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By Carle R. Hayward

LEAD ore smelting plants have been operating in general at reduced capacities and secondary lead has assumed relatively more importance during the last year. Present smelting practice results in a large amount of dross, often over 25 per -cent, from blast-furnace lead. This is usually treated at a fairly high temperature in a reverberatory furnace to remove part of the lead and produce a matte-speiss product which is shipped to a copper plant. Few smelters are satisfied with this 'treatment. The fume losses are high and the matte-speiss contains considerable lead. It would seem that a fruitful field for research was open here.

Jan 1, 1934

By Walter Miller

PETROLEUM refining, like other industries in the United States in 1940, focused much attention on its duties and opportunities in the field of national defense. In counter-distinction to the situation during the World War; the industry is well constituted as LO existing equipment, processes, and capacity together with planned additions to handle any demands that may be made upon it by the defense program needs. Evident throughout was the growing sense of ability to manipulate oil molecules for the production of materials not hitherto considered as being available commercially from petroleum The development and application of catalytically-induced reactions on a broad front is one of the distinguishing characteristics of refining progress during the year.

Jan 1, 1941

By Everett G. Trostel

AMERICAN industry in 1943 emerged from the construction phase into the production phase, and American military operations passed from preparation into full action in the many theaters of the global war. The increased pace of industrial and military operations has resulted in a tremendous demand for petroleum and its products.

Jan 1, 1944

By Lucien Eaton

INCREASED mining activity during the past year has brought to light changes in mining practice and advances in technique, born and incubated in the period of depression from which the mining industry is now emerging. Although the tendency toward large output from individual mines has continued, a salutary trend is evident toward greater efficiency at small mines, in which the gold mines of Canada have led the way. Improvement in excavating machinery and washing plants for small placers has continued, and knowledge of the possibilities and limitations of this kind of equipment has increased. Greater portability through sectionalization has been the keynote. Power, shovels and draglines mounted on caterpillar treads move from one deposit to another under their own power, and floating washing plants mounted on pontoons can be taken down, moved, and set up again by a small crew of men in only a few days.

Jan 1, 1937

By AIME AIME

MOTHER example of the broad field that is covered by the mining industry is the recent erection by the Phelps Dodge Corp. of a modern hospital building at Douglas, Ariz., and an identical one at the rejuvenated mining town of Morenci. Managers of even small mining properties are often called upon to build schools, houses, stores, maybe a jail, and provide sanitary arrangements, possibly the while acting as mayor of the town. Those who direct larger properties may have to build hospitals, as in the present instance, construct sewage disposal plants, and sometimes even build and manage railroads. A mining camp achieves its reputation among mining men not entirely by the grade or amount of its ore, or the skill of the operating staff in mining and milling it at a profit-the operation soon acquires a reputation as either a desirable or an undesirable place to live, regardless of its remoteness from what is euphemistically termed civilization. Such a community is indeed fortunate if it can boast of a good hospital.

Jan 1, 1940

By William L. Batt

FROM the time the Japs overran the Far East, the United Nations faced a serious military problem in the critical shortage of many raw materials desperately needed to prose¬cute the war on two fronts. For many months this critical shortage threatened substantially to limit the gigantic effort to get shooting equipment into the hands of the fighting men on the far-flung battle lines. Now this crisis has been met. Solvency in raw materials has been achieved. Simply stated, this job of producing solvency has been done by "cutting cloth to fit the garment." This does not mean that we have all the raw materials we need. Unfortunately, a few raw materials are still short, thereby limiting the total production of certain war goods, or making these goods less effective. Where the supply of raw materials is known to be limited, however, substitutions have been made or production schedules have been geared to the amounts available, and an over-all balance has been achieved between various parts of the war-production program.

Jan 1, 1943

By H. H. Otto

COMPARED with 1939, the year 1940 has seen no material change in the production of anthracite. Many factors seem to indicate a stabilized anthracite production of approximately 50 million tons per year. The present war has stimulated demand in the Cana¬dian and New England markets, which were formerly furnished with a portion of their needs from Great Britain and other European countries. Neither has there been any material change in the "bootleg coal" situation. This problem is more serious in the Southern anthracite field than in the Hazleton, Wilkes-Barre, and Scranton areas. One reason for this is the nearness of the Southern field to the large anthracite markets in Philadelphia, Washington, Baltimore, and Harrisburg. During the past year no new large

