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By S. D. Baumer, P. M. Hulme

B. M. Larsen (U. S. Steel Co., Kearny, N. J.)—Could we have some sort of an estimate on the cost of calcium carbide for this treatment? Also, if you used calcium carbide on carbon-saturated iron, would some effect hold back the reaction? P. M. Hulme (authors' reply)—As far as I know we have not worked on carbon-saturated iron. About 3½ pct C is the highest we have worked on. As far as cost goes, it depends on how much sulphur You have to take out. It will run anywhere from $0.75 to $2.00 a ton overall cost including the cost of carbide per ton of metal treated. That is, using the efficiencies that we show in this paper. We are getting better efficiencies now. T. L. Joseph (University of Minnesota, Minneapolis, Minn.)—Did you say 2 lb of calcium compound? Mr. Hulme—That is based on 10 lb of calcium carbide per lb of sulphur removed. D. E. Babcock (Republic Steel Corp., Youngstown, Ohio)—We have run this type of desulphurization process at the blast furnace. We have desulphurized between 100 and 200 at the blast furnace and taken the iron right out of the furnace with an injector system. The process gave us quite varied results; stratified iron, high sulphur on the top and low sulphur on the bottom, and we decided it was impractical. Mr. Hulme Just what was the type of injection equipment? Dr. Babcock—Nitrogen gas for one injection method and we used fairly large gun equipment. We followed the same general type of pattern you show only on a larger scale. Mr. Hulme—It sounds very much like what we call the gale of wind method. We have very erratic results with that. Dr. Babcock—We have tried several types, and particle sizes. The operation was not satisfactory. Mr. Hulme—Of course, we have never tried it on that scale except on a continuous basis. That is the reason we abandoned the idea of working on 35 ton ladles on a batch principle and took it as it came out of the cupola and treated it on the fly on a continuous basis. Dr. Babcock—When you compare the relative effectiveness of the process as carried out, it does not give a very favorable comparison of that process which is already developed. We did not feel it was worth the

Jan 1, 1952

What has happened to the basic coal industry during the past year? Has it been a better year for coal than 1961? What striking new developments have occurred in mining, preparation and utilization? Are there positive signs that production will go up? What has happened in the utility market, the metallurgical market and the export market? Is the controversial question of coal transportation nearer to a solution? What progress has research made for coal during the year? The answer to these and many other important questions are offered in the following review of the Coal Industry-1962.

Jan 2, 1963

By C. M. Marquardt

Tramp iron and steel moving on a conveyor belt cause small currents to be generated in a coil situated in a strong magnetic field, which are converted to an alternating current and are amplified. The output voltage from the amplifier fires a thyratron with a relay in its anode circuit, which actuates a howler and simultaneously drops a spot of marker material on the belt.

Jan 1, 1950

Harry HaRkness Stoek, whose sudden death on March 1,1923, was a great shock to his friends in all park of the country, was a man of remarkable personal characteristics and mental ability. Through an acquaintance with him of nearly 35 years, during 12 yeam of which I was intimately associated with him both in business and socially, I learned to appreciate his many high qualities, his strict adherence to high professional and social ideals, and his lovable traits of character. In this appreciation I was joined by every one who was thrown in close personal contact with him. He was a conscientious student, not given to hasty judgments, but when he formed an opinion he was positive in upholding it. At the same time, he was most courteous and kindly in combatting that which he believed was erroneous. In fact, I never knew a person of his attainments more modest, forceful and kindly, or one who had a keener sense of clean humor. In his private life,he was a devoted husband and father, a consistent communicant and worker in the Episcopal Church, and was charitable in all things. In fact, his whole life was marked by helpfulness to others and a determined and successful effort to "make the world better by his having lived in it." Doctor Stoek was born in Washington, D. C., Jan. 16, 1866. His early education was obtained in the public schools of that city and he graduated from the Central High School in the first class to graduate from a high school in Washington. He entered Lehigh University in 1883, graduated in 1887 with the degree of Bachelor of Science, and after a year of post-graduate study in mining and metallurgy he received the degree of Engineer of Mines. During the summer vacation in 1885, he served as an assistant in the Department of Mineralogy in the National Museum at Washington, and during the summer of 1887 acted as U. S. Government inspector of dredging on the Tharnes River, Connecticut. From June, 1888, to January, 1900, he was assistant engineer for the Susquehanna Coal Co., at Wilkes-Barre, Pa. From January, 1890, to June, 1893, he was Instructor in Mining, Metallurgy and Geology at Lehigh University, and had charge of all courses in mining and metdlurgical design, and the visits of students to mines and metallurgical

