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By M. King Hubbert

THE growth of human knowledge is an evolutionary process. Historically our separate sciences came into existence as people became interested in various apparently unrelated domains of phenomena, and in this manner we acquired the sciences of physics, chemistry, astronomy, biology and geology. As various of these sciences became established, cognizance of them came to be taken by the universities and in this manner there arose the traditional departments of physics, astronomy, chemistry, biology and geology of our American universities. As there was no particular rationality in the boundaries separating the various sciences, in the university departments the jurisdiction of each has assumed quite arbitrary limits. In the domain of earth phenomena the first science to grow up was that of geology, which arose originally from the activities of the collectors science dealing with directly observable terrestrial phenomena for which elementary rational explanations were offered. The traditional treatment of phenomena by the science of geology has rarely been with more than an elementary regard for the fact that these phenomena were also phenomena of physics and chemistry. Since the latter part of the nineteenth century, a new approach to terrestrial phenomena has been emerging and becoming of so great a significance that it can no longer be ignored. This approach has been made by people trained primarily in the sciences of physics and chemistry, who have investigated terrestrial phenomena as constituting phenomena of their respective sciences. In this manner we have acquired the so-called "borderland sciences" of geophysics, the physics of the earth, and of geochemistry, the chemistry of the earth. Neither of these fields is new, having arisen chiefly at the hands of European investigators during the latter part of the nineteenth century. The European universities have long since given official recognition at least to geophysics, by the establishment of departments or institutes of geophysics, which are on a par with the university departments of the other sciences.

Jan 1, 1938

By A. O. HAYES

SYSTEMATIC methods of ore-finding are looked to the more as increasing production requires greater supplies of raw materials. Unrelenting search for new sources of supply is necessary, and all the skill of science must be displayed both in methods of discovering and recovering the minerals necessary to the demands of present-day life. To this end most national governments have some sort of a geo- logical survey and there is a growing understanding of the desirability for cooperation between federal and state or provincial organizations and also financial assistance, from state and private universities, mining companies, railroads and manufacturers. Such surveys are now being directed by well trained geologists selected from federal, state and university departments. Large-scale maps are being prepared and better geo- logical interpretation made, more thorough chemical and physical examinations are being made and original search is fostered, with the result that successful prospecting is better directed, new mining regions are more likely to be discovered, and the life of. old camps lengthened.

Jan 1, 1931

By Sylvan Z. Beer

The factors that determine the yield and crystal size in the two-temperature synthesis of A lp were examined. Low yields and small crystals were associated with low temperatures and pressure. Attempts to grow large crystals in the critical and supercritical region of phosphorus were unsuccessful. Crystal size increases markedly at elevated temperatures. Crystals grown at temperatures as high as 1450° C fluo-resced, under uv excitation, at energies close to the estimated band gap of about 2.4 ev, while crystals grown at lower temperatures tended to fluoresce in the red region of the spectrum. Those grown in the supercritical region showed no ALP fluorescence. Heating the high-temperature-grown ALP under vacuum greatly increased its fluorescence efficiency and moved the emission peak to higher energies. I HE III-V compounds, with few exceptions, have been prepared by the two-temperature method. In its classic form this technique is applicable to closed systems where at least one of the components, in this case the column V element, is a liquid or a solid with a high vapor pressure. One advantage of this method over flow systems is in its simplicity. In addition, because it is a closed system, it can, under the circumstances to be described later, be run at higher pressures of the volatile species than in flow systems. In instances where the III-V compound is soluble in the parent III metal to about 1 mol pct or higher, solution growth can be made to take place by slow cooling. This, for instance, is one way in which single-crystal GaP1 and Inp2 have been grown. Initial attempts to synthesize and grow A1P by this technique were not too successful; the yield was low and the crystals obtained were exceedingly small. The conditions required for improving the yield and growth by this technique were, therefore, sought. Two obvious conditions which could be controlling were examined. These were the temperature of the aluminum and the pressure of the phosphorus. The range of temperatures studied extended from about the melting point of aluminum, 660° to about 1450°C. The latter is dictated by the vapor pressure of aluminum which reaches about 1 Torr at that temperature and the limitations of the materials of construction as described in the next section. The pressure range of interest covers from below 1 atm to above the critical pressure of phosphorus, 82.2 atm. EXPERIMENTAL The Temperature of Aluminum as a Variable. A series of experiments were run in the conventional two-temperature manner. All refractories and quartz were dried by heating at 800° to 900° for a minimum of 24 hr, and usually much longer, before use. The aluminum

