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By Alden B. Greninger, Alexander R. Troiano

The crystallographic mechanism for the austenite-to-martensite trensformation has been deduced from the results of the following new experimental determinations: (I) the accurate evaluation of the lattice relationship between austenite and individual crystals of martensite—and thus the relationship between the martensite lattice and the martensite plate, and (2) the measurement and analysis of the change in positions that a volume of austenite unclergoes when it transforms into a crystal of martensite. For the latter study, a new tool was developed, the stereographic analysis of shear. Lattice relationship.—Thirty-five separate 50-gram melts of an alloy containing about 22 per cent nickel and 0.8 per cent carbon were prepared in a high-vacuum furnace. This alloy is all-austenite at room temperature; grain size was about I cm. Specimens of the alloy were cooled to about — 70°C. to form a few martensite crystals, and suitable specimens were ground and polished on a surface parallel to a single martensite plate, exposing the martensite crystal for an area of 1 mm. or more. Four martensite cystals from four diffierent ingots were prepared in this manner; the largest crystal of this group is illuslratecl in Fig. I. Back-reflection Laue patterns were obtained from martensite crystals (and the matrix austenite) both before and after tempering. The locations of the basal-plane pole of martensite was checked by means of oscillating crystal X-ray patterns. All four crystals studied yielded the same solution ( ± 0.5°), and these relationships are expressed in gnomonic projection in Fig. 3.* The narrow dark-etching bands often visible in martensite "needles" were found to be parallel to (112) and thus are undoubtedly twin bands in the martensite crystal.

Jan 1, 1941

By Wm. Hamilton Merritt

With the exception of the Vancouver Island coal, all the western coal-fields owe their present development to the completion, in the autumn of 1886, of the Canadian Pacific railroad. While it could not be expected that a very great deal could be accomplished in three years, enough has been done to pretty thoroughly establish the coal-bearing areas and their correspondence with those which have been developed to the south of the boundary along the lines of the transatlantic railroads in the United States. This summer I visited some of the important developments in the coal areas of Washington Territory, largely with the object of being better able to appreciate the corresponding coal-bearing areas in British Columbia to the north. In Western Canada, coal-bearing rocks have been found in three zones: 1. In the plains to the east of the Rocky Mountains and in the eastern flanking ranges, the coal occurs in the Cretaceous formation (including the Laramie). 2. In the interior plateau of British Columbia, the coal is found in the Tertiary formation. 3. On the coast of British Columbia, Cretaceous and Tertiary rocks are found carrying coal, and on the Island of Vancouver the well known Nanaimo coal has been worked for years in the first named formation. In all of these zones, the coals vary from lignites up to higher grades, the factor determining quality being the amount of pressute to which they have been subjected. The intensity of this pressure is generally shown by the disturbance which the coals exhibit, and, in many cases, is almost directly in proportion to the distance of the deposits from mountain ranges. This seems to be also the opinion expressed by Mr. Bailey Willis in connection with his Census Report on the coals of Washington. It has been elsewhere stated

Jan 1, 1890

By J. E. Hanlon, J. D. Wolf

The relaxation peaks observed in plastically deformed materials at low temperatures have been reviewed by sack1 and Niblett and wilks. 2 In particular, the dislocation-relaxation in columbium has received considerable study.3-6 The present work deals with the lower-temperature dislocation-relaxation peak (referred to by Chambers and Schultz as the a peak) in columbium and Cb-5 pct Zr. The columbium and Cb-5 pct Zr specimens were machined to 3/8-in.-diam by 7-in.-long rods from bars hot-extruded at 1200°C. The internal friction and resonant frequency of the samples were measured in torsion at kilocycle frequencies at a maximum strain amplitude of -10-6. The interstitial content of both materials was approximately 70 ppm N and 200 ppm 0. The dislocation-re laxation peaks were measured in the hot-extruded state and after successive anneals. Fig. 1 is a compilation of the data. The resonant frequencies for the columbium and Cb-5 pct Zr samples were, respectively, 5.5 and 6.5 kc. Other workers have noted that the dislocation-relaxation peaks in columbium are not characteristic of a single relaxation time. As can be seen in Fig. 1, the zirconium addition further broadens the spectrum of relaxation times. The magnitude of the modulus defect as computed from resonant-frequency data also reflects this extension. The occurrence of the low-temperature a peak at a position 20°K higher in Cb-5 pct Zr as compared to pure columbium, in the hot-swaged state, suggests a decrease in the average dislocation mobility for the alloy. The authors do not feel that these data are sufficient to permit an interpretation in terms of any detailed models.

