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By Eric R. Jette, Earl S. Greiner

The constitution of the iron-rich iron-nickel-silicon alloys at 600ºC. has been determined by X-ray crystal structure methods. If the results are represented isothermally by a conventional equilateral triangular plot, the single-phase solid solution (body-centered cubic structure) of the iron-rich alloys at 600°C. is bounded by four two-phase areas. Three three-phase areas separate the respective two-phase areas. Three of the phases in the polyphase areas have the same structures as the corresponding phases in the binary iron-nickel or iron-silicon alloys. There are two phases, however, that have not been reported previously and whose structures have been tentatively identified in the present investigation. The solid solubility limit of the iron-rich solid solution at 600°C. was determined by comparing the lattice constants of this body-centered cubic phase in the single and polyphase areas. It has been shown that the lattice constants of ternary alloys may be represented by surfaces whose distances above the ternary plot (representing atomic composition) are proportional to the lattice constants of the respective alloys. Then the intersections of the surface for the single-phase alloys with those for the corresponding phase in the polyphase alloys, at the respective temperatures, are the solid solubility limits of the single-phase alloys at these temperatures. The data of the present investigation were evaluated by this method, although by a system of orthographic projection it was possible to represent the three-dimensional model in two-dimensional diagrams. This investigation has shown that the solid solubility of nickel in the body-centered cubic phase of the iron-rich iron-nickel-silicon alloys at 600°C. changes from 3.7 weight per cent (Owen and Sulley) in the binary iron-nickel alloys to 5.0 per cent in the ternary alloys containing 4.8 per cent silicon. Further additions of silicon increase the solid solubility limit of nickel to 16.0 per cent at 12.6 per cent silicon. From this point the limit decreases to 9.5 per cent nickel at 15.5 per cent silicon and is, of course, zero at 15.3 per cent silicon in the binary iron-silicon alloys.

Jan 1, 1943

By R. E. Zimmerman

Wide attention is being placed upon various methods for cleaning the fine sizes of bituminous coals. The author describes and analyzes the results achieved on wet concentrating tables of modern design on unclassified feeds of —Vz in. particle sizes, including tests on high-sulphur coals. THE increased economic necessity of cleaning the small sizes of coal has forced wide attention upon various methods or processes being used. Although numerous cleaning plants in the past have been cleaning coal smaller than Vz or % in., the large quantities of higher ash fines being produced by mechanical mining and the need for cleaner coal under competitive market conditions have brought about many new installations of fine-coal cleaning plants. Of various methods used, one of the more popular types is the wet concentrating table. Approximately 525 tables have been installed in the United States in the past four years of which 320 have been installed in 20, large new plants. There are now probably 1600 tables of all types in existence in this country for cleaning coal. The purpose of this paper is to describe the cleaning of fine coal by wet concentrating tables. Its scope is confined to a discussion of the theory of tabling and some of the factors entering into tabling action, a description of the Deister SuperDuty diagonal-deck coal table and a discussion of the results of tabling various fine sizes of coals. Al- though tables have been used for cleaning coal as coarse as 2 in. and favorable results are reported, this paper is limited to reporting on the results of cleaning coal fines from 1/2 in. down. Also, although it is well known that the performance of tables is even superior under classified or closely sized feed conditions, this paper concerns itself with the results achieved by tabling unclassified feeds. History of Wet Concentrating Tables The wet concentration of minerals by some form of tabling is quite old, starting originally from fixed, smooth surfaced, tilted boards taking advantage of the laminar flow of liquid films and the separation of minerals according to specific gravity. This was followed by the development of rough deck surfaces

