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By E. P. Jennings

The abundance and value of the tellurium minerals of Colorado is well known, but, as yet, few analyses have been made of them, and I offer these as a small contribution to the chemistry of these valuable ores. 1. Native Tellurium.—The specimens from which the analyses of this mineral were made are from the " John Jay" Mine, Boulder County, Colorado, where it occurs in quite large masses, though mixed with more or less silica and iron pyrites. It is usually a finegrained, tin-white mineral, but sometimes occurs in distorted, hexagonal prisms in cavities in the quartz. Before the blowpipe it gives the reactions for tellurium, sulphur and iron; by cupellation, it yields a small amount of gold. An analysis of a coarsely crystallized specilnen gave the following results : Specific gravity, 5.10.5. Tellurium,.........68.40 Gold, :.........1.36 Iron pyrites,........24 92 Ferric oxide,.....4.37 Silica and silicates,........11.54 Silver, lead, and mercury,... traces. 100.59 Deducting the pyrites, iron oxide and silica, we have for the con]position of the mineral: Tellurium,..........97.78 Gold,.......... 2.27 100.00 Or, considering the gold to be in combination with tellurium to form sylvanite, we have : Nativc tellurium,........96.50 Sylvanite (An, Te3,),........4.50 100.00

Jan 1, 1879

By Perry Harrison

THE increased use of sintering for the beneficiation of iron ores and the reclaiming of flue dust creates a lively interest in sintering costs and, economics. The character of material sintered and geographical location of plants so radically alter sintering costs and economics that it is well to understand at least the basic elements which control such changes. The following cost factors are believed to be roughly approximated for large-scale Dwight-Lloyd 'continuously operated sinter-machine installations located anywhere. PER CRUDE TON Labor, supplies and repairs 0.15 Power 6.5¢ X kw-hr. rate ? Plant overhead and administration 0.05 Depreciation per ton annual capacity 0.05 Fuel: 6 per cent coke breeze or equivalent minimum ? 1 per cent coke breeze additional for each 5 per cent free and combined water in ore or dust ? Ignition distillate at 0.6 gal. per ton ? PER SINTER TON Royalty on Ore 0.10 Royalty on Flue Dust 0.15 PER CRUDE TON "Winter expense"; i. z., the cost of the five months enforced idle . period for plants tied in to Great Lakes transportation season 0.03 Using the foregoing data, it is possible to roughly approximate the cost of efficient sintering at any location for. any ore, viz:

Jan 1, 1932

By J. B. Clemmer

PRODUCTION of magnesium metal in the United States during the past decade has increased from less than 600,000 lb. in 1928 to more than 4,800,000 lb. in 1938.1 The growing industry has stimulated interest in methods of production and in sources of raw material. All of the present domestic production is from brines. However, the availability of large tonnages of magnesite in the state of Washington, together with the possibility of cheap power, have created interest in the utilization of magnesite for the production of magnesium metal as well as for other purposes. Magnesite, the carbonate of magnesium (MgC03), usually is associated with lime-stone (CaCO3) and dolomite (MgC03 CaCO3). It occurs in crystalline and microcrystalline (sometimes termed amor-phous) forms.2 The more common crystal-line mineral is found in various shades of white, gray, yellow and brown, the colors being due to impurities, chiefly iron. Magnesite has a hardness of 3.5 to 4.5 and a specific gravity of 3.0 to 3.1. It forms rhombohedral crystals in the hexagonal system, having a vitreous, pearly luster. The quarries and mines of the Northwest Magnesite Co. near Chewelah, Wash., are large producers of magnesite for refractories.

Jan 1, 1940

INDEX TO TRANSACTIONS After a delay of many months, which is very much regretted, but which, it is hoped, will be one means of insuring a volume of accuracy where accuracy is very important, the Institute now has for distribution copies of the index of Volumes XXXVI to LV, inclusive. This is more than a mere index off names of authors and titles of papers. Every important topic under consideration by author or discusser is introduced under such key-word as will enable an engineer to locate the desired information with the minimum expenditure of time. This index sells for $5* in half morocco binding and $4*. in paper covers. With the index of Volumes II to XXXV (which sells for $5 in half morocco and $4 in paper covers), it forms a complete index of the first fifty-five volumes of the Institute's Transactions. These collective indexes are very valuable to members of the Institute, enabling them to look up matters in their own library; if they have the volumes to which the indexes refer, they can get the information at once, and, if not, they can readily determine whether or not a visit to a nearby public library is desirable.

