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By L. W. Pommier, L. R. Plitt, F. B. Brien

L. R. Plitt (Assistant Professor of Mining and Metallurgy, University of Alberta, Canada.) — It is indeed encouraging to see rheological studies being carried out in a mineral engineering school. The bulk of the work being done today in applied rheology seems to be concerned with the behavior of polymeric solutions and thus has limited application to the solid-liquid systems encountered in mineral beneficiation. The authors have approached the problem by carrying out a dimensional analysis which showed that for power law fluids the drag coefficient, Ds, must be some function of a generalized Reynolds number which has the form: If the power law adequately describes the behavior of a fluid, the dimensional analyses predicts that the Ds - RN function should hold for all values of n' or any other dependent variable. The experimental evi-

Jan 1, 1968

By Baoshen. Liu, Lin Dezhang

Vertical and horizontal movements beyond the perimeter of the open pit have resulted from the development of deep and extensive open pits; the surface point always moves towards the centre of the open pit. The surface movements are not only great in relation to the stability of the open pit slope and the safety of mining operations but also are of significance to the stability of structures and ser- vices on the surface beyond the perimeter of the open pit. Recently, some studies on factors contributing to the surface movements have been carried out. Particular attention has been paid to prediction of vertical and horizontal movements, differential subsidence and horizontal strain and careful assessment of their influences on existing structures in the adjacent area. In the application of the theory of stochastic medium, it is assumed that ground subsidence process has the property of Markov Process. Based on the superposit ion principle, surface movements due to open pit mining are derived from the Kolmogorov Equation, and calculated in a digital computer. Quantitative calculation of surface movements is made according to the method employed in this paper and compared with the results of measurement in Morwell Open Pit, Victoria, Australia and Baiyin Open Pit, Gansu, China. The method of calculation gives reasonably satisfactory results.

Jan 1, 1983

By George Burrell

J. S. HALDANE, M. D., F. R. S., Oxford, England (communication to the Secretary?).-The valuable paper of Messrs. Burrell and Gauger is of special interest to me as, through the courtesy of the management, I had an opportunity of visiting the Portland mine, Cripple Creek, in 1911, in connection with the investigations on acclimatization to high altitudes, carried out on Pike's Peak, near Cripple Creek, by Professors Yandell, Henderson and Schneider, Dr. Douglas and myself.1 The analyses of one or two samples of the vitiated air were entirely confirmatory of those of the authors. A fatal accident owing to two men being lowered down a shaft filled with the gas had occurred in a neighboring mine just before our visit.

Jan 12, 1916

By J. B. Newkirk

ABOUT twenty-seven years ago W. bergl discovered that interesting detail could be seen in an X-ray diffraction spot made with a rock-salt crystal if the recording photographic film were held very close to the reflecting crystal. He also showed that much of this detail could be explained in terms of the deformation structure of the specimen. In the same year, 1931, Fox and parr2 reported that X-ray reflections from a quartz crystal were much more intense while the crystal was undergoing piezoelectric oscillation than when it was at rest. This observation was soon confirmed (and explained in terms of X-ray extinction) by Barrett3 in the United States and by Nishikawa et a1.,4 in Japan. During the next few years Barrett refined Berg's method for making X-ray diffraction micrographs and applied it to the study of metallic crystals. He reported this work in the 1945 annual lecture of the AIME.5 Since 1945 relatively little use has been made of the Berg-Barrett (B-B) method for making diffraction micrographs, though considerable interest in investigating subcrystal structures by other methods has developed. Some of these methods depend upon evaporation6 or chemical etching7 and, therefore, suffer from the occasional intrusion of subtle artifacts such as those recently reported by Hooker for leada and Welsh for aluminum.9 Other methods require the introduction of foreign elements which "decorate" the substructure in some way, thereby rendering it detectable by direct" or indirect1'. visual examination. Still others depend upon complex and often highly questionable analyses of X-ray diffraction line profiles. There have also been a number of related X-ray techniques, such as the Lambot,12 Schulz13 and Merlini and Guinier,14 which have proved to be quite useful for specific applications. Some of these methods give a picture of the substructure which is more or less directly related to the shape and the topography of the specimen. The Berg-Barrett method carries this desirable feature to the limit. Closely related to the B-B method are three photographic X-ray techniques recently described by Lang.15 These methods give beautiful pictures of the internal structure of crystals but are limited by the facts that the required apparatus is rather complex, exposure times are long, and the specimen crystals must be thin. An experimental appraisal which I have recently made of the original B-B method has shown that this simple technique is not only inexpensive and convenient, but can give more information than was apparently realized by its inventors. For example, first-order subgrains in iron-silicon crystals were clearly delineated and their relative orientation subject to description. Also defect structures could be seen within the subgrains and in some materials slip bands could be clearly seen with respect to the topography of the rest of the specimen. This much had already been described by Barrett. However, in the present study it was found that the actual sites of individual dislocations which emerge upon the crystal surface could be located. Furthermore, by a simple procedure, the direction (but not sign) of the dislocation Burgers' vector could be defined as well.

