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By Charles R. Isaacs

In 1972 Kennecott Explorations, Inc. conducted a three month cruise to the central Pacific as part of a study of deep-ocean manganese nodules. One of the objectives of the voyage was to collect at least 200 tons of nodules for use in extractive metallurgy research and various engineering tests. It was determined to cut off production at a maximum of 200 tons, should we reach that amount before the end of the 38 on-station days. We were able to reach that goal; 200 tons of nodules were collected, representing an average return of 2340 lb from 171 dredge runs. Once equipment and techniques were refined, normal returns consistently exceeded 2 tons per haul. Up to this time, Kennecott had sampled extensively with the use of small free-fall devices using wire rope and winch equipment. These devices have never offered a viable method for collecting nodules in bulk, and we sought to develop a dredging capability which would give some assurance of meeting future requirements with efficiency and economy. After testing a series of increasingly complex dredge designs at sea, it was decided to utilize two of the simpler configurations, which after modification provided the basic design for the dredge used.

Jan 4, 1974

By Joseph M. Locke

The discovery of this asphaltum was made by S. H. Gilson, of Salt Lake, and since then the material has borne the local name of Gilsonite. So far as I have been able to ascertain, however, the first published notice of this discovery was made by Prof. W. P. Blake in the Engineering arid Mining Journal, of December 26, 1885, where he names the new mineral Uintahite, from the place of its discovery, the Uintah Mountains in eastern Utah. The priority of publication and the geographical fitness of the name will probably secure its acceptance by mineralogists.* The following is Prof. Blake's article. In the month of September last, a sample of peculiar asphalt was received for examination, and recently when in Provo, Utah, I had the opportunity of seeing a considerable quantity brought in from the Uintah Mountains. It is obtained in masses several inches in diameter, and apparently free from mechanically disseminated impurities. It breaks with a conchoidal fracture, is very brittle, and is readily reduced to powder in a mortar. Hardness, 2 to 25. Gravity, 1.065 to 1.070. Color, black, brilliant, and lustrous; streak and powder, a rich brown. It is a non-conductor of electricity, and is electrically excited by friction.

Jan 1, 1888

By R. D. Nelson, D. H. Polonis

ThE eutectoid decomposition of 6 phase in the Cu-Sn system (32.53 wt pct Sn) has been studied by several investigators.1-6 On the basis of X-ray work, Iball and 0wen1 reported complete decomposition of 6 in powder specimens after 7 days at 300°C. Wang and Hansen followed the micro-structural changes during heat treatment of lump specimens and estimated 5 pct decomposition after 63 days at 300°C. Wang and Hansen suggested that the discrepancy between the decomposition rates of powder and lump specimens might be due to the excess surface free energy of powders. The present work involved 6 decomposition in copper-tin alloy powders containing 32.6 wt pct Sn. Alloy lump specimens exhibited entirely 6 phase after fairly slow cooling (air cooling) from above 350°C and were so brittle that they could be easily crushed to-200 mesh in a percussion mortar. X-ray diffraction study of the as-crushed powders (-200 mesh) revealed 100 pct 6 phase with very slight line broadening effects due to strain introduced by crushing. Only 6 phase was detected by X-ray diffraction in powders which were heat treated 4 hr at 450°C and air cooled to room tem-

Jan 1, 1960

By P. A. Beck, A. H. Lutts

IN the classical picture of recrystallization the growth of strain-free grains at the expense of a strained and work hardened matrix is responsible for the softening of cold worked metals on annealing. It has been commonly assumed that the release of the stored energy of cold work, softening, and re-orientation take place simultaneously, as the high angle boundaries of the new recrystallized grains sweep over the cold worked matrix. However, recent evidence indicates',' that, at least in some cases, considerable or even complete soften- ing may take place essentially without reorientation (i.e., without the migration of ordinary high angle grain boundaries, or "recrystallization'') and the release of most of the stored energy of cold work may precede softening. These cases suggest that the property changes, taking place during the annealing of cold worked metals, may be associated with various distinct processes. The study of such situations is of considerable interest, since quantitative data are still scarce. In the present work, isothermal softening curves were determined for a heavily rolled aluminum single crystal, under such conditions that no "recrystallization" occurred until after complete softening. The hardness data were correlated with X-ray diffraction pinhole patterns in order to detect any reorientation that may occur and with measure-

