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By D. K. Deardorff, H. Kato

THE transformation temperature of hafnium from hcp to bcc is 1750° + 20 °C in contrast to previously published values by Duwez and fast2 which are believed inaccurate. The Bureau of Mines determined this value by measuring the temperatures at which a sudden decrease was observed in the electrical resistance of hafnium alloys containing up to 18 at. pct Zr, and then extrapolating the temperatures to 0 pct Zr. Duwez1 previously reported a transformation temperature of 1310°C, obtained by use of a rapid-cooling thermal-analysis technique. Later, Fast2 published a much higher value of 1950° 100°C based upon: a) his own determination of 1690°C for the beginning of the transformation range for hafnium containing 5.7 at. pct Zr, and b) his belief that lattice parameters reported3 for Duwez' hafnium indicated i contained 19 at. pct Zr and that the 1310°C value should be associated with that composition. Russell4 subsequently stated that Duwez and Fast probably were reporting their lattice parameters in different units and reassigned a value of 6.0 at. pct Zr to Duwez' hafnium. If this assumption were true, Duwez' hafnium was of approximately the same purity as Fast's, but his transformation value was considerably lower. The reason for this divergence is not known. Fast's value for hafnium containing 5.7 at. pct Zr agrees well with our data. McGeary5 determined a transformation value of 1660°C by metallographic examination of heat-treated specimens, but the zirconium content of his hafnium was not definitely established. The specimens used in this investigation were 1/8-in.-diam rods 6 1/2 in. long, fabricated by hot-swaging bars cut from arc-melted buttons. These buttons were melted from crystal bar hafnium and crystal bar zirconium. The chief impurity in the hafnium

Jan 1, 1960

By Fred C. Bond

SIX years have passed since the last grindability table was published.' In that time the list has been increased with many new tests, and the development of the new Third Theory of Comminution2 has made possible the reduction of all results to a consistent work index value. In this tabulation all grindability and crushability test results are given in terms of the work index, with formulas for reversion to the older units if desired. The average values for 57 different classes of materials are listed in Table I. The total number of work index values listed is 1211, and the overall average work index is 14.42. The complete tabulation, with each test listed alphabetically both under material type and under company name, can be obtained by writing to the Allis-Chalmers Manufacturing Co., Processing Machinery Department, Milwaukee 1, Wisconsin. The work index Wi is the calculated total work input in kilowatt-hours per short ton required to re- duce from theoretically infinite particle size to 80 pct passing 100 microns, or to approximately 67 pct passing 200 mesh. The work inputs required per ton for the same size reduction of different materials are directly proportional to their work indexes, and according to the Third Theory the work input per ton is inversely proportional to the square root of the diameter of the product particles. Where W represents the work input in kilowatt hours per ton, where F is the feed size, or diameter in microns of the square hole which 80 pct of the feed passes, P the product size, or microns which 80 pct of the product passes, and Rr the reduction ratio F/P, the work index Wi is found from Rr-l 100 When the work index Wi is known, the work input W required to reduce from any feed size F to any product size P is found from W = Wi ( Rr- 1 100

Jan 1, 1954

By A. W. Gauger

DESPITE many handicaps and in the face of many discouragements anthracite and bituminous coal producers continue to supply the needs of the nation now vastly multiplied by the demands of the greatest war of all time, total output being about 620,000,000 tons of bituminous and 64,445,000 of anthracite. The progress made by this industry during the national emergency reflects more credit on all connected therewith than will ever be given. Not only has the industry been called upon to produce more coal than ever before but it has also sent representatives to England to study and advise on methods for increasing production there, and has co-operated with other Allied Nations by welcoming engineers sent to this country to study American practice. One noteworthy development has been the growth of strip mining in the

Jan 1, 1945

By H. W. Gillett

MAINTENANCE of membership by the technical so¬cieties and the activity of these societies in spite of the adverse business situation have been noteworthy. This forcibly brings home the fact that industry recognizes that sound technical guidance is well worth its cost. The numerous difficulties and losses due to defects of various kinds arising from gas-metal reactions are now generally recognized and interest in these problems is widespread. The forthcoming A. I. M. E. round-table discussion of gas-metal problems will do much to clarify the situation and will permit us to assay our present knowledge and to suggest the proper direction for profitable future research. "The Age Hardening of Metal" was the title of the annual I. M. D. lecture delivered by Dr. Paul D. Merica. A critical review of the known facts relating to age-hardening phenomena was first given, followed by the presentation of a theory correlating the detailed observations which have been made regarding the mechanism of the hardening.

