Search Documents

By Andrew Hyslop

In our never ending search for new and better ways of underground mining, we find that transportation has had its share of new ideas in the past few years. The old and still effective method of track haulage has had some competition from rubber-tired cars and belt conveyors, each of which has its own safety hazards which demand close scrutiny in any safety study. The use of shuttle cars, in particular, has introduced clearance hazards caused by the absence of the more or less positive guides formed by the rails of a track sys- tem; likewise the requirement of greater clearance tends to increase roof hazards which we all know to be great enough with the best of methods. However, the subject of transportation hazards is too broad to be covered entirely in one paper, so I will confine myself to track methods which carry the preponderance of underground tonnage. I am quite sure that to this group it is an evident fact that haulage accidents are of major importance. However, to stress the point, it may be well to look at a few figures. Safety statistics can be quite boring and often are subject to question as to mathematical accuracy because of different

Jan 1, 1949

By Peter N. Blakey, Thiann R. Yu, Douglas O. Tansey

A flexible, efficient, and relatively low-cost drilling and blasting operation has evolved at Texasgulf Canada, Ltd.'s Kidd Creek underground mine. Located 32 km (20 miles) north of historic Timmins, Ontario, the underground operation utilizes a sublevel open stoping method developed with large-diameter blastholes. Over the years, Kidd Creek engineers have experimented with various drill-and-blast techniques, leading to the present-day practice. Continuing work is being conducted to further mechanize the blasting operation.

Jan 6, 1976

By C. M. Nickerson

IT is apparent that repressuring of the oil measures is becoming increasingly important to the oil industry, and is a matter that warrants the best efforts of the petroleum engineer charged with applying this method of operation to a producing property. Considerable attention has. been directed to repressuring in various California oil fields, such as Dominguez and Seal Beach, which have served to sell the more progressive operator on this idea and also to keep him sold. The projects that have received most attention are in comparatively young fields where the fluid levels are high, the wells, perhaps, still flowing, where the wet gas production is of considerable volume, and where there is vital need of immediate conservation of gas, which otherwise would be blown to the air. The new State of California Gas Law, which prohibits the waste of gas, has served to interest the oil industry in -means of conserving the gas that is now being blown to the air because of lack of markets. This vitally affects the operator in the older, well-depleted oil fields of the state, because in many cases he has a limited market for gas, on account of the flush production from the more active oil fields. While the waste of gas is relatively small in these older fields, such as the Midway-Sunset area, it now attains considerable importance, since under the new State Gas Law it must be put to some beneficial use. Repressuring in the older fields of California has not received the attention of the petroleum engineers that is warranted by the present situation. This paper was prepared with the view of presenting the salient features connected with repressuring in the well-depleted oil measures of the older fields, and to show what results have already been obtained in these fields by injecting the unmarketable. gas into the sands, particularly in the Midway-Sunset field in the San Joaquin Valley of California. Other projects in the older fields of the state offer some supporting data in this connection, such as the Shields Canyon and the Brea Canyon fields.

Jan 1, 1929

By G. W. Preckshot, N. G. DeLisle, C. E. Cottrell, D. L. Katz

MOST crude oils contain asphaltic substances that may be naturally or artificially precipitated. In the Greeley field, California, this asphaltic bitumen is precipitated during the flow of the oil from the reservoir to the stock tank. The mechanism of such precipitation is not well understood. This paper presents the progress that has been made by using the electron microscope as a new tool and by observing the effects of the streaming potential on the formation of bitumen particles. Crude oils at atmospheric pressure viewed in the electron microscope in very thin films under a vacuum showed no asphaltic particles. A technique of preparing slides of thin films by dilution of the oil with benzene and washing in petroleum ether was used at first, and these observations showed that the solvents caused the formation of the particles, varying from 0.01 to 0.2 micron in diameter. The electrical effects of fluids flowing through porous solid were studied, with emphasis on the formation of colloidal particles by the streaming potential. The streaming potential of crude oil flowing through sand was measured and was shown to be responsible for the formation of bitumen particles. These results bring out a new phenomenon, which may occur when crude oil flows through the porous oil reservoir.