Jan 1, 1955

By Monte J. Pool, Rudolph Speiser, George R. St. Pierre, William T. Ebihara

Standard free energies of formation of WO,, W O W20058 and WO3from oxygen and the lower oxide or tungsten have been determined in the tempel-ature range of 700° to 1220°C. A tentative W-O phase diagmm is presented based on the evidence that the oxide phases, "W18O49" and "W20058", are unstable at l~atm total pressure, below 585° and 485°C:, respectively. A HE need for a complete quantitative treatment of the phase equilibria of the W-O system has been establishedby metallurgists during the past few years. In an attempt to improve the endurance of tungsten exposed to oxidizing atmospheres at high temperatures, many research groups have studied the kinetics of tungsten oxidation. The reverse process, the reduction of the tungsten oxides to metal, has also been investigated to some extent. Regardless of the particular interest, metal to oxide or oxide to metal, a knowledge of the phase equilibria of the W-O system is required to properly interpret all of the kinetic observations. It should be possible to state the stable phases of the W-O system at any given values of the chemical potential of oxygen and the temperature.

Jan 1, 1962

By Morris A. Dodd

The nodulizing process described converts finely divided zinc calcine into a dense purified nodule. These zinc nodules are suitable for direct use in zinc reduction furnaces, especially the horizontal retort type, for the production of metal or American process zinc oxide furnaces for producing lead free zinc oxide. The basic reactions are carried out in a rotary kiln fired with fuel oil or natural gas. The combustion gases travel countercurrent to the flow of the zinc bearing material. Volatile impurities are carried out of the kiln with the combustion gases and a small portion of the finely divided feed material. The gases are cooled and the larger solid particles are separated from the stream before the resultant fume is collected in a conventional cloth filter baghouse. The fume collected can be further processed by conventional wet processes for the recovery of metallic values such as lead and cadmium. In order to nodulize the calcine properly it is elevated to a point of incipient fusion. The agglomerated material falling from the kiln is cooled and then sized by passing through a screening and crushing system consisting of a jaw crusher and a roll crusher in closed circuit with a vibrating screen.

Jan 1, 1970

By Keith Sutherland

AEROFLOAT 25 is a complex mixture of free cresylic acid with aryl substituted dithiophosphoric acids, sulphides, disulphides, etc. Its complete composition has not been published by the makers or patentees. It is prepared1 by the reaction between phosphorus pentasulphide and carefully selected cresylic acid. We have been informed that this acid contains no phenol and very little cresol, and that it is rich in the higher alkyl phenols, particularly the xylenols. The reaction between a phenol ROH and phosphorus pentasulphide may produce compounds of the following type:2 (i) RO S P Diaryldithiophosphoric acids RO SH (ii) R-SH Thiophenolic compounds (iii) R-S-R Diaryl sulphides (iv) R-S-S-R Diaryl disulphides (v) Substituted thianthren compounds Except for the simplest type, the thiophenols (ii), the boiling points of these compounds lie above 300° C. The amounts of the thianthren compounds formed from the five xylenols (if all these are present) will vary according to the position of the substituents. In an attempt to ascertain something of the nature of the reagent, fractional distillation under atmospheric pressure was undertaken. At the outset, hydrogen sulphide was freely evolved, and-particularly below 200° C.-the fractions had the strong odor characteristic of the

