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By ALEX. S. THOMAS

HOWEVER good a furnace may be in regard to design, etc., or however excellent in the quality of the gas used, a suitable heat for the successful working of the metal cannot be obtained unless the melt be coated with a proper quantity of slag. This coating may be excessive or it may be deficient in quantity. The right degree of heat is the essential condition of successful working, for the quality of the steel made is never very good when the metal is allowed to simmer in the furnace for an excessive period, and this heat cannot be obtained if the metal is not protected by a proper covering of slag. This is not only to prevent the metal being over-oxidized and wasted, but also to prevent the metal being chilled when exposed with only a thin covering of slag. The slag may be obtained in either of two ways : 1, naturally, by the presence of sufficient silicon in the iron used, to unite with iron oxide to form a staple slag ; or, 2, by the addition of slag or free silica. In the first case the slag is formed naturally by the action of the oxygen in the flame - i.e., the oxidizing atmosphere of the furnace-on the silicon in the metal when melting. The charge then melts, as it is termed, "thick," and protects the banks from being cut. If too much silicon be present, however, and an excessive quantity of slag be formed, it will be found to be rather infusible, and unless care be taken to add the oxides quickly and follow the furnace up-thus rendering the slag more fusible by the extra iron oxide-the furnace bottom is liable to be pulled up. In such cases the author has frequently been able to warn

Nov 1, 1906

By C. F. Jenkins, G. V. Smith

Serrated plastic flow in stable austenitic alloys based on Fe/Ni has been shown to be related to the presence of carbon and/or chromium in the systems. Strength peaks and plateaus in the serrated-flow temperature region for a commercial alloy correlate with an increased dislocation content, arising, presumably, from enhanced multiplication as a result of a strong interaction between dislocations and solute atoms. The data generally support a mechanism controlled by migration of vacancies, with the energy for vacancy motion being modified by the presence of chromium. Chromium atom -dislocation interaction is responsible for effects above 500°C, whereas the defect interacting with dislocations between 200" and 500°C is suggested to be a carbon-vacancy Pair. ThE phenomenon of jerky flow, serrated flow, or the Portevin-le Chatelier (P-C) effect in austenitic stainless steels is usually attributed to substitutional at1,2 mospheres1,2 or to precipitates&apos;-4 which form at dislocations during plastic deformation. On the other hand, evidence exists which supports a direct inter-stitial-dislocation interaction mechanism for serrated flow in fcc Ni-C,5,6 Ni-H7-9 and in nickel-austenites containing carbon." The present work consists in a study of serrated plastic flow in stable austenitic al-loys. The effects of carbon and of chromium were investigated separately, and a commercial stainless steel with different levels of interstitial impurity concentration was studied in an attempt to delineate the combined effects of the alloying elements. EXPERIMENTAL TECHNIQUES a) Materials and Fabrication. A commercial AISI 330 stainless steel and several specially prepared aus-tenitic alloys have been studied. The experimental alloys were prepared by arc melting the constituents under purified argon. Analyses of the materials are given in Table I. The commercial alloy was obtained as 5/8 in. bar stock and rolled to 0.092 in. sq, with several intermediate anneals. At this stage some of the material was annealed in Pd-purified hydrogen at 1100°C to establish different levels of interstitial content. All other heat treatments were in vacuum (10-5 torr). The "pure" alloy ingots were swaged to 0.120-in. rod and annealed in Pd-purified hydrogen at 1100°C. The analyses for these conditions are also contained in Table I. Following the above treatment, the final wire sizes Table I. Chemical Analyses of Test Materials Hrin Hydrogen at Cr, Ni, Alloy 1lOO°C wt pct wt pct C, ppm* N, ppm* Type 330 As-received 14.78 33.25 430 300 Type 330 64 14.78 33.25 40 50 Type 330 200 14.78 33.25 27 21 Fe/35 Ni 72 - 35.10 <10 62 Fe/35 Ni 200 35.10 <I0 44 Fe/35 Nil15 Cr 72 14.95 34.94 <I0 61 Fe/35 Ni/15Cr 200 14.95 34.94 <10 45 Fe/35 Ni/C $ 35.OM 380 *Sensitivity: N t 5 ppm Ct10ppm. f Nominal Ni content. % A master NiC alloy was used in preparation of this material; courtesy of D.E. Sonon. were obtained by either swaging or cold drawing. The test results did not vary with these techniques. b) Specimen Preparation. Two sizes of specimen and two gripping systems were used. i) 0.070-in. wire with a chemically milled gage section: 0.75 in. long, 0.060 in. in diam. These were fastened into grips containing tapped grooves. ii) 0.050 in. wire, gage length 1.5 in. Ball bearings were welded to the ends of the wires and the gage length was taken to include all material between the welds. Socket-type grips were used with these specimens. With specimens of type ii), joining was performed in a specially constructed brass jig, under argon, and automatic timing was utilized in the procedure. No adverse effects of welding were noted. Specimens were encapsulated and solution treated for 1 hr at temperatures selected to produce the same average grain size, -50 µ. Annealing twin boundaries as well as normal crystal boundaries were counted. The temperatures used are listed in Table 11. Table 11. Specimen Size. Temperature of Heat Treatment and Resulting Grain Diameters for Test Materials Recrystallization Resulting Material Condition Temperature Grain Sue AISI 330 Not H purified 0.070 120O°C 45 to 55µ in, wire AlSl 330 H , pure, 0.070 in. 1150°C 45to55µ wire Fc/35Nil15Cr Pure, 0.070 in. wire 1000°C 45tossp Fe/Ni Pure. 0.070 in. wire 775°C 45 to 55µ Fe/Ni/C Pure, 0.050 in. wire 850°C 10 to 20p AlSl 330 Not purified, 0.050 1150CC 45to55p in. wire AlSl 330 ti, pure, 0.050 in. 1150°C 45to55p wire

