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By Thomas T., Read

SUGGESTIONS that existing schools give instruction bearing on the mineral industry, or that schools for that purpose should be established in the United States, began to be made early, and it would require too much space to catalogue them all. Some of the more important may be mentioned to indicate their general character. In the "advertisement to such parents as have now (or expect to have) children prepared to be educated in the College of New York," which appeared in the New York Mercury of June 3, 1754, Samuel Johnson, the first president of King's College, the predecessor of Columbia, said that it was the "design of this college to instruct and perfect the youth," among other things, "in the arts of Numbering and Measuring of Surveying, and Navigation and Geography. . . . and in the Air, Water and Earth around us, and, the various kinds of Meteors, Stones, Mines and Minerals, Plants and Animals; and in the knowledge of all Nature in the Heavens above us, and of everything useful for the Comfort, Convenience and the Elegance of Life . . . " Though the concept that natural science should be used to enlarge the bounds of human life was thus implicit at Columbia from the very beginning (John Stevens graduated from it in 1768, James Renwick in 1807, Horatio Allen in 1823, and A. W. Craven in 1829), it was only during the period of Renwick's professorship of Natural and Experimental Philosophy and Chemistry (1820- 1853) that much attention was given to applied science.* Among the Austin papers, published by the American Historical Association,2 there is a draft in Stephen F. Austin's handwriting of a proposed memorial from the legislature of Missouri to Congress, not only urging "the propriety and utility

Jan 1, 1941

By W. C. Hayes

The site selected for the United States prototype pumped storage project of Union Electric CO. was Proffit Mountain, five miles from Taum Sauk, the highest point in Missouri. Factors influencing final location were: high local relief; satisfactory rock type and structure; and an economic location in respect to existing transmission systems. The upper reservoir was constructed by excavating rhyolite porphyry from the crest of Proffit Mountain and constructing a rock fill dike encircling the area to form a 4350-acre foot reservoir. A 6564-ft tunnel connects the upper reservoir with the generating and pumping facilities. A concrete gravity dam on the East Fork of the Black River forms the 6350-acre foot lower reservoir. Precambrian rhyolite porphyry forms the crest of Proffit Mountain and the floor of the upper reservoir. The tunnel was excavated in rhyolite prophpy, granite porphyry, dolomite, shales and conglomerate. Abutments and the foundation of the gravity dam are in rhyolite porphyry, and much of the valley floor of the lower reservoir is underlain by dolomite and shale. Core drilling provided data on soundness of rock type, structure, depth of weathered zone and potential water loss in the fractured igneous rocks. After a six-year study of pumped storage and cost comparison with alternate stream generating units, the Taum Sauk pumped storage project was authorized by Union Electric Co. on Dec. 11, 1959.' The site selected is located in the St. Francois Mountains of southeast Missouri approximately 90 miles south of St. Louis (Fig. 1). The lower reservoir was provided by damming the East Fork of the Black River, a small tributary of the Black River with a minimum flow of about 1 sec ft. Construction of the upper reservoir was effected by quarrying the crest of Proffit Mountain - five miles from Taum Sauk Mountain, the highest point in Missouri — to provide material for a rock fill dike surrounding the quarried area. This provided a 55-acre mountain top lake with a water depth of 92 ft (Fig. 2). A vertical shaft and tunnel connect the upper and lower reservoirs through the two reversible pump-turbine motor-generator units operating under 800 ft of hydraulic head (Fig. 3). The output rating of the plant is 350,000 kw with daytime generation of about 2.2 million kw-hr under normal use. Night pumping will replenish water to the upper reservoir in about 91/2 hours3. The automatic operation is remotely controlled from the Osage plant and from the dispatchers office in St. Louis. GENERAL GEOLOGY Mountains of the St. Francois area consist of Precambrian granites, granite porphyries, extrusive fel-sites and basic dikes. Basal conglomerates overlain by Upper Cambrian Bonneterre dolomites and shales onlap the exhumed Precambrian knobs and hills and are exposed in the narrow valleys. Cambrian and Ordovician residuum as much as 200 ft thick is present on the slopes of many hills. Proffit Mountain consists of rhyolite porphyry and granite porphyry. All excavation for the upper reservoir was in rhyolite porphyry, and the same rock is present under the Bonneterre at the plant site and under alluvium at the lower reservoir dam site. The region has been dissected to the stage of early maturity with only small upland flats remaining. Considerable local relief (a requisite for the project) approaches 1000 ft. Streams flowing across the Precambrian ridges have formed restricted narrows, termed shut-ins. A shut-in approximately two miles downstream from the plant site provides an excellent site for the lower reservoir dam. TEST BORINGS Preliminary to final approval of the project, 12 test borings were made to determine subsurface geologic conditions (Fig. 2). Drill hole No. 12 at the lower reservoir dam site showed 20 ft of alluvium over solid rhyolite porphyry. Drill holes No. 1, 2 and 3 were drilled in the tail race area to depths of 66 ft, 75 ft and 95 ft respectively, and all bottomed in Bonneterre. Drill hole No. 4 at the plant site provided NX core to a total depth of 98 ft in Bonneterre. Drill

