complete failure under corrosion and cyclic stress of relatively high frequency. The entire process by which metals fail under these conditions was-called "corrosion-fatigue." "Corrosion-fatigue limits" for a large number of metals were determined and the relationships of these limits to chemical composition, heat treatment and physical properties were established. The conclusion was reached that corrosion-fatigue is due to the accelerating influence of cyclic stress on corrosion. Results of this part of the investigation were presented in five papers.2-6 The second part of the investigation was a preliminary study of the influence of cyclic stress on corrosion. Each experiment was conducted in two stages. The first was a corrosion stage in which the specimen was corroded under cyclic stress; the second was a fatigue stage, in which the previously corroded specimen was tested (without further corrosion) to determine its fatigue limit. The difference between this fatigue limit and the endurance limit was used as a criterion of the "damage" due to

Jan 1, 1931

By L. W. McKeehan

IT is no longer necessary, if it ever was, for your annual lecturer to apologize for including in his remarks frequent references to the arrange-ment of metal atoms in crystals and for basing his arguments that metals behave as they do upon their crystal structure. Neither will any objec-tion be raised because the large metallic crystals of which we will speak are hard to prepare and of negligible commercial interest. The particular set of physical properties we propose to discuss-ferromagnetic proper-ties-may require more justification. Very few in this audience are primarily, or even remotely, interested in the ferromagnetic behavior of the metals they handle. By no means all of you ever deal, by choice or by necessity, with metals which display any ferromagnetism at all, and even those who study or control ferrous metallurgy must usually depend upon electrical engineers for assistance in ferromagnetic applications. My excuse for talking about such an obvious specialty is, like all Gaul, divided into three parts. In the first place, the members of the com-mittee who select the annual lecturer must wish the speaker to confine himself to matters he has at least thought about before he prepares his speech. In the second place, the study of ferromagnetism in crystals has, as you will soon realize, suffered in the not-too-distant past from inade-quate metallurgy. Further progress probably depends upon proper use being made of the skill and knowledge of some members of the Institute of Metals Division who have not, before today, been asked to think about the problems presented here. Finally, there is at least a sporting chance that the ferromagnetic properties of a few metal crystals will give some insight into the more generally interesting properties which they share with nonferromagnetic metal crystals.

Jan 1, 1934

By D. J. McAdam

In 1917 Haighl presented evidence that under simultaneous corrosion and cyclic stress metals may fail at lower stresses than if the corrosion is prior to the cyclic stress. In 1926 the author, while investigating the cooling effect of water on the fatigue resistance of metals, found that under these conditions steel specimens fail at stresses far below the endurance limit.2 (By "endurance limit" is here meant the fatigue limit obtained with specimens as free as possible from stress concentration and corrosive influences.) This led to an investigation (at the Naval Engineering Experiment Station, Annapolis, Md.) of the influence of cyclic stress on corrosion. This investigation may be divided into three parts. The first part was a general survey of the conditions necessary to cause complete failure under corrosion and cyclic stress of relatively high frequency. The entire process by which metals fail under these conditions was called LLcorrosion-fatigue." Corrosion-fatigue limits" for a large number of metals were determined and the relationships of these limits to chemical composition, heat treatment and physical properties were established. The conclusion was reached that corrosion-fatigue is due to the accelerating influence of cyclic stress on corrosion. Results of this part of the investigation were presented in five papers.*-= The second part of the investigation was a preliminary study of the influence of cyclic stress on corrosion. Each experiment was conducted in two stages. The first was a corrosion stage in which the specimen was corroded under cyclic stress; the second was a fatigue stage, in which the previously corroded specimen was tested (without further corrosion) to determine its fatigue limit. The difference between this fatigue limit and the endurance limit was used as a criterion of the "damage" due to

Jan 1, 1932

By Ernest F. Burchard

Fluorspar is found in most of the states from the Rocky Mountains westward, and commercial production of the mineral has been reported from Arizona, Colorado, Nevada, New Mexico, Utah and Washington. The map in Fig. 1 indicates the general distribution of many of these deposits but it is by no means complete. In the summer of 1926 the writer examined certain deposits of fluorspar in Arizona, California, Colorado, New Mexico and Washington; in November, 1927, revisited the Jamestown, Colo., district, and in earlier years examined deposits in Colorado and New Mexico. Based on notes of his own and on descriptions and other data by H. A. Aurand, H. W. Davis, R. B. Ladoo, V. C. Heikes, W. D. Johnston, Jr., and by producers of fluorspar, he prepared the following brief descriptions of deposits and estimates of reserves of fluorspar, originally for the use of the subcommittee on fluorspar of the Joint Committee on Foreign and Domestic Mining Policy and on Industrial Preparedness respectively of the Mining and Metallurgical Society of America and the American Institute of Mining and Metallurgical Engineers. Descriptions of many fluorspar deposits in various western states and districts have been published. It is not feasible to summarize this literature here, but the appended bibliography will indicate to the interested reader what papers are available. Arizona Fluorspar has been reported as occurring in Arizona in the following localities: near Duncan, Greenlee County; near Naco, Tombstone, and Paradise, Cochise County; Black Mountain, Mojave County; 25 miles southwest of Tucson, and at Helvetia and Silver Bell, Pima County; near Mammoth mine, Pinal County; in Yavapai County, 7 miles from Aguila, and in the Bradshaw Mountains; and near Dome, Yuma County. Production has come principally from the Castle Dome district, Yuma County, with minor quantities from Greenlee, Pima and Yavapai counties. The writer examined deposits in the Castle Dome district, Yuma