Jan 1, 1951

By A. W. Faheneald, Lewis S. Prater

By taking advantage of the fundamental difference between screening and classification—namely, that specific gravity has no effect on screening but is one of the important factors in classification—a combination of the two may be used as a process of mineral concentration. Although this fact is not new, so far as is known it has had little or no commercial application. The scheme is not presented now as a process for producing finished products but rather as a preliminary operation rejecting part of the barren material from an ore before it is subjected to more costly treatment. That is largely the function of the new heavy-media concentration processes that have been widely accepted. Original installation costs for the present sink-float processes are relatively high, however, which confines their use to operations where large tonnages are handled. Sink-float has been successful on only the relatively coarse (approximately plus 10-mesh) portion of an ore, and it is in this same range that classification screening can function most satisfactorily. Theoretically, there is no upper limit to the size of particles that can be handled in a sink-float operation, but the degree of liberation in the very large pieces usually limits this. With classification screening, particles from % to % in. would be the largest that could be handled, but the lower range could be extended somewhat below 10 mesh. In order to take full advantage of the difference in specific gravities of the minerals being separated, sorting in the classifier should be under as extreme hindered-settling conditions as possible. Laboratory tests have been made on a galena ore and on an artificial mixture of quartz and magnesite to determine the separations that may be expected. Although more than one scheme may be followed, in these tests the separations were made by cutting the underflow from the classifier as a concentrate and then screening the overflow. The screen oversize was rejected as a tailing. Classification was done in a hindered-settling teeter column and screening was done by hand, using the standard 4 2 series. The accompanying flowsheet gives the testing procedure followed.

Jan 1, 1947

By Arthur Braid

THE war has caused an increasing scarcity of phosphorus and its well known alloys with copper and tin. At the same time, the production of brass and bronze, nickel-silver, cupro-nickel, and other non-ferrous alloys, has considerably increased. The manufacturers of these products had therefore to secure other materials which would serve their purpose; principally that of a deoxidizer, which could be. obtained promptly and regularly. Fortunately these materials, pure carbon-free manganese metal and manganese-copper alloy, were not hard to find-in fact, they were never lost. Manganese in various forms has been used in Europe for more than a century; in this country, however, when manganese was first used, and indeed for a long time thereafter, it was consumed mainly in the- manufacture of manganese-bronze. Many foundrymen at that time used manganese-copper with the same freedom as phosphor-copper. Although iron enters into the composition of certain- grades of bronze, it is very detrimental to non-ferrous mixtures in general; consequently ferro-manganese is not applicable, and therefore pure manganese metal, or the alloy of manganese and copper, technically free from iron and other impurities, is now being generally used. The following are the principal elements having an affinity for oxygen: 1, Sodium. 2, Potassium. 3, Calcium. 4, Strontium. 5, Barium. 6, Magnesium. 7, Aluminum, 8, Phosphorus. 9, Silicon. 10, Manganese. 11, Iron. 12, Zinc. 13, Lead. Each metal has its natural flux, or deoxidizer, in the form of a metal or non-metal which will alloy with it, and has a strong affinity for oxygen. For example, phosphorus, as is well known, acts very beneficially in copper alloys that contain tin. Within 'the last few years, and particularly since the war began, the great value of manganese in nickel alloys has been demonstrated, and one by one the manufacturers of these products have adopted its use. While manganese has not so strong an affinity for oxygen as magnesium, aluminum, or silicon, it is nevertheless sufficiently powerful to reduce any oxide of nickel, copper, or zinc that may be present in the nickel alloy to be purified.

Jan 11, 1918

By N. M. Langdon

ON account of its greater economy and cleanliness, and the extent to which iuferior fuels can be utilized for its generation, there has been of late a rapidly increasing tendency to substitute gaseous for solid fuel for metallurgical and other industrial purposes, which has led to various improvements both in the process and apparatus for its manufacture, notably among which may IN mentioned the Tessie Gas Producer* described by Mr. A. L. Holley. A considerable experience by the author with producers of various kinds using anthracite fuel, in connection with the Taylor ore-roast ing furnace at Chester, N. J., with more or less unsatisfactory resnlts, finally led to the erection of the experimental producer described below, which combines in its construction, simplicity, dorability, and accessibility for cleaning and removing the ash and manipulating the fuel. It is adapted to the use of various kinds of fuel, and is capa ble of generating a steady and uniform supply of gas at a minimum cost. It has been in constant use day and night for about five months, and has given very satisfactory results. The producer, as shown in the accompanying sketch, consists of a cylindrieal furnace, preferably inclosed in an iron jacket or casing, having a bosh or inverted cone-shaped base as in a blast furnace. It is provided with a bell and hopper, the bell being hung to a forked lever, and having guide flanges to prevent it from swing ing, and an opening at its apex through which to insert a bar for manipulating the fuel, which when not in use is closed with a plug or stopper. Cleaning is effected through two small doors placed opposite each other at the hearth level, which in order to facilitate the operation is elevated above the floor. The doors are removable, and when closed are by their own weight and by means of bevelled lugs held tightly against their frames, forming a practically tight joint. A blast of commingled steam and air is injected into the fuel through a series of tuyeres underneath the bosh communicating with steam jet injectors. A small flue also connects the door