Jan 1, 1933

By G. G. Marino, J. W. Mahar

This paper provides an understanding of the behavior and potential damage of homes resulting from sag-type mine subsidence. This is done with extensive research of numerous case histories in Illinois collected by the authors. The house response to subsidence-induced ground displacements are summarized and evaluated. A damage level criteria, specifically developed for residential structures, is presented based primarily on repair costs. Damage levels and the associated subsidence profile characteristics for each case history are compared.

Jan 1, 1986

THE John Fritz Medal Board of Award, at its regu¬lar annual meeting Oct. 19, awarded its gold medal to Herbert Clark Hoover. Thus ended a process of selection begun a few years ago. The award was tentatively made a year ago by the Board, which is composed of sixteen recent past-presidents of the four national societies of Civil, Mining and Metallurgical, Mechanical, and Electrical Engineers, having together a membership of nearly 60,000. The sixteen members of the Board are: American Society of Civil Engineers : C. E. Grunsky, Robert Ridgway, George S. Davison and John F. Stevens ; American Institute of Mining and Metallurgical Engineers: William Kelly, J. V. W. Reynders, Samuel A. Taylor and E. DeGolyer; American Society of Mechanical Engineers: Fred R. Low, D. S. Jacobus, Dexter S. Kimball and Charles M. Schwab; American Institute of Electrical Engineers: Farley Osgood, M. I. Pupin, C. C. Chesney and Bancroft Gherardi.

Jan 1, 1928

By Henry G. Morris

The use of compressed air for the transmission of power has reached so great a development that we find numerous large establishments devoted to the manufacture of machinery for its production and application, and special periodicals published for the dissemination of information on the subject. Moreover, its employment is so general in mining operations that no apology is needed for the presentation to the Institute of such a paper as the present. The admirable articles of Mr. E. A. Rix, published in Conzpressed Air, show a wide range in the mechanical efficiency of air-compressors, varying, under different conditions, from 15 to 60 per cent.; and it is evident that any

Jan 1, 1902

By Milton T. Pana

Computer techniques now have been applied to the solution of a wide variety of scientific and engineering problems in the mining industry, but generally not in great depth in any one area. In mining, the area covered in greatest depth and with the greatest success has probably been mine planning and to a lesser degree production scheduling. A rather comprehensive review of the literature related to mine planning and production scheduling indicates that contributions in these areas have been geographically, as well as organizationally, widespread. Of twenty-six papers reviewed, eleven were from industry, eight from educational institutions, four from computer vendors, two from the Bureau of Mines, and one from a private consultant. The conclusions that can be derived from the literature are: First, the-state-of-the art has advanced to the point that computing ore reserves and developing mining plans with the aid of the computer is now a routine practice; second, the application of the computer to mine planning problems has markedly improved our ability to estimate ore reserves, more accurately define pit limits, and determine an optimum mining sequence. MINE PLANNING The papers in this section deal essentially with the problem of determining the final pit limits of an orebody and the ore reserves associated with a given pit limit. The problem is probably best described by Soderberg25 and more recently by Reibell. 23. There are two techniques currently being applied to this problem by several mining companies: 1) the multiple-cone technique and 2) the Lerch-Grossman algorithm. The multiple-cone technique is the older of the two techniques and has the advantage of being more flexible, allowing an engineer to easily vary pit slopes in different sectors of the design. The technique can also be used to define intermediate pit contours. The Lerch-Grossman algorithm is appealing in that the final solution is given in the form of a true mathematical optimum. The technique is limited, however, in that the size of the blocks in the orebody model are a function of the desired

