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By James R. Jones

The concern for air pollution goes back centuries as will be seen from this quotation: "Strife and coal, it seems, have a hand-in-hand historical relationship. It was thought by some . . . in the Middle Ages that burning coal filled the air with dangerous poisons. So great was the concern that in 1306 King Edward I of England passed the first and unquestionably the harshest, air pollution legislation edict that history will record. His proclamation declared the use of coal an act punishable by death." As related to coal mining the air pollution problem is primarily that of its customer when using the fuel. Thus the major impact relates to markets for coal rather than the actual mining operation itself. In the vicinity of the coal mine the problem is principally related to fugitive dust from roads, transfer facilities, loading facilities, crushers. etc., and particulate matter (dust or fly ash) from thermal dryers and air cleaning tables. FUGITIVE DUST Most state air pollution regulatory agencies now have rules and regulations requiring control of fugitive dust. This refers to dust generated from normal processing operations. A typical air pollution control agency regulation reads as follows: "Fugitive Dust" "No person shall cause, suffer, allow, or permit any material to be handled, transported, or stored; or a building, its appurtenances, or a road to be used, constructed, altered, repaired, or demolished without taking reasonable precautions to prevent particulate matter from becom-

Jan 1, 1973

By R. Steinitz, L. Seigle, R. Resnick

THE rates of growth of the carbide phases MC and M2C in the Ta-C and Cb-C systems have been measured at various temperatures and the results used to estimate the rate of carbon diffusion within the inter metallic phases. Sheets of high-purity tantalum (50 ppm Cb, <25 ppm Ti, 10 ppm Fe, 5 ppm Cr, <50 ppm Mo, W, and all other metals, 15-75 ppm O2, 10-30 ppm N2, and 10-30 ppm C) approximately 1/4 by 1/2 by 0.020 in. were heated to temperatures between 1800" and 2700°C in a carbon resistor furnace under an atmosphere of argon plus sufficient methane to maintain an excess of carbon at the sample surface. The thicknesses of the carbide layers, illustrated in Fig. 1, were measured with a filar micrometer and plotted logarithmically as a function of time. Fig. 2 is a typical plot for the TaC phase. The points may be represented within experimental error by lines with slope equal to 1/2; therefore the growth of the layers may be described by the usual expression X = kt1/2, where X is the layer thickness, t is the time, and k is a temperature-dependent constant. From these data and compositions at the phase boundaries, it is possible to estimate values for the diffusion coefficients of carbon in each phase, assuming that layer growth occurs by carbon diffusion alone, and that the dif-fusivity is not a function of composition within each

Jan 1, 1965

By M. G. Benz, J. F. Elliott

Otto Schaaber (Institut für Harterei-Technik, Bremen -Schönebeck, Germany)— Langenberg, Pestel, and Honeycutt gave an interesting example of the grain refining effect nonstationary magnetic fields may execute on a solidifying metal. Probably some additional comments, based on more than a decade of experience with this method of influencing crystallization, may be useful. They refer to an attempt to explain the mechanism of grain refinement by such fields, and to recent European developments which have not been mentioned in the paper. I. During studies of the temperature distribution in a metal body near the phase boundary solid/liquid, an anomaly was observed under certain special conditions: a) direction of heat transfer as horizontal as possible, b) steady state (equilibrium, i.e,, solidification resp. melting rate exactly zero). In the liquid phase, immediately adjacent to the phase boundary, the temperature was found to be constant over an appreciable distance in spite of a high value of heat transfer (40.000 to 70.000 keal/ m2h).3 Convection, which might explain this phenomenon, could not be observed. Therefore another explanation had to be sought. The assumption that a metallic melt, especially at temperatures near the point of solidification, contains some sort of atomic arrangement with a higher degree of order than the surrounding liquid, now is generally accepted. Considering the differences in energy between such an arrangement and its environs, a transport of heat even in absence of any temperature gradient is conceivable by continued formation and redissolution of regions with a higher degree of order, i.e., with lower energy level.3 At this stage, it was not necessary to postulate any special condition as to the form or size of these regions or the distance between arrangements to be newly formed and those to be redissolved. However, a simple consideration shows that an energy transfer from one region to another will only be possible without loss of energy, if the distance between will be equal to the lattice parameters, and if, secondly, crystallographic axis or planes will be parallel.4 By the way, this assumption might give a reasonable explanation of the well known orientation effect of the heat flow during solidification. Any measures to prevent columnar crystallization should act upon this ordering mechanism: a) the regions with a lower energy (higher order) should not be allowed to arrange themselves parallel to the direction of heat flow, and their growth should be disturbed; b) all conditions leading to an appreciable heat flow of uniform direction should be avoided or removed. Condition a) may be satisfied by a physical force preferably under 90 deg to the main axis of the columnar crystals (i.e., parallel to the solidification front) acting on the ordered regions; condition b) by equalizing any differences in