Jan 1, 1960

By Frederick J. McGarry, Fred Moavenzadeh

An experimental investigation of the thermal and mechanical responses of rock materials to laser radiation is described. Specifically, the following three topics have been studied in detail: 1. Temperature measurements on thin discs subjected to laser radiation. 2. Strain measurements on thin discs subjected to laser radiation. 3. Observation and evaluation of cracking and spalling phenomena in constrained and unconstrained thin discs respectively, subjected to laser radiation. In conjunction with the experimental work done, use was made of a heat flow analysis and a stress analysis program developed for this purpose. It was possible to theoretically predict the thermal and mechanical responses of a rock specimen to laser radiation and then compare them with experimental observations. Good correlations were obtained.

Jan 1, 1971

By Maurice Ewing, L. Don Leet

Assuming that wave velocities in seismic prospecting increase as a continuous linear function of the depth, the authors have derived formulas for computing, from two time-distance observations, the amount of velocity increase, depth of penetration and a graphical determination of the path of the vibrations, and have discussed the ground, reflected and refracted waves. The application of the formulas is illustrated numerically. Earlier Investigations Observations of the energy propagated from the center of an earthquake disturbance have been used to give information about the velocities and paths of elastic waves in the interior of the earth. One method of accomplishing this depends on the use of the times of transmission. Herglotz(7) § and Bateman(3) obtained a solution of the integral equation involved, which determines the velocity of propagation at any point as a function of the distance from the center of the earth, with no assumption as to the manner in which the velocity of the disturbance varies with depth below the earth's surface. The expressions on which the value of the time and the form of the ray of propagation depend contain an unintegrable definite integral, involving the velocity as an unknown function of the distance from the center of the earth. Wiechert and Zoppritz(15) obtained a manageable form for this function by assuming a law of variation which required a constant curvature form for the path within each of a succession of concentric spherical layers of the earth. C. G. Knott(9) worked out the problem for the first time by an absolutely rigorous method from the data of observation (Zoppritz-Turner tables), without making any assumptions as to the functional relationship connecting the speed of propagation and the distance from the earth's center. His method is a numerical solution of an integral equation, giving each velocity and the corresponding distance from the center of the earth in figures.

Jan 1, 1932

In opening the meeting I wish to express my greatest pleasure at being able to greet this joint session of the Mining and Electrical Engineers. As engineering develops, we find that the border lines between the different branches of engineering become more and more indistinct; the several fields overlap so much that they are three or four layers deep in places. It is only an accident that we couldn't have had the Mechanical Engineers also as a formal part of this gathering, because they are quite as much interested in this subject as the Electrical or Mining Engineers. A little history may enlighten some of those who have not been close to this work. A year ago last summer, there was brought to the attention

Jan 4, 1919

By John W. Stevenson

At Jim Walter Resources Alabama coal property, the first of twelve projected longwall mining systems started to operate In March, 1979, at the No. 3 Mine. The second longwall started to mine adjacent to the original workings in June, 1980. At the end of 1980, 2 ½ panels had been extracted using the same basic ventilation plan. A single split of air ventilates each longwall panel with intake air traveling the headgate across the face to the tailgate where it is directed and controlled to a 1500 foot deep fan shaft specifically located to exhaust from the longwall area and the gobs associated with longwall extraction. The simplicity of the system makes it easy to understand, apply and control In a relatively gassy coal bed.