Jan 1, 1923

Harry HaRkness Stoek, whose sudden death on March 1,1923, was a great shock to his friends in all park of the country, was a man of remarkable personal characteristics and mental ability. Through an acquaintance with him of nearly 35 years, during 12 yeam of which I was intimately associated with him both in business and socially, I learned to appreciate his many high qualities, his strict adherence to high professional and social ideals, and his lovable traits of character. In this appreciation I was joined by every one who was thrown in close personal contact with him. He was a conscientious student, not given to hasty judgments, but when he formed an opinion he was positive in upholding it. At the same time, he was most courteous and kindly in combatting that which he believed was erroneous. In fact, I never knew a person of his attainments more modest, forceful and kindly, or one who had a keener sense of clean humor. In his private life,he was a devoted husband and father, a consistent communicant and worker in the Episcopal Church, and was charitable in all things. In fact, his whole life was marked by helpfulness to others and a determined and successful effort to "make the world better by his having lived in it." Doctor Stoek was born in Washington, D. C., Jan. 16, 1866. His early education was obtained in the public schools of that city and he graduated from the Central High School in the first class to graduate from a high school in Washington. He entered Lehigh University in 1883, graduated in 1887 with the degree of Bachelor of Science, and after a year of post-graduate study in mining and metallurgy he received the degree of Engineer of Mines. During the summer vacation in 1885, he served as an assistant in the Department of Mineralogy in the National Museum at Washington, and during the summer of 1887 acted as U. S. Government inspector of dredging on the Tharnes River, Connecticut. From June, 1888, to January, 1900, he was assistant engineer for the Susquehanna Coal Co., at Wilkes-Barre, Pa. From January, 1890, to June, 1893, he was Instructor in Mining, Metallurgy and Geology at Lehigh University, and had charge of all courses in mining and metdlurgical design, and the visits of students to mines and metallurgical

Jan 1, 1923

By H. M. Howe

A Discussion of the paper of Professor Howe, presented at the London Meeting, July, 1906, and printed in Bi-Monthly Bulletin, No. 14, March, 1907, pp. 169 to 274. SECRETARY'S NOTE.-M. Beutter's introductory remarks, being simply a resume of Prof. Howe's paper, with a disclaimer of the intention to criticise it, have been omitted, and the remainder of this contribution has been somewhat condensed, without omitting any essential statements. M. BEUTTER, St. Etienne* (communication to the Secretary-+):-Professor Howe observes in paragraph 47 of his paper that the fluid-compression of steel. diminishes piping by forcing the liquid and viscous metal, while the pipe is forming, or after it has formed, into the space so produced, and proceeds to study the different systems of compression, alluding to the four principal ones: Whitworth, Illingworth, Williams, and Harmet. Having now for many years had in use the last-named process, that of M. Henri Harmet, I shall attempt to explain the difference between it and the three other processes named. The Harmet process does not diminish or close the pipe after it has formed, but prevents it from forming; and I may add that it is the only one of the four which produces this result. It is true that the Whitworth process diminishes the interior hollow by localizing it around the central axis of the ingot, which is afterwards removed by trepanning the hollow forgings for which this process has been, I believe, always exclusively used. The Illingworth and Williams processes, which, in my opinion, are applicable only to small ingots, of necessity allow the pipe to form, or (to use the expression of Professor Howe) they allow the surface of the lake of liquid steel to sink into the interior of the ingot, since they involve waiting a certain time before compression, so that (in the case of the Williams process) the ingot-mold can be opened without dan¬ger, or (in the case of the Illingworth process) so as to avoid the risk that the steel may enter the grooves produced by the removal of the distance-bars. During the time required for

