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The Hanna Coal & Iron Corp, pilot plant at Randville, Mich , is handling about 250 tons of low grade Michigan core daily Ore is obtained from an ,open pit near the plant Operating alone In the area, the project was first announced about a year ago Construction began June, 1951 and actual testing started about the first of the year A paper presented by Plant Superintendent Elton P Geist at the Upper Peninsula AIME spring technical session, described the plant and outlined the present flow sheet A two-step beneficiation scheme is presently being used It utilizes both flotation and gravity methods After crushing and grinding to 28 mesh, the ore is passed over Humphrey spirals, making a coarse iron concentrate Tailings from the spiral concentrate are then reground and floated to produce iron concentrate and a final tailing Geist stressed that the present flow sheet is tentative and one of several possible variations Testwork is continuing at the plant and future work will determine the method of agglomeration to be used

Jan 1, 1952

By Eugene Guccione

One of the world's most respected scientists, Dr. Hans A. Bethe (see box) has concluded that if anything can solve the energy crisis, it will be coal and uranium. "It is an illusion to think that we can solve our problem by energy conservation alone. For the next few years, conservation must play a very important role, but at the same time, we must see and develop all our alternative energy sources," he said. In his series of five lectures on the energy crisis, given at the University of Utah while he was visiting professor there during February 1974, Dr. Bethe examined all the existing and newly proposed energy sources. He very quickly ruled out solar power, wind power, and tidal power. Solar power, he said, would be 3% to 4 times more expensive than nuclear energy and would only make sense in tropical areas; wind power, which could at best produce one-tenth as much energy as solar, is "for the birds;" and tidal power, which can be exploited in only a very few coastal locations, is "for the fish."

Jan 5, 1975

By Dilip K. Das, Douglas T. Pitman

ONE of the major uses of barium in metallic form is as a getter material in vacuum tubes. Because of the high chemical reactivity of the metal, Ba-Al alloys are extensively used. Numerous methods for the preparation of Ba-Al alloys have been published, a few of which1-4 are cited here. Most of these methods were found to be quite elaborate, involving the reduction of BaO, and not too well adapted for the close control of the final composition of small amounts of alloys prepared for laboratory use. A simple laboratory method for the preparation of Ba-A1 alloys in small batches starting from pure metals was devised, so that it was possible to control the desired compositions to within 1 pct. The pertinent features of the alloy system Ba-Al5 are 1) an intermediate compound BaAl, with the melting point of 1050°C, and 2) a eutectic between aluminum and BaAl4 at 98 pct Al. The accompanying sketch shows the experimental arrangement for the preparation of the alloys. Weighed amounts of aluminum and barium were placed in an alumina and a stainless steel crucible, respectively. According to the supplier's specification, the purity of the metals used in the alloys is as follows: a) aluminum rods—99.9 pct Al, and b) barium rods—99.5 pct Ba. The stainless steel crucible, tapered at the bottom and having a 1/16 in. diam hole, rested on top of the alumina crucible. The assembly was placed inside a graphite sleeve which rested on a refractory platform. The platform moved the assembly up and down through the field of a radio frequency coil. A glass bell jar was placed between the crucible assembly and the radio frequency coil to maintain a steady flow of helium around the melt. A small window was cut out on the wall of the alumina crucible to observe the progress of the re- action and to record the temperature with an optical pyrometer. The platform was first raised high enough to move the barium out of the radio frequency coil field in order to allow only the aluminum to melt. The assembly was then lowered so that the barium began to melt and flow out through the small orifice into the molten aluminum. In order to keep the violence of the exothermic reaction under control, the rate of flow of barium was carefully regulated by raising or lowering the crucible assembly. All the samples prepared by this technique were examined by a Norelco X-ray diffractometer using CuKa radiation, The diffraction specimens were prepared by placing the finely powdered samples in flat specimen holders. The Ba-Al alloys prepared with a high barium content were found to consist mainly of BaAl4. The structure of BaAl4 has previously been reported by Alberti and Andress.8 They found that BaAl4 was body-centered-tetragonal with an a0 = b0 = 4.530Å and c0 = 11.14Å. An alloy whose composition was found by chemical analysis to be almost 100 pct BaA1, was used to determine the relative intensities. The d-spacings were obtained from the same alloy to which a small amount of tungsten had been added as a calibrating material. Accurate values for a, and c, were calculated according to the method proposed by Taylor and Floyd.' The calculated values are: a, = b, = 4.566Å and c0 = 11.250Å. The measured d-values for BaAl4 are shown in Table I along with relative peak intensities above background and hkl indices. Acknowledgment The authors are grateful to L. J. Cronin, the head of the Techniques Dept., for suggesting the problem and for his constant interest. References 1Froges and Camargue: German Patent No. 809107, 1951. French Patent No. 935324, 1949. 2E. Bonnier: Annales de physique, 1953, vol. 8, pp. 259-312. 3M. Orman and E. Zemhela: Prac Institute of Metals; 1952, vol. 4, pp. 437-445. 4E. Fujita and H. Yokomizo: Reports Gov. Chemical Industrial Research Institute, Tokyo, 1952, vol. 47, pp. 291-297. 5E. Alberti: Ztsch. fur Metallkunde, 1934, vol. 26, p. 6. 6E Alberti and K. R. Andress: Ztsch. fur Metallkunde, 1935, vol. 27, p. 126. 7 A. Tnslor and R. W. Floyd: Acta Crystallographica, 1950, vol. 3, p. 285.