Jan 1, 1967

By F. A. Forward, A. H. Ross, J. Halpern

IN treating carnotite ores by carbonate leaching it is often necessary to subject the ore to a prior roast. Among the advantages that may result from roasting are: 1) improvement in settling and filtering characteristics of the ore; 2) destruction of carbonaceous impurities that would otherwise contaminate the leach solution and consume carbonate reagent; and 3) substantial increase in extraction of vanadium, which is usually low when the un- roasted ore is leached. Recovery of vanadium may be an important factor in processing carnotite ores, and the fact that vanadium is usually recovered in good yield by acid leaching has often been an economic advantage over results obtained with carbonate leaching. It has been found that response of an ore to carbonate leaching, following roasting, depends primarily on its composition and on the conditions of the prior roast treatment, particularly with regard to the roasting temperature, the atmosphere maintained above the charge during roasting and cooling, and the presence of certain reagents. These factors, especially the last, virtually determine the extractions of uranium and vanadium attainable by carbonate leaching, as well as the reagent consumption on leaching, whereas adjustment of the leaching conditions has only a limited influence.

Jan 10, 1957

By Peter L. Langsjoen, Kenneth L. Maloney

Ten small and intermediate-sized (4.5 Mg/hr to 113 Mg/hr steam--10,000 to 250,000 lb per hr) coal-fired boilers in the upper Midwest have each been tested on both a bituminous eastern coal and a subbituminous western coal. The purpose of this study was to determine the feasibility of substituting western subbituminous coal for eastern bituminous coal as a means of reducing the SO, emissions from this class of boiler and to demonstrate the feasibility of greatly expanded western coal utilization as a means of reducing the use of oil and gas. The scope of this study was such that the representative boiler types were tested on both eastern and western coal for a period of time sufficient to completely characterize their individual emission and operational characteristics.

Jan 1, 1978

By Eckley B. Coxe

(WITH FIGURES ON PLATES II, III, AND IV.) I DESIRE to call the attention of the Institute to two deep vertical shafts, which are now being sunk in Schuylkill County, Pennsyl¬vania, about 1 1/2 miles north of Pottsville. These shafts are of interest to the mining engineer, not only on account of the novelty of the method of sinking adopted, which promises to produce a revolution in that branch of mining engineering, but also as examples of the manner in which such work should be undertaken. GEOLOGICAL SKETCH OF THE TERRITORY TO BE WORKED BY THE SHAFTS AND REASON FOR SINKING THEM. The Mammoth or E Vein of the anthracite coal-measures in that part of the Schuylkill region near and north of the town of Pottsville lies at a great depth below the surface, and has, in consequence, never been worked in that locality.

Jan 1, 1873

By E. G. Davis, G. V. Sullivan, J. P. Hansen

As part of its overall goal to maintain an adequate supply of minerals to meet national economic and strategic needs, the Bureau of Mines, U.S. Department of the Interior, investigated the feasibility of producing subsieve-size material by an attrition grinding method. The Bureau-patented technique employed intense agitation of a mixture of the material to be ground, a granular grinding media, and a suspending fluid. A variety of materials were successfully ground to extremely fine particle sizes. Studies were made to determine the method's efficiency in grinding industrial minerals and metals to minus 2 micrometers and ceramic powders to an average particle size of 500 angstroms. Transfer of this technology to a commercial scale has been achieved. Commercial-scale units are currently being used in the paper-coating clay and titania pigment industries.