Jan 7, 1918

By Ben B. Cox

Oil produced in Iraq for export during 1938 was 31,354,090 bbl., or a daily average of 85,901 bbl; This is an increase of 182,614 bbl., or 0.5 per cent over 1937. All oil exported was produced from the Kirkuk field. The Khanaqin Oil Company, Ltd., a subsidiary of the Anglo-Iranian Oil Company, Ltd., continued to supply local market requirements from its Naft Khaneh field in the Transferred Territories. Slightly more than 32,000,000 bbl. was produced in Iraq, a small part of which was used in field operations. During the year 12 wells were completed and 9 wells were drilling at the end of the year. Of the completions, 5 were producers and 1 was an oil-water level observation well in proved fields, and 6 were listed as failures. Basrah Concession The outstanding event of the year was the granting, by the Kingdom of Iraq, of a 75-year concession embracing approximately 89,000 sq. miles to the Basrah Petroleum Company, Ltd., a British company with French and American participation. The concession covers all parts of the Kingdom, its territorial waters, islands, submerged lands, and its interest in the Neutral Zone separating Iraq and Saudi Arabia that

Jan 1, 1939

One-half fare return rate again available to members of the Institute and dependent members of their families. DON'T FORGET YOUR RAILROAD CERTIFICATE Over 300 members of the A. I. M. E. and dependent mem-bers of their families attending the last annual meeting se-cured return railroad tickets at half price by means of the railroad certificate, thereby saving several thousand dollars. DIRECTIONS 1. Be sure to obtain your railroad certificate when pur-chasing your railroad tickets for the meeting or you will lose money. 2. Purchase your tickets at regular one-way adult tariff fare between the dates specified for your territory in the accom-panying table. 3. Present your certificate for valida-tion at Institute headquarters in New York immediately after registration. Certificates will be validated on Feb. 21 and 22 between 9 a. m. and 5.30 p. in. 4. You must use your return half-rate tickets not later than Feb. 27. 5. Use the same route for both going and return trip. PLEASE REMEMBER THIS 1. Unless-250 certificates are validated at headquarters it will be impossible for anyone to secure the reduced rate. 2. Unless you secure a certificate you cannot take advantage. of the half-rate return fare, even if the necessary 250 certificates are validated.

Jan 2, 1928

By Ben B. Cox

Oil produced in Iraq for export during 1938 was 31,354,090 bbl., or a daily average of 85,901 bbl; This is an increase of 182,614 bbl., or 0.5 per cent over 1937. All oil exported was produced from the Kirkuk field. The Khanaqin Oil Company, Ltd., a subsidiary of the Anglo-Iranian Oil Company, Ltd., continued to supply local market requirements from its Naft Khaneh field in the Transferred Territories. Slightly more than 32,000,000 bbl. was produced in Iraq, a small part of which was used in field operations. During the year 12 wells were completed and 9 wells were drilling at the end of the year. Of the completions, 5 were producers and 1 was an oil-water level observation well in proved fields, and 6 were listed as failures. Basrah Concession The outstanding event of the year was the granting, by the Kingdom of Iraq, of a 75-year concession embracing approximately 89,000 sq. miles to the Basrah Petroleum Company, Ltd., a British company with French and American participation. The concession covers all parts of the Kingdom, its territorial waters, islands, submerged lands, and its interest in the Neutral Zone separating Iraq and Saudi Arabia that

