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By W. Wanjokow, H. O. Hofman

In the metallurgical treatment of most metallic sulphides it is usually necessary to carry on a roasting-operation. In some cases the raw ore will have to be roasted; in others the intermediary product, matte, produced in smelting the ore; again, both ore and matte may have to be subjected to oxidation at elevated temperatures. Most metallic sulphides, when given an oxidizing-roast, pass through the state of sulphate before they are converted into oxides. All metallic sulphates are completely decomposed by heat, with the exception of those of lead and bismuth, but the temperatures at which decompositions take place vary with the metals. Some metallic sulphates are converted directly into oxides, others first form basic salts. Alkali-earth sulphates show a behavior similar to that of metallic sulphates, while alkali sulphates do not part with their sulphur trioxide even at elevated roasting-temperatures. The older data on the decomposition of metallic sulphates by heat are only approximations. Thus Kerl' gives the order in which metallic sulphates are decomposed with increasing temperatures as (Ag2, Fe, Cu, Zn, Ni, Co, Mn, Pb) SO,. More recent statenlents give definite temperatures and modify the formerly accepted order of decomposition. But the temperatures given by various observers do not agree. The reasons for this are to be found mainly in the method and manner of carrying out experiments. Four methods have been used: 1. Heating in an evacuated tube; 2, heating in a tube closed at one end, without air-cur-

Jan 1, 1913

By H. H. Uhlig

SINCE its first mention in the literature in the eighteenth century1,2 the phenomenon of passivity in metals has stimulated much speculation and attendant controversy as to its nature and cause. No one of the numerous theories so far proposed has been generally accepted. ? Faraday,7 in 1836, associated the passivity of iron with a protective film over the surface of the metal, which materially prevents or slows down reaction with corrosive environments. His theory was that oxidizing acids like nitric acid form an unstable oxygen or oxide layer over the iron surface, which protects the underlying metal from further attack. This concept was simple yet plausible, and without alteration has frequently been assigned in present-day discussions as explanation of the passivity of many metals. With the advent in recent times of stainless steels, it is not surprising that this oxide film theory of passivity proposed by Faraday has been used to explain the phenomenal corrosion resistance of stainless steels and other passive alloys. The passive alloys, such as the chrome-iron alloys, are supposedly covered with a protective oxide film, which forms on exposure of the alloy to air, is extremely stable and self-healing, and accounts for the remarkable resistance of these alloys to corrosion. Within the past few years, several investigators, following the theory of film protection, have attempted to gauge the resistance of the supposed film on steels. Brennert8 and Donker and Dengg9 determined the poten-tial at which a negative ion (e.g., Cl-) moving in an electric field reacted with the metal anode, as detected by increased current flow or change in potential of the steel electrode in an electrolytic cell. The potential corresponding to reaction Brennert called the film break-through potential.

Jan 1, 1939

Primarily, 1961 was a year for widespread application of tools and techniques which have become operational in the past several years • • • Raising --Raise climbers and climber raising techniques have been improved; narrow veins as low as 55° dip are now being mined from climber raises. Climber modifications include: larger motors, tighter radius curves negotiated, improved lubrication and new methods of stowing the climber during a blast. Climber raises are now ventilated in several ways: a 12-in. diam flexible vent tube behind the climber rail; a 6-in. diam pipe behind the climber rail (with fan); or a 6 to 8-in. diam drill hole along the axis of the raise. In hot raises, these ventilating techniques have resulted in more rounds per shift. When driving raises from crosscut and lateral development, mucking machine loading of raise rock is preferred over slusher ramp loading for the following reasons: a) faster set-up and teardown of climber facilities; b) easier access for climber maintenance, repair and loading of raising supplies; c) area at the bottom of the raise can be kept cleaner. Both wide and narrow veins are mined from 7 x 7-ft climber raises at Butte and at Republic, Wash. At Republic, climber rollers have been modified to support increased weight when driving 55°dip raises • Drilling-The new largebore, short-stroke push feed drills are much faster drilling than previous models and are most satisfactory in hard ground. Although reports on maintenance studies of the new drills are not yet available, increased steel and bit wear and breakage, and increased drill maintenance are seen as potential problems. Mines in Montana and Idaho continue to test rubber-collared drill steel. The fabricating methods used are successful but advantages in increased steel life have yet to be proved. Underground applications of down-the-hole drills continue. Drilling speed and accuracy are reported as the outstanding advantages. Manufacturers are now hopeful of making drills which will operate in any direction. Present applications are for ventilation holes (to 8 in. diam) for climber raises, holes for hydraulic fill distribution, drain holes and "predrilled" raises. Good drilling accuracy has been reported to a depth of 200 ft. Cutting holes in drifting is seen as a future application

