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By E. T. Turkdogan, J. H. Swisher

bi the fivst part of the paper results ave given on the rate of decarburization of Fe-C melts ln CO2-CO atmospheres at 1580°C. The rate -controlling step is believed to he that irvlloluing dissociation of curbotz dioxide on the suvfuce of the melt. 4 genevral reaction mechanistm is poslnlated jor gels-t11eta1 veactions oc-curit~g on the surface of iron coutcotamncited with chemi-sovbed osygesL. Oxygen the present work on decavbuvization of liquid iron and previous studies on the kinetics of nitrogen absorption and desorplion are discussed in terms of the postulated mechanism, ManY of the early studies of rate of decarburization of liquid steel were of an exploratory nature and laboratory exppriments carried out pertained to open-hearth or oxygen steelmaking processes. References to previous work on this subject may be found in a literature survey made by Ward. Using more sophisticated experimental techniques, several investigators have recently studied the kinetics of decarburization of molten Fe-C alloys in oxygen-bearing gases. For example, Baker et al2.' reported their findings on the rate of decarburization of liquid iron, levitated by an electromagnetic field, in carbon dioxide-carbon monoxide-helium atmospheres. In these levitation experiments the samples used were small in size, e.g., -0.6-cm-diam spheres weighing -0.7 g, and the rates were measured for decarburization from about 5 to 1 pct C at 1660°C. The rates obtained under their experimental conditions were considered to be controlled primarily by gaseous diffusion through the boundary layer at the surface of the levitated melt. Parlee and coworkers3 measured the rate of absorption of carbon monoxide in liquid iron. The rates were found to follow first-order reaction kinetics, yielding a reaction velocity or a mass transfer coefficient in the range 0.2 to 0.4 cm per min. The coefficient was found to decrease with increasing carbon content of the melt. These investigators attributed the observed rates to the transfer of carbon or oxygen through the diffusion boundary layer adjacent to the surface of the melt. In the work to be reported in this paper, an attempt has been made to study the kinetics of gas-metal surface reactions involved in the decarburization of liquid iron. EXPERIMENTAL The experiments consisted of melting 80-g samples from an Fe-1 pct C master alloy in an induction furnace and decarburizing in controlled CO2-CO mixtures at 1 atm pressure and 1580°C. The master alloy was prepared by adding graphite to electrolytic "Plastiron" melted in racuo. None of the impurities in the master alloy exceeded 0.005 pct. The reacting gases were dried by passage through columns of anhydrone; in addition, CO2 impurity in carbon monoxide was removed by passage through a column of ascarite. A schematic diagram of the apparatus is shown in Fig. 1. A 1.25-in.-diam recrys-tallized alumina crucible containing the sample was placed inside a 3-in.-diam quartz reaction tube, all of which was surrounded by an induction coil. A 450-kcps induction generator was used as the power source. Water-cooled brass flanges, which contained the gas inlet, gas exit, and sight port, were sealed to the top of the reaction tube with epoxy resin. The reacting gases were metered with capillary flowmeters and passed through a platinum wire-wound alumina preheating tube, 0.25 in. ID and 11 in. long. The gases were preheated to about 1300°C. A disappearing-filament optical pyrometer was used to measure the melt temperature. The pyrometer was initially calibrated against a Pt-6 pct Rh/Pt-30 pct Rh thermocouple. The temperature was controlled to within +10°C by manually adjusting the power input to the induction coil. In a typical experiment, an 80-g sample of the master alloy was melted in a CO2-CO atmosphere having pcO2/pco = 0.02 and flowing at 1 liter per min. A negligible amount of carbon was lost and no significant reduction of alumina from the crucible occurred during melting, e.g., 0.005 pct Al in the metal. After reaching the experimental temperature of 1580°C, the gas composition was changed to that desired for a particular series of decarburization experiments. The duration of the transient period for obtaining the desired gas composition at the surface of the melt was about 20 sec . The flow rate of the reacting gas was maintained at 1 liter per min. After a predetermined reaction time, the power to the furnace was turned off. During freezing, which took about 10 sec, the amount of gas evolution was not sufficient to result in a significant loss of carbon. The samples were analyzed for carbon by combustion and in a few cases they were analyzed for oxygen by the vacuum-fusion method. RESULTS A marked increase in the rate of decarburization of iron with increasing pcO2/pco ratio in the gas stream is demonstrated by the experimental results given in Figs. 2 and 3 for pco2/pco ratios from 0.033 to 4.0. In one series of experiments, denoted by filled triangles in Fig. 2, the reacting gas was diluted with argon (48 vol pct) resulting in a slower rate of decarburization. Samples from two series of experiments with pco2/pco = 0.033 and pco2/pco = 0.10 (with argon dilufion) were analyzed for oxygen. In these Samples the oxygen content increased with reaction time