Jan 1, 1958

By Bobby P. Faulkner

The Tennessee Copper Co.'s flotation plant, refer- T red to as London Mill, processes approximately 4800 tons of a massive complex sulfide ore per day. The ore is predominantly pyrrhotite and pyrite, the other sulfides being chalcopyrite, sphalerite, and a small amount of galena. Magnetite of economic value is also present. There are four concentrates produced. In decreasing tonnage, these are iron, copper, zinc and lead. The ore feeding the mill is a composite of ores from five mines which vary in grade. Therefore, in order to provide a fairly constant feed to the mill, the ore is blended several times before reaching the flotation machines. The flotation plant is divided into three main sections: bulk, copper and zinc. Fig. 1 shows a simplified flowsheet. The first two sections, the bulk and copper, were the two sections studied most closely in utilizing the computer.

Jan 11, 1966

By AIME AIME

M ODERN metallurgy properly belongs to this century. The great advance made in this science is directly attributable to the discovery of the Roentgen rays. Application of the results of this discovery, together with the more recent corroborating studies in electronic diffraction have definitely and for all time established this science. Metallurgists today speak with familiarity of the atoms of the different metals in terms of their orientation, atomic volumes, lattice structures, dimensional lattice constants distance of nearest approach, and the like. One matter of profound interest, which is quite staggering to the imagination of the human mind, is the enormity of the number of atoms even in a small particle of metal. As an illustration, let us compute the number of atoms in the volume of one cubic centimeter in a single grain of absolutely pure copper. Eighteen and a fraction cubic centimeters equal the volume of one cubic inch.

Jan 1, 1940

By C. M. Brinckerhoff

Safety work in mining at the Andes Copper Mining Company, Potrerillos, Chile, is divided into three parts: (1) accident prevention, (2) fire prevention and protection, and (3) silicosis prevention and control. In the company's operations a steady campaign has been waged to reduce accidents and silicosis, and to prevent fires. In the following pages the safety record for the past twelve years will be examined and the methods explained by which the accident rate was reduced. Table 1 contains yearly data pertaining to the scale of the mining operations and the accident record. Block caving is used for all ore production and the tonnage mined has aver- aged 30,000 short tons per day for the past seven years. Table 2 classifies 44 fatal accidents which have occurred since 1935. The leading causes of accidental death are transportation of ore and use of explosives, followed in order by per- sons falling, falls of ground, and by asphyxiation. In the case of serious accidents, however, the greatest cause is falls of ground, followed, in turn, by ore

Jan 1, 1949

By Earnshaw Cook, J. A. Fellows, Howard S. Avery

Heat-resistant alloys of the higher nickel and chromium ranges have been empirically developed through the practical experience of the past two decades to a position of significant industrial importance. Few quantitative metallurgical data have been published, however, that could be related directly to engineering specifications and design. Inadequate information led to the inauguration, in 1934, of a research directed toward a better understanding of the properties and performance of these steels at temperatures between 1400° and 2000°F. Investigation was concentrated upon the 26 per cent Cr:I2 per cent Ni type, which owes its extensive application to an excellent combination of economy, strength and surface stability at elevated temperatures. The requirements of the oil-refining industry have been prominent in influencing the scope and evolution of the program. Creep strength at the maximum allowable deformation ranges has been employed to evaluate the merits of these alloys. Permissible elongation rates vary from 1.0 per cent in one million hours for turbine blades to I .o per cent in ten thousand hours for tube supports and heating-furnace equipment. Throughout this paper, the limiting creep stress (L.C.S.) for a given temperature has been defined as the stress that will produce a uniform elongation rate (stage 11) of one per cent in ten thousand hours as extrapolated from rates per hour for tests of less than two thousand hours duration. Certain current specifications require a minimum L.C.S. of 1600 lb. per sq. in. at I800°F., of 3600 lb. per sq. in. at 1400°F., and include a tensile acceptance test at room temperature, after aging for 24 hr. at 1400°F., as a measure of embrittlement in service. An elongation of 4 per cent is considered satisfactory for general use, while a minimum of 9 per cent is prescribed on occasion. Many differences of opinion concerning the properties and performance of these alloys appear to result from their sensitivity to unappreciated variations of chemical analyses which, for example, may change their L.C.S. from 3500 to 350 lb. per sq. in. at 1800°F. Within broad chemical limits, it is possible to balance the six or more important elements present to attain desirable properties with a number of different combinations. One method for adjusting the composition has been described under the sponsorship of the Alloy Casting Institute,' in which, by maintaining a substantially austenitic* alloy, optimum creep strength and minimum tendency to embrittle after aging are expected. Unless, however, the limits are undesirably close, it has not been possible to ensure a moderate range of strength and of ductility by any chemical specification alone. There is a definite need