Jan 2, 1962

By R. I. Jaff, H. R. Ogden, D. J. Maykuth

A phase diagram for alloys containing from 0 to 66.9 pct Mn was determined. Two compounds, tentatively labeled 6 and y, were found in this range. The 6 compound is located at about 66.9 pct Mn and melts congruently at 1330°C. The ? compound has a composition near 53 pct Mn and originates in a peritectic reaction at 1200°C between liquid and 6. ß and Y enter into a eutectic reaction at 1175°C. The ß phase field terminates in a very sluggish eutectoid reaction between a and ? at 550°C. MANGANESE is one of the important alloying addition elements to titanium. As a ß-stabiliz-ing addition for a-ß and ß alloys, it provides high strength with adequate ductility.' Two of the earliest commercial alloys contain manganese as a major alloying component.' The earliest published data on the constitution of Ti-Mn alloys was that of Wallbaum,~ who reported the existence of the compound TiMn2. The transformation range of commercial-purity Ti-Mn alloys was investigated by Craighead, Simmons, and Eastwood' who found limited a solubility and a lowering of the ß transus to about 790°C at 7 pct Mn. Preliminary work by the authors of this paper, using high-purity titanium, confirmed the ß-stabilizing action of manganese and showed the existence of several intermediate phases in the Ti-Mn system." More recently, McQuillan3 determined the ß transus temperatures for high-purity Ti-base alloys containing up through 4.4 pct Mn. These data are given in Fig. 1. The present investigation covered alloys made with a high-purity base. The constitution of titanium-rich alloys made with commercial titanium has been reported4," by Holladay, Kura, and Jackson. The alloy range covered in the present investigation was from 0 to 69.5 pct Mn. This alloy range extends slightly beyond the composition of the first congruent-melting compound encountered on proceeding from the titanium end of the system. A description of the materials and methods used in the determination of the diagram is given in the Appendix. The partial phase diagram determined for the Ti-Mn system is shown in Fig. 2. Details on equilibria in the titanium-rich alloys are given in Fig. 3. Liquid-Solid Relationships Observations on the cast structures of the arc-melted ingots showed that the terminal solid solution of manganese in ß titanium enters into a eutectic reaction with an intermetallic compound labeled ?. As will be shown later, this compound has a composition around 53 pct Mn. The eutectic reaction temperature was determined as 1175°C by thermal analysis which also showed that the ? phase originates in a peritectic reaction at 1200°C. Fig. 4 shows typical eutectic structures for alloy compositions on both sides of the eutectic composition which is located at 42.5 pct Mn. In alloys over the range of 45.4 through 69.5 pct Mn, a second intermetallic compound, labeled 6, was identifield as the primary phase. This phase consistently increased in amount as the manganese content approached 66.9 pct, and, as shown in Fig. 5, an alloy structure containing 66.9 pct Mn consisted essentially of the 6 compound. Thermal-analysis data indicate a melting point of about 1330°C for the 6 intermediate phase. At 67.0 pct Mn, small quantities of a new, higher manganese-content phase were observed in the form of Chinese-script eutectic particles. Comparison of Fig. 6a and b shows an increasing quantity of this phase as the composition was increased to 69.5 pct Mn. The formation of peritectic ? in arc-melted alloys containing 45.4 pct Mn and above appears to be almost entirely suppressed, as shown in Fig. 7a and b. This is because of the narrow freezing range available for its formation by peritectic reaction and because of the very high cooling rates obtained in

