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HAVING previously told you about lodestone, azure, emery, and manganese, things that perhaps belong more properly to the stones than to the metals, the desire has come to me to describe rock crystal as well and, with this, some of the better-known gems, although they are things that are not classified with metals, as far as I know, or even with the serniminerals. In truth, they are neither one nor the other, but they are stones and have the nature of stones. But let them be what they may, in order to avoid straying from the subject we have begun, we shall say that they have mineral properties in their species, as for instance, in respect to their colors. It would seem an error to me if, while I am giving you information on so many other useful things, I did not give you this as well, if for no other reason than because it is a fine accomplishment for a gentleman to have some knowledge concerning gems. Thus since I have proposed to do this, beginning to speak of crystal, I tell you that it is a lustrous, transparent, and limpid stone, composed by Nature with a predominance of wateriness. Thus, contrary to the order of natural things, it has been believed by many that Nature has generated it of pure water by means of a powerful and continuous coldness that always exists in those mountains and places where it is found, for the waters and snows can never melt there because of the great cold. They have tried to prove this opinion of theirs by saying that crystal still retains the nature of frozen water, and that this is. shown not only in its appearance but also in the fact that, like ice, it floats without sinking to the bottom when it is put in water. They also say that it is customary to put it under the tongues of the thirsty on account of the, coldness and moistness which it gives, and that it quenches the dryness of their thirst. But even if all these things were true, as they are not, they do not upon consideration bring us to the conclusion that it is water, because the diamond and the beryl would do the same. Therefore it does not seem to me credible [391 that it is as they claim, for it is a stone generated as such by Nature. And then, if this were true in those places where it rains often and many snows are formed, and these should freeze and never melt but

Jan 1, 1942

UNDER the same justification that I spoke to you in the preceding chapter on crystal and some other gems, I can now speak much better and with much greater reason of glass, since it is one of the effects and peculiar fruits of the art of fire. Every product that is found [41v] in the interior of the earth is either stone or metal or one of the semiminerals, and glass, as is seen, resembles them all, although in all respects it is dependent upon art. Therefore it seems to me that before coming to the discussion of the arts themselves, I must treat of this very beautiful composition created by art and number it with the semiminerals. Thus in this chapter I shall speak to you of glass, not as a proper semimineral, nor yet as a metal, but as a fusible material that is almost made mineral by art and by the power and virtue of fire, born from the speculation of good alchemistic savants, through whose efforts it imitates. the metals on one hand and the transparency and splendor of gems. on the other. Certainly it is a very beautiful thing and one that should not be left buried in silence, in consideration first of how great a thing art has been, able to discover, and then because its beauty makes it such a pleasing thing for making drinking. glasses and an infinite number of other ornamental things that satisfy the desires of man. I shall begin, then, by telling you, to the credit of the alchemists, how I believe that this thing was found through their desire to make gems; for when they could not bring them to perfection (as also happened with the metals) they made this beautiful and attractive product, glass. However, Pliny says that it was found by chance in Syria at the mouth of the Belus River by certain merchants who were driven there by the fortunes of the sea and forced to stop and disembark there for a time in order to eat. In cooking the food they saw the rocks of that place converted into a flowing, lustrous material. And as they thought about this, it seemed beautiful to them, and when they went away they carried some stones and plants with them. Thus they gave beginning to glass making. But now leaving this discussion it does not matter how it may have been discovered, whether by merchants or by ingenious alchemists. Art is that which has given it being, through many experiments and by addition

Jan 1, 1942

By E. H. Wells, A. Andreas

Greater progress than in any previous year was accomplished by the oil industry in New Mexico in 1936. The total number of completions in the state was 631, of which 549 were oil wells, 21 were hydrocarbon gas wells, three were carbon dioxide gas wells, and 58 were dry holes. The total oil production for the year was 26,804,446 bbl. Compared with the production for 1935 of 20,228,947 bbl., this represented a gain of 32.5 per cent. Of the total production, 25,337,382 bbl. came from Lea County. The average daily nonmarginal well allowable for that county was 115 bbl. the first of the year and 86 bbl. at the close. Production was regulated by the New Mexico Oil Conservation Commission,

Jan 1, 1937

By Edwin A. Zink, Gerald P. Zink, John E. Wolgamott

Recent advances in high-pressure water technology can be effectively employed in underground mining. The new equipment is based on standard industrial water cleaning hardware and is compatible with conventional mining techniques. Three viable applications are addressed: rock drilling, hole notching, and rock bolting. Highlights of test results are presented that were obtained in several underground mines during the last two years of development work.