Jan 1, 1942

By J. A. Fellows, Earnshaw Cook, Howard S. Avery

Heat-resistant alloys of the higher nickel and chromium ranges have been empirically developed through the practical experience of the past two decades to a position of significant industrial importance. Few quantitative metallurgical data have been published, however, that could be related directly to engineering specifications and design. Inadequate information led to the inauguration, in 1934, of a research directed toward a better understanding of the properties and performance of these steels at temperatures between 1400° and 2000°F. Investigation was concentrated upon the 26 per cent Cr:I2 per cent Ni type, which owes its extensive application to an excellent combination of economy, strength and surface stability at elevated temperatures. The requirements of the oil-refining industry have been prominent in influencing the scope and evolution of the program. Creep strength at the maximum allowable deformation ranges has been employed to evaluate the merits of these alloys. Permissible elongation rates vary from 1.0 per cent in one million hours for turbine blades to I .o per cent in ten thousand hours for tube supports and heating-furnace equipment. Throughout this paper, the limiting creep stress (L.C.S.) for a given temperature has been defined as the stress that will produce a uniform elongation rate (stage 11) of one per cent in ten thousand hours as extrapolated from rates per hour for tests of less than two thousand hours duration. Certain current specifications require a minimum L.C.S. of 1600 lb. per sq. in. at I800°F., of 3600 lb. per sq. in. at 1400°F., and include a tensile acceptance test at room temperature, after aging for 24 hr. at 1400°F., as a measure of embrittlement in service. An elongation of 4 per cent is considered satisfactory for general use, while a minimum of 9 per cent is prescribed on occasion. Many differences of opinion concerning the properties and performance of these alloys appear to result from their sensitivity to unappreciated variations of chemical analyses which, for example, may change their L.C.S. from 3500 to 350 lb. per sq. in. at 1800°F. Within broad chemical limits, it is possible to balance the six or more important elements present to attain desirable properties with a number of different combinations. One method for adjusting the composition has been described under the sponsorship of the Alloy Casting Institute,' in which, by maintaining a substantially austenitic* alloy, optimum creep strength and minimum tendency to embrittle after aging are expected. Unless, however, the limits are undesirably close, it has not been possible to ensure a moderate range of strength and of ductility by any chemical specification alone. There is a definite need

Jan 1, 1942

By Michael S. Koleda

Less than two years ago, the, Congress, with broad bipartisan support, passed the Energy Security Act of 1980. A decade marked by ten- fold increases in world oil prices and two major interruptions in oil flows from the Middle East had ended. An all-out national commitment to transform America's vast tar sands, oil shale and coal resources into conventional fuels had begun. The national synfuels effort was to be public-private cooperation at a scale unmatched in peace time. Private industry would own and operate the synthetic fuels facilities. Government would reduce market uncertainties to acceptable levels. The potential government commitment was substantial. Up to $88 billion would be available through the Synthetic Fuels Corporation, principally in the form of contingent financing. Billions more would be spent through Department of Energy programs. Additional incentives for alternate energy development were contained in the Energy Tax Act of 1978. The Energy Security Act clearly specified national synthetic fuels production objectives: 500,000 barrels per day by 1987 -- 2 million barrels per day by 1992. Finally, said Congress, Uncle Sam was going to do something about rapidly rising oil prices, uncertainties of energy supply, and the resulting disruption to the U. S. economy. Simply put, the purpose of the Energy Security Act of 1980 was to provide government guarantees sufficient to get synthetic fuels projects off the private sector drawing boards and into commercial production. Because of their huge cost, technological uncertainty, and lengthy pay-out period, these projects were always second place to projects of smaller size, known technology and more rapid pay-out. The Energy Security Act was the legal expression of public policy to bring the free-market synfuels timetable into line with the faster paced political timetable in the interest of national energy security.