Jan 1, 1962

Copper ores from small mines in the area south of Tucson, where the Twin Buttes mine is located, were first operated in the 1880&apos;s. Today this area is one of the great copper mining centers of the world. In 1963, Anaconda Company acquired the property from Banner Mining Company and in recent years joined with AMAX in a 50/50 partnership to work the Twin Buttes property. From the beginning, Anaconda had relied on conveyors to remove overburden, oxide material for eventual leaching, and ore from the open pit. In the large st preproduction stripping program in mining history, Anaconda in a four-year period (1965 to 1969) removed 266 million tons of overburden of an average depth of 500 ft (152 m) lying over the ore body. The alluvium overburden was stripped by scrapers carrying 70 to 80 tons and push-loaded by two D9 tractors operating in tandem. The scrapers delivered their loads to bins which fed a 60 in. (1.52 m) conveyor having a capacity of 8500 tph. The 25% slope belt conveyor, which was 2100 ft (640 m) long, transported the material to the brow of the pit, where it was transferred to an 8300 ft (2530 m) surface belt to a 1000 ton loadout bin. At this point, the overburden was trucked to the sites of the tailings ponds, where it was used for dam construction. During 1976, the one billionth ton of overburden was removed from the Twin Buttes mine. The Twin Buttes quartz monzonite porphyry contains only scattered mineralization of which chalcopyrite is the most abundant mineral, associated with chalcocite, covellite, minor bornite, and several oxide minerals. Oxidation has progressed to variable depths of up to several hundred feet below the base of the alluvium. Because of the depth of the sulfide and oxide ores and hard rock waste, two in-pit crushers and conveyor systems were also installed for their transport out of the pit; and in 1976 a third crusher and conveyor system was installed lower in the pit for waste rock only. The two initial crushing and conveying systems were designed to handle any of three functions: crushing waste to be disposed of by a rail-mounted stacker -conveyor, crushing oxide ore for conveyor and then truck transport to stockpiles for future leaching, and primary crushing of sulfide ore for conveyor transport to the two 30 in. by 70 in. (0.76 by 1.78 m) secondary crushers and the two 7 ft (2. 13 m) standards and four 7 ft shortheads in the third and fourth stage crushing plant. A third standard crusher has been in- stalled recently. Mining is done by 15 yd (11.5 cum) shovels which load 100- and 150-ton

Jan 1, 1978

New York Meets first Wednesday after first Tuesday of each month. J. E. JOHNSON, JR., Chairman EDGAR RICHARD, Vice-Chairman D M LIDDELL Secretary, 7 Wall St.. New York. N. Y. C. A. BORN, Treasurer JOHN V. N. DORR LEWIS W. FRANCIS Boston Meets first Monday of each winter month. R. L. AGASSIZ, Chairman JAMES G. CARLETON. Vice-Chairman E. E. BUGBEE Secretary-Treasurer, Mass. Inst. of Technology, Cambridge, Mass. W. E. C. EUSTIS G. A. PACKARD Columbia Holds four sessions during year. Annual meeting in September or October. W. H. LINNEY, Chairman OSCAR LACHMUND, Vice-Chairman LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. STANLY A. EASTON S. SHEDD

