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By C. H. Herty Jr, C. H.

FEW subjects have attracted the attention of metallurgists more than oxygen in steel. From the days of Mushet and Ledebui interest in this subject has been increasing, and as additional knowledge has become available, the problem has naturally grown more complex. Instead of using the simple term "oxygen" we now distinguish between iron oxide, silicates of various kinds, oxysulfides, oxygen as gas and oxygen in solid solution in steel. There are five general methods for determining oxides in steel: hydrogen reduction; vacuum fusion; various wet-extraction methods, including electrolytic methods; methods depending on volatilization of the iron away from the oxides; and metallographic methods. For oxygen in solid steel each of these methods has both advantages and disadvantages. The hydrogen-reduction method is of no use on steels above about 0.20 per cent. carbon; 1 furthermore, it gives only FeO and possibly some MnO. The vacuum-fusion method2 is expensive and gives total oxygen, with the exception of some A1203, and does not differentiate between the various oxides in which the oxygen exists. Most of the wet-extraction methods3 give only the more insoluble oxides SiO2 and A1203, though the iodine method gives MnO to an uncertain degree (information that may be more misleading then no information

Jan 1, 1957

By R. G. Green, R. L. Dowdell

LEAD POISONING as a result of eating lead pellets deposited in marsh areas is a cause of high mortality among ducks, geese, and other waterfowl ingested lead shot become trapped in the gizzard with gravel and are slowly ground away by the grit. Absorption of lead as it passes through the intestine in a finely divided state produces severe lead poisoning which is usually fatal. Ducks and geese with lead poisoning develop first a typical green diarrhea. Later, paralysis of the wing muscles prevents flight. As the poisoning continues with further grinding of the shot trapped in the gizzard, increasing paralysis reduces the bird to helpless-

Jan 1, 1937

By Norman D. Fitzgerald

IN 1943 the petroleum industry completed a series of practical adjustments to the acute problems which dominated the scene a year earlier. The crisis in petroleum transportation from the Gulf Coast to the East Coast was met by the completion of overland pipe lines supplementing emergency haulage by tank car so pressure on consumers along the Atlantic Seaboard was appreciably relieved. Later in the year when the western Atlantic was largely cleared of submarines, the sharp reduction in the hazards of marine transportation permitted the resumption of coastwise traffic and imports from South America. Nationwide restrictions in the use of gasoline and fuel oils became necessary as military demands for all petroleum products mounted to high levels.

Jan 1, 1944

By J. R. Dunn

Planning quarry operations and control of the quality of rock materials at Hudson Cement Co. at East Kingston, N. Y., are special problems because of multiple uses for the stone and the great structural complexity of the rocks. Problems have been largely solved by detailed geologic work. These geologic studies have paid dividends in long and short range planning, in assessment of reserves, in vastly reduced cost of chemical analyses, and in reduced drilling costs. Limestones of the Hudson Valley outcrop along the Hudson River from Albany to Kingston. Old established cement companies are located just south of Catskill and just east and southeast of Hudson, N. Y. The new Atlantic Cement plant is being constructed at Ravena. Hudson Cement located at East Kingston, is a newcomer and is closest to the New York metropolitan area (Plate I).

Jan 11, 1961

By R. E. Allen

ONE of the most unusual oil field engineering accomplishments of the past two years is the development and rapid advance in the directed drilling of wells. Directed drilling as referred to herein is the controlled steering of the drill stem in the required direction to a given location in the oil sand. The deliberate drifting of holes is an act so far removed from what has been considered good drilling practice that all of the old questions of correlation, drillability and production difficulties are revived. Only a few years ago, during the boom days of Seminole and Santa Fe Springs, the crooked-hole problem, as it was then called, occupied a primary position among the topics of the day in the fields of California and the Mid-Continent. The net result of all the discussion and study at that time was the conclusion that oil wells should be drilled with as little deviation from