Jan 1, 1980

By R. B. Sudderth, C. R. Merigold

Greater, emphasis is being placed on recovering nickel from laterite ores by ammonia leaching techniques. New methods are required for lower cost, non-polluting techniques to separate more efficiently the metals of interest. Liquid ion exchange techniques meet these requirements with the added advantage of producing salable electrowon nickel cathodes at the plantsite. A complete solvent extraction- electrowinning process is described, including preliminary engineering and cost data for a typical plant producing 50 million pounds of nickel per year.

Jan 1, 1973

By S. W. Parr

STUDIES relating to the behavior of coal toward oxygen may have for their purpose the determination of the fundamental factors that underlie spontaneous combustion, weathering and deterioration, and the general topic of storage, as well as those properties that have to do with the underlying principles of carbonization. There is also involved the possibility of developing information relating to the constitution of coal, or at least the chemical properties inherent in the type substances of which the coal is composed. It is the purpose here to record certain FIG. 1. results bearing on this latter idea of the chemical properties that characterize the main constituents of bituminous coal. The avidity of freshly mined coal for oxygen has long been known. What happens to the coal or to the oxygen is not so clear. Is the oxygen absorbed or chemically combined, and what are the conditions as to time, temperature, texture, or components that are most involved in the phenomenon?

Jan 6, 1925

By Louis B. Slichter

Prospecting is certainly the world's biggest and best gambling business. It is a game where the chips cost many thousands and where many millions, even billions, can be won. An attractive feature of this gamble is the fact that the players are free to rig the odds as favorably as possible. Only the limited bounty of nature, the restrictions of the laws of the land, the competition from other players, the limited sagacity of the player himself- only these, and other factors, restrict the possibilities for large winnings. Today probably about half the land surface of the earth remains to be searched for signs of ore visible at the surface. It is fortunate that so much land still remains for exploration by relatively economical methods. Looking to the future, it is a good guess that the costs of finding ore will increase in response to increasing technical difficulties. To continue to achieve profits from prospecting, it will become necessary to analyze the business more skillfully, in a more and more sophisticated manner. Whenever feasible, qualitative concepts must be replaced by their quantitative equivalents, improvements, and extensions.

Jan 6, 1960

By D. L. Harris, A. M. Gaudin

THE following results, presented here in condensed form,1 were obtained in a preliminary study of the adsorption of n-hexane thiol, hexyl mercaptan, on sphalerite, zincite, willemite, and quartz, from aqueous solution and from a gas. Interest in this subject was aroused by a Belgian report2 of effective use of hexyl mercaptan for flotation collection of oxidized zinc minerals. The relatively low boiling point, 149°C, of the mercaptan3 suggested the desirability of extending the usual measurements of partition of collector between aqueous solution and gas and between gas and mineral. It is believed that this paper presents the first measurements of this type on a flotation system. Attempts were made to carry out the measurements at equilibrium, but as the work progressed it became increasingly doubtful that this desirable condition had been achieved. To control composition and extent of the gas phase, the apparatus was a wholly-enclosed thermally-controlled glass system. Because of these constraints and the desirability of dealing with pure minerals, a scale of operations was chosen in which a few grams of deslimed mineral were used in each test. It was also necessary to choose a particularly sensitive method for mercaptan analysis, and in fact a method that would permit the experimenters to follow the approach to equilibrium. For these reasons mercaptan marked by radiosulphur 35 was used. An analysis was made for the radiosulphur by a modification of the method of Gaudin and Carr.4

