Search Documents

By Henry Wurtz

HERACLITUS, a sage of antiquity, called the dark philosopher, who refused a throne, preferring a hermit's cell, propounded, twenty-four centuries since, the maxim : [ ] War (or strife) engenders all things. This, though probably intended by Heraclitus to apply especially to the internal forces of nature, is often said, with equal reason, of the affairs of men. Controversial strife, whether fortunately or unfortunately, is a crucible through which all new discoveries in science, and all technical applications of science must pass-a test which they must all endure before they can become so vitalized as to germinate, so to speak, take root in the human mind, grow tip, and overspread the earth. The greater the number and the power of the elements arrayed against such a growth, and of the influences hostile thereto, the greater should be the inherent vitality of the germ, the more strenuous, skilful, and persistent its cultivators and upholders. During the decade last past we have had, in spite of the severe stringency of the times, an active growth of this kind in progress, whose prospective importance it would now be difficult to overrate. This is the movement which has for its motive the idea that, generally speaking, fuel should be gaseous in form, and which has for its goal the introduction into general public use of gaseous products, made by cheap and rapid processes and on a gigantic scale, distributed throughout our cities and towns in distribution-systems which shall be proportionately gigantic, and sold at prices which will bring such fuel within the means of the poorest householders. Personally, for ten years past, the writer has never failed, on occasions public or private, to urge his belief that the realization of this idea, deemed by him a certainty of the future, will bring about

Jan 1, 1880

By H. S. Rankin, F. A. W. Davis, R. A. Laurence, L. L. McMurray, E. C. Houston

This paper is coodensed from several reports by members of the staff of the Minerals Testing Laboratory of the Tennessee Valley Authority, on a series of experimental tests in the beneficiation of barite of the Valley area. These experiments were conducted upon a large number of samples taken from several mines in three different districts. The area contains numerous producing deposits, nearly all of which are hampered by the high iron and silica content of the ores. Because of the small difference in specific gravity between the iron oxide and the barite, a gravity separation is generally poor. The removal of the iron thus offers a special problem. Some of the operators have turned to magnetic separation to meet the shipping requirements for less than one per cent iron. The present experiments were conducted to determine the application of decrepitation or flotation in simplifying the concentration of the barite by removing the iron oxide and silica in one operation. Practically all the barite marketed in the area has been as "off-color" crude. The bleaching studies were made to determine the bleach-ability of the ores to alleviate this inferior grading, placing them on the market as bleached barite. Geology Barite has been produced at many places in the Tennessee Valley area, and prospects and minor deposits are known at many other places, but practically all the production of barite in the Valley has been from the Sweetwater district of East Tennessee. Other leading areas of former production are the Tazewell-Russell counties areas of southwest Virginia, the Del Rio-Stackhouse district of East Tennessee and western North Carolina, and the Fall Branch district of upper East Tennessee. The areas described in this paper are those from which samples used in the concentration tests were obtained.

Jan 1, 1942

By Allen L. Hatch

Perhaps the greatest challenge to the non-ferrous extractive industry, aside from discovery and cost reduction, is the continuous effort toward the total recovery of metals. This is-and must continue to be-a joint endeavor on the part of the miner and the smelter, the first to trend constantly toward that form of concentration most amenable to the smelter and the latter to upgrade technical efficiency on the product delivered. What follows will be a smelter's-eye view of the relative value of gold, silver, copper, lead and zinc as they each are contained in copper, lead and zinc concentrates. The variety of combinations is obviously of such a magnitude that it will be necessary to restrict the observations to fundamental concepts.

