Search Documents

By AIME AIME

BERYLLIUM is one of the most interesting of the minor metals and distinctly a modern development, for until the last two decades it had practically no commercial importance whatever. Then it was discovered that when small quantities of it were alloyed with copper, a copper alloy of unusual and valuable qualities resulted. This is by far its major use-in the manufacture of strong, heat-treated copper-base alloys in which the beryllium content varies from about 0.3 to 2.5 per cent. Its second most important use, though much smaller, is in the form of oxide or other nonmetallic products in the fluorescent lamp, X-ray, cathode ray, and television industries. Certain beryllium salts have the quality, in common with several other materials, of transforming short-wave radiation and cathode rays to visible radiation. Such materials are commonly known as phosphors, and the beryllium salts are the most important phosphors now in use. The third largest use for beryllium is for ceramics, including refractories. Beryllium is also used in small quantities in the form of the metal itself.

Jan 1, 1943

By William S. Springer

A NEW preparation plant has been put in - operation to treat coal from the recently opened Concord mine, located about 15 miles west of Birmingham, Ala., by the Tennessee Coal, Iron & Railroad Co., a U. S. Steel subsidiary. The mine produces metallurgical grade coking coal from the American seam for use as coke in the company's blast furnaces at the Fairfield and Enseley works. The capacity of the operation is 1000 tons of run-of-mine per hr, approximately half of which is delivered to the by-product coke plant at Fairfield after beneficiation to metallurgical grade. The remaining portion of the mine run is rock and refuse removed during preparation. No boiler coal or other fuels are produced by this mine. Preparation of the coal is done both under- ground and on the surface. The underground primary crushing station removes some tramp iron, and screens and crushes the oversize, most of which is rock, to protect the main slope conveyor. The surface plant consists of a crushing and screening plant, large blending bins, a two- process washing plant, a water clarification and

Jan 1, 1950

By J. M. Smith, D. Kunii

Effective thermal conductivities of sandstones filled with stagnant fluids were measured using a steady-state technique. Data were obtained for seven sandstone samples, taken from four different locations and ranging in permeability from 18 to 590 md. The measurements with gases (helium, nitrogen, air and carbon dioxide) covered a pressure range from 0.039 psia to 400 psig. Data were taken for four liquids — n-heptane, methyl alcohol, 79.8 weight per cent glycerol-water solution and pure water at atmospheric pressure. The experimental results were used to evaluate the theoretical equations for predicting stagnant conductivities developed earlier 4 The low-pressure measurements permitted evaluation of the consolidation parameter bpDp/ks (necessary to utilize the theory) for the various types of sandstones. Using these characteristic values, the tbeoretical equations correlated well with the experimental conductivity data for the several fluids and rock samples. INTRODUCTION An aspect of heat transfer in solid-fluid systems of considerable current interest is the effective thermal conductivity of porous media. The stimulus for study of the subject arises from the need for sound procedures for designing thermal methods of petroleum production. The general system occurs when there exists a flow of fluid through the pores of the solid material. However, a logical starting point in developing a theory for predicting the effective thermal conductivity in the general system is to attack the special case when the porous solid is filled with stagnant fluid. Since the flow rates anticipated in thermal production processes are very low, such stagnant conductivities k,O are also of practical significance. Kunii and Smith4 recently reviewed the existing data for stagnant conductivities and proposed a theory for heat transfer in porous rocks. This leads to equations for predicting the stagnant conductivity as a function of the properties of the fluid and solid phases. The existing experimental information1-3,5,7,8 covered a range of porosities and agreed well with the theory. However, the available data were insufficient to examine critically the effects of two important properties on koe, — the thermal conductivity of the fluid and the pressure. The objectives of the present study are twofold: (1) to measure the effect on koe of (a) the pressure for gases, and (L) the thermal conductivity of the fluid kg for bloth gases and liquids; and (2) to determine for rocks of different porosities and permeabilities the apparent solid conductivity ks and the consolidation parameter bpDp/ks required in applying the theoletical equations. Measurements extrapolated to zero pressure are helpful in evaluating ks and the consolidation parameter. However, the extrapolations must be based upon data obtained at low pressures because in small pores the molecular conductivity of the fluid may be unusually depressed. This occurs when the mean free path of the molecules is of the same order of magnitude as the pore diameter, that is, in small-diameter pores at low pressures. The phenomenon has been studied recently by Schotte6in beds of unconsolidated fine particles. With particles in the size range of 45 to 200 microns, a significant reduction of kg with pressure was found even at absolute pressures greater than 1 atm. In the sandstones employed in the present investigation, pore diameters lower than those experienced by Schotte are likely, so that the effect would presumably be greater. SCOPE OF MEASUREMENTS Stagnant conductivities were measured for four types of sandstones using a total of seven samples. The characteristics of the samples, including porosity and permeability values, are given in Table

