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By A. V. Quine

FOUR years ago several mining operators shook their heads and predicted that Goldfield Consolidated Mines Co. would never be able to mine the zinc-lead ores from the 550 to 650 level areas of the Deep Creek mine. Their prediction was not without apparent justification, for everywhere one gazed, water was spurting or dripping; every hole that was drilled produced more and more water under pressures of 220 to 250 psi, all from apparently unrelated channels. When the volume of water from one level alone reached 2200 gpm with a possible flow of 5000 to 6000 gpm if the area were fully tapped, development work was brought to a halt and the few holes into the water area were grouted off under contract. As zinc prices had completely deteriorated, the workings were allowed to flood. Upon reopening the mine, in late 1950, it was discovered that the relatively few sacks of cement used in the previous grouting operation had done a tremendous amount of good. Consequently it was decided to systematically drill test holes with a longhole machine and diamond drill and to seal all holes with a cement grout solution. After 30,000 ft of drilling, and the pumping of over 20,000 sacks of cement, 15,000 of which were placed in the supposedly impossible 650 level, the company was successful in literally forcing the water out of the ore zones and opening up large tonnages for subsequent extraction.

Jan 3, 1954

By William E. Bonini, Eugene A. Hickok

IN the course of an investigation directed toward expanding ground-water facilities in Essex and Morris counties, New Jersey, the Board of Water Commissioners of the city of East Orange authorized a seismic-refraction survey1 for the purpose of delineating bedrock topography below unconsolidated overburden. Results of the survey were highly satisfactory and led to the preparation of a comparatively detailed bedrock contour map. Knowledge of the bedrock depth and configuration was an important aid in selection of sites for test drilling. The portion of the East Orange Water Reserve under consideration is in the flood plain of the Passaic River about 10 miles west of Newark, N. J. The flood plain is about 175 ft above mean sea level and is bordered by low hills rising to elevations of approximately 250 ft. The bedrock underlying the Water Reserve consists of sandstone and shale of the Triassic Brunswick formation and is covered everywhere by deposits of unconsolidated glacial outwash sand and gravel, lacustrine clay, and recent river silt as much as 150 ft thick. Yield of wells in the sandstone and shale averages 100 to 200 gpm. Since production wells constructed in the sand and gravel aquifer in the buried river valley shown on the contour map (Fig. 1) yield 300 to 1400 gpm, it was proposed to locate additional production wells in this buried valley, where the yields per well would be maximum.

Jan 4, 1958

By George Bell

THE mine and milling plant of Demonstration Gold Mines, Ltd., is near the city limits of Baguio, Mt. Province, P. I. The mine road connects with the main highway to Manila. The nearest railway point is near sea level, approximately 40 miles distant. The Baguio district is very mountainous and has one of the heaviest rainfalls in the world. It is therefore difficult to maintain roads or to impound tailings and mine dumps. All supplies are trucked into the district direct from Manila or the nearest railway point, which means uncertain deliveries and high freight rates. Installation of equipment is difficult and costly. The average elevation at the mine is 4000 ft. and the climatic condi-tions.are ideal except for a three months rainy season. The company generates its own power for mining and milling opera-tions with three 400-hp. Ruston Diesel engines direct connected to 250-kw. General Electric alternating current generators. Labor conditions have been excellent, although at present social security laws are causing some unrest. Labor receives a higher average wage rate in this district than other labor in the Islands. The com-pany also furnishes free living quarters, hospitalization and work-men's compensation. Taxation has been reasonable up to the present time, but some of the new mining legislation may make it difficult to operate and pay dividends. The future depends largely upon the continuation of $35 gold and the political outcome in the Islands.

Jan 1, 1939

By Stephen L. Bolivar, Susan H. Balog, Thomas A. Weaver

A data-classification scheme was developed to detect potential uranium mineralization in the Montrose l º x 2º quadrangle, Colorado. The methodology developed is a rapid and efficient method of resource evaluation on a reconnaissance scale. The necessary techniques were developed and refined to digitize, integrate, and register various large geological, geochemical, and geophysical data sets for the Montrose quadrangle, Colorado, using a grid resolution of 1 km. All data sets for the Montrose quadrangle were registered to the Universal Trans- verse Mercator projection. The data sets include hydrogeochemical and stream sediment analyses for 23 elements, uranium-to-thorium ratios, airborne geo- physical survey data, the locations of 90 uranium occurrences, and a geologic map (scale 1:250 000). Geochemical samples were collected from 3965 locations in the 19 200 km2 quadrangle; aerial data were collected on flight lines flown with 3-5 km spacings. These data sets were smoothed by universal kriging and interpolated to a 179 x 119 rectangular grid (each grid block is 1 km2). A mylar transparency of the geologic map was prepared and digitized. All possible combinations of three, for all data sets, were examined for general geologic correlations by utilizing a color microfilm output. Subsets of data were further examined for selected test areas. A classification scheme for uranium mineralization, based on selected test areas in the Cochetopa uranium district, is presented. Areas favorable for uranium mineralization, based on this scheme, were identified and are discussed.