Jul 1, 1907

By D. W. Fuerstenau, J. H. Brown

The paper by Professors Sun and Mitchell illustrates the value of ultrasonics as a tool for the mineral engineer. In particular, it opens up a number of possibilities to those interested in the field of comminution. The provision of desliming technique, which is thorough as well as rapid, is a distinct contribution, but the data of the paper suggest applications beyond desliming, in that the same treatments may be useful for size determination purposes. Fig. 1 shows that a marked dependence exists between particle size and the height to which it can be elevated by ultrasonic vibrations. While the curves are only extended down to a size of about 100 u, the fact that they appear to be increasing in slope in this range suggests that the separation may be even more marked here. This, we feel, is very strong evidence that a nlethod for fine sizing could be developed to use ultrasonic waves as the separating force. Professors Sun and Mitchell indicate that floccula-ti~n will present no difficulty: "During the investigation it was found that ultrasonic waves were able to dislodge the adhering gangue particles from the min- era1 surfaces and to disintegrate the soft particles into fine sizes." Thus, it appears that the use of ultrasonic waves as the power behind a size separation process may eliminate the problem of flocculation encountered in most wet sizing techniques. It would be interesting to size a fine material under conditions in which particles are known to be flocculated and under conditions where they are known to be dispersed. Use of a sizing technique of this nature may solve several problems that have long persisted in the fine sizing field. The flocculation problem may be overcome; the continuous production of closely sized fractions may be possible with a device similar to the one described; and with photoelectric methods, rapid analyses in the subsieve sizes may be possible. In general, we suggest that this paper be followed by a study of the sizing applications of the apparatus described. We feel that such a study would not only be rewarding in providing a new sizing technique, but also that the present paper almost requires such work to complete the picture of particle motion in a field of ultrasonic waves.

Jan 1, 1958

By A. R. Kinkel

Robert T. Walker and Woodville J. Walker (Walker Engineering Corp., Salt Lake City)—Mr. Kinkel's article embodies, in condensed form, the results of the first detailed and complete geological survey that has ever been made of the long neglected but potentially very important West Shasta Copper-Zinc district, in Shasta County, California. In view of the difficulties of the terrain and the complexity of the geological structure, this represents a notable achievement, and it is with regret, therefore, that the writers find it necessary to differ from Mr. Kinkel's conclusions on two important points. The first has to do with the interpretation of two members of the stratigraphic column of formations in the district; for purposes of comparison, the description of these two members according to Mr. Kinkel is shown parallel to the description of these members according to the writers, see Fig. 14, Mr. Kinkel's nomenclature being used. The first member, which Mr. Kinkel terms the upper unit of the Balaklala rhyolite, consists of a single, massive, homogenous body of very silicious igneous rock, consisting almost wholly of quartz and albite, and averaging about 80 pct silica. Most geologists of the U. S. Geological Survey who have previously inspected the district have called it an alaskite. It is not a pile of several members, but is a single unit, without internal subdivisions. It has the form of a recumbent lens, approximately flat on the bottom and arched on top, several miles in diameter, and attaining a maximum thickness of 1000 to 1200 ft. It varies in texture from porphyritic to holocrystalline, and contains unusually large quartz phenocrysts up to 4 mm diam. Mr. Kinkel considers this formation to be a thick lava flow that is older than the overlying Kennett shale, while the writers interpret it as being intrusive, constituting a domed sill or laccolith that is younger than the Kennett shale. Their reasons are as follows: 1) This formation shows none of the features which within the writers' experience invariably accompany very silicious lava flows. Nowhere is it vesicular; nowhere does it contain any glass or its devitrified equivalent; nowhere does it contain flow breccia; and nowhere has it a ragged top, in spite of the fact that there is no evidence of surface erosion, which might have removed such a top.