Jan 1, 1981

By Reno H. Sales

Since leaving school my efforts have been geared to the task of making geology useful to the mining industry. The responsibility of the economic geologist or mining geologist of today has grown to be more, than that of merely finding a faulted segment of a vein. The very life of our mining industry is at stake. The tremendous progress in every branch of our modern civilization has been made possible through the developments in the use of metals. Many of our great industries, including that amazing field of aircraft production live and thrive only because of metals.

Jan 1, 1942

By Sales, Reno

Since leaving school my efforts have been geared to the task of making geology useful to the mining industry. The responsibility of the economic geologist or mining geologist of today has grown to be more, than that of merely finding a faulted segment of a vein. The very life of our mining industry is at stake. The tremendous progress in every branch of our modern civilization has been made possible through the developments in the use of metals. Many of our great industries, including that amazing field of aircraft production live and thrive only because of metals.

Jan 1, 1942

By D. R. Weir, R. M. G. S. Berezowsky

Pressure oxidation of gold containing concentrates and ores is an effective pretreatment for liberating refractory gold. This is particularly true when an appreciable portion of the gold is associated with sulfides and is not amenable to conventional cyanidation. A brief review of the literature on pressure oxidation of refractory gold materials is presented. The chemistry of the aqueous oxidation of arsenopyrite and pyrite is discussed. Data obtained on pressure oxidation and subsequent cyanidation of concentrates and ores tested at the Sherritt Research Centre are also presented.

Jan 1, 1985

By AIME AIME

SINCE the preparation of the Fall Meeting announcement the Montana Section has extended an invitation to the members traveling to Spokane to make at least a short stop at Butte, en route. Accordingly, the train schedule below has been worked out as an alternative to that announced in the general circular. This will permit a half day in which to visit either mines at Butte or the smelter at Anaconda and an opportunity for an evening meal with our Montana members. An interesting time is assured either way and the chance to renew acquaintance with Butte friends will be well worth will

Jan 1, 1929

The American Petroleum Institute, 250 Park Ave., New York, N. Y. Lacey Walker, Secretary. A complete price list of publications will be sent upon application. The American Petroleum Institute issues a variety of publications; in addition to the Daily Oil Digest ($25 per year) and a weekly Statistical Bulletin ($12.50 per year to nonmembers), a Quarterly is published ($4 per year to nonmembers). Books published by the Institute: American petroleum supply and demand, $3; A series of "Petroleum facts and figures" for each of the years 1928, 1929, 1930 and 1931, $2 for each copy; Function of natural gas in the production of oil, $1; Bibliography of organic sulphur compounds, $4; and "Oil" (Oil Industry Series in one volume), 50 cents per copy. Volumes of the first six annual Meeting Proceedings are out of print, but the Proceedings for the 7th annual meeting in 1926

Jan 1, 1933

By W. F. Holbrook, C. E. Wood, E. P. Barrett

The Blast Furnace Studies Section, Metallurgieal Division, Bureau of Mines, has been working for several years on the mechanism of desulphurization of iron and steel by slags. The usual assumption that desulphurization takes place by diffusion of FeS from metal into slag and subsequent reaction of this FeS with CaO to produce CaS has seemed to us inconsistent with a number of experimental results we have obtained. We undertook, for example, to determine the proportion of sulphur in a slag present as FeS. An entirely satisfactory method of doing this has not yet been evolved. The results of extraction with metallic antimony led to an interesting conclusion, however. FeS is readily soluble in metallic antimony, either physically or by chemical reaction. On the other hand, CaS was found to be insoluble. Hence it would appear that by rapid extraction of the slag with antimony we might expect to determine the distribution of sulphur between iron and calcium. The results showed that much of the sulphur was present as FeS. In some instances the extraction of sulphur as FeS was almost quantitative. For example, in a slag containing 3.8 grams Fe and 3.7 grams S, extraction removed 1.18 grams S and 2.12 grams Fe. If all the iron present in the antimony had been FeS, 1.21 grams S would have been extracted. In another slag with 8.6 grams Fe and 0.06 gram S present, 0.14 gram Fe and 0.08 gram S were extracted. This was obviously extraction of sulphur as FeS within the analytical error and showed that FeS was present either in solution or as a dispersion. Attempts to determine the solubility of FeS and CaS in slag by quenching and ultramicroscopic investigation have indicated that the solubility of FeS is very low, and that reactions in the slag are probably not to be considered as homogeneous. A more detailed report on these theoretical considerations will be made at a later date.