Jan 1, 1982

By Y. P. Chugh, R. A. Missavage

Moisture has been known to influence strata failures in coal mines for a long the. A concise review of what is known about effects of moisture on strata control with emphasis on the Illinois basin coal mines is presented in this paper. Some approaches to mitigate the effects of moisture-leaving coal in the roof, guniting, shotcreting, application of sealants-are then briefly discussed.

Jan 1, 1982

By J. M. Roberts, N. Brown

The stress-strain behavior of zinc single crystals was measured over a strain range of 10-6 to 10-2. The phenomenon of macroyielding was observed in detail and plastic strains were detected at almost zero-stress. Closed hysteresis loops were observed during loading and unloading in the strain region of about 10-5. From the hysteresis a frictional stress on the dislocation of about 6 psi was obtained. A preliminary analysis indicates that impurities are primarily responsible for the friction. Nonelastic Strains as much as 10 -4 were recovered depending on the amount of prior deformation. Part of the recovered strain occurs instantaneously upon unloading and the remainder occurs at zero stress. The time dependence of the recovered strain was measured. THIS investigation is concerned with the details of plastic deformation preceding the ordinary yield point as measured with the usual strain sensitivity of about 10-4. The approach leads to internal friction observations in the hitherto neglected frequency range below 10-1 cycles per sec. It is believed that if the phenomenon of macroscopic yielding is to be understood, then the stress-strain curve in the neighborhood of the macroyield point should be greatly magnified. It may then be possible to determine whether macroscopic yielding is a unique event or whether it is a process which begins gradually at a lower stress. In the case of low-carbon steel a unique event obviously occurs at the macroscopic yield point as indicated by a drop in the load, but copper appears to exhibit a gradual transition from the elastic to the plastic state. In zinc the yield point is rather abrupt although the data indicates that some plastic deformation precedes large scale yielding.' One of the purposes of this investigation is to determine whether there is an abrupt transition from the preyield microstrain region to the region of macroscopic deformation. Such a rapid transition would support the concept that there is a critical stress for yielding. The concept that yielding is a unique event associated with such phenomenon as activating a Frank-Read source, freeing the dislocation from solute atoms, dislocations cutting through dislocations, or dislocations moving freely by one another, has been expounded widely on theoretical grounds. It is hoped that highly sensitive measurements of strain in the neighborhood of the macroscopic yield point will shed some light on the event known as the "Yield Point". EXPERIMENTAL METHOD 1) Specimens—High-purity zinc was cast into spherical graphite moulds in air and grown into spherical single crystals by the Bridgman method under a positive pressure of Argon gas. Spectro-graphic analysis of cleaved sections from four crystals showed a purity of 99.994 pet Zn. The specimens were acid machined with an 1/8 in. gage section in a form similar to those used by Parker and co-workers.2 Bausch type grips were fastened to the specimen by Epon VI adhesive. The specimens were oriented so that only [1120] (0001) slip occurred. Fig. 1 shows two of the specimens in the grips. Prior to each test, the gage section of the specimen was given a concentrated HNO3 chemical polish followed by alcohol rinsing and air blast drying. 2) Test Method- The shear tests were performed on an Instron testing machine and the experimental set-up was made very "hard". Strain could be measured to a sensitivity of 10 -6 by means of a capacitance gage extensometer. The design and calibration of this type of extensometer to measure microstrain, as applied to pure shear and tensile tests of metals, will be the subject of a separate paper—therefore, only a brief account will be presented here. The method essentially consists of attaching a