Jan 1, 1982

By J. E. Campbell, G. D. Calkins, N. M. Ewbank, M. Pobereskin, A. Wesner

GRINDING for size reduction affects the economics of many processes and products. It is essential as the first step in many industrial processes and is also a finishing step for materials with properties depending on particle size, such as talc, cement, and silica sand. Intermediate and fine grinding are vital operations in the U. S. cement industry, which is producing more than 250 million bbl of cement per year.' Wear of the grinding media is a large part of the grinding operation cost. Problems encountered in grinding cement are so complex that evaluation of efficiency and economy of grinding media is difficult.2 It has been especially difficult to evaluate the relative effectiveness of different types of balls because there are no good testing techniques. Many other industrial operations can be evaluated on a laboratory scale with reasonable accuracy. This does not hold true for evaluation of grinding balls. The consistent results obtained in a laboratory test under a given set of conditions are not always borne out in field application. Rough evaluations of the effectiveness of various compositions and types of grinding balls have been made in the field by using a full charge of one type in a mill and comparing the production record with another run using another type of ball. This method is time-consuming and not very precise, as the second run may not have been carried out under identical conditions. Laboratory-scale tests, on the other hand, have yielded inconclusive results, and many investigators have turned their attention to the development of a field testing technique. Field testing small sample lots of grinding balls has been impractical because it is difficult to identify and recover the test specimens from the grinding mill, and individual groups of balls that have undergone different heat treatments can not be separated.".4 To overcome these difficulties, previous investigators have identified the balls by distinctive marks, notches, and drilled holes, but this procedure has three serious drawbacks: 1) Grinding characteristics and quality of the steel balls may be affected. 2) Physical markings may be worn away in the grinding process, especially during a prolonged run. 3) Recovery from the bulk of the charge will be extremely difficult because the markings are hard to see and may be masked by a coating of the product. To circumvent these difficulties, a radioactive-tracer technique was proposed for recovery and separation of steel grinding balls and subsequent evaluation of the various compositions of the balls. The proposed technique involved five basic operations: 1) Thermal-neutron irradiation activation5 of each group of test grinding balls to a different level of specific radioactivity. 2) Addition of groups of radioactive steel-ball specimens into a ball tube mill. 3) Recovery of radioactive steel-ball specimens from the bulk of the mill charge. 4) Separation of the various groups by their specific radioactivity. 5) Evaluation of actual grinding ball wear. Before any physical tests were performed, required neutron irradiation intensity and time were calculated. Probable composition of the steels to be used was ascertained. An examination was made of the radioactive nuclides8 to be formed which would contribute measurably to the radiation level immediately after irradiation and during the test operation. The radioisotopes formed, their types of radiation, and their half lives are listed in Table I. Of these radioisotopes only iron-59 and chromium-51 were significant for the actual wear test. The intensity of radiation that could be detected by a Geiger counter when the test was completed was the basis for the minimum activation level established. The intensity of radiaton that could be safely handled at the beginning of the test was the basis for the maximum activation level, although this was not considered a major problem. Ten groups of grinding balls of various composition and/or surface or heat treatment were to be tested. One group was designated for the minimum irradiation time. The remaining groups were designated for irradiation periods that increased by increments of 33 pct from that of each preceding group. This difference was considered enough for separation and identification of the groups by comparison of specific activity. Potential Hazards: Possible radiation hazards that might be encountered during this experiment were evaluated for the three important phases: 1) the radiation hazard of placing balls and removing them from the mill, 2) contamination of the product cement by radioactive material worn from the balls, and 3) contamination of the steel by the radioactive balls left in the mill. The radiation intensity expected from the whole group of radioactive balls was calculated to be 250 milliroentgen per hr at 1 ft. This meant the balls would require special shielded packaging and warning labels on the shipping containers. In a radiation field of 250 mr per hr a man can work for 1 hr without exceeding maximum permissible weekly exposure. Since the balls could be dumped into the mill in a matter of seconds, relatively little radiation exposure was anticipated at this stage of the operation. If the weight loss in the balls was 7.7 pct per month and the cement feed through the mill was