Jan 1, 1942

By Anal J. Mehta, Theodore D. Tiemann

Growing demand for steel and increasing dependence upon foreign ore makes the need for developing the technology for treatment of low-grade iron ores greater than ever before• Representative of these added interests were the studies carried on at the University of Wisconsin• These studies included among others: anionic and cationic flotation, magnetic separation, roasting followed by magnetic separation, electrostatic separation, a hydrogen reduction process,6,7 and caustic digestion• The idea of removing silica by caustic extraction is not new•-1; The principle of concentrating siliceous iron ores by this method is based on the fact that silica is soluble in sodium hydroxide solution while iron oxides are essentially insoluble• For this process to be economically feasible, it is believed that some method of recovering silica from solution as a marketable by-product, with recycling of spent liquor is necessary. Precipitation of silica with carbon dioxide will allow subsequent causticizing of the spent liquor with lime• Caustic thus produced can be recycled for digestion• A flowsheet of the envisioned process is given in [Fig• 1] The purpose of this paper is to describe results obtained from the investigation of carbon dioxide precipitation of silica from sodium silicate solutions, which could be later applied to the caustic extraction process to treat low grade siliceous iron ores, particularly taconites.15 Theoretical Considerations The soluble silicates of sodium include sodium orthosilicate (2Na2O•SiO2), sodium metasilicate (Na20•SiO2), sodium disilicate (Na1O•2SiO2), and more highly siliceous products approaching Na2O•4SiO2• These materials have been described in detail by Vail•16 Stones has reported that the extraction of silica is not significantly affected by the amount of silica in solution until the Si02/Na20 ratio exceeds that of orthosilicate (Ratio = 1/2)• However, as the Si02/Na2O ratio exceeds that of metasilicate (Ratio = 1), silica extraction is significantly impaired• The present experimental work was confined to orthosilicate and metasilicate solutions, as to be successful the envisioned commercial process for the extraction of silica from siliceous iron ores would operate in this region. The mechanism of extraction of silica from aqueous sodium silicate solutions is complex in nature. For the carbon dioxide process-18 of core and mold making in which silica is also precipitated from sodium silicate solutions by gassing with carbon dioxide, the reaction of aqueous silicates with gaseous carbon dioxide has been represented by the equations: [ ] However, these equations are very much oversimplified• It has been shown that the reaction between aqueous sodium silicates and carbon dioxide gas is ionic in nature 18 Considering this fact and the mechanism for digestion of silica in aqueous sodium hydroxide, the overall conversion of aqueous sodium silicates to solid silica may be represented in ionic form by the following equations: [ ] Silicon in the silicate ion is shown here with a coordination number of 6• This may be in doubt, but it is known that ion (SiF°)-2 exists; it seems logical that the Si (OH) e 2 ion should be equally capable of existence•

Jan 1, 1977

By B. E. Mix, L. M. Barker

THe present methods of unloading ore and coarse-crushing at the Magna plant of the Utah Copper Co. are the developments of the pas five years. Hand dumping and breaking have given way to the rotary car dump and large gyratory; and the bucket elevators and stationary screens have been replaced by conveyors and shaking screens. The coarse-crushing plant may be broadly divided into two units the primary crushing and the secondary crushing, or primary roll, unit The former was erected in 1923; with the exception of the excavation the construction was carried on by forces of the company. Excavation was started in the middle of March, the first concrete was poured July 16, erection of the steel building started Oct. 30, and the unit was com pleted and operating Dec. 30. The unit has a capacity of over 24,001 tons of ore per day, and cost more than a million dollars. Remodeling of the primary-roll unit extended over a period of years preceding this some of the work having been done as early as 1918. Delivery of Ore from Mine, Yard Storage, and Handling Ori Cars to and from Primary Crushing Plant The ore is transported, in steel cars of 80 tons capacity, from the min' to the mill, where a reserve tonnage of loaded cars is maintained. Malle locomotives, handling trains of 45 cars, or approximately 3600 tons o ore per train, deliver the trains to a storage yard which contains thre tracks—a passing track and two storage tracks. All of this trackage i equipped with an overhead trolley system, so that electric locomotive can be used in yard switching. The storage tracks have a total length of 4500 ft. and provide storag space for 140 cars. The passing track, besides permitting switchin room for locomotives, is used for storage purposes between train arrivals thus giving intermittently a total storage capacity for the yard of approxi mately 200 cars. The amount of ore stored at any one time, howeve