Jan 1, 1957

By W. C. Williamson, J. L. Shugert

DUST control is receiving considerable attention today by most companies as is evidenced by the many articles, papers, and books written on the subject. ~~~t of the larger mining companies have given this subject close study and have established standardized methods of control. W. C. WILLIAMSON and J. L. SHUGERT, Members AIME, are Assistant Ventilation Engineers, Anaconda Copper Mining Co., Butte, Mont. San Francisco Meeting, February 1949. TP 2705 A. Discussion of this paper (2 copies) may be sent to Transactions AIME before Feb. 28, 1950. Manuscript received Jan. 17, 1949. Permissible Limits: The question of permissible dust limits has been considered by medical commit-ties and various national conferences. Dr. Lanza, of the Metropolitan Life Insurance Company, Dr. Le-roy U. Gardner, of the Saranac Laboratory for the study of Tuberculosis, and Dr. Pancoast, of the University of Pennsylvania, have been members of these committees. A statement included in reports of some of these committees is as follows: Concentrations to which the dust must be induced in order to be safe have not been absolutely determined. There is evidence that a concentration of more than five million particles per cubic foot of a highly siliceous dust is dangerous. Therefore, it may be stated that it is desirable to avoid counts of more than five million particles of dust containing free silica to a high percent in working places. Table I gives the safe limits adopted by several state industrial codes. Table I. Safe Limits of Dust Concentration Limit Million Particles State Per Cu Ft Cal~fornia Silica (less rhdn 10 pct) 50 Silica (10 pct to 50 pcr) 10 Sllica (more than 50 pct) 5 New York Frcc silica less than 10 pet by weight of rock formation 100 Frec silica more than 10 Pct by weight of rock formation 10 Oregon Silica (over 40 pct) 5 Silica (20 to 40 pct) 10 Silica (10 to 20 pet) 20 Wisconsin 15 million particles, under 10 nicrons in longest dimension per cu ft of air, when the quartz content of the dust is 35 pct, variations in free silica content will make proportional inverse changer in this standard Close attention to dust concentrations has been given to mining operations, since these operations are frequently carried on at considerable distances

Jan 1, 1951

By T. J. Woodside

Prior to 1927 the lead blast furnace charge at El Paso consisted principally of direct-smelting carbonate ores, very low in zinc, and the resulting slag seldom carried more than 4.0 pct. With the exhaustion of the mines in Northern Mexico which supplied these ores, they were supplanted with a much smaller tonnage of sulphide concentrates containing appreciable amounts of zinc, and the zinc content of the slag rose to 10.0 pct. The Anaconda Company's slag fuming plant at East Helena, Montana, had then been in successful operation for several years, and it was immediately recognized that, while at that time the production of high zinc slag was small, if the grade held, a plant for the recovery of zinc from the accumulated slag might some day be practical. The grade not only held but became increasingly higher so that by 1946 suffcient slag had been accumulated to warrant the construction of a fuming plant regardless of future slag production from the blast furnaces, and with the removal of Government restrictions on construction at the end of the war the project was undertaken. The general design of the plant follows that at Bunker Hill, with waste heat boiler, unit coal pulverizers and even more extensive instrumentation and automatic control. The area around the lead blast furnaces is rather congested, being cut off from the nearest feasible site for the fuming plant by the copper plant, so that the most practical route for hot slag transfer is through the converter aisle. For this reason and also to make use of the existing converter cranes to serve the fuming furnace, an unused reverberatory at the north end of the converter building was dismantled and the fuming furnace and boiler located in its place. A flue at right angles to the furnace and boiler runs northward to the U-tube coolers and baghouse (Fig 1). From the bag-house a steel flue runs eastward to an existing and long unused 300 ft con- Crete stack. The coal handling system and de-leading plant lie north of the furnace and east of the cooling tubes and baghouse. The furnace is conventional, 8 X 21 X 33 ft high inside and completely water jacketed (Fig 2). There are 21

