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By E. M. Norris

THE Western phosphate deposits extend over a large area in the Rocky Mountain region, comprising portions of south central Montana, southeastern Idaho, northeastern Utah, and southwestern Wyoming. A limited acreage of these deposits passed into private ownership prior to Dec. 9, 1908, at which time 7000 sq. mi. of land in these phosphate fields was withdrawn from public entry by direction of the Secretary of the Interior. Under the Act of Feb. 25, 1920 (41 Stat. 437) title to all phosphate lands in the public domain was reserved to the United States with provisions for leasing portions to citizens, corporations, states, etc. The above act, in effect, created by law a Western phosphate reserve of approximately 2,269,055 acres.

Jan 1, 1944

By R. C. Mahon

During the early history of the Lake Superior district, tamarack timber was used almost exclusively in the wines. It had the strength and lasting qualities necessary for a satisfactory mining timber. But about fifteen years ago the tamarack trees were attacked by a blight which killed nearly all of them so today no tamarack timber is available. Hemlock, spruce, and poplar have neither the necessary strength nor the lasting qualities for mining timber, but a large supply of maple and birch is available. These have ample strength but, when placed underground, fail by decay in about three years. This means that, instead of replacing the timber sets once in fifteen years, it must be done five or more times in the same space of time which involves not only incraesed timber costs but more important, an increased labor cost.

Jan 1, 1949

By W. Rostoker, R. P. Elliott, B. W. Levincer

Phase equilibria in the Ti-Cr-Mo system have been investigated for alloys containing 100 to 40 pct Ti in the temperature range 550° to 1300°C. Five experimental isothermal sections and a surface of incipient melting are presented in addition to a summary projection of the space. Seven vertical sections have been constructed from the isothermal sections. A STUDY of the system Ti-Cr-Mo was undertaken as part of a program sponsored by Watertown Arsenal toward the development of titanium-base phase equilibrium diagrams of potential technical importance to alloy development. The scope of the investigation included the composition range contained by the titanium corner and the line of 64 pct Ti (all compositions are by weight) and the temperature range 550" to 1100°C. A surface of incipient melting was constructed from measurements on a large number of alloys. The system Ti-Cr has been established.&apos;-? The phase diagram is characterized by a wide miscibility field of the solid solution at elevated temperatures and a eutectoid reaction of the type: (15 pct Cr) + TiCr, (685C). The a solid solution has a very limited capacity for solution of chromium (< 0.5 pct Cr). The intermediate phase TiCr2 has at best a very narrow composition range. It has been shown that two allotropic modifications of this phase exist. However, this behavior does not appear to be perceptibly reflected in the form of phase boundaries of the type + TiCr,. In the system Ti-Mo,9-10 the phase is stabilized to successively lower temperatures with increasing molybdenum content. There are no known intermediate phases. The a solid solution is limited to less than 0.5 pct Mo. Because of the very extensive range of the phase, the ternary system was ideally suited to the determination of the phase boundaries by the parametric method of Andersen and Jette." A parametric surface was constructed to provide the necessary basis for the application of this method. Preparation and Treatment of Alloys More than 60 alloy compositions were prepared for the study of this system. Alloy buttons of 10 grams were arc-melted in a nonconsumable electrode furnace using inert atmosphere protection and a water-cooled copper crucible. The construction and operation of this type of melting unit have been adequately described elsewhere.&apos;&apos; To insure complete solution of alloy additions, the buttons were remelted alternately on top or bottom as many as five times. This was accomplished by a suitable mechanism for "flipping" over the ingots. Iodide titanium (99.97 pct Ti) was used as the alloy base. An especially high quality chromium (99.9 pct Cr) was obtained from the National Research Corp. Molybdenum sheet (0.005 in.) of 99.9 pct purity was used.