Jan 1, 1969

By C. J. Bier, J. F. O?Keefe

THIS study was carried out with copper because it represents the simplest form of sintering, in that but one metal is involved and all reactions occur in the solid state. [ ] The present work will cover three variables affecting the sintering process; namely, briquetting pressure, sintering temperature and time in hot zone. Although strength and dimensional changes were observed, this is primarily a metallographic study of the sintering process in copper. The term "sintering" should be understood to mean the process by which the metal powder particles of the compact become united into one body. MATERIAL USED The copper powder used was made from reduced copper oxide, and is typical of a grade used for the mass production of parts formed of metal powders. The screen analysis of the powder was as follows: [ ] The minus 325-mesh analysis was made by using a Roller Air Analyzer.1,2 The apparent density is here defined as the weight per cubic centimeter of the [ ] loose, unpacked powder as measured with the Hall flowmeter. The value for the powder used was 2.57 grams per cubic centimeter.

Jan 1, 1944

By Harry J. Evans

DURING the fury of the conflict it was believed quite generally that World War II was being fought for and would accomplish a permanent peace. Yet, before the guns were actually stilled on all fronts, the American people realized that the devastated world would continue to be dominated by suspicion and uncertainty. The misunderstandings which rapidly developed indicated that it may prove unwise to rely wholly on mutual international agreements and contracts to avoid war. Before the celebrations of V-Day died down serious thought was being given toward measures for preparedness for the next conflict. Along with a realization of the enormous loss of life caused by the destructive forces of war, the American people came to understand the seriousness of the rapid and unwarranted depletion of our natural resources. During the last half of 1945 the question of stock-piling strategic and critical raw materials for a future national emergency became an intensely live subject.

Jan 1, 1946

By R. A. Walker, R. G. Bradburn, B. C. Flintoff

The events which led to computer control of the grinding circuit at Brenda Mines are described, beginning with mill operating philosophy. High production rates are encouraged so that, despite severe upstream disturbances, a manual control method to meet this philosophy had developed. Unfortunately, due to the time interval between manual control adjustments, losses in production resulted. An analog control method was devised and, although superior to manual control in some situations, was found to suffer from several practical limitations. The data logging capabilities of a control computer seemed warranted. Circuit testwork combined with an analysis of operating data showed that (1) metallurgical personnel at times could increase production rates by as much as 10% over that achieved by grinding operators; (2) the chosen data base required an increase of 2% or more to be statistically significant; and (3) for a 2% increase there would be a significant rate of return of investment in computer installation. Consequently one grinding circuit was fully instrumented, and a rented computer was installed by Brenda personnel. Prior to installation, Brenda metallurgical and instrumentation personnel were trained in the use of the computer. An experimental program was devised with short and long-term objectives. The short-term objective was to develop a practical control strategy which would yield immediate production improvement. This goal has been successfully met as described in this paper. Statistically significant increases in excess of 2% have been established. Work is being completed for the permanent installation of computer control on all four grinding circuits at the present time. Long-term objectives are (1) off-line analysis of the circuit using mathematical models of process units; (2) on-line experiments to study alternative control tactics; and (3) possible expansion of computer facilities to the crushing plant.