By C. W. Handy

ONE LAW cannot he evaded, the economic law of supply and demand. Silver, like any other commodity, is subject to this law; and its price in the long run is determined by existing conditions. I say "in the lone run because at times silver has appeared to mope contra to basic coalitions. Such movements, however, are, occasioned by the market's attempt to anticipate changes in these governing conditions. If the expected changes materialize then the new market level is justified, but if they do not then the market will revert to its previous status, A striking example of such a move occurred in November when the price advanced over 70, in ten days and then in the next two weeks lost more than it had gained. The reasons for this advance were that the speculative element interpreted certain events as favorable to silver namely, England suspension of the gold standard, higher shat prices, and the Chinese-Japanese crisis. When these expectations proved unjustified the inevitably, elapse followed became the governing conditions had not channel.

Jan 1, 1932

EVERY dry thing that burns easily and multiplies or maintains fire by its own intrinsic nature can be put into an incendiary composition and various effects are produced. Some of these things are mineral combinations, like sulphur or its oil; some others, [163v] hot, dry, and subtle substances, like saltpeter; and some are. unctuous things, like fats and oils of any kind; while some serve because of dryness, like pith and wood. Some of these things are natural and some artificial But now I set aside the search for these differences in their composition. This is what I have found among all the ancient and modern things that I have been able to seek, and first, back in the time of Alexander the Great. Marcus Graecus, who was perhaps the inventor or a great experimenter and practicer of such things, writes of many of them. I have chosen some among these, and one* is this: In order to make it, he took Grecian pitch, alchitran, live sulphur, tartar, sarcocolla, niter, and petroleum oil, one part of each, and, in addition, a double amount of quicklime. He mixed it all with oil of egg yolks. Having put it in a well-covered and closed vessel of glass or glazed earthenware under warm manure, he left it for a month. Then, having liquefied it over a slow fire, always keeping the vessel well closed, he finally put this liquor in hollow sticks, in little pots, or in vessels expressly made, all with a little fuse fitted in the middle. If I should have to do this, I would say that a little gunpowder should be put in, which should give beginning to the fire so that it would ignite more easily. I have also found that another fire is made. For this sulphur is taken, or oil of sulphur if it is possible to obtain, petroleum oil or some rock oil, juniper oil, very well-refined saltpeter, and for one part of each of these five parts of asphalt; in addition, take goose or duck fat, pure black pitch, varnish, pulverized dove's dung, and enough aqua vitae to cover all the aforesaid things.. Then it is put in a glass vessel under warm manure for

Jan 1, 1942

By L. Adler

Analysis of a mine roof can be based on fixed-end beam behavior. The author here analyzes the effects of zero restraint at deflecting beam supports. Formulae are given for determining permissible support deflections. Analysis of a mine roof in a bedded deposit usually follows the assumption that the behavior of the roof is analogous to a beam with both ends fixed. Yet it is recognized that the end restraint itself varies with the thickness of cover, so that at shallow depth the restraint is minimum, and at great depth, maximum.' Consequently, an analysis on the basis of fixed ends or full restraint represents only one extreme in the possible range of conditions. Since the actual amount of restraint is difficult to ascertain, a more rational approach is to consider the two extreme cases of end restraint. Such situations regarding uncertainty of the restraining effects of supports are not uncommon in structural analysis, and are handled in a like manner.' Since previous studies9)4 have dealt with full restraint, this paper will analyze the effects of zero restraint at deflecting beam supports. In such a case a mine roof with several intermediate supports becomes analogous to a uniformly loaded continuous beam on simple supports, as shown in Fig. 1A. Such a structure is statically indeterminate to a degree equal to the number of intermediate supports, n. Therefore, with the three equilibrium equations, n additional equations are needed. A number of methods exist to analyze this problem, but The Theorem of Three Moments is Simplest. The continuous beam is divided at each support into a sequence of simply supported single span beams, with the unknown end moments, as appears in Fig. 1B. Continuity requires that the common ends of adjacent beams have the same slope (Fig. 1C). eiB= B(i+l)~= ei(i+l)and MiB= Mti+I)A= Mi(i+i). [1I A Glossary of all terms is given in Table I. Furthermore, if we first consider that the supports do not deflect, the slope at a support is the sum of the slopes due to each of the individual loads shown in Fig. 2, yielding:

Jan 1, 1961

By Robert E. Wilson

TO show the vital importance of our future oil supplies to our economy, I will merely point out that this country, with something like 15 per cent of the world's land area and something like 7 per cent of the world's population normally uses between 65 and 70 per cent of the motor vehicles of the world, between 65 and 70 per cent of the world's rubber, and produces and refines between 65 and 70 per cent of the world's petroleum. Despite all the arguments as to which is cause and which is effect, all will agree that all three of these important industries are mutually dependent. If we had not been able to produce 65 or 70 per cent of the world's oil in this country we would not have the degree of mechanization, or the efficiency of transportation, or the high industrialization that we enjoy. Furthermore, the fact that oil has been plentiful and cheap has had a tremendous effect on all the things in which we as engineers are interested. For that reason, if for no other, it is well to look ahead to see what the outlook is for the near and far-distant future.

Jan 1, 1945

By G. W. LAAiIBOURNE

FEW mines possess a history of more fascinating interest than the Ontario at Park City, Utah. The famous Bonanza's production record of over $50,000,000; the great extent of its workings; the remarkable character of its mineralization; the fact that recent discoveries have shattered preconceived theories of the geology of the camp practically assuring the half-century old property a future as active and as prosperous as the past make the Ontario one of the unique mines of the world. A mere accounting of the wealth created by this historic property not only exemplifies the great profits

Jan 1, 1925

By Wilbert G. McBride

Two Also 3 1/2-ton motor trucks were used by Young Bros. while operating at the Mammoth Collins mine at Shultz, Ariz. One was equipped with an oil tank holding 1,075 gal. and was used for the transportation of "tops." The other was fitted with a stake body and used to carry machinery, wood, rails, pipe and all classes of miscellaneous supplies. The bodies were made of oak with maple flooring and were attached to the frame of the chassis by U-bolts, to avoid drilling the main members of the frame. Most of the hauling was done from Tucson, a distance of 47 1/2 miles. During the first 3 months, part of the road was in very bad condition and the tire cost was excessive. After this part was repaired the road was in fair condition, but never good. There were no excessive grades or bad sand, but wagon ruts, too narrow for the truck wheels and of a different gage, caused heavy tire loss; while chuck holes, sharp curves and stones, both imbedded and loose, were objectionable features. During wet weather the trucks could not get sufficient traction to climb some of the hills and were likely to stick in the mud in certain places, so that no attempt was made to run them unless they were on the' road when the rain started. This lost time amounted to about 5 per cent. of the total, but, whenever possible, it was utilized in making minor repairs. The price of gasoline was from 17 to 21 c. per gal. Rubber tires were used throughout. Drivers were said $4.50 to $5 per shift, and a return trip to Tucson was counted as two shifts even when made in one day. Drivers were provided with a room in Tucson and were paid for a11 time lost due to causes beyond their control. Trucks were loaded one way only. Speedometers were placed on both trucks but the excessive vibration soon caused them to fail. For this reason, and because no account was taken of the distance covered in picking up a miscellaneous load or in other minor ways, the mileage given is under the actual distance traveled. Some of the weights had to be estimated, but care was taken to have the number of ton-miles low rather than high, to avoid underestimating the costs. The cost of hauling from Tucson to the mines was $12 per ton

