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ALEXANDER BRYDEN Alexander Bryden, clean of engineers in the anthracite mining field, and a member of the pioneer Pittston family, was claimed by death Wednesday, September 26, 1917. The announcement was not a surprise, as he had been in a critical condition for several days. Mr. Bryden had been in failing health for a year past, but his indomitable will kept him at his accustomed duties until quite recently. Two weeks before his death he attended the regular weekly meeting of the Board of Directors of the Miners' Savings Bank in Pittston, Pa. At that time he apparently felt that his end was fast approaching, as he bade farewell to his associates on the bank board. Until a few days before the end, he continued to give attention to business matters at his home, in preparation for the end, which he met unflinchingly. In the passing of Mr. Bryden, northeastern Pennsylvania loses one of the best-known mining engineers, and the community, a man who, throughout his long life, was actively interested in its social welfare and business prosperity. He was for many years prominent in the management of the mining operations of the Pennsylvania Coal Co., and at the time of his death held the position of consulting engineer of the Pennsylvania and Hillside Coal. Companies.

Jan 12, 1917

By HUGH E. McKinstry

OPENING the sessions of the Mining Geology Committee, the program on postwar mineral controls drew a larger attendance than any other session of the entire meeting. In view of its general interest, the papers of this session, or a substantial portion of them, are printed elsewhere in this issue. Whether control of mineral resources can help to promote peace, how controls could be applied and to whom, are questions so far-reaching that naturally no pat answer was agreed upon. In fact the discussion took on something of the flavor of a debate between those who favor strict control and those who felt that attempting to ration nations in peacetime would defeat its own ends. Discussion from the floor emphasized the difficulties in administering any international control and the $64 question, that no one cared to answer, asked by a courageous young lady who was induced to mount the rostrum for the purpose, was whether the United Nations should exchange mineral controllers to police each other.

Jan 1, 1944

By Paul M. Tyler

FULLY a decade ago, demand for ground mica began to exceed supplies of scrap mica from manufacturing operations and of waste block from feldspar and sheet mica mining in the United States, with the result that in recent years the market has absorbed larger and larger quantities of mica recovered as a by-product from clay washing,1 as a joint product with kyanite12 and by grinding schists. So far, only schists that contain a large percentage of mica have been utilized for making ground mica, but already there has been a good deal of wishful thinking with regard to recovering mica as an aid to the prospective working of low-grade gold ores and ores of certain base metals. With wet-ground mica selling at $60 to $100 a ton and even dry-ground mica worth over $20 a ton, many ores that could not be considered as otherwise workable under present conditions will show commercial possibilities if they can be made to yield even a relatively small percentage of salable mica. An interesting paper might be written on the coming role of industrial minerals as joint products of metal mines. It is largely a matter of markets. Many years ago I watched the mess left behind the gold dredges in the mountains of Colorado and thought of the Denver sand and gravel operators who prided themselves upon their canniness in providing devices for catching gold merely as an incident to their regular business of selling what we miners classed as "tailings." Nowadays almost every milling or mining operation near settled communities finds use for at least part of its waste for road material or concrete aggregate and several eastern iron mines have gone into the crushed-stone business. Promoters now mention fertilizer "filler" as potentially salable at all the way from $1 to $10 a ton, or whatever is needed to cover costs of mining and treating the "ore" and leave the metal values as "clear profit." In emulating the pork packers in their efforts to utilize "everything but the squeal,"

Jan 1, 1938

By H. J. Polta, R. W. Michelson

Discounted cash flow analysis is commonly used to evaluate the profit making potential of a business venture. The same method can be used to analyze the effects of varying physical and economic conditions upon the real cost of supplying a mineral commodity. If a fixed rate of return on a capital investment is specified, and the flow of cash, discounted at that rate, is just adequate to repay the investment over the life of the venture, the net present value of the venture is zero. At this condition it is possible to evaluate the unit cost of producing the mineral. It will be exactly equal to the selling price required to calculate a zero present value. Increasing a particular cost factor will not always increase the cost of supply by the same amount. For example, in iron production from magnetic taconite, an increased cost per ton associated with beneficiation would be integrated into the discounted cash flow model along with local, State, and Federal taxes, depletion and depreciation allowances, resultant increased unit recoveries, and all of the other related component cost factors. Rather than adding to the cost, the factor may have a positive, instead of a negative, effect on the discounted cash flow and cause a decreased cost of supply. This value can be determined by a computer model which iterates the necessary selling price until the net present value is essentially zero. The discounted cash flow evaluation model lends itself particularly well to an application of the Monte Carlo simulation method for calculating a probability distribution of iron unit cost resulting from the probability distributions of the component cost factors.