Jan 1, 1969

By Norman Braly

THE following is not offered as an extended paper on the subject of shaft sinking, but more as a description of the present practice of shaft sinking in the Butte district. The Anaconda company is sinking at present the following shafts: Badger State, Moose, Mountain Consolidated, Mountain View, Pennsyl-ania and Tropic. At the High Ore and Leonard mines the shafts are being deepened by sinking two compartments and will subsequently be enlarged to the full working size by raising alongside the compartments which are now being sunk. The following other companies are also sinking shafts: Butte-Alex Scott, Butte and Zenith City, Boston and Corbin, North Butte Mining Co. (at the Granite Mountain shaft), East Butte Co. (at the Pittsmont shaft), and the Rainbow Lode Development Co. Shaft Timbering. The shafts of the Butte district, generally speaking, are of three compartments arranged in a straight line, and the pump compartment is usually arranged for the use of an auxiliary hoisting cage, as well as for carrying pipe lines and electric wires. The Rainbow shaft is practically square, and of three compartments. The length of the shafts outside of timber will vary from 17 to 22 ft., and the width from 6 ft. 6 in. to 7 ft. Fir timber is used in all shaft work. This may be obtained from the Coast, when it is known as Coast fir, or from Idaho or Montana, when it is known as native fir. The native fir seems to be the tougher wood, but it is hard to obtain clear lumber in the lengths and sizes necessary for shaft work. Some of the shaft timber of the Anaconda company has been treated with creosote as a preservative, but this practice has not come into general use, as the ground of the camp is so heavy that the timbers usually crush before they rot. The size of timber most .used for shaft work is 12 by 12 in., while 10 by 12 in., 10 by 14 in. and 12 by 14 in. are used for some of the special pieces around the shaft. The new Leonard shaft is timbered with 14 by 14 in. wall plates throughout.

Jan 8, 1913

Pumping coal to market may help Appalachian coal operators increase their share of the eastern seaboard fuel business. Transporting it by pipeline is already an accomplished fact, but until recently it had to be dewatered to be used in boiler furnaces. The campaign for these eastern markets was begun in earnest last November by the widely publicized announcement of successful plant-scale firing of a central station boiler with coal slurry pumped to the burners. This latest advance makes coal similar to oil and gas in convenience in handling and controlling at the consumption end of the pipeline. Slurry could be considered a new commodity for the fuel market. HUGE POTENTIAL MARKET The heaviest concentration of power plants in the U.S. is along the line Washington, Baltimore, Philadelphia, New York and Boston which makes this region the best hunting ground for selling pipelined coal brought from western Pennsylvania and northern West Virginia. Furthermore, if this region is assumed to consume 125 million tons of coal annually, on a comparable basis, the consumption of oil and gas would be about 180 million tons. Even if all of this fuel is not consumed in central stations, it is still a very big market for coal at the right price. Consolidation Coal Co. and Texas Eastern Transmission Co. are trying to line up customers in this area so that a pipeline can be built. This is not to say that there are not many other areas in the U.S. that could not be supplied advantageously by a mine-to-market pipeline.

Jan 1, 1962

By AIME

AS with Phil Kraft, referred to on this page last month, travel has always held a great fascination for Raymond Frank Baker and for that reason he determined to become a geologist. He had heard that geologists travel and that was what he wanted to do. Now as chief geologist for The Texas Co. his early wish has been fulfilled-he spends almost one third of his time journeying' from one oil field to another. Mr. Baker was born in New Haven, Conn., on Jan. 11, 1892, and went through the public schools in New Britain. A stalwart New Englander, he attended Yale and in 1912 received a degree in civil engineering. For a year following this he worked as a civil engineer for the New York Central Railroad, but his early urge to travel widely could not be satisfied here. So in 1913 he re-entered Yale and until 1916 studied mining and economic geology. He had a little taste of field work, which later became so enjoyable to him, in the summer of 1915 when he worked with the U. S. Geological Survey as a geologic aid. In 1916 he made his first contact with The Texas Co. when he entered their Tulsa office as a geologist. This early career was interrupted by service in the

