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By Orr Hamilton

VALUATION of a mine is an approximation of its true cash value which requires the application of fundamental principles of economics. Mines are valued from necessity, for the following reasons: (a) Transfers of titles. (b) Dissolutions of partnerships or corporations. (c) Mergers of mining companies. (d) Appraisals for the purpose of State and Federal taxation. (e) Establishment of the fact of worth as a basis of loans. (f) Determination of values as frequently required in litigation. (g) Listing of stock for sale by a reputable stock exchange. For the majority of purposes a valuation is required as at the present time, but for some purposes valuations as of bygone times may more nearly reflect the intrinsic worth of a mine because its subsequent history can never be, entirely ignored, but valuations made as at the present time are better indicators of cash values. Many mines with great intrinsic worth have been sold for small cash prices. The object of legitimate mine valuations is to deter-mine salable value, or that price in cash at which a transfer of the property from a willing seller to a willing buyer might be consummated, assuming that both vendor and vendee have knowledge of all pertinent data and that the owner, is not forced to sell at a sacri-fice-the definitions of fair market value precluding a forced sale.

Jan 11, 1923

By Lawrence Addicks

Discussion of the paper of LAWRENCE ADDICKS, presented at the San Francisco meeting, September, 1915, and printed in Bulletin No. 104, August, 1915, pp. 1471 to 1484. L. D. RICKETTS, New York, N. Y.--In the Southwest we have stored up millions of tons of tailings in which the copper exists partly as sulphide and partly in an oxidized condition. Mr. Addicks' first paper suggests a, likely process for the treatment of such material. His second paper 1 deals with the recovery of copper from clear solutions of notable strength, and such solutions may come from the sulphating roast or direct from the leaching of completely oxidized copper ores of which vast deposits are known to exist. What strikes me particularly about the latter paper is the keen perception shown and the clear manner in which the writer has attacked the fundamental principles of the process. He calls your attention to the fact that ferrous sulphate is necessary in the electrolyte and is an ideal depolarizer; that sulphurous acid must be, used to reduce the ferric sulphate produced and thus prevent re-solution of copper at the cathode; that mechanical agitation in the cell, in order to bring the ferrous sulphate in contact with the anode and the copper in contact with the cathode, is essential to efficient work; that lead anodes are

Jan 12, 1915

By Charles F. Herbert

In February of this year at the Washington, D.C., hearings of the Interior Department on the Alaska pipeline, the author was amazed to hear speaker after speaker oppose not only pipline construction but any development whatsoever in the State of Alaska. In one case, a man objected to development in Alaska because his neighbor in Maryland had cut down some shade trees. Another man recited at length from the poems of Robert W. Service. While it seemed inconceivable that such thoughtless opposition should have any effect, a check with the offices of some congressmen showed that mail was largely against any development of Alaska. In the barrage of words and redundant phrases directed against Alaska, it is difficult to find a thought worthy of study. Fortunately, there is a statutory guide towards resolution of the problem of development versus non- development. This law, the Environ- mental Protection Act of 1969, has indeed given much of industry the jitters; copper smelters see no way to comply with the new sulfur- emission standards, the Alaska Department of Highways estimates that the Act has nearly doubled the cost of planning and engineering for highway construction. In spite of these and many other troubles and costs, the Act provides a sound legal basis for defeating nihilistic emotions and, since Alaska is relatively undeveloped, adoption of environmental safeguards will be simpler than correcting longstanding abuses.

Jan 1, 1971

The regular meeting of the Trustees of United Engineering Society was called to order at 4 P. M. Thursday, Feb. 27, 1919, in the Board Room of the American Society of Civil Engineers, Engineering Societies' Building, New York. Minutes of a joint meeting of the Finance Committee of United Engineering Society with finance committees of Founder Societies on Feb. 14, were presented. The President called attention to actions relating to the recataloging of the Library and the support of Engineering Societies Employment Bureau of Engineering Council. The activity of the Employment Bureau was approved and support by the Societies informally assured. In response to a communication from the Fifth Avenue Association, the Secretary was instructed to write favoring the continuance of the daylight saving law. As to recataloging of Engineering Societies Library, it was announced that the Mining, Mechanical, and Electrical Engineers had voted appropriations, as requested, and the action of the Civil Engineers was awaited. A list of applications for offices in Engineering Societies' Building, revised to Feb. 27, was read, showing requests for a total of 29 rooms. The President stated that a decision must be reached soon as to what reply shall he made to these applications. Charles F. Scott, one of the original trustees, who was present, remarked upon the growth of United Engineering Society and his satisfaction at its success. ALFRED D. FLINN, Secretary.