Jan 1, 1970

By James P. Roe

I. INTRODUCTION. THOSE who deem the subject of this paper an old and super¬seded one may recall with advantage the words of the great proverb-maker, bidding us to seek the new in the ashes of the old. The manufacture of wrought-iron began with the small hearth built upon an eminence, and relying on the wind for blast. Next came, either the hearth about 12 in. in diameter by 2 ft. in height, blown by a man operating two goat-skins for bellows, or, a hearth of greatly varying diameter and about 10 ft. high, depending for its blast upon natural draft. The former appeared in India, the latter in Burmah; and both were in operation until quite recently, though their origin is lost in prehistoric times. The Catalan forge was the evolutionary descendant of the foregoing, and the parent of the Blase-ofen, which in turn led to the high bloomary or " Stückofen," the father of the blast-furnace, as a producer of cast-iron. The production of cast-iron checked the growth of the direct processes; and led to the introduction of various hearths, such as the Walloon, for low-silicon irons; and the South Wales process, combining the run-out fire with the finery, for higher-silicon irons. Some of these are still in operation in localities possessing the necessary raw materials; and their product is used for purposes requiring wrought-iron of exceptional quality, the supply of which is still smaller than the demand. We have to look back but a century and a quarter to see the introduction of the puddling process by Henry Cort; a process which, reinforced by the iron-oxide bottoms and fettling of Hall, was not less revolutionary in character, and more revo-

