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By Thomas Fraser, H. F. Yancey

Prior to the war just ended, Germany was the greatest coal producer in continental Europe. In 1943 the production of coal, bituminous and higher in rank, together with brown coal calculated to the equivalent amount of bituminous coal, is estimated to have been about 240 million metric tons, according to the War Department. Before the war production in Germany exceeded consumption. No other country in continental Europe except Poland had a large surplus. However, England's surplus was the largest in Europe as a whole. Before World War II the Ruhr Basin normally supplied about 70 pet of the total production of high-rank coal, the Saar and Aachen about 6 pet each, Upper Silesia about 14 pet, and Silesia and Saxony the remainder. Nearly one third of the brown coal was produced in the Rhineland, a little less than one half in central Germany nest of the Elbe River, and about one fourth east of the Elbe. Bituminous coal and brown coal together constituted by far the most important energy resources of the old German Reich. Bituminous coal furnished nearly 70 pet of the total energy requirement, brown coal supplied about 25 pet, and water power, wood, petroleum and alcohol together aggregated only 7 pet. Because it was the most important single mineral resource of Germany, an excess of coal enabled the Reich to import nearly all the other mineral products that she lacked, such as iron ore from Lorraine. The area adjacent to the coal fields was supplied with gas from an interconnected grid. Similar electric grids are based on brown coal with the power stations at the mines. Coal tar provided the foundation for the development of the extensive German chemical industries as exemplified by the I. G. Farbenindustrie. For almost a century, German scientists have been adequately supported both by the State and by industry in studying improved methods of utilizing coal. In Germany the mineral rights were reserved by the State and ordered eatraction of coal was enforced. Each lease comprised a relatively extensive area. which accounts for the generally large size of the mines and mining companies In 1938 there were 160 mines in the Ruhr, with a total output of 125 million tons but 90 pet of the production was controlled by 20 companies. By far the largest single coal-mining company in Germany was the Gelsen-kirchener Bergwerke A. G., which produced nearly 27 million tons in the Ruhr in 1937. Second was Saargruben A. G. a State-owned company operating in the Saar, which produced 'lore than '3 million tons. Third was Bergwerksgesellschaft Hibernia A. G., with 10 million tons, also in the Ruhr. Briquettes are made from both bitumillous coal and brown coal, but in 1938 some 44 million toils of brown-coal bri-

Jan 1, 1947

By Thomas Fraser, H. F. Yancey

Prior to the war just ended, Germany was the greatest coal producer in continental Europe. In 1943 the production of coal, bituminous and higher in rank, together with brown coal calculated to the equivalent amount of bituminous coal, is estimated to have been about 240 million metric tons, according to the War Department. Before the war production in Germany exceeded consumption. No other country in continental Europe except Poland had a large surplus. However, England's surplus was the largest in Europe as a whole. Before World War II the Ruhr Basin normally supplied about 70 pet of the total production of high-rank coal, the Saar and Aachen about 6 pet each, Upper Silesia about 14 pet, and Silesia and Saxony the remainder. Nearly one third of the brown coal was produced in the Rhineland, a little less than one half in central Germany nest of the Elbe River, and about one fourth east of the Elbe. Bituminous coal and brown coal together constituted by far the most important energy resources of the old German Reich. Bituminous coal furnished nearly 70 pet of the total energy requirement, brown coal supplied about 25 pet, and water power, wood, petroleum and alcohol together aggregated only 7 pet. Because it was the most important single mineral resource of Germany, an excess of coal enabled the Reich to import nearly all the other mineral products that she lacked, such as iron ore from Lorraine. The area adjacent to the coal fields was supplied with gas from an interconnected grid. Similar electric grids are based on brown coal with the power stations at the mines. Coal tar provided the foundation for the development of the extensive German chemical industries as exemplified by the I. G. Farbenindustrie. For almost a century, German scientists have been adequately supported both by the State and by industry in studying improved methods of utilizing coal. In Germany the mineral rights were reserved by the State and ordered eatraction of coal was enforced. Each lease comprised a relatively extensive area. which accounts for the generally large size of the mines and mining companies In 1938 there were 160 mines in the Ruhr, with a total output of 125 million tons but 90 pet of the production was controlled by 20 companies. By far the largest single coal-mining company in Germany was the Gelsen-kirchener Bergwerke A. G., which produced nearly 27 million tons in the Ruhr in 1937. Second was Saargruben A. G. a State-owned company operating in the Saar, which produced 'lore than '3 million tons. Third was Bergwerksgesellschaft Hibernia A. G., with 10 million tons, also in the Ruhr. Briquettes are made from both bitumillous coal and brown coal, but in 1938 some 44 million toils of brown-coal bri-