Jan 1, 1933

NEW MEMBERS The following list comprises the names of those persons who became members during the period July 10 to Aug. 10, 1914: Members BAKER, FRED SHERMAN Tabowie, Unsan, Korea. BISSET, DANIEL GEORGE, Engr., 142 3d Ave., N. W., Edmonton So., Alberta, Canada.. BRANDT, MAURICE SHELDON, Chief Engr., White Eagle Mining & Milling Co., Box 298, Boulder, Colo. BROWNING, EDWARD, Min. Engr., Asst. to Supt., Cornwall Ore Bank Co., Cornwall, Pa. CASTLETON, WILLIAM ARTHUR, Mill Supt., East Butte Copper Mining Co., Butte, Mont. CHIDESTER, WALTER BARCLAY, Min. Engr., Care Mother Lode Mine, Greenwood, B. C., Canada. CLARK, EDWARD HARDY Mgr.,.Hearst Estate, 15 Broad St., New York, N. Y. CLARK, FREDERICK P., Chief Chem., International Lead Refining Co., East Chicago, Ind.

Jan 9, 1914

By R. A. Oriani

The partial molal volume of hydrogen is one of the parameters that describe the elastic interaction between the solute and the stress fields about inclusions, dislocations, and cracks. As such the partial molal volume is probably of importance in the elucidation of phenomena such as hydrogen embrittlement and hydrogen yield point. A knowledge of this quantity would also be helpful in thinking about the state of dissolved hydrogen in iron. However, because of the very low lattice solubility of hydrogen in iron the usual ways of determining the lattice expansion are not practicable. It is therefore of interest to apply the thermodynamics of stressed bodies to two sets of measurements of the effect of elastic stress upon the permeability of hydrogen in order to deduce a value of the partial molal volume, VH, of hydrogen dissolved in a iron. Beck ..' and previously de Kazinczy, observed that a uniaxial tensile stress increases the permeability of hydrogen in iron and in various steels. Beck et 01. employed Armco iron and A.I.S.I. 4340 steel, whereas de Kazinczy used a steel the composition of which was 0.13 C, 0.23 Si, 0.46 Mn, 0.006 P, and 0.038 S. Upon releasing the stress the permeability increment disappeared if the stress was below the elastic limit. Both investigators employed cathodic charging to introduce the hydrogen. de Kazinczy measured the permeation through a thin-walled tube by collecting the gas, whereas Beck et al. measured the permeation through sheets of various thicknesses by a very sensitive electrochemical technique. Both investigators measured the steady-state permeation at constant rate of hydrogen ion discharge, and Beck measured in addition the hydrogen diffusivity by a time-lag technique which is independent of the boundary conditions. Beck et al. and de Kazinczy found a linear relationship between log (J,/Jo) and the stress, where Ju/Jo is the ratio of the flux of hydrogen when the metal is under uniaxial tensile stress, a, to the flux under zero stress, for the same temperature and charging current. Beck et al. found in addition that the diffusivity of hydrogen is not changed by stress. Both investigators concluded that the observed change in permeability is due to an increase in hydrogen concentration, and furthermore that the increase in concentration is due directly to the thermodynamic effect of stress upon concentration. Accepting this assessment of the situation for reasons given below, one may use the equation3j4 in order to evaluate I/H, the partial molal volume of hydrogen. This equation is valid for the domain of a/E «¦ 1 (where E is the Young's modulus) and under the assumption that hydrogen expands the lattice isotrop-ically. From the data of Beck el al, one calculates V7H - 2.0 cu cm per g-atom, and from those of de Kazinczy one obtains 1.8 cu cm per g-atom. That the increase of concentration with stress is indeed of thermodynamic origin is attested to by the facts that the experimental results conform to the thermodynamic relation, Eq. [I], and that the results are the same whether a pure iron1 or each of two different steels172 is used. Neither of these facts wou1.d necessarily be expected if the effect of stress were, rather, to increase the ratio kn/k, of the kinetic factors of the following competing reactions: H(ads) — H (dissolved) Such a change of kinetics at the surface could be an alternative explanation of the effect of stress on the permeability. Although this writer does not deem this explanation to be the correct one for the reasons given above, it must be admitted that unambiguous proof that the phenomenon has a thermodynamic origin does not yet exist. Two kinds of experiments may be suggested. One is to plate a variety of metals on the input surface of the steel and repeat the stress experiment at a variety of hydrogen charging currents. The other is to employ somewhat thicker specimens in order to be able to apply uniaxial compressive stress. Eq. [I] shows that ln(c,/c,) depends on the sign of the stress, but it is difficult to see a physical basis for which k2/kl would depend on the sign of a. The present value of V^ in a iron agrees with phragmen's5 estimate, which he based on comparisons with the lattice expansion by hydrogen of titanium, zir-