Jan 1, 1917

The Atlanta Mine is located in east central Nevada, in Lincoln County, 116 km (72 miles) south of Ely and 80 km (50 miles) northeast of the old mining town of Pioche. From this famous district, high-grade copper ore was mined and shipped to a smelter in Wales in the 1850s; an early day lead blast furnace was also in operation. The Standard Slag Company began operations in May 1975 on the well known Atlanta Mine, which was operated by Roy Hardy in the 1930s. The mill is currently processing 450 mtpd (500 stpd) of gold-silver bearing ore. Mining by open pit is in a brecciated zone occurring between limestone-dolomites on the foot wall and tertiary rhyolites on the hanging wall. The quartz breccia is considered among the most abrasive in the world - shovel teeth must be replaced every week. Stripping ratio is 3.9 to 1.0. Because of the hard abrasive ore, the crushing plant consists of four units: two jaw crushers in series, one Hydrocone, and one Gyradisc. Mine feed to the primary crusher is limited to 610 mm (24 in.) in size. The remaining crushers work in closed circuit with screens to produce a mill feed of 6 to 13 mm (0.25 and 0.50 in.). Hardness of the ore is demonstrated by the fact that the reversible liners of the primary jaw crusher had to be replaced in early 1978 after handling only 39,000 mt (44,000 st) at a cost of $0.095 per mt ($0.086 per st). Another example of the extreme abrasiveness of the breccia ore was the total cost per ton in 1977 for all wear parts in the comminution circuit, including screens and grinding media. This amounted to $2.84 per mt ($2.58 per st). The Atlanta grinding plant consists of three ball mills to grind the 7 mm (1 /4 in.) crushing plant product to 85 to 90% minus 150 microns (100 mesh). Feed rate to the primary Tricone mill is determined by maintaining a cyclone overflow at 28 to 38% solids, which controls the grind mentioned above. A mixture of 90 and 65 mm (3.5 and 2.5 in. ) balls are charged to this primary mill. Both the secondary mills are charged with 50 mm (2 in ) balls. Total ball consumption is 2 kg per mt (4 lb per st). All three ball mills use rubber liners. Primary mill cyclone underflows are fed to the secondary mills close circuited with the same cyclones.

Jan 1, 1981

By AIME AIME

In the uniform of his country for the second time, Harry Phillip Stolz. Chairman of the A.I.M.E. Petroleum Division, holds a commission as Lieutenant-Commander in the Naval Reserve and is attached to the office of Inspector of Naval Petroleum Reserves in California. During World War I he left his studies at Stanford University to join the Army and was granted a commission as Second Lieutenant of Infantry. He remained in the Army Reserve until 1938 when he resigned to accept a commission as a member of the Naval Petroleum Reserves Advisory Board. Born in San Francisco Jan. 29,1899, where his father had lived since 1880, he was in that city during the turbulent year of 1906 where the city was ravaged by fire and earthquake.

Jan 1, 1942

By David Cole

THE New Cornelia Copper Co. is mining and treating a 'monzonite " porphyry" copper deposit that is all hard rock. The oxidized surface shell, which constitutes the leachable part of the orebody, is measurably more resistent to crushing and comminution processes than is the underlying sulfide portion. The siliceous ribs running through the whole orebody are harder to crush than the main mass and there is no soft crumbly material to furnish the large volume of primary fines that features the crusher feeds of most other porphyry properties. New Cornelia ore reaches the primary crushers with a greater. proportion of large 'pieces. When the New Cornelia company first equipped its 'property, it used the following machines and flow , scheme to reduce the ore to leaching size:

Jan 1, 1925

By J. R. Dawson, A. B. Kinzel

THE purpose of testing is to determine whether the material in question is identical in all essential respects with similar material which has given satisfactory service. The most common method of securing such information is to select samples as representative of the entire material and subject them to destructive tests. As the welding industry grew, service data were accumulated and tests of welds took on new significance. New tests were devised and old tests modified so as to be more pertinent to welding. Moreover, in some cases the generally accepted procedure of testing by sampling is not accorded the same degree of confidence when applied to welds as in the usual applications. Thus, in instances where great hazard would be involved should the material fail, means of non-destructive testing have been sought with favorable results. Accordingly, tests used today may be divided into two groups, destructive and non-destructive tests.