Jan 1, 1978

By W. R. Hudspeth

AS an outgrowth of its spodumene recovery operation at Kings Mountain, N. C., Foote Mineral Co. has been recovering a heavy mineral by-product. Foote leased this idle plant in 1951, reactivated it, using a new spodumene recovery process, and purchased plant and properties in October 1951. While the operation at Kings Mountain is primarily concerned with the production of spodumene concentrate, pilot plant work determined that the pegmatites also contained heavy minerals including cassiterite. Plans were made to recover the heavy minerals as a by-product and the flowsheet incorporated these facilities when the mill was modified for the new spodumene recovery process. The orebodies consist of spodumene, feldspar, quartz and mica. Apatite, tourmaline, and beryl are present in small quantities. The wall rock is pre- dominantly hornblende shist. The heavy minerals, including cassiterite, columbite, pyrrhotite, monazite, pyrite, and rutile represent about 0.2 pct of the ore. The fine-grained heavy minerals are disseminated throughout the dikes, apparently unassociated with the spodumene. The pegmatites are quarried and secondary breakage is by mud-capping and block-holing. Power shovels load into trucks transporting the ore to a coarse ore bin. A Telesmith 10x36-in. apron feeder delivers the ore to an 18x36 in. Traylor Jaw crusher adjusted to discharge -3 in. product to a primary conveyor. The conveyor delivers to a 4x5-ft Tyrock single deck vibrating screen using 3/4 in. cloth. The screen undersize is elevated to the crushed ore bin. Screen oversize goes to an Allis-Chalmers Hydrocone Crusher fitted with 4 in. concave and set to deliver approximately 66 pct minus 3/4 in. The crusher discharge returns to the primary conveyor. The crushing and screening installation has a capacity of about 60 tons per hour. Spirals The crushed ore is delivered at a rate of 350 tons per day to two 6x8-ft Hardinge Pebble Mills, equipped with 20 mesh Ton-Cap trommel screens. The screen oversize is pumped to a 12-in. hydroclone for primary desliming. The hydroclone underfl spirals. There is no heavy mineral loss in the hydro-clone overflow. The spirals bank consists of eight 5-turn Model 24-A Humphreys Spirals. The top port and the last four ports of each spiral are blanked, the remaining nine port splitters are adjusted to remove about 5 pct feed weight. The heavy mineral rougher concentrates are upgraded on a Deister Overstrom table. The spiral concentrates contain approximately 4 pct heavy mineral, and the spiral reject, which goes to another section of the plant for spodumene recovery, contains about 0.03 pct heavy mineral. There is an interesting feature in the spirals installation. An adjustable splitter mounted on the discharge boxes splits out a mica fines product containing very little heavy mineral. The mica product is cleaned by spiralling and screening. Thus the spirals recover two products; mica, and a heavy mineral rougher concentrate. Table Treatment The rougher spiral concentrate goes to a Deister Plato table, modified to receive a Deister-Overstrom No. 6 rubber cover with sand riffles. The table is operated with a 5/8 in. stroke, 270 strokes per minute, and a slope of 1/2 in. per ft from feed to tailings side. There is no slope adjustment from motion to concentrate end. Wash water consumption is relatively high, since the large spodumene grains tend to report with the fine heavy minerals. A middling band about 4 in. wide is maintained in order to produce clean concentrate. The middling, representing about 10 pct of table feed, is recirculated by air-lift. A band of concentrate grade coarse spodumene occurs just below the middling. This is removed and delivered to concentrate storage. The table tailing, containing approximately 0.7 pct heavy minerals, is returned to the spodumene feed preparation circuit. The heavy mineral table concentrates are approximately 45 pct cassiterite, 33 pct columbite, 14 pct pyrrhotite and 8 pct monazite, together, with some rutile, pyrite, and copper from blasting wire. Concentrate is collected at 24 hour intervals. and dried. If the concentrate remains in wet storage appreciably longer surface oxidation takes place which seriously interferes with the subsequent magnetic separation process. About 150 lb of heavy mineral concentrate is produced per 24 hours and shipped to the company's plant at Exton, Pa. for final separation into tin and columbium concentrates.