Jan 1, 1947

By Francis Crockard

DURING the past five years we have probably witnessed greater technological advances than in any similar period. Industry and science have steadily marched ahead. The makers of iron and steel products have watched with great interest the development of stream-lined trains, faster and safer airplanes, the entirely new science of air-conditioning and the widespread use of stainless steels. Since 1930, we have witnessed the erection of the world's largest suspension bridge, the largest and fastest ocean liner and the spectacular Boulder Dam, while even greater things are planned in these particular fields. Other indus-tries, too, have been moving ahead rapidly. This advance in a few years has been caused primarily by the fierce competition of the depression. Now, more than ever, is the emphasis placed upon quality and service. Makers of southern merchant pig iron have been no exception and have been confronted with increasingly strict chemical specifications and with much greater stress on physical characteristics than ever before. For example, sulfur in the iron must be held very low, competition demanding that it be in the 0.020's and low 0.030's; silicon content must be held within a very narrow range, and definite requirements of phos-phorus and manganese are an essential part of the specifications. Physical characteristics are becoming of increasingly greater impor-tance. The introduction of triple-skimmed, slow-cooled iron several years ago was the first step in this direction. Now there are a few customers who buy iron by chemical analysis and physical appear-ance, having found that the analysis alone is an insufficient guide to their requirements.

Jan 1, 1935

By Franz Posepny

CONTENTS. Introduction. Part I. General Facts And Theories. [ ]

Jan 1, 1902

ANDERSON, ALEXANDER, Captain, Royal Garrison Artillery. ANDERSON, GEORGE K., JR., Lieutenant, 30th Co., 3d Replacement Regiment. ARMSTEAD, H. H., Captain, Quartermaster Corps, U. S. N. A. ARMSTRONG, HAROLD KERR, Student Flight Officer, U. S. Naval Reserve Flying Corps, Dunwoody Naval Training Station, Minneapolis, Minn. BAKER, HARRY A., Captain, Co. M, 53d Pioneer Infantry. BASSETT, THOMAS E., Corporal, 340th. Field Artillery, Battery A, 89th Division, A. E. F. BATES, Wm.. T., 3d Reserve Officers' Training Camp. BAUMMGARTEN, K., 1st Lieutenant, 1st Corps School A. P. 0. 703. BAYLESS, G. E. S., Supply Dept., U. S. Submarine Base, New London, Conn. BENSEL, J. A., Major, U. S. R., Board of Control, War. Construction Activities, Norfolk, Va. BILLICK, DON C., Co. C, Ordnance. Supply School. BILLINGSLEY, PAUL, 1st Lieutenant, National Army, Statistics Branch,. General Staff. BLANDY, S. H. B., B. E. F.

Jan 8, 1918

By Arthur S. Dwight

From the latest and best literature on lead-smelting, little can be learned concerning the present state of the art of mechanical feeding in the United States. H. O. Hofman, in his Metallurgy of Lead (5th ed., 1899), briefly describes the main features of the system in use at Pueblo, Colo., and later (p. 235) says " the only successful mechanical feeding, as far as the writer is aware, is that found at the works of the Pueblo Smelting and Refining Co." H. F. Collins, in his Metallurgy of Lead and Silver (London, 1899), covers American practice pretty thoroughly; but as to mechanical charging, he says: "The German plan of taking off the gases by means of a small iron pipe suspended in the center, and the plan of charging by means of cup and cone, as in iron blast-furnaces, have both been tried, but have not found favor, chiefly on account of the difficulty of obtaining free access to the furnace-shaft for barring, etc., with such devices."' . H. W. Hixon, in his Notes on Lead and Copper Smelting (3d ed., New York, 1900), gives a description and drawing of the Hixon feeding device, as originally installed at East Helena. Evidence that this system of feeding has passed its experimental stage, and deserves more serious consideration than it has heretofore received, is furnished by two large plants—the Pueblo and the East Helena—of the American Smelting and Refining Co., where mechanical feeding has been in continuous and successful operation for a considerable period; one new plant now erecting at Salt Lake City, Utah, and one old one belonging to the same company, the El Paso works, now being rebuilt after a disastrous fire, in both of which mechanical feeding is to be a prominent feature ; one new plant of an independent concern at Torreon, Mexico, which will adopt mechanical feeding; and a number of other smaller plants, among

Jan 1, 1902

By Robert M. Weidenhammer

For years before the war, Coal had the reputation of being a sick industry. Currently it is operating at peak production and succeeding pretty well in keeping out of the red. But, says Mr. Weidenhammer, it will have a relapse as soon as the war ends unless (1) working capital can be built up; (2) it gets the support of the people and Congress; and (3) a truly long-range national fuel policy is formulated.