Jan 1, 1954

By E. F. Ketterer, D. B. Collyer, A. B. Wilder

AISI constructional alloy steels are a series of steels in which a numbering system signifies the chemical composition limits. SAE (Society of Automotive Engineers) and AISI (American Iron and Steel Institute) use basically the same numbering system. The steels contain, in part, alloy additions of chromium, molybdenum, nickel, and vanadium. They are used widely in the automotive industry but have not been adopted for high temperature service. The purpose of this investigation was to study changes in microstructure observed in typical AISI constructional alloy steels in the welded and un-welded conditions after exposure for 34,000 hr at 900" and 1050" and, in several instances, 1200°F. The tensile and creep rupture properties after exposure for 10,000 hr were also evaluated. The investigation is a continuation of the work previously discussed. Little was known concerning the existence of graphite in medium or low carbon steels before 1943. It is important to note that continued exposure at elevated temperature is required in order to develop graphite in steels. Interest in the presence of graphite in steel, and also in changes in the properties of steels after long service at elevated temperatures, developed after 1943 when a failure of a welded joint of high temperature piping was associated with the graphitization of a relatively low carbon content steel with 0.50 pct Mo,8,0 Numerous investigations have beeen made in recent years studying the relationship of this type of failure to changes in properties. Attempts have been made to evaluate the performance of a number of steels, particularly in the heat-affected zone of welds. It was the unfortunate failure of a weld-heated zone in high temperature piping in the steam-power industry which focused attention upon possible failures, and upon the need for improved steels for high temperature piping service. Investigation by the National Tube Div., U. S. Steel Corp., Lorain Works, has included a wide variety of steels in an attempt to learn the effects of numerous factors and elements upon the long time performance of steels, although many of the compositions studied will never be used at elevated temperatures.1,4-7 Included were the well established AISI steel series, which offered opportunity to test moderately high carbon content steels as well as observe the effect of nickel, chromium, molybdenum, etc., upon the properties of these well known steels. The properties of the AISI steels were also studied for comparison with the previously reported properties of the Cr-Mo steels, now used by the steam-power industry.5,7 Materials and Testing Procedure The AISI alloy steels in Table I were exposed for 10,000 and 34,000 hr at 900°, 1050°, and 1200°F.

Jan 1, 1958

By John Gross

THE deductions drawn in crushing and grinding operations have heretofore been based on a separation of the products into various sizes. A crushed product may be sized by sieving, by elutriation, and by aid of the microscope. To estimate the surface of each size the relation of the surface to the estimated average diameter must be assumed. Such a relation, owing to the irregularity of the particles, may involve two assumptions: First, a factor to convert average diameter to surface for one particular size; and second, a variation in the factor as the diameter of the particle changes. Obviously a surface measurement in which such assumptions and estimates are involved is questionable. In the first paper of this series1 a method has been given by which an accurate measure of surface of quartz can be obtained from its dissolution rate. By the use of this method, surface measurements have been made on a series of sieve sizes of crushed quartz, the results of which are given and discussed in this paper.

Jan 1, 1928

By Oliver C., Ralston

THE following data were obtained during Tan exhaustive research into the possibilities of concentrating United Verde massive sulfide copper-zinc-iron ores by flotation. The composition of these ores approximates the following mineralogical analysis: 3 to 15 per cent chalcopyrite; 3 to 11 per cent marmatite (ferruginous sphalerite) ; 47 to 69 per cent pyrite; and 10 per cent quartz. The remainder is usually schist gangue. The sulfide minerals are finely dis-seminated; chalcopvrite and marmatite begin to be liberated on grinding at about 100 mesh, but complete liberation from gangue (pyrite in this case is considered a gangue mineral) is

Jan 1, 1935

By C. R. Boyd

In 1874 I received an appointment in the corps organized by Col. William P. Craighill, U. S. Engineers, to survey the New or Upper Kanawha river for the purpose of ascertaining the practicability and