Jan 12, 1917

C. W. GOODALE, * Butte, Mont.-In regard to the employment manager, the North Butte Mining Co. has undertaken that line of work and the rest of the companies are watching the experiment. If it is proved to be the proper thing, the system will be introduced into other mines. We have to combat the opposition to the use of the "rustling card. It is nothing more nor less than asking the nationality, where the plan formerly worked, and whether he is married or single. ROBERT RHEA GOODRICH, Anaconda, Mont. (written discussion?).¬Since the efficiency of the different phases of personnel work employed by industrial concerns, which are bringing about greater efficiency and lessening the labor turnover, the latter being intimately connected with "contentment of mind," depends on the individual workman, it is highly desirable, as far as industry is concerned, to keep the workman&apos;s mind and body in trim in order to lessen accidents and produce a higher grade of work. Prevention being better than cure, health supervision of the workmen during employment should be maintained by the employers in order that mental alertness and physical well-being may be obtained. I have long believed, from observation in many plants, that when any problem is dependent on the individual workman, what he believes and what he does is vitally dependent on his health. I will follow with much interest what is to be clone in the future in relation to the subject of health supervision during employment (as well as medical examinations at the time of employment), and I hope this idea will be generally instituted in personnel work. A workman with good health and a contented mind should be an ideal component of a progressive industrial concern. The contentment of the workman is fostered by a number of admirable phases of welfare work which are being still further developed. The mental and physical well-being of labor should be the issue in Labor vs. Capital in the new period of the industrial promotion of the United States into which we are now entering.

Jan 4, 1919

By Eugene McAuliffe

The term "mechanical mining" carries an ambiguity which justifies a preliminary word of explanation. . All mining activity conducted in this day is more or less mechanical; that is to say, power expressed in the form of electricity, steam or compressed air is used in some portion of practically every mining activity of consequence. "Mechanical loading" is more nearly correct than "mechanical mining" in reference to present practice. The first substantial effort made in the direction of mechanical mining, subsequent to the application of steam for hoisting and underground pumping purposes, was that of substituting for hand labor undercutting and shearing by power-driven machines. The undercutting of coal by hand represented at one time the most arduous task confronting the miner. Occupying a kneeling position in the thicker beds, or lying on his side in the thinner coal, the task was tedious and exhausting. The first attempt to substitute crude air-driven, and later electrically driven, "punchers," as the percussion type of machine was called, met with much the same opposition on the part of the workers as was expressed by workers in the other industries when any innovation, whether labor-saving or otherwise, was introduced. We should not be too critical of this attitude of mind shown by the mine workers. The peculiarly isolated character of the work carried on in semidarkness by a class of men who to a large extent lived and held themselves aloof from the other branches of society led long ago to the development of a craft consciousness which they have found difficult to surrender. It was not until 1891 that a definite record of the results obtained by the use of undercutting machines of all types was made available, the quantity undercut in that year totaling 6,211,732 tons of bituminous coal from all American mines. The volume of bituminous coal undercut by machines in 1928 totaled 369,687,007 tons, or 73.8 per cent. of the nation&apos;s production. In the light of this experience, we can properly feel that the work of introducing the coal-loading machine as a substitute for hand shoveling is making substantial progress.

Jan 1, 1931

By Charles R. Keyes

I. Introductory,.......... 185 II. Hypotheses oF the Origin of OzaRk Ores..... 186 1. General Considerations........ 186 2. Schmidt-Leonhard and Gage View...... 187 3. Jenney Opinion.......... 187 4. Posepny Idea,.......... 188 5. Winslow-Robertson Hypothesis....... 188 6. Branner Proposition......... 189 7. Keyes Statement.......... 189 8. Van Hise-Bain Theory........ 190 III. Requirements of an Adequate WoRking-Hypothesis,... 190 IV. GeneRal Geotectonics of the OzaRk Region.... 192 1. Salient Aspects.......... 192 2. Geologic Formations......... 192 3. Character of Faulting...192 4. Extent of Flexing......... 193 5. Unconformity Inequalities....195 6. Warping of Strata...195 V. Classes of Ore-Deposits... 196 VI. Vadose ORe-ConcentRation,........ 197 VII. GeogRaphic DistRibution of the Ore-Bodies,... 199 VIII. Relation of ORe-Deposit to Geologic Structure... 201 1. General Occurrence of Ore-Bodies in Basins.... 201 2. Deposits of the Central Missouri District..... 203 3. Deposits of the Southwestern Missouri District.... 203 4. Deposits of the Northern Arkansas District... 305 5. Deposits of the Southeastern Missouri District.... 206 6. Synclinal Ore-Deposits of Other Districts.....207 7. Significance of Ore-Troughs in Prospecting... 209 8. Origin of the so-called Synclines,...210 9. Significance of the Cross-Bars of Joplin..... 213 10. Relation of Ore-Run to Ancient Relief-Features,... 215 IX. Direction of GRound-Water Circulation..... 216 X. VeRtical Range of Workable Ore-Bodies,... 218 XI. Oscillation of Ground-WateR Level...... 219 XII. Relations of Ore-Bodies to Lithoclasic Features,.. 220 XIII. PRimaRy Source of Ore-Materials,...... 220 XIV. Zone of Ore-Enrichment,......... 222