Jan 1, 1982

By William B. Plank

NEVER before have so many men chosen the mineral technology field for their college training. In the college year 1936-'37, 7190 such students were enrolled in the 53 schools of the United States. My last study of the mineral technology schools of the United States and Canada was made for the year -1934-'35, and the current study, as the previous one was made for the A.I.M.E. under the auspices of the Division of Mineral Industry Education. Altogether, four studies of enrollment have been made. The first three were for successive college years beginning with 1932-'33. This present one covers a two-year period, for the purpose of these studies may he served satisfactorily if they are made biannually. The data on the schools were collected in the same way as for former studies, 'namely, by questionnaire, dated in this case Nov. 18, 1936. The figures reported are therefore comparable with those of former cars.

Jan 1, 1937

By J. A. Fellows, Earnshaw Cook, Howard S. Avery

HEAT-RESISTANT alloys of the higher nickel and chromium ranges have been empirically developed through the practical experience of the past two decades to a position of significant industrial importance. Few quantitative metallurgical data have been published, however, that could be related directly to engineering specifications and design. Inadequate information led to the inauguration, in 1934, of a research directed toward a better understanding of the properties and performance of these steels at temperatures between 1400° and 2000°F. Investigation was concentrated upon the 26 per cent Cr:12 per cent Ni type, which owes its extensive application to an excellent combination of economy, strength and surface stability at elevated temperatures. The requirements of the oil-refining industry have been prominent in influencing the scope and evolution of the program. Creep strength at the maximum allowable deformation ranges has been employed to evaluate the merits of these alloys. Permissible elongation rates vary from 1.0 per cent in one million hours for turbine blades to 1.o per cent in ten thousand hours for tube supports and heating-furnace equipment. Throughout this paper, the limiting creep stress (L.C.S.) for a given temperature has been defined as the stress that will produce a uniform elongation rate (stage II) of one per cent in ten thousand hours as extrapolated from rates per hour or tests of less than two thousand hours duration. Certain current specifications require a minimum L.C.S. of 1600 lb. per sq. in. at 1800°F., of 3600 lb. per sq. in. at 1400°F., and include a tensile acceptance test at room temperature, after aging for 24 hr. at 1400°F., as a measure of embrittlement in service. An elongation of 4 per cent is considered satisfactory for general use, while a minimum of 9 per cent is prescribed on occasion. Many differences of opinion concerning the properties and performance of these alloys appear to result from their sensitivity to unappreciated variations of chemical analyses which, for example, may change their L.C.S. from 3500 to 350 lb. per sq. in. at 1800°F. Within broad chemical limits, it is possible to balance the six or more important elements present to attain desirable properties with a number of different combinations. One method for adjusting the composition has been described under the sponsorship of the Alloy Casting Institute,1 in which, by maintaining a substantially austenitic* alloy, optimum creep strength and minimum tendency to embrittle after aging are expected. Unless, however, the limits are undesirably dose, it has not been possible to ensure a moderate range of strength and of ductility by any chemical specification alone. There is a definite need

Jan 1, 1942

By Franklin H. Sharp, Kenneth L. Clifford

During the last few years the New Lead Belt of Southeastern Missouri has become the main source of lead in the United States. It also produces significant amounts of zinc, copper and silver. The mines are located on a narrow, mineralized trend extending southward from Viburnum, MG. for about 35 miles. The ore occurs as replacement deposits in the Bonneterre lime- stone formation which is about 1000 ft below the surface. In most of the mines, enough water is produced to supply the milling requirements without any reuse. There are dry areas, however, and at least two mills must rely on water reclaimed from their tailings lake to augment the mine water. These mills have no choice but to utilize recycled mill water.