Jan 1, 1958

By R. Bainbridge

THE Consolidated Mining and Smelting CO. of Canada Ltd. has operated a lead smelter at Trail, B. C., for many years. In order to take advantage of metallurgical advances, as well as to improve materials handling methods, this company, commonly known as "Cominco," commenced planning a program of smelter revision and modernization some years ago. The first stage of this program involved the design and construction of a new blast furnace gas cleaning system. The selection of equipment, the design of facilities, and preliminary operating details of this system will be dealt with in this paper. The essential problem was to clean and collect 100 tons of dust daily from 153,000 cfm* (12,225 lb per min) of lead blast furnace gas which varied in temperature from 350º to 1100°F. Because it was desired to collect the dust dry, either a Cottrell or a baghouse cleaning plant was to be selected. Comin-co's many years of experience with both systems provided a background for choosing the most satisfactory installation. All information pertinent to the two methods of dust recovery was carefully investigated, and it was decided to replace the existing equipment with a baghouse. Very briefly, the reasons for this decision were as follows: 1—A baghouse installation would be practical because the SO2 content of the gas was low and corrosion would not be a problem if the baghouse operating temperatures were held sufficiently above the dew point. 2—Variations in the physical characteristics of fume and dust, which are inherent in this blast furnace operation, should not substantially affect the operating efficiency of a baghouse. 3—For the same capital cost, metal losses (stack and water losses) would be appreciably less in a baghouse. 4—A baghouse would be easier to operate, and would not require the use of highly skilled labor. 5—Operating and maintenance costs of a bag-house would be lower. 6—The only available space for reconstruction was relatively small, and not suited to a Cottrell installation. Once the baghouse system was decided upon, detailed design of the installation was begun. Baghouse Design Gas Cooling: Before the required capacity of the baghouse could be determined, the method of cooling the gas to the temperature necessary for bag-house operation had to be chosen. The problem confronting the design engineers was how best to cool 153,000 cfm of gas from a temperature ranging from 350°F to brief peaks of 1100°F, down to 210°F, the maximum safe baghouse inlet temperature. A survey of existing blast furnace gas temperatures in the outlet flue showed that the normal range was as given in Table I. The obvious choices of cooling method were: 1— cool completely by the addition of tempering air; 2—utilize a heat exchanger; 3—cool by radiation; and 4—cool with water spray in conjunction with the admission of tempering air. The advantages and disadvantages of the various cooling methods were: Air Addition: To cool completely by the admission of tempering air involved tremendous volumes, Fig. 1. For example, to cool 1 lb of blast furnace gas at 450°F requires 1.84 lb of air at 80°F or 1.60 lb at 60°F. As it is necessary to design for peak conditions, it can readily be seen that volumes of tempering air in the order of 1,500,000 cfm would have to be handled. Using the normal design figure of 2.5 cu ft per sq ft of bag area, a baghouse installation comprising some 600,000 sq ft of filter cloth would be necessary. Such design requirements would be prohibitive, not only from a standpoint of capital expenditure, but also because of space limitations. Heat Exchanger: The utilization of a heat exchanger was given serious consideration. A horizontal tube unit using air as the medium to cool the required volume of blast furnace gas from 400" to 250°F was investigated. Cooling above 400°F would be done by water spray, and below 250°F by admission of tempering air. The estimated capital cost of such a unit was found to be prohibitive. From an operating standpoint, there was considerable doubt as to whether the soot blowing equipment provided would effectively keep the dust from building up on the tube surface. The performance of heat exchangers operating on dusty gas in other company operations had not been too favorable. Radiation Cooling: Although somewhat cumbersome, gas cooling by radiation from 'trombone' tubes or other similar equipment (cyclones) is employed in many metallurgical operations. Such an installation was also considered. However, calculations showed that an installation much larger than the space available would be required to handle the gas volume involved. For example, to cool 153,000 cfm of blast furnace gas from, say, 600' to 250°F (i.e., remove in the order of 58,500,000 Btu per hr with heat transfer rates varying from 1.1 Btu per sq ft per hr per OF for the higher temperature ranges to 0.88 Btu per sq ft per hr per OF for the lower ranges) would need a cooling area of some 175,000 sq ft.