Jan 1, 1884

By A. W. Faheneald, Lewis S. Prater

By taking advantage of the fundamental difference between screening and classification—namely, that specific gravity has no effect on screening but is one of the important factors in classification—a combination of the two may be used as a process of mineral concentration. Although this fact is not new, so far as is known it has had little or no commercial application. The scheme is not presented now as a process for producing finished products but rather as a preliminary operation rejecting part of the barren material from an ore before it is subjected to more costly treatment. That is largely the function of the new heavy-media concentration processes that have been widely accepted. Original installation costs for the present sink-float processes are relatively high, however, which confines their use to operations where large tonnages are handled. Sink-float has been successful on only the relatively coarse (approximately plus 10-mesh) portion of an ore, and it is in this same range that classification screening can function most satisfactorily. Theoretically, there is no upper limit to the size of particles that can be handled in a sink-float operation, but the degree of liberation in the very large pieces usually limits this. With classification screening, particles from % to % in. would be the largest that could be handled, but the lower range could be extended somewhat below 10 mesh. In order to take full advantage of the difference in specific gravities of the minerals being separated, sorting in the classifier should be under as extreme hindered-settling conditions as possible. Laboratory tests have been made on a galena ore and on an artificial mixture of quartz and magnesite to determine the separations that may be expected. Although more than one scheme may be followed, in these tests the separations were made by cutting the underflow from the classifier as a concentrate and then screening the overflow. The screen oversize was rejected as a tailing. Classification was done in a hindered-settling teeter column and screening was done by hand, using the standard 4 2 series. The accompanying flowsheet gives the testing procedure followed.

Jan 1, 1947

By A. W. Fahrenwald, Lewis S. Prater

BY taking advantage of the fundamental difference between screening and classification-namely, that specific gravity has no effect on screening but is one of the important factors in classification-a combination of the two may be used as a process of mineral concentration. Although this fact is not new, so far as is known it has had little or no commercial application. The scheme is not presented now as a process for producing finished products but rather as a preliminary operation rejecting part of the barren material from an ore before it is subjected to more costly treatment. That is largely the function of the new heavy-media concentration processes that have been widely accepted. Original installation costs for the present sink-float processes are relatively high, however, which confines their use to operations where large tonnages are handled. Sink-float has been successful on only the relatively coarse (approximately plus 10-mesh) portion of an ore, and it is in this same range that classification screening can function most satisfactorily. Theoretically, there is no upper limit to the size of particles that can be handled in a sink-float operation, but the degree of liberation in the very large pieces usually limits this. With classification screening, particles from 3/8 to 1/2 in. would be the largest that could be handled, but the lower range could be extended somewhat below 10 mesh. In order to take full advantage of the difference in specific gravities of the minerals being separated, sorting in the classifier should be under as extreme hindered-settling conditions as possible. Laboratory tests have been made on a galena ore and on an artificial mixture of quartz and magnesite to determine the separations that may be expected. Although more than one scheme may be followed, in these tests the separations were made by cutting the underflow from the classifier as a concentrate and then screening the overflow. The screen oversize was rejected as a tailing. Classification was done in a hindered-settling teeter column and screening was done by hand, using the standard [v2]series. The accompanying flowsheet gives the testing procedure followed. [ ]

Jan 1, 1945

By Allan J. Clark, W. J. Sharwood

When the cyanide process came into general use, late in the nineteenth century, chlorination was quickly supplanted, but amalgamation yielded place more slowly, being still the major process at many plants, where it is followed by cyanidation of the tailings. The research work of the Denny brothers in South Africa' was probably the most important contribution of its time to the metallurgy of gold. By grading analyses of mill products, they pointed to the necessity of fine grinding to accomplish maximum extraction by cyanide. The work here described is merely an extension of the Dennys' method. Developing the fine-grinding principle, the steps of "crushing in solution" and of "all-sliming" were logical sequels, though both had been attempted early in the history of the cyanide process. Crushing in solution introduced certain complications in amalgamation; when "all-sliming " was adopted it was observed that the omission of amalgamation did not materially affect the total recovery. Thus the field of the older process has become much restricted, being at present confined to ores which, yielding freely to amalgamation, either are too low in grade to show an economic advantage in "all-sliming," or present chemical or other difficulties making the use of cyanide solution unadvisable during the crushing and preparation of the ore. South African ores are typical of the former class; Homestake ores are of both classes, but even in these instances the amalgamation work is being curtailed and greater burdens thrown on the cyanide plants. It is obvious that the time required for the dissolution of gold depends on the size of its particles. In an effort to determine the critical size, the following laboratory method was evolved. A standard amalgamation test2 had already been established, which involves the agitation of about 100 gm. of ore with 20 gm. of pure mercury, the latter then being separated and its gold contents determined. This method was applied directly to certain mill products with interesting results, a few of which may be noted here. The column "Free Gold" gives the value per ton thus amalgamated, as against the " Total Gold " determined by fire assay.