Jan 1, 1969

The following is an incomplete list of members and guests who called at Institute headquarters during the period Apr. 10, 1919, to May 10, 1919. Arthur K. Adams, Spencer, Mass. Ensign Floyd D. James, U. S. S. Fulton. W. T. Bates, New York City, N. Y. J. Harry Johns, Thorsden, Woking, A. D. Brokaw, Washington, D. C. England. E. H. Clausen, San Francisco, Calif. W. F. Jones, Rock Springs, Wyo. W. M. Corse, Mansfield, Ohio. E. L. Lasier, Washington, D. C. E. O. Daue, Philadelphia, Pa. John M. Lovejoy, New Rochelle, N. Y. G. D. Dub, Washington,, D. C. 2d Lieut. James F. Magee, Lancaster, S. B. Eaton, Dover, N. J. Pa., Sherman Eaton, Smethport, N. C. Ernest Marquardt, Casper, Wyo. J. A. Endweiss, La Jolla, Calif. Geo. B. Marshall, Abangarez, Costa Edgar W. Engle, North Chicago, Ill. Rica. 2d Lieut. Maxwell E. Erdofy, New York Benj. L. Miller, So. Bethlehem, Pa. City, N. Y. Major Desaix B. Myers, Camp Mills. Chas. A. Fellencer, Allentown, Pa. Edmund Newton, New York City, N. Y. Arthur Feust, Joplin, Mo. Seely B. Patterson, Jr., Allentown, Pa. Ensign Harold P. Ford, U. S. S. Radnor. Wm. R. Pearson, New York City, N. Y. A. D. R. Galloway, Accra, West Africa. Harold C. Price, Langeloth, Pa. R. C. Gosrow, Milwaukee, Wis. T. C. Roberts, East. Orange, N. J. C. A. Grabill, El Paso, Tex. P. H. Royster, Washington, D. C. Hobart A. Hanks, San Francisco, Calif. W. H. Staver, New York City, N. Y. John L. Henning, Lake Charles, La. N. L. Wimmler, Bangkok, Siam. 1st Lieut. J. Parke Hook, Philadelphia, Capt. Jay P. Wood, New York City, Pa. N. Y. An item in the May Bulletin made it appear that Frank W. DeWolf had just become connected with the State Geological Survey of Illinois. This was one of the inadvertences of war. Mr. De Wolf has been Director, or Chief, of the State Geological Survey for approximately ten years. Through the courtesy of the Governor of Illinois, lie was loaned to the Bureau of Mines for about seven months, after which period he resumed his former position.

Jan 6, 1919

By Richard W. Bayley

The Atlantic City district encompasses several districts and has been previously called by different names, e.g., Atlantic gold district, Atlantic City-South Pass mining district, and Sweetwater mining district. The district is located in a terrane of folded and faulted early Precambrian metamorphic rocks which lies near the south end of the Wind River Range in Fremont County, Wyoming, Historically it is a gold district of little production, but today is an iron district of considerable importance. Gold was discovered in placer deposits about 1842 and in quartz-arsenopyrite veins about 1867, after which there occurred a mining boom lasting a few years. Minor, intermittent gold production from placers and lodes has continued to date, but the total production has probably not exceeded a few millions of dollars. Past lode mining was generally shallow ( in the oxidized zone), the deepest about 3 60 feet. The deeper, less oxidized and sulfide ores on the same lodes have not been explored. They appear to hold the only hope for future gold mining. Sedimentary iron-formation, similar to the Lake Superior taconite, occurs in the northern part of the district. Locally, where the ironformation is thickened by folds and faults, sufficient tonnages are present to be minable, as at Iron Mountain, where the U.S. Steel Corporation produces about 1.3 million tons of iron-ore pellets annually. Exploration of the iron deposits began in 1954, and the first ironore pellets were shipped to Provo, Utah in August 1962. Indicated reserves of iron-formation (about 30 per cent Fe) are reported to be about 300 million tons.