Jan 1, 1967

By M. Shelef, A. W. Fletcher

The effect of alkali sulfates in promoting the sul-fation of nickel and copper in a bulk sulfide flota -tion concentrate by fluidized bed roasting has been studied in the laboratory, and it was shown that the various alkali sulfates promote sulfation to approximately the same extent. The sulfation of a mixture of synthetically prepared iron and nickel oxide and of nickel ferrite has also been studied. Nickel sulfation was promoted by high ratios of Fe:Ni and by the presence of sodium sulfate. THE work described in this paper was a continuation of earlier studies into the role of alkali sulfates in promoting the sulfation roasting of nickel sulfides1,2 in an endeavor to determine how the system was affected by the presence of compounds of iron and copper. The earlier work1 showed that, in the sulfation of NiO at 680°C, the reaction was limited by the formation of an impermeable film of nickel sulfate on the oxide surface. The relative effect of the various alkali sulfates in promoting nickel sulfation varied in the order: Li > Na >Cs > Rb > K A study of alkali sulfate/ nickel sulfate interactions at high temperatures showed that the promoting action was due to the fact that the nickel sulfate product layer sintered and agglomerated only when the more active additives were present. This resulted in the formation of discontinuities in the nickel sulfate layer so that diffusion of the sulfating gases to the NiO surface was no longer impeded and the reaction could proceed to completion. A similar explanation was used for the observation that sodium and lithium sulfates promote the oxidation of NiS to NiO at temperatures below 750°C since small amounts of nickel sulfate were formed during oxidation.2 It was of interest to study the effect of alkali sulfates on the sulfate roasting of a sulfide flotation concentrate which is typical of material treated commercially. In order to control temperature it is essential to roast sulfides in a fluidized bed and this technique was therefore used, although the batchwise operation of a small-scale laboratory reactor does not reproduce all conditions which prevail in full-scale continuous plant. The results obtained are therefore only comparative, and cannot be used for predicting the optimum conditions for metal extraction. The sulfation of synthetically prepared mixed oxides of nickel + copper and nickel + iron and of nickel ferrite was also studied to evaluate the relative effects of alkali sulfates with more complex systems. SULFATION ROASTING OF A SULFIDE FLOTATION CONCENTRATE The bulk sulfide flotation concentrate used in this work contained 7.92 pct Ni, 1.74 pct Cu, 35.66 pct Fe, and 31.28 pct S. The sulfide minerals present in order of abundance were pyrrhotite FeS, pyrite FeS2, pentlandite (FeNi)S, and chalcopyrite CuFeS2. Two samples described as coarse and fine were used. The coarse sample, which was a flotation concentrate (58 pct plus 300 mesh), was ground to 100 pct minus 350 mesh to produce the fine sample. Before roasting, the sample of sulfide concentrate was agglomerated by wetting witli a solution of the alkali sulfate (or water), thoroughly mixing, and drying at 110°C. This gave a cake which was gently crushed and screened, the -18 +100 mesh fraction being used for fluidized bed roasting. A similar-size fraction had been used by the authors in pilot plant work with a 4-in.-diam fluidized bed reactor.' In this work it was found that the molar ratio of additive to the total iron + nickel + copper content of the sulfide sample should be adjusted to a value of approximately 0.06, as this was the optimum amount necessary for nickel sulfation. Experimental. The fluidized bed reactor consisted of a quartz tube approximately 60 cm long and 30 mm in diameter resting in a vertical tube furnace. The sulfide bed (30 g) was supported on a bed of -4 +12 mesh quartz particles 3 cm high, which rested on a sintered quartz disc welded to the tube. The temperature of the furnace was controlled with a variable transformer to give a final bed temperature of 680°C. The bed was fluidized with air or mixtures of air + 10 pct v/v SO2, at a total apparent gas velocity of 60 to 65 cm per sec at 680°C. The SO2 was introduced into the fluidizing air stream only when the oxidation of the sulfides was completed. At the end of the roasting period the calcine was leached with boiling water and the

Jan 1, 1964

By Boris J. Kochanowsky, Burke O. Trafton

Because of the strict requirements on the quality of limestone that are dictated by the users, the operator was compelled to find new approaches to produce a product of uniform and acceptable quality. The raw material is controlled and monitored every two minutes by a special computer in order to ensure its quality. The required minimum and maximum quality constraint had an adverse effect on performance and consequently cost. In order to improve this performance, a Monte Carlo simulation model was developed and tested for the optimal truck allocation. The input data is based upon the distribution of equipment performances and costs.