Jan 4, 1919

Iron Ore Resources of the World (Die Eisenersvorrate der Welt)_ By G. Einicke. Verlag Stahleisen, Dusseldorf, 1950. 418 p., with 192 tables and an atlas volume containing 100 p. of reaps. 66 German Marks.-A notable work in which the latest available information on iron ore deposits has been compiled by diligent work, continent by continent, country by country. The author reveals the effect of geological formations, iron content of ore, accessability, cost of transportation, political and economic considerations. Ore beds of importance to the German iron and steel industry are given more space than others. The bibliography contains almost 250 references. A tragic comic feature is the author's complaint that as soon as a map of iron ore resources of a country has been completed, the country's boundaries are changed. Reviewed by W. Trinks, Carnegie Institute of Technology. Industrial Research Laboratories of the United States. National Research Council, Washington, D. C. Ninth Edition. 1950. 445 p. $5.-Contains information on the research laboratories of 2845 industrial and commercial organizations, including names of research executives, location of labs, types of activity, whether any consulting services are offered. There are two appendices, one of which lists data on government labo ratories which cooperate with industry, and the :)ibex naming universities and colleges offering research services to industry.

Jan 2, 1951

By Bruce A. Kennedy

This is an opportune time to examine the disposition of practical rock mechanics in the mining industry. The rock mechanics world has put on steam with publication of a number of books and the organization of a large number of symposia and teaching seminars. SME has just published Stability ill Open Pit Mining. proceedings of a conference held In November 1970 in Vancouver, R.C. R book entitled Planning Open Pit Mines covering the entire range of open pit mining with emphasis on slope stability has just been published by the South African Institute of Mining and Metallurgy. The Thirteenth Symposium on Rock Mechanics was held at the University of Illinois. Urbana-Champaign, during the last week of August. The University of British Columbia's Division of Continuing Education is holding a symposium and specialty seminars on stability in open pit mining during the first week in November. A tremendous planning effort has started to organize the Tl3ii.d Congress of the International Society of Rock Mechanics in Denver in 1974. This meeting is held every four years in the country of origin of the president of the Society. This third congress comes to the U.S.A. with Leonard Obert of the 17. S Bureau of Mines as president of the Society. The previous two were held in Lisbon. Portugal and Belgrade. Yugoslavia.

Jan 1, 1971

By Charles H. Fulton

FOR some time it has been thought that there should be > closer relationship between the members' of the Institute engaged in education in the mining schools, the mining, metallurgical, ceramic, and geological departments of universities, and the members of the Institute actually engaged in the production of mineral products and the operation and direction of works. The American Society of Chemical Engineers and the American Ceramic Society have for some years past devoted especial attention to the educational matters of their respective fields. The Engineering Foundation, representing the great engineering societies of the country, is deeply interested in technical education and maintains a Committee on Educational Research.

Jan 1, 1932

A special meeting of the Alaska Mining and Engineering society, held at Perseverance Mine of the Alaska Gastineau Mining Co. on Mar. 17, 1017, was attended by 46 members and about 80 guests, among whom were members of the Alaska Territorial Legislature. After an interesting trip through the mine in the afternoon, the members and guests assembled for dinner at the Perseverance Dining Room. After the dinner G. T. Jackson, assistant manager of the company, as president of the society, called the meeting to order. After the reading of the minutes, he welcomed the guests and then gave a short history of Perseverance Mine. B. L. Thane, manager of the company, briefly out-lined its general organization. The following papers were read-by members of the society and members of the staff of the Perseverance Mine: "The Organization of the Mine Staff and the Methods of Mining," by B. B. Nieding, Mine Supt.; "Tramming Equipment and Costs," by R. R. Van Valkenburgh; "The Surveying of the Mine," by R. L. Healey, Mine Engineer; "The Electrical Equipment of the Mine," by W. S. Pullen, Supt., of Power Supply; "The System of Mine Accounting, "by E. J. Doherty, Mine Accountant; and "The Mine Buildings," by D: J. Argall, Asst: Mine Supt. M. T. Tolch, Transportation Supt., described briefly the general transportation of the ore to the mill and the equipment used.