Jan 1, 1965

By GEORGE O. SUMAN

IN THE operation of oil properties there are various difficulties with pumping wells which can often be overcome or greatly lessened if sufficient attention is, directed towards pump and tubing problems. The difficulties referred to are the wearing out of pumps, sanding up of pumps, and the sanding up of the hole. As the perforations in the oil strings are large and the oil and sand loose and unconsolidated considerable trouble is often encountered in pumping wells due to the ease with which' the sand can come into the holes. DETERMINING FLUID LEVEL In determining the proper depth at which to tube a well it is essential to first find out something about the behavior of the fluid in 'the hole: Facts in regard to this natter can be obtained by finding the fluid level on pulling the tubing, by making a pumping test on the well tubed to various depths, and by bailing tests during cleaning out work. In ordinary oil field operations it is customary to take the fluid level at the time of pulling the tubing. This 'can only be done when the pump is not sanded up. There are two methods used in obtaining the fluid level. One method is to note where the outside of the tubing starts, to be covered with fluid when pulling the

Jan 1, 1925

By A. Keil

TO measure the absolute conductivity of metallic specimens it is generally necessary to have exact geometrical shapes and good electrical contact with the test-piece. To overcome limitations of the standard methods, an electronic conductivity-meter* Trade name, Sigmatest; model Dr. F. Forster; Reutlingen, Ger-many. has been developed, which works on the principle of inducing high frequency eddy-currents in the specimens and measuring the reaction of these curients on a measuring coil.',' To attach the instrument to the test specimen, a flat area of about 10 mm diam is all that is necessary. The reading is taken off a scale calibrated in pet of International Annealed Copper Standard. The induced eddy-currents are propagated in a circular motion parallel to the surface. Thickness of the layer included in a measurement depends on the frequency used. With a frequency of 60 kc per sec, the penetration of the currents was 0.8 mm at the upper limit of the scale, and 2 mm at the lower limit. The method is limited to nonferrous metals and other applications have been described elsewhere." The object of the present investigation was to detect the formation and growth of surface layers of differing conductivity, and to determine the depth to which these changes could be observed. A well known phenomenon which illustrates the problem is the internal oxidation of certain silver alloys containing base metal solutes, such as copper or cadmium, when they are annealed in an oxidizing atmosphere.4, 5 Until now, the only methods available for following these phenomenon have been metallo-graphic examination and hardness tests.0, 7 Changes in mechanical properties of copper alloys by internal oxidation were recently discussed in a more general way by Martin and Smith." When measuring these conductivity changes it must be remembered that the only absolute values of conductivity are those of 1) the nontreated homogeneous specimen, and 2) the final values obtained with a surface layer of depth comparable to the penetration of the eddy-currents. All intermediate values refer to the mixed conductivities of the transformed surface layer and the untransformed alloy, and are thus readings of relative value only. Experimental Results Specimens were annealed for 1/2 hr at 800°C in hydrogen, and the internal oxidation was carried out by thermal treatment in air at 800°C. Fig. 1 shows the results of the first series of experiments. With internal oxidation of a solid solution of 8 pet Cd in silver, the conductivity rises continuously until the surface layer formed has become thick enough to be the deciding factor (about 400µ). Precipitates of CdO are mainly in the form of points, Fig. 2, and, as a result, the electric contact between the silver crystals is not distorted by them. Brine11 tests were run with a 1.25 mm ball and a 7.812 kg load. The specimen annealed in hydrogen and oxidized to a depth of 400µ had a hardness of 40 Bhn,