Jan 1, 1923

By Earl S. Greiner, Eric R. Jette

The constitution of the iron-rich iron-nickel-silicon alloys at 600ºC. has been determined by X-ray crystal structure methods. If the results are represented isothermally by a conventional equilateral triangular plot, the single-phase solid solution (body-centered cubic structure) of the iron-rich alloys at 600°C. is bounded by four two-phase areas. Three three-phase areas separate the respective two-phase areas. Three of the phases in the polyphase areas have the same structures as the corresponding phases in the binary iron-nickel or iron-silicon alloys. There are two phases, however, that have not been reported previously and whose structures have been tentatively identified in the present investigation. The solid solubility limit of the iron-rich solid solution at 600°C. was determined by comparing the lattice constants of this body-centered cubic phase in the single and polyphase areas. It has been shown that the lattice constants of ternary alloys may be represented by surfaces whose distances above the ternary plot (representing atomic composition) are proportional to the lattice constants of the respective alloys. Then the intersections of the surface for the single-phase alloys with those for the corresponding phase in the polyphase alloys, at the respective temperatures, are the solid solubility limits of the single-phase alloys at these temperatures. The data of the present investigation were evaluated by this method, although by a system of orthographic projection it was possible to represent the three-dimensional model in two-dimensional diagrams. This investigation has shown that the solid solubility of nickel in the body-centered cubic phase of the iron-rich iron-nickel-silicon alloys at 600°C. changes from 3.7 weight per cent (Owen and Sulley) in the binary iron-nickel alloys to 5.0 per cent in the ternary alloys containing 4.8 per cent silicon. Further additions of silicon increase the solid solubility limit of nickel to 16.0 per cent at 12.6 per cent silicon. From this point the limit decreases to 9.5 per cent nickel at 15.5 per cent silicon and is, of course, zero at 15.3 per cent silicon in the binary iron-silicon alloys.

Jan 1, 1943

This fund was established in 1929 for support of research and especially refers to non-ferrous mining and metallurgy. It is administered under the Board by a committee consisting of the President and Secretary and three members selected by the Board. HOWE MEMORIAL LECTURE The Howe Memorial Lecture, in memory of Henry Marion Howe, Past President of the Institute, was authorized in April, 1923, as an annual address to be delivered by invitation under the auspices of the Institute by an individual of recognized and outstanding attainment in the science and practice of iron and steel metallurgy or metallography, chosen by the Board of Directors upon recommendation of the Iron and Steel Division. The following were the Howe lectarers for the years indicated: Albert Sauveur—1924 Bradley Stoughton—1927 John A. Mathews—1925 Henry D. Hibbard—1928 William Campbell—1926 John Howe Hall.—1929 JOINT ACTIVITIES The Institute conducts jointly with the American Society of Civil Engineers, American Society of Mechanical Engineers, and American Institute of Electrical Engineers, certain activities as listed below, and is joint owner with them of certain properties. United Engineering Society This is a corporation organized by the American Institute of Mining Engineers, American Society of Mechanical Engineers, and the American lnstitute of Electrical Engineers, to hold the title and administer the property at 29 West 39th St. In 1916, the American Society of Civil Engineers was admitted, and each society now has an equal one-fourth interest in the ownership, occupancy, and administration of the building. . The cost of this property has been over two million dollars. A. I. M. E. representatives are: Arthur S. Dwight, John V. N. Dorr and H. A. Guess. Alfred U. Flinn, Secretary, 29 West 39th St., New York City. Engineering Foundation This is a fund established by the United Engineering Society in 1915 with a gift of $200,000 from Ambrose Swasey. Subsequent gifts had increased the fund to about $620,000 on March 1, 1929. The income of the fund is used to further research in science and engineering and to advance the profession of engineering and the good of mankind. A research project in alloys of iron is being conducted in