Jan 1, 1930

By A. U. Seybolt, R. A. Oriani

The pressure and composition of the solid solution of nitrogen in chromium has been investigated as a function of temperature. The partial molal heat of solution, the activity of nitrogen in solid solution, and the partial molal free energy have been computed. The enthalpy of three reactions is summarized: N + 2Cr(3) = Cr2N(4), H° = —28,500 cal per mol 1/2N2(p) + 2Cr(8) = Cr2N(3)1 ?HO = —23,500 cal per mol 1/2N2(p) = N, ?H° = 5,000 cal per mol. WORKERS who have investigated the problem of the preparation of ductile chromium have been concerned with the effects of minor amounts of impurities upon this refractory metal. In particular, gaseous impurities such as oxygen and nitrogen have been suspected of causing trouble because of many known cases where brittleness in transition elements has been definitely traced to these elements. In order to evaluate the possible effects of the nitrogen impurity in chromium, it appeared desirable to learn something of the dependence of the nitrogen solubility upon temperature and pressure. Previous Work Maier3 in 1942 in his treatise on sponge chromium reviewed the thermodynamics of the chromium nitrides Cr2N and CrN, both of which are well-estab- lished compounds, but which apparently have not been studied in much detail. Maier presented some free energy-temperature expressions for the reactions 2 Cr,N = 4 Cr + N2 [1] and 4 CrN = 2Cr2N + N2 PI based mainly on the work of Satoh2 and Sano." Pearson and Ende3 in 1953 briefly reviewed the thermodynamics of Cr-N using the same data available to Maier, and also derived a free energy-temperature expression for reaction 1. Of the two nitrides mentioned previously, the present investigation was only concerned with Cr,N, since this nitride is in equilibrium with the metal phase, at least over most of the temperature range, Blix4 in 1929 established the structure of Cr2N (close-packed-hexagonal) by X-ray diffraction methods, and indicated that its homogeneity limits extend from 11.2 pet to 15.1 wt pet N. At a temperature of 1200°C, 38 mm Hg from the Maier expression and 43 mm Hg from the Pearson

Jan 1, 1957

By J. S. Kasper, R. M. Waterstrat

IN view of the recent findings of a pronounced ordering of atoms in s phase alloys containing elements of the first long row of the periodic table (and including molybdenum),l it is of interest to resolve the question of ordering for s phases containing second and third-row elements. Examples of the latter have been provided recently by Greenfield and Beck2 and two of them, Re-Cr and Ru-Cr, would appear to be favorable for a study of ordering by X-ray diffraction methods because of the considerable differences in the scattering factors concerned. In addition, s phase is found to occur in the Os-Cr system, where the difference in scattering factors is even larger. Accordingly, X-ray powder intensities have been measured in an attempt to learn the nature of the ordering, if any, in these three v alloys. Since there is no reported work on intermediate phases in the Os-Cr system, an exploratory investigation was made in this system, and it was found that, in addition to the s phase, the phase with the A-15 or ß-W structure also occurs. Specimen Preparation—The alloys were prepared by compressing mixed powders of —200 mesh size and sintering in an atmosphere of pure dry hydrogen. All alloys were rapidly cooled from the annealing temperature to room temperature in a stream of cold dry hydrogen in a water-cooled chamber. Table I lists the sources and purities of the starting materials, as well as the details of processing for each of the alloys investigated. Intermediate Phases in the Os-Cr System—In the absence of information on intermediate phases in the Os-Cr system, it was suspected that this system would resemble that of Ru-Cr, where a s phase, RuCr2,2 and a phase with the A-15 structure, RuCr3,3,4 have been identified. Both these phases were found in the Os-Cr system and at compositions