Jan 1, 1947

By Sandford S. Cole, John S. Breitenstein

The recovery of over 80 pct of the vanadium values in titaniferous magnetite from Maclntyre Development,Tahawus, N. Y., was accomplished by an oxidizing roast with Na2O3-NaCI addition. Process description is given for leaching of roasted ore and precipitation of V2O5 and Cr2O8 from leach liquor. THE exploration and development of the Mac-Intyre orebody at Tahawus, N. Y., by the National Lead Co. provided a source of vanadium. Analyses of various composite sections of the drill cores of the MacIntyre orebody were made to establish whether or not the vanadium was constant throughout. Ten drill cores were sampled as 50 ft sections, crushed, and a portion magnetically concentrated. The head and concentrate were analyzed for total iron and vanadium. The results on the concentrates indicated that the vanadium is associated with the magnetite and maintains a close ratio to the iron content. The nominal ratio of 1:25:140 of V: TiO2:Fe was found to exist in the concentrates. Typical value for the vanadium in the magnetite both from laboratory concentration and mill production is 0.4 pct. The recovery of vanadium from the magnetite was investigated in 1942 to 1943. The research program encompassed both laboratory and pilot-plant work on sufficient scale to provide adequate data to establish the feasibility of a full scale plant. The recovery of vanadium from various ores has been reported in the literature and has been the subject of many patents. The literature dealing with recovery from titaniferous ore by roasting is quite limited. Roasting with alkaline sodium chloride, sodium chloride or alkaline earth chlorides, and sodium acid sulphate have been claimed in various processes as effective means.1-8 The reduction of the ore, followed by acid leaching, was another method proposed.'-' "he use of various pyrometallurgical processes for recovery of vanadium in the metal or in the slag has also been extensively investigated, but the results had little application to the problem."-" The separation of vanadium values from subsequent leach liquors and vanadium-bearing solution has been the subject of a considerable number of papers and patents. The most practical is by hydrolysis at a pH of 2 to 3 by acidifying a slightly alkaline solution. Data on solubility of V²O5 and V2O4 in water and in dilute sulphuric acid indicated a solubility of 10 g per liter in water.'" Laboratory Results Magnetite Analysis: Adequate stock of magnetite was provided so that the laboratory and pilot-plant operation was on ore representative of the mill production. The ore was analyzed chemically and examined by petrographic methods to ascertain whether the vanadium was present in combined state or as an interstitial component between grain boundaries. No evidence was obtained which would indicate that the vanadium was in a free state as coulsonite.15 The analysis of the ore was as follows: Fe²O³, 47.4 pct; FeO, 29.1; TiO,, 10.1; V, 0.40; and Cr, 0.2. The screen analysis of the ore on the as-received basis was: -20 +30 mesh, 28.8 pct; —30 +40, 18.9; -40 +50, 9.7; -50 +60, 15.1; -60 4-100, 5.9; -100 + 200, 11.2; -200 +325, 3.7; and -325, 7.2. Roasting Conditions: The prior practice indicated that a chloridizing roast with or without an alkaline salt had been effective on other titaniferous magnetites. On this basis roasts with additions of sodium chloride, sodium carbonate and mixtures thereof were investigated varying the roasting temperature between 800" and 1100°C. Since the ore had shown no segregation or concentration of vanadium, the influence of particle size on the freeing of vanadium by the reagents during roasting was determined. The initial work was on silica trays in an electric resistance furnace with occasional rabbling of the charge. Subsequently, the roasting was carried out in a small Herreshoff furnace to establish the influence of products of combustion on the recovery of the vanadium. The laboratory tests showed that this ore required an alkaline chloridizing roast, in conjunction with a reduction in particle size to less than 200 mesh. When roasted in air at 900 °C with 5 pct NaCl and 10 pct Na2CO³, over 80 pct recovery of the vanadium was attained as a water-soluble salt. The presence of alkaline earth elements gave detrimental effects and care had to be exercised to avoid any contamination of the ore or roast product by such materials. The solubilization of vanadium under the various conditions is given in a series of curves in Figs. 1 to

Jan 1, 1952

By J. E. Metcalfe

Proceedings of the Fourth Empire Mining and Metallurgical Congress, Great Britain 1949. Part II published at the Offices of the Congress in London, England, 1139 pp. The price of these proceedings is £ 2. The parts may be purchased separately at a cost of £ 1 each.-Part I of this book covers a report of the organizing committee, the inaugural meeting and presidential address, banquet at Guildhall, welcome by Sir Richard Livingstone at Oxford. and final session. Technical session and papers are also covered in Part I. Part II covers such topics as coal, present-day trends in mineral dressing and metallurgy. Mining Engineer's Survey Manual. By J. E. Metcalfe. Published for "Mine & Quarry Engineering" by Electrical Press, London, 1951. 341 pp., illus., charts, diagrs., tables, 8 ¾ x 5 1/ in., cloth, 30s., available from Percival Marshall & Co., Ltd., London, and British Book Centre, 122 East 55th St., New York 22, N. Y. Beginning with a brief treatment of surveying fundamentals and a discussion of the correlation of surface and underground surveys, this practical manual continues with descriptions of surveying practice both above and below ground including stopes, inclined shafts; etc. Space is devoted to sampling and valuation, geological considerations, and descriptions of modern surveying instruments. The organization of survey operations is covered in the last chapter.