Jan 1, 1926

By A. L. Holley

The members of the society are doubtless aware that the production of American Bessemer steel works is constantly increasing; that the same converters and machinery are doing more work every year. This enlarged output is due to various causes, chiefly the following: 1st. Better organization—better knowledge on the part of both managers and men, of the plant and the process; of the way to economize the more exhausting labor, and of the arrangement of the details of labor and operations so that they shall not conflict; also, more pluck—a greater willingness to take risks, or, more properly, such an intimate knowledge of the nature and capacities of the refractory linings in various stages of disrepair, and the probable be- . havior of the fluid metal at various stages of its treatment, that the precise nature of the risk may be better known, so that the works may be crowded to their full capacity. In the early practice, after getting four or five consecutive heats in a day, the men preferred to " let well enough alone," and to devote the remaining time to preparation for another turn. Now, thirty, and sometimes forty heats are regularly made during the twenty-four hours, day after day, without the frequent occurrence and without the fear of breakdowns or " messes," as the spilling of steel charges was graphically named in Sheffield. 2d. Although no new refractory materials have been developed, improved means of preparing such as we have, and of imbedding

By Nicholas J. Grant, Oliver Preston

A series of dilute solid solutions of a1uminum and silicon in copper, in powder -form, were internally oxidized, compacted, and extruded, to produce Cu-A12O3 and Cu-SiO2 alloys with 0.1 to 12 vol pct of oxide. Room-temperature tensile tests, creep-rupture tests from 450oto 850°C. conductivity measurements, and recrys-tallzzation studies were made. Oxide particle size and interparticle spacings were determined in an effort to relate the structure to measured strength values by means of known dispersion strengthening theories. A new dispersion strengthening theory, based on the effect of the dispersed phase on the retention of strain energy from the deformation step, zs proposed for this type of alloy, THE study of dispersion strengthening is of partitular interest in high-temperature materials technology in view of the excellent creep-rupture Properties and thermal stability achieved with SAP.1-5 Considerable effort has been devoted to this study in recent years, and encouraging results have been obtained in a number of systems.6 In general, the most

Jan 1, 1962

By P. Barnes

(Read at the Wilkes-Barre Meeting, May, 1877.) THE tabular statement accompanying this note shows the money cost in each of the three departments of manufacture, of 17 leading items, and also the proportion (expressed in a decimal fraction) which each of these items bears to the total cost. The statement can hardly be taken for more than an average illustration of the clear showing of ratios and of results which may be made by such an arrangement, for not only will these items vary from month to month in any given works, but the methods themselves of manufacture differ widely in different works. It is obvious that such a statement, however useful it may be, must be submitted with but exceedingly little explanation or discussion, or with none at all, for the reason that to enter at any satisfac-

Jan 1, 1878

By Frank J. Markewicz, William Lodding

Greensand, greensand marl, and green earth are names given to sediments rich in the bluish green to greenish black mineral known as glauconite by the mineralogist. The word glauconite is from the Greek word glaukos, meaning bluish green. The term "greensand" as a rock name for a glauconite-bearing sediment is more appropriate than "greensand marl," a term that has been doggedly perpetuated in the literature. Because of its potash and phosphate content, greensand was dug and marketed as a fertilizer and soil conditioner for more than 100 years. The advent of prepared fertilizers with adjustable nutrient ratios led to the decline of green- sand for agricultural application. The material has since been recognized for use in water treatment. Unfortunately, in spite of large reserves and worldwide distribution, the mineral has not been utilized to any significant commercial extent because no major application has been found for a substance with its chemical composition and properties. This lack is probably due to a paucity of research on its potential commercial application. Extraction of potash received considerable attention during and just after World War I. Because of relatively high extraction costs and generally low potash content (up to 8%), glauconite lost its appeal as a source of this commodity. Historical Background Greensand was used as a fertilizer in New Jersey in the latter part of the 1700s. During the early 1800s its use became more common; applications of up to 100 tons per acre were sometimes made, although recommendations for agricultural use suggested 20 to 50 tons per acre (Tedrow, 1957). Many crops, especially the forage type, were said to improve with greensand application; however, because of slow release of potash, large quantities were required. Certain greensands that contain sulfur and sulfide minerals are harmful to plant growth, and these were classified as "poison," "burning," or "black marls." The availability of higher-grade potash salts from other mineral sources, and the manufacture of prepared fertilizers, displaced the agricultural use of green- sand during the later 1800s. During the mid-1800s the domestic greensand industry, centered in a small section of the eastern United States, grossed more than $500,000 per year. Toward the end of the century, annual production had dwindled to less than $100,000. By 1910 there were only six or eight greensand producers, grossing less than $5000 (Tyler, 1934). There was a small revival in the industry during World War I because of the curtailment of foreign potash, especially from Germany. During the later 1940s and early 1950s greensand was again recommended as a food nutrient for plants and farm crops. Agronomic studies discussed its potential as a soil additive that gradually releases potash and many trace- element nutrients essential for plant growth (Tedrow, 1957). Greensand was sold with the idea that it would condition soil and absorb and hold water while its base-exchange properties would release trace elements. For a short time glauconite was utilized in certain parts of New Jersey as a binding additive in the brick industry, and in the 1800s for making green glass (Cook, 1868). In the early 1900s the base-exchange property of glauconite was recognized for water treatment, and the mineral gained acceptance as a water softener. Mansfield ( 1922) does not mention base-exchange; however, the base ex-