Jan 1, 1929

Charles Mather MacNeill, President of the Utah Copper CO. and of the Chino Copper Co., and a life member of the Institute since 1899, died at his home in New York on March 17, after a very brief illness with pneumonia. Mr. MacNeill was born at Oak Park, Ill., in 1871, and began his connection with mining enterprises immediately after graduating from high school, his first position being that of cashier with the Pueblo Smelting and Refining Co. He later went to Aspen, Colo., as manager of the Holden lixiviation plant. In 1893, he went to Cripple Creek as manager of the Lawrence Reduction Works, in which Mr. Holden and the late Capt. J. R. DeLamar were large owners. It was at this plant that Mr. Jackling became associated with him. The plant was destroyed by fire and, early in 1894, Mr. MacNeill became associated with Messrs. Spencer Penrose and Charles L. Tutt in a plan to finance and erect a chlorination plant at Colorado City, Colo., for the treatment of Cripple Creek ores. This plant was erected and was known as the Colorado-Philadelphia Reduction Works. Mr. MacNeill was general manager of the plant, Mr. Tutt having been president and Mr. Penrose, secretary and treasurer. The plant was very successful and was expanded, hally being reorganized under the name of the United States Reduction & Refining Company. Late in 1903, or very early in 1904, D. C. Jackling called the attention of Messrs. MacNeill and Penrose to the copper properties in Bingham Cañon, Utah, which have since become the main properties of the Utah Copper Co. After extended examinations and milling tests, these properties were bought, Mr. MacNeill becoming president of the Utah Copper Co., Mr. Penrose, secretary-treasurer, and Mr. Jackling, general manager. Mr. MacNeill remained president of the company to the time of his death. Mr. MacNeill was also a director, a member of the executive committee, and was largely interested in the Ray Consolidated Copper Co.; he was also president and a member of the executive committee of the Chino Copper Co. He had a variety of other mining interests, but the ones mentioned were distinctly the meost important. He was a director

Jan 1, 1923

THE strike of the coal miners began on April 1, as had been expected, the entire force of unionized miners-both anthracite and bituminous-going out and making this the most widespread strike of record. Up to the present writing there has been no serious inconvenience to industry in general, the accu-mulated stocks of coal being large and the non-union mines having continued to make a substantial production. However, the union labor leaders, having concentrated their efforts toward inducing the non-union miners to go out also, met with some measure of success in certain fields and created a shortage of coking coal, which caused iron makers to bank a few furnaces. The strike of textile workers in New England spread further. Here and there, throughout the country there were sporadic troubles with the builders. Rail-way labor was the subject of continued palavers, which did not get anywhere. On the whole the events of April were in line with the forecast that this would be a year of labor troubles. In domestic politics, the soldier bonus bill, having been passed by the House, went to committee consider-ation in the Senate. Public opposition to it manifestly waxed. On the floor of the Senate the tariff bill was under consideration and is drawing nigh to passage, without there being much consideration of its probable economic consequences. It is going to be a very high tariff and there is much in it that is equivalent to subsidizing small and normally unprofitable industries at the expense of the people as a whole. Abroad affairs were more quiet, superficially at least; than they were in March. In Egypt, India and South Africa things calmed, down, so far as we know, but in Ireland there was continued turmoil. The Irish, having won their freedom to the same degree as the Canadians, have entered upon violent quarrels among themselves, more over phrases than anything .else, so far as we can see. Lloyd George obtained a spectacular vote of confidence from Parliament and thus postponed, the exigency of a general election.