Jul 1, 1905

By N. R. MacMillan

INTRODUCTION The Bullmoose Coal Project is part of a major development in northeastern British Columbia which comprises a new rail line, a new townsite, powerline, highway, the upgrading of the Canadian National Railway&apos;s main line, a new coal port at Prince Rupert and two new coal mines, the Bullmoose mine and the Quintette mine. The total investment by all parties is estimated to be in excess of $2.6 billion and made up approximately as follows : [Table No. 1 $ Millions - Quintette Coal Limited 950 Teck-Bullmoose Coal Inc. 275 Canadian National Railway Company 800 6 British Columbia Railway Company Port at Prince Rupert 280 Townsite, Roads 6- Power ] The new infrastructure is intended to serve not only the Bullmoose and Quintette coal projects but also eventually a number of other coal properties in northeastern British Columbia. The Bullmoose project is structured on a joint venture basis as follows : [Table No. 2 Teck Corporation 51% Lornex Mining Corporation Ltd. 39% Nissho Iwai Coal Development 1 0% (Canada) Ltd. -- 100% ] The mine has a capacity of 2.3 million tonnes of clean coal per year. In the initial years 1.7 million tonnes will be metallurgical coal and 0.6 million tonnes thermal coal. After the first three years of operations the annual production of metallurgical coal will increase to an average of approximately 2.1 million tonnes and the production of thermal coal will decrease to an average of approximately 0.2 million tonnes. At this level of 2.3 million tonnes annual production, the Bullmoose mine has sufficient reserves for at least 26 years of production. History Brameda Resources Ltd. commenced coal exploration in the Bullmoose-Sukunka area in 1969. Teck obtained an option on the Bullmoose coal licences in 1970 and started surface exploration and diamond drilling in 1971. Teck earned a 50% interest in the property, and thereafter expenses were jointly financed by Teck and Brameda. In 1981 Brameda merged with Teck making Teck the sole owner. The initial phase of the exploration program, which was completed in 1975, included 7,200 meters of diamond drilling in 35 holes. During 1976 and 1977, detailed exploration and test work were carried out on the South Fork and West Fork areas where multiple seams close to surfaces indicated the potential for large tonnages of strippable coal. In those two years, work included road construction, detailed mapping and trenching to outline the coal seam traces at the surface, 6,300 meters of diamond drilling in 80 holes, and 300 meters of underground bulk sampling from seven adits. Washability tests and analysis work were carried out on the drill cores and adit samples, and pilot plant washability studies were undertaken. In 1978 and 1979 Teck engineers prepared open pit mining plans and production schedules and Kaiser Engineering was retained to prepare a layout of the plant preparation facility. A feasibility study prepared by Teck&apos;s engineering group in January 1982 was the base document used by the Lenders in assessing the technical and economic viability of the project. Property Location The property lies some 650 kilometers northeast of Vancouver, and 87 kilometers south by road from the village of Chetwynd. The Sukunka property (British Petroleum) adjoins to the north, the Mount Spieker property (Ranger Oil Option) adjoins to the east, and the Quintette property is located to the southeast.