Jan 1, 1939

By C. H. Jr. Herty

IT Is well known that manganese will desulfurize molten iron through the formation of manganese sulfide, which, being only slightly soluble in the metal, rises to and enters the slag where it remains as such (mixer slag) or is converted partly or wholly to calcium sulfide (basic open¬hearth slag). The reaction by which manganese sulfide is formed is Mn + FeS = MnS + Fe. This reaction is generally considered to be reversible, although McCance1 states- that such is not the case. The experimental work was carried out to confirm the results of Rohl2 as to the reversibility of the reaction. Six trials are herein considered. In each 200 grams of electrolytic iron free from manganese and sulfur were melted in a pure zirconia crucible in a carbon resistance electric furnace. To the melted iron in runs 2, 3 and 4 metallic manganese and manganese sulfide were added to give 1, 2 and 4 per cent. manganese respectively, with 0.50 per cent. of sulfur in each. In runs 5, 6 and 7, metallic manganese andiron sulfide to give the same proportions of manganese and sulphur as in runs 2, 3 and 4, were added. The melts were held molten in the furnace for an hour and then cast into small ingots.

Jan 2, 1925

By John P. Ashby

Mine production blasting is a process of destruction of rock masses in order that ore may be extracted. Many open pit operations are faced with the apparently conflicting requirements of providing large quantities of fragmented rock for the processing plant and of minimizing the damage inflicted upon the surrounding pit slopes. A reasonable compromise between these two conflicting demands may often be found by means of simple engineering of production blasts. Many operations tend to rely too heavily upon traditional wall control techniques to alleviate a problem already created by the production blasts. Various production trends including use of larger blastholes and patterns have tended to aggravate the situation. These practices only serve to emphasize the need for engineered improvements. Central to blasting engineering is the process of systematic trial and evaluation. Changes to the blasting system should be made singly, starting with the simplest. This paper discusses simple changes involving drill pattern control, effective use of blastholes and explosives, adequate delaying including use of down-the-hole sequential techniques, effective utilization of free faces, and avoidance of "choked" situations. By directing explosive effort where it is needed, such changes generally result in a significant improvement of slope conditions and of production blasting cost and performance.

Jan 1, 1983

By W. C. Hittinger, J. McGlassan, J. W. Peterson

THIS paper describes the result of an investigation of the production of thin alloyed layers on a thicker substrate of pure germanium as one step in the manufacture of transistors.' The technique of alloying materials with semiconductors is a means of introducing small amounts of impurity elements in the alloyed regions of the crystal lattice of the semiconductor, the presence of which make possible the junction type transistor.2 Impurity elements are added which will produce regions having differing electrical resistivities and means of carrying current. Impurities are of two types: those which produce an excess of electrons (negative or n-type), and those which produce a deficiency of electrons (positive or p-type) in comparison to the pure semiconductor. The boundary between two such regions is designated a p-n junction. Elements in Group V of the periodic table, having five valence electrons, give rise to an excess of electrons when present substitutionally in the semiconductor lattice (usually germanium or silicon from Group IV). Similarly, elements in Group III create a deficiency of electrons. Germanium and silicon which are substantially free of impurities of either p or n-type are designated intrinsic (i-type) semiconductors. The usual junction ----trarnsistor has

Jan 1, 1958

By R. L. Smith, J. L. Rutherford

ALTHOUGH considerable effort has been devoted toward the determination of the mechanical properties of pure metals, it is extremely difficult to compare the results of such work. This is because of differences in method and type of test, grain size, heat treatment, and purity of material. There is very little information on the properties of most of the high melting point reactive metals with purities greater than 99.9 pct. Previous evidence concerning the tensile properties of unalloyed metals show that: body-centered-cubic metals are brittle at low temperatures; face-centered-cubic metals remain ductile; some hexagonal metals remain ductile, others become brittle. It may be that traces of impurities decrease the low temperature ductility of the body-centered-cubic lattice. This would suppose that a body-centered-cubic lattice free from impurities would exhibit nearly the same ductility as a face-centered-cubic structure. The present investigation has been an evaluation of the tensile properties of zone refined iron in order to determine whether higher purity material than that previously evaluated behaves differently. Experimental Procedure In this investigation, high purity iron was zone purified using the floating zone method.' The starting stock was obtained from two sources. The first,