Jan 1, 1910

By A. C. Emery

The physical and chemical properties for the metalliferrous feed materials to the Imperial Smelting Process blast furnace are defined and the means of achieving these properties by the sintering or briquetting routes discussed. Modern sinter plant performance data is included with a plant flow sheet showing draughting patterns. The necessity for ensuring an adequate SO2 content in sinter machine gases when roasting sulphide materials to enable conversion to sulphuric acid in a contact acid plant is described. The ability of the process to consume limited quantities of oxide materials, residues from other processes and other secondary sources is discussed. The argument for a briquetting route is developed out of this limitation and the merits of cold and hot briquetting examined. Development work on the hot briquetting route for this purpose is briefly described and several flow sheets outlining possible applications for hot briquetting to different raw material situations including the preparation of low lead charges for the furnace are presented.

Jan 1, 1977

By Earl Oliver

CONTENTS PAGE A.I.M.E. Stabilization Committee Activity 3 Definition of Capture Rule: Robert E. Hardwicke 4 Westmoreland Natural Gas Co. vs. DeWitt 5 Kelly vs. Ohio Oil Co 5 Bernard vs. Monongahela Gas Co 6 Definition of Ownership in Place 7 Prospective Stabilization Remedies 7 Dean Roscoe Pound&apos;s Four Tests of Practicability 7 I: Mechanically Feasible 8 Capture Rule 8 Ownership in Place 10 Mechanical Separation Method 10 Engineering Appraisal Method. 11 II. Economically Advisable. ., . 13 Capture Rule 14 Ownership in Place 14 III. Politically Wise 14 Capture Rule 14 Ownership in Place 17 IV. Legally Sound 18 Capture Rule 18 Ownership in Place 19 Dean Henry M. Bates&apos; Analysis 19 Resume 22 THE A.I.M.E. Stabilization Committee was named in 1932 to ascer-tain whether some practical substitute could be devised for the Rule of Capture, which was generally credited with being the major cause of instability in the Petroleum Industry. After considerable intercommittee correspondence a letter was received from. E. DeGolyer under date of Jan. 25, 1935, in which he discussed the possibility of modifying rather than discarding the Rule of Capture. He summarized his proposal as follows:

Jan 1, 1937

By M. L. Holzworth, Philip R. Sperry, Paul A. Beck

INTRODUCTION THE basic work of Z. Jeffries1,2,3 has long ago established the main features of grain growth in the presence of a dispersed second phase. Working with sintered specimens of initially fine grained tungsten, to which various amounts of thoria have been added, Jeffries found that grain growth was inhabited, that is, practically prevented, up to a certain annealing temperature. When this temperature, which increased with the thoria content, was exceeded, extremely large grains developed abruptly from the fine grained matrix. Such a "coarsening temperature" was later found by Gross mann13,14 in certain types of steel, while Bain showed" that in other steels grain growth was gradual, without inhibition and abrupt coarsening. Later work16,17,18,19,21 demonstrated the connection between coarsening and aluminum additions. The viewpoint that the direct cause of inhibition and coarsening in aluminum killed steels is a fine dispersion of aluminum oxide21 appears to be held quite generally, although some doubts have been voiced even very recently.20 In steels with Ti additions the titanium carbide phase is considered responsible for the inhibition effects found.20 The coarsening temperature increases, with the titanium content. That coarsening may occur, as a result of certain heat treatments, even in low carbon rimmed sheet steel, was shown by Samuels,22 He also detected coarsening in a steel ingot of similar composition, after giving it the same heat treatment as that used by him for the sheet material, In this instance the identity of the inhibiting phase has not been determined, However, Tangerding found 23 that even the few small carbide particles, which occur in carbonyl iron, have a very marked inhibitive effect. As a result of an oxidizing anneal at 850°C, large grains begin to form at the surface of the carbonyl iron specimen, and gradually grow inward as the subsurface oxidation of the carbide particles progresses and eliminates the obstruction, The carbide particles can be removed also by annealing in hydrogen, with similar results. But if the oxidizing anneal of 10 hr at 850°C in air, is followed by annealing in hydrogen for 75 hr at the same temperature, grain growth is more spectacular; usually the whole specimen is transformed into a single crystal (approx. 1,5 cm X 5 cm). The reversed procedure, that is, hydrogen annealing followed by oxidizing annealing leads to smaller grains. Tangerding arrived at the logical conclusion that there must have been in his specimens some additional obstruction to grain growth resulting from a minor impurity, other than carbon. It seems likely that this obstruction was caused by an oxide formed during the oxidizing anneal and gradually reduced during the subsequent hydrogen-annealing. Other instances of grain growth inhibition of varying severity, associated with a dispersed second phase, have been described by several authors. Notable examples: lead with 0.06 pct Cu or Ni,24 cartridge brass with 0.12 pct Cr,25 or with up to 0.15

