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By Ronald D. Hill, Roger C. Wilmoth

The neutralization of acid mine drainage is becoming a common practice in the eastern United States. Over 200 plants are now in operation. Lime is the neutralizing agent utilized in most treatment plants; however, limestone may have an economic and practical advantage. Current research efforts of the Federal Water Quality Administration, both inhouse and through grants, to develop and demonstrate the use of limestone are reported. In essence, a state-of-the-art review is presented.

Jan 1, 1972

By R. K. Bowden

In an effort to gain a better understanding of shale joint behaviour, normal-only and shear creep tests were performed on artificially prepared shale joints. Pre- and post-test surfaces were examined for changes in morphology. This paper discusses both of these programs and the results derived from them.

Jan 1, 1984

By E. H. Rutter, J. Hadizadeh

The development of microcracking with progressive strain through failure in an orthoquartzite has been studied by means of optical and electron microscopy of specimens deformed experimentally at 200 MPa confining pressure, 20°C. Microcrack maps and statistics have been prepared. The rock fails through the development of arrays of microcracks which form around grain boundaries and are initiated at notches on pore spaces. No special microstructural characteristic appears to be associated with the peak strength, and axially oriented cracks do not begin to develop until well past the strength peak. Axial microcracking is a precursor to shear fault localization. Because most cracks form in highly shear stressed orientations, it is inferred that most of the work done in rupturing the rock is against the frictional forces on crack surfaces. An attempt is made to integrate the work done in this way, to compare it with the work done by the external forces.

Jan 1, 1982

J. L. McK. YARDLEY,* Pittsburgh, Pa. (written dlscussion ?) .-It is interesting to observe how closely Mr. Hansen agrees with other investigators to the effect that the art of electrolytic zinc has left the realm of mystery. In his introduction, lie has said practically what Thomas French said in his paper "The Future of Electrolytic Zinc. "1 The successful electrolysis of zinc from sulphate solutions has not been an easy matter, and it is only within recent years that the difficult problem of depositing high-grade zinc has been satisfactorily: accomplished on a commercial basis. The principal requisite is. that the electrolyte shall be quite free from certain impurities. The methods by which freedom from these impurities is assured are now very well understood, and with experienced superintendents there is little difficulty in obtaining a high efficiency in that part of the process. When certain underlying principles are recognized, the difficulty encountered in dealing with the filtration of the acid and slimy solutions also largely disappears, although it has been a very serious one to the uninitiated. In the dissolving of the zinc from the roasted ore, there is nothing which any competent chemical' engineer cannot undertake, and any other operations connected with the electrolytic process are either of little or no difficulty, or are common to the retort process. Mr. Hansen also agrees with R. G. Hall's statement in " Some Economic Factors in the Production of Electrolytic Zinc:"2