Jan 1, 1961

By S. E. Bronisz, R. E. Tate

s-plutonium samples possessing a strong growth texture have been produced by allowing them to transform under pressure from p to a. A fiber texture with [010] parallel to the pressure axis results. The textured samples are expected to be useful in determining the effects of crystallographic orientation on the physical properties of a plutonium, and initial results of measurements of resistivity and mechanical properties are described. THE crystal structure of a plutonium1 is mono-clinic, P21/m, and many of the metal's properties should reflect the crystallographic anisotropy. Unfortunately, it has not yet been possible to grow useful sizes of single crystals of a plutonium. Therefore, few of plutonium's orientation-sensitive properties have been determined as a function of crystallographic orientation. One way to gain information about at least some of the orientation-dependent properties is to study a highly textured sample. Such samples have been produced by cold rolling a plutonium,2 but they are necessarily very small in one dimension. We have now successfully used two other techniques to produce highly textured samples, not limited to small thicknesses. METHODS OF PRODUCING PREFERRED ORIENTATION The texture is produced by causing the plutonium to transform from ß to a while under pressure. It was observed by Gardner3 that applying a compres-sive load during the transformation resulted in the formation of columnar grains of a plutonium, and Cramer4 observed a similar structure in some diffusion couples rolled in the P phase. Neither of these workers, however, investigated the subject beyond these observations. The more flexible of the two methods developed is that of compressive loading. The technique is to enclose a sample of plutonium in a die assembly before applying the load. It is possible, of course, to dispense with the die and simply press the sample between two platens. In this case, however, the unrestrained sample deforms during the pressing, making it difficult to maintain the load and to control the final sample thickness. This compressive loading technique has been used on specimens ranging from 1/4 to 3 in. diameter, with height-to-diameter ratios ranging from 5 : l to 1:6. The procedure begins with loading the sample, a right cylinder of a plutonium, into the pressing die. Plastic deformation of the sample while it is being pressed is minimized by machining the sample so that its diameter is nearly the same as that of the die barrel. Then the loaded die assembly is placed in a vacuum pressing can that fits on a hydraulic press. After a vacuum is achieved the die assembly is heated to 180°C and equilibrated. The load is then applied and the specimen and die are allowed to cool to about 40° to 50°C before the pressure is removed. The resulting sample is composed of rod-shaped a -plutonium grains, the rod axes being parallel to the cylinder axis and the pressing direction. Photomicrographs of the oriented structure are shown in Fig. 1. Although most of the specimen is composed of grains whose rod axes are parallel to the cylinder axis, a thin, peripheral layer consists of rod-shaped grains whose rod axes are perpendicular to the cylinder axis. Presumably, the highly plastic nature of p plutonium leads to approximately hydrostatic conditions during the initial stages of the P — a transformation under pressure. At this time, the grains in the peripheral layer would have grown parallel to the local force direction. During the latter stages of the transformation, the accompanying volume contraction would have eliminated the radial forces, leaving only the axial force and resulting in the growth of the observed structure. The growth texture did not form without the application of pressure. Attempts were made to produce the texture by repeating the standard temperature cycle without