Jan 1, 1985

Abadilla, Quirico A., Geol.. Lago Pet. Corp Box 172 Maracaiho, Venezuela. IIAbbw. Robert Graham. The W. W. Sly Mfg. Co.Train Ave.. Cleveland. Ohio. Abbotf A. N., Mines Supt., Maznpil Copper Co.. Ltd..Conception del Oro, Zac., Mexico. Abbotf Clarence E, Mgr.. Mines & Quarries, Tenn. Coal. Iron & R. R. Co., 1242 Brown Marx Bldg., Birmingham, Ala. Abbott. Louis Benjamin. Chief Engr.. Consolidation Coal Co. ... .Elkhorn Div., Jenkins, Ky. Abeel, George 8.. Jr., Cons. Min. Engr...4612 West 17th St., Los Angeles, Cal. Abel. Albert E.. Asst. to Pres.. Valley Mould & Iron Corp..Hubbard, Ohio. Abel. Raymond L Asst. Prof., Dept. of Pet. Refin.. Univ. of Pittsburgh. .. .Pittsburgh. Pa. Abernathy. George Elmer. Prof. of Geol. & Min.. Kansas State Teachers College. Pittahurg. Kans. Abernethy, D. Carl, Jr. Min. Engr., Hudson Coal Co. .Scranton, Pa. Abw, Hirouhi. Min. & Met. Engr., Min. & Met. Dept., The Higher Technical School, Osaka, Japan. Aborn. Robert H.. Research Assoc.. Mass. Inst. of Tech..Cambridge, Mass. Abouchar. Bylvain Sley. Min. Engr. & Geol., c/o S. H. Sekaly, 13 Rue El Nimr, Cairo, Egypt. tAbozeid. Mahmood. Pet. Min. Engr., Marland Oil Co. of California, Subway Terminal Bldg., Los Angeles, Cal. Abraham. Arthur W.A. pt. 40, Barcelona. Anzoatmui, Venezuela. Abrahams. Alexander I.. Gen&apos;l Mgr., Racon Electrical Co.. ..... .Slough, London, England. tAbrahamuon, C. W., Min. Engr.. The Mond Nickel Co., Ltd.. ..... .Levack. Ont., Canada. Abstein, Henry T.. Engr. & Mgr.. Profile-Tamarack Mines Co.. ...... .Yellow Pine, Idaho. tAcker, E. WC.. Met.. ........ .I28 East Washington Lane. Germantuwn. Philadelphia, Pa. IlAckerman, D. E.. Research Engr.. Research Lab., International Nickel Co., Bayonne, N. J. tAckerman. Ernest R., Pres., Lawrence Portland Cement Co.. . .Plainfield, Union Co., N. J. Adachi. Jinzoo.A..d dress Wanted Adachi, Yuichi, Chief Engr.. Anzan Steel Works, South Manchuria RY. Co., Anzan, South Manchuria. China. (Via Dairen). Adair, Arthur C, Valuation Engr., Internal Revenue. Treasury Dept.. . .Washington, D. C. Adami. Arthur E., Prof. of Min. Engrg., Montana State School of Mines. Butte, Mont. Adami. Charles J.. Min. Engr., Gen&apos;l Mnr., St. Jos~ph Lead Co.. ....... .Bonne Terre, Mo. Adama, C. W., Pres. Adams Pacific Corp .I66 Montgomery St., San Francisco. Cal. Adams. Cuyler .Dee rwood, Minn. Adams, David T, 514 Wrigley Bldg.. Chicago, Ill. ADAMS, FRANK DAWSON, Logan Prof. of Geology and Dean, Faculty of Applied Science. McGiU Univ., Montreal. Que.. Canada. Adams. Gale L, Research Engr.. General Pet. Corp...Los Angeles. Cal. Adams. George I.. Prof. of Geol. & Mineralogy. Univ. of Alabama. .Tuscalmsa, Ala. Adams. H. H.. Cons. Gml..Room 415, W. T. Waggoner Bldg., Fort Worth. Tex. Adams, Henry, Cons. Min. Engr. . 934 Park Ave., Plainfield, N. J. Adame, Henry H. 285 Madison Ave., New York. N. Y. Adams. Henry Farnum. Engr.. Charge Experimental Work, Inspiration Concentrator. Inspiration Cons. Copper Co.. Box 364, Inspiration. Ariz. Adams, Huntington, Min. Engr, 149 Broadway, New York, N. Y. Adams. Leland D, V.P.. Leslie-California Salt Co., 166 Montgomery St.. San Francisco. Cal. Adams. Louie W.. Illinois Steel Co Gary, Ind. Adama, XL L. Min. Engr.. Old Ben Coal Corp., Mine 12.. Christopher. IU. Adams, Robert M. Robert M. Adam Co. .I201 Fidelity Bldg., Duluth, Minn. Adams. Sidney F.. Geol., Empire Zinc Co .Gilman, Colo. tAdams, Waldo Peck..P ittsfield, Pike Co.. Ill. Addams. Charles 1. Min. Engr.. Bo x 663. Phoenix, Ariz. Addicka, Lawrence. Cons. Enar..... .61 Maiden Lane. New York. N. Y. Addison, Herbert, V.P.. Big Horn Collieries Co ,412 Colorado Bldg., Denver, Colo. Adkemn. J. Carson. Min. Engr.. HY Grade Manganese Co., Inc..Woodstock, Va. Ady. Joseph Wesley. Jr.. Min. Enar., 314 Mining Exchange Blda., Colorado Springs, Colo. Affelder. William Lewis. Asst. to Pres., Hillman Coal & Coke Co. & Allied Companies. 2006 First National Bank Bldg.. Pittshurgh, Pa. Ameck, B. F.. Pres.. Universal Portland Cement Co. .. .210 South La Salle St., Chicago. Ill. Agabeg, Edgar C.. Cons. Min. Engr.. ..... .Evelyn Lodae. Asansol, E. I. R. Bengal, India. tAsar. William M.. Aest. Prof. of Geol.. Kirtland Hall, Yale Univ.. ... .New Haven, Conn. Agaeniz. Rodolphe L, Pres.. Calumet & Hecla Consolidated Copper Co. ...... .Boston, Mass. tAgens, William Holmes. District Mgr.. Traylor Engrg. & Mfg. Co., 362 I. W. Hellman Blda.. Los Aneeles. Cal.