Jan 1, 1952

By Betty J. Laswell, Gerald W. Laswell

Rotary drilling in modern open-pit mining is usually considered the lead phase which not only establishes the production rates but frequently limits them. From this viewpoint alone, the drilling phase must be maximized. The drill phase is the step that permits all the other operational phases to function within their design limits. This means that, in most cases, the drill is literally run to destruction to ensure that the shovel will be able to smoothly and consistently load a manageably size muck, the haul trucks can carry a balanced load without having a boulder dropped through the bed, and the crusher can devour constant rock size.

Jan 8, 1978

By AIME AIME

AMONG the industrial motion pic¬tures released in the last year of possible interest to people in the mining industry are the following: "A New World Through Chemistry," made by the public relations department of E. I. du Pont de Nemours & Co., Wilmington, Del. This film, which is in sound and color, interprets in twenty minutes of narration and ingenious photography many of chemistry's newest developments. It may be borrowed either in 16-mm. size on an 800-ft. reel, or 35-mm. size on a 2000¬ft. reel, the only charge being the cost of returning the film. Douglas D. Rothacker, 729 Seventh Ave., New York City, is prepared to loan free of charge except for transportation each way several films prepared in the plants of the International Nickel Co., 16 mm. with sound. These include: "Nickel High Lights," 35 minutes; "Nickel Mining," 18 minutes; "Nickel Smelting," 18 minutes; "Nickel Refining," 9 minutes; and "Copper Refining," 6 minutes.

Jan 1, 1941

By Albert D. Brokaw

The accompanying charts are presented to extend and improve a chart published under the title "A Chart to Provide Approximate Correction for Temperature and Deviation from Boyle's Law."' The applicability of this earlier chart was limited by the fact that it was based on the work of Burke and Keyes² and Kvalnes and Gaddy3 whose experiments were conducted with pure methane, the adjustments suggested for natural gases of higher specific gravity were unsatisfactory except within limited ranges of temperatures and pressures, and precise interpolation was difficult. The extensive work of G. G. Brown, D. L. Katz and their associates on the heavier natural gases has provided better bases for the needed corrections, and the present charts. which are based largely on their work, are intended to simplify the computations involved. The design of the charts has been changed by plotting temperatures as a function of pressure and correction factor, on a semilogarithmic or "ratio" grid, which gives fairly even spacing of the graphs and simplifies interpolation. Charts have been prepared for natural gas with specific gravities of .60, .65, .70, .75 and .80. The standard computation for use in estimating the quantity of gas in a reservoir may be expressed as follows: _ PA X 520 X VR ZT where: Q is the volume of gas at 60°F and one atmosphere pressure PA is the absolute formation pressure in atmospheres

Jan 1, 1949

By Albert D. Brokaw

The accompanying charts are presented to extend and improve a chart published under the title "A Chart to Provide Approximate Correction for Temperature and Deviation from Boyle's Law."' The applicability of this earlier chart was limited by the fact that it was based on the work of Burke and Keyes² and Kvalnes and Gaddy3 whose experiments were conducted with pure methane, the adjustments suggested for natural gases of higher specific gravity were unsatisfactory except within limited ranges of temperatures and pressures, and precise interpolation was difficult. The extensive work of G. G. Brown, D. L. Katz and their associates on the heavier natural gases has provided better bases for the needed corrections, and the present charts. which are based largely on their work, are intended to simplify the computations involved. The design of the charts has been changed by plotting temperatures as a function of pressure and correction factor, on a semilogarithmic or "ratio" grid, which gives fairly even spacing of the graphs and simplifies interpolation. Charts have been prepared for natural gas with specific gravities of .60, .65, .70, .75 and .80. The standard computation for use in estimating the quantity of gas in a reservoir may be expressed as follows: _ PA X 520 X VR ZT where: Q is the volume of gas at 60°F and one atmosphere pressure PA is the absolute formation pressure in atmospheres

Jan 1, 1949

Cyanidation and Concentration of Gold and Silver Ores. By J. V. N. Dorr and Francis L. Bosqui. Second edition, completely revised. Mc-Graw-Hill Book Co., New York. $8.50.-First issued 13 years ago, this book has become a milestone in the literature of mining and metallurgy. Mr. Dorr, with the assistance of F. L. Bosqui, has completely revised the book. Its comprehensive picture of ore dressing and hydrometallurgical methods are of importance to mining engineers and operators throughout the entire field. Operating data and methods, flowsheets, testing procedures, and many miscellaneous methods of extracting bullion are given. The book is divided into two sections, the first discussing principal unit processes involved in gold and silver recovery, and the second describing with flow diagrams a number of typical treatment plants selected from the more important gold and silver mining areas in various parts of the world. International Conference on Coal Preparation in Paris. English Language edition of transactions.-The transactions of the recent conference in Paris will be presented in the form of 6 issues of the revue de l'Industrie Minerale, and may be purchased for 3000 francs per set. About 60 papers were presented at the meeting, covering a wide range of interesting subjects. Ad- dress subscriptions to: Secretariat de la Societe de l'Industrie Minerale, 19 rue du Grand-Moulin, Saint-Etienne (Loire) France.