Jan 6, 1917

By E. F. Reed

CONSIDERABLE deep hole prospect drilling has been done in the last few years in the Globe-Miami mining district about 70 miles east of Phoenix, Arizona, and in the San Manuel-Tiger area about 50 miles south of the Globe-Miami region. More than 205,000 ft of churn drilling have been completed by the San Manuel Copper Corp. at their property in the Old Hat Mining District in southern Pinal County. The deepest hole on this property is 2850 ft; there are 49 holes deeper than 2000 ft. At the adjoining Houghton property of the Anaconda Copper Mining Co., where only one hole reached 2000-ft depth, there were 27,472 ft of churn drilling and 3436 ft of diamond drilling. Three churn drill holes were deepened by diamond drilling methods. Near Miami in the Globe-Miami district the Amico Mining Corp. drilled four holes by combined churn and rotary drilling methods, the total amounting to 13,879 ft, of which 2256 ft were drilled with a portable rotary rig. In the same district, besides doing a large amount of shallow prospect drilling, the Miami Copper Co. drilled two holes of 2560 and 3787 ft, respectively, which were completed by churn drilling methods. The rocks encountered in drilling at San Manuel and Tiger are described by Steele and Rubly in their paper on the San Manuel Prospect' and by Chapman in a report on the San Manuel Copper Deposit.' The rocks are well-consolidated Gila conglomerate, quartz monzonite, and monzonite porphyry. In some places these formations stand very well while being drilled, and three holes were drilled without casing, the deepest of which was 2200 ft. In other holes faulted and fractured ground made drilling difficult. In the Globe-Miami district the deep drilling was done in the down-faulted block of Gila conglomerate east of the Miami fault and in the underlying Pinal schist. The geology of this area is described by Rannome. In the Amico holes the conglomerate varied from material consisting entirely of granite boulders and fragments to a rock made up of schist fragments in a sandy matrix; in the Miami Copper Co. holes there were more granite boulders and the material was poorly consolidated. Drilling was much more difficult and expensive in the Miami area than in the San Manuel district, mainly because of the depth of the holes and the formations drilled. All the deep hole prospecting described in this paper was done with portable rigs. The churn drill rigs were of several types, of which the Bucyrus-Erie were the most popular. Bucyrus-Erie 28L, 29W, and 36L rigs were used on some of the deeper holes on the San Manuel property. A few Fort Worth spudder types were tried, and the deepest hole at San Manuel was drilled with a Fort Worth Jumbo H. The spudder type is considerably larger than most other rigs used on this work and required a larger location site. The spudders were belt-driven machines with separate power units, and time required for setting up and moving was much longer than with the more portable drills. All the churn drilling was done by contractors or with machinery leased from them. A few of the contractors had complete equipment, including most of the necessary fishing tools. Unusual and special fishing tools were obtainable from the supply companies in the oil fields of New Mexico or in the Los Angeles area. Most of the contractors used equipment with standard API tool joints, so that much of it was interchangeable. Failure of tool joints is one of the principal causes of fishing jobs. It can be minimized if the joints are kept to the API specifications and the proper sized joints are used in the various holes. The minimum sizes that should be used with various bits are as follows: 12-in. and larger bits, 4x5-in. tool joints; 10-in. bits, 31/4x41/4-in. tool joints; 8-in. bits, 23/4x 33/4-in. tool joints; 6-in. bits, 2Y4x3Y4-in. tool joints; 4-in. bits, 15/ix25/8-in. tool joints. Two rotary drill rigs were tried at San Manuel on the same hole, and a portable rotary drill rig was used on the Amico drilling for test coring the formation and for drilling in holes 3 and 4. Rotary drilling differs from churn drilling or cable tool drilling in that the bit is revolved by a string of drill pipe and the cuttings are removed from the hole by a thin solution of mud pumped through the drill pipe. The principal parts of a rotary rig are the power unit, a rotating table to revolve the drill pipe, hoists to raise and lower the pipe and to handle casing, and a pumping system to circulate the drilling liquid. The rig used on the Amico property at Miami was mounted on a truck. The larger rig used on the San Manuel property was hauled by several trucks and had separate turntable and pumping units. Diamond drill coring equipment was used successfully with the rotary rig in the holes on the Amico property. To allow for 23/8-in. drill pipe with tool joints, 31h-in. core barrels and bits were used. With the standard 31h-in. core barrel there was considerable difficulty in maintaining circulation with mud, so a barrel was designed with a smaller inner tube and a broad-faced bit. This allowed coarser material to circulate between the barrels. Rock bits of 55/8 to 3 in. were used with the rotary rig for drilling between core runs. Diamond drill equipment is much lighter than churn drill tools, so that fishing tools can usually be obtained from supply houses by air express when needed. Three churn drill holes on the Houghton property at Tiger were deepened by diamond drilling with Longyear UG Straitline gasoline-driven machines. The open churn drill hole was cased with 21h-in. black pipe. In deep hole churn drilling, casing is one of the most important items, especially in drilling in un-consolidated material like the formations drilled by