Jan 1, 1895

By Leo Horvitz

PETROLEUM and natural gas are composed principally of the saturated hydrocarbons ranging from methane, the lightest, to nonvolatile liquids and solids containing approximately thirty-five carbon atoms. A technique for locating buried accumulations of these hydrocarbons before drilling obviously requires that some of the hydrocarbons leave the deposit and migrate toward the surface of the earth where they may be detected in their original form. Earliest attempts to link near surface hydrocarbons to petroleum at depth were apparently made by Laubmeyer1 in Germany and by Sokolov2 in Russia. These investigators collected samples of soil air from boreholes one to two meters deep and analyzed them for traces of hydrocarbons. They found that soil air over producing areas is richer in these constituents than is soil air over barren areas.

Jan 12, 1954

By Philip E. LaMoreaux

Fluoride, generally less than 0.5 ppm, is present in ground water from rocks of Paleozoic age and older, in northern and eastern Alabama. Some of the water-bearing formations in the Coastal Plain area of the State yield water with as much as 6.8 ppm fluoride.

Jan 8, 1950

By Eugene McAuliffe

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

Jan 1, 1931

By T. E. Leontis

Data are presented in this paper to show that addition of zirconium to sand-cast Mg-Th alloys effects a marked decrease in the grain size of these alloys which is accompanied by a significant increase in the mechanical properties over the entire range of thorium content investigated. The beneficial effect of zirconium on the strength properties is maintained at elevated temperatures up to 700°F. In addition the alloys exhibit exceptionally high creep resistance at temperatures up to 600°F. Zirconium does not greatly improve the strength or creep characteristics of extruded Mg-&apos;Th alloys. Cerium is not a desirable addition to Mg-Th-Zr alloys. IN a previous paper,&apos; it was shown that addition of thorium to magnesium imparts exceptionally high resistance to creep at elevated temperatures both in the sand-cast and in the extruded states. The large grain size of the sand-cast alloys, however, renders them of questionable value as engineering materials. Sauerwald² showed that the grain size can be reduced effectively by the addition of zirconium. Results of a detailed study of the properties of Mg-Th-Zr alloys over a wide range of thorium content are presented in this paper. In accordance with the preliminary findings of Sauerwald,² it is shown here that Mg-Th-Zr alloys possess the unusual combination of fine grain size and a high level of strength and creep resistance at elevated temperatures. Some information on the effect of cerium on the properties of Mg-Th-Zr alloys is presented also. Effect of Th on Solubility of Zr in Molten Mg Sand-cast test bars and 3 in. diam extrusion billets of Mg-Th-Zr and Mg-Th-Ce-Zr alloys* were pre- pared according to the procedures described in the previous paper.&apos; The zirconium was added in the form of sponge metal as supplied by the Bureau of Mines.&apos; The maximum amount of zirconium that usually can be introduced into magnesium at the customary alloying temperature of 1350° F is about 0.7 pct. The analyses in Table I clearly show that thorium in- creases the solubility of zirconium in liquid magnesium. The tabulated zirconium contents are designated as "acid soluble;" this serves to distinguish these values from the small amount of zirconium that is not dissolved when the alloy is subjected to the action of a dilute acid solution. The "acid-insoluble" zirconium is believed to be ineffective as an alloying ingredient. The acid-insoluble zirconium contents ranged between 0.03 and 0.16 pct in the present alloys, the tendency was toward higher values in alloys with higher thorium content. In contrast to the effect of thorium, cerium decreases the solubility of zirconium in magnesium. This is shown by the three Mg-Th-Ce-Zr alloyst in- cluded in Table I and stands in agreement with the observations of Nelson and Stricter".&apos; on Mg-misch-metal-Zr alloys. Effect of Zr on Grain Size of Mg-Th Alloys The potent effect of zirconium as a grain refiner has been demonstrated for many types of magnesium alloys.3-8 Of greatest importance to date are Mg-Zn-Zr alloys5,6,8 and Mg-mischmetal-Zr alloys.3,4,7 Zirconium has also been found to exert a marked grain-refining action on Mg-Th alloys. All the Mg-Th-Zr alloys cast in the form of ½ in. diam test bars have an exceedingly fine grain size (Table I). Reference to the previous paper&apos; will show that binary Mg-Th alloys containing up to 6 pct Th are almost completely columnar even in the M in. diam reduced section of a test bar, and that 10 to 50 pct Th alloys have an equiaxed grain structure of 0.03 to 0.08 in. The data in Table I also show that addition of cerium to Mg-Th-Zr alloys has no effect on the grain size. In addition to increasing the strength properties, the fine grain size of Mg-Th-Zr alloys