Jan 1, 1959

GENERAL GEOLOGICAL DESCRIPTION The uranium mineral appraisal herein described was made for an ore deposit in New Mexico. The uranium mineralization occurs as roughly tabular to lens-shaped deposits of varying thickness within the sandstone of the Jackpile formation of Jurassic age. The mineralization occurs at several horizons within the Jackpile formation, but is not always confined to specific beds. It often transgresses across stratigraphic layers, as demonstrated when attempting correlation of uranium gamma anomalies between adjacent drill holes. Preferred mineral trends have been established in some parts of the deposit, but are not always predictable when attempting to extrapolate beyond the zones defined by drill hole sampling. MANAGEMENT OF DRILL HOLE SAMPLE DATA All of the drill hole sample data used in the appraisal were obtained from interpretation of gamma-ray logs. A brief description of gamma-ray log sampling is given in Chapter 2. Two preliminary steps are involved in preparing gamma-ray logs into sample data normally acceptable for computer manipulation. 1) The gamma analog trace produced by the downhole probe must be digitized, i.e., counts-per-second (CPS) are recorded for each 0.15 m (1/2-ft) interval across the gamma-ray anomaly. The work is usually done on a "digitizer" while following the analog trace with an electronic stylus on a special tablet or table. The other alternative is to do the work manually. Some of the newest downhole logging equipment produces a magnetic tape output which can be read by a computer. 2) The gamma-ray CPS values must then be converted to equivalent U308 assay values, taking into consideration all appropriate correction factors. The US Atomic Energy Commission, now part of the Department of Energy, developed the theory and algorithm for this conversion in the 1960's, and though the work can be done manually, it is best done with the GAMRED (gamma-reduction) computer program. Fig. 14-1 illustrates a typical analog trace produced by the probe instrumentation, including gamma-ray trace (left), self-potential electric log (center), and resistivity log (right). Fig. 14-2 shows a form of the computer output after the analog data has been digitized to 0.15-m (1h-ft) intervals and converted to percentage U308 values for the same hole. The U308 grade bar graph on the right permits rapid visual inspection of anomalous values by depth and elevation. The converted U308 sample data were next processed by the SURVEY program that assigned to each assay interval [0. 15-m (1h-ft)] an X Y Z coordinate, taking into account all deviations indicated from downhole survey information. The output file of the SURVEY program was listed on the line printer for examination by project geologists, and also became the main input file for the URAN/ COMP compositing program, which is designed to group individual 0.15-m (/-ft) U308 sample values into larger intervals representing discrete anomalous zones according to a series of specified parameters entered into the program by the user. Composite U308 intervals were computed by the URAN/COMP computer program, the logic of which may be briefly described as follows: Step 1 The program searches for the highest U308 value in the hole and builds a composite by adding the highest grade interval on either side so long as the added value is greater than a minimum acceptable grade, and the total composite, after addition, meets minimum GT (grade times thickness) constraints. Step 2 The program loops back to find the next highest assay value in the hole not already included into a composite, until all anomalies above minimum cutoff grade are composited. Step 3 Individual composites are combined if they are closer than a specified minimum waste thickness, and the resultant composite grade still meets GT minimums.

Jan 1, 1980

By HOMER L. WILLIAMS

WHILE some of the mining companies have been pumping a small amount of water for some time, it is only in recent years that large quantities of water have been encountered in the Tonopah district. The water appears to be in different zones or belts so that the draining of one property does not necessarily affect the one adjoining. Consequently, each company has its own pumping plant and its own conditions. The companies panes handling the largest amount of water are the Tonopah Extension Mining Co., Halifax Tonopah Mining Co., West Tonopah Consolidated Mining Co., and Great Western Consolidated Mining Co. The Halifax shaft is on the eastern end of the district and the other three properties on the western. The ore-bearing formation occurs at greater depth on -the eastern and western ends, hence the water problem in these properties.

Jan 1, 1921

"Salt Lake City was founded July 24, 1847, by Mormons under the leadership of Brigham Young. It had a population of 118,110, according to the United States census of 1920, and of 151,968, according to a civic survey, January 1, 1925. The Salt Lake metropolitan district is estimated to have 180,079 inhabitants.The city's area is 51.8 square miles. Its altitude is 4,354 feet. It has 514 miles of streets, of which 91 miles are paved. The streets in the main portion of the city are 132 feet wide and the blocks are 660 feet long. It has 144 miles of street railway and 2,200 electric street lights. It has fifteen parks and playgrounds, forty public schools and six private schools. It has eighty-nine church edifices, of which forty-nine are devoted to denominations other than the Mormon Church.It is the capital of the state, the headquarters of the Mormon Church and the headquarters of most of the mining companies and many other business institutions of the state and adjacent territory.The State University, the State School of Mines and the Inter-Mountain Experiment Station of the U. S. Bureau of Mines are in the eastern part of the city. Fort Douglas is east of the University the country clubs are in the southeastern portion of the city. The State Fair Grounds are in the northwestern portion.The city is the center of a trade area about 700 miles in diameter and is in almost the exact center of a circle that embraces the principal western mining areas. It is the home of several widely-known mining supply companies and all the other leading concerns in that line are represented by agency or branch house."