Jan 1, 1952

A concept gaining attention among rock mechanics researchers in studies of soil-structure inter- action is the use of compressible packing between the structure such as tunnel lining and the soil or rock. Lester H. Gabriel, provided information about work on this concept at the II Symposium on Rapid Excavation, October 16-17, 1969, Sacramento State College, Sacramento, Calif. It is well-known that loads transmit their effects to those locations which deform least. Traditionally, the question to be answered by the structural engineer is how rigid the structure ought to be. The stronger the structure, the more resistant it becomes to deformation. If it is more rigid than the surrounding strata, the structure acts as a pillar, focusing load on itself. However, if the structure is less rigid than the surrounding strata, blocking or packing between the structure and the enclosing material facilitates the formation of soil or rock arch. The object then is to design and build structures such as tunnel linings, which harness the advantages of carefully planned small movements. Tests on plaster cylinders imbedded in granular sand and loaded were compared to those of plaster cylinders protected in sheathing of polyfoam rubber. The compressible sheath permitted support of up to ten times greater loads Gabriel, Lester H., "Principles of Soil-Structure Interaction Applied to Tunnel Linings." Hecla Mining Co. has successfully used shotcrete with substantial cost savings for ground support purpose. To date, the use of shotcrete in Hecla's operations has been limited to openings where long-term high quality support was required, in exceptionally difficult ground, and to a limited degree in stope support. Experience with both the wet and dry process indicated that the latter was better for their applications. The availability of effective accelerators which reduce losses from rebound, give high-early strength and permit placement in wet conditions, led to this conclusion. The gross cost under such conditions as those at Hecla, including rebound losses and overshooting, is estimated by Hecla to be $51 per cu yd.

Jan 12, 1969

By H. W. Young

Development of high-tension outdoor substations during the past few years has been due primarily to economic reasons. The demand for power in small communities could not be met with the conventional and Fig. 1.—33,000-VOLT step-up outdoor air-break switch and substation installation outside of a powerhouse generating at 2300 volts stepping up to 33,000. Twenty-one coal mines are supplied from lines leading from this installation. comparatively expensive indoor types unless the rate for service was materially increased. To prove that the problems lncident to development have been solved successfully, it is only necessary to point to the wide adoption of outdoor substations by utility companies. Passing at once to the question as to whether outdoor substations are applicable to

Jan 1, 1920

By AIME AIME

TWO papers, "Calcium, Strontium, and Barium Metals," by Charles Hardy and Paul M. Tyler, and "The Mining of Gems and Ornamental Stones by American Indians," by Sydney H. Ball, were presented before the Rare Minerals and Metals group at its session Tuesday afternoon in the Auditorium. Donald M. Liddell, chairman, presided. Mr. Tyler summarized the first paper, outlining the uses, history, occurrence, manufacture, production and trade, markets and prices of the three metals. In discussion, in response to the chairman's query on "what are they doing in Russia with calcium, strontium, and barium," Guy C. Riddell replied that nothing is being done on a production basis. The great rare metals plant in Moscow is active, however, on other elements. "They are making radium chloride, uranium oxide, vanadium, cadmium, tungsten, molybdenum, selenium, antimony compounds; and mercury, nickel and arsenic are under production at interior plants. The rare metals plant is busily conducting research on beryllium, rhenium, lithium, bismuth, strontium and zirconium. These are the main rare metal activities. Much hard-alloy work. for cutting and facing, is under way:

Jan 1, 1933

W. C. MATTESON (communication to the Secretary*).-The criticism and question raised by Arthur Knapp regarding the standardization of nomenclature is most important. Faulty rock classification-is generally the result of carelessness or ignorance on the part of the driller. Two remedies might be suggested. In a field where several large companies are operating on an extensive scale, a geologist from each concern might be assigned to superintend the gathering of well-log data and the classification of samples. The geologists from the several operating companies might then combine their data, which would doubtless give valuable information to all interested parties. At present, coordination is not a big factor, unfortunately, but the time will come when conservation will demand such systematic coordination on the part of competing companies. The second remedy lies in instructing and educating the driller to a thorough understanding of the importance of an accurate log and correct classification of the various formations. The writer does not agree with the statement that "90 per cent. of the logs as taken today are absolutely worthless to any one but the one who has taken the log." While mistakes in nomenclature often occur, the driller is generally able to classify the important water-, oil-, and gas-bearing formations with a fair degree of accuracy. Such information is often sufficient to permit accurate correlation and also constitutes valuable data for projection purposes. It must be borne in mind that to attempt to use well-log data in a strict scientific sense of accuracy is impracticable and impossible. A broad interpretation and a comprehensive knowledge of the practical limits of such' information are essential in applying it successfully. Even experienced geologists do not always agree on rock classification. The question as to what constitutes correct nomenclature should receive the earnest and immediate attention of geologists, operators, and producers. Although standard textbooks on geology give correct definitions and descriptions of the general rock species, such textbooks fail to develop the subject in sufficient detail for the work under consideration. A committee composed of appointed members from the American Institute of Mining Engineers, the Geological Society of America, and the