Jan 1, 1975

By Dale A. Vaughan, Oliver M. Stewart, Charles M. Schwartz

A. U. Seybolt (General Electric Research Laboratory)—The authors should be commended for adding some important information to our knowledge of the solubility of interstitial elements in metals. It is becoming increasingly evident that the effect of even traces of such elements have very far-reaching effects upon the mechanical properties of the body centered cubic metals. Those who have worked in this area know that the accurate determination of the small solid solubility limits in systems of the type reported by the authors is a quite difficult task, and it is therefore not surprising that frequently the results of different workers are not in agreement. It is instructive, and usually helpful, to plot the solubility results on log weight or atomic percent -1/T coordinates to find out if a straight line is obtained. A straight line is expected because in systems displaying solubilities of the order of 1 to 3 at. pet or less, Henry's law is usually obeyed—or at least well enough obeyed so that the deviation from linearity is not very appreciable. If Henry's law is obeyed, one canthen use the Van't Hoff Equation in the form In N = ?H/RT + C, where N is mole fraction, at. pet, or wt pet for small values, and AH is the partial molal heat of solution of the solute. R and T have the usual significance, and C is an integration constant. If one plots the reported nitrogen solubility values as indicated above, the three points fall reasonably well on a straight line. The oxygen values for the two upper temperatures fall very closely to the nitrogen values as shown in the authors' Fig. 15. However, the value at 500°C departs widely from the straight line established by the data at 1500" and 1000°C. It is, of course, true that one cannot place too much emphasis on the significance of a line established by only three points, but in the absence of reasons for anticipating deviations, data exhibiting wide departures from linearity should at least be examined closely. Fig. 16 shows the log at. pct -1/T plots for the authors Ta-O and Ta-Ndata including a solid circle point at 500°C and 1.8 at. pet for Ta-O, which is simply extrapolated from the two higher temperature points. In addition, the data of R. P. Elliott9 for Nb-O are shown. These points were picked off his curve and are not very exact, but as can be seen they line up well on a straight line. It is interesting, and probably significant, that the slope of Elliott's results is not far from those of Vaughn, et al. This is probably to be expected because one would anticipate that the partial molal heats of solution of oxyten in these two very similar metals should be not too far apart. AH for Ta-O is about -1900 cal per mol, while for Nb-O it is near -2300 cal per mol. Hence, this lends some support to the thesis that the point at 500°C for Ta-O is much too high. The data of Gebhardt and Preisedanz10 are also plotted, and it is seen that their data while lying on a linear plot, have an appreciably steeper slope. The possible reasons for this will not be discussed here except to point out that their pressure-composition data show anomalies which suggest that they may have been dealing with a different equilibrium from that being discussed. There is another consideration which would also suggest that the solubility at 500°C is lower than shown. The solubility values were obtained by the classic method of first establishing a lattice parameter-composition curve. This the authors did, and there is probably little doubt that it is quite accurate. Such a plot is generally almost error-free because it has a self-correcting feature in that any deviation from linearity makes a data point immediately suspect, and subject to confirmation. Unfortunately, this is not true with respect to the actual solubility values. These are obtained ordinarily by taking an alloy containing more solute than is soluble at some temperature and then thermally