Jan 1, 1943

The following is an incomplete list of members and guests who called at Institute headquarters during the period June 10, 1918 to July 10, 1918. F. C. Alsdorf, Tucson, Ariz. Emory M. Marshall, Camp Raritan, N. J. Juan F. Brandes, Santa Barbara, Cal. Jacques S. Negru, Camp Niagara, Ont. .H. Smith Clark, Kansas City, Mo. Arvid E. Nissen, High Bridge, N. J. J. S. Cunningham, Charleston, W. Va. Richard G. Place, So. Strafford, Vt. W. G. Eberhardt, Tucson, Ariz. Frank H. Probert, Berkeley, Cal. M. Eldredge, Bombay,. India. Martin A. Roudabush, Osterburg, Pa. A. D. R. Galloway, Accra, W. Africa;. P. H. Royster, Minneapolis, Minn. F. Hanst, Harrisburg, Pa. J. L. Schueler, Peoria, Ill. B. B. Hood, Chrome, N.. J. Henry B. Smith, New Britain, Conn. Paul S. King, Wilmington, Del. W. G. Sommer, Peoria, Ill. E. D. Kinney, Anaconda, Mont. A. L. Toenges, Roanoke, Va. E. W. Kohl, Jr., Philadelphia, Pa. G. D. B. Turner, Butte, Mont. James W. Love, Knoxville, Tenn. A. T. Ward, Bellefonte, Pa. Edwin A. Austin, formerly with the Yukon Gold Co., is superintendent of the Elkoro mine at Jarbidge, Nev. John W. Beard is now with the Cia Minera de Penoles, Ojuela, Dgo., Mexico, via Mapimi. R. S. Bonsib has accepted a position with the United States Emergency Fleet Corporation as District Safety Engineer, San Francisco, Cal. Albert Burch has been appointed by the Bureau of Mines to encourage the mining of chrome. F. B. Caldwell is working for the U. S. Bureau of Mines, under Albert Burch, in the investigation of chromite deposits. W. A. Carlyle has taken over the duties (in addition to his own) formerly assigned to E. P. Mathewson with the British America Nickel Corporation, at Sudbury, Canada. R. M. Catlin received the honorary degree of Doctor of Science at the recent commencement of Rutgers College, New Brunswick, N. J. S. K. Dahl is giving up his position as mill superintendent with the Messina Mines, which have been suspended, and is returning to this country. Algernon Del Mar has become manager of the Techatticup mines, El Dorado Canyon, Nev. Robert Dye has succeeded D. L. Forbes as manager of the Teck-Hughes at Kirkland Lake, Ont., Canada. J. O. Elton, superintendent of the Anaconda company's electrolytic zinc plant at Great Falls, Mont., is doing special work with the U. S. Bureau of Mines. R. B. Caples takes charge of the plant in his absence. George H. Gibbs has resigned his position as engineer at Messrs. T. & 1. Bradley & Sons, Ltd., Darlaston blast furnaces, Darlaston, and is now located at "Belmont." Litchfield Road, Rushall, Walsall, England. William D. Gordon, for the past 7 years manager of The Mine & Smelter Supply Co. at El Paso, has been elected president of Camphuis, Rives & Gordon,. Inc., and has opened American headquarters for the company at 81 New Street, New York, N. Y. E. Harms, for the past 16 years inn charge of metallurgical operations of the Torreon, Mexico; lead and copper smelter, has resigned and is now located at El Paso, Tex.