Jan 1, 1968

By A. E. Nehrenberg

THE mechanism by which austenite forms in steels has received a great deal of attention in the literature in past years.'-'* Our present knowledge concerning this mechanism has been recently summarized quite concisely by Bain and Vilella,1 while a few years ago the literature was carefully reviewed by Roberts and Mehl.² The consensus is that any ferrite-carbide interface is a potential site for the nucleation of austenite during heating above the Acl temperature, and that the new austenite generally grows freely to produce approximately equiaxed grains, whether the carbides are initially present in the lamellar or the spheroidal form. In the case of eutectoid steels, growth of the new grains of austenite continues until contact is established with other grains. Then growth stops and an initial austenite grain size is established which does not change until the heating is continued to some high temperature at which grain coarsening begins. In the case of pearlitic steels which are not of eutectoid composition, the proeutectoid ferrite or carbide may interfere with the growth of the austenite if the temperature is not above that designated the A63 or the Acm, respectively. Although a large amount of work has been done to establish the mechanism of austenite formation in steels, it became clear to the present author while he was studying the transformation characteristics of a new 0.25 C Mn-Si-Ni-Mo hypoeutectoid steel" that the manner in which austenite grows in steels depends upon some factor, or factors, not previously considered. This was indicated by the fact that when this steel in the spheroidized condition was heated above the Ae1 temperature the new austenite which was formed did not envelop the carbides and grow in an equiaxed manner as described by Bain³ or spheroidized steels. Instead, in this steel, the austenite was observed to grow much more readily in certain directions than in others with the result that at temperatures within the Ac1-Ac³ ransformation range the austenite grains were acicular in shape. The excess ferrite was also found to be acicular with the distribution of these phases being such that a lamellar pattern was developed. This unusual directional growth of austenite in this new steel initially in the spheroidized condition is illustrated by fig. 1. A search of the literature revealed that this type of growth was not necessarily peculiar to this steel for similar microstructures had been observed by other investigators.4-8 However, the full significance of these microstructures does not appear to have been appreciated, and no work has been done to determine the conditions responsible for this directional growth of austenite or to arrive at an understanding of it. It was for this purpose that the work described in the present paper was carried out. Material: During the course of this investigation a total of 15 steels was studied. They consisted of hypoeutectoid, eutectoid and hypereutectoid carbon steels, and hypoeutectoid and hypereutectoid alloy steels, all of which were obtained in the annealed condition from commercial warehouse stock. As received, the carbon and alloy hypereutectoid steels had microstructures which consisted of spheroidal carbides in ferrite, whereas the eutectoid steel and the hypoeutectoid steels were pearlitic. The grades of steel represented were 1050, 1080, 10110, 3310, 4140, 4340, 4615, 6145, 8620, 9260, 9442,

Jan 1, 1951

(Under this heading will be published notes sent to the Secretary of the Institute by members or other persons introduced by members.) Mine Superintendent or Manager. Age 34, graduate mining engineer. Thirteen years' practical mining experience in Canada and United States holding responsible executive positions, mining engineer and mine superintendent. Experience in iron, gold, copper, and pyrite mining. Best references, can go anywhere but prefer location in Canada. At present engaged but desire change. Minimum salary $3600. A-2845. Manager or Superintendent for producing mine or new development. Institute member, 25 years' experience, mining, wet concentration, construction and examination. A-1173. Mining and Metallurgical Engineer. Technical graduate, 11 years' practical experience principally with copper mining, milling, smelting, and electrolytic refining, now holding an engineering executive position, wishes to change to place of more responsibility and opportunity. A-3785. Engineer with 11 years' experience in mining, civil, and industrial engineering, desires to become connected with a strong organization requiring services of thoroughly trained man. Graduated from University in 1909, now employed, having been with present organization nearly 7 years. Available about Sept. 15. A-4071. Metallurgical Engineer, age 31, married, A. M. and Ch. E.; 7 years' teaching and industrial experience, of which 3 ½ have been with electric furnaces. Desires position in investigative or executive work. Minimum salary $3000. A-4176.