Jan 1, 1948

By Paul D. Merica, R. G. Waltenberg

Although nickel was discovered and isolated as early as 1750 and its valuable properties recognized, many years passed before it was used commercially for wire, sheet, rods, etc., in the pure form. This was due partly to its high cost at that time and partly to the fact that it was not possible to refine and cast nickel into ingots sufficiently malleable to be amenable to the usual forging, rolling, or drawing processes. So remarkable was this fact, and so different from the experience at that time with metals such as copper and iron, that it has left its impress on the nomenclature within the nickel industry. To this day, furnace-cast nickel produced in such a manner as to be suitable for rolling and forging is called malleable nickel to distinguish it from the ordinary pig and shot nickel of commerce. In 1878, the firm of Jos. Wharton, of Philadelphia (which later became The American Nickel Works, a constituent of The International Nickel Co.) exhibited at the Paris Exhibition specimens of rolled pure nickel strip and of drawn nickel wire. About this time, there was considerable activity in the study of the refining of nickel and several methods were described, some of which were patented, for the production of furnace-cast malleable nickel including the use of manganese (Boed-dicker,1 Selve and Lotter2), the use of potassium permanganate (Berns-dorfer Metallwarenfabrik3) and the use of phosphorus (Garnier4). By far the most efficient method was discovered by Th. Fleitmann in 1879;5 it consisted in adding to the molten nickel, just before pouring the castings, from 0.05 to 0.125 per cent. of metallic magnesium. This soon became the recognized final malleableizing treatment for furnace-cast nickel.

Jan 1, 1925

By M. R. J. Wyllie

Eight laboratory-prepared aqueous base drilling muds representing common mud types, and 15 aqueous base drilling muds sampled in the field, have been used in an experimental investigation of the relationship between the streaming potential developed across a mud filter cake and the differential pressure causing filtrate flow. It has been established that the relationship is of the form, ES = kPy, where Es is the streaming potential, P the differential pressure and k and y are constants for any particular mud system at constant temperature. Beyond a certain minimum thickness this relationship is independent of filter cake thickness. Experiment has shown that both k and y are temperature dependent parameters and that in certain mud systems there is a critical value of P above which the simple relationship Es = kPY ceases to hold. The constant k tends to be a function of the mud resistivity at 77ºF, but the exponent y has not been found to be related to any commonly measured mud property. Certain field experiments are described which serve to demonstrate that the total SP (self potential) developed opposite a formation may be quantitatively accounted for as the algebraic sum of an electrochemical potential and an electrokinetic potential. A chart to permit the simple use of mean solution activities in the interpretation of electrochemical SP data is given and its use described. Various field methods for computing the electrokinetic SP component of the total SP are considered and rejected as being unduly complicated and inaccurate. It is shown that the employment of low resistivity drilling muds is essential if optimum accuracy is desired in the use of the S.P. curve for the purpose of computing connate water salinities by the electrochemical SP method. The use of such low resistivity drilling muds is accordingly recommended. INTRODUCTION In a previous paper&apos; a quantitative analysis of the electrochemical compovent of the SP (self potential) curve was made and it was shown that the electrochemical* emf, E, could be expressed as E = ZtRT/F In a,/a,, where t is the transference number of the chloride ion, R is the gas constant, T the absolute temperature of the formation water and mud, a, the mean activity of the connate water (assumed to be sodium chloride) and a, the mean activity of the mud (as sodium chloride). The essential accuracy of this expression was confirmed by an investigation 2 of the SP kicks opposite sands of known water salinity. The logs examined had been routine runs in oil wells in a number of Mid-Continent states. Further confirmation of the original analysis of the electrochemical SP is implicit in the paper by Tixier3 wherein a relationship between the SP and the ratio of connate water and mud resistivities, based only on field data, is given. Allowing for the fact that mud and connate water resistivities were used instead of activities, and that electrokinetic effects were ignored, the constant reported by Tixier is essentially 2tRT/F. The error involved in the universal substitution of resistivities for activities will receive further reference below. Possible reasons for the fact that the electrochemical properties of shales do not appear to be significantly dependent upon either the nature or the quantity of cation exchange materials, such as clays, they contain has been considered at some length by Wyllie and Patnode.4 In the same paper, the probable effects of shale thickness and compaction on electrochemical efficiency, and hence the inherent difficulty of obtaining reliable laboratory-scale data, were also pointed out. However, it is