Jan 10, 1918

By D. Turnbull, J. H. Hollomon

THERE is a large body of evidence'" indicating that solidification during the liquid-solid transition is usually induced by heterogeneities present in the liquid. By dispersing liquid metals into small droplets, the impurities responsible for catalyzing solidification are isolated within a small number of these droplets. The effect of the foreign body therefore is restricted to a single drop by this technique. Thus upon cooling below the melting temperature, solidification is initiated by homogeneous nucleation in the majority of the droplets that do not contain impurities. In the case of solidification of liquid metals, the activation energy for nucleation is so great that its rate changes by orders of magnitude for a change in temperature of only several degrees centigrade.' Effectively homogeneous nucleation occurs at a critical temperature upon continuous cooling. Thus by microscopic observation of single particles during cooling, a temperature at which the rate of homogeneous nucleation becomes sensible can be determined.3 since at the temperatures at which nucleation occurs in the absence of impurities the rate of crystal growth is extremely rapid, the temperature at which the entire particle solidifies is very nearly the temperature at which the nucleation of the solidification occurs. Thus for liquids that freeze at high temperatures the onset of nucleation can be established by simply observing the temperature at which the marked heat evolution and increase in brightness of the particle occur. For liquids that freeze at lower temperatures the onset of nucleation can be determined by a rumpling and change in shape of the particle resulting from its solidification. The microscopic technique for observing the solidification of small particles has already been described." In earlier papers the nucleation of solidification of pure metals 5,6 and of alloy systems7 showing complete liquid and solid solubility have been described. In the present paper, the observations are extended to a simple eutectic system (Pb-Sn) where the possibility of the formation of two solid phases exists. Metals for the investigation were obtained from the American Smelting and Refining Co. in the form of pure lead and pure tin, 99.8 and 99.9 pct purity, respectively. An ingot of each of the pure metals was made into shot by heating the metals at a temperature about 50 °C in excess of the melting point and pouring the liquid slowly into a container of water at 15°C. Samples of the shotted pure metals were weighed out to make alloys containing 5, 10, 15, 20, 25, 30, 40, 50, 60, 70, 80, and 90 atomic pct Pb. Samples of each alloy were then melted in separate beakers. Each melt was poured through a pyrex funnel into a cylindrical mold (% in. ID). The casting solidified in 10 to 20 sec. The inside of the mold as well as the funnel through which the metal was poured were coated with graphite to eliminate adherence of the metal. Analyses were performed on some of the compositions and are given in Table I. The compositions also were checked for these samples and for those that were not analyzed by determining the spread between the liquidus and the solidus upon melting the small metal particles. These measurements agreed as well with the nominal compositions as the analyses listed above. Results The results of the supercooling experiments for the several alloys are summarized in Table II and plotted on the constitution diagram in Fig. 1. Data for the pure lead and pure tin were taken from earlier investigations. The values for the maximum supercooling of the several alloys are the average of several determinations on a number of drops of each alloy. The maximum value in any determination was within about 2 pct of the average. For the alloys containing from 20 to 60 atomic pct Sn, inclusive, two marked changes of the surface structure were observed upon cooling. At the higher temperature, after the first appearance of the solid phase it continued to grow slowly at a constant temperature and then stopped. At the lower temperature the alteration of surface structure was abrupt. For the alloys containing from 70 to 95 atomic pct Sn, inclusive, an abrupt change in surface structure was observed at a single critical temperature.

Jan 1, 1952

By E. Z. Lajtai

The probability distribution of fracture data from a rock mechanics test contains information about the effectiveness of the testing procedure and/or about the nature of the operating failure mechanism. The tensile strength of Lac du Bonnet granite forms a bimodal probability distribution when determined through line loading as in the Brazilian test. The same data obtained from three point bends tests are unimodal. The bimodality can in part be removed by distributing the line load over a finite area. Moisture has the anticipated effect in lowering both the average compressive and the average tensile strength of Lac du Bonnet granite. The reduction in strength however is not uniform within the probability distribution; the change is the largest at low and the smallest at high strength. Conversely, long-term loading is more damaging to the high strength members of the distribution. The large scatter of failure times in static fatigue experiments can in part be removed or even utilized when the probability distribution of instantaneous strength is taken into account.