Jan 1, 1925

By R. H. Tien

Temperature distribution as well as position of the solidified front is solved by means of "heat balance integral", for the case of freezing a slab with time-dependent surface temperature. Numerical solutions for the cases of linear variation and exponential decay for surface temperature are given. Application also includes solidification of casting. An increased interest in the heat-transfer problem involving a change of phase has been developed in recent years. Practical problems include solidification of a casting, freezing and thawing of soil, ice formation, and others. Despite the importance of the topic, a literature search reveals relatively few solutions which may be extended to practical problems. Due to mathematical complexity, which comes from the nonlinearity of governing differential equations, exact analytical solutions which have been published are limited to a few cases with simple boundary conditions. Although numerical solutions of these problems have become available after highspeed digital computers were introduced, lack of simple and general methods of programming for computation makes this approach impractical. The case of the semi-infinite slab with constant surface temperature was solved in the 19th century. In honor of Neumann, who first found an analytical solution, this kind of problem is generally referred to as the Neumann solution. As has been shown in Fig. 1, the problem to be analyzed is the freezing of a semi-infinite region (x > 0) which is initially liquid at the melting temperature with the surface (x = 0) maintained at time-dependent temperature. This analysis can be applied to the study of many casting processes where most of the heat removal is essentially unidirectional. "Heat balance integral" which has been used by Goodman1 is employed in this analysis. The concept of "heat balance integral" is to define a quantity, d(t), called the thermal layer. Beyond this thermal layer, for all practical purposes, there is no heat transfer, and the region is at the equilibrium temperature. "Heat balance integral" is obtained by integrating the conduction equation with respect to the space variable over this thermal layer d(t). Choosing some plausible temperature distribution, usually a polynomial or a finite trigonometric series in the space variable, this integral equation becomes an ordinary differential equation, with time as the independent variable, which can be solved by classical methods. The thermal layer and "heat balance integral" are equivalent, respectively, to the boundary-layer thickness and the momentum integral in hydrodynamics. A modern account of Prandtl's concept of the boundary layer and von Karman's momentum integral may be found in Ref. 2. Although the problem considered here has been limited initially to uniform melting temperature, the present method is equally applicable to the case with arbitrary temperature distribution in the liquid. STATEMENT OF THE PROBLEM The physical situation and coordinate system used in the problem to be analyzed are shown in Fig. 1. Notations used are listed in the table of nomenclature. Let us assume a semi-infinite region extending over positive x, initially at the uniform melting temperature. At the surface x = 0, a time-dependent temperature, which has a numerical value

Jan 1, 1965

By B. DE MARE

THE No. 6 open-hearth furnace at the plant of the Worth Steel Co., Claymont, Del., is the first to be rebuilt according to the Kuehn system. This as well as the other five furnaces at Claymont, has a nominal capacity of 75 tons, but the actual charge is about 242,000 lb. No hot metal being available, the pig-iron is charged cold. Oil of low grade with an asphalt base is used as fuel. These two items have to be kept in mind when discussing the actual fuel consumption. Careful records have been kept covering a five weeks run and the following is a brief summary of them The time required to heat the furnace preparatory to charging from the time a wood fire was started until charging commenced was 36 hours. This, I understand, is much less than with furnaces of standard design. The draft of the furnace, as shown by a gage in the stack-flue, is 1.25 in. The maximum draft with new checkers on former runs was 1.50 in., this draft gradu¬ally decreasing as the checkers closed up. Both of the first helpers claim the present draft is all they need for the proper working of the furnace, and, as with the Kuehn regenerators the draft remains practically the same from beginning to end of a run, this is satisfactory.