Jan 1, 1969

By A. H. Tousley

Current problems in the cement industry are discussed and suggestions for solving them by modernization are made. Cement facility modernization is discussed in considerable detail with examples illustrating before and after conditions. Itemized are the improvements realized in better working conditions, better efficiency, higher production, lower costs, and better community relations. These improvements are related to the overall profitability of the particular plant or facility.

Jan 1, 1972

By J. S. Rinehart, W. C. Maurer

The mechanics of impact crater formation in rock, particularly sandstone, has been sutdied, the velocity range being approximately that normally associated with oilwell gun perforators. The bullets were small steel spheres having diameters of 3/16, 9/32 and 7/16 in; impact velocities ranged from 300 to 7,000 ft/sec. The craters have two distinct parts — a cylindrical hole (or burrow) with a diameter the same as that of the impacting sphere, and a wide-angle cup comprising most of the volume of the crater. The burrow is fornred as material in front of the projectile is crushed and pushed aside, forming a cylindrical hole surrounded by a high-density zone. The clip forms as fractures are initiated in front of the projectile and propagate along logarithmic spirals, approximaling maximum shear trajectories, to the free surface of the rock. A most significant observation (made for the first time) was that, below the base of the cup in one type of sandstone, there are a group of similar fractures, not extending to the surface, which are spaced uniformly a few millimeters apart. Each fracture follows roughly the contour of the base of the cup and appears to require a certain threshold impulse to initiate it. These fractures comprise a relatively high fraction of the total, newly exposed surface area. The volume of the material removed by crushing varies as the first power of the impact velocity and the volume removed by fracturing, as the second power of the impact velocity. Penetration varies linearly with the impact velocity and is inversely proportional to the specific acoustic resistance of the target material, the proportionality constant being dependent upon the shape of the projectile. INTRODUCTION Yield of oil from a producing well is frequently enhanced by firing bullets and shaped charges through the well casing into the oil-bearing rock, forming craters and fractures from which oil can flow more readily. The purpose of this investigation has been to develop a better understanding of the mechanics of impact crater formation in rock, particularly sandstone, the velocity range being approximately that normally associated with oilwell gun perforators. FORCES OPERATIVE DURING IMPACT When a projectile moving at considerable velocity strikes a- massive target such as oil-bearing sandstone, intense and complex transient stress situations develop within both the projectile and the rock or sandstone against which it is striking. Usually the struck rock fails, the missile or projectile penetrating into the rock to some depth where it comes to rest or is forcibly ejected from its burrow by expansion of a plug of target material compressed in front of it. When the impact velocity is very high, the projectile itself may fail, breaking apart or becoming distorted; this situation is not considered here, the discussion being limited to nondeforming projectiles. Many experimental studies'.' have been carried out to determine the nature of the mechanics of crater formation and the salient features of the forces coming into play, some of the earliest studies being the French Army experiments performed at Metz between 1835 and 1845.' The stratagem in most instances has been to make a post-mortem examination of the crater, measuring volume and depth of penetration and deducing force relationships from these observations rather than performing the more difficult (usually almost impossible) feat of measuring stresses during penetration. In many materials, the force acting during penetration of the projectile is found to be the sum of two components—(1) a constant force, independent of the velocity, representing some inherent strength of the target material; and (2) a component, proportional to the square of the velocity, representing inertial forces. For such materials, the average force per unit area acting on the projectile at any instant while it is in motion and being decelerated may be written F/A = a + bv2 . . . (1) where v is the velocity of the projectile at that instant, A is the cross-sectional area of the penetrating projectile taken normal to its trajectory, and a and b are constants which are dependent upon the target material and the shape of the projectile. It follows that the total penetration s is given by .........(2) where v, is the velocity of the projectile when it just strikes the target. Values of a and b for spherical projectiles impacting in a loose sand-gravel mixture and compacted earth were obtained in the Metz experiments. For sand-gravel, a and b are 620 psi and 0.0115 (psi) (ft/sec)', respectively; and for compacted earthworks, a and b are 432 psi and 0.0008 (psi) (ft/sec)'. Figs 1 and 2