Jan 1, 1966

By J. J. Crowe, G. K. Burgess

PAGE, Theories of Allotropy of Iron........... 667 Previous Determinations of A2 and A3 in Iron........ 668 Critical Ranges as Determined by Expansion........ 669 Critical Ranges by Thermoelectric Observations........ Critical Ranges in Terms of Crystalline Structure....... 670 Critical Ranges as Detected by Mechanical Methods...... 670 Critical Ranges as Given by Electrical Resistance....... 670 Critical Ranges as Determined Magnetically........ 671 Critical Ranges as Determined Calorimetrically....... 673 Critical Ranges from Heating and Cooling Curves....... 673 Summary of Previous Determinations of A3 and A2 in Pure Iron.... 675 The Present Investigation............ 678 The Experimental Method........... 678 Arrangement of the Apparatus.......... 679 The Measurements of Temperaturc.......... 679 The Measurement of Time........... 679 The Thermocouples............ 681 Temperature Scale and Calibration of Thermocouples...... 681 Mounting of Thermocouples........... 682 The Differential Measurements.......... 682 The Furnace and Accessories........... 682 The Vacuum Pump............ 683 The Energy Supply............683 The Rheostat.............. 683 The Materials Investigated............ 685 Sources of Iron............. 685 Preparation and Description of Samples......... 685 Chemical Analyses............. 687 The Experimental Data............. 688 The Preliminary Observations.......... 688 The Definite Series............691 Description of the Plotted Curves........... 694 The Effect of Plotting at Different Intervals........ 694 The Curves of the Definite Series.......... 695 . The Curves of the Preliminary Series......... The Existence of Other Critical Ranges......... 696 The Microscopical Examination........... 697 Summary and Conclusions............ 698 Bibliography............... 701 Plates................ 704

Jan 1, 1914

By E. W. Davis

IF the tonnage of merchantable iron ore remaining in the Lake Superior district is divided by the average of the annual shipments for the past 20 years, it will be found that this ore supply will be exhausted in approximately 35 years. This computed exhaustion period would be an indication of the future activities of the iron-mining industry if it were not for the fact that merchantable ore is being manufactured from low-grade ore, of which there is an almost inexhaustible supply in the Lake Superior district. It is true that at present only the simplest of these low-grade ores are being concentrated to any considerable extent, but progress is being made with the treatment of the more complex ores, and now, in addition to 20 washing plants on the Mesabi Range, three plants are equipped with jigs for the treatment of ore that cannot be concentrated simply by washing. The latest addition to the ore-treating plants of the Mesabi Range is a magnetic roasting and concentration plant at Cooley, Minn., in which ore that cannot be concentrated either by washing or by jigging is roasted to the magnetic state and concentrated on magnetic separators. This plant is beginning its third season of operation, and while it is too soon to make definite predictions, there are strong indica-tions that this new process may make commercially possible the manu-facture of high-grade, merchantable iron ore from large quantities of low-grade ore now considered worthless. After the iron oxide contained in an ore has been converted to mag-netite, almost any desired grade of concentrate can be produced, using magnetic-concentration equipment of the types now in general use for the concentration of the natural magnetites of New York, New Jersey and Pennsylvania. The conversion of hematite (Fe203) to magnetite (Fe304) is easily accomplished by heating the ore to a dull red tempera-ture in a reducing atmosphere. The reaction is slightly endothermic, and while it requires 200 B.t.u. to heat to 900° F. one pound of hematite ore containing 45 per cent Fe, it requires only 100 B.t.u. to convert the oxide into magnetite. In the laboratory, using small quantities of ore, this conversion is very simple, but large furnaces suitable for commercial