Jan 1, 1950

By J. L. Shugert, W. C. Williamson

DUST control is receiving considerable attention today by most companies as is evidenced by the many articles, papers, and books written on the subject. ~~~t of the larger mining companies have given this subject close study and have established standardized methods of control. W. C. WILLIAMSON and J. L. SHUGERT, Members AIME, are Assistant Ventilation Engineers, Anaconda Copper Mining Co., Butte, Mont. San Francisco Meeting, February 1949. TP 2705 A. Discussion of this paper (2 copies) may be sent to Transactions AIME before Feb. 28, 1950. Manuscript received Jan. 17, 1949. Permissible Limits: The question of permissible dust limits has been considered by medical commit-ties and various national conferences. Dr. Lanza, of the Metropolitan Life Insurance Company, Dr. Le-roy U. Gardner, of the Saranac Laboratory for the study of Tuberculosis, and Dr. Pancoast, of the University of Pennsylvania, have been members of these committees. A statement included in reports of some of these committees is as follows: Concentrations to which the dust must be induced in order to be safe have not been absolutely determined. There is evidence that a concentration of more than five million particles per cubic foot of a highly siliceous dust is dangerous. Therefore, it may be stated that it is desirable to avoid counts of more than five million particles of dust containing free silica to a high percent in working places. Table I gives the safe limits adopted by several state industrial codes. Table I. Safe Limits of Dust Concentration Limit Million Particles State Per Cu Ft Cal~fornia Silica (less rhdn 10 pct) 50 Silica (10 pct to 50 pcr) 10 Sllica (more than 50 pct) 5 New York Frcc silica less than 10 pet by weight of rock formation 100 Frec silica more than 10 Pct by weight of rock formation 10 Oregon Silica (over 40 pct) 5 Silica (20 to 40 pct) 10 Silica (10 to 20 pet) 20 Wisconsin 15 million particles, under 10 nicrons in longest dimension per cu ft of air, when the quartz content of the dust is 35 pct, variations in free silica content will make proportional inverse changer in this standard Close attention to dust concentrations has been given to mining operations, since these operations are frequently carried on at considerable distances

Jan 1, 1951

By C. P. PERIN, DONALD BELCHER

T HE production of pure iron by electrolyzing solutions of its salts has been the object of scientific curiosity and research for about 80 years; and in the last two decades a realization of the unusual physical and chemical qualities of electrolytic iron has turned the attention of chemists and metallurgists toward a commercial application of this accumulated knowledge. Thus Burgess and Hambuechen in America, . Cowper-Coles in England, and Fischer in Germany- devised methods, more or less successful, for the electrolytic refining of iron, but none of these processes has yet attained large-scale operation. During the war some interesting ,work was done in France and England on building up worn or defective machine parts by electrodeposition of iron. It remained for the Société "Le Fern in France to carry on the process commercially. For six years Les Fonderies et Forges. de Sainte-Maire et Gravigny and the works of Bouchayer & Viallet at Grenoble have manufactured pure-iron boiler tubes in competition with established practice. The French process originated in the researches of Anthelme Boucher in 1910, and was, not put into operation until several years of experimentation had passed.

Jan 1, 1921

By T. Egleston

AT the Dover meeting of the Institute, Mr. F. A. Canfield showed some of the members a machine which he had invented for dressing mineralogical and geological specimens, which he has since modified and brought to such a high state of perfection, that after having used it for several months in preparing specimens for the cabinet of the

Jan 1, 1876

By T. Egleston

At the Dover meeting of the Institute, Mr. F. A. Canfield showed some of the members a machine which he had invented for dressing mineralogical and geological specimens, which he has since modified and brought to such a high state of perfection, that after having used it for several months in preparing specimens for the cabinet of the