Jan 1, 1962

By Ihor A. Kunasz

Lithium minerals occur predominantly in pegmatites which contain mineral assemblages derived from the crystallization of postmagmatic fluids or from the metasomatic action by residual pegmatitic fluids. They have been the traditional sources of raw materials for ceramic and chemical industries. However, with the discovery of Searles Lake, brines became new sources of lithium. Indeed, the 1960s may well be referred to as the "brine decade" because several brine bodies of significant economic importance were discovered. In the United States, the brines of Clayton Valley, Nevada, presently exploited by Foote Mineral Co., and the Great Salt Lake of Utah, to be exploited by the Great Salt Lake Chemicals Corp., have been defined as major sources of lithium. Also a lithium-bearing brine has been discovered in Chile. Following the termination of the AEC purchase program in 1959, several companies such as Maywood Chemical Co., American Lithium Chemicals, and Quebec Lithium Corp. were forced to close down their operations. Nevertheless, with the development of new applications in glass ceramics, air conditioning systems, synthetic rubber, and metallurgy (aluminum potlines), the lithium industry grew steadily, and with the potential application of lithium metal in batteries and nuclear reactors, a healthy growth can be foreseen. New products and new applications are likely to stimulate exploration for expanded reserves as well as the search for new sources from which lithium could be extracted economically. Geochemistry of Lithium Lithium is the third element in the periodic table. It is the lightest of all the metals, having an atomic weight of 6.938. Its ionic radius is 0.60A and its charge is + 1. The geochemistry of lithium has been extensively studied and has been summarized by Rankama and Sahama (1950), Goldschmidt (1937), and Hortsman (1957). The distribution of lithium in igneous rocks is controlled by its size and its charge, and by the (MgO+FeO)/Li2O ratio. In the early stages of crystallization of a magma, that ratio is very large. Consequently, both magnesium and iron are removed by ferromagnesian minerals in preference to lithium which is then concentrated in the residual magma. This results in an enrichment of lithium in silicic rocks and pegmatites (Strock, 1936). Pegmatites are coarse-grained igneous rocks formed by the crystallization of postmagmatic fluids. Minerals within pegmatites may also form by metasomatism (Jahns. 1955). Genetically, the pegmatites are associated kith neigh- boring intrusives. Mineralogically, granitic pegmatites contain feldspar, quartz, and mica as the main constituents and a variety of exotic elements such as lithium, beryllium, tantalum, tin, and cesium, which may or may not occur in economically significant concentrations. Detailed studies by numerous investigators (Cameron et al., 1949, 1954; Hanley et al., 1950; Jahns, 1953, 1955; Page et al., 1953) indicate that pegmatites often exhibit an internal zonal arrangement, with each zone containing a specific suite of minerals. The lithium minerals are usually found in the intermediate zones, and although as many as 13 zones have been recognized by Cameron, a complete zonal arrangement is rarely found. Zoning of pegmatite bodies has also been observed on a regional basis. The regionally zoned pegmatite sequences exhibit mineral assemblages and complexity according to their respective distance from the granitic bodies to which they are genetically related (Mulligan, 1965). Lithium is also found in small proportions in a variety of rocks. The average lithium

Jan 1, 1975

By John E. Latz

QUICKSAND far below the surface, stopped two attempts by the Potash Co. of America to sink a third shaft to a potash bed that lies 1000 ft below the southern New Mexico desert. Virtually all methods of grouting were employed in the two failures without any indication of consolidation of the flowing sand. Sinking the South Shaft at the Carlsbad potash mine seemed an almost insurmountable task, until freezing was employed as a final resort. This process that proved to be the answer may be defined as "the sinking of a shaft by freezing, consists of the formation, in the water-bearing strata, of a large block of frozen ground in which it is possible to sink a shaft without danger of an influx of water, providing the ice-wall between the water outside and the shaft itself is strong enough to resist the hydrostatic pressure." Freezing Method Used Extensively in Europe Successful frozen ground shaft sinking projects had been completed in Europe, and Russel G. Haworth, resident manager of the Potash Co. of America, went abroad in search of the know-how needed for the New Mexico undertaking. The freezing process, with a history of two failures at the time, was first successfully employed by Poetsch in 1885 at the Houssu Collieries near Haine St. Pierre, Belgium. Poetsch contracted to sink the remaining 64 ft of an uncompleted shaft through water laden strata from a depth of 190 ft to a depth of 254 ft. This work was in progress until 1887. The freezing and sinking consumed more than two years. As a result of early failures, the process was not favorably received until soon after the turn of the century. The accurate prediction of success in a given application was made possible by the concerted effort and study of a group of European engineers. Means of accurate deviation measurement and control were devised, the nature and properties of frozen water laden soil (the ice wall) were investigated, a thorough and rational basis of refrigeration load calculation developed, and concurrently the efficiency and dependability of refrigeration machinery was greatly advanced. Numerous shafts in Germany, Belgium, France, and England today testify to the reliability and economical surety of the freezing method. Applied to the South Shaft, which is circular in cross-section and 15-ft diam, the freezing method consisted of drilling holes 350-ft deep, through the water bearing strata into impervious ground-the freeze hole pattern being concentric with the shaft and 31-ft diam. The holes were cased with pipe closed on the bottom end. Smaller tubes were placed inside these casings and connected to a header supplying chilled brine from a refrigeration plant. The brine descended in the tubing to the bottom of the hole and ascended through the annular space between the two pipes to the top of the casing; flowed into the return header and back to the refrigeration plant. Under these conditions, each of the freeze hole casings became surrounded by a cylinder of ice