Jan 1, 1968

By S. D. Strauss

The marketing of nonferrous metals and of the ores and concentrates from which these metals are recovered is a fascinating trade, international in character, sensitive to every change in the economic tide, and complex in its organization. Each individual metal has its own marketing mechanism; no two are exactly alike. The differences sometimes are a matter of tradition rather than of necessity, but usually they have developed because of the very nature of the problems of producing or consuming the individual metal. This description, because of limitations of space, can do no more than indicate the major aspects of the trade and touch lightly on the marketing structure of each metal. The dictionary states that a market is a "meeting of people for selling and buying." In the case of nonferrous metals this meeting may occur on a half-dozen different occasions between the time the ore has been first mined and the time the refined metal is available for use by industry; or it may not occur at all until after the metal itself has been rolled, drawn, stamped, cast, or forged into a useful semifabricated shape. To illustrate: A Chilean miner may sell his small ore production to a custom mill, which produces concentrates that are sold to an ore dealer, who finances shipments of the concentrate to a custom smelter, which buys them for conversion into blister, to be subsequently refined into electrolytic copper (sometimes by a refinery having no corporate ties with the custom smelter) and sold. Conversely, aluminum production is mostly by integrated concerns that mine bauxite, convert it to alumina, smelt that to produce aluminum, and then fabricate that into semifinished or even finished products before title to the material changes hands for the first time. Some nonferrous ores are not converted into metal at all but are sold by the miners or dealers directly to the ultimate consumers. A good example would be chrome ores used by the chemical industry. And of course a substantial part of the commerce in nonferrous metals is in scrap, which is the reconversion into useful form of metals that have long since been mined and smelted. Thus, one-third of all the lead used in the United

Jan 1, 1964

By John G. McLain

OF all the zinc that the world consumed in 1936-'38 the United States took about 31 per cent, and almost 14 per cent of the world's zinc supply in that period was used for galvanizing purposes in the United States. Further examination of the statistics shows that about 71/2 per cent (147,500 tons in 1939) of the world zinc consumption goes into the galvanizing of sheets in the United States, which is what I am going to talk about in this paper. There is nothing especially new about galvanizing; in every year since 1921 somewhere between 41 and 49 per cent of the country's zinc consumption has been used for this purpose, and yet few people not specialists in its manufacture know much about how it is made. You take an iron or steel sheet and dip it in molten zinc and there you have a galvanized sheet-that about epitomizes popular knowledge of the subject even among engineers.

Jan 1, 1941

These pages may be used as order sheets. Mark the number desired opposite title of pamphlet wanted, add your name and address, tear out the sheets and mail them to us. Single orders 25 c. Pamphlets 10 c. each in lots of three or more. Pamphlets 5 c. each in lots of fifty or more. These prices prevail for orders for pamphlets of the same or different titles, when cash accompanies order. The pamphlets listed on the following sheets are advance copies printed to facilitate discussion at the meetings of the Institute. They are offered for sale at the reduced prices given above as long as the supply lasts. This list is published in the Bulletin in order that members may have the first opportunity to secure pamphlets, which sometimes are in such great demand that the supply is exhausted before the wants of members can be supplied. The following list includes only a fraction of the pamphlets that have been published by the Institute. Any other paper published by the Institute may be obtained for the price of $1, except those published in Volume XXXI, which are rare. The Institute is still selling back volumes of Transactions at reduced prices, but some of these volumes are becoming rare and members who desire to complete their sets of these very important books on mining and metallurgy are advised to send in their orders as soon as convenient. The attention of members is also called to the bibliographical index of the science of ore deposits contained in the Emmons Volume which is selling at $3 in paper and $4 in half morocco. The Posepny Volume is already exhausted and members who do not get in their orders for the Emmons Volume at the present reduced price may soon find themselves unable to obtain it on such favorable terms.