Jan 1, 1953

By E. F. Reed

CONSIDERABLE deep hole prospect drilling has been done in the last few years in the Globe-Miami mining district about 70 miles east of Phoenix, Arizona, and in the San Manuel-Tiger area about 50 miles south of the Globe-Miami region. More than 205,000 ft of churn drilling have been completed by the San Manuel Copper Corp. at their property in the Old Hat Mining District in southern Pinal County. The deepest hole on this property is 2850 ft; there are 49 holes deeper than 2000 ft. At the adjoining Houghton property of the Anaconda Copper Mining Co., where only one hole reached 2000-ft depth, there were 27,472 ft of churn drilling and 3436 ft of diamond drilling. Three churn drill holes were deepened by diamond drilling methods. Near Miami in the Globe-Miami district the Amico Mining Corp. drilled four holes by combined churn and rotary drilling methods, the total amounting to 13,879 ft, of which 2256 ft were drilled with a portable rotary rig. In the same district, besides doing a large amount of shallow prospect drilling, the Miami Copper Co. drilled two holes of 2560 and 3787 ft, respectively, which were completed by churn drilling methods. The rocks encountered in drilling at San Manuel and Tiger are described by Steele and Rubly in their paper on the San Manuel Prospect' and by Chapman in a report on the San Manuel Copper Deposit.' The rocks are well-consolidated Gila conglomerate, quartz monzonite, and monzonite porphyry. In some places these formations stand very well while being drilled, and three holes were drilled without casing, the deepest of which was 2200 ft. In other holes faulted and fractured ground made drilling difficult. In the Globe-Miami district the deep drilling was done in the down-faulted block of Gila conglomerate east of the Miami fault and in the underlying Pinal schist. The geology of this area is described by Rannome. In the Amico holes the conglomerate varied from material consisting entirely of granite boulders and fragments to a rock made up of schist fragments in a sandy matrix; in the Miami Copper Co. holes there were more granite boulders and the material was poorly consolidated. Drilling was much more difficult and expensive in the Miami area than in the San Manuel district, mainly because of the depth of the holes and the formations drilled. All the deep hole prospecting described in this paper was done with portable rigs. The churn drill rigs were of several types, of which the Bucyrus-Erie were the most popular. Bucyrus-Erie 28L, 29W, and 36L rigs were used on some of the deeper holes on the San Manuel property. A few Fort Worth spudder types were tried, and the deepest hole at San Manuel was drilled with a Fort Worth Jumbo H. The spudder type is considerably larger than most other rigs used on this work and required a larger location site. The spudders were belt-driven machines with separate power units, and time required for setting up and moving was much longer than with the more portable drills. All the churn drilling was done by contractors or with machinery leased from them. A few of the contractors had complete equipment, including most of the necessary fishing tools. Unusual and special fishing tools were obtainable from the supply companies in the oil fields of New Mexico or in the Los Angeles area. Most of the contractors used equipment with standard API tool joints, so that much of it was interchangeable. Failure of tool joints is one of the principal causes of fishing jobs. It can be minimized if the joints are kept to the API specifications and the proper sized joints are used in the various holes. The minimum sizes that should be used with various bits are as follows: 12-in. and larger bits, 4x5-in. tool joints; 10-in. bits, 31/4x41/4-in. tool joints; 8-in. bits, 23/4x 33/4-in. tool joints; 6-in. bits, 2Y4x3Y4-in. tool joints; 4-in. bits, 15/ix25/8-in. tool joints. Two rotary drill rigs were tried at San Manuel on the same hole, and a portable rotary drill rig was used on the Amico drilling for test coring the formation and for drilling in holes 3 and 4. Rotary drilling differs from churn drilling or cable tool drilling in that the bit is revolved by a string of drill pipe and the cuttings are removed from the hole by a thin solution of mud pumped through the drill pipe. The principal parts of a rotary rig are the power unit, a rotating table to revolve the drill pipe, hoists to raise and lower the pipe and to handle casing, and a pumping system to circulate the drilling liquid. The rig used on the Amico property at Miami was mounted on a truck. The larger rig used on the San Manuel property was hauled by several trucks and had separate turntable and pumping units. Diamond drill coring equipment was used successfully with the rotary rig in the holes on the Amico property. To allow for 23/8-in. drill pipe with tool joints, 31h-in. core barrels and bits were used. With the standard 31h-in. core barrel there was considerable difficulty in maintaining circulation with mud, so a barrel was designed with a smaller inner tube and a broad-faced bit. This allowed coarser material to circulate between the barrels. Rock bits of 55/8 to 3 in. were used with the rotary rig for drilling between core runs. Diamond drill equipment is much lighter than churn drill tools, so that fishing tools can usually be obtained from supply houses by air express when needed. Three churn drill holes on the Houghton property at Tiger were deepened by diamond drilling with Longyear UG Straitline gasoline-driven machines. The open churn drill hole was cased with 21h-in. black pipe. In deep hole churn drilling, casing is one of the most important items, especially in drilling in un-consolidated material like the formations drilled by