Jan 1, 1941

By Paul F. Kerr

QUARTZ of a certain kind, is one of our strategic minerals, and Brazil is probably the one important available source. Crystals of quartz of suitable size and perfection for piezoelectrical application are rare; their most outstanding use is in radio work. Clear quartz, or "crystal," free from twinning, cracks, foreign particles of other disturbing lines of growth, and gaseous or liquid inclusions, is cut into plates which provide excellent control of frequency in broadcasting. The squares or rectangles are less than a millimeter in thickness and ordinarily on the order of 1 in. along each side. They are cut at definite angles with respect to the axes of the crystal, and ground with opposite surfaces parallel. Each small slab must be a section of one crystal, uniform throughout in atomic alignment. The thickness of the chip controls the frequency of a broadcast and it is most important to have the plates oriented and ground with utmost precision. Opposite surfaces are parallel to within 0.001 mm. and expansion or contraction due to the temperature is limited to one part in a million.

Jan 1, 1942

GENTLEMEN : Herewith are transmitted the reports of your Treasurer and the Chairmen of your standing committees on Admissions, Membership, Papers and Publications, and Library for the calendar year 1931. To these reports you are referred for further details of the year's activities. Finances.-Depressed industrial conditions prevailing throughout the year were reflected in a substantial decline in current revenue. Aside from interest on sundry special funds (but including that from the Life Membership, Library, and General Reserve Funds) total receipts amounted to $168,274, compared with $194,636 in 1930. The principal items of decrease were $17,000 in advertising income from the monthly magazine MINING AND METALLURGY, and about $9,600 in dues and initiation fees. Of this shrinkage $4,000 is accounted for by decrease in the number of new members enrolled; and $5,600 by diminished income from current dues and arrearages. This naturally has coincided with an \ increase in delinquency and "drops" or suspensions for nonpayment of dues. The decline in advertising income, amounting to 38 per cent as compared with that of 1930, in general paralleled the experience of all technical and trade publications; and it is problematical whether 1932 will show as large a return from advertising as did 1931.

Jan 1, 1932

By Charles F. King

THE only investigations on record of the reactions occurring during the Bessemer blow are of charges containing a large percentage of manganese, with the exception of two partial analyses by Snelus and Barker of the. English method, where a low percentage of manganese was used. They do not give the analysis of the spiegel, nor do they report any graphitic carbon after the first stage of the process. Both report only traces of manganese after the first stage until the addition of spiegel. The slags corresponding to the samples of metal were not analyzed.

Jan 1, 1881

NEW MEMBERS The following list comprises the names of those persons who became .members during the period of Jan. 10, 1918, to Feb. 10, 1918. ANTISELL, TONER, Min. Engr.; Supt., Great Falls Mine of Maryland, Chevy Chase, R: F. D. No. 4, Washington, D. C. BAKER, RAYMOND FRANK, Geol:, The Texas Co., Producing Dept., Box 362, Tulsa, Okla. BERTON, ADRIEN, Chief Engr., Corocoro United Copper Mines, Ltd., Corocoro, Bolivia. Buck, WILMER EARLE, Met., Curtis & Co. Mfg. Co., Hamberger & Kienlein Aves., St. Louis, Mo. BUELL, WILLIAM H., Asst. Director, Experimental Station, E. I. duPont de Nemours & Co., Wilmington, Del. CARDENAS, FEDERICO F., Mgr., Cia. Minera Nazareno y Alicante, S. A., Allende, No. 112, Saltillo, Coah., Mexico. CHEVALIER, JEROME A., Pet. Geol., The Carter Oil Co.; Exchange National Bank Bldg., Tulsa, Okla. CLEAVES, DANIEL LUNT Supt., St. Joseph Lead Co., Herculaneum, Mo. CLOTHIER, GEORGE A., Resident Min. Engr., Province of British Columbia,

Jan 3, 1918

By PAUL P. ZElGLER

Rapid growth of the aluminum industry continued through 1948 with an acute shortage of the metal in all forms marking the year. Estimates based on shipments made during the first nine months indicate that, in 1948, the industry shipped more than two billion pounds of aluminum products or roughly four times the amount shipped in the greatest peacetime year prior to the war. The rapid expansion of the aluminum industry is particularly reflected in the production of sheet. Last year, the industry as a whole shipped an estimated 40 per cent more sheet than was produced in the peak war year of 1944.