Jan 9, 1919

[MINING AND EXPLORATION DIVISION Established as Mining, Geology and Geophysics Division, Sept. 27, 1949 Name changed February 19, 1958. Lyman H. Hart, Chairman Robert J. Lacy, Assistant Chairman Vice Chairmen: John C. Wangaard, Membership J. M. Ehrhorn, Program John G. Hall, Publications C. E. Nelson, Secretary American, Smelting and Refining Co. 120 Broadway New York 5, New York Editor, Rock-in-the-Box: J. W. Chandler.]

Jan 1, 1961

By Shigeki Nishimura

INTRODUCTION In this gapes, the author will describes to development of Yubari New coal mine. The construction set about since October 1970, and commenced from June 1975 in winning. Especially, descrives to compare with the studies at planning stage, and the experiences at under construction. The problems for development are next four: 1) There were no outcrop of the coal bearing strata, but the development was instituted against the deep coal seam occurrence at 800 m below the surface. 2) In order to the coal seams occured the deep level from the surface, threr had very difficult problems, i.e. temperature, earth pressure, methane etc. The countermeasure to solved them, were foundation of the development. 3) The construction was afflict with the inundation in high pressure, due to cement grouting and excavating alternately, overcame the difficulties. 4) The construction was finished by the encourage of national investment, in spite of the enterprise was weaken constitution from the energy revolution since 1960's. OUT LINE OF YUBARI NEW COAL MINE Geography Situation. Ishikari coal field is situated the west side of the Hidaka mountains, where runs north to south at center of Hokkaido, northern district of Japan. It's width is 40km in east and west, and length is 110km in north and south.

Jan 1, 1976

By John M. McAnerney

In 1955, the U.S. Army started to experiment in Greenland with tunneling in glacial ice and later in frozen glacial moraine. By 1960, long adits and experimental rooms had been successfully excavated. Full mechanization with coal-cutting machinery was most efficient in ice but drilling and blasting were necessary in bouldery moraine. In 1963, the U.S. Army Cold Regions Research and Engineering Laboratory, (USA CRREL; redesignated U.S. Army Terrestrial Sciences Center July 1, 1968) started a tunnel in the frozen silt of central Alaska near Fairbanks. The original adit of 360 ft (109 m) was successfully driven in the permafrost by a twin-rotor tunnel-boring machine, the Alkirk Cycle Miner. The workings were enlarged in 1966 and 1967 by standard mining techniques in which jackhammers, steam points, and augers were compared. A mechanical coal cutter was tried to supplement drilling and blasting. In 1968, airblasting techniques were used successfully for breaking out the frozen silt. All mine products were loaded mechanically and hauled by self-dumping shuttle car. Pneumatic methods of transport were tried for both dust removal and for conveying blast products up to 3-in. maximum size. Studies of the effects of natural winter ventilation through a shaft showed that tunnel closure could be reduced by lowering the adjacent ground temperature. It is concluded that underground openings in frozen ground should be cut and maintained at well below freezing temperatures to hold deformation to a minimum. HISTORICAL BACKGROUND This chapter deals with aspects of tunneling not previously discussed in the conference papers in this book. The chief differences are that the three tunnels lie entirely within frozen material and are relatively small, since they were constructed mainly for research. The primary objectives of the research were to develop underground shelters for military per-