Jan 9, 1954

By Shiou-Chuan Sun

THE effects of oxidation on the flotation behavior of sulphide minerals have been extensively studied,1-3 but no similar study has been made of coals. Coals of bituminous and lower rank undergo atmospheric oxidation during mining and storage, and their degree of oxidizing increases with temperature4,5 and time of exposure.6 The problem of recovering fine oxidized coal from culm piles, rivers, and streams by froth flotation has become increasingly important to the coal industry as well as to those concerned with air and stream pollution. This paper describes the flotation behavior of oxidized and unoxidized coals and carbons in the presence of oily collectors and presents the reagents found effective in the flotation of oxidized coals and carbons. Except where otherwise stated, flotation tests were performed in a 50-g Denver flotation cell. Solid feed for each test was 30 g, and the pulp dilution was kept at 8.5. The -65 mesh coal sample was wetted by agitation with water in the flotation cell for 6 min, then conditioned with a predetermined amount of collector for 2 min, and finally floated with pine oil as frother for 3 min.

Jan 4, 1954

By A. L. Field

Bureau of Mines Technical Paper 189 consists of a record of the scientific data obtained in the iron blast-furnace slag investigation which is reported in Technical Paper 187, "Slag Viscosity Tables for Blast-Furnace Work." It includes a description of the method of preparing the synthetic melts, construction of an improved electric furnace, and refinements in laboratory methods of measurement. Only the general features of the work and the conclusions drawn from the experimental data can be given attention here. Silicates in the Liquid State In the manufacture of refractories, Portland cement, glass, and porcelain, and in pyrometallurgical operations, importance attaches to the behavior of silicate compounds at temperatures beyond the range of common experience. This field of research has not been investigated as carefully as its scientific and industrial importance would seem to warrant. Probably the most important of the unsolved problems in the, chemistry of silicates is the question of their stability in the liquid state. That little progress toward the solution of this problem has been made is not strange if there be borne in mind the difficulties attending experiments made at temperatures at which silicates become fluid, and the comparatively short time since it became possible to measure these temperatures. On the other hand, considerable progress has been made in the study of the compounds in the solid state because of the directness and simplicity of methods of optical examination.

Jan 12, 1917

By M. E. Learmont, I. Iwasaki

Grinding with steel media adversely affects the flotation response of galena. Electrochemical measurements, flotation tests, and AES, XPS, and STEM examinations were employed to identify interactions between galena and mild steel. Iron oxide, hydroxide, or sulfate species that formed on the galena surface upon contact with mild steel decreased its floatability, with the time of contact and aeration condition affecting the severity of the flotation depression. Parallel tests performed with an active metal, magnesium, indicated that floatability was also affected by the presence of a surface coating involving lead species.

Jan 1, 1985

By K. U. Snowden, J. N. Greenwood

CRACKS which form in lead exposed to fluctuating stress frequently follow a rectangular pattern. It is well known that under ordinary atmospheric conditions these cracks are intercrystalline. On the other hand after fabrication the crystal grains in lead are in general irregular polygons. The observed facts appear to be mutually contradictory. Re-examination of some lead failures has confirmed that the rectangular cracks are intercrystal- line. It follows therefore that under fluctuating stress some of the grains lose their irregular outlines and become approximately regular polygons of cubic type. G. R. Gohn and W. C. Ellis* suggest that this is due to recrystallization during the life of the part, in such a way that the new grain boundaries are aligned at 45 deg to the longitudinal strain prior to the formation of the fatigue crack. Experiments at Baillieu Laboratory—Some recent experiments carried out in the Baillieu Laboratory in conjunction with the Broken Hill Associated Smelters have thrown some light on this transition. A test piece of pure lead was polished chemically

Jan 1, 1959

By Luke L. Y. Chang, Bert Phillips

A number of molybdenum oxides have been synthesized and their crystal structures have been described.' No data have been published on the stabilities of these oxides nor on the phase relations in the system Mo-0. It is probable that the tendency toward oxidation of both the metal and the oxides with low oxygen content in addition to the high volatilization rate of the oxides with high oxygen content have precluded accumulation of reliable data for establishing phase relations. These problems make experimentation difficult, but a modifi-