Jan 1, 1929

By K. R. Evans

The yield and fracture characteristics of a Ti-8 pct A1 alloy have been examined at room temperature as a function of exposure temperatures to 1700°F. Em-brittlenzent of the alloy is observed to occur following exposures below 1280°F, the critical temperature for formation of ordered Ti3Al particles. Presence of Ti3Al particles results in an increase in the yield and flout stresses which, for a given exposure time, are a maximum at the critical temperature. Embrittlement is attributed to the occurrence of plastically induced fracture controlled by the increase inflow stress. This interpretation is compatible with the decreasing ductility and increasing crack popagation rates observed with increasing exposure time below the critical temperature. Slip line observations and measurements of the gain size dependence of the yield stress indicate that the slip character of the alloy is not influenced by exposure treatments below the critical temperature. ThE potential usefulness of Ti-A1 alloys in structural applications has prompted considerable interest in studies of their microstructure and mechanical characteristics. The relatively recent surge of interest in the system and at the same time its complexities are indicated by the fact that despite numerous recent efforts14 there has not even been general agreement upon a phase diagram for the system. However, most of the Ti-A1 alloys of commercial interest range in aluminum content from 5.0 to 8.5 wt pct where most investigators achowledge the existence of the ordered Ti41 phase. Goldak and parrs confirmed the existence of Ti41 from X-ray diffraction analysis of the stoichiometric composition while Blackburn6 has determined its presence in commercial Ti-8 pct A1 alloys by electron diffraction analysis and dark field transmission microscopy. The embrittlement of Ti-8 pct A1 alloys was initially reported by Crossley and carew7 who showed that aging in the temperature range of 750" to 1110°F resulted in extreme brittleness. This behavior was later confirmed and correlated by Soltiss to the presence of long-range order in the commercial Ti-8 pct Al-1 pct Mo-1 pct V alloy (Ti-8-1-1) which exhibited anomalous creep and yield strength behavior at 950°F. This investigation was designed to study the mechanical characteristics of a binary Ti-8 pct A1 alloy in order to further examine the nature of the embrittlement behavior reported for the alloy system. EXPERIMENTAL PROCEDURE A Ti-8 pct A1 binary alloy was obtained from the Wah Chang Co. in the form of 0.050 in. sheet. The chemical composition of the alloy is given in Table I. Heat-treatment of the alloy was conducted in evacuated vycor capsules for the tensile sDecimens (1.25 bv 0.25 in. gage section) and in evacuated stainless steel jackets for the crack growth-rate panels. All specimens were annealed at 1700°F for 24 hr and water quenched before an exposure at elevated temperatures. Tensile testing was conducted at room temperature in an Instron testing machine equipped with a pushbutton control for instantaneous control of the cross-head motion. In this manner the change in stress, Aa, accompanying an increase in strain-rate by a factor of 10 was measured immediately after yielding. The crack growth-rate panels used were 3 by 18 in. with a precrack 0.33 in. long cut into the center of the panel. The panels were cycled at a maximum gross stress of 40,000 psi at a maximum to minimum tension stress ratio of 20. Cycling of the specimens was continued until the crack propagated the width of the panels. The crack length was intermittently measured during slow crack growth. EXPERIMENTAL RESULTS Correlation of Embrittlement to the Critical Temperature for Ordering. Blackburn6 has found that the critical temperature, T,, for the formation of Ti41 in a Ti-8 pct A1 alloy with an interstitial content on the order of that given in Table I is approximately 1245°F. The relationship between the ductility of the binary alloy used in this investigation and T, was estimated from tensile tests on specimens which were exposed for 24 hr at various temperatures followed

Jan 1, 1970

By Robert F. Mehl

THIS essay is an attempt to present the elementary facts and ideas concerning the growth of crystals, especially of metals. Freezing, like all heterogeneous processes, is a process of nucleation and growth; it manifests itself in metallurgy primarily in the freezing of ingots. The preceding paper in this volume discusses nucleation; the paper to follow describes ingot solidification. The present paper will treat of the growth of nuclei to large crystals, embracing a long series of phenomena, many of which are familiar to metallurgists.† Crystal growth, it will be immediately noted, occurs not only in the freezing of metals, but in the freezing of all substances; and it is a prominent and familiar phenomenon in crystallization from solutions, aqueous or otherwise, and in crystallization from the vapor phase. It will be necessary to include such systems in this discussion, for so much of value to metallurgists has been learned from their study. Apart from this, so far as metals are concerned, it will be simpler to limit the discussion to the freezing of pure metals and of solid solutions. Other types of freezing-eutectic, peritectic, etc.-will be excluded, though they have much of interest and of importance. BASIC MECHANISM OF FREEZING Ideally, nucleation and growth processes can best be considered from the point of view of isothermal reaction and upon the assumption of random nucleation. In. such an ideal case, nuclei form at random, and at a characteristic rate either constant or changing with time, and grow to spherulites at a characteristic rate, constant or changing with time, Fig. I.. On the simplest assumption, the reaction rate-in this case the rate of freezing-is a resultant of these two component rates. The reaction rate equation may be written in terms of these two component rates. The formation of pearlite from austenite closely approaches this ideal case. The ideal case forms a very useful point of departure in considering real cases. Various factors of reality produce deviations from this assumed ideality. In freezing, the isotropic medium, the melt, passes to the anisotropic solid, the crystal. Crystals are lattices of atoms, and the unit cell is often referred to as a crystal unit. Rosenhain, many years ago, represented the nucleation and growth process on freezing in the manner shown in Fig. 2, feeling, intuitively, that there must be some crystal unit in crystal growth. It now appears that this may be true, though his picture requires much elaboration. The greatest deviation from ideality lies in the nonisothermal nature of the freezing process in metals. To approach this properly it should be recalled that many nonmetallic substances freeze slowly. Tammann, to whom we owe the classic approach, studied complex organic materials in which (as in the case of eutectoid steels at high