Jan 1, 1951

By R. Laird Auchmuty

The A. I. M. E. Subcommittee on Bituminous Mining has been trying for several years to secure the information that was collected by the Marquette Cement Manufacturing &. on the subsidence of its property caused by mining coal beneath it. The Marquette company was willing to have these data used, but it was impossible to obtain them because the records had been filed away. About two years ago these records became available and the engineering data presented herewith were compiled from them by R. L. Auchmuty, assisted by L. E. Young, who was connected with the collection of the information. On account of the cost, it is impossible to reproduce all of the data here, although the original information is on file with the records of the Committee on Ground Movement and Subsidence. The accompanying charts show representative and average data and give only the engineering information with enough description to tell how it was obtained. It is hoped that all of those connected with the original case will participate in the discussion that this will bring forth. Howard N. Eavenson, Chairman, Subcommittee on Bituminous Coal Mining. PRobably the most complete records of subsidence due to coal mining in the United States are those compiled by the Marquette Cement Manufacturing Co. at LaSalle, 111. These records, covering a period of more than three years, were compiled and used as evidence during the suit of the Marquette Cement Manufacturing Co. vs. the Oglesby Coal Co. at Oglesby, LaSalle County, Ill., in which the cement company successfully endeavored to stop the coal company from mining under its property. Fig. 1 shows a typical section of the geological formation. The cement company was mining the LaSalle limestone which lies about 125 ft. under the surface. The limestone is 30 to 35 ft. thick and underlain by about 15 ft. of shale. The cement company was mining about 20 ft. of the limestone, and in some places 10 to 12 ft. of the underlying shale, by the room and pillar method. The mining of the limestone always preceded the mining of the shale. The coal company was mining by longwall advance methods the NO. 2 seam of coal 42 in. thick underlying the limestone bed by 435 to 470 ft. The coal mine, a very old one, had largely mined out its original property