Jan 1, 1953

By AIME AIME

EVER since his college days at the University of Iowa, the professional interest of Morris Morgan Leighton has centered on geology, and he now heads the State Geological Survey of Illinois. Just 52 years ago--on Aug. 4, 1887-he was born at Wellman, Iowa. He remained at the State university for his Master's degree, awarded in 1913. A two-year fellowship at the University of Chicago led to a Ph. D. degree, after which Dr. Leighton went out to Seattle as instructor in geology at the University of Washington during 1915-'16. He returned to Iowa as assistant professor of geology at Iowa State Teachers' College for a year, followed by another year at Seattle, after which he returned permanently to the Middle West, first as acting professor of geology at Ohio State and then, from 1919 to 1923, as assistant professor of geology at the University of Illinois and geologist for the Illinois Geological Survey. Of the latter organization he has been chief since 1923, with no present teaching duties. As a result of the successful work of the Survey, notably in non-metallics and in the initiation and stimulation of the recent oil activities in the southern part of the State, it is soon to have a new building with modern laboratory facilities.

Jan 1, 1939

TO metallurgists generally, Arthur S. Dwight is no stranger even to those who do not know him personally. He is one of those contributors to technical progress whose names will go down to posterity because of their being attached to a successful machine or process, such as Dorr, Hardinge, or Marcy, or Wedge, MacDougall, or Herreshoff. The roasting and sintering method and equipment developed by Colonel Dwight and his associate, the late Richard L. Lloyd, may be found in lead smelters throughout the world, and also in many metallurgical works dealing with other ores, including those of iron. It is ordinarily used to desulphurize and agglomerate fine ores for subsequent smelting. Colonel Dwight's citation as James Douglas Medalist reads: "For his contributions to the art of smelting nonferrous ores; and particularly for his pioneer work in developing equipment and technique for sintering such ores and metallurgical products." The medal was awarded at the last Annual Meeting of the A.I.M.E. but unfortunately the medalist was unable to leave Florida at the time to receive it in person.