Jan 7, 1973

By A. C. Fraker, H. H. Stadelmaier

In the systems Mo-Fe-C, Mo-Co-C, and Mo-Ni-C the phase boumdaries of the cubic Ij carbides were determined at 1000°C and the variation of the lattice parameter with composition was measured. In the system Mo-Fe-C a single ternary carbide, Mo3Fe3C, was observed. In Mo-Co-C and Mo-Ni-C two new n phases of the type M12C were found: Mo6C06C and Mo6Ni6C. At 1000°C they coexist with the M6C phases MO3-4,CO3-2C and Mo3-4Ni3-2C, respectively. Mo3C03C and Mo4C02C are not separate phases but parts of a single M6C phase region, and the same is true of Mo3Ni3C and Mo4Ni2C. THE n carbide structure type has been known since it was determined by westgren' in 1933, yet reliable information on phase compositions of this type is ap-parently scarce. The following selection of suggested formulas illustrates the extent of the confusion con-cerning compositions: W2-3Fe4-3C,1W6Fe6C,2 W2_4Fe4-2C,3 (W,Fe)6C,4 Tj.-W4Co2C and nz-W6Co6C,5 n1-W3Co3C and n2-w4Co2C,5 W3C03C and w6Co3C2,7 MO3Fe3C,8n2-M04Fe2C,9 (MO,Fe)6C,4 MO3CO3C,8 n2-MO4CO2C.9 Many of these compositions obviously overlap, some disagree in carbon content. The use of the designations 77, and n2 is not consistent. There is uncertainty whether two carbides M6C coexist or whether there is only one M6C with a wide range of substitution of one metal for the other. The existence of M12C seems questionable altogether if one ignores the results of a neutron diffraction study of W6Fe6C supporting that particular metal to carbon ratio.'' More reliable information is available for the iso-typic oxides studied by Nevitt,11 Nevitt, Downey, and orris," and Meussner and carpenter.l3 That n car-bides and oxides are structurally identical, particularly with respect to the location of the metalloid atom, has been demonstrated clearly by Stadelmaier and Meussner14 and also by Parthe, Jeitschko, and sadagopan.15 Therefore the present paper, which attempts to establish the phase boundaries of n defini-tively for three carbon systems, has implications for the whole family of filled Ti2Ni types. EXPERIMENTAL PROCEDURE The samples were prepared in two stages. Pellets weighing 3 g were compacted from powders of the elements and presintered in a closed tube of fused silica that had been evacuated to lO-4 mm Hg. This was fol- lowed by arc melting the sintered samples under argon. Remelting the button once was sufficient to produce homogeneous specimens. The metal powders had the following minimum purities in wt pct: molybdenum 99.5, iron 99.0, cobalt 99.7, nickel 99.9, graphite 99.94. Carbon determinations by the gas volumetric method were obtained from thirty-one of the one hundred samples in the annealed condition. They were limited to compositions that were critical to placing a boundary line in the isothermal sections. The carbon losses were comparatively low and averaged less than 1.5 at. pct. For annealing, the samples were sealed in tubes of fused silica evacuated to 10-4 mm Hg. The annealing schedule was 20 hr at 1250°C followed by 150 hr at 1000" ±10°C. For the water quench the silica glass tubes were broken mechanically to speed the quench. The specimens were examined in the as-cast and annealed condition by standard metallographic techniques. Some of the as-cast and all annealed samples were studied by X-ray diffraction using a 114.6-mm powder camera with filtered Co radiation. The lattice parameters of the n phases were determined by graphic extrapolation to 8 = 90 deg on a plot against sin2 8. It is estimated that the maximum error in the lattice parameters is ±0.002A.. The phase fields were determined by the disappearing phase method, relying on X-rays for phase identification and on microscopy to detect small amounts of a phase. RESULTS Pertinent information on the binary side diagrams has been summarized by Hansen and Anderko16 and Elliott17 and will not be discussed further. Photomicrographs documenting the equilibria at 1000°C have been selected to avoid redundancy due to the similarity of the three systems. Thus there will be only one picture showing an equilibrium with Mo2C, and so forth. Molybdenum-Iron-Carbon. An isothermal section of most of the Mo-Fe-C system at 1000°C is shown in Fig. 1. No attempt has been made to distinguish between a and y iron or to determine their phase boundaries. A conspicuous absence is the phase Fe2 1Mo2C6 with the Cr23C6 structure, supporting the suggestion by Krainer4 that it decomposes by annealing at high temperatures. The only ternary phase is found in a narrow range around Mo3Fe3C (MO43Fe43C14). A microstructure with a two-phase mixture of Mo + n is seen in Fig. 2. The variation of the lattice parameter of n with the estimated composition is shown in in Table IA. The phase diagram does not agree with the results of Kuo9 who reported n2-Mo4Fe2C. Our lattice parameter Varies from 11.095A at the iron-rich end to 11.140Å at the molybdenum-richoend of the phase field whereas Kuo9reported 11.26Å for Mo4Fe2C. We are in agreement with the older work