Jan 8, 1917

By S. D. Strauss

The marketing of nonferrous metals and of the ores and concentrates from which these metals are recovered is a fascinating trade, international in character, sensitive to every change in the economic tide, and complex in its organization. Each individual metal has its own marketing mechanism; no two are exactly alike. The differences sometimes are a matter of tradition rather than of necessity, but usually they have developed because of the very nature of the problems of producing or consuming the individual metal. This description, because of limitations of space, can do no more than indicate the major aspects of the trade and touch lightly on the marketing structure of each metal. The dictionary states that a market is a "meeting of people for selling and buying." In the case of nonferrous metals this meeting may occur on a half-dozen different occasions between the time the ore has been first mined and the time the refined metal is available for use by industry; or it may not occur at all until after the metal itself has been rolled, drawn, stamped, cast, or forged into a useful semifabricated shape. To illustrate: A Chilean miner may sell his small ore production to a custom mill, which produces concentrates that are sold to an ore dealer, who finances the shipments of the concentrates to a United States custom smelter, which buys these' concentrates for conversion into blister, which is subsequently refined into electrolytic copper and sold. Conversely, much of the production of aluminum is in the hands of integrated concerns that mine bauxite, convert bauxite to alumina, smelt the alumina to produce aluminum, and then fabricate the aluminum into semifinished or even finished products before title to the material changes hands for the first time. Some nonferrous ores are not converted into metal at all but are sold by the miners or dealers directly b the ultimate consumers. A good example would be chrome ores used by the chemical industry. And of course a substantial part of the commerce in nonferrous metals is in scrap, which is the reconversion into useful form of metals that have long since been mined and smelted. Thus, one-third of all the lead used in the United

Jan 1, 1959

By Paul M. Tyler

Fully a decade ago, demand for ground mica began to exceed supplies of scrap mica from manufacturing operations and of waste block from feldspar and sheet mica mining in the United States, with the result that in recent years the market has absorbed larger and larger quantities of mica recovered as a by-product from clay washing,1 as a joint product with kyanite12 and by grinding schists. So far, only schists that contain a large percentage of mica have been utilized for making ground mica, but already there has been a good deal of wishful thinking with regard to recovering mica as an aid to the prospective working of low-grade gold ores and ores of certain base metals. With wet-ground mica selling at $60 to $100 a ton and even dry-ground mica worth over $20 a ton, many ores that could not be considered as otherwise workable under present conditions will show commercial possibilities if they can be made to yield even a relatively small percentage of salable mica. An interesting paper might be written on the coming role of industrial minerals as joint products of metal mines. It is largely a matter of markets. Many years ago I watched the mess left behind the gold dredges in the mountains of Colorado and thought of the Denver sand and gravel operators who prided themselves upon their canniness in providing devices for catching gold merely as an incident to their regular business of selling what we miners classed as "tailings." Nowadays almost every milling or mining operation near settled communities finds use for at least part of its waste for road material or concrete aggregate and several eastern iron mines have gone into the crushed-stone business. Promoters now mention fertilizer "filler" as potentially salable at all the way from $1 to $10 a ton, or whatever is needed to cover costs of mining and treating the "ore" and leave the metal values as "clear profit." In emulating the pork packers in their efforts to utilize "everything but the squeal," mining engineers may go too far; on the other hand, they should not let

Jan 1, 1942

By Paul M. Tyler

Fully a decade ago, demand for ground mica began to exceed supplies of scrap mica from manufacturing operations and of waste block from feldspar and sheet mica mining in the United States, with the result that in recent years the market has absorbed larger and larger quantities of mica recovered as a by-product from clay washing,1 as a joint product with kyanite12 and by grinding schists. So far, only schists that contain a large percentage of mica have been utilized for making ground mica, but already there has been a good deal of wishful thinking with regard to recovering mica as an aid to the prospective working of low-grade gold ores and ores of certain base metals. With wet-ground mica selling at $60 to $100 a ton and even dry-ground mica worth over $20 a ton, many ores that could not be considered as otherwise workable under present conditions will show commercial possibilities if they can be made to yield even a relatively small percentage of salable mica. An interesting paper might be written on the coming role of industrial minerals as joint products of metal mines. It is largely a matter of markets. Many years ago I watched the mess left behind the gold dredges in the mountains of Colorado and thought of the Denver sand and gravel operators who prided themselves upon their canniness in providing devices for catching gold merely as an incident to their regular business of selling what we miners classed as "tailings." Nowadays almost every milling or mining operation near settled communities finds use for at least part of its waste for road material or concrete aggregate and several eastern iron mines have gone into the crushed-stone business. Promoters now mention fertilizer "filler" as potentially salable at all the way from $1 to $10 a ton, or whatever is needed to cover costs of mining and treating the "ore" and leave the metal values as "clear profit." In emulating the pork packers in their efforts to utilize "everything but the squeal," mining engineers may go too far; on the other hand, they should not let