Jan 1, 1936

On August 22, 1966, just 20 months after writing sales agreements with Japanese steel mills, Hamersley Iron Pty Ltd made its first contractual shipment of 52,000 tons to Yawata Iron and Steel Co Ltd. As world news, the event was not spectacular. But to mining men it represented an astonishing achievement. Twenty months of feverish effort and the expenditure of more than $100 million had created a large open-pit iron ore mine, a crushing plant, storage and load-out facilities for sized ore, and a supporting township at Mt Tom Price; a 182-mile standard gauge railway; and port and loading facilities for a nominal loading capacity of 6000 tph as well as a port town, Dampier, on King Bay. The project was executed in the sparsely inhabited, arid, dissected-plateau country of the Hamersley Range in the northwest sector of Western Australia. Hamersley, 60% owned by Conzinc RioTinto of Australia Pty Ltd and 40% by Kaiser Steel Corp, holds sale contracts for ore and pellets valued at $770 million. The main contracts are with the Japanese, who are to be supplied with 65.5 million tons of ore during the 16 years from August 1966 to August 1982 and 18 million tons of pellets over a 10-yr period beginning in early 1968. Of lesser importance at this time, but presaging trends, are contracts for a total of nearly 1.5 million tons to be shipped to England and Western Europe during the years 1966-68. A pellet plant with a capacity of 2 million tpy is now under construction at Dampier and is to be on stream early next year. Another interesting project for which the plans are set, is a desalination plant for sea water to supply industrial requirements and potable water for the town of Dampier.

Jan 5, 1967

W. E. RUDER, Schenectady, N. Y. (written discussion?).-To many members of the Institute, papers like this one by Prof. Jeffries, and that on "Reversal of Inheritance" by Prof. Howe, may seem highly academic. Aside from their direct application to all heat-treating processes, to my mind, the establishment of a physical fact and the correlation of facts into a definite law are in themselves ample justification for immense effort. A law, once established, cannot be ignored by those who carry the work along to practical ends. In studying both papers, it seems to me that each author is more concerned with defending a theory than with explaining the individual results as published by various investigators. Take, for example, my sample of pressed electrolytic iron, frequently referred to by both. Prof. Howe, defending inheritance, says that the grains on the second (1300° C.) heating inherited their size from the mother austenite. Prof. Jeffries, defending reversed inheritance, elabor-.

Jan 4, 1918

By Charles E. Glass

A steadily growing body of evidence indicates that earthquake ground motions can cause failure of rock slopes that are otherwise stable under static loading conditions. As a result, the economic optimum working slope angle is reduced when earthquake shaking is considered in surface mine design, especially in regions of high seismicity. When designing surface mine slopes to withstand seismic motion it is as important to consider the probability of experiencing various levels of ground shaking as it is to consider the characteristics of the ground motion. For most slope designs, simple probabilistic techniques such as extreme value or maximum likelihood techniques are appropriate. These techniques, however, should be applied in such a way that a probability value is assigned to characteristic ground motion parameters at the mine rather than to nearby earthquake magnitudes. Several techniques have been developed to analyze rock slopes subjected to dynamic loads. Most of these techniques do not adequately account for the ground motion parameters of concern. The best technique appears to be one that utilizes actual earthquake time histories. A simple technique that calculates block displacement for any input accelerogram, using a linear acceleration approximation between time steps, has been developed that accurately accounts for rock block response. Results using this technique indicate that the following factors are important for assessing rock slope stability in earthquake regions:

Jan 1, 1983

The Library of the above-named Societies is open from 9 A.M. to 10 P.M. on all week-days, except holidays, from September 1 to June 30, and from 9 A.M. to 6 P.M. during July and August. The Library contains about 55,000 volumes, including sets of technical periodicals and the publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their tine in localities isolated from sources of information. To these the Library can render valuable service through correspondence; letters requesting information will receive special attention. The Library is prepared to furnish references and copies of articles on mining and metallurgical subjects; to determine the existence of mining maps, and to furnish general information as to the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will -be saved, and the information will be sent more promptly and in more usable shape. The members of the Institute can be of service to the Library by forwarding copies of mining reports, maps privately issued, and similar material, which will be classified, indexed, and made available to other members. Suggestions for additions to the Library, either by purchase or personal solicitation as gifts, will be welcomed. It is hoped that members while in the city will use the Library freely, and assurance is given that most careful service will be rendered to them.