Jan 1, 1954

By J. A. Norden

MUCH has been written concerning the hoisting equipment of various mines -throughout the country, but most of the literature on the subject, if not all, describes equipment of extraordinary capacity and the small and medium-sized outfits have been neglected. The hoisting equipment here described is capable 'of handling about 1200 tons per day. It has not been worked, to capacity, but 600 to 700 tons, together with men and materials, have been handled in two shifts without any great effort. Only one shaft extends from the surface to the lowest levels of the mine; see Fig. 1. It is composed of three compartments, two of which are used for hoisting and the third for water, air, and electrical lines, and for sinking purposes. In 1909, this shaft was raised from the 1000-ft. (304-m.) level to the 700-ft. There a station was cut and an air hoist installed. At this time all mining operations were confined to the upper levels of the mine; that is; above the 700-ft. The. ore was-dropped to this level through chutes from the 300-, 400-, 500-, and 600-ft. levels and then lowered in cars on cages to the 1000-ft., which is the main haulage adit, the mill and railroad bins being about 3000 ft. from the shaft. Orebodies were, in due time, developed on the 1000-ft. level and below. Therefore, in 1913, the shaft was sunk to the 1150-ft. level and thereafter sinking was continued at regular intervals until the 1500-ft. level was reached. But, hoisting from the 1300-ft. level was a difficult, and slow process with the antiquated air hoist, so, in 1916, it was derided to raise the shaft to the surface and install a modern, electrically operated hoist. This was completed early in 1917 and the hoist was in operation in March of that year.

Jan 8, 1920

By D. J. Reed

Concord coal mine near Bessemer, Ala., built, owned, and operated by Tennessee Coal & Iron Div., U. S. Steel Corp., produces only a metallurgical grade for use as coke in blast furnaces of the division at the Fairfield and Ensley works. Capacity of the operation is approximately 800 tph, half of which is delivered to the coke and coal chemical plant at Fairfield after beneficiation to metallurgical grade coal. The remaining portion of the mine run is rock and refuse removed during preparation. Concord mine coal is hoisted to the surface coal preparation plant by an underground slope conveyor. The slope conveyor is 2449 ft long and has a lift of 729 ft. At time of installation the Concord mine slope conveyor was the largest single conveyor unit ever made with respect to belt horsepower and total lift. After several years it became necessary to determine the cause of slope conveyor cover wear.

Nov 1, 1956

[Alphabetic Section (Page 689): The letter immediately following the member's name indicates grade: M-Member, A-Associate, J-Junior. The numerals following member's grade indicate year of election. The letter following year of election indicates primary Divisional affiliation: A-Mining & Exploration F-Coal B-Minerals Beneficiation G-Petroleum C-Iron and Steel H-Industrial Minerals D-Extractive Metallurgy J-Council o f Education E-Institute of Metals K-Council o f Economics]

Jan 1, 1961

By L. H. Schwartz, M. V. Nevitt

THE phase Ti2Ni has been described by Laves and Wallbaum,1 who found the phase to be face-centered cubic with 96 atoms per cell, by Duwez and Taylor,2 who confirmed these observations and reported a lattice parameter of 11.333A, and by Rostoker,' who reported the structure to be isomorphous with the double carbide Fe,W,C, type E93, and to have a lattice parameter of 11.29A. In this study a group of isostructural phases has been found among alloys of certain second and third long-period transition elements. The systems investigated included all the combinations of zirconium and hafnium with the Group VIII elements rhodium, palladium, iridium, and platinum. There is evidence that many of these new Ti2Ni-type phases require oxygen for their stability in the temperature ranges in which they were studied. EXPERIMENTAL PROCEDURE Alloy samples weighing 5 g were prepared by arc-melting metals whose purity is indicated in Table I in a helium-argon atmosphere. Samples of the as-cast buttons, wrapped in molybdenum foil and sealed in evacuated quartz tubes, were