Jan 6, 1917

By Donald A. Dahlstrom

In 1961 it became increasingly more evident that significant technological changes must be made in minerals beneficiation. The status quo in technology in today's competitive markets will not be tolerated. Higher productivity, greater recoveries and newer and better products must be sought and incorporated with lower operating costs. In other words, "when you build a new mill, don't build an old mill." Recommended reading for proof of the vital necessity of new methods and techniques is in the September 1961 issue of MINING ENGINEERING. The article by one of MBD's cherished and true veterans, E. H. Rose, is entitled "Iron Ore: The BIG Picture". Because of new beneficiation methods for iron ores, nearly 47 million tons of plus 60% iron concentrates will be produced and another 40.1 million tons of capacity will be under construction or committed. Thus in a relatively short period, 87 million tons of this high-grade iron concentrate with record low silica will be available. As Mr. Rose also points out, "in gross tons, without allowance for better grade, this is the equivalent of almost exactly two-thirds of all iron ore used for all purposes in the U.S. and Canada in the peak years of 1953 or 1957." Needless to say, improved mineral beneficiation methods have had far more reaching effects than just the production of higher grade iron concentrate.

Jan 2, 1962

By Robert Glass Cleland

THE DEATH of William E. Dodge occurred at a time when, all unwittingly, the company in which he had so long been the dominant factor was about to break with its old practices, its old traditions, its old interests, and transfer its major activities three fourths of the way across the continent and engage in an enterprise that differed almost as much from the original Phelps Dodge undertakings as the rough, arid mountains of the new region differed from the green hills and valleys of New England. To understand the effect of this transformation upon the fortunes of Phelps Dodge, one must change the setting of the present narrative from the familiar locale of the Atlantic seaboard to the land of "distance, silence, and solitude," that men called Arizona. In 1880 that Territory was one of the last frontiers of the Old West. To the Spaniards it had been a land of mystery and fable, the limit of the King's settlements, the far edge of the rim of Christendom. Through it Coronado; in a vain effort to find the fabulous Cities of Cibola, had led "the most brilliant company ever assembled in the Indies to go in search of new lands." Below its southern border, Father Kino, the "steel-thewed" Jesuit described by his

Jan 1, 1952

By N. R. Tipman, G. E. Agar, L. Paré

The flotation chemistry of the commercial INCO matte separation process was investigated. The slow cooling of Bessemer converter matte forms discrete phases of Cu2S and Ni3S2 and a Cu-Ni alloy. After magnetically removing the alloy, the Cu2S and Ni3S2 are separated by flotation at pH 12.4 (saturated lime) using diphenyl guanidine (DPG) as both collector and frother. DPG has been used exclusively in this flotation process because of its unusual selectivity for copper minerals. The surface product resulting from chemisorption of DPG onto theCu2S was identified as the double salt CU(DPG)2SO4.CU(DPG)2(OH)2. The adsorption followed Langmuir behaviour up to a monolayer coverage. In the absence of DPG, the rapid adsorption of oxygen by Cu2S in flotation pulps was observed. The surface product was identified as the insoluble basic copper sulfate CuS04.3Cu(0H)2 with the production of sulfate ion. In the presence of DPG, the oxidation reaction appears to be suppressed. The frothing properties of DPG and commercial frothers were compared. DPG is not a powerful frother. Batch flotation tests confirmed that DPG is a highly selective collector when compared to most sulfhydryl collectors.

Jan 1, 1976

By Frank Firmstone

IN Chemical Phenomena of Iron Iron Smelting, Mr. Bell gives the weight of materials required to fill furnaces of various sizes at the Clarence Works ; as this differs very much from the weight required for furnaces at Glendon, where anthracite and in agnetic and brown iron-ores are used, a comparison is interesting. Taking furnaces at Glendon of 4800 and 11,900 cubic feet capacity and comparing them with the Clarence furnaces of 6000 cubic feet and 11,500 cubic feet, we find that the 4800 cubic feet at Glendon and the 6000 cubic feet at Clarence required respectively