Jan 1, 1931

By Spencer S. Shannon

The lanthanide elements from lanthanum (atomic number 57) to lutetium (71) plus yttrium (39) are called the rare-earth elements; scandium (21) is chemically similar to yttrium and the lanthanides, but differs in occurrence. The rare-earth metals were divided into three categories by the chemist, Berzelius, in the early 1800s; however, modern usage defines only two groups. The cerium group is named after the most abundant -element and comprises lanthanum (57), cerium (58), praseodymium (59), neodymium (60), promethium (61), samarium (62), europium (63), and gadolinium (64). Traces of natural promethium were discovered in apatite in Finland (Erametsa, 1965). The yttrium group, also named after its most abundant representative, comprises terbium (65), dysprosium (66), holmium (67), erbium (68), thulium (69), ytterbium (70), and lutetium (71). Yttrium most closely resembles holmium in chemical properties, and occurs most commonly with the heavy lanthanides. The rare-earth minerals may be divided into cerium-group, yttrium-group, or mixed-group classes. A number of rare-earth minerals contain thorium and uranium, but these are variable in content and are not essential to the composition of the minerals. In monazite, a mineral that is a principal source of rare earths, the worldwide average content of thorium oxide is 7.2 % ; however, varieties of monazite contain as little as 0.001% and as much as 31.5% thoria. Monazite is the chief ore of thorium and, until recently, thorium has been the main product; the rare-earth metals were in fact byproducts. However, because of the great demand for rare-earth metals by the petroleum refining and the iron and steel industries since the early 1970s, the roles have been reversed so that thorium is now the byproduct. Uses A 9 to 1 mixture of yttrium and thorium oxides is used for high-intensity incandescent lamps and for high-temperature-resistant windows and lenses. Yttrium oxysulfide and orthovanadate, doped with europium oxide, are used in color television tube phosphors. Yttrium, as well as cerium, praseodymium, and samarium, is alloyed with cobalt to form strong permanent magnets. It hardens magnesium alloys and retards the oxidation of iron-chromium alloys. Yttrium-iron garnets are used for transmitting low microwave frequencies. Yttrium-aluminum garnets are used as host crystals for lasers and as artificial gems. Yttria also forms strong, stable, high-temperature refractories. Gadolinium-gallium garnets are used in substrate wafers on which bubble-memory films are deposited. Rare-earth chlorides, particularly of lanthanum, neodymium, and praseodymium, are used as catalysts for petroleum cracking. Mischmetal is used for lighter flints and to improve the ductility and impact strength of iron and steel alloys. Mischmetal also reduces the fatigue resistance of magnesium and aluminum alloys. Rare-earth oxides are used for polishing glasses and lenses. Individual or specific combinations of high-purity oxides are used as additives in glass to maintain or change its color, dispersion, or refractive index. High-purity oxide combinations are also used to color tile and to opacify porcelain enamel. Rare-earth fluorides and oxides are used in carbon-arc electrodes to provide incandescent white light. Lanthanum or gadolinium oxysulfide phosphors, activated with terbium, are used as x-ray screen intensifiers. Hydrogen can be stored by sorption on lanthanum-nickel alloys (Anon., 1979). Thorium232 is bombarded with slow neutrons in breeder reactors to create fissionable thorium233 for nuclear fuel cells. The 330-MW, high-temperature gas-cooled reactor at Fort St.

Jan 1, 1983

By D. J. Coolidge, H. L. Sheakley

This paper does not deal with all sands used in the glass industry in Missouri; it covers only that used in the plate-glass factory at Crystal City. However, it is probably safe to say that other sands, pro- duced throughout the state for this purpose, are of identical nature. The glass sand used in Missouri is cornrnonly called the St. Peter deposit, which is ascribed to the Ordovician Rock series in the form of sandstone. This St. Peter deposit, aside from a few small outliers, covers a large area of eastern Missouri. It forms, through a broad curve, the northeast margin of the typical Ozark region between Cape Girardeau on the southeast and Mineola, Montgomery County, on the northwest. The belt is extremely irregular, varying from one to ten miles in width; its length is 150 miles in a straight line. The outcrop near the entrance to the Crystal City mine appears in the form of a sandstone bluff approximately 30 ft. high, running along Plattin Creek (Fig. I). Above the sand rock an overburden of Joachim limestone appears, which thickens to nearly 300 ft. and forms the hill commonly called Buck Knob. Test holes where drilled at various points and the drillers&apos; log indicate that the St. Peter deposit ranges in thickness from 63 to 71 feet. Properties of the St. Peter Sand From an analysis of the glass sands of the St. Peter formation in Missouri, the follow-