Jan 1, 1951

By Walter W. Bradley

AT ONE TIME OR ANOTHER and in greater or less amounts, gold has been mined in at least 40 of California's 58 counties. It may not be inappropriate, by way of introduction, to give a brief historical statement relative to her production of the yellow metal. The presence of gold in the gravels of San Gabriel, San Francisquito, and other streams near Los Angeles, was known and they were worked in a small way by the Indians, at least as early as. 1841' and possibly 1820. -On March 2, 1844, Don Manuel Castanares, deputy for California to the Congress of Mexico, reported' to his government that placers near Los Angeles had yielded up to December, 1.843, a total of 2000 oz. of gold dust, most of which had been sent (via Mexico) to tile United States Mint at Philadelphia.

Jan 1, 1932

By Stanley F. French, Bruno F. Koch

Although the amount of dust that will be actually recovered in the six main dust-control systems cannot be accurately stated until the tests mentioned previously are carried out, it is estimated that the average air entering the wet collectors will contain around 5 grains of dust particles per cubic foot. This means that the six systems handling a total of about 133,000 cu.ft. of air per minute will return about 68 1/2 tons of dust to the concentrator per day and since the copper in this dust will average around 2 per cent, the total recovery is approximately 1.37 tons of copper every 24 hours. This important copper recovery is not due entirely to the dust-control system since in a plant without control only the duct that is dispersed to the atmosphere represents a loss. A conservative estimate of the recovery of copper solely due to the dust control system would be about half of the total or approximately 0.70 tons of copper per day.

Jan 1, 1942

By Wido Tilmann

13.6-1. Importance. In Germany there are large tertiary brown coal reserves, most of which are located close to the surface. Therefore, brown coal has been recovered for many years by means of opencast methods. By utilizing a high degree of technology, a rational operation has been achieved, and as a result, the mining techniques have become renowned all over the world. After the war, all the dredgers and overburden spreaders, as well as the means of conveyance, had to be redeveloped for adapting this equipment to the changing conditions of the deposits. Numerous auxiliary machines were adopted from the American earth moving industry and altered according to the different requirements. As a result of such technical developments, the output per man and per shift was increased remarkably in spite of the deterioration of the geological conditions. In the whole of Germany, the total reserves of brown coal amount to 100 billion metric tons, of which 60 billion tons are situated in the Federal Republic of Germany. In the latter area, 8.5 billion tons will be recover- able by opencast means, of which 3.5 billion tons are already developed. The annual output reached 102 million tons in 1965. This total figure comes from four different mining districts: Rhineland, Helmstedt (town at the border of the Soviet occupied zone), Hesse, and Bavaria. The production figures (1965) are as follows: [ ]

Jan 1, 1968

By T. W. Turk, S. A. Sass

The engineering design features of the Mercur Gold Project crushing, grinding, carbon-in-leach, bullion, reagent, and tailings disposal areas will be discussed in this paper. It presents a project overview and flowsheet along with selected design alternatives. During the engineering phase, major equipment and other features were selected to optimize design within site location and environmental constraints. The project team organization and procedures were adopted to accommodate multiple optimization studies while maintaining a tight engineering schedule.