Jan 1, 1970

By O. C. Wheeler

The slackening of activity in oil development in Colombia, which was noted in 1931, continued throughout 1932. In the producing fields output was further curtailed and active operations were substantially reduced. Exploratory work was at the lowest level reached in a good many years. Applications and Contracts for New Concessions The areas covered by the four applications accepted by the government in 1931 for concessions on national lands were not finally awarded the applicants, although the indications are that these will be granted during the coming year. iln application of Sr. Luciano Restrepo for a concession of 49,232 hectares located on the north side of the Sogamoso River in the Municipality of Bolivar, Department of Santander, was accepted by the Government toward the end of the year. The Government is expected to take action toward granting or denying this concession during 1933. The Richmond Petroleum Co. (Standard Oil Co. of California subsidiary) leased from Manuel Davila P. and Eduardo Villar a private tract known as the Fierro Arriba and Fierro Abajo lands located in the municipality of Victoria, Department of Caldas, near Honda. The terms of the lease provide for a cash rental and royalty. The company is allowed 10 years in which to start exploratory work. The lease covers a period of 15 years and is subject to renewal by periods of similar duration. Richmond Petroleum Co. The Richmond Petroleum Co. finally abandoned its Repelon No. 3 at 4312 ft., owing to drilling difficulties. No new hole was made on this well during the year. This was the only active drilling project in the country outside the Tropical Oil Company's concession, and with its abandonment all wildcat activities in the country ceased. South American Gulf Oil Co. This company did no drilling on its Colombian properties during the year. As in the preceding years, small amounts of oil, of no commercial

Jan 1, 1933

By T. F. Witherbee

In the sections, Figures 1, 2, and 3, are shown three crucibles that have been applied to substantially the same furnace, all the conditions having been the same except a variation of one foot of bosh, and a slight variation in the angle of the same. The bosh of No. 3 was originally the same as No. 2, the additional foot in diameter being the result of three months' cutting. Beginning with No. 1, which mas 5 feet 6 inches diameter, with tuyeres 5 feet 4 inches high, and cinder-tap four feet from bottom, great trouble was found in holding iron a proper length of time, four hours being the outside limit when working well, and two hours or less if working badly. "Break-outs" through the iron

Jan 1, 1880

By Joseph Bernhardt

THE Cornwall Ore Mines, Division of the Bethlehem Steel Co., at Cornwall, Lebanon County, consists of two separate magnetite ore bodies, approximately one mile apart. The one ore body was an outcrop in which open-pit mining operations were begun in 1742 and continued without interruption. This mine is also served by a shaft for mining that portion of the ore body not recoverable by open-pit methods. The other property had no outcropping and is entirely an underground operation. This mine, cap-tioned No. 4 mine, is serviced by two shafts 220 ft apart. The No. 4 shaft is for hoisting rock and ore, and the No. 5 shaft is for handling men and ma- terials. The shafts are on a catenary curve, closely following the dip of the ore body. Slope of the shafts at the collar is 36", flattening to 26" at the bottom. The footwall at Cornwall is a traprock which varies structurally from solid to highly fractured. Grizzly stations at the top of each chute raise were reinforced by setting timber sills on concrete. Occasionally it was necessary to concrete the entire chute raise. Concreting was done by using 35-yd electric mixers set up in the breaking subs. Sand, stone, and cement were hoisted up through the chute raises to the breaking subs. Late in 1937 it was decided to eliminate chute raises and breaking subs in future development. Haulage levels are 50 ft apart vertically. When ore is below a 40 " dip, slushing drifts are driven normal to the haulages and on 40-ft centers. In a few areas, ore dips greater than 40" and slushing drifts are then placed parallel to the haulage drifts. Finger raises are opposite each other and on 20-ft centers making 20x20-ft draw areas (fig. 1). For loading

Jan 1, 1951

By Alan U. Seybolt

In examination of some cold-rolled copper and cupronickel that contained a little columbium, it was discovered that these alloys were unusually resistant to annealing. This effect was suficiently pronounced to warrant some investigation of the annealing characteristics of such compositions. Experimental Procedure The alloys were made from cathode copper, electrolytic nickel, and a special copper-columbium hardener alloy furnished by the Electro Metallurgical Corporation. This hardener alloy contained 10 per cent columbium, with tantalum, aluminum and iron as major impurities. The melting was carried out in a clay-graphite crucible in a high-frequency induction furnace! under a charcoal or electrode carbon cover. No deoxidizing additions were made. The 7-lb. copper heats were poured into a steel mold, hot-rolled to 1/4-in. thickness, and annealed for 56 hr. at 760°C.; the cupronickels were annealed I hr. at 815°C. The material was then cold-rolled to a 50 per cent reduction in thickness and annealing tests were carried out on this 1/8-in. hard-rolled strip. A little silver was added to copper-columbium alloys 402 and 403 to find out