By John H. Schemel

Large Zircaloy-2 hammer or press forged bars did not exhibit the uniform excellent corrosion resistance to steam normally expected of the alloy in wrought form. Weight gains of coupons cut from forged bars were 40 to 60 mg per sq dm compared to the 28 mg per sq dm obtained on hot rolled sheet and strip. The mechanism of this corrosion and its relation to microstructure is discussed. After these observations, a solution heat treatment followed by rapid cooling was tried on coupons from eight heats of forged bars. The basket-weave structure resulting from the quench did not show agglomeration of intermetallic compounds. These coupons showed uniformly good corrosion resistance with weight gains very close to the 28 mg per sq dm expected of Zircaloy-2 after the 14-day steam test. A large forging was solution heat-treated and tested for structure, mechanical properties, and corrosion resistance. Corrosion resistance was excellent and uniform throughout the section. The normally anisotropic mechanical properties were changed to completely iso-tropic. Strength levels were raised while there was a small loss in ductility at the service temperature. Tempering of the quenched structure below the ß transus did not improve the ductility at the test temperature of 600°F. ZIRCALOY-2 end caps for nuclear fuel elements Zircaloy-2 is an alloy of 1.5 pct Sn, 0.1 pct Fe, 0.1 pct Cr, and 0.05 pct Ni, balance hafnium-free zirconium patented by Westing-house Electric Co. used in pressurized water reactors are machined from large hammer-finished forged bars. The bars forged for this application range from 3 1/2 in. to 7 1/2 in. squares. One of the tests used to evaluate Zircaloy-2 for this service is a 14-day exposure to very high-purity steam at 75oF and 1500 psi pressure. Normally wrought products will exhibit a black lustrous film of zirconium oxide after the test and show a weight gain of approximately 28 mg per sq dm. Coupons representing the forged bars exhibited a wide variety of corrosion results ranging from acceptable black coupons to some covered with white crystals of zirconium oxide that had weight gains of nearly 100 mg per sq dm. One of the most common effects was a white corrosion product that looked like a stain to some observers and the outline of massive metal grains to others. Very careful specimen preparation prior to the corrosion test did not affect the result and metallographic examination did not reveal a structural feature of a size and shape that would correlate with the corrosion product. In addition to the relatively poor corrosion resistance, the forged product was not as ductile as desired. The problem of obtaining uniform and more acceptable properties in these heavy-forged sections seemed to be a function of the microstructure of the metal and, in particular, the distribution of the intermetallic compounds. None of the four alloying elements however are appreciably soluble in a zirconium and are present as compounds which usually appear scattered randomly throughout the structure. Moudryl showed that the distribution of these intermetallic compounds in Zircaloy could be related to a ostringero corrosion failure. Grozier et al. discussed another structural defect that causes a similar corrosion effect. In this case, an elongated gas-void was determined to be the cause. M. L. Picklesimer held in his discussion of the Grozier paper that at least a part of the observed =stringersn were caused by the distribution of the intermetallic compounds. He proposed a

Jan 1, 1962

By S. A. TAYLOR

THERE is probably no other mineral industry of which the public has as much information and misinformation as it has of the coal industry. Unfortunately, however, the general public's knowledge of the coal industry, outside of the particular kind of coal it is accustomed to, by reason of use, is largely made up of information received from newspaper and popular magazine articles, in which the mine workers are depicted as overworked and mistreated men, and the coal operators as "coal barons." Those who have any specific knowledge of exact conditions in the coal industry know how unjust and un- fair such an opinion of the coal industry is, not only to the miner but to the operator as well. Many reporters and writers of magazine articles are misled by statements regarding the condition of the miners that are exaggerated and not founded on facts and, if an investigation of the conditions of the miner's work, his habitation and surroundings were fairly made, it would at least compel more truthful statements by those who write for public reading. That such an investigation would not reveal anything that was wrong, or anything to be censured or cured, no one, I think, would maintain, but I do think that any fair investigation of the facts would show that conditions in and around the newer and later-developed coal mines and communities would compare favorably with those of manufacturing districts, and that where the mines and com- munities are old and not very attractive places to work, or live in, they carry with them other considerations, compensating for these conditions, and cannot be remedied by reason of a lack of sufficient coal to warrant economically any costly changes.