Jan 1, 1953

By E. R. Shorey

FLOTATION-Mill operator&apos;s have recognized that slimes are detri-mental to the flotation concentration of zinc ores. The, presence of primary slime in many of the Wisconsin ores is largely responsible for the failures experienced in treating these ores by flotation. These failures have discouraged the adoption-of the flotation process by opera-tors in the Wisconsin zinc district. The removal of slimes by decantation seemed to be the obvious way to meet the problem of treating slimy or&apos; clayey ores by flotation. To facilitate the removal of slime, it was decided to mix the ore pulp with sodium silicate, which acts to deflocculate the pulp.1 Deflocculation causes slime suspension, making it possible to separate the slime from the sands by decantation.2 Since the literature contains little definite information on the use of sodium silicate to deflocculate ore pulps, a series of tests was conducted to obtain the necessary information. Tests to determine the settling rates of sand and slime in deflocculated pulps were conducted on a dolomite-marcasite-sphalerite ore ground to minus 80 mesh (175 microns) and mixed with water to form a pulp. The deflocculator3 was Mallinckrodt 40° to 42.5° Bé. liquid sodium silicate (Na20 + 3.25Si02). .By microscopic analysis the suspended slimes4 were found to be minus 15 microns (approximately 1000 mesh).

Jan 1, 1934

By Robert Forsyth

IN working the Bessemer process, the bottom of the converter has always been a source of trouble and annoyance, and the subject of more experiments, probably, than any other part of the complex mechanism called a Bessemer plant. This will not appear remark- able when the duties this important piece of refractory material has to perform are taken into consideration. In the first place, by means of the tuyeres, it delivers at a high pressure the air necessary for the conversion of the bath of metal, and has then to resist the intense

Jan 1, 1876

By R. D. Nelson

The purpose of this technical note is to briefly present some data on a phenomenon—recrystallization with concurrent deformation—that has been found to occur in a plutonium. This phenomenon is unusual because a plutonium is considered brittle, not easily deformed, and not easily recrystallized; the a phase is simple monoclinic having 8 atoms per unit cell and it is stable below about 115°C. The properties of the recrystallized metal were different from the as-cast metal. Even though a plutonium is difficult to deform, Ianniello successfully rolled it&apos; and he also observed some recrystallization at 120°C.2 Pavlick and Hanson3 detected some recovery at 109°C but they observed no recrystallization. Gardner4 and Bronisz5 studied the compression properties up to 100°C but they did not report having seen recrystallization. In the present deformation studies of electrorefined plutonium pronounced recrystallization took place concurrently with plastic deformation in compression between 24" and 115°C. The metal contained less than 300 ppm total impurities with the major impurities being 100 ppm Am, 30 ppm C, 40 ppm W, and 25 ppm U; all other impurities totaled less than 100 ppm. The compression specimens were machined to dimensions of 1.2 cm long and 0.8 cm diam from as-cast rods having a density of 19.65 g per cu cm. They were heated to the test temperature in a high-temperature silicone fluid that was evacuated to 10-4 Torr. With this procedure the specimens oxidized a negligible amount, and the temperature was maintained within ±0.2°C for times up to 3 weeks. Deformation and recrystallization