Jan 1, 1928

By H. W. Becker, C. C. Frye, A. V. Degau, A. Masuda

Natural gas containing 25.65 per cent hydrogen sulfide and 4.75 per cent carbon dioxicle is gathered frorn eight \veih arid tratzsporrcd 26 miles at a flow rate of 160 MMcf/D and at operating pressures of frotrl 1,200 to 1,800 psig. Dry desiccant dehydrators at each wellsite tnaintaitz the dew point of the gas below 17F. Telemetering facililies permit control of field operations from a central instrunlent console. Corrosion control ineasures, design coilsiderations and material specifications pertainitz to these specia1 conditions are cliscussed. INTRODUCTION Natural gas containing 25.65 per cent H2S and 4.75 pcr cent CO, is produced from the Pine Creek field, Alta. It is dehydrated at wellheads, gathered at 2.200 psig and transported 26 miles to the Windfall field where it is delivered to the inlet of injection compressors at 1,800 psig. The daily average volume of gas transported is 160 MMcf. The project is believed to be unique in its combination of percentage of hydrogen sulfide, operating pressure and transportation distance. This paper describes the project and presents details of some of the design features, corrosion control program and centralized automatic operational control. The Pine Creek field project is one phase of a joint operation of two fields—thc other being the Windfall field. The two fields lie about 30 miles north of Edson, Alta. and 20 miles west of Whitecourt, Alta., respectively, as shown on the map (Fig. 1). They are owned by the same interests and operated according to a plan for maximum economic recovery of products. The Windfall Leduc D-3 reservoir contains a rich condensate-bearing gas containing 15.5 per cent HIS. The gas from the Pine Creek field contains only very small quantities of butane and heavier products. The Windfall reservoir is being cycled to obtain maximum condensate recovery using gas from the Pine Creek field as the displacing fluid, while producing the residue sales gas for both fields from the Windfall field. The Pine Creek field development and gas-gathering facilities are shown on the map (Fig. 2). The producing formation is the Leduc D-3 reef at a depth of 11,300 ft. The original reservoir pressure was 4,590 psia at 7,400 ft subsea and the temperature is 245F. Eight wells are equippcd with dry desiccant dehydrators with the following capacity ratings: three at 35 MMcf/D; three at 20 MMcf/D; and two at 10 MMcf/D. WELLHEAD EQUIPMENT Dry desiccant dehydrators were designed to reduce the water content of the saturated wellhead stream to 2.5 lb of water/MMcf at 2,000 psig. This specification was necessary to prevent hydrates and corrosion forming in the pipeline which will operate at temperatures as low as 20F. A typical flow diagram is shown in Fig. 3, and Fig. 4 is a photograph of one of the wellhead installations. Some of the design details given below are subject to modification in the field. The well-stream flowing temperatures range from 135 to 170F. Wellhead flowing pressures up to 3,200 psig are reduced to the dehydrator-operating pressure of about 2,100 psig by throttling through a pressure control valve. The gas is then passed through an aerial cooler where its temperature is reduced to 105F. thus removing over half

By J. L. Perry

FOR many years, you and your fellow members of the American Institute of Mining and Metallurgical Engineers have devotedly and ably applied yourselves to the art of making iron and steel. having foremost in your minds the conservation of raw materials, suitable and efficient facilities, economical processes, and improved quality of product. For the past three strenuous years you have contributed wholeheartedly to meeting the problems of increased production. You have conducted scientific and technical investigations and research, recommended experiments. and gathered all the available and valuable information possible to gain the desired objectives. You have had many obstacles and difficulties to overcome. In the early days of your organization, there was some lack of co-operation from the industry itself-perhaps, for example, some failure to recognize the mutual advantages of free exchange of experiences and information. But regardless of any hindrances, you have made many and valuable contribution which have tended to make iron and steel manufacture leas of an art and more of a science.

Jan 1, 1944

By Frederick G. Tickell

GEOLOGISTS have been quick to adopt new methods in locating new oil fields and in finding the extensions, laterally or at depth, of the old fields. For most of these new methods he is indebted to the physicist, the engineer, and the chemist, although he has also drawn from such ordinarily unrelated sciences as bacteriology and protozoölogy. These last-named sciences have been of help in problems dealing with the origin of petroleum and, although not of direct application to oil finding, have furnished evidence of value in learning what oil is made from and what are the natural agencies involved in its formation.

Jan 1, 1932

By Fred D. Gustafson

With the postwar emergency for new housing and for new industrial buildings, much research has been done on lightweight aggregates for use in concrete and plaster. The trend toward lighter weight aggregates to relieve the dead load on the higher, steel frame- work buildings started toward the end of the last century. Progressively the requirements be- came more stringent, crushed bank slag, weighing 80 lb per cu ft as com- pared to 100 lb for crushed rock, was supplemented in some sections by foamed slags and expanded shales weighing from 40 to 60 lb per cu ft. In other sections cinders were used weighing from 40 to 50 lb, including sand. Sections favored with more recent vulcanism turned to pumice weighing from 30 to 60 lb, whereas other localities made use of diatomite, from 28 to 40 lb. Exfoliated vermiculite weighing from only 6 to 10 lb per cu ft came into use. As the search for lighter weights in aggregates continued so did the search for other desirable properties such as nailability, ease of cutting or channeling, and good insulation to both sound and heat. This search eventually led to a widespread interest in the expansion of perlite, or similar volcanic glasses, with the result that in 1946, the Office of the Housing Expediter&apos; listed eleven firms reporting the operation of processing plants either on pilot or commercial scale producing aggregates weighing from 2 to 16 lb per cu ft.