Jan 1, 1940

By W. F. Holbrook, C. E. Wood, E. P. Barrett

The Blast Furnace Studies Section, Metallurgieal Division, Bureau of Mines, has been working for several years on the mechanism of desulphurization of iron and steel by slags. The usual assumption that desulphurization takes place by diffusion of FeS from metal into slag and subsequent reaction of this FeS with CaO to produce CaS has seemed to us inconsistent with a number of experimental results we have obtained. We undertook, for example, to determine the proportion of sulphur in a slag present as FeS. An entirely satisfactory method of doing this has not yet been evolved. The results of extraction with metallic antimony led to an interesting conclusion, however. FeS is readily soluble in metallic antimony, either physically or by chemical reaction. On the other hand, CaS was found to be insoluble. Hence it would appear that by rapid extraction of the slag with antimony we might expect to determine the distribution of sulphur between iron and calcium. The results showed that much of the sulphur was present as FeS. In some instances the extraction of sulphur as FeS was almost quantitative. For example, in a slag containing 3.8 grams Fe and 3.7 grams S, extraction removed 1.18 grams S and 2.12 grams Fe. If all the iron present in the antimony had been FeS, 1.21 grams S would have been extracted. In another slag with 8.6 grams Fe and 0.06 gram S present, 0.14 gram Fe and 0.08 gram S were extracted. This was obviously extraction of sulphur as FeS within the analytical error and showed that FeS was present either in solution or as a dispersion. Attempts to determine the solubility of FeS and CaS in slag by quenching and ultramicroscopic investigation have indicated that the solubility of FeS is very low, and that reactions in the slag are probably not to be considered as homogeneous. A more detailed report on these theoretical considerations will be made at a later date.

Jan 1, 1940

By C. E. Wood

THE Blast Furnace Studies Section, Metallurgical Division, Bureau of Mines, has been working for several years on the mechanism of desulphurization of iron and steel by slags. The usual assumption that desulphurization takes place by diffusion of FeS from metal into slag and subsequent reaction of this FeS with CaO to produce CaS has seemed to us inconsistent with a number of experimental results we have obtained. We undertook, for example, to determine the proportion of sulphur in a slag present as FeS. An entirely satisfactory method of doing this has not yet been evolved. The results of extraction with metallic antimony led to an interesting conclusion, however. FeS is readily soluble in metallic antimony, either physically or by chemical reaction. On the other hand, CaS was found to be insoluble. Hence it would appear that by rapid extraction of the slag with antimony we might expect to determine the distribution of sulphur between iron and calcium. The results showed that much of the sulphur was present as FeS. In some instances the extraction of sulphur as FeS was almost quantitative. For example, in a slag containing 3.8 grams Fe and 3.7 grams S, extraction removed 1.18 grams S and 2.12 grams Fe. If all the iron present in the antimony had been FeS, 1.21 grams S would have been extracted. In another slag with 8.6 grams Fe and 0.06 gram S present, 0.14 gram Fe and 0.08 gram S were extracted. This was obviously extraction of sulphur as FeS within the analytical error and showed that FeS was present either in solution or as a dispersion. Attempts to determine the solubility of FeS and CaS in slag by quenching and ultramicroscopic investigation have indicated that the solubility of FeS is very low, and that reactions in the slag are probably not to be considered as homogeneous. A more detailed report on these theoretical considerations will be made at a later date.