Jan 1, 1985

By David R. Mitchell, R. M. Fleming

MANY trends were evident in the coal industry during 1951. Some were favorable for the industry; others were not. Probably those having the most far-reaching consequences are those affecting coal's markets. The rapid dieselization of many railroads and the continued trend toward oil and natural gas for home heating has caused serious dislocations in various mining districts. Mines have been forced to close down or to work on a reduced time basis. Conversely the increased activity in the metallurgical industries has increased the demand for coking and special purpose coals, and the growing production of electric energy has increased the demand in certain areas for steam coals. The increased demand for metallurgical coal and for steam raising by the large utilities is more than equal tonnage-wise to the loss of coal to railroad dieselization and conversions to oil and gas in the domestic market. Since much of the expansion is at captive mines of large corporations, many commercial operators supplying railroad and domestic users have had their markets curtailed without any compensating demand from other sources. Feverish activity was in evidence in many areas by commercial operators attempting to find new markets. The Norfolk and Western Railway is the, only major American railroad committed to the burning of coal. It has an exceptionally good cost record. During 1951, fifteen additional modern coal-burning steam switching locomotives were authorized for construction in the company's Roanoke shops at a cost of about $1,450,000. When the new order is completed the road will own a total of sixty locomotives of the modern-switcher type, including thirty acquired by purchase last year. The Norfolk and Western today is the only American railroad building its own motive power. All of these locomotives burn coal. Production Coal production in the year 1951 will approximate 570 million tons of anthracite, bituminous coal, and lignite. Of this, approximately 7 pet is anthracite. Total production is approximately 30 million tons more than in 1950 and reflects the increase in general industrial activity. Exports are expected to be close to 50 million tons. The industrial stockpile is close to 75 million tons, the highest it has been since 1943. With the exception of the usual local stoppages the year 1951 was unmarked by labor disputes. It was a year of good labor-management relations with a negotiated wage increase unmarred by a work stoppage. This may be the beginning. of an era of sensible negotiations to find agreeable settlements of disputes without the usual protracted bickering and industry-wide strike. The United Mine Workers of America has condemned wildcat strikes, stating that in nearly every, instance proper grievance procedures have not been instituted. Government defense organizations, perhaps profiting by their experiences during World War II, are pursuing a more enlightened program with regard to the fuel requirements of the nation. Many prominent officials have stated that wherever possible coal should be considered the primary source of fuel in all defense expansion. With the increased consumption of steel by defense projects, approval of transportation facilities for liquid and gaseous fuels have been refused where these fuels would enter a coal producing area. Liquid and gaseous fuel producers also have failed to provide satisfactory evidence that they have sufficient reserves and are capable of supplying their product in adequate amounts for the periods of time required. Realization has at last become prevalent that the hydro-electric power installations in several areas are insufficient to handle increased demands.' Steam generating plants are being constructed in these areas and equipped to burn coal. Most notable of these, is the TWA area whose supplemental steam power plants are expected to consume 10 million tons of coal per year when completed. The Pacific Northwest is another area which is expected to follow the same pattern. Nearly all new steam-power generating plants are being equipped to burn coal either as a primary fuel or as an emergency measure. Metallurgical Coal The steel and other metallurgical industries are expanding rapidly to meet increased industrial demands and defense orders. Since these industries are dependent on coke, coke has had a year of high production and can be expected to break all existing records when steel-plant expansions are completed. Most notable of the expansion projects is that of the Delaware River area where the iron ore will be received by ship from Canada and South America. U. S. Steel is only one of several steel corporations that are planning on putting integrated steel producing units in this area. The Defense Solids Fuels Administration announced in December that through. November 30, 1951. 29 projects in eight states, with a total cost of

Jan 1, 1952

By W. B. Plank

THE figures on enrollment in the engineering schools of the United States and Canada indicate that the total number of students in these schools for the current year, 1949-50, is about 10% less than it was a year ago. This year, 226 - 533 undergraduates and graduate students are studying engineering in the United States and Canada as compared with. 249,913 students last year. These figures are taken from advance data in the Journal of Engineering Education for February 1950.

Jan 1, 1950

By W. C. PAGE

AS the pioneer operation treating the mixed lead- zinc-iron ores from the district tributary to the Salt Lake Valley, the International Smelting Co.'s plant has offered an extremely interesting and instructive opportunity to study some phases of this problem. Basically, there were two main reason for our attempting to work out a successful operation for the separation and concentration of the values contained in the rather widespread deposits of these so- called lead-zinc ores. In the first place, the time was ripe and demanded some method of curtailing the economic waste resulting from the costs of past and present practice of smelting ores of this character, or rather, those ores which could stand the charges inherent with smelting them. Secondly, but rather primarily with us, we believe that such a solution would greatly in- crease in general the production of lead in the district tributary to the Salt Lake Valley. It is generally known that there were and are three relatively large lead smelting plants in the Salt Lake Valley and the decreasing production of correspondingly clean lead ores was not efficient to justify the existence of all three. We could not hope for better lead smelting metallurgy nor more efficient business management than was being practised, so the only prospect was to at- tempt to work out some way to increase the primary production and thus widen the scope of operations.