Jan 1, 1949

By H. R. Stahl

FIVE mills are operated in Southeast Missouri by the St. Joseph Lead Co.; these have a total rated capacity of 24,300 tons per day divided as follows: Federal, 12,000 tons; Leadwood, 4800 tons; Desloge, 3600 tons; Bonne Terre, 2400 tons; and Mine La Motte, 1500 tons. These concentrators are similar in a general way, differing mainly in size and type of equipment and in minor variations in flow sheet. No attempt is made rigidly to standardize procedure in the various mills in spite of a general similarity in the ores. Each mill may be regarded as a separate laboratory in which new ideas and changes may be tried. A generalized description of the process is given, noting important differences in procedure at the various plants. The concentration process may be divided into five main stages: dry crushing, wet grinding, desliming and classification, tabling, and flotation.

Jan 1, 1947

By F. C. Smyers, E. W. Merrick

ALTHOUGH the zinc and pyrite concentrates produced at Midvale go to other companies, the United States Smelting Refining and Mining Company smelts and refines its own lead. Refining is the first step of the process that is done at some distance from the mining operations, the plant being at East Chicago, Ind., an industrial center about 25 miles southeast of Chicago. For years it has been notable as being the only lead refinery in the country using the Betts electrolytic process. The original buildings, many of which are still in use, were erected in 1906 when the plant was known as the United States Metals Refining Co. In 1920 the parent company sold its copper refinery at Chrome, N. J., and since the copper refinery was also known as the U. S.

Jan 1, 1948

By Frederic P. Dewey

This old and well-known method of determining silver is, in bullion work, so far superior to the furnace-assay that it is looked upon with reverential awe by many, if not by most, users, and its ease of execution, with proper equipment, commends it highly where much commercial bullion work on silver is required. The method is so thoroughly well known that a description of it here may seem to be unnecessary, but many thousands of determinations are annually made by it in the U. S. Mint Service and its practice is there reduced to an art. This is necessary both for the sake of economy of time, and because high-grade work with it requires constant practice. It is useless for a person who uses it only occasionally to expect to attain high accuracy with it, without spending more time upon a detemination than is warranted in a busy commercial laboratory. It is always employed in the Mint service whenever possible, but its chief field is in the determination of silver in standard silver (ingots and coin), which is 900 fine in silver and 100 fine in copper, and I shall first briefly outline its use on this metal and then take up various points in detail, especially as related to the accuracy of the results obtained. For this determination 1,115 mg. of standard metal are weighed and transferred to a glass-stoppered bottle, the metal is dissolved in nitric acid, and 100 cc. of a standard solution of NaCl run in. The bottle is then vigorously shaken and a measured portion of a decimal salt solution added, and again shaken, if necessary. These operations are repeated until the silver is precipitated. Standard metal being 900 fine, 1,115 mg. should carry 1,003.5 mg. of silver, which is a convenient figure to work with.

Jan 1, 1914

By Ta M. Li

How do you convert a copper-zinc resource into a viable economic mining operation? This problem, unlike most, was complicated by the additional presence of a sub-arctic climate, highest labor costs in the world, low-grade copper-zinc values, depressed market prices, and a complex mineralization.

Jan 12, 1977

By Eugene McAuliffe

NO physical impairment can be more serious than the partial or complete loss of sight. With reasonably good eyesight, a person is equipped to care for life and I limb, provided a rational measure of t caution is manifested. When the sight of one eye is lost or badly impaired, one-half of this God-given asset is gone, and extreme care must be taken to prevent the tragedy of total darkness that closes out the beauty of sky, field and mountain, the faces of relatives and friends, and either removes entirely or in part one&apos;s capacity to produce and earn. During 1933, The Union Pacific Coal Co., operating ten coal mines in Wyoming, decided to undertake a visual survey of all of its mine operating officials and employees. Although the cost of workmen&apos;s compensation paid because of eye injuries was material, the management was more deeply concerned with the social loss and the suffering resulting from the many eye injuries. As every element of coal production cost must be scrutinized, accurate data on all accidents, with the workmen&apos;s compensation paid therefor, are carried forward monthly. The number of accidents to eyesight and the resultant compensation paid are shown in Table 1 for nine calendar years:

Jan 1, 1934

By James H. Bechtold

The yield strength of annealed tungsten was found to have a strain rate exponent 12 times as great as that of low carbon steel. The effects of temperature and strain rate could be correlated through the Zener-Hollomon parameter with a heat of activation associated with yielding of 32,000 cal per g-atom. This heat of activation is independent of strain although both the temperature and strain rate dependence of the yield strength vary with strain. MOST metals have mechanical properties that are relatively insensitive to strain rate, especially at temperatures below that at which creep is important. In iron and molybdenum," however, relatively large strain rate effects are observed in the temperature range where the rapid increase in yield strength occurs which leads to the ductile to brittle transition. In this temperature range Zener and Hollomon&apos; have suggested that the effects of strain rate and temperature T on the yield strength could be correlated through a single parameter, P, in the following manner where Q is a heat of activation characteristic of the metal and associated with some unspecified relaxation process. They also observed that if the temperature is restricted to a relatively narrow range— below room temperature for steel—that the logarithm of the yield strength could be expressed as a linear function of the logarithm of P. From this relation the logarithm of stress should be a linear function of the logarithm of the strain rate at constant temperature: where r will be referred to herein as the strain rate exponent. At a constant strain rate the logarithm of stress should be a linear function of l/T, ay(e = C) ~ eT [4] where q = Qr [5] and is referred to herein as the temperature exponent. These equations have been found to relate the effects of temperature and strain rate on the yield strength of molybdenum in the temperature range wherein the ductile to brittle transition occurs, —75° to +150°C.2 Bechtold and Shewmon3 have shown recently that the ductile to brittle transition in annealed tungsten occurs in the temperature range +150° to +350°C. In this temperature range the yield strength in-

Jan 1, 1957

By R. J. Woody

DESIGN of the most economic continuous counter-current decantation (CCD) circuit is based on selection of the number of stages and the wash volume that will give the minimum summation of the following items: 1) Capital and operating costs of the CCD circuit. 2) Capital and operating costs of the precipitation circuit. 3) Value of the dissolved product lost.

Jan 7, 1958

By F. Twyman, D. M. Smith

THOSE chemists (they are still greatly in the minority) who use the spectroscope, use it very often, and find it almost indispensable. As a means of detecting minute quantities of the metals it is unrivalled. A metal can be readily distinguished in the presence of any other element, compound, or mixture without the necessity of separation. The qualitative analysis of the metallic constituents of a substance, which the spectroscope gives so easily, is a sure basis for planning a chemical analysis. As the determination of each element proceeds the purity of precipitates may be checked as often as desired. If, possessing these advantages, the spectroscope has been neglected in general chemistry, it is not surprising that it was neglected in metallurgical chemistry; for many of the impurities which are of industrial interest, even when they are present in a metal or alloy in small quantities, are not then always easily detected by the examination of their visible spectrum. The history of the development of the art has been given in Bureau of Standards Scientific Paper No. 444.

Jan 1, 1928

By J. C. Bradley

THE relation of annealing temperature to conductivity of copper wire has been determined. Conductivity hard was 98.26 per cent. After a 10-min. heating at 200°C. it was 98.69. By annealing 10 min. at 300° C. a large increase, to 100.93, occurred. Maximum conductivity, 101.15, was attained after a 500° C. anneal; thereafter it decreased to 100.53 after a 950° C. anneal. If copper is gassed the decrease is much more than this. Materials and Methods The work was done on high grade electrolytic copper, 99.942 per cent. copper plus silver, silver 0.0008 per cent. It was hot-rolled to >/4 in., then cold drawn to 0.080 in. The wire was cut into 25 5-ft. lengths and numbered 1 to 25 as cut. Four samples were tested hard. The others were wound into 5-in. diameter coils. For the 100° C. heating a coil was put into water, the water brought to boiling, and the wire kept at this temperature for 10 min. For the higher temperatures the coils were placed in envelopes of sheet copper, a little water added, and the envelopes sealed by folding over the edges twice, and hammering them together. This kept the air out very well. The envelope and wire &apos;were brought to the desired temperature; this was maintained for 10 min., then the whole was water-quenched.

Jan 1, 1927

By DOOLITTLE E. M.