Jan 1, 1952

By R. R. Harvey

Recent evidence has indicated that the films forming at crude oil-water interfaces are the result of naturally occurring su,rface-active components in the crude oil rather than oxidation products resulting from exposure of the oil to air. Since the presence of such films may strongly affect the displacement of oil from porous media, a knowledge of their composition and formatiorz is of fundamental importance. In this study, without the assumption of a specific mechanism, film formation is considered to involve the transfer of a weakly surface-active species in solution in the oil to the oil-water interface. The film gas law and the Gibbs adsorption equation may thus he applied to the system. The rigid films which form upon decrease of the oil-water interfacial area are considered a result of the very slow rate of re-solution of the film material into the oil. When the shrinkage of the interface is very rapid, the amount of film material leaving the interface is negligible, and the system may then be treated in the same manner as an insoluble film. The combination of these treatments leads to a new concept of the film factor in which it may he quantitatively related to the concentration of film-forming material at the interface. Suitable experiments can then yield the following information. 1. Original concentration of surface-active species in the oil. 2. The change of concentration with time. 3. Concentration of surface active species at the interface. 4. The change of this concentration with time. 5. Interfacial tension of the system at any time and its variation with time. 6. Equilibriunz concentrations for a given set of conditions. 7. Concentration requirements for solid film formation. 8. Molecular diameter of the adrorbed species. These calculations may be made solely from data taken from measurements on the original oil. While using the pendant drop method of interfacial tension measurement of crude oil-water systems, Bartell and Niederhauser' remarked on the thin, transparent, pliable, solid films or membranes which were often formed at the interface between crude oil and water. As a result of their observations of these films, Bar-tell and Niederhauser concluded: 1. The films are formed by material from the oil adsorbed at the interface rather than by a reaction at the interface. 2. The adsorption of the film-forming material is a rather slow process. 3. There are good indications that the process is reversible; i.e., the film constituents may re-dissolve into the oil. 4. The film will spontaneously spread over any new surface formed. 5. The process of adsorption at the interface is accompanied by a decrease in the interfacial tension of the system. Although they had proved that film formation was not due to a reaction at the interface, Bartell and Niederhauser were unable to demonstrate conclusively whether these film-forming constituents were present in the original reservoir oil or whether they were formed as oxidation products after exposure of the oil to air. Recent evidence seems to point to their presence in the original oil. Although the true nature of the film-forming constituents is still uncertain, these conditions would be fulfilled by the assumption of the presence of a slightly soluble surface-active component in the original oil. This component would migrate to a freshly formed interface because it would thereby lower the free energy of the system. The component at the surface constitutes an expanded monolayer which would become compressed, upon retraction of drop, due to the slow rate of re-solution of the film components into the bulk of the oil. It is possible, by involved extraction processes, to separate or at least concentrate this film-forming fraction. However, using the assumptions made above, the technique of monolayer film study may be applied to reveal much of the nature of the adsorbing material without resorting to an actual separation of the film-forming constituents.

By Arthur Notman

IN VIEW of the wide publicity given to the charges by the Couzens Committee of the United States Senate of discrimination by the Bureau of Internal Revenue in favor of the copper companies, it becomes a matter of interest to consider the basis for these charges. The point to be determined is whether they rest on a foundation of fact or are purely and simply matters of opinion. The whole question boils down to the purpose of the Tax Law as applied to mines, which is to afford the same protection to them as provided for all other taxpayers, namely: that they were to be allowed to pay back as depletion to their owners the values of their properties as they existed or were estimated to exist on May 1, 1913, free from tax. To determine these valuations it was? necessary to select from a wide range of possibilities a set of values for a number of essential factors.