Jan 1, 1965

By M. J. Coolbaugh

Mining potash at depths of 3000 ft or more beneath thick water-bearing sediments in Saskatchewan presented a unique challenge to the North American mining industry. Potash is known to flow under pressure, but the knowledge of its flow characteristics at great depths was inadequate for safe design of mine workings and for assured protection from water above the salt formations. At the 3000-ft. depth of the Canadian mines, the potash is stressed beyond its elastic limit, and therefore mining design must deal primarily with its behavior as a plastic material. Recognizing that careful study would be required in order to assure safety and stability of mine workings in deep potash, IMC initiated an extensive rock mechanics investigation of structural properties of potash and salt under high-stress conditions. This presentation consists of a brief review of the development of some methods of testing potash in the laboratory and in the field; some of the rock mechanics concepts and principles derived; and their application to potash mine design. The mining of potash more than 3000 ft beneath the water-bearing sediments in Saskatchewan presented the unique challenge of designing stable mine workings and assuring protection from overhead water in a material that was believed to flow plastically, but whose behavior as a plastic material was not sufficiently known. Under the stress conditions ordinarily encountered in mining, most rocks behave as elastic materials; that is, they compress slightly under pressure, and rebound when the pressure is released. Salt and potash, however, are different. Even under the relatively low pressures encountered at shallow depths, these materials become slightly plastic and yield to stress by flowing.* The plastic properties become more pronounced at greater depth and pressure, and the question arises as to whether or not the plastic flow will be rapid enough and exert enough pressure to destroy underground structures or interrupt the mining process. It was found, however, that not only was there an insufficiency of information about the behavior of potash and salt, but conventional methods of testing these materials, such as determining the modulus of elasticity, Poisson's ratio, and uniaxial compressive strength, were inapplicable because of the high stress conditions prevailing at the 3000-ft depth. Potash under high pressure, for example, has practically no modulus of elasticity, its stress-strain relationship varies with time, and its compressive strength depends upon the degree of confinement. Elasticity and Stress/Strain Relationship: Fig. 1 shows a standard stress/strain chart for potash as made by the Department of Mines in Canada. Typically, when stress is applied to a hard-rock specimen, the specimen contracts, then expands to its original shape when the stress is withdrawn. This chart illustrates, however, that potash under stress yields to the stress by flowing, and does not expand when the stress is withdrawn. When the applied stress was held constant for 30 min, beginning at points A and C, the strain continued to increase and the potash flowed to points B and D, respectively. Points B, D, F, and H show that the potash did not return to its original shape when the stress was released. Thus it can be observed that potash has practically no elasticity and that the amount of strain depends upon the length of time that the stress is applied. Compressive Strength: The conventional method of determining the compressive strength of hard material is to find the maximum pressure that long slender specimens of the material can withstand without failing. As illustrated in Fig. 2,* line B, a standard 2-in. cube of potash subjected to a conventional type of uniaxial compressive test will exhibit a strength of about 5000 psi. However, the compressive strength exhibited can be made to change by changing the conditions under which the test is made. For example, if teflon plates lubricated with graphite are inserted between the press and the specimen, thus minimizing end constraint, the compressive strength is only about 2500 psi, shown in line A. If a specimen is cut in half, changing the width-to-height ratio to 2 : 1 instead of 1:1, and then tested without lubri-

Jan 1, 1968

By M. V. Lowry

This paper outlines the economic considerations that led to the recent installation of a thickener at St. Joseph LeadCo.'s Balmat, N.Y. mill. To incorporate storage of concentrates, they decided upon a single, unusually deep tank to be used for both storage and thickening. The abnormally high rake lift required was achieved by the novel feature of having the entire drive platform raise and lower. Initial operating problems are described along with the satisfactory solutions. Total costs for concentrate handling before and after installation of the storage thickeners are compared. In Northern New York State, the St. Joseph Lead Co. conducts a 2100 tpd zinc mining and milling operation at its Balmat Plant. Conventional crushing, grinding, and flotation is used to produce a zinc concentrate. For 32 years, from 1930 through 1962, the plant operated with the concentrates going directly from flotation to the filtering, drying, and loading facilities. All of the concentrate handling equipment, therefore, had to operate 24 hrs per day. It also had to accommodate wide fluctuations in tonnage, due to variations in the grade of ore. Many problems were thereby encountered in filtering and drying, but it was never concluded that the cost could be justified for installing a conventional, large diameter thickener. Finally, in 1963, they installed an unconventional thickener that is unusual in several respects. The tank depth is 16 ft instead of the normal 8 ft. The rakes are raised and lowered by having the main drive gear located on a movable platform. Automatic controls are programmed to raise the drive platform and rakes during one shift of storage. During the next two shifts of withdrawal, the controls are programmed to lower the drive platform and rakes. After three years of operating this unique storage-thickener, the conclusion is that a correct choice was made from several alternative schemes for storing concentrates. The various considerations involved in the final selection will here be analyzed, and the design features and installation details will be de- scribed. Operating problems and modifications made to the equipment will next be considered, and finally the effects upon filtering, drying, and loading will be reported. SELECTION CONSIDERATIONS Even without a thickener, concentrate handling had become reasonably efficient at the Balmat Mill by the year 1962. A tonnage that varied between 6 and 25 tph was being handled fairly satisfactorily. The filter cake moisture of 8%% seemed quite respectable, except that two large filters were usually in service. Three filters often had to be operated in order to prevent excessive filter overflow with consequent loss of values. This situation occurred when zinc concentrates from flotation exceeded 20 tph and when filter cloth blinding developed. Over the years, numerous small improvements had been effected, such as: selection of a filter cloth with better flow characteristics; addition of flocculant to the filter feed; and, in 1953, the smallest of three drum filters was replaced by a five disc, 8' 10" diam filter with a bottom agitator and snap blow. As another example of fairly efficient operation, the oil-fired dryer was doing a seemingly satisfactory job of further reducing the moisture content to an average of 3%. However, there were often considerable dust losses when the tonnage suddenly dropped off to 6 tph. At high tonnage rates, the resulting high moistures of 4% and 5% caused difficulties due to concentrates sticking and freezing in chutes leading to the box car loaders. (Drying of concentrates is justified because of the high freight rate for the long shipping distance to the company owned smelter at Josephtown, Pa. near Pittsburgh.) It was long realized that installation of a thickener would permit the subsequent steps of concentrate handling to proceed more smoothly and would alleviate the problems existing in the filtering, drying, and loading operations. It was also realized that even a slightly lower filter cake moisture could mean considerable savings in fuel oil. However, all these factors were never quite sufficient to warrant the expense of a thickener until three more considerations were added to the picture. First, the advent of flocculants meant that a thickener of relatively small area could now be considered. Secondly, a complete renovation of the zinc flotation circuit was made between 1957 and 1961. The