Jan 5, 1915

By Jennifer Drake, Edward T. Moriuchi, Jennifer A. Hill

SEAMSYS and CSD/SMP are sets of computer programs that assist geologists and mine engineers in modeling and evaluating coal properties. The systems are tailored for treatment of waste and coal quality data, including metallurgical coal product capabilities. The gridded SEAMSYS model honors all drillhole data and incorporates user- defined mining parameters, losses and dilutions, and operational constraints. A variety of reserve reports and graphic displays are available from the model. Preliminary mine planning is accomplished through automatic cut generation and production targeting. CSD/SMP refines the preliminary plans to help anticipate the consequences of various mine schedules and evaluate equipment capacity requirements.

Jan 1, 1983

By W. M. Morris

THE volumetric behavior of isobutane at temperatures below its critical temperature has been studied by several investigators. Seibert and Burrell1 measured the vapor pressure of isobutane from the ice point to the critical temperature. Dana and co-workers2 determined among other thermodynamic quantities the density of the saturated liquid and the saturated gas and the vapor pressure from approximately 0° to 130° F. Sage and Lacey3 studied a number of the thermodynamic properties of this hydrocarbon from 70° to 250° F. The specific volume in the gas and liquid region was determined at pressures up to 3000 lb. per sq. in. ? throughout this temperature interval. In addition, the vapor pressures were measured at 30° intervals. These data taken together serve to establish the thermodynamic behavior of isobutane at temperatures between 0° and 250° F. with reasonable accuracy. However, apparently there are no data available at the higher temperatures. For this reason an investigation of the volumetric behavior of isobutane at temperatures between 100° and 460° F. was carried out with apparatus that has been described in another paper (A.I.M.E. Tech. Pub. 1127).

Jan 1, 1939

By K. H. Nimerick, G. P. Laflin

Laboratory data and field tests indicate that substantial losses of valuable coal can be caused by wind erosion. Wind tunnel tests show the effects of wind velocity and particle sizing on the amount of coal lost while in transit. Different coals were evaluated to determine the variables associated with wind erosion. The erosion losses can be substantially reduced by using a binder, or crusting agent, to consolidate the surfaces of the coal into a solid mass which resists erosion. This not only reduces economic loss but minimizes polllution.

Jan 1, 1980

By I. R. Kramer

A study was made of the effect of surface-active agents an copper, gold, and zinc single crystals as well as polycrystalline aluminum. The study on coppw showed that the maximum effect of the surface -active agent occurred at the same concentration of the solution as that at which the rate of solution of the copper soap was the greatest. Surface -active agents did not affect the creep behavior of gold or freshly polished zinc specimens. The creel-, rate of zinc specimens in a solution containing a surface-active agent zoas always lower than that of freshly polished specimens. In previous papers1'2 it was reported that the surface played an important role in the plastic deformation of metals. By removing the surface layers of a crystal of aluminum by electrolytic polishing dur- ing tensile deformation, it was found that the slopes of Stages I, 11, and In were decreased and the extent of Stages I and I1 were increased when the rate of metal removal was increased. The results of the investigation of surface-active agents showed that changes in the slopes and extents of Stages I and II occurred when single crystals of aluminum were deformed in tension in a bath containing solutions of paraffin oil and stearic acid. The amount of change was a function of the concentration of stearic acid and the maximum effect occurred at a concentration of 0.002 mole per liter. These results were interpreted2 in terms of the rate of solution of metal soaps which form as a result of the chemical reaction between the surface-active agent and the metal. According to this interpretation, the "weakening" effect is controlled by the rate of solution of the soaps which depends upon the concentration of surface-active agents. At low concentrations, the number of metal soap molecules formed is low; at high concentrations, the rate of solubility is low, because of the high degree of saturation.