Jan 5, 1922

By R. E. Zimmerman

Wide attention is being placed upon various methods for cleaning the fine sizes of bituminous coals. The author describes and analyzes the results achieved on wet concentrating tables of modern design on unclassified feeds of —Vz in. particle sizes, including tests on high-sulphur coals. THE increased economic necessity of cleaning the small sizes of coal has forced wide attention upon various methods or processes being used. Although numerous cleaning plants in the past have been cleaning coal smaller than Vz or % in., the large quantities of higher ash fines being produced by mechanical mining and the need for cleaner coal under competitive market conditions have brought about many new installations of fine-coal cleaning plants. Of various methods used, one of the more popular types is the wet concentrating table. Approximately 525 tables have been installed in the United States in the past four years of which 320 have been installed in 20, large new plants. There are now probably 1600 tables of all types in existence in this country for cleaning coal. The purpose of this paper is to describe the cleaning of fine coal by wet concentrating tables. Its scope is confined to a discussion of the theory of tabling and some of the factors entering into tabling action, a description of the Deister SuperDuty diagonal-deck coal table and a discussion of the results of tabling various fine sizes of coals. Al- though tables have been used for cleaning coal as coarse as 2 in. and favorable results are reported, this paper is limited to reporting on the results of cleaning coal fines from 1/2 in. down. Also, although it is well known that the performance of tables is even superior under classified or closely sized feed conditions, this paper concerns itself with the results achieved by tabling unclassified feeds. History of Wet Concentrating Tables The wet concentration of minerals by some form of tabling is quite old, starting originally from fixed, smooth surfaced, tilted boards taking advantage of the laminar flow of liquid films and the separation of minerals according to specific gravity. This was followed by the development of rough deck surfaces

Jan 1, 1951

By C. R. Hocott

The distribution and movement of fluids in oil reservoirs are influenced to a great extent by capillary forces, which depend upon the size and shape of the pores in the reservoir rock, the surface characteristics of the rock, and the interfacial tension between the fluid phases. This paper presents the results of an investigation of the interfacial tension between salt water and crude oil containing dissolved gas under reservoir conditions. Apparatus and Procedure In the preliminary phases of this investigation, it was found that a scum formed at the oil-water interface, which made measurement of interfacial tension by either the ring or capillary rise methods unreliable. Accordingly, the drop-weight method, in which a fresh interface is continuously formed, was selected. In this method, a tip through which drops of one fluid can be expelled is immersed in a second fluid. At the instant that the drop becomes large enough to fall, the gravitational force tending to pull away the drop exactly balances the interfacial force tending to hold it. From the size of the drop, the dimensions of the tip, and the density of the two fluid phases, the interfacial tension may be calculated. The apparatus consists of a circulating pump for bringing the oil to equilibrium with gas at the desired pressure, a displacement pump for forming the drops, an interfacial tension cell in which the drops are formed, and a density cell to determine the density of the oil. The density of the water is determined separately in another apparatus. A flow diagram of the assembled equipment is shown in Fig. 1. The interfacial tension cell contains a stainless-steel dropping tip suspended from the top and extending below the surface of the oil. The tip is a cylindrical rod with a small hole in the center through which the water was forced to form the drop on the lower face. The walls of the tip were highly polished, to prevent the water on the tip from creeping up the side and increasing the effective diameter. The face of the tip, how-

Jan 1, 1939

By W. O. Hotchkiss

IN CONSIDERING the question of mining methods the possible rate of production deserves much more attention than it often receives. Hoover's theorem that, in order to show the greatest profit, an orebody should be worked out in the shortest practicable time, should be better known. The author recently' obtained detailed statements of costs from iron-mine superintendents of the Lake Superior district. In discussing these, the effect of rate of mining on cost of production was considered and detailed estimates were made. The methods by which these estimates were made and the way in which they were presented are here described to illustrate the importance of this factor in mining operations. The saving due to lower costs is not the only factor that should be considered. The greater profit per ton is of much importance but of equal importance are the greater profit per ton that will be made on a greater number of tons per year, and the fact that the total profit will be received in a shorter; period. This last makes a great difference in the present value of a property, by shortening the period of discount on future profits. Another item of importance to those operating a number of mines is that the tonnage needed to supply the market can be obtained most profitably by operating the smallest number of mines that will supply the amount required when each is worked to maximum capacity. In the Lake Superior iron district there are many grades of ore, and the requirements for each are known. If the demand for a certain grade can be supplied from mines now operating, the development and mining of a new orebody of the same grade must result in lower rates of production and lower profits to all mines producing this grade. If a company is mining the same grade of ore from three mines when it can supply its needs by operating only two, by operating only two it can obtain the greatest profit. Royalty rates, lease terms, and other considerations modify this general statement, but if all three properties