Jan 1, 1967

By O. C. Wheeler

Production in Colombia attained a new high during 1940 when it reached a total of 25,607,976 bbl. Of this amount, the Tropical Oil Co. produced 21;426,492 bbl., including 268,586 bbl. of petroleum condensate, and the Cololmbian Petroleum Co. produced 4,181,484 bbl. from its Barco property. The wildcatting program of different companies in the Magdalena Valley that was initiated during the previous year was continued but with results that were decidedly disappointing. Ten wells were drilled in the Magdalena Valley between the approximate latitudes of Puerto Wilches and Puerto Berrio and nine of these were dry; the tenth was a small producer of no commercial importance. The prospects of finding new fields in the Magdalena Valley thus received a serious setback, since some of the tests drilled were on well developed surface structures. The prospects of the Valley, however, have by no means been exhausted and drilling operations are being continued on other prospects. One additional wildcat was drilled outside the Magdalena Valley on the Colombian Petroleum Company's Barco Concession, which brought to 11 the total number of wildcats drilled in Colom-bia during the year. This well, known as

Jan 1, 1941

By C. T. Bischoff

DURING the past few years geochemical testing for traces of heavy metals in water, soil, rock, and vegetation has aroused increasing interest. Various techniques for field and laboratory determinations have been described in the literature, as have some of the results of application. However, little information has been published regarding application to glacial terrain. Over 90 pct of the Canadian Shield is overburdened, resulting in high costs for mineral exploration once the outcropping ore deposits have been found. This has been largely responsible for the widespread application of mining geophysics in Canada, permitting concentration of effort on area or zones considered most favorable. However, geophysical interpretation has its limitations, since at least 90 pct of the structures indicated thereby contain no valuable minerals. A more direct approach is therefore highly desirable. If underlying base metal mineralization can be detected by sampling soil or vegetation at moderate cost this should prove of great help in locating new discoveries or extending known ones. A large proportion of Canadian ore deposits contain appreciable copper or zinc, even where these are not the principal economic metals. Consequently the field of application is a broad one.

Jan 1, 1954

By O. C. Wheeler

Production in Colombia attained a new high during 1940 when it reached a total of 25,607,976 bbl. Of this amount, the Tropical Oil Co. produced 21;426,492 bbl., including 268,586 bbl. of petroleum condensate, and the Cololmbian Petroleum Co. produced 4,181,484 bbl. from its Barco property. The wildcatting program of different companies in the Magdalena Valley that was initiated during the previous year was continued but with results that were decidedly disappointing. Ten wells were drilled in the Magdalena Valley between the approximate latitudes of Puerto Wilches and Puerto Berrio and nine of these were dry; the tenth was a small producer of no commercial importance. The prospects of finding new fields in the Magdalena Valley thus received a serious setback, since some of the tests drilled were on well developed surface structures. The prospects of the Valley, however, have by no means been exhausted and drilling operations are being continued on other prospects. One additional wildcat was drilled outside the Magdalena Valley on the Colombian Petroleum Company's Barco Concession, which brought to 11 the total number of wildcats drilled in Colom-bia during the year. This well, known as