Jan 1, 1926

By John R. Dyni

Colorado nahcolite deposits, estimated at 29 Gt, formed in an asymmetric permanent-lake basin whose waters were rich in algae and sulfate-reducing bacteria. Nahcolite (NaHCO3) occurs in oil shale of the Green River Formation (Eocene) as aggregates (62%), disseminated crystals (24%), and impure beds (13%). Because much of the nahcolite is nonbedded, it will be mined with oil shale and can be concentrated to marketable grade by crushing and screening. Impurities in nahcolite are kerogen, quartz, pyrite, and carbonate minerals. A promising new market for nahcolite is in the process of removal of sulfur dioxide from industrial stack gases. When heated, nahcolite reacts with sulfur dioxide to form sodium sulfate. Differences in thermally induced microporosity may explain why nahcolite is more reactive than trona, a Possible competitor with nahcolite for SO2 removal. Limited production of nahcolite at one or possibly two localities is expected in the next several years, but large-scale production is probably at least 10 years away.

Jan 1, 1982

By AIME AIME

PRESIDENT BASSETT'S gavel called the Annual Business Meeting to order shortly after 10 a. m. on Tuesday. On motion of Eugene McAuliffe, reading of the minutes was dispensed with and Mr. Bassett read his annual report of the year's activities as follows : During the year I have visited eighteen of the twenty- seven sections, making an average of GG 2/3 per cent. The invitation to come again has always been extended, but in only one case have I been able to visit the same section twice. Chicago entertained the president twice during 1930. Mrs. Bassett accompanied me on visits to ten sections. Everywhere we have found the most cordial hospitality and a gratifying enthusiasm for the Institute. If anyone had fault to find with the management or felt dissatisfied with what was being done, it was carefully concealed. I am happy to report to you an agreeable, helpful and progressive spirit in each of the sections visited.

Jan 1, 1931

By T. F. McCormick

THIS year, 1950, is the golden anniversary of the construction and operation in this country of a tube mill for the sole purpose of fabricating aluminum alloy tubing. For a short period prior to the beginning of this mill, aluminum alloy tubing was obtained from foreign sources or produced in mills fabricating other metals. Indeed, it was a very short period because aluminum itself was a newcomer in the field of metals. The first sheet rolling mill had been in operation just eight years and a rod rolling mill for the production of wire and cable had been functioning one year. The first tube mill for aluminum was built by the Aluminum Co. of America in May 1900 and started production with four draw benches and five men, including the mill superintendent. The building itself was a lean-to attached to a sheet-rolling mill at New Kensington, Pa. The cost of equipment, including the draw benches, dies, mandrels, and other tools, was about $5000. This figure seems absurd in the present day but nevertheless it was questioned at that time whether or not such a large sum should be spent to embark on a new and uncertain venture. The initial production system for the new mill consisted of casting round hollow ingots in a tilting-type iron mold, reducing the ingots to bloom size outside the plant, and finally drawing to size on the draw benches. This method of producing aluminum alloy tubing survived just two years, as blooms of satisfactory quality were not obtained consistently. It was superseded by the cupping method in which a 24-in. diam circle cut from a rolled plate was formed into a tube bloom using first a small cupping press and then a push bench. It was stated that tubing so produced was limited to a maximum diameter of 2 3/4 in. and to wall thicknesses varying from 12 to 24 gage. However, for the first time all the operations were performed at one plant and the result was a quality product. Later larger cupping presses and push benches were obtained and the method continued to be the principal one for aluminum alloy tubing for almost a quarter of a century. During the interim the use of a Alan Mannesmann -type billet piercer was explored and it was used to some extent, but failed to produce consistently a smooth inside surface suitable for drawing with aluminum alloys. Experiments started during the latter stages of World War I in the production of tube blooms with a hydraulic extrusion press, led to the use of this type of equipment to make tube blooms for further drawing during a change-over period extending from 1925 until 1930. At this time the cupping method was discarded completely. From these humble beginnings, the aluminum alloy tubing business expanded until well over six million pounds were produced in a single month in the United States during World War II. The major portion of this production was in strong alloys which did not appear in the tubing picture until 1022, when 17S alloy tubing was introduced for aircraft construction.

Jan 1, 1951