By Theodore M. Barry

Work measurement is the most common of many titles given to determining the amount of human work required to do any job. A new technique-like most modern management tools-it still needs years of constructive research. Yet despite known imperfections, it is probably the most enthusiastically used tool of cost control developed in the last hundred years. Over 85 pct of all companies employing more than 100 workers in one of the major industrial areas use work measurement. For a good reason, however, this has not been true in the mining industry until very recently. The facts make an interesting story.

Nov 1, 1955

By H. K. Work, H. B. Emerick

IN the past year the steel industry underwent an abrupt conversion from a war tempo to a highly competitive peacetime schedule. It is still too early to gain a comprehensive picture as to which of the measures in production metallurgy, that made the war effort so successful, will remain in the postwar production of steel, but many of them undoubtedly will fill an important place after the war. Considerable speculation has developed regarding the disposition of the war-born production facilities of the steel industry. These include new open-hearth and electric furnaces, as well as vast numbers of auxiliary, supplementary, and balancing units that increased and speeded up production beyond the normal capacities of existing melting furnaces and finishing mills. Although these facilities were installed primarily to help meet war requirements, consideration was also given, in planning, to their possible peacetime use. The new equipment is generally modern and efficient, and it seems reasonable to suppose that strategically located units will gradually be absorbed by various steel companies to supplement their own facilities, or to replace in kind, obsolete and inefficient equipment now ready to be scrapped. Some, however,

Jan 1, 1946

By K. D. Jacob, W. L. Hill

THE bulk of natural phosphates is comprised of calcium phosphates, which are usually apatites;1 calcium aluminum phosphates such as pseudowavellite;2 and aluminum phosphates, which occur in extensive deposits, notably on Grand Connetable Island.3 Nearly all deposits of current commercial value are apatite, often with admixed material of other classes. In the trade coarsely crystalline material, mainly fluorapatite of igneous origin, moves as apatite, whereas the fine-grained material of sedimentary origin is marketed as phosphate rock. The latter classification includes the phosphate shales in western North America. Although several genetic varieties of phosphate rock are recognized,4 most known reserves are of marine origin. Calcium phosphate is concentrated from Florida land pebble and Florida hard rock deposits and from Tennessee brown rock deposits. Phosphate Rock as a Fluorine Carrier: More than two decades ago Reynolds and Jacob surveyed the fluorine content of commercial phosphate rock from various parts of the world.3,5 Later these samples were reanalyzed by a new and more reliable method of determining flourine.6,7 The revised results with interim additions of new samples, published a few years ago in a brief summary,' are shown in Figs. 1-3. Through the points representing the respective varieties of rock medial straight lines are drawn. In some instances the lines are well defined by the points; in others, where scattering renders the position of the best line uncertain, the greater weight is given points near the end of the covered range. Wherever distinct varieties are not recognized among regional deposits the custom is to identify the sample with the geographical location of the deposit.

Jan 10, 1954

By G. M. BUTLER

TWENTY-ONE of the states in the Union, the Territory of Hawaii, and seven provinces of Canada now have in operation laws requiring that professional engineers be registered or licensed. In addition, two states require that civil engineers be registered, and one other state demands registration of structural engineers. Moreover, nearly every year sees additions made to the list. The registration movement, fostered by the American Association of Engineers, now has the powerful, energetic backing of the An1,erican Society of Civil Engineers, which is itself now fostering registration legislation, and there is a strong sentiment in favor of registration in the American Institute of Electrical Engineers and the American Society of Mechanical Engineers. Only in the American Institute of Mining and Metallurgical Engineers is anti-registration sentiment, strongly dominant, but many members of this organization are enthusiastic advocates of registration.