Jan 1, 1941

By Hallan N. Marsh

The subject of this paper is apt to bring to mind wells ranging from 6000 to over 8000 ft. in depth. However, it is uncommon to pump wells at depths greater than about 5000 ft. Fig. 1 shows the number of wells being pumped at various depths by one company in Southern California. A few companies have a very few wells pumping at depths greater than this. This paper will deal with wells between 3000 and 5500 ft. in depth. Most California oils at these depths are between 25" and 35" gravity. The subject is so broad that it will be necessary to omit many interesting phases, and to treat others very briefly. Power, power transmission equipment, power efficiency, counterbalancing, sucker rods, pumps and volumetric efficiency will be discussed. Power As a source of power, the 50/20-hp. electric motor is generally preferred. Input is generally between 10 and 25 hp. Due to the uneven-ness of the load, an input of 20 hp. on the low range is generally about all that these motors will carry without overheating, in spite of their overload capacity. In some cases the capacity of the motor limits the speed

Jan 1, 1929

By W. J. Keep

We have shown in former papers the influence which aluminum exerts when added to cast-iron, and we have presented in another paper, accompanying this one, the physical properties of the metal aluminum and of some of its alloys. The present paper continues the investigation. The reader will find, in our paper on "Aluminum and Other Metals Compared,"* explanations not here repeated, which will render the diagrams in this paper intelligible. The scale of stresses is laid off on the ordinate which rises from the zero-point of the diagram. The scale of deflections is laid off on the abscissa which runs horizontally through this zero-point. By applying a given amount of stress, then running back to zero, and again applying the same stress, we describe a spring-line, in which the deflections are proportional to the stresses. Generally the deflections exceed this proportion during the original application of stress; and the excess is the permanent set. By laying off from the zero-point a line parallel to the springline, we shall generally find that this new spring-line and the diagram coincide for some distance; that is, that the test-bar is

Jan 1, 1890

One of the newest and most modern surface mining operations in the East is gathering steam at Mapco Inc.'s Martiki mine in anticipation of yielding 2.7 million tons (3 million st) of coal annually.

Jan 10, 1977

By J. R. Lucas, R. L. Frantz

Mine sealing programs for the alleviation of acid mine drainage were begun by the Federal Government in the '30's. As part of an acid mine research project to The Ohio State University, a field test was undertaken to determine the effectiveness of mine seals for reducing mine acid. Details of the tests made at the McDaniels mine show the feasibility of air-sealing and flooding an acid-producing drift coal mine. Work by the University continues. The Federal Government undertook in the early thirties an extensive mine sealing program for the alleviation of acid mine drainage. In the states of West Virginia, Ohio, and Pennsylvania many general summaries have been made on this program but no critical evaluation with supporting data has been found on the effectiveness of mine seals for reducing mine acid. Because of this it was decided to undertake a field testing program as part of an acid mine research project of the Engineering Experiment Station, The Ohio State University. The objective of this phase of the project was to develop and install a field research laboratory for acid mine drainage studies. Specifications for such a mine laboratory were developed and resulted from the following considerations: 1) Size and preservation—the test mine shou1d be of limited size to permit frequent and detailed examinations; it should be in a reasonably sound condition to permit safe entry. 2) Isolation—the mine should be physically separated from all other mines. 3) Openings—a minimum number would be desirable to reduce the sealing problem. 4) Structure—the mine especially near the openings should be structurally sound. 5) Acid production—the mine should be producing significant quantities of acid. After considerable searching, the McDaniels mine was selected in the Hocking coal field in Vinton County just above Lake Hope State Park in southeastern Ohio. The small drift mine in the middle Kittaning coal consisted of two small rooms with one mine opening about 6 ft above a seasonal stream bed. Before it was finally decided to seal the mine, a short study was made of the acid drainage over several months. Fig. 1 shows a plot of acidity (milligrams per liter), flow (gallons per minute), and acid production (pounds per day) vs time over the sampling period. Because the coal was overlain with a porous sandstone, the mine drainage was consistent the year around even though the mine was