Jan 1, 1942

Jan 1, 1915

By F. W. Maclennan

ORE production from the property of the Miami Copper Co. began early in 1911. Until 1925 this ore came from the so-called high-grade orebodies, which contained a little over 2 per cent. copper. This ore was mined by the following methods. 1. Top slicing after mining the peaks by square setting, which produced 4,524,347 tons, including ore from square setting. 2. Shrinkage stoping with sublevel caving of the pillars, which produced 2,230,577 tons. 3. Undercut caving with hand tramming, which, produced 15,427,672 tons. Estimating December tonnage, the total ore mined to the end of 1929 will amount to slightly more than 43,000,000 tons. The first method was described by E. G. Deane1 and the second by D. B. Scott,1 and the third, together with a general, description of the mine, by J. H. Hensley, Jr.1 The geology of the district has been worked out by. Dr. F. L. Ransome.2

Jan 1, 1930

By E. W. Lithgow, E. G. Williams, R. R. Holbrook, B. R. Wilson

The mineralogy and geochemistry of Pennsylvanian shales and underclays were studied to determine their suitability for lightweight aggregate and refractory ladle brick. Eighty percent of the variation in bloating of shales and clays was explained by the variation of Si02, A1203, and fluxes (Fe203, MgO, CaO, Na20, and K20); 60% by variation in quartz, kaolinite, illite, and chlorite. The best bloating was exhibited by marine shales, whereas freshwater shales and underclays experienced little or no expansion. Regional paleogeographic maps o f Pottsville and Allegheny shales permit bloating to be geographically predicted. It was found that clays meeting the specifications for refractory ladle bricks were obtained from underclays having over 34.5% mica, over 40% kaolinite and less than 15% quartz. Underclays of this composition are confined to the lower Allegheney outcropping along the near-margins of the coal basin. The best clay is that underlying the Lower Kittanning coal. Porosity of the first fired brick was found to be inversely correlated with reheat expansion.

Jan 1, 1975

By E. A. Koester

Kansas produced approximately 35,434,000 bbl. of oil in 1932 compared to 37,018,000 bbl. in 1931, a decrease of 1,584,000 bbl. or 4.2 per cent. These figures do not indicate the amount of oil that could have been made available from the state for the year. Many of the fields discovered during the year and some discovered in previous years were entirely shut in. Practically all flush production discovered within the last two years has been prorated in some manner or other. Probation Kansas production is under regulation as specified in House Bill 387, passed by the legislature in 1931, which became effective when published May 28, 1931. The principal features of the law are the prohibition of waste, including gas energy, the regulation and prevention of discrimination of purchasers, the marketing of oil ratably from wells in each field when the daily production is above 15 bbl. per well. This act gives the enforcing powers to the Public Service Commission. The Commission, having many other regulatory duties, appointed an Oil Advisory Committee, which, with the aid of the State Umpire, keeps records and makes recommendation for orders as to specific regulation of fields and conditions in each field. At the time the Commission was given authority to regulate production and marketing in flush fields, several of these had already been under voluntary proration and marketing restrictions by agreement of the operators. These gradually came under the control of the Commission by mutual consent. It is the policy of the Public Service Commission to follow the will of the operators so long as they do not have ideas or plans in conflict with the law. The cost of administration of this law is assessed against the operators according to the amount of oil taken from the fields in which ratable taking is necessary. There is a feeling that the whole state should share this expense, which is small, since it is beneficial to the older fields by assuring them 100 per cent market for their output by restricting the flush fields.

Jan 1, 1933

By William P. Blake

THE use of diamonds upon a large scale in drilling rocks, and the substitution to a certain degree of rotary diamond drills for the ordinary steel percussion drills, marks a new era in the art of mining. Since the invention by Leschot of the diamond drill, it has steadily advanced in its utility and range of application, and in the appreciation of miners and engineers. I t must be claimed as one of the many gifts of science to the arts ; and it is, in particular, one of the fruits of the scientific education given at the Ecole Centrale, at Paris. Members are all, doubtless, more or less familiar with the construction of the drill and of the machinery by which it is applied in boring. I t is, therefore, my present purpose only to direct your attention to some recent marked improvements, made by the American Diamond Drill Company, by which the economy and efficiency of the machines have been increased. Form of Bit.-The annular or ring form of the drill-head or bit was, I believe, the earliest; and it is still in use, without essential modification, wherever it is desired to obtain a sample " core" or specimen of the rock traversed. But for mere drilling, regardless ~f the preservation of a test-core, a solid-head bit is preferred, except for very large holes. Until recently, these solid-head bits were made with a pointed cutting face shaped like an obtuse cone. This form was assumed to be the best, being most in accordance with the experience obtained with percussion drills. I t is found, however, that the exact reverse