Jan 1, 1939

By John A. E. M. Church

THE prospector's pan was the first implement used for saving gold, and its action is so effective that it has never been equalled for thorough work. Copper plates, blankets, sluices, and amalgamators of several patented designs have thrust it aside, but in spite of all the advances made there is no dispute among experienced men as to the comparative thoroughness of the work done by it and its rivals. When its rivals are doing their best, the pan can take their discarded refuse and prove their inefficiency by producing from it not only gold, but even the mercury which has been lost from the machines themselves. The trouble with the pan has always been that it was only a tool. Man was the machine that moved it. His work was high-priced, the quantity treated small, and it was impossible to use the pan for any but the richest sands. As a consequence the best gold-saving appliance known has been discarded for years and replaced by machines of inferior excellence, but which could more than make up for their limited ability in saving gold by their capacity for treating great quantities of ore. Mr. Peck is one of the old-time amalgamators of the Comstock district, and the first idea of the new machine came to him as he used to pan below the tailrace of his mill. No matter how fine the work of the mill was, the pan invariably proved that better could be done. The tailings always contained gold, silver, and mercury. This state of things is just as true to-day, after all the improvements that have been made, as it was then, and the much-vaunted method of the " Washoe process" consists in extracting 72 per cent. of the gold and silver by one operation, and then repeating this operation half a dozen times to get out about one-third of the remainder. With all the advances of twenty years in milling, there is nothing more crude in metallurgy than the treatment of tailings in many of the large mills of the West.

Jan 1, 1880

By John A. Church

Jan 1, 1880

By James Aston

A proper consideration of this subject is not confined to the technical channels of production and metallurgy. It concerns an industry, and should cover economic aspects which are of material importance in any program of development. The discussion may logically be treated under three subdivisions, as follows: (1) manufacture, (2) characteristics related to quality of material; (3) adaptability and exploitation of product. Manufacture of Wrought Iron The manufacture of wrought iron is the most ancient art of the ferrous metal industry. The eighty years or less of existence of processes identified with our modern "Age of Steel" is a relatively brief interval compared with the several thousand years associated with the production of wrought iron by man. From the primitive early methods of production, manufacture for many centuries followed the line of direct reduction. There were developments as experience was gained through the years; but man's needs for a strong, ductile, forgeable product were met by reducing the ore to metallic iron in a single-stage operation. Following the development several centuries ago of what has become our modern blast-furnace operation, manufacture of wrought iron was gradually transformed into a two-stage method of first producing cast iron and then refining this to the desired degree of forgeability; the forerunner in principle of today's scheme of manufacture of steel. The product retained the essential characteristics of highly refined base metal with iron-silicate slag incorporation, which were associated with the material resulting from direct reduction methods. Cort's invention of the puddling process in 1784 is a landmark in wrought-iron manufacture. It consisted essentially in adapting a coal-fired reverberatory furnace to the refining operation; thus lifting the industry out of the slough of

Jan 1, 1935

By Oliver Bowles

PRICES of quartz sold in the United States in 1938 ranged from $1.15 to $36,000 a ton. This startling variation was due simply to the differences between glass sand and rock - crystal, materials that are virtually the same in composition. It illustrates the complexities in qualities, uses, and values of industrial minerals. It is generally stated that mineral deposits are exhaustible resources which can never be replaced when depleted. This statement is no longer true with respect to certain industrial minerals now recovered in increasing quantities from that most inexhaustible of all sources of supply, the ocean. Salt has long been obtained from sea water, particularly on the Pacific Coast, and reference was made a year ago to the large bromine recovery plant at Wilmington, N. C. Now the Westvaco Chlorine Products Corp. is operating a large plant at Newark, Calif., having a capacity sufficient to recover daily from the ocean raw materials that will produce 60 tons of various magnesium products. Lime is used to precipitate the magnesia from salt-water bittern. The products are chiefly magnesium carbonate for chemical uses, periclase and other refractories, and oxychloride cement for flooring.

Jan 1, 1939

By A. D. Hughes

A relatively small area in Malaya, about 200 miles long by 40 miles wide, is the most important source of tin in the world. Some tin is recovered in other parts of the peninsula. Of the tin mined, 98 pct is recovered from alluvial deposits. From 1935 to 1941 the average annual world production of tin was 190,000 tons. The average annual production from Malaya during the same period was 62,000 tons or about one third of the total. Other producing countries, in order of importance, were the Netherlands East Indies 34,000 tons, Bolivia 30,000, Belgian Congo, Nigeria, Siam, Burma, China, and a few others with smaller amounts. The serious shortage of tin during the war period was due to the fact that the Japanese were occupying Malaya, Netherlands East Indies, Siam, Burma, and China which, together, formerly were producing 65 pct of the world supply.

Jan 1, 1949

By Henry D. Hibbard

THIS article aims to clarify the use of some terms often occurring in writings on iron and -steel, and also to suggest several new short abbreviated names for some of the things related to the subject which now are indicated by phrases. Crude or Crude Iron The name crude or crude iron is recommended for the iron produced from ore by the blast furnace. When necessary it can be specified as pig iron when in the form of pigs (usually cold), or as molten iron, commonly called hot metal to distinguish it from cold iron in pigs. The product of a direct process of making wrought or malleable iron from ore is not included.