Jan 1, 1951

By C. P. Proctor

WESTERN Pennsylvania, eastern Ohio, and Illinois are carrying out experiments wherein much more slate and other impurities are loaded with the coal in the mine and hauled to the surface preparation plant for removal. In general everything is sent to the cleaning plant although there may be some gobbing in the mine. No conclusions have been announced as to the effect of such a mining system on clean coal costs. Such factors as ability of the surface plant to handle the impurities, land and facilities for disposing of the impurities, and the transportation facilities underground should be considered.

Jan 1, 1942

By Carl F. Floe, John Chipman

THE system molten copper-oxygen-sulphur is of interest from both the practical and theoretical standpoints; practically, because oxygen and sulphur play an important role in the commercial production of copper, and theoretically because it offers a chance to study the reaction between an oxide gas, SO2, and a molten metal. Reactions of this type, such as that between CO or CO2 and molten iron, are important in many metallurgical operations. Again, the determination of any gas-metal equilibrium is of theoretical interest and value insofar as it contributes to the general development of the laws for solution of gases in metals. This problem is being given an increasing amount of attention in modern metallurgy. This paper is the first of a series and presents the results of a determination of the solubility of sulphur dioxide in molten copper at temperatures from 1100° to 1500°C., and pressures from about 20 mm. of mercury to somewhat above atmospheric. REVIEW OF PREVIOUS WORK The solubility of gases in most liquids has been found to obey Henry's law, which states that for a fixed temperature the amount of gas dissolved is directly proportional to the pressure. However this law does not hold for liquid metals. Instead, it appears that for many gases, particularly the simple diatomic ones such as 02, N2 and H2, the amount dissolved in liquid metals is directly proportional to the square root of the pressure. This is known as Sieverts' law. It may be recognized as a special case of Henry's law, which applies when the solute gas is dissociated into atoms or when it reacts with the solvent metal to form solute molecules containing single atoms of the gaseous elements, as, for example: [(MG) l 2M +G2 = 2MG K = Ma X Pa, [I]] which, if the solubility is not too high and the concentration of metal therefore nearly constant, can be simplified to: [MG = Kl Pa,[2]] Following the same reasoning, it would be expected that the solubility of SO2 in copper would be proportional to the cube root of the pressure, the reaction being as follows: [6Cu + SO2 = Cu2S + 2Cu20[3] K _ Cu2S X (Cu20)2 (Cu)6(Pso2)[4]] or, neglecting the change in metal concentration and considering that the concentrations of sulphur and oxygen are both proportional to the volume V of gas absorbed: [8 =KI = Pte, or VSO2= K2 '~/PeO, [S]]

Jan 1, 1941

By W. L. Fink, M. S. Hunter, R. H. Brown

Early workers attempted to study the structure of alloys by measurement of equilibrium electrode potentials in aqueous solutions containing ions of the metals from which the alloy was made.' The method was subject to such limitations (e.g., the difficulty in attaining electrochemical equilibrium at low temperatures) that it has not been widely used by metallurgists. Recently, Seltz and co-workers have introduced a greatly improved method for studying alloys by measurement of equilibrium electrode potentials in molten salts.2"4 The mathematical treatment is the same, of course, as for equilibrium potentials of amalgams in aqueous solutions.5 This method will probably find extensive use, since it makes possible not only the determination of phase fields of equilibrium diagrams but also the determination of certain thermodynamic quantities which can be used advantageously in metallurgical calculations. However, the method presents difficulties. With many metallic and alloy electrodes, reversibility is not readily obtainable. Also, the difficulty of obtaining suitable material from which to make the cells is increased as the temperature is increased. Moreover, the necessity of carrying out measurements in a vacuum requires additional apparatus and introduces considerable difficulty, especially at the higher temperatures. Apparently, no consideration has been given heretofore to the metallurgical use of irreversible electrode potentials that exist when a specimen is immersed in a suitable aqueous solution at room temperature. The apparatus and the method required for such measurements are very simple, and if the results of such measurements could be demonstrated to be reproducible they might be very valuable in studying the structure of alloys. The method would not have the scope of that developed by Seltz and his co-workers because no thermodynamic quantities could be calculated from the data. However, the utility and the simplicity of the method might warrant extensive use for the determination of phase fields and similar applications. Theory of Irreversible Potentials A brief review of the theory of irreversible potentials will be given before showing how to interpret the potential readings in terms of alloy structure. It is known that heterogeneity of a metal surface in an electrolyte will produce points of different potentials, with the result that current flows between these points and electrochemical reactions occur. The points at which oxidation reactions are localized are known as anodes, and those at which reduction reactions are localized are known as cathodes.6, 7, 8 For the benefit of those who are not familiar with the terms anode and cathode as applied to a primary cell, the potential difference between anode and cathode of such a cell can be measured when