Jan 1, 1958

Discussion of the paper of Robert R. Abbott, presented at the New York Meeting, October, 1913, and printed in Bulletin No. 82, October, 1913, pp. 2389 to 2400. ALBERT SAUVEUR, Cambridge, Mass.:-Mr. Abbott has certainly made a strenuous effort to ascertain the influence of the various elements on the absorption of carbon by steel-a subject of great importance to those dealing with the case hardening of that metal. Because of the extensive and careful character of Mr. Abbott's experiments, one is all the more disappointed that his results, as he himself recognizes, are not more satisfactory; for, indeed they leave us just about where we were,-still entertaining uncertain views in regard to the carbon-absorbing power of various alloy steels. It might be asked whether Mr. Abbott's method of estimating the amount of carbon absorbed-namely, by weighing the specimens before and after the carburizing treatment-was the best one to select. Are not serious sources of error. inherent to such procedure because of the difficulty of satisfactorily removing the earburizing material attached to the specimen ? The method of least squares has certainly failed to solve the problem satisfactorily. By manipulating Mr. Abbott's results in a different manner I have obtained the following expression: P = 100 - 50 C - 7 Ni + 20 Cr, in which P represents the carbon-absorbing power; C, the percentage of carbon; Ni, that of nickel; and Cr, that of chromium. It is assumed that the carbon-absorbing power of pure iron, or what might be called its carburizability, is represented by 100. Applying the formula, for instance, to a steel containing 0.15 per cent. C, 3 per cent. nickel, and 0.50 per cent. chromium, its carbon-absorbing power would be 100-50X0.15-7X3+20X0.50=81.50; that is, 81.50 per cent. of the carbon-absorbing power of pure iron.

Jan 12, 1913

By J. E. Harris

The metallic elements, beryllium, calcium, cerium, lithium, manganese, titanium, vanadium and zirconium are used in metallurgical practice in relatively small percentages for the purpose of improving the physical properties of various alloys. No important uses for any of these elements have thus far been developed either in the pure form or in alloys of which they constitute the major constituent.

Jan 1, 1935

By Mark C. Malamphy

AT present the Federal Government represents the only organization applying geophysical methods of prospecting in Brazil. The geophysical work of the National Department of Mineral Production, which will be described in the following pages, must be considered as a program of experimental work designed to demonstrate the applicability of the more or less "standard" methods of geophysical prospecting to various problems of economic interest in Brazil by means of practical examples of results obtained in certain typical areas. Our work is somewhat similar to that of the Imperial Geophysical Experimental Survey of Australia, but our task has been greatly simplified by the ever increasing number of technical publications relative to the theory of instruments and methods.

Jan 1, 1936

By A. W. WALKER

All branches of production engineering showed steady and definite progress during 1941. Most of it has been of the slower and more conservative type rather than the sensational. To a large degree the changes have been influenced by the expanding war economy, and this tendency will probably be even more marked during the coming year. The stress of the times is placing more emphasis on the principles of engineering and conservation, with the object of obtaining the greatest possible recovery with a minimum waste or expenditure of equipment. Also available material supplies are often being turned to new uses.

Jan 1, 1942

By E. C. Truesdale

A FEW years ago H. M. Cyr, working in the Research Laboratories of The New Jersey Zinc Co., produced a few pounds of zinc1 of such purity that no other elements were detected in it by spectrographic analysis, using the facilities then available. This zinc contained less than one ten-thousandth of one per cent of metallic impurities.2 During the decade that followed upon the laboratory production of this "spectro-graphically pure" zinc, commercial developments brought about the production of large tonnages of zinc of purity exceeding 99.99 per cent, and today zinc of 99.999 per cent purity is produced and marketed as "chemically pure" zinc. Typical analyses of present supplies of high-purity zinc are given in Table 1. TABLE 1.-Typical Analyses Percentage by Weight Sum of Zinc Pb, Fe, Pb Fe Cd Al Cd Special High Grades 0.007b 0.005b 0.0056 none 0.0106 C.P. (chemically pure) <0.0002 0.0005° 0.000052 S.P. (spectrographically pure).. <0.0002d <0.00005d a A.S.T.M. Standard Specification for Special High Grade Slab Zinc (A.S.T.M. Designation: B 6-37). b Maximum. c Fe chemically determined. Pb and Cd are spectrographically determined. d Differences between composition of C.P. and S.P. zinc are discussed later in this paper. The availability of commercial tonnages of special high-grade zinc has been the basis for the development of the zinc-base die-casting alloy industry which, in the year 1936, consumed one-eighth of the zinc used in the United States for all purposes. This and the C.P. and S.P. grades have given impetus to scientific investigations into the properties of pure

Jan 1, 1939