Jan 1, 1942

By W. P. Barba

IN THE early summer of 1917, it became evident that the then existing sources of supply of guns and gun forgings were totally inadequate for the enormous and rapidly growing requirements of the Ordnance Department of the Army, so arrangements were made with sixteen makers of other products to take up the manufacture of guns and gun forgings. Nine of these makers were required to produce their own steel from the raw materials and convert it into rough machined gun forgings; the others finished and assembled these forgings into completed guns. In December, 1914, four of these makers of steel and rough gun forgings were instructed to manufacture the same amount of the 6-in. and 9.5-in. guns and howitzers. It, therefore, seemed practical .and profitable to assemble these makers into a small group, together with the officers of the Ordnance Department, and provide standard 'equipment in each of the four works for the production of these two types of guns. The advantages of this cooperation were immediately manifested, and there commenced an interchange of shop practice and a free discussion of facilities and methods that covered not only the equipment but the manufacturing processes.

Jan 1, 1920

By AIME AIME

THE following paragraphs, constituting the concluding portion of the Annual Report of the Council for 1903, have been withheld from publication until now, in order to make them as accurate and complete as possible. They will be published in Volume XXXV. of the Transactions in their proper place at the end of the said Annual Report. Franklin Ballou was born in Pittsburg, Pa., May 29, 1845. He was the son of an old resident, Arthur Ballou, a manufacturer and wholesale dealer in vinegar. In early youth Franklin attended the Western University of Pittsburg, but left school at the age of 16 to become book-keeper for his father, upon whose retirement from business, in 1868, he associated himself with Walter C. Childs, of Pittsburg, in the manufac¬ture of furnace-grates and asbestos-cement for blast-furnaces. This firm was known as W. C. Childs & Co., and did a success¬ful business for several years. In 1869 Mr. Ballou married Miss May S. Wilson, daughter of Judge Wilson, of Lewistown, Pa. In 1876 he spent several months traveling in the West and studying the mining industry, which greatly interested him. In consequence of this journey, he wound up his business in Pittsburg and removed in 1877 to Georgetown, Colo., where for several years he conducted a sampling-works, and built up an extensive business as an agent for the sale of ores, besides engaging to some extent in mining enterprises. , It is said that he controlled at one time about one-eighth of the output of the Leadville mines. In the early 80's, he became Vice-President and General Manager of the Bimetallic Smelter at Leadville, of which Mr. David H. Moflat was the principal owner. This was practically the first successful demonstration of pyritic smelting in Colorado. Upon the sale of the works in 1897 to the American Smelting and Refining Co., Mr. Ballou retired