Jan 1, 1934

By AIME AIME

TO attempt to say anything adequate about Eugene McAuliffe as a human being, engineer, or executive in this brief space is ridiculous, for one could extol his virtues at length in all three catagories. Too, one might dwell on his good humor, and also his modesty, for lie did not wish even these few words to be said, "having no illusions regarding either ability or achievement, not even blessed with good looks." Mr. McAuliffe was born in England just seventy years ago. Twenty years later he started at the bottom with the Northern Pacific, gradually being promoted to locomotive fireman, engineer, and so

Jan 1, 1936

By E. C. Pechin

THE Lucy furnace, owned by Messrs. Carnegie, Kloman & Co., and located on the Alleghany River, on the outskirts of Pittsburgh, is a splendid modern furnace, 75 feet high, and 20 feet bosh. She had been working well on low grade ores of about 50 per cent., producing daily 68 to 75 tons. There was on stock 500 tons of Republic ore, one of the purest and best of the Lake Superior ores, averaging over 68 per cent. of iron, which had been procured for the purpose of making a trial for Bessemer iron. This was charged by itself, and Mr. Skelding, the founder, reports that he did not succeed in getting a single cast when it came down, before the furnace chilled from the hearth to the top of the boshes, some 25 feet. Every effort was made to save her, without avail, and the disagree-

Jan 1, 1874

By Edmund C. Pechin

The Lucy furnace, owned by Messrs. Carnegie, Kloman & Co., and located on the Alleghany River, on the outskirts of Pittsburgh, is a splendid modern furnace, 75 feet high, and 20 feet bosh. She had been working well on low grade ores of about 50 per cent., producing daily 68 to 75 tons. There was on stock 500 tons of Republic ore, one of the purest and best of the Lake Superior ores, averaging over 68 per cent. of iron, which had been procured for the purpose of making a trial for Bessemer iron. This was charged by itself, and Mr. Skelding, the founder, reports that he did not succeed in getting a single cast when it came down, before the furnace chilled from the hearth to the top of the boshes, some 25 feet. Every effort was made to save her, without avail, and the disagree-

By Albert Sauveur

The instrument about to be described meets so perfectly the special needs of the metal microscopist that there eeeme to be little doubt but its merits must be readily appreciated by those who have had any experience in the microscopical examination of metals. The Microscope-Stand.—The microscope-stand proper, Fig. 1, consists of a microscope-tube, provided with both coarse and fine adjustments of the best construction, and with a draw-tube, rigidly mounted on a bar supported at both ends on substantial and firm cast-iron legs. The height between the table and the under side of the supporting bar is 5 in. and the distance between the supporting legs 12 inches. This arrangement affords free space below the objective for the examination of large epecimens of metals, such as full rail-sections, without detracting in the least from the value of the

Jan 1, 1912

By Philip J. Shenon

IN 1947 the mining industry strove desperately to regain operating normalcy. During the first part of the year the industry in this country was plagued with labor shortages, strikes, and portal-to-portal lawsuits. Then followed the uncertainty of Government policy with respect to subsidies and tariffs; and the long and bitter controversy as to whether we are a nation of mineral "haves" or "have-nots." As the year progressed the labor supply impoved somewhat and the Taft-Hartley law brought partial relief to strike-troubled industry. The uncertainty with respect to tariffs was partly answered by President Truman on April 29 when he announced the suspension of the 4¢ import duty on copper until March 31, 1949, and later, near the close of the year, by the announcement of the tariff agreement signed by the United Nations at Geneva. By this agreement tariff rates are to be adjusted downward, or "bound" at their present levels, for three years, on commodities amounting to some 60 per cent of United States trade. Effective Jan. 1, 1948 the rate of duty will be substantially reduced on ores, concentrates, or metals of zinc, aluminum, copper, manganese, tungsten, iron, steel, barytes, nickel, cadmium, and antimony.

Jan 1, 1948

EVERY forward-looking mining company realizes the need for employing graduate mining engineers so that there will be a supply of qualified men from which to draw for company officers, executives, and mine managers. The mining industry is competing today with numerous other fields of engineering for its supply of technical men, many of which are more attractive than mining because of better pay, living conditions, and well- regulated company training programs. The Ontario Mining Association and the mining companies of Ontario are conducting a postgraduate training plan which if adopted in the United States, might well encourage top quality men to study mining.

Jan 3, 1950

According to the June 27 issue of Business Week, Rep. Kearns (R., Pa.) introduced a bill in Congress along lines suggested by the National Society of Professional Engineers, to amend the Taft-Hartley Act to permit scientific, technical, and professional groups to discuss wages, hours, and working conditions with management-with the protection and support of the federal law. The article reports that the bill is opposed by a loosely knit group of professional and technical unions, the Engineers & Scientists of America. This group wants Taft-Hartley amended to make it an unfair labor practice for employers to discuss collective bargaining matters with professional organizations.

Jan 9, 1953

United Engineering Trustees, Inc. TAMES L HEAD, '50 E C MEAOHER, '52 R M ROOSEVELT, '49 The Engineering Foundation F F COLCORD, '50 E A PRENTIS, JR , '48 R M ROOSEVELT, '49

Jan 1, 1952

United Engineering Trustees, Inc. W. D. B. MOTTER, JR., '40 A. L. QUENEAU, '38 ALBERT ROBERTS, '39 The Engineering Foundation GEORGE D. BARRON, '40 F. F. COLCORD, '38 A. L. QUENEAU, '38

Jan 1, 1937

United Engineering Trustees, Inc. W. D. B. HOTTER, JR., '44 A. L. QUENEAU, '45 ALBERT ROBERTS, '43 The Engineering Foundation GEORGE D. BARRON, '44 F. F. COLCORD, '46 A. L. QUENEAU, '45

Jan 1, 1942