Jan 1, 1941

By M. S. Hunter, W. L. Fink, R. H. Brown

Early workers attempted to study the structure of alloys by measurement of equilibrium electrode potentials in aqueous solutions containing ions of the metals from which the alloy was made.' The method was subject to such limitations (e.g., the difficulty in attaining electrochemical equilibrium at low temperatures) that it has not been widely used by metallurgists. Recently, Seltz and co-workers have introduced a greatly improved method for studying alloys by measurement of equilibrium electrode potentials in molten salts.2"4 The mathematical treatment is the same, of course, as for equilibrium potentials of amalgams in aqueous solutions.5 This method will probably find extensive use, since it makes possible not only the determination of phase fields of equilibrium diagrams but also the determination of certain thermodynamic quantities which can be used advantageously in metallurgical calculations. However, the method presents difficulties. With many metallic and alloy electrodes, reversibility is not readily obtainable. Also, the difficulty of obtaining suitable material from which to make the cells is increased as the temperature is increased. Moreover, the necessity of carrying out measurements in a vacuum requires additional apparatus and introduces considerable difficulty, especially at the higher temperatures. Apparently, no consideration has been given heretofore to the metallurgical use of irreversible electrode potentials that exist when a specimen is immersed in a suitable aqueous solution at room temperature. The apparatus and the method required for such measurements are very simple, and if the results of such measurements could be demonstrated to be reproducible they might be very valuable in studying the structure of alloys. The method would not have the scope of that developed by Seltz and his co-workers because no thermodynamic quantities could be calculated from the data. However, the utility and the simplicity of the method might warrant extensive use for the determination of phase fields and similar applications. Theory of Irreversible Potentials A brief review of the theory of irreversible potentials will be given before showing how to interpret the potential readings in terms of alloy structure. It is known that heterogeneity of a metal surface in an electrolyte will produce points of different potentials, with the result that current flows between these points and electrochemical reactions occur. The points at which oxidation reactions are localized are known as anodes, and those at which reduction reactions are localized are known as cathodes.6, 7, 8 For the benefit of those who are not familiar with the terms anode and cathode as applied to a primary cell, the potential difference between anode and cathode of such a cell can be measured when

Jan 1, 1941

By B. C. Allen

The solubility of chromium in liquid silver and that of molybdenum and tungsten in liquid tin have been determined by equilibrating Ike Liquid in a crucible of the solule metal. Generally the weight of solute in solulion was delermined both chemically and from crucible weight losses. The resulting weight percent solubilily of chromium in silver as a function of absolule temperature T is given by log w = -6660/T + 4.02 in the range 960° to 1445°C, and that of molybdenlttrl in tin by log w = —5050/T + 1. 79 in the range 1200° to 2200°C. The values appear unaffected by minor changes in solute composition. Calculations aye made of the parlial molar heal and excess entropy of mixing. The estimated solubility of tungsten in tin is 0.001 pct at 2000°C. Evidence is presented that molybdenwm dissolves in tin without compound for mation and that tungsten and tin form W10Sn. RECENT developments in coatings, heat transfer, and brazing require a knowledge of equilibrium solubilities in a variety of systems at elevated temperatures. Of particular interest are solid-liquid interactions in metal systems involving dilute solutions. This investigation was undertaken since little is known about the phase relations or solubility of chromium in liquid silver or of molybdenum and tungsten in liquid tin.1,2 EXPERIMENTAL WORK As indicated in Table I, high-purity metals or those of known impurity levels were used. Crucibles were machined from chromium, molybdenum, and tungsten bar stock 1.3 cm diam and 2.2 cm long. Chromium rod was prepared by arc melting and extruding iodide process crystals.3 The five chromium impurity alloys were in the form of 0.6-cm-diam swaged rod. A Cr-0.06N* alloy was prepared by exposure to NH3 at 1150°C in a closed quartz capsule for 24 hr. Because significant nitrogen was lost during annealing in argon at 1600°C,4 the estimated level was 0.01 pct N. Chromium and Mo,W crucibles were outgassed at 1200" and 1600°C, respectively, at 3 X 10-5 mm. The solvent was placed In crucibles of the solute metal- 6 g Ag in chromium, 0.4 g Ag in the five chromium impurity alloys, and 4 g Sn in Mo,W crucibles. The silver and tin series were outgassed at 900" and 110O°C, respectively, and held at the desired solution temperature in a tantalum resistance furnace under 1.05 atm 99.995 pct Ar. An equilibration time of 0.5 to 1 hr was chosen since 0.3-, I-, and 4-hr anneals at 1235°C for Cr-Ag yielded similar results. Temperatures were measured optically to +10°C under essentially black body conditions which were checked against the melting point of silver. The Cr-Ag and Mo-Sn,W-Sn series were respectively equilibrated at 990° to 1400°C and 1200" to 2000°C. Vaporization losses were generally held to <1 pct by the argon. In the 1800" and 2000°C anneals for 0.5 hr, the crucibles were placed in tightly sealed tantalum cans which kept tin losses to <5 pct. After the anneals, the specimens were furnace-cooled. One anneal was made on small Mo-0.02 C, Mo-0.5Ti-0.lZr, and tungsten crucibles containing tin at 2200°C. The metals were sealed in an electron-beam-welded tantalum can of minimum volume. After the anneal, tin was still present in each crucible, none of which was severely attacked. After equilibration, the saturated solvent metal was selectively removed from the crucible by acid leaching. Weight losses sustained by the crucibles were determined from the initial weight minus the final blank-corrected weight after acid leaching. Chemical analyses were performed on some of the samples. Hot 1:l HNO3-H2O removed silver from chromium with the blank running <0.1 mg or <0.002 pct on measured solubility. Tin was removed from molybdenum and tungsten by hot concentrated HC1 with the respective blanks amounting to -0.004 and -0.0004 pct in the presence of tin. The insoluble residues were weighed and checked for composition. The leaching solutions contained traces of the solute metals which were analyzed by colorimetric methods, Diphenyl Carbazide for chromium, Thiocyanate for molybdenum, and Dithiol for tungsten. The total of the two percentages found from the residue and leaching solution minus the blank gave the desired solubility values. On the basis of annealing empty molybdenum and tungsten crucibles, weight losses due to MoO3 or WO3 volatilization were found to be generally 10.4 mg and affect measured solubilities by <0.01pct. RESULTS AND DISCUSSION Chromium-Silver . Since no intermediate compounds are reported to form in the Cr-An system,&apos; crucible weight losses and chemical analysis of the entire melt should provide reliable measures of the chromium in solution. Values obtained by the two methods are in agreement as shown by the results for unalloyed chromium in Table II and plotted in Fig. 1. Furthermore, the results are consistent with those previously determined by melting equilibrated silver out of the crucible and analyzing calorimetrically for chromium.&apos; On the basis of limited thermal analysis data, the solubility of chromium in silver has been quoted as 8 pct at the monotectic temperature of -1445°C.1 This investigation indicates an extrapolated solubility of 1.38 pct which is believed to be more reliable. At the eu-