Correlation between Metallography and Mechanical Testing By H F MOORE (Henry Marion Howe Memorial Lecture Trans, vol 120 11,000 words ) The lack of effective correlation between metallography and mechanical testing from the days of Reaumur to the present is noted, and two general problems of such cor¬relation are stated (1) the correlation of qualitative test results with quantitative, and (2) the correlation of average results with maximum or minimum results Some correlation has been achieved, notably in the field of heat-treatment and in the study of elastic strength of metals Correlation is in the process of being developed in several other fields, including the quantitative study of the effect of grain size of metal on mechanical properties, of grain size and type of crystalline structure on the sensitivity of metals to weakening at holes, notches and other "stress raisers," and in the study of the starting phases of spreading, "fatigue" cracks Correlation of mechanical test results and metallographic study is needed in the study of such problems as the various theories of failure of metals, the meaning of and tests for service ductility of metals, and the relative damaging effect of defects inherent in metals, such as minute cracks and segregation, as compared with the damaging effect of "imposed" stress raisers, such as screw threads, sharp shoulders, etc The neces¬sity for more correlation of metallography and mechanical testing during student days is emphasized, and also the need of a better understanding on the part of engi¬neers of the significance and limitations of metallographic apparatus and results and of X-ray diffraction This should be matched by a better understanding on the part of metallurgists of the significance and limitations of mechanical tests of metals, of testing machines and strain-measuring apparatus

Jan 1, 1937

By Theodore B. Comstock

Prior to 1885, the College of Engineering in the State University was under the care of such professors and instructors as were required for efficient work in the Schools of Mechanical Engineering, Civil Engineering and Architecture. The development of the coal and other important mineral resources of the commonwealth led gradually to a considerable demand for instruction in the branches more closely related to mining engineering, and a very creditable effort was made to meet this want by arranging special work in the field and in the laboratory for students of mining and metallurgy. This plan, while it gave much added labor to several already heavily taxed professors, caused such students to become something like undesirable excrescences upon the regular courses. But its partial success gave abundant proof of the real necessity for a complete course in Mining Engineering. The famous Braidwood disaster emphasized anew the importance of thorough training on the part of those to whom the responsible duties of mining must be confided. As is well known, a very excellent beginning was made some years ago by the Legislature in the matters of inspection and regulation by the enactment of a reasonably effective law, which was afterward much improved.* About the date of the last Acts, it was deemed wise to enlarge the facilities at the University arid to furnish adequate training for the increasing number of applicants. Accordingly, in August, 1885, the writer was requested to assume the duties of the professorship, it being the expressed desire of the Board of Trustees and the Regent of the University that a School of Mining Engineering should be founded which might eventually come to rank with the other engineering schools already flourishing here. It is the main object of this paper to state plainly the steps thus

Jan 1, 1887

By Dwight E. Woodbridge

DuriNg April, Max, and June, 1910, I was in charge of an examination of the greater part of the Moa iron-ore area in Oriente Province, Cuba, on the north coast, near the east end of the island. My instructions, on arrival at the properties, were to check former estimates of tonnages and grades, and to re-examine the ore comprised in claims covering 44,727 acres. This work included the running of lines dividing the properties into co-ordinate planes, the boring of many thousand feet of holes spaced at the intersections of these co-ordinates, the taking of samples of the ore penetrated, the analysis of these samples for their various constituent minerals, and the determination of the results as to tonnages, depths, and grades, both for individual properties and for the entire group. Each section of every one of the thousand holes drilled was to be compensated for depth and grade with every other, a series of simple arithmetical calculations of no slight magnitude, the mere mechanical labor of which consumed much time, but finally resulted in giving a complete average of all the essential facts for the entire area of 18,000 hectares, Had it not been for the more than willing, active, and able co-operation of the officers of the Spanish-American Iron Co., from Charles F. Rand, President, and Jennings S. Cox, General .Manager, down to the most humble water-carrier, the work would have consumed far more time than it did. The lands thus systematically explored by me were comprised in the following denouncements: Punta Gorda, Yaminiguey, Baracoa secunda, Sagua, Moa, Yajrumaje, Lirio, and Cabanas, all of which were massed as the Moa group, so called, and cover an area of 13,832 hectares, or 34,179 acres. Some 10,000 acres additional to this was included in neighboring properties, lying between Moa and the east end of the island, the Buena Vista,