(Canal Zone Meeting, November, 1910.) The following notes are contributed, not with the idea of offering a complete history of the development of this very important process as applied to the Leadville district, but with the hope that the practice, as it was carried out in the Bi-Metallic Smelter, may still be of interest to others. The Bi-Metallic Smelter, at Leadville, Colo., was the first to make a commercial success of the process described in the following pages, which consisted essentially of smelting raw silver- and copper-bearing sulphide ores in blast-furnaces to form a matte, which was generally re-smelted with siliceous ores for a second high-grade matte. Robert Sticht, in his excellent monograph on the subject,1 has outlined briefly the plant belonging to this company. He says, in effect: The Boulder, Mont., enterprise set the example for others with whom the patentee (w. L. Austin) had been negotiating, and the old La Plata lead-smelter at Leadville, Colo., was fashioned into a crude, temporary experimental plant for the Bi-Metallic Company, and the feasibility of the process demonstrated by a trial run. Subsequently, the plant was considerably improved, and, being supplied with very favorable ores, continued to run without interruption from August, 1892, to June, 1893. In September, 1893, smelting was resumed in a completely remodeled establishment, some $200,000 having been expended upon the new work. Thus, aside from the Montana experiments, which, under the direction of W. L. Austin, began as early as- 1885 2 at Toston, and continued with indifferent success for six or seven years, the Bi-Metallic plant at Leadville may be said to have * Formerly Superintendent, Bi-Metallic Smelting Co. + Formerly Chief Assayer and Chemist, Bi-Metallic Smelting Co. 1 Modern Copper Smelting, E. D. Peters, 7th ed., p. 415 (1895). 2 Trans., xvi., p. 259 (1887-88).

Dec 1, 1910

By John M. Kelly

New Mexico produced 39,751,868 bbl. of oil in 1941 and ranked seventh among the oil-producing states. Its 1941 production established an annual record, exceeding the 1940 record year by 854,498 bbl. The average daily production for the year was 108,909 bbl. The average daily non-marginal well allowable for New Mexico on Jan. I, 1941, was 36 bbl.; at the close of the year it was 43 bbl. The average daily pipe-linc runs were approximately 3 per cent less than the allocations of the New Mexico Oil Conservation Commission, which followed closely the recommendation of the United States Bureau of Mines in setting the daily outlet demand. The production in Lea County was 34,333,448 bbl.; Eddy County, 5,009,354 bbl.; and northwestern New Mexico (San Juan and McKinley Counties), 406,306 barrels. The total number of completions in the state was 402, of which 301 were oil wells, 19 gas wells, and 82 dry holes. Drilling during 1941 was 68 per cent of 1940, and the ratio of dry holes to producers, I to 4, was the greatest since 1935. Of these dry holes 43 were drilled in proven fields and 39 were wildcats. One new oil field and one new gas field were discovered as a result of the 1941 wildcatting program. However, numerous extensions were made to the existing fields, which, although they were called extensions to proration areas, were in reality field discoveries, being on separate geologic structures. Southeastern New Mexico Lea County The Monument field was the largest producing field in Lea County, with 6,973,808 bbl. It was closely followed by the Eunice field, with 6,644,181 bbl.; Vacuum field, with 4,800,608 bbl. and Hobbs, with 3,624,159 bbl. Hobbs field, however, still has the largest total recovery, this being 97,407,929 bbl. at the end of 1941. The new oil-field discovery in Lea County during 1941 was the Salt Lake field, T. 20 S., R. 33 E. The discovery well was Leonard-Welch State No. I, NW. NW. of sec. 18, T. 20 S., R. 33 E. This well was drilled to a total depth of 3103 ft. and was completed for an initial production of 250 bbl. per day pumping. The oil is 26" gravity and the producing horizon is in the San Andres limestone of Permian age. The discovery well was completed on June 22, 1941, and since that date four more producers have been completed, with no failures. The area is about 10 miles north-west of the Lynch pool, to which the oil from this field is being trucked because there is no pipe-line connection. The greatest drilling activity during 1947 was in the Maljamar field of western Lea County, with 62 completions, 59 being oil wells and 3 dry holes. The limits of this pool are now being defined on the north and south but to date have not been defined either to the east or west. The total number of 40-acre oil-producing units in the field at the close of the year was 158. On April I, 1941, a pressure-maintenance project was installed at the southern end

Jan 1, 1942