Jan 1, 1924

By Martin A. Moyers

THE nation's effort to win the war speedily is reflected in current trends in coal utilization, as in all other fields of our lives. In all industries, wherever coal is used for the production of heat and power the emphasis is on getting the most useful result with the least expenditure of matt.ria1. In addition to carrying its own share of the load, increased as it is by the demands of war industry, coal has had to fill in for the other fuels, mainly petroleum products, whose distribution from their more distant sources has been crippled by lack of shipping. Thus, the outstanding note in the utilization of coal this year is not the development of new methods of burning or handling coal but the extraordinary job that the industry has done in producing enough coal to serve all needs.

Jan 1, 1943

By R. A. Haney, S. J. Gigliotti

Over the past ten years, analysis of the acceptability of face ventilation systems has been based on numerical criteria rather than solely a study of air flow and methane patterns in the face area. This type of analysis has become possible primarily because of the instrumentation and mathematical models developed by the Ventilation Division, Pittsburgh Health Technology Center, Mine Safety and Health Administration (MSHA). To properly use these mathematical models, large amounts of methane and airflow data must be collected in the face area during mining activities. To supplement underground testing of face ventilation systems, a full scale model of a face area was built. This model includes a full scale model continuous miner, a face ventilation system, a gas release system, and a remote methane detection system. The remote methane detection system consists of an array of twelve methane sensors located throughout the face area. Data from the sensors are transmitted to strip chart recorders. Methane, air quantity, and other data collected during a test are entered into a computer for analysis. This paper presents the data entry system, the models used for data analysis, the test results, and the application of these results to a face ventilation system.

Jan 1, 1983

Jan 1, 1883

By AIME AIME

THE annual meeting of the A.I.M.E. was fittingly closed with a joint meeting of the Metropolitan sections of the four National societies on Feb. 18, at which this subject was adequately discussed by leading engineers before an audience that completely filled the Engineering Auditorium. The large amount of publicity that has been given the Diesel electric loco- motive, and the often garbled reports of its performance and possibilities that have been circulated, makes it particularly fitting that the facts should be given the profession as determined by those who have aided in developing and operating this latest form of prime- mover in railroad operation. C. A. Stein, general manager of the Central R. R. of New Jersey, opened the meeting with a discussion of the problem of electrification, and the relation of the short haul, switching, and terminal service to heavy electrification. Referring directly to the problem of the Central R. R. of New Jersey, some subtitution for the steam locomotive is necessary within the city limits of New York because of local ordinances against the smoke nuisance. While the improvement in the design of the steam locomotive has been marked-the efiiency today is over fifty times that of the locomotive of 100 years ago-it has now probably reached the point of maximum perfection. If anything, it is open to the criticism of having Coo many appliances to get out of

Jan 1, 1926

By HOWARD N. EAVENS

DURING the year just closed the bituminous industry has been marked by a continuation of the period of low prices and a steady deflation, accompanied by the closing of mines and the consolidation of small units into larger ones. This pro- gram has marked almost every field in the country, and it bids fair to continue for some time. Some figures recently published for Kentucky show that in 1924 there were 660 mines producing 45,147,000 tons; in 1928 the number had decreased to 537, while production had increased to 61,860,000 tons, and a similar movement is occurring all over the country. Prices throughout the early part of the year were very low, but during the fall and winter the prices received are more satisfactory than they were earlier in the year. One of the leading developments in the marketing of coal during the year was the trade practice movement, which began in the Harlan field, and has now been adopted in the Harlan, Hazard, Appalachian, Logan. Williamson and Kanawha fields. The purpose of this movement is to prevent the shipment of coal except on order, and by the publication of price lists to prevent much senseless price quotation. Where it has been practised the longest this movement has resulted in a considerable degree of stabilization, and, undoubtedly, it will help existing conditions very materially if it becomes universal.