Jan 1, 1925

New York Meets first Wednesday after first Tuesday of each month. DAVID H. BROWNE, Chairman. PERCY E. BARBOUR, Vice-Chairman. A. D. BEERS, Secretary, 55 Wall St., New York, N. Y. C. A. BOHN, Treasurer. Boston Meets first Monday of each winter month. W. E. C. EUSTIS, Chairman. - R. L. AGASSIZ, Vice-Chairman E. E. BUGBEE, Secretary-Treasurer, Mass. Inst. of Technology, Boston, Mass. ALBERT SAUVEUR, H. L. SMYTH. Columbia Holds four sessions during year. Annual meeting in September or October. STANLY A. EASTON, Chairman. FREDERIC KEFFER, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. D. C. LIVINGSTON. FRANK A. ROSS.

Jan 12, 1916

Discussion of the paper of MANUEL EISSLER, presented at the New York meeting, February, 1915, and printed in Bulletin. No. 9.5, November, 1914, pp. 3661 to 2703. J. W. RICHARDS, So. Bethlehem, Pa.-I do not see in the paper a description of the Mabuki hearth as used for ore smelting. I noticed it described for concentrating matte, but I believe the older Japanese process was to use it for-smelting directly, by a pyritic smelting and Bessemerizing all in one operation, in the same simple hearth apparatus. There is a monograph published in German, on Copper-Ore Smelting in the Mabuki Hearth. At Ashio the practice of injecting bituminous coal at the, tuyères is noteworthy. It is very interesting to see two men load little cartridges on the end. of an iron rod with bituminous coal, and push them into the furnace tuyères, and with a piston inject 2 or 3 lb.. of bituminous

Jan 5, 1915

By John J. Howard

WE are approaching the depletion of our principal source of iron ore-the Great Lakes deposits, which have provided 85% of the nation's requirements for the past fifty years. This situation presents a threat to our standard of living and our position as a world power. Fortunately, in the Great Lakes region there are still tremendous quantities of potential iron ore in the form of the low iron, high silica rock called taconite. The economical extraction of iron from taconite will insure our future steel supply if no new deposits available to the United States even in time of war are discovered. In the new process presented here, the iron is reduced directly by a simple method and then separated from the silica. The product is "feed," not to the blast furnace, but to the steel plant. This process requires very much less plant, less physical and chemical treatment, and less fuel and auxiliary materials than the conventional ore concentration-blast furnace method. In my opinion, this new, fundamentally different approach offers a better hope for the solution of the iron ore problem.

Jan 5, 1950

By A. F. Meger

REPRESENTED here are the ideas and varied experiences of many people in the Hanna Coal Co. who have helped develop, over a number of years, an efficient and flexible method for spraying con- trolled amounts of oil on coal. Since the George- town preparation plant began operations early in 1951, oil treatment of coal has received special attention. It is believed that oil treating will satisfy present customers and also attract new markets. The first step in developing the new method of oil spraying was the construction of a dust cabinet for testing 50-lb samples of treated coal with the available oil sprays on the market. Tests results were tabulated for both indoor and outdoor storage.

Jan 7, 1954

No. 484.-A mining engineer and geologist of long and varied experience in North and South America is open for an engagement. Exploration and development work preferred. Rare minerals a specialty. No. 485.-Member, mining engineer, technical graduate, married, age 28, exempt, with 9 years experience at gold and silver, copper, lead, and coal mines, 4 years with present employers, is open for engagement as mine superintendent or foreman, or in charge of cyanide plant. Boston or New York interview after Oct. 10. Present position, day foreman at producing gold-silver mine in Montana. References. No. 486.-Member, age 34, married, varied experience in iron, copper, nickel, talc, etc., principally as surveyor, mine and surface geologist, and superintendent of explorations, is open for engagement. Preference, connection with some eastern consulting engineer or firm of engineers. No. 487.-Member, mine superintendent, 18 years' experience in the West and in the Lake Superior districts. Thorough business and technical training. Personal interview, preferably Chicago.

Jan 10, 1918