Jan 1, 1970

By J. R. Craig, T. N. Solberg, M. A. Linden

The central and southern Appalachian Mountains were the major sources of domestically produced gold throughout the first half of the 19th century and continue to yield gold today. Small amounts of gold were probably extracted by the Indians and the Spaniards but the first documented report of gold in the region was made by Thomas Jefferson who found, in the Rappahannock River of Virginia in 1782, a 1.8 kg (4 lb) lump of gold ore that yielded 26 g (0.85 oz). Gold was subsequently discovered in North Carolina between 1793 and 1799, in Virginia in 1806, in South Carolina in 1827, in Georgia in 1829, and in Alabama about 1830 (Becker, 1894-5; Pardee and Park, 1948). Production climbed to more than 933 kg/a (30,000 oz per year) between 1830 and 1852, but dropped sharply after the California gold rush in 1849 as experienced miners moved west in search of bigger and easier stakes. The Civil War briefly halted gold mining in the Appalachians, but production rose to an average of about 249 kg/a (8,000 oz per year) from 1865 until 1878 and to about 404 kg/a (13,000 oz per year) from 1881 until 1915 when it again fell to near nil (Pardee and Park, 1948). Minor resurgences occurred in the 1930s and 1940s. Although there has been no reported production in recent years, it is likely that "weekend panners" still remove hundreds of ounces from streams annually. The total reported production for the area through 1959 is more than 77 t (2.5 million oz). This paper reports some initial findings of a long-term project designed to investigate the mineralogy, chemistry, mode of occurrence, and petrology of gold occurrences in the Appalachians. The goal of the initial phase was to determine the compositional range of gold in the Appalachians as a step toward deciding if sufficient variations were present to allow the definition of "compositional signatures." The very few published data on gold fineness in the Appalachians are based on assays that commonly include gold and silver from several mineral species. Analyses in the present study were performed on individual grains of electrum using a spot size of 10 µm x 10 µm to 100 µm X 100 µm (394 X 394 micro in. to 3,940 X 3,940 micro in.), and thus reveal the true composition of the principal precious metal-bearing phase.

Jan 1, 1984

By M. M., Fine

In a laboratory study of grinding and classification' of silica sand, a satisfactory means of producing the medium-fine specification sand desired by producers of flint-glass containers was developed. The best procedure consisted of ball-mill grinding and double classification, which gave a properly sized sand containing less iron than the feed.

Jan 1, 1950

By H. M. Otte, A. G. Crocker

SLIP, twinning, stacking faults, and precipitates on well-defined planes in a crystal produce traces that are visible on either a polished or an etched surface. The purpose of this note is to establish the usefulness and limitations of the information obtained from such traces when determining the orientation of single crystals or grains in a polycrystal. Attention will be confined specifically to traces produced by octahedral planes in cubic crystals, though most of the remarks can be taken as more generally valid. The problem of determining the crystal orientation is completely solved in principle' and in particular for the special case under consideration.1'2 Tables are available3 in which the orientations can simply be looked up when given the two or three angles between the traces. Thus a quick and simple method is available for obtaining the orientation of a crystal from surface traces. In this note two examples will be given from recently published papers and will show the use of the method with the aid of the Tables, as well as some of the precautions that should be taken in the procedure. As part of an analysis of X-ray Kossel lines, Peters and Ogilvie 4 determined from them the crystallographic orientation of the specimen. They chose a Cu-5.10 wt pct Si alloy that had been partly transformed from the a (fee) phase to the k (hcp) phase. The latter formed as very straight platelets along the octahedral planes of the a phase, and a photograph (Fig. 7 of Ref. 4) was reproduced in the paper4 of the region for which the orientation had been determined from the Kossel lines. Apart from a very small area (about 0.15 mm diam) near the top center of the photograph, the region shown was clearly all of one orientation. Traces in four different directions were readily identified. Starting with the smallest angle and proceeding counterclockwise, the angles between the traces were measured to be 27° 43', 55° 16', 64 3 43 1, and32"26'. These add up to 1802 08 1, indicating a cumulative error of 8'. The correct values should, of course, be taken from the original glass plates, or at least from prints on distortion-free paper, so the precision of the quoted values is actually greater than their accuracy. The solutions can be looked up in the Tables3 in four ways, depending on how the angles are paired, tion for the minutes of arc is required and the solution obtained will be identical for all the four pairs if the values of the angles are not in error. In a practical situation, such as this one, there are several sources of error, so that the four solutions obtained will all be slightly different. An arithmetic average of the four solutions is mathematically incorrect, but may, in special cases, give an answer close to the correct one. A rigorous procedure for refining the orientation has been described by Mackenzie;5 he gives a least-squares method that can be applied, if necessary, to this type of problem. The orientation thus determined can be compared with the one from the Kosel lines and discrepancies larger than the experimental error assigned to nonor thogonality of the X-ray or electron beam to the specimen. Here the example will only be used to illustrate the general procedure for making a very rapid rough check. From measurements on the stereographic projection, Fig. 9 of the paper,4 we can determine that the surface normal is approximately (0.434, 0.704, 0.562). From the Tables3 we find, using 28°, 55" as a good approximation to the first pair (27°43', 55°16'), that the surface normal is (0.453, 0.678, 0.579).* These two values are within 2 deg of each