Jan 1, 1969

By Robert G. Van Nostrand, John H. Henkel

TRANSIENT potentials obtained in resistivity prospecting can be separated into two classes. The first is electromagnetic, has a comparatively short time constant, and increases in relative amplitude as the electrode separation is increased. These electromagnetic transient potentials, of which an excellent theoretical treatment is given by Yost,1 are the result of changes in the current and can be classed as differentiated signals. The second class is electrochemical, has a comparatively long time constant, and decreases in relative amplitude as the electrode separation is increased. The electrochemical signals are generated by the current flow itself and can be classed as integrated signals. The transient potentials due to electrochemical factors are the subject of this article. The phenomenon is referred to as induced polarization. Schlumberger2 was the first worker to observe induced polarization, but he was unsuccessful in attempts to apply the principles of induced polarization in electrochemical prospecting. Other workers, notably Bleil3 have studied polarization and in some cases pointed out its possibilities, but no theory has been presented that describes polarization and its time dependence adequately. It is the purpose of this discussion to present the essence of a theory to geo- physicists and to show that it leads to results consistent with experimental evidence. The theory on which this analysis is based has existed in electro- chemical circles since 1910.4

Jan 3, 1957

By John H. Hollomon

IN recent papers, O&apos;Neill,1 Vivian,2 and Zener and Hollomon3 have reviewed some of the information concerning the relations between stress and strain during plastic deformation. Since further information has been obtained since these reviews were published, this paper attempts to further coordinate and amplify the knowledge concerning the plastic deformation of metals in simple tension. Ordinarily the results of tensile tests of metals are presented as graphs in which the load divided by the original area is plotted as a function of the percentage of elongation measured over some specified gauge length. The interpretation of graphs of this sort is limited, since the stress required to deform the metal at any stage of the deformation is actually the load divided by the instantaneous rather than the original area. Furthermore, each increment of the deformation is performed on metal that has been previously deformed, and, as pointed out by Ludwik,4 the strain could be more effectively defined: [e = In A t][I] where a is the strain and Ao and A are, respectively, the original and instantaneous areas. The results of the tensile tests can be more effectively presented and interpreted if the stress* (load divided by actual area) is plotted as a function of the strain as defined above. A schematic curve of this type is presented as Fig. I. In a previous paper,6 the concept of Ludwik7 concerning the flow and fracture of metals was successfully employed to explain some of the puzzling results of notched-bar impact tests of steel. It appears that the use of this concept is very fruitful and should be kept in mind in any study of the deformation characteristics of metals. Ludwik considered that a flow stress-strain curve of a metal was essentially a locus of points that described the stress required for plastic flow of an infinite number of specimens, each with a different strain history determined by the preceding part of the flow curve. Each of these specimens can also be considered to have a fracture strength. Unfortunately (or fortunately depending upon the point of view), all the specimens, except the one deformed to the fracture strain, flow and do not fracture. Even though the metals do not fracture, the concept of a fracture-strength curve seems