By L. G. Austin

If S (x) is the specific rate of breakage of size x and B (x, y) (see Table 1 for Nomenclature) is the cumulative breakage distribution function, the Herbst Fuerstenau2 assumption is that Inserting this assumption into first-order grinding equations it has been shown" that there are then simple analytical solutions to the grinding equations, as shown in Table 2. In this context "plug flow" is defined as all material passing through the mill in the same length of time, the residence time t. The term "n fully-mixed" means that the mill has a residence time distribution" which can be treated as if the mill were n equal fully mixed sections in series. In addition it has been shown that the assumption of Eq. 1 also leads to simple analytical solutions for closed-circuit, steady-state grinding with an ideal classifier at the mill exit returning oversize to the mill feed. The solutions are also given in Table 2, with µ as the ideal classifier cut size, C the circulation ratio, and Q (x) the size distribution of the circuit product. The specific surface area of these size distributions is where the density-shape factor k. is assumed to be constant with size. In practice, most methods of size analysis or area [ ] measurement have a finite lower limit, so that the integration is really performed from xm, to xm, For a realistic degree of grinding the value of So is dominated by the fine sizes because of the 1/x factor. Consider batch grinding of a feed of size y to y + dy. The batch grinding solution given in Table 2 is then [ ] The fresh surface area produced is the area of the fines plus the area of the original material remaining minus the area of the original material, [ ] Little error is introduced by neglecting the last term on the right-hand side since at t = 0 it is zero, and when t is significant the first term dominates because of the fine sizes produced. In addition, the form of P (x, t) for [ ] realistic values of S (x) 2t ax° is such that the major fraction of fresh surface produced is contained within the bottom 10% of weight of broken material, that is, for sizes for which P(x, t) < 0.1 (providing y is not near x.,). Thus for surface area purposes Eq. 3 can be approximated by [ ] becomes providing again that the feed sizes are coarse relative to xmi. Then the fresh area production is and W is the mass in the mill. The rate of surface production is WK, and the specific surface is Kt. From Table 2, the specific energy is mt/W so surface production per unit energy is [ ] Surface produced per unit energy input = KW/m (8) where m is the energy input of the mill. Clearly, identical reasoning applies to open-cycle, plug-flow grinding, with t replacing t, and Eq. 8 is obtained again. Considering open-cycle, fully mixed grinding, similar reasoning gives P(x) - t S(x) for surface area purposes, and

Jan 1, 1974

FROM the first to the last meeting of t h e Rocky Mountain Club John Hays Hammond served as president. He guided its deliberations when there were any, but that always y o u n g organization was never particularly deliberate. Youth never is. And the Club was the embodiment of the youthful spirit of the West, which considers any- thing can be done if there be but the will to do it. Ham- mond and the others came out of the West, but they, brought the West with them P and in all the far countries in which he has served his profession and in all the honorable offices in which he has served his country, he lived true to the ideals under which he was raised. A Californian, born in San Francisco in 1855, the son of an army officer, Major Richard Pindell Hammond, educated in the public schools of his native city, at Yale, and at Freiburg, he turned early and quickly to mining. He served his apprenticeship as all successful mining men do, as assayer, surveyor, as assistant in ex-aminations and later as principal, and finally as mine manager. Even in those days of beginnings, his future world-wide career was foreshadowed in that Mexico as well as California served as his training school. His first major step up the ladder was in connection with the Bunker Hill and Sullivan mine, where he served in various positions finishing as president and considerable owner. It was from this great lead mine that he was called to South Africa, where he remained a number of years and was the technical expert who guided the great enterprises of Barnato Brothers and Cecil Rhodes. The story of his activity in developing the "deeps" of the Rand and in opening Rhodesia has been often told but is always an alluring one of adventure and accomplish-ment. After his famous escape from death at Johannes-burg as a member of the Reform Committee, he went first to London and later returned to the United States representing both British and American capital in the purchase and development of great mines in all parts of the world. For some years he was general man-ager, consulting engineer, and director of the Guggen-heim Exploration Co., but of recent years he has oper-ated entirely on his own account and with marked success.