Jan 1, 1965

GENTLEMEN : It is my privilege to transmit herewith the reports for the calendar year 1932 of your Treasurer and the Chairmen of the following Standing Committees: Finance, Admissions, Membership, Papers and Publications, Library, and Mining and Metallurgy. To these reports you are referred for additional details of the year's activities. Finances.-Continuation of depressed conditions in the mining industry (in common with other industries) caused the income of the Institute to decline from $168,274 in 1931 to $138,331. However, economies were effected so as to reduce expenditures from $171,198 to $135,977. As a consequence the net result of the operations for the year was a-surplus of income amounting to $2,354 compared with a deficit of $2,924 in 1931. This gratifying result is accounted for in large measure by the foresight of the Finance Committee in anticipating a substantial decline in income and preparing the budget accordingly. Incidentally, the tentative budget for 1933 has been balanced at $125,000.

Jan 1, 1932

By Edward H. Robie

IN many ways, the Annual Meeting of the Institute in February was the most successful yet held. Attendance surpassed even that of the 75th Anniversary Meeting in 1947 with its international flavor. The number of technical sessions and the number and quality of papers presented almost certainly set a new record. The banquet was the best attended of any yet held even though the price reached a new high. Despite the demand for almost 1700 tickets to the banquet, some felt that the price-$13.50-was higher than they could afford. There are two points of view: One is that this is the big social event of the year for members and that it is worth from three to five dollars more to have it at the Waldorf and to have a luxury menu, as we did this year, with turtle soup, a fish course, guinea hen for the entree, and wild rice (which we understand is $3.50 per lb) for a vegetable. The other point of view is that a seven or eight dollar banquet of more simple food at the Commodore Hotel would more than make up in appeal, especially to the younger and less well-heeled members, what it would lack in glamour.

Jan 1, 1952

By A. Wahab Khair

This paper presents an analysis of fracture mechanisms in coal subjected to bi-axial state of stresses, indentation of laterally con- fined coal specimen. Coal specimens were loaded to failure by the straight wedge indenters at various lateral confinement pressures. Strain distribution and acoustic emission characteristics of coal specimens under stress were recorded. The influence lines of vertical forces acting on the horizontal straight boundary of the coal specimen for each type of wedge indenter have been established using holographic interferometry technique. The effects of wedge indenter angle, confinement pressure, and coal anisotropy on fracture types, failure modes, and post-failure conditions were studied. The results indicated that combined application of holographic interferometry and acoustic emission monitoring techniques is not only suitable for studying deformability of heterogeneous and microscopically discontinuous material under stress but it also enhances the mode of fracture during the post failure stage.

Jan 1, 1984

By V. V. Strishkov, Zane E. Murphy, George Markon

Soviet industrial expansion depends on coal as a source of power and raw materials for the USSR's metallurgical and chemical industries. Knowledge of the Soviet Union's coal resources and production outlook is essential for a critical evaluation of the Soviet industrial potential. Although there is considerable literature on the Soviet coal industry, no single source provides an authoritative study of how the coal industry functions and how well it per- formed its job. Soviet reports are singularly lacking in the precise data in terms that are comprehensible to a westerner. It is essential, therefore, to clarify the terms in Soviet parlance. These terms are not comparable to those in common use in the West and are the cause of most inaccurate results. Official Soviet data on labor productivity refer to a limited group of "production workers" while in the West all wage earners are counted. Statistics are based on unprepared or run-of-mine coal, whereas it is customary elsewhere to measure productivity in terms of marketable coal. Thus, many western publications, while diligently and accurately reporting published Soviet data, overstate the case, presenting an exaggerated picture of Soviet progress in coal production and technology. (In terms of Western criteria, there is a three-fold exaggeration of labor productivity.)

Jan 5, 1973