Jan 1, 1959

By Frank H. Macpherson

Few people realize the tremendously important part that Saline and Pulaski Counties in central Arkansas have played in the winning of the war The present favorable war situation might have been very different if we had not had the bauxite produced during the past two years from these two small areas, a total Of about 15 square miles. As a general statement, it can be said that the Arkansas bauxite deposits are, individually, relatively small, irregular in thickness, somewhat scattered and, therefore, compared with coal or iron-ore or open-pit copper deposits, relatively ill adapted to a rapid and drastic expansion in output. A few years ago it would have seemed an impossibility for these two counties to produce over six million long dry tons of bauxite in one year. However, with the cooperation of the operators, that is what happened in 1943, when the state of Arkansas achieved the seemingly impossible with a production of 6,020,684 1 long tons (dried equivalent) of bauxite ore during the calendar year, compared with an average annual production of 323,7252 tons in the period 1931 to 1941. It became apparent early in the year '94' that the united States soon might be drawn into the war, and, therefore, that an immediate study of the domestic metal situation was necessary. Aluminum is by far the most important metal used in the manufacture of aircraft and many other implements of war and it was evident that there would have to be a tremendous increase in the domestic production of bauxite, which is practically the only present source of this metal. AS more than 95 per cent of the known bauxite reserves of the United states was in Arkansas, careful preliminary studies were made in that state by representatives of the united States Bureau of Mines, the United States Geological survey and the War Production Board in the summer of 1941 Reserves in other states also were studied. The result of these studies was a recommendation by the War Production Board that mining in the bauxite.producing areas of Arkansas be geared for maximum production, in order to supply sufficient ore for this country's war requirements and, if necessary, to supply the war needs of Canada as well. The annual goal of eight million long tons (dry weight) set for Arkansas by the war Production Board was exceeded in 1943, when in August the output reached a rate equivalent to more than 8,300,000 long tons, dry basis. Because of the comparatively small tonnage of bauxite reserves, Congress appropriated funds for an extensive drilling program to be carried out by the Bureau of Mines in cooperation with the Geological Survey. Drilling began in May 1942 but owing to delay in delivery of drills, and trucks upon which the drills were mounted the program did not get into peak operation until early in 1943. By the end of July 1944, the Bureau of Mines records indicated an addition to the Arkansas reserves of 10,000,000 long tons (wet basis) in place,

Jan 1, 1946

By R. A. Hadfield

It seems a specially fitting opportunity to present a paper on the alloys of iron and aluminum at the New York meeting of this Institute, owing to the fact that America has, more than any other country, originated and developed the manufacture of cheap aluminum. The Cowles, Castner, and Hall systems have all originated in the ever-busy brain of our cousin across the water. The problem of cheaply producing this valuable metal has been a difficult one, but to the writer it seems that the more arduous the task the greater the delight with which our American friend attempts to overcome the difficulties surrounding it, and the more vim he throws into the work. Another and equally striking proof of this is to be found in the recent appearance of the already wellknown remarkable work, The Mefallurgy of Steel, by Mr. H. M. Howe, of the Institute of Technology, Boston, Mass. It is to be hopel that this Institute will not be slow to recognize by some special mark its appreciation of this signally valuable and original work. The writer has been led to describe the following experiments, believing that so far no full and exact report has yet been presented to this Institute as to the effect of aluminum alloyed or combined with the metal iron. It has been a special object to make the material as far as possible a true alloy or combination of aluminum and iron, with as small quantities as possible of other disturbing ingredients, such as silicon, manganese, etc. In the material described in these experiments, the total amounts of other elements present (sulphur and phosphorus being disregarded as present in such small quantities) do not exceed about 0.5 per cent. Such material may therefore be probably taken as fairly illustrative of the effect of the metal aluminum upon iron. Since completing the experiments the writer