Jan 1, 1982

By J. A. Knox, R. M. Lasater, J. M. Tinsley

Chemical squeeze treatments have been used to provide temporary relief from certain production problems. The chemical fracture-squeeze technique, combining the effects of a fracturing treatment and a squeeze operation, has been more successful than conventional squeeze operations. Knowledge derived from well stimulation and reservoir engineering research provides a means for predicting the theoretical effective life of such a treatment. Analysis of theoretical equations and concepts developed allows selection of improved treatment techniques based on specific formation conditioins. Theory used in this analysis was developed as an extension of previous electrical model studies made to establish the expected flow and pressure profiles adjacent to a fracture system. The chemical fracture squeeze technique can be utilized in the economic application of corrosion inhibitors, emulsion breakers and paraffin and scale inhibitors. Application of this technique is shown to be effective. The slow return rate of injected chemicals, controlled by the resultant flow profiles and treatment variables, permits extended periods of chemical effectiveness. Results of field treatments are given, showing that the concepts outlined above for chemical fracture-squeeze treatments are valid and that applying this technique can help alleviate many current production problems. INTRODUCTION Much progress has been made in the last 10 to 15 years in developing chemicals for use in stimulating wells, maintaining production and protecting well equipment from damage due to corrosion. Not too many years ago, some wells seemed to dry up or wear out. In many cases the wells were produced as long as possible without any attempt at maintaining productivity. Even with the advent of new and better stimulation techniques, a rapid decline in production was observed. Methods of removing and, in some instances, preventing damage have been developed. Among thosc factors responsible for uneconomical production are scale, paraffin, corrosion, bacteria, water blocks and emulsions. Soluble scale-prevention chemicals have been developed1,2 that can be placed in a formation along with frac- turing sand. As the water produces back across this bed, the solid material dissolves slowly and can provide long-term protection from scale. However, bottom-hole temperature and salinity of produced water vary widely and both these factors influence the rate of solubility. Scale inhibitor composition is also a controlling factor. Some of the solid material may be crushed, increasing the surface area exposed to water and increasing the rate at which it dissolves. Some of the material may never be contacted by water and can be lost. However, this type of treatment has been very successful in many instances and has helped maintain economical production for extended periods of time. Liquid scale inhibitors, which are more widely applicable and more stable, have been developed in recent years; however, because they are liquids, their use has been restricted to treatment down the annulus, using metering pumps to provide proper concentrations in the produced fluid. This has prevented use in wells containing packers, in dually completed wells and in gas-lift and flowing wells. Wells that operate with an open annulus may also experience severe corrosion problems due to introduction of oxygen. Paraffin inhibitors3 have been developed that can be fractured into a well as particulate solids to be slowly dissolved in the produced fluid. These materials are not usually effective in wells with a bottom-hole temperature in excess of 120F since solubility rate may be too fast if that temperature is exceeded or if aromatic content of the oils is unusually high. Corrosion inhibitors have been developed that can be fractured' into a well for long-term feedback, but development of a material with proper solubility or feed rate has been difficult. Corrosion inhibitors are available in many different forms. Liquids have been lubricated down the annulus or sticks or pellets dropped down tubing. Inhibitor squeeze treatments5 devcloped a few years ago led to development of inhibitors with particularly strong film-forming properties.6,7 This technique basically involves displacing a highly concentrated solution of the inhibitor into the formation through the tubing. Kerver and Hanson8 studied the adsorption properties of inhibitors on various types of formations. They showed that, even though the inhibitor was displaced radially into the true permeability, it could be produced back for a long period of time because of slow desorption from the rock. Methods developed for monitoring the return of these inhibitors generally have established 1 to 6 months as the effective limit before retreatment is necessary.9 Inhibitors displaced into the interstices of the formation sometimes cause emulsions that either hamper production or cause treating problems on the surface.

By John F. Blandy

IT is not my intention in this article to consider this subject in the light of the geographer or geologist, but rather in that of the mining engineer, and to endeavor to show the necessity and value to him of studying the minor details of the field or district in which he may be engaged. I t has been said by a distinguished geologist that "the natural boundaries of the geographer are rarely described by right lines. Whenever they occur, however, the geologist may look for something remarkable." And again : " Physiognomy is no idle or doubtful science in connection with geology. The physiognomy of a country indicates almost invariably its geological character." Our country furnishes examples enough of the truth of these remarks, and in no part of it is it so beautifully illustrated as in our own State, which has been so ably described by Prof. Lesley in his admirable little work on the "Topography of Coal." As the great mountain lines become guides to the geologist in determining and mapping out the geography of the formations, so do the minor details of topography become guides to the mining engineer in conducting his explorations, discovering of dislocations, and determining the character of the deposits which are the object of his search. I t is therefore requisite that he should, whilst making his surveys, pay the strictest attention to every variation of the landscape and surface of the ground. Until he has mapped out every feature he may be unable to read the geological changes which may have