Jan 1, 1905

By S. A. Levy, J. D. Wood, J. F. Libsch

A study of the preparation and characteristics of a sevies of Fe-C-N alloys has been conducted. X-ray, microhardness, and metallographic data from a series of single-phase alloys produced by controlled nitriding of carburized foils are reported. The existence of a, y', and E carbonitride has been confirmed and it has been found that y' is the hardest of these three phases. These results have been used to interpret the structures observed in nitrided steels. ThIS paper represents the second phase of a three-part study concerning combined nitriding and induction hardening. The first part' reports the engineering properties (depth hardness, fatigue, corrosion, and tempering resistance) obtained when seven different steels were subjected to the combined surface hardening treatment. The present paper concerns the nature of a series of single-phase alloys prepared by controlled nitriding of carburized foils. The objective was to simulate the various layers present in the as-nitrided steels. A third paper will report data concerning induction hardening of the foils and will attempt to set forth a mechanism for the high hardness obtained with the combined treatment. Studies of nitriding generally fall into three categories. The first were performed with bars using conventional nitriding procedures, thus yielding a nitrogen gradient and a series of phase layers near the surface.2-6 Such studies were complicated by the presence of the nitrogen gradient, for it was difficult to correlate microhardness and X-ray data with chemical composition. There were always complications due to penetration of the X-ray beam which yielded data influenced by underlying layers. Similar difficulty was experienced in taking hardness readings on a tapered specimen or in isolating various layers by machining. A second group of investigations was primarily concerned with establishment of regions in the Fe-N7,9,10 or the Fe-C-N phase diagram.8 These were performed with powder specimens which were nitrided in am-monia-hydrogen mixtures to produce a series of single-phase specimens. Unfortunately, the powder specimens were not amenable to either microstruc-ture or microhardness study. The third was essentially a compromise of the first two. Bose and Hawkes," using 0.005-in.-thick iron foils, were able to obtain microhardness, microstruc-ture, composition, and X-ray data on Fe-N alloys of eutectoid composition by equilibration in ammonia-hydrogen mixtures at 1290°F. To obtain a better understanding of the nitriding process and the characteristics of the phases in ni-trided plain carbon steels, the present investigation was undertaken. The investigation was patterned after that of Bose and Hawkes with the exception that nitriding was performed at 930°F (below the eutectoid temperature), as in the case of conventional nitriding. In addition to gaining some understanding of the source of high hardness of nitrided and induction-hardened steels, found in a previous study,' this investigation was concerned with the possibility of controlling the phases present in a nitrided case through the use of ammonia-hydrogen mixtures. Knowledge of the properties of each phase and the conditions necessary for its production could make it possible to avoid undesirable surface layers in nitriding. EXPERIMENTAL PROCEDURE Specimen Preparation. A specimen thickness of 0.005 in. was selected to insure that a uniform nitrogen concentration could be obtained in a reasonable length of time by equilibration in an ammonia-hydro-gen atmosphere. The starting material was a vacuum-cast ingot of pure iron, the major impurities of which were: C, 0.003 pct; 0, 0.014 pct; S, 0.004 pct; N, 0.003 pct.* 'Compositions are quoted as weight percent except as noted. The ingot was heated to 1500°F in a nitrogen atmosphere and forged to a slab 0.25 in. thick. The material was then reduced to 0.005 in. by alternately cold rolling and annealing in a nitrogen atmosphere at 1600°F. This material was divided into five groups of specimens which, after carburizing, yielded the following carbon contents: 0.003, 0.28, 0.36, 0.46, and 0.74 pct C. The carburizing was performed by the Leeds and Northrup Research Laboratories, using a controlled "carburizing potential" which yielded a uniform carbon concentration throughout the cross section.

Jan 1, 1970

By H. O. Hofman

WITH the exception of lead sulphate, all common metallic sulphates are completely decomposed upon heating into metallic oxide, sulphur trioxide, sulphur dioxide and oxygen. Some give up their trioxide readily at a low temperature, others require considerable heat and much time to be completely freed from sulphur. Kerl in 1881 arranged the principal metallic sulphates as they are decomposed by a rising temperature in the following order: silver, iron, copper, zinc, nickel, cobalt, manganese and lead, lead sulphate being decomposed only slightly at a white heat. The researches of Bradford, published in 1903, show, however, that ferrous sulphate is decom¬posed at 590° C., cupric sulphate at G53° C. and argentic sulphate at 1,095° C. By the present investigation it will be seen that zinc sulphate is decomposed at 739° C. As far then as our present knowledge goes, the order in which the decomposition of the leading metallic sulphates takes place is the one given in Table I.