Jan 1, 1968

By Rees D. Rawlings, C. W. A. Newey

The aging characteristics of an Fe-11 at. pct Mo alloy have been studied by means of light metallography together with density, Young&apos;s modulus, and hardness measurements. The results were consistent with the precipitation of a single intermetallic compound during aging; overaging was slow relative to that in other iron-based binary alloys. The solution treatment temperature had a small effect on the rate of hardening whereas deformation prior to aging had a marked effect on both the rate of hardening and the peak hardness. The density data indicate that the compound precipitated is Fe3MO2 and not the Laves phase Fe2Mo. Analysis of the modulus and density results gave values for the time exponent for precipitate growth of approximately 1.0 and 1.5 for the alloy aged with and without prior deformation, respectively. DETAILED studies of precipitation hardening in bcc matrices have been confined largely to the effects of carbides and nitrides. In view of this and the growing technological interest in intermetallic compound strengthening, e.g., in maraging steels, a study of precipitation in iron-based alloys with a low interstitial content has been undertaken. This paper is concerned with the aging behavior of an Fe-11 at. pct Mo alloy; the mechanical behavior of the alloy will be reported later. The early work of sykes on Fe-Mo alloys showed that precipitation of the intermetallic compound was accompanied by an increase in hardness and a decrease in volume of the material. More recent surveys of the strengthening associated with precipitation have been made3-5 and, in particular, Elsen and wassermann4 showed that deformation prior to aging increased the rate of hardening. These latter workers also followed the precipitation process by means of dilatometry, electrical resistivity, and lattice parameter measurements. Their results confirmed that there is a decrease in volume on aging. Except for the work of Hornbogen on an Fe-20 at. pct Mo alloy, neither clustering nor the precipitation of a nonequilibrium phase has been observed in Fe-Mo alloys. Studies of alloys of lower molybdenum content475 indicate that the equilibrium intermetallic compound is precipitated during aging. However, there is some doubt concerning the nature of the equilibrium precipitate phase. According to the phase diagram constructed by Hansen,8 the phase should be precipitated. This phase has a rhombohedra1 crystal structure which is characterized by the formula Fe706,&apos; although the composition of the molybdenum-rich boundary corresponds approximately to Fe3Mo2. The version of the diagram proposed by Sinha, Buckley, and Hume-Rother indicates that the A phase, a Laves phase Fe2Mo, should be precipitated. Their observation of a Laves phase supports the earlier findings of Bechtoldt and Vacher,13 although, in a recent study of the system by means of diffusion couples, Rawlings and Newey did not detect the phase. The work presented here describes the effect of solution-treatment temperature, aging temperature, and prior deformation on the aging characteristics of the alloy as revealed by light metallography together with hardness, density, and Young&apos;s modulus measurements. In addition the density data are used in an attempt to determine the compound precipitated during aging. EXPERIMENTAL PROCEDURE A 29-kg ingot of the alloy was cast at R.A.R.D.E., Fort Halstead, from deoxidized, Japanese electrolytic iron and sintered molybdenum. The ingot was homogenized for 6 hr at 1473°K and then worked, with intermediate anneals, into 6- and 16-mm-diam rods and 6-mm plate. Chemical analysis of the alloy gave, wt pct: Mo, 17.5 (11 at. pct); C, 0.003; Si, 0.002; S, 0.005; P, <0.002; and02, 0.0098. Solution treatments were carried out under a dynamic argon atmosphere in a vertical, "crusilite" element, furnace which had a facility for rapid quenching into iced water. Except for the study of the effect of solution treatment temperature, all specimens were solution-treated at 1573" * 2°K for 1 hr. Salt baths were used for the aging treatments. Specimens for hardness, density, and Young&apos;s modulus measurements were produced, after heat treatment, from the stock rod or bar using a precision silicon carbide slitting wheel. As described later, the quenching treatment produced local plastic strain in the stock material; consequently, care was taken to ensure that the specimens were not prepared from these regions. Those specimens used in the studies of the effects of prior deformation on the aging behavior were strained in compression in a Denison universal testing machine. Specimens for light metallographic observations were mechanically polished on successively finer grades of diamond paste down to and then etched in either alcoholic ferric chloride or in a 2 pct nital solution. Vickers diamond pyramid hardness data were obtained using a 30-kg load. At least five impressions were averaged for each determination. Density measurements were made using a displacement technique in which each specimen was weighed in air and in dibromoethane at 296°K. The specimens were cylindrical and weighed 3 to 4 g; all weighings were made on a balance reading to 1 x 10"5 g. For each specimen the mean value of five weighings was used to calculate the density. The density of the dibromoethane was determined using the displacement procedure and a standard nickel specimen. The error in an absolute density value was estimated to be HI.01 pct. To obtain the density as a function of aging time a single specimen was used and the density meas-