By D. O. Hobson

Zirconium single crystals of various specific orientations were fabricated by rolling or drawing. The resulting textures were determined and are discussed with respect to the deformation modes that produced them. The crystals deformed in a predictable manner by combinations of up to third-order twinning with three twinning modes and by slip. Twinning was found to play a major role in initial texture formation. Texture changes produced by slip occurred only at the higher reductions. The twinning sequences that produced each intensity peak during the initial reductions could be identified. Schmid factor criteria were found useful in predicting which deformation modes to expect for each crystal orientation and fabrication procedure. The possible application of these data to poly-crystalline material is discussed. PREFERRED orientation or texture has a significant effect on the properties of most materials, causing anisotropy in fabricated cubic metals and enhancing the natural anisotropy of noncubic metals. This study evaluates the effects of several fabrication methods on the textures formed from specific starting orientations of zirconium single crystals and, it is hoped, gives an insight into the effects of the same operations on poly-crystalline material. BACKGROUND In fcc and bcc metals, texture changes take place by gradual lattice rotations caused by the operation of one or more slip systems. Deformation twinning plays an insignificant role in the deformation of such metals. In zirconium and its alloys, however, and in many other hep metals the ability to twin allows very rapid texture changes to be made with very small amounts of deformation. The deformation systems found in zirconium and its alloys are prism slip and three twinning modes.1 Slip occurs on the {1010}< 1120) system. There is little or no appreciable basal slip in zirconium. The twinning planes, illustrated in Fig. 1, are {1012}, {ll2l}, and {1122}. Two twinning modes, the {1012} and the {ll2l} operate for a tensile stress along the basal pole. A compressive stress parallel to the basal pole is required for {ll22} twinning. These twinning operations cause a 35- to 85-deg reorientation of the basal pole. The {1012} twin is the predominant tensile twin at room temperature. The twinning shears, S, are shown in the figure. A criterion for predicting which deformation system will operate when a grain is subjected to a known stress state is the Schmid (orientation) factor. This factor gives the fraction of the applied stress that computer program was written2 to calculate the Schmid factors for the four deformation modes in zirconium. It assumed three orthogonal stress axes and considered ninety-one different orientations of the basal pole in one octant of this stress space. At each basal pole position the Schmid factors were calculated for seven positions of rotation at 10-deg increments of the unit cell about the basal pole. Schmid factors were determined for a total of 637 orientations and for twenty-four deformation systems in each orientation. The program listed the Schmid factors for uniaxial stress parallel to each axis and, to approximate rolling, or-thonormal biaxial stress was also considered. Fig. 2 shows the range of orientations over which the various types of deformation would tend to predominate in biaxial plane strain with the stresses, equal magnitude. The exact boundary position between regions of different deformation modes depends, however, on the relative values of the critical shear stress for each deformation mode. Fig. 2 is drawn on the assumption that they are equal and it therefore may be only approximately correct. It is also recognized that the biaxial stress analysis may not be applicable in certain crystal orientations. EXPERIMENTAL PROCEDURE Single crystals of zone-refined zirconium, produced by Wilson of this Laboratory,3 were electrical-discharge-machined to form specimens for rolling, tube-drawing, and rod-drawing studies. Specimens were rolled at room temperature on 2-|--in.-diam hand-powered rolls from three different starting orientations: 1) the basal plane parallel to the rolling plane and the [1120] in the rolling direction, (0001)[ll20]; 2) the (1120) plane parallel to the rolling plane and the basal pole in the rolling direction, (1120)[0001]; and 3)_the (1120) plane parallel to the rolling plane and the [1100] in the rolling direction, (1120)[ll00]. Drawing specimens were cut with the [0001] direction as the drawing direction in the tube blank and [1120] as the drawing direction in the rod specimen. The drawing

Jan 1, 1969

By John Hillman

Reconstruction of the British mining industry began shortly after nationalization in 1947 and continued until well into the 1950s with the support of the government. This support diminished as plentiful supplies of cheap oil from the Middle East made many coal mines uneconomic. The planned rundown which followed was foreshadowed in the 1965 White Paper which outlined financial measures to speed the closure of uneconomic collieries. The decline appeared likely to continue into the 21st century as the role of coal in UK energy requirements became less and less significant. This policy was well on course in 1973 when the oil crisis led to a complete reappraisal of the position. A government examination in 1974 of the coal industry then supported the National Coal Board&apos;s general strategy of major capital investment as set out in its &apos; Plan for Coal &apos; .1

Jan 11, 1979

By E. C. Reed

Ninety wells were completed in Nebraska during 1941, of which 42 were producers. One of them was the discovery well of a new field. All of the production to date is in Richardson County. At the close of the year 14 wells were drilling and three more were shut down for orders, hoping for future development of production. Most of the drilling activity was in Richardson County, which had 68 operations; 10 wells were drilled in Nemaha County, 5 drilled or drilling in Gage County, 3 each in Otoe and Furnas Counties, 2 each in Cass, Harlan, Johnson and Sarpy Counties, and 10 wells were completed or drilling over the remainder of the state. The most important development of the year was the discovery in October of the Barada field, sec. 36, T. 3 N., R. 16 E.,