Jan 1, 1945

The Climax Molybdenum Company&apos; s newest operation is the Henderson project, which is located on the east side of the Continental Divide. Ore reserves are estimated at more than 300 million tons at a grade of 0.49% MoS2. For mining the ore a modified panel caving system is used. The ore is transported to the Henderson mill on the west side of the Continental Divide on a 42 in. (1.07 m) gauge railroad through 9.6 miles (15.4 km) of tunnel and 4. 8 miles (7.7 km) of surface track, a total distance of 14.4 miles (23. 2 km). Each train consists of 30 ore cars with capacity of 22 st (20 mt) of ore or 660 st (599 mt) per train. The unmanned trains operate completely automatically. At the 54 in. by 84 in. primary gyratory crusher, the bottom dump ore cars pass over a dump scroll to discharge at a maximum rate of 100 st (91 mt) per minute. Dumped ore falls onto a rock box before passing over a 17 ft long by 46 ft wide (5. 2 m by 14 m) grizzly set at a 40° angle with bar spacings of 7 ½ and 8 ½ in. (191 mm and 216 mm) openings. An estimated 30 to 50% of the ore (which at times is wet and sticky) passes through the grizzly. The operators report that a shallower angle on the grizzly, perhaps 35º to 37º, would have been sufficient and would have prevented impact on the back of the crusher pocket by large boulders. This pocket as well as the crushed ore pocket under the crusher is lined with AR plate. The accompanying drawings show a "future splitter" and the operators are planning the installation of this unit to prevent impact and subsequent damage to the crusher spider. Crushed ore at an 8 to 9 in. (203 mm to 229 mm) size joins the grizzly undersize in the pocket beneath the crusher. This pocket is sized at 660 live st (599 mt) so that it will accept an entire trainload of ore. Crushed ore is removed from the pocket by a four-speed, 84 in. (2. 1 m) apron feeder operating at 9.6 to 29. 3 fpm (2.9 to 8.9 mpm). A 60 in. (1.5 m) takeaway conveyor operating at 480 fpm (146 mpm) delivers the crushed ore to a 58,000 st live and 193,000 st total (52,600 and 175, 100 mt) open stockpile under an A -frame supported tripper gallery. Impact idlers on the takeaway conveyor under the apron feeder discharge are mounted on wood blocks for a cushioning effect and ripped belt detecting bars are located behind each impact idler. The conveyor tunnel is of corrugated and galvanized steel construction rather than concrete. The concrete crusher enclosure is circular in design from its lowest level at elevation minus 110 ft 4 in. (minus 33. 6 m) to elevation

Jan 1, 1978

By R. E. Lindstrom, D. G. Peterson, H. J. Heinen

Alkaline alcohol solutions were investigated by the Federal Bureau of Mines for improving the desorption rate of gold and silver from metal-laden activated carbon generated in gold processing circuits. Factors affecting the desorption, such as temperature, alcohol content, type of alcohol, and alkalinity, were studied. Nearly complete metal desorption was obtained in 5 to 6 hr at 80º C using a solution containing about 20 vol-pct alcohol and 1 pct sodium hydroxide. Sodium sulfide was shown to be effective for selectively precipitating silver from the carbon strip solutions, thereby providing a means for producing high- purity gold by subsequent electrolysis.

Jan 1, 1976

By AIME AIME

AN ENGINEER with as varied geographical experience as H. J. Brown does not often specialize on one particular thing all of his professional life. For forty years he has been engaged in gypsum mining, manufacturing, plant design, construction, and operation. Not only is it his work, but he says it is his hobby as well, though membership in three yacht clubs might belie that statement. New England&apos;s new representative on the A.I.M.E. Directorate, who was born in New York, Dec. 20, 1879, went to the Lawrence Scientific School at Harvard at the turn of the century. He tried journalism for a year, with the Boston News Bureau and associated financial

Jan 1, 1940

By O. M. McRae. Discussion by R. W. Jones

R. W. Jones (Senior Exploration Geologist, Standard Oil Co. of California, Box 250, Seattle, Wash.) -Mr. McRae6 and his colleagues are to be congratulated for providing a more coherent structural synthesis of the complex structure in the Courtland-Gleeson area, Cochise County, Arizona, than the "gigantic thrust breccia" concept of Gilluly. 4 However, a few problems of interpretation remain. It is the intent of this note to point out some of these problems, and, drawing on my own work in the area as well as the work of McRae6 and Gilluly, 4 to suggest some interpretations which differ from those previously published. GRAVITY SLIDES In an unpublished manuscript (Jones5) I previously argued that most of the complex structures in the Courtland-Gleeson area can be most reasonably interpreted in terms of gravity sliding caused by uplift and eastward tilting of Jurassic intrusives and associated Paleozoic rocks. Although the field work and drill hole data described by McRae6 provided excellent documentation for two important gravity slides, McRae6 interpreted the basic structure in the Courtland-Gleeson area in terms of major eastward directed thrusting. I continue to disbelieve the

Jan 1, 1967