Jan 5, 1922

By C. K. Leith

MANGANESE is one of the minerals which is principally consumed in countries other than those of origin. Nearly 85 per cent of the pro-duction is used by the United States, England, Germany and France, and roughly a third of the total is used by the United States alone. On the other hand, over 85 per cent of the world production comes from Brazil, Russia, India, the Gold Coast of Africa, and the Sinai Peninsula. It follows from this fact that practically all manganese moves across international boundaries in raw or alloy form, and much the larger part of this movement is for considerable distances and is ocean borne. There is no indication that any one of the principal consuming countries can develop even approximately adequate supplies of its own. Under abnormal war conditions, with high prices and changes in metal-lurgical methods, only 35 per cent of the needs of the United States was met from local sources, and under our recent tariff only 11 per cent. There are thousands of manganese deposits scattered about the world, but only a very few which can figure largely in supplying requirements on a modern scale. The known reserves, together with highly probable extensions and explora-tions now under way, indicate no shortage from a world standpoint for many decades to come. The production and marketing of manganese is going steadily into fewer and stronger hands. The steel in-dustry uses over 90 per cent of all the manganese mined, and is acquiring control of a considerable part of the production in all of the principal fields-the Germans in Nikopol, the English in India and Gold Coast, the Americans in Georgia, India, Gold Coast and Brazil. Some of the controlling companies are of international scope. Concentration of commercial control is a notable tendency. A natural consequence is the growing un-easiness of smaller consumers the world over about their ultimate supplies and desire to know more definitely how and where manganese supplies will be controlled in the future. The sources of supply are few enough to warrant the belief that more or less monopolistic ele-ments of control are not impossible.

Jan 5, 1927

By R. V. Ramani, G. W. Luxbacher

The approach proposed in this paper is, as stated by the authors, an update of methods well discussed in the literature. The authors are to be congratulated for their excellent effort in quantifying a difficult problem with realistic cost data. Economic analysis of the components of a mine ventilation system is complicated by both the dynamic nature of the system and the uncertainty as to the time when system changes occur. We wish to address three specific areas of this paper which require further consideration: shaft designed air capacity, shaft location, and economic criteria used within the analysis. With regard to ventilation shaft size optimization, the system complexities are illustrated in the quantity flow through the shaft. Obviously, the capacity chosen by the designer is a static parameter while the utilized capacity is usually a dynamic variable over the life of the shaft. The designed capacity may be used for a short or a long period, and this may occur during the beginning, middle, or near the end of the shaft life, leading to different operating costs at different times. Operating costs, as shown by the authors' Eq. 8 are more dependent on air quantity than any other single factor (quantity cubed as compared with other factors to the single power); hence, extreme accuracy in the assessment of some of the other factors discussed by the authors may be secondary to the quantity estimation. Incorporation of a variable usage factor for air quantity over the life of the shaft in this optimization problem deserves some consideration. Although the authors have chosen to examine optimum ventilation shaft sizing, it must be remembered that optimization of the whole system-is the primary objective of any optimization process; unit optimization of such items as shafts may not complement the overall process. We have discussed this subject in some detail in another paper in this Transactions volume (Luxbacher and Ramani, 1979). While the recommended process by Wang, et al. can be used in shaft sizing, the shaft operating conditions (pressure head and air quantity) are intertwined with the shaft location within the mine infrastructure:

Jan 1, 1980

By Victor L. Stevens

The Oso tunnel is one of three tunnels located on the San Juan-Chama Project in south-central Colorado. The purpose of the tunnel is to carry water from the upper San Juan watershed through the Continental Divide into the Rio Grande watershed. The Oso tunnel contract was awarded by the U.S. Bureau of Reclamation to a joint venture of Boyles Brothers Drilling Co., Gibbons & Reed Co., and Cimco in February 1966. The Oso tunnel is 26,660 ft long and has a rock section of 10 ft, 2 in. with a lined diameter of 8 ft circular. The main portion of the rock formation was in the Lewis shale. This formation is quite consistent in hardness and texture with exception of localized limestone concretions and sandy siltstone inclusions. The job was bid on the basis of using a James S. Robbins mole of the P221 series. The decision for using a mole was predicated on the geology and the experience of the same joint venture on the adjoining Azotea tunnel where a mole was successfully used. The Robbins P221 series mole is capable of cutting from 9 ft, 11 in. to a 10 ft, 7 in. diam without any major change. It is 40 ft long and weighs 60 tons. The cutting head has 22 disk-type cutters and one center pilot (standard 9 7/8 -in.) tricone bit. The head is powered by four 75 hp electric motors. Gripper pads at about the midway point on each side of the machine are pushed into the tunnel ribs and thrust-cylinders in front of each gripper apply pressure to the face as the head rotates. The regripping cycle is 3 ft and then the grippers are retracted and advanced. Each cutter on the perimeter of the head is followed by a bucket which scoops up the cut material, almost in the same manner as a water wheel, and dumps it into a conveyor situated along the top of the mole. The muck from the mole conveyor is dumped into a gantry-type conveyor. The gantry conveyor is 350 ft long and is pulled