Jan 1, 1963

By Jack C. Jones, Hemendra N. Kalia

This paper is partially based on a comprehensive ground control investigation that was conducted by Harza Engineering Company under a contract from the Bureau of Mines. This investigation required in- stalling several types of ground movement indicating devices on the surface and in the mine. The major instrumentation systems consisted of hydraulic borehole pressure cells, multi-point extensometers, in- clinometers, convergence indicators, Jack pressure recorders time domain reflectometers, and a 200 station subsidence network. The investigation demonstrated the versatility of the system. We were able to install pressure cell s to a depth of over 200 feet in the coal bed and we were successful in installing 10 pen mechanical recorders to monitor differential strata movement. In this paper, we have briefly discussed data from 18 borehole pres- sure cells, two time domain reflectometer cables and four subsidence lines. The data collected showed that the front and rear abutment pressures were approximate1 y 1000 feet (304.81~1) to 1200 feet (356.76111) from the active face. The peak pressure was about 4 times the over- burden pressure.

Jan 1, 1983

By Charles Legrand

(San Francisco Meeting, September, 1915) THE problem of mine pumping is so much affected by local conditions, and those conditions are so liable to changes during the life of a mine, that the best system to use is difficult to determine. The experience of the;, writer has been that, in general, for copper mines, electric pumping is most satisfactory unless the quantity of water to be pumped is great or. the mine does not use electric power for any other purpose. As a rule, however, figuring on the cost of necessary power plant, the total cost of: installation is greater with electric pumps than steam- pumps. As the water is liable to be gritty, outside-packed plunger pumps are to be recommended, and if the water is not acid, or only slightly so, chilled cast-iron plungers pay for their extra cost very quickly in diminished cost of packing. With chilled plungers it is possible to use metallic, packing instead of soft packing, if the water, is not too gritty nor the lift too high. In vertical pumps this packing is satisfactory for lifts up to 400 ft., in the experience of the writer; and may be found satisfactory for higher lifts. For water slightly acid, cement-lined pump bodies have given good satisfaction. For acid. water, both plungers and pump bodies should be made of acid-resisting bronze. For high lifts, especially with gritty water, a satisfactory pump valve is difficult to find. To reduce the unbalanced pressure on the valve at time of opening it is advisable to have narrow seats; this, however, brings high pressure on the seats when the valve is closed. On large valves for lifts of 600 to 1,000 ft. we have used leather, hard rubber, vulcanized fiber, and soft brass; for clear water the latter has given best satisfaction. The difficulties due to grit make it advisable to have large sumps where water can settle, and if possible, to have two of them so that they can be cleaned alternately. At the mines of the Old. Dominion Copper Mining ,& Smelting Co.; Globe, it was found that a small air. ejector discharging into a mine car is a very convenient way to clean mud and sand from a sump. .

Jan 9, 1915

By M. H. Merriss

Some years ago, at the plant of the Baltimore Copper Smelting & Rolling Co., the receipt of large quantities of copper blister running high in lead, nickel, and arsenic resulted in the formation of a great amount of very foul slag, in the anode furnaces. A typical analysis of this slag was: Gold, oz. per ton......... 0.09 Arsenic, per cent.......... 0.60 Silver, oz. per ton......'.. 13.20 Antimony, per cent........ 0.50 Copper, per cent......... 19.50 Silica, per cent............ 28.30 Lead, per cent........... 11.90 FeO, per cent............. 19.20 Nickel, per cent.......... 4.60 CaO, per cent............. 1.60 The problem was to get out the copper in marketable form, to save the gold, silver, and particularly the nickel, and to get rid of as much as possible of the lead, arsenic, and other elements that were valueless to the Baltimore plant. In a copper refinery that does not take custom material for matte smelting, the usual method is to smelt the anode slag with coke in a reducing furnace, the black copper thus formed being sent back to the anode furnaces; this was the custom at Baltimore. An average anode slag will contain, perhaps, 40 per cent. copper and such small quantities of lead, nickel, etc., that smelting will get rid of most of these impurities in the black-copper furnace slag. To treat such an impure slag in this way, however, would result in a large nickel loss, and would send back to the anode furnaces all the lead and nickel not so lost, where it would be slagged off again and returned to the black-copper furnace as a slag still more concentrated in impurities. The result would probably be a constantly increasing amount of anode slag containing a likewise constantly increasing percentage of impurities. To avoid such a disastrous closed circuit some other process had to be devised. A small multiple-tank room, built for impure copper as an adjunct to the main series electrolytic refinery, was available, so the following standard process was suggested:

Jan 1, 1924

By Yap Chu-Phay

Although chronologically the Sb-Bi system was the first one studied by the writer, the theoretical basis of the equations used in this paper is fully discussed in the writer's paper on the iron-carbon system,' because he believed that many would be more interested in the iron-carbon alloys. He suggests, therefore, that the reader consult that paper to familiarize himself with the theoretical aspect of the thermodynamic treatment outlined herein. This paper is divided into two parts: Part 'I deals with the Sb-Bi system and Part II deals with the lead-rich side of the Sb-Pb system. Although the former system has not much practical interest now, it has great theoretical interest in that it is the one system that for a long time was thought to have (and under specific conditions still has) an anomalous solidus, which no amount of physical investigation could adequately account for. The latter system, of course, is particularly interesting in the lead-rich end. It will be shown that the thermodynamic method is capable of predicting reliably the equilibrium position of the solidus, and thus acts as a check on the experimentally derived solidus. PART I.—THE ANTIMONY-BISMUTII SYSTEM In connection with his studies in thermoelectric phenomena,-the writer was naturally interested in the system Sb-Bi. In consulting the International Critical Tables2 he found the constitutional diagram shown in Fig. 1 (not including Ôtani's solidus), essentially after Cook,³ who investigated the system carefully by thermal analysis. Note the isothermal crystallization of alloys varying in composition from about 48 per cent, (by weight) to pure Bi. This is anomalous, because, according to the phase rule, in a binary system when only two phases coexist, there is univariant equilibrium; that is, the composition changes with the tempera-

Jan 1, 1931

By J. F. Lewis

BELIEVING that one of the essential points in mining, as in all other business, is to know the expense incurred in each particular department, I have carefully kept an account with each department for the past three years; and, as it may be of interest to some of our members, I herewith present it to the Institute, reduced to percentages of the total yearly expense, showing the cost for materials, repairs, expenses, tools, team accounts, powder, oil, and fuel, also for labor under its several heads :

Jan 1, 1878

By W. B. Triplett, H. I. Aaronson, G. M. Andes

A detailed morphological study has been made of the pro-eutectoid TiCr, and the eutectoid reactions in a Ti-17.42 pct Cr alloy isothermally transformed at temperatures from 775° through 5561°C. The morphologies of proeute,ctoid TiCr2 were found to be subject to description by the Dube morphological classification system. Grain boundary allotriomo.lphs are the dominant plpoeutectoid morphology throughout the temperature range investigated. lntragranular plates, and especially Widmanstatten sideplates, form only in small numbers. This morphological pattern differs markedly from that of the proeutectoid a reaction in hypoeutectoid Ti-Cr alloys (AIME Trans., 1957, vol. 209, p. 1227; 1958, vol. 212, p. 624), in which plates form prolifically throughout wide ranges of temperature. The eutectoid reaction is nonlamellar in character at 675°C. An increasingly prominent lamellar component develops at lower temperatures. The proeutectoid TiCr 2 and the eutectoid transformations have been studied metallographically in a hypereutectoid titanium-chromium alloy. This investigation was undertaken with the immediate objective of comparing these transformations with their counterparts in hypoeutectoid titanium-chromium alloys, studies of which have been recently completed.1,2 It was also intended, however, to contribute to the general literature on transformations of these types. Especially in the proeutectoid case, this literature is still sufficiently sparse to make difficult the testing of generalizations on the mechanisms of these transformations. TiCr, is the only intermetallic compound in the titanium-chromium system.3-5 The TiCr2 phase field extends to a maximum temperature of 1350°C) and encompasses the approximate composition range of 62 to 68 pct Cr at lower temperatures.3'4 At temperatures below 1000°C, TiCr2 has a MgCu,-type fcc structure, with 24 atoms comprising a unit cell.6,7 Only fragmentary observations on the morphology of proeutectoid TiCr2 have been previously reported. An observation which is of considerable importance with respect to the results obtained during the present investigation was made, however, on anisother-mally transformed alloys with high chromium (48 to 70 pct Cr) contents.3"8 Despite the occurrence of extensive impingement, it is apparent that a substantial proportion of the proeutectoid TiCr, which precipitated in these alloys grew in the form of Widmanstatten plates. Several observations have been made on the eutectoid reaction in hypereutectoid alloys during investigations of the titanium-chromium phase di-