Jan 1, 1949

By S. A. Mersol, C. T. Lynch, F. W. Vahldiek

The room-temperature microhardness of as-grown and annealed MoaC single crystals was measured on the (0001), {2110), and1012) planes using Knoop and Vickevs indenters at loads ranging front 25 to 1000 g. The orientatimz dependence of hardness with respect to crystal axes was also studied. The average random hardness of as-grown crystals was determined to be 1520 kg per sq nm. Annealing to 2000°C decreased. the average hardness by 150 units. An increase in hardness after annealing at 2200 ;C was noted. Optical and electron microscopy revealed slip and twin traces on all planes studied, as produced by mi-cvohavdness indentations. Basal (0001)(2i10) slip was determined to be the primary slip system and was substantiated by electron transmission microscopy. A secondary {1010)(2110) slip was produced by mi-crohardness indentations. The lattev also produced twinning- of the {10i2)[0001] type, as proven by electron diffraction. Electrical resistivity and elastic-modulus anisotropy were found and correlated with hardness anisotropy and Mo2C crystal structure. Elastic-modulus values were obtained by microhard-uess and ullrasonic methods. Bonding mechanism of Mo2C is discussed. ROOM-TEMPERATURE microhardness indentations are useful for studying hardness anisotropy, slip, and twinning in brittle materials. Slip has previously been produced in this manner in and WS~~.~ Recently, the authors5 reported slip of the {10i0)(11~0) type produced by high pressure and microhardness indentations on hexagonal TiBz (c/a = 1.066) single and polycrystals. This slip system was also reported by French and ~homas' and Taka-hashi and ~reise~ for hexagonal WC (c/a = 0.976) crystals. These results suggest that prismatic rather than basal slip is favored in hexagonal nonmetallic materials having a c/a ratio considerably less than the ideal (1.633). Buerger precession and cylindrical X-ray rotation patterns were previously' taken on cleaved sections of the Mo2C single crystals studied in this work. Th~y were found to be hexagonal MoaC with a. = 3.0233A, co = 4.7344A, and C/O = 1.5660. The latter ratio is close to that of the beryllium metal (c/a = 1.57), which slips primarily on the (0001) plane: but also slips on the (1010) planes.'0 ~irconium" (c/u = 1.59) and titanium12 (c/o = 1.59) deform mainly by slip on nonbasal planes which contain a close-packed direction. This is due to the fact that for these two metals the initial resolved shear stress for slip on the (10i0) prismatic planes is lower than that on the (0001) plane. The prominence of basal rather than prismatic slip in metals of high c/o ratios is shown by cadmium (c/a = 1.89), zinc (c/a = 1.86), and magnesium (c/a = 1.62) which deform mainly by basal slip. However, in case of the latter, by stressing magnesium crystals in tension or compression parallel to the basal plane, slip on (10i0) planes can also be produced.13 Several hardness values for polycrystalline Mo2C are reported in the literature: Biickle ' and Samsonov'~ give a value of 1800 and 1479 kg per sq mm, respectively, at a 100-g load; and Kieffer and Benesovsk~'~ report a value of 1950 kg per sq mm at a 50-g load. ~ott'~ reports a Vickers hardness value of 2000 kg per sq mm, with the load unspecified. A Rockwell A hardness value of RA = 88 has also been reported.'' In the present work, for comparison with single-crystal Mo2C hardness values, a Khnloo value of 1600 It 150 kg per sq mm was found on 99.6 pct pure and 99 pct dense hot-pressed Mo2C. This work was undertaken partly to explain the considerable differences in hardness values reported for polycrystalline Mo2C. EXPERIMENTAL The Mo2C single crystals investigated were prepared by a Verneuil-type process using an electric arc by the Linde Co. of the Union Carbide Corp.lg The largest specimens grown were boules 7 mm in diam by 40 mm in length. The crystals had an average density of 9.04 g per cu cm, with a Mo + C content of 99.8 wt pct. The major impurities were: 100 ppm each Na, Zr, and Ca; 85 ppm 0, 55 ppm Fe, and 10 ppm each Cr and Ta. The crystals were found to be carbon-poor, the average carbon content being 5.73 wt pct (stoichiometric value is 5.89 pct). The molybdenum content was found to be 94.08 pct, which is nearly stoichiometric. Electron-microprobe traverses of selected specimens were done with a Phillips-AMR microanalyzer. Thin-film and carbon replicas were used to prepare electron micrographs. This work was done with a JEM-6A electron microscope. Prior to optical and electron-optical studies, specimens were mounted in Lucite and polished on a vibratory polisher using diamond-paste grades ranging from 9-1 p and Linde A powder for up to 48 hr. Dilute nitric acid was used for thin-section polishing and chemical etching for 1-15 min. Electrical-resistivity measurements at room temperature were taken with a Rubicon bridge, using gold contacts. For hardness measurements, a Tukon Microhardness Tester Type FB with Knoop and Vickers indenters was used. Measurements were taken at loads ranging from 25 to 1000 g; however, the 100-g load was chosen as the standard load. All measurements were taken at room temperature. Indentations of cracking classes 1 and 2 only were considered for hardness determinations.20)21 (There are six cracking classes, ranging from "class 1" for a perfect inden-