Jan 1, 1967

By Edward H. Robie

MANY engineers currently are working harder than usual, in part because of the demands being made upon them for increased production in the war effort, and in part because engineers are in short supply so that there is more to do for those who are available. In some instances the question has come up as to what additional payment, if any, should properly be made for overtime work, and to what extent is such payment legally permitted under the rules of the Salary Stabilization Board. Most engineers employed in an executive, administrative, or outside salesman capacity are not paid for overtime. They are paid for doing a job instead of for the hours they put in, and are free to do all the unpaid home work they feel they should do after dinner, as well as to do a bit of thinking and worrying during wakeful hours in bed. But engineers employed in a strictly professional capacity normally have standard office hours. Some employers pay for overtime and some don't. Their practice as it existed on Jan. 25, 1951 may be continued. In the absence of such practice at that time, the Salary Stabilization Board says that the engineer may now receive additional compensation up to his straight-time rate for an extended work week. No formal approval of the Board is required. "A professional engineer," in the mind of the Board, "is a person employed in a professional capacity, who, by reason of his special knowledge of the mathematical and physical sciences and the principles and methods of engineering analysis and design, acquired by professional education and practical experience, is qualified to practice engineering." Inducted Engineers A letter from a young man just inducted into the service and fearful that his engineering training is not going to be utilized reached us last week from Fort Riley, Kan. The AIME, cooperating with the other Founder Societies, is doing what it can, through the Engineering Manpower Commission, to see that engineers are not being wasted in the military establishment. So we passed this young man's letter along to T. A. Marshall Jr., executive secretary of that Commission. Mr. Marshall tells us that the normal procedure now being followed by the Army in handling Selective Service inductees is to have them first complete 16 weeks of basic training before assignment to specialized categories. During that time they are classified. If one has an engineering degree he should be classified as scientific and engineering personnel at the end of the basic training period. He should then be transferred to a technical detachment and assigned an MOS (Military Occupational Specialties) reflecting his education. If a young man is looking for a commission, it might be added that the current policy in the Army is to transfer to OCS (Officer Candidate School) applicants for commissions in the infantry only. The local unit commander can give information on this point, based upon the aptitude shown in tests. In view of the current shortage of engineers, it is believed that a young man should seriously consider remaining in enlisted status unless he can obtain a commission in a branch of the service that can make full use of his technical skills. His work may thus be more to his liking even if his uniform is not. New York or Atlantic City? In which place is it preferable to hold the annual meeting of a professional society like the AIME-New York or Atlantic City? That is, a winter meeting. The American Society of Mechanical Engineers has held its recent meetings at Atlantic City, with increasing attendance and satisfaction. The American Institute of Chemical Engineers chose Atlantic City for its recent December annual meeting. Only twice has the AIME ever met in this famous seashore resort: in 1898 and 1904. Chief advantages of going to Atlantic City over New York are that technical sessions are better attended, there being little else to do there in Winter; the cost to members is less, and hotel facilities are better adapted to a large meeting. As to cost, take a banquet, for instance. The Chalfonte-Haddon Hall, which caters especially to winter conventions, charges about $7 for a banquet dinner of standard quality. A similar dinner at the Statler in New York would cost about $8.50, and about $10.50 at the Waldorf-Astoria. (The charge for tickets is somewhat greater than this because of the cost of music, programs, flowers, and other incidentals.) Rooms, too, are somewhat less at Atlantic City, two in a room being accommodated for about $7 per day each, compared with $7 to $10 at a headquarters hotel in New York. On the other hand, AIME headquarters is put to some extra expense for staff travel, food and lodging, and members living in New York and environs are forced to pay a hotel bill. New York, of course, has more varied amusements to offer, plenty of big stores, and the glamour of a big city. The choice may be discussed at the forthcoming meeting in New York. In the meantime if any reader cares to express an opinion one way or the other we shall be glad to hear it. College Scholarships Most parents of children in the later stages of high school find it necessary to give some consideration to the cost of a college education. Although salaries have increased substantially it seems that the cost of the necessities of life, such as food, housing, and maintaining the family automobile, have gone up even more, so the problem of financing the children's education is as acute as ever. Many overlook the possibility of scholarships, or feel that only a student at or near the top of his class has a chance to get one. As a matter of fact, close to 150,000 scholarships and more than 15,000 fellowships, worth some $42,000,000, are available in 1200 American colleges and universities. Those who are interested should send 55¢ to the Superintendent of Documents, Government Printing Office, Washington 25, D. C. for a 248-page publication just issued by the U. S. Office of Education, entitled "Scholarships and Fellowships Available at Institutions of Higher Education."