Jan 1, 1958

By W. Evans, C. E. Ells

The agglomeration of hydrogen in pure aluminum and A1-Mg alloys has been studied through use of hydrogen introduced into the metal by cyclotron proton irradiation. Both the growth and dispersal of the agglomerates have been followed by metal-lographic techniques. During the cyclotron irradiation, agglomeration occurs at temperatures i 100°C for hydrogen concentrations as low as 1 ppm. On heating at elevated temperatures, 300°C to 600°C, intragranular agglomerates first coarsen and then disperse. The agglomerates formed at grain boundaries are much larger than the intragranular agglomerates; with hydrogen concentra- tions > 10 PPm, heating for 1 hr at 500°C results in extensive grain-boundary cracking. The hydrogen agglomerates have been shown to inhibit grain growth, but no inhibition of recrystallization has been observed. The ability of hydrogen to enter aluminum at a free surface, combined with its high-diffusion rate at elevated temperatures, accounts both for growth and dispersal of the agglomerates. Irradiations at elevated temperatures give results consistent with the explanation proposed for agglomerate behavior on post-irradiation heating. 1 HE formation of hydrogen-filled bubbles, or blisters. in aluminum and its alloys has been studied for over' thirty years. The work up to 1952 has been reviewed by Kostron' and since then Ransley and

Jan 1, 1963

By D. J. Jr. McAdam

RESULTS of investigation of corrosion-fatigue of metals at the U. S. Naval Engineering Experiment Station have been presented by the author in four papers. 1,2,3,4 In those papers references were given to the work of Haigh in 1917.5 The investigation at Annapolis included a variety of ferrous and non-ferrous alloys. The experiments showed that even slight corrosion simultaneous with fatigue may cause failure at stresses far below the ordinary endurance limit. The experiments also showed that, for most metals, severe stressless corrosion prior to fatigue is much less damaging than even slight corrosion simultaneous with fatigue. The term "corrosion-fatigue" was restricted to mean the simultaneous action of corrosion and fatigue. The combined effect of corrosion followed by fatigue was called "prior-corrosion fatigue." A stress-cycle graph representing corrosion-fatigue is a curve approaching a horizontal asymptote, the ordinate of which may be called a "corrosion-fatigue limit." To avoid confusion in later discussion, the term "endurance limit" will be restricted to mean the fatigue limit obtained by tests in air with specimens as free as possible from stress concentration and from corrosion. The endurance limit as thus obtained presumably represents an inherent property of the metal.

Jan 1, 1929

By D. J. McAdam

Results of investigation of corrosion-fatigue of metals at the U. S. Naval Engineering Experiment Station have been presented by the author in four papers.1, 2, 3, 4 In those papers references were given to the work of Haigh in 1917.5 The investigation at Annapolis included a variety of ferrous and non-ferrous alloys. The experiments showed that even slight corrosion simultaneous with fatigue may cause failure at stresses far below the ordinary endurance limit. The experiments also showed that, for most metals, severe stressless corrosion prior to fatigue is much less damaging than even slight corrosion simultaneous with fatigue. The term "corrosion-fatigue" was restricted to mean the simultaneous action of corrosion and fatigue. The combined effect of corrosion followed by fatigue was called "prior-corrosion fatigue." A stress-cycle graph representing corrosion-fatigue is a curve approaching a horizontal asymptote, the ordinate of which may be called a "corrosion-fatigue limit." To avoid confusion in later discussion, the term "endurance limit" will be restricted to mean the fatigue limit obtained by tests in air with specimens as free as possible from stress concentration and from corrosion. The cndursnce limit as thus obtained presumably represents an inherent property of the metal.

Jan 1, 1929

By D. J. McAdam

Results of investigation of corrosion-fatigue of metals at the U. S. Naval Engineering Experiment Station have been presented by the author in four papers.1, 2, 3, 4 In those papers references were given to the work of Haigh in 1917.5 The investigation at Annapolis included a variety of ferrous and non-ferrous alloys. The experiments showed that even slight corrosion simultaneous with fatigue may cause failure at stresses far below the ordinary endurance limit. The experiments also showed that, for most metals, severe stressless corrosion prior to fatigue is much less damaging than even slight corrosion simultaneous with fatigue. The term "corrosion-fatigue" was restricted to mean the simultaneous action of corrosion and fatigue. The combined effect of corrosion followed by fatigue was called "prior-corrosion fatigue." A stress-cycle graph representing corrosion-fatigue is a curve approaching a horizontal asymptote, the ordinate of which may be called a "corrosion-fatigue limit." To avoid confusion in later discussion, the term "endurance limit" will be restricted to mean the fatigue limit obtained by tests in air with specimens as free as possible from stress concentration and from corrosion. The cndursnce limit as thus obtained presumably represents an inherent property of the metal.