Jan 1, 1930

By Hans Lundberg

IN last year's report on the progress of geophysics, the airborne magnetometer was the featured new development. At that time only a relatively small number of surveys had been made. During 1947, the airborne magnetometer was used in making many surveys and is again one of the high lights of the year in geophysics. This report is mainly concerned with geophysics as applied to the search for minerals exclusive of petroleum. In 194,5 and 1946, the use of the magnetic method reached a peak, partly because of an active period of prospecting brought on by an active mining market, particularly in Canada.

Jan 1, 1948

By George W. Riter

Discussion of the paper of H. 0. Hofman and C. R. Hayward, presented at the New Haven Meeting, February, 1909, and printed in Bulletin No. 30, June, 1909, pp. 513 to 529. GEORGE W. RITER, Salt Lake City, Utah (communication to the Secretary*).-In their paper, Messrs. Hofman and Hayward deal with a branch of silver metallurgy that is on very uncertain ground, both as a commercial process and as a metallurgical science; moreover, its field is limited to few localities and to peculiar conditions. The literature on the subject is incomplete and full of conflicts. The paper under discussion clears u p no disputed points; on the contrary, because of hasty generalization, its tendency is towards further confusion. In Table I., the authors assume that each test-lot of 1,800 g. of ore contained exactly 5.499 g. of silver, that any variation in the quantity of silver recovered, however slight, should be ascribed to variation in the time of grinding. It is barely possible that the ore was mixed so uniformly as to justify this assumption; but those of us who know how difficult it is to get uniform samples of any ore in which silver mineral is present in rich particles will have a doubt on this point. The unlikelihood of getting absolutely uniform test-lots of ore also reflects on the data in Table II., on the effect of varying the amount of salt in a pan-charge. The authors say " The salt series was the last one that was investigated." This again raises a question as to whether the ore was split into test-lots at the time of sampling, or whether it was kept in bulk in such a way as to permit mechanical concentration of values before the end of the experiments. The conclusion following Table II.: " There is no reason, therefore, for going beyond six per cent. of salt," is hardly to the point. If we assume that salt is of benefit only when in solution, it follows that the relation between the quantity of salt

Mar 1, 1910

By Cloyd M. Smith

A FEW years ago, the Ventilation Committee established the practice of presenting one topic each year for discussion at the annual meeting. The practice has met good response on the part of committee members and I suggest that it be continued. The topic chosen for this year, "Underground Anemometry," is a topic which has bothered me for more than 20 years. It seems to me that the coal industry is content to rely on slipshod methods for measuring the rate of flow of air underground, so I prefaced my discussional charge to committee members with the statement that I regard air measurements made in the usual way, with hand held anemometer, as no good. Agreements and disagreements came in from more than a dozen engineers, some of whom are with operating companies, coal and metal; some with manufacturers; others with government agencies.

Jan 1, 1949

By Joan Melcher

The oil embargo and increasing disillusionment with nu- clear power have put this country's abundant coal reserves in growing demand. Both the government and industry are looking toward increased coal mining, and with this goes an increased interest in new and advanced methods of coal utilization. One advanced coal system stands out among the rest-magnetohydrodynamics (MHD). Its high efficiency, strong probability of sulfur dioxide control, and limited consumption of cooling water place MHD in a unique position to help the power generation industry. Another point in MHD's favor is the capital costs of operation, which are lower than those of other advanced technologies. However, initial costs are higher and realization of a commercial MHD plant in this country may be more than a decade away.

Jan 12, 1977

By Joseph T. Roy

MINING revival during the last few years has brought about a considerable increase in the number of gold and silver determinations made, noticeable in all branches of the industry but especially so in the business of a custom smelter. At East Helena, solely a custom smelter the assay department found that the four assay furnaces available were inadequate to handle the increased amount of work. These furnaces were of a standard design, having duplex muffles, one superimposed on the other; each muffle was 12 1/2 in. wide, 18 1/4 in. long and 6 in. high, and could handle 72 cupels or 20 fusions. Since the heat varied considerably between the upper and lower muffles, cupellations were not ruin in both at the same time. To speed up assaying, E. A. Meale, chief chemist, had the happy idea of enlarging a muffle furnace, originally designed by the Montana Power Co., so that one muffle would acconmmodate at least as many determinations as the duplex muffles. An order was given to the Denver Fire Clay Co. for a Carbofrax muffle of the size required and the local engineering department enlarged the furnace to accommodate the muffle. Details of the

Jan 1, 1938