Jan 1, 1942

By R. K. Datta, T. S. Davis

YVO4:EU, excited under 3650A radiation, shows a marked increase in total brightness with in~rease in temperature. At 25°C the response to 3650A radiation is about 48 pct of its maximum response which occurs at about 350°C, Fig. 1. In an attempt to explain the phenomenon, one of the present authors' (R.K.D.) investigated the diffuse reflectance spectra of the phosphor at different temperatures (up to -150°C) and was unable to observe any significant change to which the increased brightness could be reasonably ascribed. Since then diffuse reflectance spectra at elevated temperatures have been obtained in this laboratory using an improved device. A significant decrease in the diffuse reflectance of a phosphor in the ultraviolet region—especially in the longer wavelength region—at -300°C has been observed. The purpose of this note is to describe the device used for high-temperature reflectance measurements and to explain the increased brightness of YVO4:Eu phosphor at elevated temperatures under 3650A excitation. Experimental. YVO4 and YVO4:Eu samples were prepared as previously described.' The elevated-temperature reflectance spectra were obtained with a Cary 14 spectrophotometer equipped with a diffuse reflectance accessory and a ring collector. CaF2 was used as the standard. The cell used

Jan 1, 1969

By H. M. Howe, E. C. Groesbeck

Fig. 1 shows a volute aging break which developed spontaneously in a hardened and tempered steel helmet between 19 and 38 days after it had been tested ballistically. A similar break, shown in Fig. 2, developed spontaneously in a similar helmet about 40 days after the ballistic testing. In this case the rupture occurred abruptly and with a loud report. The path of rupture in this second case, though much the less regular, is the more interesting of the two, in that it is an approximation to two parallel volutes centered at the point of impact of the projectile, just below D. Several weeks later, after the photograph for Fig. 1 was taken, a similar doubling of the volute crack occurred in this helmet, starting from the end of the eyelash crack near A and spreading thence to the left contra-clockwise for about 1/2 in. The negatives from which these pictures are made have not been touched up in any way, save writing the letters on them. In both cases the trajectory of the bullet was normal to the initial surface at the point of impact, and in both the helmet passed the ballistic test without detectable cracking, under a velocity of impact not far below that which usually causes perforation. The initial surface itself was very nearly spherical throughout the region covered by the break.

Jan 1, 1920

By E. B. Branson

Introduction to Geology, by E. B. Branson, W. A. Tarr, and W. D. Keller, revised-by Carl C. Branson. McGraw-Hill, 1952. $5.50.-Dealing with physical and historical geology, the book has been revised from an earlier edition. An attempt has been made to eliminate unnecessary detail in discussing processes and history. Revisions bring technical and statistical data up-to-date, and follow suggestions by teachers who used earlier editions. The book carries an eye witness account of the severe earthquake in Assam, India, in 1950 and the story of Paricutin and other major examples of volcanism. Charts summarize chemical weathering, and the results of metamorphisms. The book also contains many new illustrations, including aerial photographs. A History of Phelps Dodge 1834-1950, by Robert Glass Cleland. Alfred A. Knopf, 1952. $4.00.-The book traces the growth of Phelps Dodge from the day Anson Greene Phelps opened a small saddle shop in Hartford, Conn., to the present day. As the country grew, so did Phelps Dodge. The company took part in large affairs from its very beginning. It bought and sold, exported and imported, built factories and railroads, and widened its scope of operations economically and geographically. Entrance of Phelps Dodge into copper mining and the gradual giving up of other interests in favor of the new venture is traced.