Jan 1, 1891

TITANIUM is one of the most abundant elements in the minerals that make up the earth's crust but its use in industry is only a generation old; yet probably no other important commercial mineral raw material (except possibly magnesium) has undergone more changes and developments in sources of supply, in processing techniques, in uses and applications, in the past 10 years, or stands on' such a threshold of still more advances. Its outstanding use today is as the oxide, and because of its extreme whiteness, high refractive index, chemical stability, and relative cheapness, it has become the white pigment used in the largest volume. New developments in the uses of titanium metal, potential and actual, may surpass the pigment use of the oxide before many years. TITANIUM-BEARING MINERALS Although a number of minerals contain titanium as the principal metal, only a few are of commercial importance. These are arizonite, ilmenite, and rutile. The other oxides, brookite, pseudobrookite, and anatase, occur in a few deposits, one at least of minor importance. The silicate titanite, and the double oxide of calcium and titanium, perovskite, occur in a few deposits in quantities sufficient to be considered as potential ores were not richer deposits of the oxides available elsewhere. Arizonite is a name given by Palmer46a to a mineral found some years ago in minute quantities in Arizona, which has the formula Fe203.3Ti02. Unexpectedly, it was found that the black titaniferous iron oxide found in large quantities on the beaches of many continental land masses corresponds in chemical composition to this formula (although ferrous oxide is always present). No one has yet been able to prove that the commercial mineral on the beaches is truly arizonite, or an allotropic modification of it, since X-ray investigations by Howard Carl and A. F. Gabriel, of the U. S. Bureau of Mines, and by the X-ray laboratory of the Chemical Department at the Experimental Station of the du Pont company, have shown only that the sand mineral gives just a jumble of lines, rather than an identifiable pattern. Lack of a better name,

Jan 1, 1949

By Magnus Troilius

SINCE the discussion on steel rails in America has forcibly drawn attention to the value of chemical analysis, if not as a necessary stipulation, at least as a guide to control the usual mechanical tests, some doubt has been thrown upon the accuracy of the analytical results obtained by different chemists. To any one having the least acquaintance with chemistry, it is quite clear that if exactly similar results are to be obtained from the same borings of steel, exactly the same methods must be used by the different analysts. Hence the necessity (if complications are to be avoided) of establishing what I may call standard or normal methods, to be used both by the inspectors and by the chemists at the works. Remembering that the application of chemistry to steelrail inspection is yet in its infancy, it is of great importance to possess a perfect acquaintance with the best methods in use. Being myself a grateful pupil of Professor Eggertz, of the School of Mines in Sweden, it occurred to me, two years ago, that I could not do better than start a laboratory of my own, and engage one of his pupils, Mr. Troilius, for the purpose of analyzing the steel borings from mechanically-tested rails, so that I might thus obtain without delay thoroughly accurate determinations. Moreover, in order to carry on the operations in perfect accordance with the methods used at the steel works in England and Germany, where I had to control the manufacture, I deemed it desirable to allow Mr. Troilius to go through a course of training at these works; and I gladly seize this opportunity of expressing my grateful acknowledgments to several works in England and in Germany for affording every facility for such an exchange of information as mas found necessary in arriving at the best analytical methods to be used.