Jan 8, 1918

By Herbert Clark Hoover, Lou Henry Hoover

PREVIOUSLY I have dealt with the methods of separating silver from copper. There now remains the portion which treats of solidified juices ; and whereas they might be considered as alien to things metallic, nevertheless, the reasons why they should not be separated from it I have explained in the second book. Solidified juices are either prepared from waters in which nature or art has infused them, or they are produced from the liquid juices themselves, or from stony minerals. Sagacious people, at first observing the waters of some lakes to be naturally full of juices which thickened on being dried up by the heat of the sun and thus became solidified juices, drew such waters into other places, or diverted them into low-lying places adjoining hills, so that the heat of the sun should likewise cause them to condense. Subsequently, because they observed that in this wise the solidified juices could be made only in summer, and then not in all countries, but only in hot and temperate regions in which it seldom rains in summer, they boiled them in vessels over a fire until they began to thicken. In this manner, at all times of the year, in all regions, even the coldest, solidified juices could be obtained from solutions of such juices, whether made by nature or by art. Afterward, when they saw juices drip from some roasted stones, they cooked these in pots in order to obtain solidified juices in this wise also. It is worth the trouble to learn the pro- portions and the methods by which these are made. I will therefore began with salt, which is made from water either salty by nature, or by the labour of man, or else from a solution of salt, or from lye, likewise salty. Water which is salty by nature, is condensed and converted into salt in salt-pits by the heat of the sun, or else by the heat of a fire in pans or pts or trenches. That which is made salty by art, is also condensed by fire and changed into salt. There should be as many salt-pits dug as the circumstance of the place permits, but there should not be more made than can be used, although we ought to make as much salt as we can sell. The depth of salt-pits should be moderate, and the bottom should be level, so that all the water is evaporated from the salt by the heat of the sun. The salt-pits should first be encrusted with salt, so that they may not suck up the water. The method of pouring or leading sea-water into salt-pits is very old, and is still in use in many places. The method is not less old, but less common, to pour well-water into salt-pits, as was done in Babylon, for which Pliny is the authority, and in Cappadocia, where they used not only well-water, but also spring-water. In all hot countries salt-water and lake-water are conducted, poured or carried into salt-pits, and, being dried by the heat of the sun, are converted into

Jan 1, 1950

By L. Weaver

THE Tennessee Copper Co.'s mines are in the southeast corner of the state of Tennessee, Polk Co., in the well-known Ducktown copper basin. Their new circular production shaft will eventually be the only ore hoisting shaft, and is located for handling ore from Boyd, Calloway, Mary, and Cherokee mines. A circular, rather than a rectangular, shaft was decided upon because: 1-The circular shaft section is stronger when lined with concrete. Reinforcing steel was not required, thus reducing lining cost by one- quarter. 2-Water sealing was desired; it was thought it could best be done with a concrete lining followed by pressure grouting to eliminate water seeps. 3-The shaft labor saving equipment could best be used in a large opening, so the round section was made for economy, sinking, mucking, concreting and water sealing. Less shaft steel is used than could have been possible with steel sets. There are no posts required; center beams and Tee plate assembly placed at 10 ft hold the 100 lb steel guide rails.

Jan 1, 1950

By S. M. Marshall, B. M. Bird

For a number of years European investigators have used laboratory methods of predicting the probable strength of coke made from coal, and recently several investigators in the United States have reported the use of various tests for this purpose. There is at present no method accepted as standard, however, nor is there even agreement as to the general type of test that should be used. Furthermore, because the details of most of the tests have not been worked out carefully, one investigator can not hope to duplicate the work of another. The extension of coke manufacture to new localities in the United States, and the increasing need for cokes of exceptional qualities made from the most economical mixtures, made it desirable to have some simple laboratory test which will determine whether given coals, alone or blended with other coals, are more satisfactory from the standpoint of coke strenpth- than others of different cost. The work described herein has resulted in the development of a simple laboratory test which, it is believed, can be generally adopted in coal laborat,ories, and which will give concordant results even though performed by different investigators in different laboratories. The general method of predicting whether a coal or a mixture of coals will produce a strong coke, resistant to crushing and shattering, has been to correlate the known strengths of the cokes produced in commercial ovens with some measurable constituent or with some property of the coals, and then to use the relationship so found for forming an estimate of the coking strengths of coals unknown. Several such correlations have utilized the percentages of the various ultimate constituents of coal, such as the oxygen content and the hydrogen-oxygen ratio;(39)§ other correlations have involved the proportion of a, B and r com-pounds, (17,21,30c) or of "oil and solid bitumens."(16,30) Also a relationship has been traced between the coking properties of coal and the rate of change of the resistance offered to the flow of an inert gas by fine particles of the coal while being slowly heated. (11,176) But the most general corre-

Jan 1, 1930