Jan 1, 1912

By I. Nilsson, G. Sundkvist, A. Danielsson

A spectrochemical method of slag analysis is descibed which utilizes fusion of the sample with a flux, then cooling and crushing to put all samples into a common form. The powder, is then fed onto adhesive tape and passed through a spark by means of a special device to provide very reproducible discharge conditions. Combined with a direct-reading optical emission instrument, this system provides speed and accuracy of antilysis heretofore unobtainable for. slag samples by any other method. THERE are many suggested methods for spectro-chemical analysis of slags. The most important are fusion-pellet methods and solution methods. In our company the fusion-pellet method has been used earlier, and is described by Lounamaa. W. H. Tingle and C. K. Matocha have made refinements of the pellet method.' A Committee of the British Iron and Steel Research Association has investigated different methods of spectrochemical analysis of slags. Its purpose was to formulate a method which would give the complete analysis in 30 min with an accuracy of ±3 pct. The committee recommends a solution technique, which was thought to correspond best to their requirements. The method to be described is a fusion-tape method. The sample is isoformed by fusion and grinding. The powder is analyzed with the tape technique. The tape machine and some of its applications are described earlier.4'5 The powder to be analyzed is continuously fed onto a moving adhesive tape, which passes through the spark gap. The sparks break through the tape and vaporize and excite the material to be analyzed. The most outstanding feature of the tape machine is its very high reproducibility. The concept of isoformation has been introduced earlier.= It means a pretreatment of the samples to make them uniform from the spectralanalytical point of view, i.e., cancelling systematic differences between the samples. The purpose of the isoformation is to reduce the influence of particle size, as well as chemical and mineral composition. Before describing the isoformation by fusion plus grinding, which is the purpose of this paper, a few words will be said about two other types of isoformations, i.e., grinding with buffer and ion exchange plus grinding as they have been considered during the application of the tape technique for slag analysis. Grinding with buffer might be a sufficient isoformation in some special cases, where the mineral composition is defined. The time of grinding must, however, be rather long, at least 5 to 10 min, even when using such an efficient mill as the Swing Mill from Messrs. Siebtechnik, Mühlheim, Germany. This type of isoformation is not recommended due to its limitations and due to the fact that the gain in time compared with the fusion technique is almost negligible. The principle of ion exchange plus grinding and some of its applications have been described.5 The following elements of interest in slag analysis can be determined in this way: Na, K, Cu, Mg, Ca, Ba, Zn, Pb, Al, Cr, Mn, Fe, Co, Ni. The very important element Si, however, cannot be analyzed with this method. Although the ion exchange isoformation for slag analysis cannot be looked upon as a routine method, it can be used for

Jan 1, 1962

By Ancel St. John

During a session on coal and coke at the February, 1926, meeting of the American Institute of Mining and Metallurgical Engineers, the writer called attention to the important work on the X-ray analysis of coal1,2 being carried on in England by C. Norman Kemp and his associates. This aroused so much interest that a paper on the subject was requested for the October meeting. It has seemed advisable to make this paper a preliminary survey of the present status in the application of X-ray methods to coal problems and to follow it from time to time with further articles as the art develops. A survey of this sort naturally divides itself into two parts, radio-scopic analysis of the distribution of constituents through the body of the coal, and diffraction analysis of the state of association of the elementary components. In this article the subject matter concerning radioscopic analysis has been drawn almost entirely from the writings of Kemp and his associates and the illustrations have been sptcially furnished by him. It is a pleasure to record here a great indebtedness for this courtesy and cooperation. The subject matter and illustrations concerning diffraction analysis are taken from the author's unpublished researches. Nature and Properties of X-rays Before proceeding it is well to recall the nature and some of the properties of X-rays, as well as our present conception of atomic structure According to the accepted theory atoms are composed of electrically-charged particles. A positively-charged center, called the nucleus,

Jan 1, 1927