Jan 1, 1929

E. R. Buckley, Flat River, Mo. (communication to the Secretary*) :—Some statements in the paper of Mr. Keyes relative to the nature and formation of the Ozark lead- and zinc-deposits seen1 to me erroneous and misleading, and I respectfully present the following criticisms, placing Mr. Keyes's original statements in quotations. Referring to the Ozark dome: (p. 192.) "It is a region that has been repeatedly upraised and planed off, until in the middle portion the oldest known rocks only are exposed." Does he mean that the St. Francois mountains, which have always been considered as lying on the eastern flank of the Ozark dome, are the middle of the dome ? Or does he mean that the Cambrian rocks of the generally-accepted middle are the oldest known rocks ? Certainly not the latter, and if the former, his idea of the middle of the dome is not in accord with that of others who are familiar with the region. (p. 203.) "... the ore-deposits are definitely associated with, or localized by, geologic structures of some kind that produce in effect basins in which the underground waters are impounded, or their flow retarded." This statement does not appear to be altogether consistent with the facts, since the ore bodies of the Joplin district, as the rule, occur in those parts of the Mississippian formation which have a tendency to accel erate the flow of ground-water rather than retard it. I migh name the open, brecciated ground near Joplin, Webb City, and Oronogo as especially noteworthy illustrations. The ore-bodies, everywhere, occur in positions where there must have been a free and copious circulation of dilute lead- and zinc-solutions in the presence of reducing constituents. The inequalities in the distribution of the ore-deposits are

Jan 1, 1910

By Jerry Tien

Mine regulators are normally used for proper air distribution in underground mines. They are deliberately introduced resistance in the regulated airway, and by altering sizes, they can distribute specific air quantities to regulated splits and free splits (4, 5). The enactment of the Federal Coal Mine Health and Safety Act of 1969, the Federal Mine Safety and Health Amendments Act of 1977, and the regulations adopted by the Mining Enforcement and Safety Administration (now called the Mining Safety and Health ministration) prompted greater discussions of optimal mine regulator locations because of the Act's stringent ventilation requirements (2, 3). For example, by requiring the separation of the air used in the belt haulage entries from the intake and return airways, the regulations required the creation of a third type of airway---the neutral airway, as opposed to the intake and return airways, adding to the complexity of a mine's ventilation network. It is the intent of this report to show that panel regulators should be located in intake airways at the neck of a panel for a blowing fan system and in return airways at the neck of a panel for an exhausting fan system in order to achieve optimal air control. A computer simulation model is used to determine optimal mine regulator location.

Jan 1, 1983

By Frank C. Smith

THE following article covers the history of a metallurgical campaign, commenced in March, 1905, at the mines of the Socorro Gold Co., in the so-called desert region of Yuma county, Arizona. The results obtained were simply a function of necessity, as will be seen from the description of the local economic conditions and the character of the ores treated. The mines and mill of the Socorro Gold Co. are located near the small village of Harrisburg, about 60 miles from Congress Junction, Arizona, which, at the time this work was undertaken, was the nearest railroad station, and from which all supplies were brought by wagon through the desert, at a cost varying from $10 to $15 per ton in addition to the railroad freights. Wood, the only available fuel, cost $7 per cord. Water for all purposes was pumped to the plant from a well in the valley about 4 miles away. Under the Arizona law, a working-shift is 8 hr. Wages were $6 per day for foremen and mill-men, $4 per day for blacksmiths and engineers, $3.50 per day for miners, and $3 per day for shovelers and trammers. The ore consisted of quartz, in which, above the 250-ft. level, the iron-minerals were largely oxidized and some free gold was visible; below that level few traces of oxidation occurred, and pyrite constituted the principal mineralizer in the quartz, together with occasional pockets of galena and a few eccentric specks of covellite. The 20-stamp mill was equipped with plates for amalgamation, and three Standard tables for concentration. The tails from the tables were elevated by a centrifugal pump to a launder, by which they were conveyed to a 60-ton cyanide-mill for further treatment. The cyanide-mill was erected at so great a distance from the stamp-mill that a separate crew of workers and a separate power-plant were necessary. No arrangement had been made for the treatment of the concen-