Jan 1, 1952

By R. E. Mussler, F. E. Block, T. T. Campbell

An exploratovy study was made to deternzine the feasibility of preparing beryllium by the metallother-. mic reduction of beryllium oxide. The procedure involved heating a relatively nonvolatile metal reductant in contact with beryllium oxide in a vacuum. Beryllium vapors formed in the reaction were condensed as a coherent deposit on a heated surface. Reductants tested included tanthanun, yttrium, thorium, Th-Mg, and Zr- Ti alloys, and the hydrides of lanthaniir~z, yttriunz, and zirconiur?7,. Test ten7pevatures ranged from 1350'to 175O' C, and reaction times ranged frot 30 to 100 lzr. In most cases metal recoveries were lola, although yields close to 90 pct of theoretical were obtained with latzthanum, yttrium, and zirconium reductants. In most cases metal deposits were contanzinated by beryllides, /ls/cally of the Beln M or Bel3 M type. BERYLLIUM has a variety of unique properties including light weight (sp gr 1.85), low thermal neutron absorption cross section, high scattering cross section, excellent dimensional stability, high strength to weight ratio, high melting point (1285"C), high specific heat, and high thermal conductivity. Interest in beryllium as a structural material in aerospace and nuclear-reactor applications is based on these properties. In general, the potential of beryllium has been only partially realized, largely because of the brittleness of poly crystalline forms of beryllium, difficulties associated in its fabrication, and joining problems encountered in its use in structural applications. Several excellent books and monographs are available to those interested in the occurrence, extractive metallurgy, and utilization of beryllium.1"* Although an extensive amount of research on beryllium has been in progress during the past 10 years, much of the work has been concerned either with the so-called "ductility problem" or with the development of methods of fabrication and evaluation of properties of various commercial or purified grades of metal. A recent survey of the literature indicates that only limited efforts are presently being directed toward developing new methods for reducing beryllium compounds to metal. Two major commercial methods now used to produce beryllium are the magnesium reduction of beryllium fluoride and e lec trow inn ing of beryllium from fused sodium chloride-beryllium chloride salt baths. Only a limited amount of work has been done on the direct reduction of beryllium oxide. Major factors which complicate this method are the great stability of beryllium oxide and the reactive nature of beryllium metal. The stability of the oxide necessitates extremely high reduction temperatures and vacuum operation to liberate beryllium metal vapor and cause reactions of the following type to proceed: XBeO(s) +YM(s)-MYOX(s) + XBe(& As early as 1939, roll' used this reaction for the direct reduction of beryllia by zirconium and titanium, and later in 1952 ~a~el~ studied the reduction of beryl-

Jan 1, 1967

By Walter Renton Ingalls

Vague references to tin-deposits in Mexico are scattered throughout technical literature, and that country has been looked to as a likely source of a part of the world's supply of till at no very distant date; but thus far nothing but occasional small lots have come forward, so that the notion has arisen that these mines are either mythical or unworkable. So far as I am aware, there has not yet been published any description of the tin-deposits of Mexico except a few brief references; and this paper, based on a study of them made in 1892, is therefore offered.

Jan 1, 1896

By Edward Skewes

In view of the importance of the Cripple Creek district, the large amount of the publications concerning it, and the circumstance that many members of the Institute reside in it, or are familiar with it through repeated visits, it is surprising that our Transactions should have remained so long without any contributions on the subject. The same observations may be made with regard to the Witwatersrand, in South Africa, the other great productive gold-field of recent development. And I suppose the explanation is the same in both cases, namely, that the members of the Institute persoilally acquainted with the

Jan 1, 1897

By Ralph Hayden

I. INTRODUCTION. IN the wet concentration of ores there is always a certain amount of very fine material with which to contend, and which invariably carries such quantities of value that the treatment of it is worth while; commercially. This fine material usually contains that portion of the ore which hinders the separation of the mineral values: namely, the colloidal material resulting from the decomposition of certain constituents of the ore. The object of this paper is to show what efforts have been made to solve the slime problem as it occurs in the concentrator of the Washoe

Jan 8, 1913

By S. LeFevre

THE solution of the housing and sanitation problem in mining communities, keeping in view both economic and humanitarian aspects, demands the best thought of the management of such enterprises. Upon the solution depend the health and comfort of the employee and his family, and as a consequence his contentment and efficiency. The following description covers briefly the methods installed for Witherbee, Sherman & Co. The operation of the system has been for about two years under the direct supervision of T. A. Hammond, Land Agent, and I am indebted to him for a compilation of the results.

Jan 2, 1915