Jan 1, 1952

By S. W. Miller

Most of the steel welding done at the present time is in material containing not over 0.3 per cent. carbon, and the tests here described were in similar material. These tests are not as yet completed but it is hoped that more results and more reasons for the conclusions may be presented at the meeting in February. From the time the author found the peculiar structure in electric welds referred to in a previous paper,' that is, needles or plates in the grains and similar material, in larger spots, at the grain boundaries, he has felt that these plates which may be iron nitride and probably contain some carbon, were at least partly responsible for the brittleness of electric welds. He has found but few traces of similar lines in oxyacetylene welds until the last 2 mo., he has since found large numbers under certain conditions. In the top of these welds, they are quite numerous. In the body of heavy oxyacetylene welds, they appear at times, but not nearly to the extent that they do in electric welds; the author has never seen them in the body of welds in material less than % in. (19 mm.) thick. They are shown in Fig. 82. The reason they were not noticed before is undoubtedly due to the fact that in making tests of welded pieces the weld was always ground off level with the plate, and as this structure only appears in the top 1/16 in (1-5 mm.) of the weld, they were removed by the grinding or machining; also, welds 3/4 in. thick had not been examined. It did not appear, in making bending tests, that this structure had much influence on the strength of oxyacetylene welds; while electric welds are noticeably brittle. Further, oxyacetylene welds made with certain special materials were exceedingly brittle even after the tops of the welds were removed; this was true in cases where there was no sign of the plates whatever and where the welds were remarkably free from oxide and the other usual defects. It appeared, therefore, that this brittleness did not depend on any variable that had been noticed so far, and it was decided to find where the rupture occurred in various kinds of welds made

Jan 1, 1920

By Arthur Zentner

THE essentials of the electrolytic zinc process, as now used in commercial plants, date back to work done by Letrange in 1881. He used sulfuric acid to leach roasted sulfide and ,oxide ores, purified his solution very much as we do now, and electrolyzed the purified zinc sulfate solution. Ten years later Hoepfner developed a process using chloride solutions, and built three plants. One in England operated until 1924 in one of the works now merged in the Imperial Chemical , Industries, Ltd. Ashcroft built a plant in 1898 in the Broken Hill district of Australia. He used both chloride and sulfate solutions.. While his work failed, the aid his published results have been to later workers has made him an outstanding contributor to the de- velopment of the electrolytic zinc process. A good deal of work was done in the following years, aiming to electrolyze zinc chloride solutions and fused zinc chloride. Quite a bit of work on sulfate solutions was also done in the last years before the war. With the outbreak of the war, metal demand and rise in metal prices provided the stimulus which resulted in the remarkably rapid commercial development of electrolytic zinc. In this last period of development, all the work brought to commercial fruition has been with sulfate solutions. The high-density process, or the Tainton process, is used, as you know, in the Sullivan electrolytic zinc plant at Kellogg, Idaho, and will be used in the Evans- Wallower plant now being built at East St. Louis. The low-density process is used by the other plants now operating in the United States and other countries. There are now in operation and under construction four electrolytic zinc plants in the United States, two in Canada, two in Italy and one each in Australia, Rhodesia, Poland, Norway and Germany.

Jan 1, 1929

G. A. Moore—The tin-fusion method has been a very favorable possibility for many years. The authors apparently have settled the question that delayed the method for a long time by showing that no hydrogen is absorbed in the tin. This, of course, is very important. I want to make a few remarks concerning the absolute accuracy of analysis, which must be the final basis for deciding among the various methods. From the figures in the paper, there seems to be some re-maining slight discrepancy on the actual amount of hydrogen present in various samples which may be presumed essentially identical. (This is of the order of the precision of individual analyses but appears in averaged results.) From the analyst's viewpoint, the tally of hydrogen content can be regarded as occurring in three portions. First is a large portion which comes off easily and automatically during sample storage and later on heating in the apparatus. This is fairly easily analyzed. Second is an item which may be either positive or negative in the tally sheet. In warm or hot evolution, this is a portion which, in practice, can never be re-

Jan 1, 1951