Jan 1, 1907

By R. V. Whetsel, V. R. Garfias

For some time the writers have been compiling and analyzing statistics of consumption and production of petroleum, its products and related fuels, in order to arrive at a fairly accurate picture of the world-wide situation of the petroleum industry. In production, crude oil, natural gasoline, benzol and alcohol blended with motor fuel have been considered. In consumption not only refined products, but crude consumed as fuel, refinery losses, ships' bunkers and blended fuels have been taken into account to obtain a true balance between supply and demand. Statistics from practically every country and territory have been studied, and where actual figures were not available the estimates have been based on all the data available. The figures in Table 1 indicate that during the last five years the world's production has exceeded demand every year and that the aggregate difference is some 207,150,000 bbl. The supply in the United States exceeded consumption by 111,401,000 bbl. over the same five-year period and in 1931 and 1932 the demand exceeded supply, while outside the United States the excess of output over demand was 95,749,000 bbl. Table 2 combines the excess production in the United States with its favorable balance of exports over imports, showing that the United States has reduced its storage over the five years by about 136,-595,000 bbl., while in Table 3 it is shown that, including its excess of imports from the United States, the rest of the world has added 343,-745,000 bbl. to storage during the period in question, the greatest accumulation coming in 1934. Table 4 shows the world's consumption classified by countries according to the principal products. These tables also indicate that at the end of 1934 the statistical position of the petroleum industry outside the United States was decidedly unstable, a situation that probably will become more acute as a result of the added Iraq production; and that the present favorable statistical position of the industry in the United States, which is partly due to the excess of exports over imports, may be to some extent jeopardized by the unstable situation in the foreign market.

Jan 1, 1935

By C. R. Keyes

Discussion of the paper of C. R. Keyes, presented at the Chattanooga meeting, October, 190S, Bulletin No. 26, February, 1909, pp. 119 to 166. E. R. BUCKLEY, Flat River, Mo. (communication to the Secretary*) :-Some statements in the paper of Mr. Keyes relative to the nature and formation of the Ozark lead- and zinc-deposits seem to me erroneous and misleading, and I respectfully present the following criticisms, placing Mr. Keyes's original statements in quotations. Referring to the Ozark dome: (P. 127.) "It is a region that has been repeatedly upraised and planed off, until in the middle portion the oldest known' rocks only are exposed." Does he mean that the St. Francois mountains, which have always been considered as lying on the eastern flank of the Ozark dome, are the middle of the dome? Or does he mean that the Cambrian rocks of the generally-accepted middle are the oldest known rocks ? Certainly not the latter, and if the former, his idea of the middle of the dome is not in accord with that of others who are familiar with the region. (P. 138.) " . . . the ore-deposits are definitely associated with, or localized by, geologic structures of some kind that .produce in effect basins in which' the underground waters are impounded, or their flow retarded." This statement does not appear to be altogether consistent with the facts, since the ore- bodies of the Joplin district, as the rule, occur in those parts of the Mississippian formation which have a tendency to accel¬erate the flow of ground-water rather than retard it. I might name the open, breeciated ground near Joplin, Webb City, and Oronogo as especially noteworthy illustrations. The ore-bodies, everywhere, occur in positions where there must have been a free and copious circulation of dilute lead- and zinc-solutions in the presence of reducing constituents. The inequalities in the distribution of the ore-deposits are

Oct 1, 1909