Jan 1, 1942

By E. C. Reed

Ninety wells were completed in Nebraska during 1941, of which 42 were producers. One of them was the discovery well of a new field. All of the production to date is in Richardson County. At the close of the year 14 wells were drilling and three more were shut down for orders, hoping for future development of production. Most of the drilling activity was in Richardson County, which had 68 operations; 10 wells were drilled in Nemaha County, 5 drilled or drilling in Gage County, 3 each in Otoe and Furnas Counties, 2 each in Cass, Harlan, Johnson and Sarpy Counties, and 10 wells were completed or drilling over the remainder of the state. The most important development of the year was the discovery in October of the Barada field, sec. 36, T. 3 N., R. 16 E.,

Jan 1, 1942

By V. N. Mackiw, D. E. Weir, D. J. I. Evans

The world&apos;s largest reserves of nickel are found in lateritic ores. Commercial exploitation has been carried out for almost one hundred years; however, none of the plants currently in operation produce pure nickel but rather ferronickel, matte, impure nickel oxide or mixed sulphide precipitate. Over the past decade Sherritt has studied various processes, including the modified reduction roast-ammonia-ammonium carbonate leach process, for the production of pure nickel powder and briquettes from laterites. Nickel can be reduced to the pure elemental form at elevated temperatures and pressures from impure basic nickel carbonate slurries. Several methods were studied in the development of the process for working up the pregnant leach liquor and basic nickel carbonate to produce feed for the aqueous hydrogen reduction step in which pure nickel powder is produced. This paper is concerned only with the laboratory studies using the basic nickel carbonate slurry reduction procedures.

Jan 1, 1973

MANY members of the National Societies died in service overseas during the World War. No memorial to these engineers has been set up but a unique and interesting suggestion has been made. While Edward Dean Adams, Fellow of the American Society of Civil Engineers, and Associate of the Ameri-can Institute of Electrical Engineers, ,vas in Belgium last June as delegate of the National Societies, En-gineering Foundation, and Engineering Societies

Jan 12, 1927

By A. G. Willard

Quantification of size, shape and composition has been one of the more difficult areas for those concerned with fine particle processing of coal.&apos; Image analysers fed by optical microscopes and by scanning electron microscopes possessing backscatter detectors and energy dispersive facilities now offer techniques to improve the speed and precision of previous methods. This paper discusses the methodology and procedural difficulties associated with the microanalysis of coal. Photographs show display quality on the image analyser monitor and the equipment mentioned. Data illustrating several of the procedures are included. The major portion of data for design and operation of plant for fine particle processing depends on information regarding size, shape and composition of granular material. The lower limits of particle sizes become more important as lower grade deposits are mined. Because of the trends towards treatment of finer materials, the use of image analysis offers advantages in time, effort and accuracy. As energy becomes more critical, the above applies especially to coal processing. The Zeiss Microvideomat 2, a leading member of the second generation instruments, is now available for image analysis. There is a precision television scanning system with monochrome camera, display, control panel and central processor (see Figure 1).

Jan 1, 1980

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Jan 1, 1942

By P. H. Mell

CAN the auriferous slate deposits of the Southern mining region ever be successfully worked? is a question that has been often asked me by persons seeking investments in Southern mines. As the subject is one that has given me much thought during the past few years, I have decided to present my conclusions to the members of the Institute for their consideration. Those who have had the opportunity of exploring the region mentioned above, will readily recall to mind numerous localities, to which their attention was directed by would-be miners, as "rich and desirable properties," in which there were but few quartz seams running in every direction through fine-grained talcose slate. Most of the gold in sued formations was always found disseminated through the slate, and but a small percentage contained in the quartz. Such are the deposits I propose to discuss in this paper. Of course there are many excellent quartz mines in the South that are paying the owners good profits, and many more to my knowledge, that are not being worked for obvious reasons. But it is out of the question to suppose that these slate deposits can be practically

Jan 1, 1881

By Norman Ketzlach

Manganese Products, Inc. has developed a chemical process for the recovery of high-grade manganese oxides from low-grade manganese ores. Ammonium sulphate is also produced. Manganese ore is leached with sulphurous-sulphuric acids. The impurities are removed with ammonia, heat, and air. Manganese oxides are produced by addition of more ammonia and air under pressure. Ammonium sulphate is recovered from the remaining solution.