Jan 1, 1882

By Charles M. Romanowitz

The motivation for the art of dredging for placer mining can be compared in a slight degree to the spread of civilization which started in the Near East and spread both east and west. Dredging started with the "bag and spoon" dredge in the lowlands of Europe reportedly about 1565, went southeast to New Zealand where designs were developed for a bucket-line mining dredge known as the New Zealand type, and westward to the eastern United States where a dredge was developed and used exclusively for excavating. Then it moved to Montana, where it was first used for mining in 1895. The New Zealand-type dredge was imported into California in 1898 (Fig. 1) and was followed shortly by the Montana design. As today, these early dredges were equipped with continuous bucket- line chains, a treatment plant, and a means of waste disposal mounted on a wooden hull. Both types of dredges are complete mining units: they dig the formation, transport the dug materials, and concentrate the valuable ore. After sizing, the fines containing the ore are passed by gravity to the treatment unit, while the barren materials are discharged overboard. By digging the materials to be treated at the bow and depositing all the waste, at the stern, the dredges automatically advance to new reserves without presenting any transportation problems. The main differences between the two types are in the method of holding the dredge in the digging position and in the disposal of the tailings to the rear. The New Zealand type (Fig. 2) uses the headline system with a bow anchor for holding the dredge in the digging position and long tailing flumes or short stackers off the stern for disposal of the barren materials. The California type (Fig. 3) uses box girder spuds projecting into the ground in a vertical position at the stern of the

Jan 1, 1969

By William H. Grady

FactoRs entering into the market value of coal are its grade, and the cost of labor, material, and capital. Reduction in these costs cannot be expected in the future, and it therefore follows that greater economy in their use must be accomplished if it is desired to hold the present markets; more tons of product per unit must be obtained in a given time from both men and material, and means devised for increasing the percentage of lump and domestic sizes. This paper is presented for the purpose of inviting discussion and stimulating thought in regard to the influence of methods of procedure and plans of mining, upon the quality of coal, the economical use of labor, material, and capital, and the cost of production. Even the better methods of the present day leave much to be desired, and a review of the reasons and necessities for their use may be of value in pointing the way to more economical mining. The writer does not attempt to discuss untried methods of mining, but rather to state clearly and concisely a summary of the results obtained under the several methods of procedure that have been adopted. In some instances a high degree of concentration has been effected, and comparisons of the results obtained with the results of lesser degrees of concentration form an interesting study. It is believed that much may be accomplished in improving the quality, and in the more economical use of labor, material, and capital, by concentration, and it is to concentration in particular that your study is invited. The writer, who has occasion to visit many mines, most of which are under different management, has been inclined to the opinion that improvement has been retarded in many ways and that mining has not as yet been entirely freed from the early-day practices which were forced upon it. Practices resulting in lack of concentration, to which reference will be made, are: The absence of robbing, necessitating the frequent interposition of barrier pillars; lack of system and of proper supervision, resulting in losses of life and coal. These practices could not well be

Jan 1, 1915

By Reinhardt Thiessen

UNDER sulfur in coal, is usually understood that form of sulfur which is combined with iron and known as pyrite. It occurs in the form of halls, lenses, nodules, continuous layers, thin sheets, or flakes, both in horizontal planes and vertical cleavage fissures. But pyrites also occur as very fine microscopic particles, or nodules, disseminated through the compact coal. This form has had but very little consideration. Finally, there is sulfur in coal in an amicroscopic form (not visible with an ordinary microscope), probably combined with the organic matter that exists -in tile coal. This form has had considerable attention from a scientific standpoint, but has probably not been recognized enough on the economic side. One or the other, or both, of these two latter forms may comprise the larger part of the sulfur content of coal, especially after it has been washed or otherwise prepared for use.