Jan 1, 1948

By C. E. Shoenfelt, D. E. Winchester

NO important discoveries of petroleum during 1933 were reported from New Mexico. Lea and Eddy counties were the centers of activity during the drilling season and each had a number of interesting completions. The Hobbs pool, in Lea County, was definitely outlined on the east, north and northwest. Under an agreement reached last summer by state officials and operators, the Hobbs pool was continued under proration throughout the year. One hundred eighty-four units of 40 acres each were being produced at the end of 1933. The allowable was 21,306 bbl. daily at the beginning of 1933, but when the agreement was revised in the spring the minimum was raised to 30,000 bbl., and by the end of the year had been raised to 33,473 bbl. At present the field is being prorated on the basis of 25 per cent on acreage and 75 per cent on potentials except in the southwestern edge of the field, where water encroachment is a problem. In this area the basis of proration is 40 per cent on acreage and 60 per cent on potentials. A corrective method employed in this part of the field has been partly successful. The water is advancing in the upper part of the pay, a dolomitic limestone, and in a number of instances packers have been set in the pay below the water and above the oil. The locating of a satisfactory seat for a packer is difficult and in some instances has not been a complete success. Pipe line runs from the field during the year aggregated 11,413,218 bbl., bringing the total gross production up to 41,093,681 bbl., of which 39,000,-000 bbl. has been produced under proration, which went into effect on July 10, 1930. On Nov. 30, potentials were determined on the assigned pressure basis and the total was reduced 71,165 bbl. daily, to 1,265,-332 barrels. The outstanding completions in the Hobbs pool were three in number, of which the best was the Humble Oil & Refining Company&apos;s No. 3B Bowers in sec. 20, 18S., 38E., with an initial production of 11,664 bbl. of oil and 10,000,000 cu. ft. of gas. The Shell Petroleum Company&apos;s No. 4B McKinley, in the same section, produced at the rate of 22,940 bbl. of oil while flowing open, but when tubed, flowed at the rate of 6610 bbl. The third outstanding well, No. 4 Hardin of the Tidal Oil Co., and located in

Jan 1, 1934

By V. C. Allen

THE Tri-State Zinc, Inc., Galena, Ill., was confronted with the problem of securing ore from a deposit because the hoisting shaft was several thousand feet from the mill. The orebody is several thousand feet long, averaging 200 ft in width and 60 ft in height and opened up by vertical shafts some 300 ft deep. Mining is by the room-and-pillar method. During the initial operation the ore was loaded by conventional electric 1/2 -yd boom-and-dipper shovels and hauled to the shaft by 8-ton diesel trucks. This underground ore loading and hauling was well adapted to the conditions and productive of low costs per ton. However, with the mill situated as mentioned, a triple handling of all broken rock was necessary: 1-from the stope to the shaft by truck, 2-up the shaft by skip or can into the surface hopper, and 3-by truck from the surface hopper to the crushing plant at the mill. In addition to the repeated handling, serious troubles were encountered during the winter because of freezing in the shaft hopper.

Jan 6, 1951

By Gail F. Moulton, C. E. Shoenfelt

Proven and developed oil reserves, and productive capacity increased during 1943 in the fieids of the Rocky Mountain region. Oil production during the year was nearly 45 million barrels, or slightly less than in 1942. The rate of production at the start of 1944 was slightly less than at the start of 1943. Pipe-line projects scheduled for completion during 1944 should permit a substantial increase in the rate of production. Wildcat exploration was more extensive in Montana during 1943 than in other states in the region. The results of wildcat drilling were unsatisfactory, although new oil fields were discovered on the Gebo, Little Buffalo Basin and Steamboat Butte structures of Wyoming, the Gage anticline of Montana, and the Clark Lake structure of Colorado. The area of the structures on which the discovery wells were drilled is known to be considerable, but further drilling is required to determine the importance of these fields. The most important increase in proven reserves resulted from the drilling to newly discovered deeper producing formations in the Elk Basin and other fields of the Big Horn Basin area of northern Wyoming. Lack of a market and unfavorable prices for heavy black oils had prevented complete exploration of favorable areas in the Rocky Mountain region for many years. In particular, the effect on further exploitation of the Big Horn Basin area had been quite serious. The increased demands for all oils created by the war and an increase in price in February 1943, combined later with Government approval of construction of pipe lines from the Big Horn Basin area to the Billings and the Casper districts, provided a basis for undertaking a drilling program. The important additions to reserves were made by drilling in previously discovered fields. The newly discovered fields resulted from drilling on favorable structures which had been known for several years. A continuation of the favorable results obtained during 1943 seems possible only if further testing of the newly discovered fields is satisfactory and if drilling on less favorable known structures or geophysical prospects results in the discovery of new fields. The amount of drilling in the Rocky Mountain states of Colorado, Montana and Wyoming, was about the same during 1943 as .in 1942. However, owing to the fact that a number of wells of large potential production were completed in the Elk Basin field, the total initial production of the prodicing wells was- nearly twice as great for 1943 as for 1942. Explorational activity at the end of 1943 seemed to be directed to geophysical methods, which are required to discover structures hidden beneath the rocks of Tertiary age in the Powder River and other large sedimentary basins. It is in

Jan 1, 1944

Jan 1, 1920