Jan 1, 1939

By M. L. Requa

This paper is abstracted from the report of the Appraisement Committee of the Independent Oil Producers' Agency, of which the writer was Chairman. The other members of the committee were M. V. McQuigg and R. S. Haseltine. To Thomas Cox, engineer in charge of the investigation, and to his efficient staff of assistants, is due the credit for the detail work necessary in carrying out the plan of the Committee. It treats only of the valuation of the lands, wells, and piping, without going into details of equipment and other features. It was recognized, early in the operation, that the value of oil lands was the value of oil ,to be extracted and marketed, less the costs attendant thereon. Referring this back to the costs in cents per barrel, it became obvious that surface improvements, absolutely necessary in the production of oil, from wells then drilled, had no separate and independent value aside from the value of the land, but that any excess equipment, not necessary for the production of oil from present wells, such as drilling tools, well casing, etc., should be given a present condition value. In valuing the properties of the Independent Oil Producers' Agency, the Committee has considered the following facts: 1. That from each property there will ultimately be produced a certain total quantity of oil. 2. That in the production of that oil a certain total quantity of money will be expended. 3. That a certain total amount of money will be received from the oil. 4. That the total net receipts will be the total gross receipts less the cost of development and production. 5. That the present value of the net receipts must be such an amount that when invested by a purchaser it will be returned with 8 per cent, interest additional during the life of the property. The initial procedure consisted in making a general reconnaissance of the entire district in which the property was located and determining the lithological and structural conditions underlying the area. The data obtained from each individual tract comprised the logs of all the wells

Jan 1, 1918

The first National Industrial Conference was disbanded without accomplishing the results hoped for. A second conference is to be called in the near future. In response to suggestions of members of the Founder Societies, the following telegram was sent, Oct. 29, to the President and each member of his cabinet. "Engineering Council respectfully recommends appointing on new Industrial Conference two or more engineers familiar with industrial problems. Council represents five national societies of professional engineers having forty-one thousand members. Washington office in McLachlen Building."

Jan 12, 1919

By M. W. Bartley, Hugh M. Roberst

ERRATA In the paper (Mining Technology, January 1943) Page 19, second column. Line 5 should read: of Lower Huronian and Early Middle Huronian. Page 20, second column, line 17. Read magmatic solutions instead of magnetic solutions. In the discussion (Mining Technology, September 1943) On page 2 of this discussion pamphlet there is a typographic error. In the chemical analysis, the first reaction should read: CaCO3 + H2O = CaO2H2 + CO2 AMERICAN INSTITUTE OF MINING AND METALLURGICAL ENGINEERS

Jan 1, 1943

By Milton E. Wadsworth

INTRODUCTION The purposes of this conference are aimed mainly at the treatment of fine or ultra fine particles in terms of beneficiation and chemical processing of minerals. For this reason the discussion on leaching will be confined to processes which treat slurries rather than those which treat a large variety of low and medium grade materials by vat leaching or dump leaching techniques. This eliminates such hydro-metallurgical systems as solution mining from consideration. This discussion will focus predominantly upon the behavior of fine particles as associated with their chemistry in leach reactors. Four major sub-headings may be pointed to as encompassing the major areas in which research and engineering design activity should be directed. These are: 1) generation of fine particles, 2) heterogeneous kinetics of leaching, 3) solution chemistry, 4) engineering design and control of flow reactors. Each of these topics will be addressed briefly in this presentation to illustrate current developments and future needs. GENERATION OF FINE PARTICLES As will be pointed out more quantitatively in the next section the generation of fine particles has great influence upon leaching systems inasmuch as in most cases the rate of leaching is related to the surface area of the particles involved. This is true for acid or base leaching of oxide minerals as well as a large variety of sulfides which have been considered in commercial processes and which have in the case of copper received increased attention during the past decade. Mean particle sizes of slurries vary broadly depending upon the type of grinding equipment being used. For example, in the agitation leaching of uranium ore the slurry typically consists of particles approx-

Jan 1, 1979