Jan 1, 1926

By Thomas L. Kesler

Essentially all of the barite produced in Georgia has come from the Cartersville district in the northwest part of the state. The earliest recorded shipment of ore, 60 tons, was made in 1894.1 With the exception of the four-year period 1931 to 1934, the separate yearly output has been recorded and published since 1915, whereas the total yearly output of the United States has been published since 1880. The separately recorded production of Georgia (Cartersville) through 1947 is 2,232,544 short tons valued at $14,900,746,2 but unpublished data on the period 1931 to 1934, plus the estimated unrecorded output prior to 1915, make the actual total about 2,400,000 short tons. This is about 21 pct of the total production of the United States, which, through 1947, is 11,328,440 short tons valued at $71,683,386.2

Jan 1, 1949

By R. J. P. Lyon, A. E. Prelat, H. Lawrence

Introduction In 1977, the US Bureau of Mines awarded a grant to the state of South Carolina to explore the possibility of using Landsat multispectral scanner (MSS) data as an aid in monitoring surface mining activities in selected counties of the state. Work had been done in Aiken County prior to the grant by USBM and state personnel at the EROS Data Center using both the GE Image 100 and ESL IDIMS systems. The initial work on the 1:100 consisted of locating and measuring the areas of various kaolin mines. The results were excellent on location, identification, and accurate area measurements of several mines as compared with aerial photos of each mine. The effort also included locating and measuring the size of all mines (including sand and gravel) within two US Geological Survey (USGS) 7 % - min quadrangle maps. Line printer overlays using the IDIMS equipment and software resulted in the location of all known mines within an estimated error less than zt 91.4 m. Mine acreage was calculated by counting each symbol (which represented one pixel) and multiplying by 1.1 (the number of acres per pixel). [Fig. 1] shows a portion of one quadrangle overlay. [Table 1] gives a comparison of acreage measured for several mines from the 1-100 and IDIMS system vs. aerial photo measurements. The success of the preliminary work resulted in the South Carolina Land Resources Conservation Commission submitting a proposal to USBM for funding to expand the scope of work to other mineral mining operations within the state and determine if Landsat Imagery could be used to accurately locate and measure mining and reclamation activity on a continuing basis. Three separate tasks were proposed for selected kaolin mines in Aiken County: Task 1, to measure changes in active mine developments over the period 1974-77; Task 2, to measure reclamation activity, and, if time permitted, seasonal changes in mine signatures over the same period of time; and Task 3, to classify one complete mining operation (i.e., differentiate between active, spoil, overburden, water, reclaimed portions and surrounding terrain. The major effort was centered around J.M. Hubeis Richardson mine. Mining operations were progressing in a northerly direction and included three areas of reclamation: one prior to 1974; one started during early 1974; and one reclaimed during 1976. A discussion of all work done under the grant is available in the March 1979 Final Report listed under References. Computer compatible tapes (CCTs) containing MSS data from Landsat Path 18, Row 37, were purchased from the National Aeronautics and Space Administration (NASA) covering the period February 1974 through January 1977. The MSS data were processed on the General Electric Image 100 using parallelepiped classification at the EROS Data Center's Data Analysis Laboratory, Sioux Falls, SD, and at the Stanford Remote Sensing Laboratory, Stanford University, Palo Alto, CA, utilizing both an unsupervised classification (ISOMIX) and a supervised classification (sequential discriminant analysis). Studies at Stanford University Remote Sensing Lab (SRSL). In Feburary 1977, initial work was begun at Stanford using the STANSORT computer program running on a DEC PDP-10 (Honey, Prelat, and Lyon, 1974). This software is fully interactive and designed to study Landsat CCT data at high resolution (small areas) on a pixel-by-pixel basis (Lyon, 1977). Unsupervised Classification. The initial step was to locate the Richardson mine on the positive print of the full Landsat scene from CCT 1644-15252, dated 6/17/74. This was relatively easy due to a large abandoned kaolin mine and a long narrow pond clearly visible in the scene. Two unsupervised classifications of the Richardson mine were run using ISOMIX clustering (Honey, Prelat and Lyon, 1974). (ISOMIX essentially follows the interactive clustering procedures of ISOCLS Kan, Holley, and Parker. 1973). Although the classifications were successfully accomplished, it was apparent from the TV display that the results did not clearly define the mine areas. A supervised classification would have to be made in order to clearly separate each portion of the mine. Supervised Classification. This classification was done using the Stepwise Discriminant Program (BMDO7M) which is part of the BIOMED package (Dixon, 1970) and involved the following steps: Training group populations were selected and the digital

Jan 1, 1982