Jan 1, 1961

By F. D. Rosi

IT was recently shown1 that slip bands can be observed in bent germanium crystals after deformation, by means of etch pits along the slip traces. It is the purpose of this note to show how chemical etch pits can also be usedto examine the appear- ance of slip bands in silicon, as well as other deformation markings. A 30 ohm-cm, p-type single crystal bar, 2x1/4x1/8 in., was plastically bent at approximately 1200°C in a vacuum of 1x10-5 mm Hg. The axis of the crystal was coincident with a <III> direction, and the surface normal to the axis of bending was within 4" of a (110) plane. Prior to the deformation, the (110) surface was mechanically polished with

Jan 1, 1958

Kaolin deposits in Georgia lie in a belt that stretches across the central part of the state from Alabama to South Carolina. In 1977 the state&apos;s kaolin production was an estimated 4.58 million tons (5.05 million st) or 77% of US production. While mining methods vary, stripping contractor W. F. (Billy) Jackson of Wrightsville, Ga., depends on a fleet of 18 twin-engine elevating scrapers to move the hulk of overburden and clay. Owner Billy Jackson explains that the soil in this part of the state is perfect for scraper operation; overburden ranges from Georgia red clay to a sandy gumbo material. Apart from some shale, very little rock is encountered, thus eliminating any blasting re¬quirement. Most of the material can be removed with cutting edge teeth or with drop center blades.

Jan 6, 1978

The resin-in-pulp (RIP) ion exchange process was originally conceived by the Atomic Energy Commission in the early 1950&apos;s. However it was developed to commercial success by the Anaconda Co. at its 3000-tpd ore processing mill in Grants, N. M. Essentially, the Anaconda mill&apos;s crushing, grinding and acid leaching operations are the same as at the nearby Kerr-McGee mill, except that Anaconda uses manganese dioxide instead of sodium chlorate as oxidant during acid leaching. The real differences between the two mills become evident when considering how Anaconda treats its leached materials.

Jan 8, 1974

By Leon T. Eleiel

Ten years ago a broad knowledge of aerial mapping, coupled with a smattering of geology, qualified one to speak on the subject of the application of aerial mapping to geology. Today, with aerial maps a common tool in the hands of expert geologists on every continent throughout the world, it would be nothing short of presumptuous for the author of this paper, who is not a geologist, to give any geological statements on his own authority. Relatively, today we are only purveyors of general geological gossip, with a definite case here and there by way of illustration. But we can present a story of the really marvellous strides that have been made in the evolution of aerial mapping, built around a skeleton of geological tidbits, from which some useful conclusions may be drawn. The average geologist goes about reading his aerial maps much as one would approach the problem of deciphering a cryptogram. To begin with, typical key expressions appear in recurring sequences and under certain conditions. If once the meaning of these isolated bits of information can be ascertained, the message begins to take meaning. In a similar fashion, the geologist works out his key from aerial maps of territory with which he has some familiarity. He learns that a certain type of thin, white line may mean a vein of quartz. He sees that a certain change in the photographic tone of vegetation on the ground reflects two kinds of soils on opposite sides of a contact. He sees that a certain type of alignment of topographical features often means a fault. He learns that by the erosion pattern he can frequently distinguish soft formations from harder ones. And so, bit by bit, he ties together the information of the picture with his experience on the ground until he develops a reasonably creditable capacity of interpretation. Through the complete gamut of surface conditions, ranging all the way from flat, arid, exposed desert terrain to dense jungle, or rugged mountains, the evidence from which the geologist must make his interpretation varies with bewildering profusion. The quality of photographs which are obtainable may range from perfect pictures in the desert to almost useless smudges in the steaming jungles. One thing he has learned with certainty—the airplane carrying its mapping camera is a superb reconnaissance tool, only awaiting his ingenuity in correlating the pictures with the ground to simplify most exploratory problems.

Jan 1, 1937