Jan 4, 1928

By J. Chipman, H. A. Wriedt

DURING the past twenty years, a considerable background of knowledge has been built up on the chemical behavior of oxygen in liquid iron. Little is known regarding oxygen in liquid nickel or the effect of nickel as an alloying element on the behavior of oxygen in liquid steel. The solubility of oxygen in liquid iron was determined by Fetters and Chipman&apos; and, more precisely, by Taylor and Chipman.&apos; The Ni-NiO eutectic was placed by Merica and Waltenberg"&apos; * at 1438°C and 0.24 pct 0, and this point has been confirmed by others." O It was reported by von Bohlen und Halbach and LeitgebelT that nickel and its oxide are miscible in all proportions at 1600°C, but this report is discredited by observations of others. The melting point of NiO according to von Wartenberg and ReuschV s 1990°C. Approximate values of oxygen solubility at several temperatures were reported by Hensel and Sc0tt.O The data of Krupowski and Balickil0 are inconsistent with those of Hensel and Scott and indicate a solubility less than half that found in the present study. For oxygen solubility in Fe-Ni alloys under pure iron oxide-nickel oxide slags, only the scattered data of von Bohlen und Halbach and LeitgebelT are avail- able. The careful work of Bardenheuer and Brauns" involved silica-saturated slags. The equilibrium between Fe-Ni alloys and iron oxide-nickel oxide slags was studied by zur Strassenu and by Jander and Senf,u but no oxygen analyses were reported. Oxygen in Pure Nickel Apparatus and Nlethod: Samples were taken with a "Taylor sampler" from a bath of molten electrolytic nickel held under an air atmosphere in a magnesia-lined 30 lb induction furnace. Saturation of the melt with oxygen was effected partly by the addition of chemically pure black nickel oxide and partly by the air atmosphere. Samples were taken only when there was a clearly visible oxide phase present. To avoid contamination of this oxide phase, the silica-sheathed Pt—Pt-10 pct Rh thermocouples, by means of which temperatures were measured, were immersed in the melt for the minimum time consistent with accurate reading. Samples and temperature readings were taken only after the furnace had been

Jan 1, 1956

By K. K. Kohli, S. S. Peng, R. E. Thill

Introduction Since the adoption of the Surface Mining Reclamation and Control Act of 1977, which mandates that surface subsidence be an intergral part of the underground coal mine design, there has been a sudden rise of demand on guidelines for minimizing surface subsidence and its associated structural damages. Unfortunately there is no sufficient amount of systematic subsidence data to fill such a gap, although considerable research has been devoted to the subsidence induced damages of surface structures in the past. However, it was said that many surface subsidence surveys have been performed and monitored by coal companies during the past twenty years, and that it will be a great source of information for subsidence engineering design if they can be collected and assembled together. An effort was therefore initiated in the Department of Mining Engineering, West Virginia University, under contract with the U. S. Bureau of Mines in December 1978 to contact each individual coal company in the Northern Appalachian Coal Field for any surface subsidence survey data. After 10 months&apos; survey, the data collected include: 17 longwall panels and 2 room and pillar sections. The data in each panel and section cover the complete set of subsidence survey raw data, underground mine layout maps, surface topo maps, geological loggings showing the stratigraphic sequences and thickness of the overburden, and if available, locations and types of surface structures. On-site visits were followed to study the surface terraines and structures. Interviews were conducted with the owners of the surface structures in most cases about, if any, the history and characteristics of damages. Most subsidence surveys started with the first panel and ended with the second or sometimes, but rarely, the third panel. The first panel may be located in a virgin area but frequently it was adjacent to (on the tailentry side) a mined-out room and pillar section. It must be noted that all of the subsidence data is restricted only to the amount of vertical subsidence and that the horizontal displacement measurement was completely ignored. Primarily due to the fact that vertical subsidence is the most striking feature in a subsidence trough, which is mistakenly considered to be the only critical contributor to surface structural damages, and that a horizontal displacement survey is much more complicated and time-consuming.