Jan 1, 1930

AUGUST began with a reminder that warfare was still in progress in the world, in that the Greeks, still at war with Turkey, threatened Constantinople in spite of the small British and French forces of occupation and opened a vista of international dangers. There was in this, moreover, a recollection that religious questions in India had prevented the British from permitting a real settlement of the Turkish question, wherein the absence of Russia as a great power is missed. Civil warfare also continued in Ireland and China. Even in the military way the world is far from being at peace. Bloody fighting between the Fascisti (anti-communists) and the com-munists in Italy led to several provinces being put under martial law, but after a while these disturbances were quelled. In the latter part of the month the assassination of Michael Collins in Ireland produced a great shock. From China, however, there came rather favorable news, indicating the early reintegration of that country, which sooner or later ought to play an important part in world affairs. Economically, instead of there being any improve-ment, there grew a clearer perception of how bad things really are. Italian politics were in chaos through inability to find anyone to accept the premiership and assume the all but hopeless task of averting national bankruptcy. The French, too, began to see their own position in true colors, and especially to see how in reconstruction they had incurred debts on the strength of what they hoped to collect from Germany, with at last the understanding that the Germans could not pay and that France herself was thereby put in a desper-ate economic position. As for the Germans, them-selves their Reichsbank defaulted on ordinary bills early in August. As the month wore on the value of marks fell more and more and at the end it appeared that Germany was on the verge of economic collapse. On Aug. 7, another international conference (with America again absent) was assembled in London, this being the thirteenth since the war, and there was a general feeling that it would be the last. The prime question was what is to be done about the German reparations, but underlying was the whole subject of the entente. The conference opened like a meeting of importunate creditors, doubtful whether the debtor had any tangible assets. On Aug. 14 this conference broke up without coming to any useful conclusion. Indeed, the acrimony among the premiers was so sharp that even the entente between Great Britain and France was endangered. The international situation was saved only by the Reparations Commission excusing the Germans from the payment of 50,000,000 gold marks that come due on Aug. 15 But although the entente was nominally preserved there is no longer any illusion about the interests of Great Britain and France being different and that henceforth they will play their own hands. The London conference was really an effort to maintain the partnership, and it failed.

Jan 9, 1922

By E. W. Newman

DURING 1943 and 1944, there was an urgent need for certain grades of optical calcite (Iceland spar) for instruments for military uses. To find a supply of this material, prospecting was carried out in Montana, California and Colorado. Although some production was obtained by the work in California, the best results were from prospecting the large calcite veins of south central Montana. The bulk of the optical calcite mined during World War II has come from that area. The Bureau of Mines took an active part in the search for optical calcite in Montana. It examined most of the known calcite veins in the 70-mile distance between Wilsall, on the Shields River, and Absarokee, on the Stillwater River, and conducted exploration on several of the deposits. The Geological Survey also took an active part by mapping many of the veins. Actual mining of the calcite was performed at first by Calcite Operators, Inc., and later by the Metals Reserve Co., through an agent. A sorting plant was established at Clyde Park, where custom material could be sold. These activities stimulated mining by private operators. To be suitable for military uses, the calcite mined had to meet rigid specifications as to both size and quality. Individual crystals had to be clear and transparent and if in the form of rhombs had to measure at least 7/8 in. on each edge. Some color and a few inclusions in the calcite were allowable, but material with incipient or developed cleavages, or showing twinning other than parallel to the base, was unacceptable. HISTORY OF DEPOSITS The existence of large veins of calcite in south central Montana has long been known, and for many years the farmers of this region have used the common vein calcite for producing grit for chicken feed. According to reports, the first optical calcite produced from Montana came from the Cartwright deposit near Greycliff,1 but until recently the mining of optical calcite in Montana has been limited to spasmodic searching for small crystals suitable for making nicol prisms for saccharimeters and microscopes, or for mineral specimens. The possible need of substantial amounts of optical calcite for military uses began to appear late in 1942 and early in 1943, therefore the Polaroid company began searching for a source of supply in Montana and California. Work on the Wade property near Clyde Park was started on a small scale in the fall of 1942, by A. H. Hansen, of Clyde Park. During the winter and spring of 1943, a modest quantity of optical calcite was mined and shipped to the Polaroid Corporation, Cambridge, Mass. Most of this was produced from the "Hansen vug," which was found close to the surface. Early in the summer of 1943, mining on the Wade property was undertaken by Calcite Operators, Inc., a company organized for mining optical calcite from the Montana and California deposits. This com-

Jan 1, 1945