Jan 9, 1919

By C. E. Sims, G. A. Lillieqvist

The following presentation is more a summation of observations made and conclusions drawn over a period of three to four years than a report of experiments made with a definite objective. Tests were made, of course, to verify hypotheses, but the large mass of data was collected incidental to other work. Lack of space forbids the presentation of more than a few of those data. On the other hand, it is unfortunate that some of the most illustrative examples are not available. The work is admittedly incomplete but is presented in the hope that it will stimulate further work along a similar line. The answers to many of the questions left unanswered by this paper will be found only after long and painstaking study, such as is scarcely possible in a commercial laboratory where problems of immediate importance consume most of the time. It is also hoped that this study will in some measure throw light on some of the dark spots of steelmaking, and help to clarify some of the annoyingly vague references to "good practice." Only cast steel was studied and the conclusions apply to cast steel, but it is the authors' opinion that the quality of rolled or forged steel is largely dependent on the quality of the ingot, which is a casting. Although this discussion deals almost entirely with inclusions, it is important that the reader understand that only those natural inclusions which owe their origin to the solubility of certain materials in steel and to the chemical reactions of steelmaking are considered. Accidental inclusions, such as entrapped particles of slag, nozzle, runner, or mold arc outside its province and are not considered. Such accidental inclusions are always dangerous and should be carefully avoided. Relation between Ductility and Nonmetallic Inclusions In September, 1928, an acid electric furnace was put into operation at the Indiana Harbor plant of the American Steel Foundries. Following the usual practice, aluminum additions were made in order to obtain sound castings. Immediately the problem of low ductility arose. Previous to that time, only open-hearth steel was produced, and, aluminum being used rarely in that steel, there had been practically no trouble with low ductility in the lower carbon range.

Jan 1, 1932

By J. H. Nelson

An outline survey of the economic outlook for the United States export trade in petroleum products resolves itself broadly into two general divisions; first, a consideration of our present position in this trade, and second, a discussion of the visible factors which promise to affect appreciable changes in the immediate future in that trade. The United States PetRoleum Exports of majoR Petroleum Products 1925, 1926 and 1927

Jan 1, 1928

Jan 1, 1924

By W. J., Kroll

MOST people believe that rare metals are always, scarce in nature, expensive to make, and therefore useless despite some miraculous properties which might make them a cure-all. There are' some metals, which are quite frequent in nature, such as zirconium, which are called rare only because our present methods for making them are elaborate, thus forcing the manufacturer to sell them at a high price. There are also truly rare metals, such as gallium, which do not occur frequently in ores, but are easily reducible from their oxides. In these cases the price of the concentration operation is the decisive factor. The distribution of the elements in the earth's crust is no indication as to the availability of a metal; the concentration operation is the critical factor. Concentration is frequently obtained in the course of metallurgical operations for the extraction of other metals, and the rare metal may be enriched in by-products, flue dusts, mother liquors or precipitates from electrolyte purification as are indium, thallium, selenium, and tellurium. A periodic table of the rare elements may serve as a basis for discussion of their properties and to establish a program. (Table 1.)

Jan 1, 1946

By T. L. Joseph

THE invention of the Bessemer converter process in 1856 added great impetus to the manufacture of steel and is one of the outstanding contributions to process metallurgy. Although the process of refining pig iron by passing air through the molten metal bears the name of Henry Bessemer, it should be mentioned in passing that William Kelley of Eddysville, Ky., worked on the process as early as 1847. Kelley was granted a patent on the process in 1857, inasmuch as he was able to prove priority in discovery.1 After considerable litigation in 1865 the respective interests of Kelley and Bessemer were combined. On Sept. 10, 1856, Robert Mushet of England obtained his first patent on the application of manganese to cast steel. Mushet anticipated trouble in purifying iron by passing currents of air through it. His patent specified that steel made in this way often contained flaws and was red short or cold short. Mushet understood the refining of pig iron into steel well enough to realize the difficulties likely to be encountered from oxidation of the iron. Mushet was not only an inventor but he was also an investigator. He understood the principle of selective oxidation which takes place in the converter process, arid he realized therefore that the remedy for over-oxidation was attainable if a suitable metal could be found at a reasonable cost and in sufficient quantities. His first experiments were made in small crucibles holding a few ounces of metal. Later his work was conducted on a larger scale and with complete success. Manganese had been used in making steel a quarter of a century before the converter

Jan 5, 1927