Jan 1, 1970

By Ralph Arnold

The lure of possible new oil fields shut off development of the older Montana fields during the year 1928, cutting down the total production to less than the 1927 mark. However, with the production of oil worth approximately $7,000,000 during the past 12 months, Montana oil producers pushed their total up to $44,000,000 taken from two principal fields during the past 8 years. The highest prices in the United States for oil of similar gravity gave northern Montana producers a decided advantage and brought up the value of the oil to about the same value as the 1927 production, although the oil runs were 1,000,000 bbl. less. Production by Fields The discovery of two new oil fields in the Sweetgrass Arch, in north central Montana, in 1927, diverted attention from the Kevin-Sunburst field. Many operators turned their attention to wildcats and practically all of the drilling contractors were called into the new Pondera and Bannatyne fields. Although discovered in 1927, the Pondera field developed its first commercial production in March of 1928. Mild interest was followed four months later by a rush of operators, and by August practically every string of tools had been moved from the Kevin-Sunburst field to Pondera. The fall months found 40 wells drilling in this field and as the year closed there were 100 producers. Pondera field is remarkable in that every well thus far drilled within the structure proper has been a producer. Dry holes have been drilled around the field, but none within an area of four sections. Experts estimate that Pondera will produce 5000 bbl, of oil to the acre. The producing area now outlined by wells drilled is expected to produce around 15,000,000 bbl. of oil. Pondera crude brings $1.75. This field has one pipe line and a second line is being laid. Lack of a pipe line delayed development of the new Bannatyne field, south of Pondera, and also in the Sweetgrass Arch. Bannatyne has 11 producing wells scattered over an area of approximately three sections. Bannatyne is a sand field with a 70-ft. sand in the lower Jurassic, which core-drill tests show to be 60 per cent. saturated. With the completion

Jan 1, 1929

By W. D. Bennett

AN interesting effect has been observed in the vacuum etching of titanium in the high temperature ß phase. Using a high vacuum annealing furnace, operating at less than 2x10-6 mm with a tubular titanium liner, it has been found possible to etch polished metallographic specimens at different temperatures between room temperature and 1000°C without contamination or increase in hardness.' Heat etching of titanium has been reported by other workers,' but the following example is of interest as an experiment under high vacuum in the absence of any contamination. Two polished specimens of iodide-processed titanium are placed at different positions along the axis of the furnace corresponding to temperatures of 900" and 800°C above and below the a-ß transus. The specimens are then raised to these temperatures and annealed simultaneously for 3 hr under the same high vacuum conditions. After cooling and withdrawing the specimens, their surfaces are photographed without further treatment. Figs. 1 and 2 show the results for the 800" and 900°C specimens, respectively. Fig. 1, corresponding to a vacuum etch in the a region, shows a typical equiaxed structure with what appears to be a slight shift of grain boundaries. Fig. 2, corresponding to a vacuum etch in the ß region, shows an equiaxed type of structure with the growth of striations in certain grains. The striations are only superficial, as a light polish and chemical etch restores the clean equiaxed structure. The vacuum etch, occurring as it does above the a-ß transus, records the state of the metal in the ß phase by means of the surface relief produced by the selective evaporation of metal from different grains; the metal itself reverts to the equiaxed a on cooling. The nature of the ß etch" (Fig. 2) suggests that, in transforming from the close-packed-hexagonal a to the body-centered-cubic ß lenticular-shaped laminae are formed parallel to common planes of the two structures. This would explain why some grains appear to be unaffected by the etch. The technique has interesting possibilities in the investigation of the mechanics of high temperature transformation. Acknowledgment This note is published by permission of the Deputy Minister, Dept. of Mines and Technical Surveys, Ottawa, Ont., Canada.

Jan 1, 1956