Jan 1, 1905

By PERCY E. BARBOUR

SECONDARY copper1 has &come more or less of a bugbear generally. What is its influence is often the subject of heated argument. The inedapable fact usually quoted is that since in 1929 primary production of copper in the United States was 1,026,348 tons and secondary production was 626,550 tons, there- fore, 0.6 lb. of secondary is produced for every pound of primary, and "How can you get around that?" The matter seems very plain, now that I have reached my conclusions, but they are the result of much laborious study and research. I shall show that' the production of secondary copper is not 0.6 per lb. of primary, in spite of statistical appearances; that the production of secondary is a function of primary production rather than of price; that secondary production has 'only a sub-. ordinate influence on the price of copper and then only in abnormal times; that there is not an accumulating reservoir of secondary from which the country is some- time to be drowned in copper, as is believed by some, or a reservoir from which we are going to draw much needed and more or less inexhaustible stores in the future, as is believed by others; and finally, that the United States always produces more copper than it uses and exports the surplus. These are all controversial points, and for that reason and to anticipate argument I have set forth my reasoning in considerable detail.

Jan 1, 1931

By Zay Jeffries

Tungsten has the highest melting point of all the known metals, namely 3350 C.; it is one of the hardest of the metals; it has the highest equiaxing or recrystallization temperature after strain hardening, of any pure metal known. It is particularly distinguished because, when composed of small equiaxed grains, it is extremely brittle and fragile at room temperature, and when possessing a fibrous structure it may be ductile and pliable at room temperature. The common ductile metals act in exactly the opposite manner in this respect. The present paper will include a brief note regarding the manufacture of wrought and ductile tungsten. The metallography of wrought and ductile tungsten in the various stages of manufacture will be considered more or less in detail. The general relationships between the properties of tungsten and other metals will also be considered. A discussion will be given explaining why fibrous tungsten is ductile at room temperature, even though past experience with other metals would indicate that it should be brittle. Finally, a brief note regarding some new fundamental metallographic propositions relating to all metals will be given. Manufacture of Wrought and Ductile Tungsten Up to about 10 years ago, it had not been possible to work tungsten mechanically. About the year 1908, Dr. William D. Coolidge, of the General Electrie Go., produced ductile tungsten from what was then supposed to be an inherently brittle metal and which, in fact, was inherently brittle in its normal state, that is, when composed of equiaxed grains. Since that time many products, chief among which are the filaments for electric incandescent lamps, have been made from wrought and ductile tungsten. Tungsten is produced chiefly from the minerals wolframite and scheelite.1-8 The ores may be reduced in many ways. For example, the ore may be fused with alkali carbonates and the fusion dissolved in water; sodium tungstate is formed, which is soluble in water. This

Jan 1, 1919

By Robert C. Temps

The history of iron ore milling in Chile can be divided into two periods: the first, which lasted about 40 years, ended in 1952 and the second continues today. During the first period, Bethlehem Chile Iron Mines Co. was the sole shipper and El Tofo, the only mine. That situation was forever altered in 1952 when several small independent companies began to sell ore. The success of these companies triggered programs of exploration which can only be described as a "boom" during the past five years.

Jan 1, 1963

By Goerge F. Weaton

Since 1909, when an agreement between Minnesota's Tax Commission and the University of Minnesota's School of Mines was worked out, it has been the annual responsibility of the School to evaluate and classify the iron ore deposits within the State. These unique duties of an academic institution have provided School officials with an excellent view of the past, present and probable future of the mining industry in Minnesota as the average grade of iron ore (excluding taconite) * diminishes while at the same time it competes with beneficiated taconites and foreign high-grade ores for use in America's eastern blast furnaces. SYSTEM OF EVALUATION In the latter part of November of each year, the Mining Division of the Department of Taxation makes a preliminary study of the active mines which the Department wants the School of Mines to review. These are discussed with the engineers of the Ore Estimate Division of the School of Mines and with the mining companies. After these discussions, a list of the mines of each of the major operating companies is submitted to the Ore Estimate Division of the School of Mines with the request that these properties be reviewed by them as of the next assessment date (May 1st). At the same time, a letter is sent to the mining companies requesting that they submit to the Division their own estimates on the selected mines operated by them, together with all computations, drill records, maps and cross-sections. The mining companies are re- quested to send in this information during the first half of the year, and, as far as is possible, they have always complied with this request promptly. Much of this information received by the School of Mines is of a confidential nature and is treated as such.

Jan 1, 1965