Jan 1, 1969

By Ernest F. Burchard

PAGE. I. Introduction,........... 75 II. Outline of the Geology......... 76 1. Stratigraphy............ 76 A. Clinton Formation........ 77 2. Structure...........82 3. The Ore..........85 A. Character............ 85 B. Geographic Distribution....88 III. Local Descriptions........... 88 1. Birmingham District.......... 88 A. Topography and Its Relation to Industrial Development... 88 H. Distribution and Structure of Formations.... 89 C. Divisions of the Birmingham District. 95 Division A (Description of the Ore-Beds), . 95 Division B.........105 Division C.......... 106 Division D,..107 Division E,...........108 Division F........ 111 Division C.......... 112 D. Mining .Development.... 113 2. Northeast Alabama........114 IV. Possible Origin oF the Ore......... 119 V. Relation of Origin to Quality and Extent of Ore... 122 VI. Estimates of Ore-Reserves,......... 125 1. Method of Making Estimates......... 125 2. Data and Results....126 VII. Production and Consumption oF IRon-ORe,.... 132 I. Introduction. Brief and interrupted studies of the Alabama Clinton iron-ores have been made within the last four years by members of the IT. S. Geological Survey. Reports on the progress of this

Jan 1, 1910

BECAUSE of the impetus given to placer mining since the price of gold was advanced to $35, several types of small dredges have made their appearance, especially in the Lincoln and Oroville areas of California. Some of these are known as "doodle bugs," and have been given considerable publicity, though many believe their performance has been overrated and that complete costs of construction and operation, if known would not put them in so favorable a light. Fig. 1 is a doodle bug owned by E. M. Clark and operated near Lincoln, Calif. It is understood that it was abandoned because of inability to handle deep ground. A similar machine that has been operated-profitably by Comstock Placers is shown in Fig. 2.

Jan 1, 1938

By I. W. Alcorn

THE cost of drilling in the past few years of proration and ever decreasing allowables has received increasing thought and study. It seems to parallel the strides made with respect to pumping problems in 1932 and 1933. Low profit margins stimulate the search for economies. Any discussion of slim-hole drilling involves a multitude of abstract values, and the problem can be attacked only by a study of records and rational thinking. In a measure, traditional methods must be studied with a questioning attitude. The words "slim hole" may be somewhat misleading, as the term is entirely relative. For that reason I wish to define it as used in this discussion. On the Gulf Coast, I would define a normal hole as one in which 10 3/4-in. surface casing has been set and below which a 9 7/8-in. hole is dug. With this as a datum, holes of larger diameter below surface would be called "large holes," with 12 1/4 in. as the "extra large" class and holes of smaller diameter classed in the slim-hole range, 6 1/4 in. representing about the minimum size. The optimum size has not been definitely determined, but the preference is for a program that would call for setting 8 5/8-in. surface casing and digging a 7 3/4-in. hole. Different sections of the country might very properly deviate from this practice because of differences in depth, formations, regulations, or other factors. This paper will be confined to a discussion of the drilling of exploratory wells, as the drilling of this class of wells is quite a different problem from that of drilling a proven field, although many of the same considerations apply in both cases, as will be apparent. Although for many years shallow slim-hole and core-test holes of small diameter had been dug, it was not, I believe, until the fall of 1937 that serious consideration was given to its application in drilling wells 7000 ft., 8000 ft. and 9000 ft. deep on the Gulf Coast. This does not mean that nearly all such wells drilled on the Gulf Coast now are of the slim-hole variety, but only that efforts have been aimed in that direction with very encouraging results and there has been a very definite trend to reduce the size of holes, a trend that probably will continue. As to exploration policy, there appear to be two distinct and opposite views. The one usually followed in the past was more or less designed to "shoot the works" on one well. Generally on the Gulf Coast, the depth at which production might be obtained is limited by the drilling equipment and economics. With this thought in mind, wildcat wells are often planned with the idea of carrying the depth to 10,000 ft., or even 15,000 ft. All of the possible hazards are anticipated and the general drilling and casing programs are so predicated. Such wells contemplate the drilling of large-diameter holes; the setting of at least one protective string of casing and an extensive coring policy, all of which finally adds up to an expensive well. As opposed to this general policy is the slim hole. This, on the Gulf Coast, recognizes that new discoveries represent gam-