Jan 3, 1950

The Students&apos; Organization of the Michigan College of Mines was recognized as an Affiliated Student Society by the Board of Directors of the Institute, at a meeting held on April 28, 1916. At the College of Mines, University of Washington, 30 students and instructors took part in the annual spring excursion early in April. Studies were made of the new reverberatory and casting furnaces at the Tacoma smelter, the Du Pont powder works located on Puget Sound and the Britannia Mining and Smelting Company&apos;s mine and mills on Howe Sound, near Vancouver, B.C. The Britannia mills are using Hancock jigs, Burchart tables and Minerals Separation flotation cells to effect a high recovery on low-grade chalcopyrite ore. The Mining Club, University of. Wisconsin, elected the following officers for the second semester of the present school year: J. G. SKIRM, President, H. L. RAU, Vice President, T. C. SHERWOOD, JR., Secretary-Treasurer, H. E. HODGSON, Mucker, , F. M. WOLVERTON, Assistant Mucker. Theo. C. SHERWOOD, Jr., Secretary.

Jan 6, 1916

By W. F. Mullen, C. W. Stickler

WITH few exceptions, unit operations in the Pennsylvania slate industry in 1950 did not differ appreciably from production methods described by Behrel and Bowles2-4 several decades ago. Many traditionally picturesque but relatively inefficient hand operations continued to contribute to high operating costs in an industry in which the margin of profit, for various reasons, was admittedly low. As part of a general program in which the Pennsylvania State College has been assisting the slate industry to solve some of its problems, time and method studies were used in an effort to determine the bottlenecks of production flow. The results are as applicable to other stone industries as they are to slate. A study of the basic elements in the production of roofing slate, structural slate, and slate blackboards among selected slate producers revealed comparatively few refinements. Any marked difference in operating method was characterized largely by the available equipment, a noticeable difference in the working properties of the rock quarried by a particular company, and by either the habit thinking or ingenuity of the individual operators. With the hope that significant economies in manufacture might result, all the unit operations were broken down into elements for study and analysis. The greater part of the study encompassed those operations from the quarry rim to the finished product; however, to obtain a reasonable synthesis of time allotments per operation, several analyses of quarrying from the finish of the wire saw cut are included for reference. The complete study of quarrying made by Bowles several years ago resulted in the introduction of the wire saw into the operation; there appears to be a need for as fundamental a change in the processing of finished slate as the wire saw was in the quarrying process. Fig. 1 illustrates the flowsheet of quarried rock from the parent bed to the quarry rim with the basic elements which contribute to the difficulty of removing slate from the ground. In Pennsylvania roofing slate is produced by one of three procedures, many operations of which are quite similar. In the traditional or classical method the quarried rock is reduced by sculping and auxiliary manual treatment to workable size and then is split and dressed (trimmed to size) in the conventional shanty. Archaic as this method might appear, there are several elements that result in substantial savings over more mechanized operations. In a modified version of this method, the block is reduced by sawing and gouging preparatory to splitting and dressing in indoor stations. This method is particularly adaptable to rock which fractures unevenly by conventional sculping methods. In the third and more modern method, reduced block received from the block maker is diamond-sawed to length and finished on a production line. Fig. 2 illustrates the flow pattern in each case. In the modified and more modern plans, dressing is done on mechanically-operated trimming machines, which appreciably reduce the fatigue factor of the operator. However, it should be noted that it is advantageous for the operator to be able to control the speed of the knife to prevent breakage of certain classes of stock. In the classical plan the splitter and dresser normally act as blockmakers also and carry their eighter slabs (equivalent in thickness to eight shingles) into the shanties themselves, all of which adds to fatigue and reduced efficiency. The extremely low investment and operating expense of the classical method has undoubtedly been of paramount importance in its continuation. Production of Mill Stock The production of mill stock is accomplished by less picturesque methods than enter into the production of roofing slate but it is, in the main, relatively more efficient because of the increased use of machinery for handling and for finishing. Mill stock can be classified into two categories as far as difference in production method is concerned: structural slate and blackboards. The significant difference in operation is caused largely by the nature of the rock used for each product with the best and easiest cleaved rock being reserved for blackboards to permit the splitting of large slabs to as little as 1/2 in. in thickness. Structural stock, on the other hand, is split into panels no thinner than 11/2 in. and

Jan 1, 1952