Jan 1, 1967

By J. L. Lytton, J. E. Dorn, L. A. Shepard

Single aluminum crystals were subjected to creep in simple shear on the (111) planes in the slip direction. The activation energies for creep were calculated from the effect of small abrupt changes in temperature on the creep rate just before and immediately following the temperature change. The results definitely establish the fact that creep of single aluminum crystals occurs by-three unique processes, characterized by thethree distinct and isolatable activation energies: The 35,-500-cal-per-mole activation energy obtained at the highest temperatures was ascribed to a dislocativationtion climb process; the 28,000-cal-per-mole activation-energy process, occurring over the intermediate-temperature range was attributed to a cross-slip mechanism; and it was suggested thot the 3400-cal-per-mole process observed below 400°K may be the Peierls energy. THE most pertinent question regarding the phenomenon of creep in crystalline materials is concerned with the identity of the crystallographic mechanisms of deformation that control the creep rate. For many years slight progress was made in uncovering the basic mechanisms for creep. Over the past 10 years, however, two parallel lines of investigations have contributed to a more definitive understanding of the processes involved in creep. The extensive development and maturing of dislocation theories for deformation of crystalline materials' proved to be of paramount importance for this progress. And second in importance was the replacement of the former prosaic methods of creep testing by new techniques'." which were especially

Jan 1, 1959

By AIME AIME

THE Wednesday morning session was devoted entirely to the consideration of the tentative code for coal mine ventilation. A. W. Hesse is chairman of this subcommittee. E. A. Holbrook presided at the session and assisted by A. W. Hesse and George S. Rice, gave the historical background of the movement for a ventilation code. They stressed the point that this was to be an engineer's code, and that it was hoped that it might serve as a valuable guide to operating companies in securing greater efficiency as well as safety in ventilation. The discussion was continued into the afternoon session, and by adjournment the entire' code had been covered.' Many sections were referred back to the Committee for further study and several new sections were suggested. The various opinions and new ideas brought out during the discussion proved very valuable and. contributed much to the progress being made in the preparation of this code.

Jan 1, 1929

By K. A. SPENCER

THE production of soft coal from strip mines in the United States has shown a remarkable growth in the last sixteen years, increasing from one and one-quarter million tons in 1914 to approximately twenty-two million tons in 1929. This is a growth of approximately 1660 p& cent, as compared with a growth of approximately 20 per cent in the underground mines for the same period. But even with this marked in- crease the total tonnage produced by open-face mining represents only 4 per cent of the nation's soft coal tonnage.

Jan 1, 1931

By John Hays, Hammond

IT is both a pleasure and an honor to be a guest of the Institute and I thank you, Mr. President and fellow-members, for giving. me the opportunity of meeting you this evening. My esteemed friend, President Smith, has requested me to do a bit of "reminiscing" as to the earlier years of my career as a mining engineer, which has now covered a period of fifty years. Let me reassure you by promising that my narrative will not include all the experiences I have had over that long period. You will, I trust, pardon what might seem egotistical but I do not see how a personal narrative could well be otherwise.

Jan 1, 1928

By W. E. Wrather

SERIOUS consideration was given by the Petroleum Division to a wide variety of subjects, during six busy sessions at the Annual Meeting. Beginning with a joint session on engineering research and production engineering, Tuesday afternoon, conducted by E. A. Stephenson and H. C. Fowler, problems of petroleum technology, domestic and foreign production, proved oil re- serves, economics, and stabilization were mooied almost without interruption until nearly everyone was "talked out,' and the meeting was adjourned at the end of the annual Petroleum Division dinner, late Thursday night.

Jan 1, 1933

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 AIME AIME

THREE of the addresses presented at this interesting and important session are printed in full else- where in this issue. The fourth, Mr. Hewett's paper, on "Cycles In Metal Production" has been issued as Technical Publication 183, and an abstract of it was published on page 162 of last month's issue. The general discussion that followed these four important papers is given in full below. S. A. TAYLOR: I would like to ask Mr. Veasey whether the control of oil in pools includes royalties, and, if so, in case of a new pool how are you going to control, or rather how are you going to describe the limits of that pool?

Jan 1, 1929