Jan 1, 1941

By I. W. Alcorn

The cost of drilling in the past few years of proration and ever decreasing allowables has received increasing thought and study. It seems to parallel the strides made with respect to pumping problems in 1932 and 1933. Low profit margins stimulate the search for economies. Any discussion of slim-hole drilling involves a multitude of abstract values, and the problem can be attacked only by a study of records and rational thinking. In a measure, traditional methods must be studied with a questioning attitude. The words "slim hole" may be somewhat misleading, as the term is entirely relative. For that reason I wish to define it as used in this discussion. On the Gulf Coast, I would define a normal hole as one in which 10 3/4-in. surface casing has been set and below which a 9 7/8-in. hole is dug. With this as a datum, holes of larger diameter below surface would be called "large holes," with 121/4 in. as the "extra large" class and holes of smaller diameter classed in the slim-hole range, 6 1/4 in. representing about the minimum size. The optimum size has not been definitely determined, but the preference is for a program that would call for setting 8 5/8 -in. surface casing and digging a 7 3/4 - in. hole. Different sections of the country might very properly deviate from this practice because of differences in depth, formations, regulations, or other factors. This paper will be confined to a discussion of the drilling of exploratory wells, as the drilling of this class of wells is quite a different problem from that of drilling a proven field, although many of the same considerations apply in both cases, as will be apparent. Although for many years shallow slim-hole and core-test holes of small diameter had been dug, it was not, I believe, until the fall of 1937 that serious consideration was given to its application in drilling wells 7000 ft., 8000 ft. and 9000 ft. deep on the Gulf Coast. This does not mean that nearly all such wells drilled on the Gulf Coast now are of the slim-hole variety, but only that efforts have been aimed in that direction with very encouraging results and there has been a very definite trend to reduce the size of holes, a trend that probably will continue. As to exploration policy, there appear to be two distinct and opposite views. The one usually followed in the past was more or less designed to "shoot the works" on one well. Generally on the Gulf Coast, the depth at which production might be obtained is limited by the drilling equipment and economics. With this thought in mind, wildcat wells are often planned with the idea of carrying the depth to 10,000 It., or even 15,000 ft. All of the possible hazards are anticipated and the general drilling and casing programs are so predicated. Such wells contemplate the drilling of large-diameter holes; the setting of at least one protective string of casing and an extensive coring policy, all of which finally adds up to an expensive well. AS opposed to this general policy is the slim hole. This, on the Gulf Coast, recognizes that new discoveries represent gam-

Jan 1, 1941

By I. W. Alcorn

The cost of drilling in the past few years of proration and ever decreasing allowables has received increasing thought and study. It seems to parallel the strides made with respect to pumping problems in 1932 and 1933. Low profit margins stimulate the search for economies. Any discussion of slim-hole drilling involves a multitude of abstract values, and the problem can be attacked only by a study of records and rational thinking. In a measure, traditional methods must be studied with a questioning attitude. The words "slim hole" may be somewhat misleading, as the term is entirely relative. For that reason I wish to define it as used in this discussion. On the Gulf Coast, I would define a normal hole as one in which 10 3/4-in. surface casing has been set and below which a 9 7/8-in. hole is dug. With this as a datum, holes of larger diameter below surface would be called "large holes," with 121/4 in. as the "extra large" class and holes of smaller diameter classed in the slim-hole range, 6 1/4 in. representing about the minimum size. The optimum size has not been definitely determined, but the preference is for a program that would call for setting 8 5/8 -in. surface casing and digging a 7 3/4 - in. hole. Different sections of the country might very properly deviate from this practice because of differences in depth, formations, regulations, or other factors. This paper will be confined to a discussion of the drilling of exploratory wells, as the drilling of this class of wells is quite a different problem from that of drilling a proven field, although many of the same considerations apply in both cases, as will be apparent. Although for many years shallow slim-hole and core-test holes of small diameter had been dug, it was not, I believe, until the fall of 1937 that serious consideration was given to its application in drilling wells 7000 ft., 8000 ft. and 9000 ft. deep on the Gulf Coast. This does not mean that nearly all such wells drilled on the Gulf Coast now are of the slim-hole variety, but only that efforts have been aimed in that direction with very encouraging results and there has been a very definite trend to reduce the size of holes, a trend that probably will continue. As to exploration policy, there appear to be two distinct and opposite views. The one usually followed in the past was more or less designed to "shoot the works" on one well. Generally on the Gulf Coast, the depth at which production might be obtained is limited by the drilling equipment and economics. With this thought in mind, wildcat wells are often planned with the idea of carrying the depth to 10,000 It., or even 15,000 ft. All of the possible hazards are anticipated and the general drilling and casing programs are so predicated. Such wells contemplate the drilling of large-diameter holes; the setting of at least one protective string of casing and an extensive coring policy, all of which finally adds up to an expensive well. AS opposed to this general policy is the slim hole. This, on the Gulf Coast, recognizes that new discoveries represent gam-

Jan 1, 1941