Jan 1, 1961

By K. P. Gupta

In ternary systems containing silicon and transition elements, silicon was found to stabilize the a phase.1 At 1000°C a broad a-phase region was found in the Cr-Mn-Si system,1 which extends very close to the Mn-Si binary line (within about 3 at. pct Cr). Later investigation showed that, if chromium was replaced by small amounts (3 to 5 at. pct) of v,1 Ti, Nb, Ta, Mo, or w,1 the a phase or the R phase was again stabilized. Whether stabilization of complex crystal structures is possible by small additions of iron, cobalt, or nickel to Mn-Si is not known. Investigation of the Co-Mn-Si system4 shows the presence of several ternary phases, but at cobalt concentrations higher than 10 at. pct. In the present work the ternary systems Fe-Mn-Si and Co-Mn-Si were investigated at low iron and cobalt concentrations (< 7 at. pct Fe or Co) in search of phases of complex crystal structure. Experimental Procedure. The alloys were pre-pared by induction melting Co (99.8 pct), Si (99.9 pct), electrolytic Fe (99.88 pct), and Mn (99.9 pct) in recrystallized alumina crucibles under an inert atmosphere of argon gas. The alloy specimens were wrapped in molybdenum foil, sealed in argon-filled (at 1/2 atm) silica capsules and annealed for 72 hr at 1000" 1°C, and water-quenched. The use of argon-filled capsules was found to reduce the losses during annealing and the molybdenum foil prevented reaction of the manganese with silica. The total weight loss due to annealing and melting was found to be less than 1 pct for each alloy. The alloys were not analyzed chemically. A part of each annealed specimen was polished and examined metal-lographically using etching solutions, a) 0.1 to 0.5 pct oxalic acid solution in water, or b) 0.5 pct HNOs in methyl alcohol. Even though the etching solutions were quite dilute, the specimens were heavily etched and stained if the etching time exceeded more than 5 sec. Etching times found suitable were usually 1 to 3 sec. For X-ray diffraction work, a part of each annealed specimen was powdered by crushing after the exposed surface was ground off. X-ray diffraction patterns were taken with powder specimens using a 20-cm-diam asymmetrical focusing camera and Fe K radiation. These powder patterns were found quite satisfactory for the purpose of phase identification. However, X-ray diffraction patterns of single-phase alloy powder specimens were also taken using a Siemens diffractometer and filtered Cr-Ka radiation for greater resolution of the diffraction lines. Results and Discussion. In the Fe-Mn-Si system a new ternary phase was found at 1000°C between the p manganese and the MnsSi phase regions. The approximate phase relationships in this region of the 1000°C isothermal section are shown in Fig. 1. The new ternary phase, designated as the K phase, was found to occupy a narrow region about 1 at. pct in width and extending from Fee.oMn74.5Silg.5 to Fe.Mn.Silg.. At the high-iron content region, the K phase was found in equilibrium with the p manganese and the MnsSi phases but, at the low-iron content end of the K-phase region, the phases in equilibrium with the K phase were the p manganese phase, the MnsSi phase, and another new phase, designated in Fig. 1 as the v phase. The v

Jan 1, 1964