Jan 1, 1981

By R. A. Esmonde

This paper describes the building and testing of a prototype welded aluminum truck body to a new design concept. The results of these tests are given along with an outline of further developments in the design and field application of aluminum bodies. The results of field service history are recorded with special reference to types of mining operations, service performance, wear, maintenance and economics of operation. Mention is made of current U.S. usage and predictions given as to future development of aluminum bodies in the mining industry. The use of aluminum for off-highway truck bodies in hauling rock for the mining and construction industries is by no means the novelty that it may seem. In 1932 an aluminum unit proved very satisfactory in service on the Hoover Dam project but at that time the only high strength aluminum alloys available were not weldable and with the high cost of construction, a sound economic case for an aluminum body could not be made. After World War I1 great advances in aluminum welding techniques, using the inert gas shield, combined with the development of high strength alloys with good welded properties and welding characteristics changed the whole picture. Welded aluminum bodies were rapidly developed and by 1958 attention was again focused on the use of aluminum for off-highway truck bodies. EARLY DEVELOPMENT WORK In 1959 Alcan, the Aluminum Co. of Canada, embarked on an extensive development program to prove the durability and economics of aluminum truck bodies for the mining and construction industries. The first step was to design a prototype aluminum body which took particular advantage of the fact that the modulus of aluminum is only one third that of steel. This means that within the elastic range, aluminum moves three times as much as steel which makes it more flexible and capable of absorbing much greater impact shocks. A body was built and mounted on a 22-ton truck and taken to the Jeffery Mine of Canadian Johns Manville Company at Asbestos, P.Q., Canada. Very little information was available as to the order of stresses that were set up in off-highway truck bodies and so it was therefore decided to carry out a test program to find out this information.

Jan 1, 1969

By J. K. Kerver, J. S. Osoba, J. G. Richardson, J. A. Hafford

A detailed study of a number of methods of relative permea-abilitv measurement has been made in a search for the tech-niqrle most suited to routine analysis of cores taken from reservoir rock. It has been found from tests run on the same samples of core material by a number of techniques that the Penn State, Hassler, Hafford, and dispersed feed techniques all yield results which are felt to be reliable. Conditions under which the faster single core dynamic technique may be used are described. Further work on the calculation of relative permeabilities to oil from data obtained by the gas drive method is needed before this latter rapid method can be utilized. Correlations between theoretical studies and experimental results have been obtained in studies of the boundary effect. pressure distribution in two-phase flow, and gas expansion effects. Previous conclusions that the effects of the outflow boundary could be made negligibly small have been substantiated. Results of experimentally determined oil and gas pressure distributions along a core sample during flow are presented. Further studies of the effects of rate of flow in the measurement of relative permeability-saturation relations have shown that results are independent of the rate of flow as long as the flow rate is below the point where inertial effects commence. An analysis of the effects of a severalfold expansion of gas along the flow path indicates that while saturation gradients are induced in the test sample, the errors caused by this phenomenon in relative permeability measurements are small. INTRODUCTION Many pages of literature have been devoted to pointing out the need for relative permeability-saturation relations in reservoir engineering. One of the most attractive ways of obtaining this information is by the analysis of samples of core material taken from the formation in question, and again literature has described man); methods for obtaining these data. It is the purpose of this paper to present the work that has been done in the study of some of these published methods together with some other methods that have been recently developed in this laboratory. Also, a study of some of the factors that influence the laburatory determination of relative permeability-saturation relations is presented. FACTORS WHICH AFFECT LABORATORY STUDY OF FLUID FLOW THROUGH RESERVOIR ROCK To determine relative permeability-saturation relations of samples of reservoir rock in the laboratory, it is important to know what factors affect these measurements in order that the magnitude of these effects can be ascertained and steps then can be taken to eliminate or, in some cases, to minimize them. The factors that have been investigated are the boundary effect, the effect of gas expansion. and the rate effect. Boundary Effect In laboratory experiments in which two immiscible fluids are flowed through a porous medium, there exists a discontinuity of capillary properties at the outflow face. This discontinuity exists became the fluids pass from a region of finite capillary pressure in the sample to a region of zero capillary pressure in an open receiving vessel. The capillary forces existing in the core caupe the rock to tend to retain

Jan 1, 1952