Jan 1, 1953

By Harrison A. Schmitt

One of the great copper-producing areas of the world is comprised of five U. S. western states and northern Sonora, Mexico. The Southwest province of this area, covering southern Arizona, south- western New Mexico, and northern Sonora, produces some 55 pct of U. S. copper output and the equivalent of 15 pct of world production. In 1956 the area produced about 550,000 tons. Tucson is approximately the center of the oval- shaped province, which measures only 300 miles on its east-west axis and about 200 miles on its short axis. Northwest of the oval, and forming a tenuous connection with the Utah and Nevada copper fields, is an important operating mine, Bagdad, and also the now inactive United Verde. Along its north- south axis, running from Globe, through Tucson, to Nogales, ten moderate to major copper properties have been discovered or revived during the past 15 years, and five of these in only the past seven years. The latter five properties lie in an area 25 miles in diameter, centering 20 miles south of Tucson. In order of discovery, or revival, they are: Banner's Mineral Hill and Daisy; Cyprus et al's Pima; Duval's Esperanza; Asarco's East Pima (now called Mission mine) ; and Lewisohn's Peach. Total tonnage is estimated at about 250 million tons averaging some 0.90 pct Cu, but ultimate production may exceed this amount since some of the reserve is open ended.

Jan 6, 1959

By C. F. Kaiser, T. J. Roberts, I. A. Thomson

The Broken Hill Pty. Co. Ltd. grate-kiln pelletizing plant located at Whyalla, South Australia, produced a total of 250,000 tons of fluxed pellets during 1970. More than 180,000 tons were exported to Japan, while the remainder was used in B.H.P. Co. blast furnaces. The pellet plant treats high grade hematite ore fines and has a nominal capacity of 1.5 million tpy. The induration equipment includes a grate 12-ft 2-in. wide by 164-ft 1-in. long, a kiln 18-ft 6-in. diam by 118-ft 8-in. long, and a rotary cooler 50-ft mean diam by 7 ft wide. Operating problems encountered in the production of fluxed pellets are detailed. The most significant aspect of the trial was the increased production, from about 5100 tpd up to a maximum of 7100, brought about by the addition of artificial magnetite to the plant feed. Laboratory evaluation of fluxed pellets showed that pellets having a basicity ratio (CaO to SiO2) in excess of 1.2 have excellent physical qualities. Reducibility and compressive strength after reduction were both higher for these fluxed pellets than for normal acid pellets. Although it was not possible to publish blast furnace operating data, blast furnace trials on fluxed pellets indicated that production was higher and dust losses substantially lower, compared with similar operations on acid pellets.

Jan 1, 1973

By S. J. Hruska

Rate expressions for the formation of two-and three-dimensional nuclei on foreign substrates are developed, taking into account previously neglected contributions to the standard Gibbs free energy of formation of critical nuclei. The temperature dependence of critical super saturation data predicted using these expressions is in accord with data for cadmium on copper and sodium on CsCl. EXPERIMENTAL data on the heterogeneous nuclea-tion of metal crystals from the vapor phase1&apos;2 exhibit the temperature dependence predicted by a nucleation rate equation derived by Pound et al.3 In their treatment, the critical nuclei are visualized according to the Volmer4 model as cap-shaped (three-dimensional). Accordingly, it seems desirable to compare these data with a nucleation rate equation which is derived on the assumption of disk-shaped (two dimensional) nuclei. Further, Lothe and Pound5 have recently shown that the standard Gibbs free energy of formation of these critical nuclei contains a contribution which has heretofore been neglected. Thus it is necessary to re-examine these nucleation data using a rate equation which contains this contribution. The van&apos;t Hoff isotherm relates n(i), the concentration of nuclei of critical size i (i = number of atoms), to nil), the concentration of adsorbed single atoms: where standard Gibbs free energy of formation of critical nuclei given by is temperature insensitive and is the bulk free energy change/volume of transformed material], T = substrate temperature and k = Boltzmann&apos;s constant. Previously,3 was determined by considering only the contributions of bulk and surface free energies in transforming i atoms from the population nil) to a cluster of i atoms. It has been shown5 that this procedure does not take into account the free energy contribution arising from the multiplicity of sites, q, where the clusters can be situated. If this contribution, -kT In q/n(l),is added to iG3 [Note that this increases n(i) by a factor q/n(l).] Since the above does not affect the remaining terms in the rate expression of Pound et al., the details are referred to their paper. The resulting nucleation rate is If the experimental AGV and T values at some common value of are employed, a plot of vs T(ln C3/l + In p&apos;) should yield a straight line of slope k/B<p and intercept . The corresponding plots for / = 1 nucleus per sq cm sec and C3 = 1018 are shown in Figs. 1 and 2 for cadmium on copper1 and sodium on CsCl2 and the values of obtained therefrom are entered in Table I. It is apparent that the data yield reasonable straight lines with about the same scatter as found using the equation of Pound et al. When the configuration of minimum free energy for a nucleus is a circular monatomic layer, the standard free energy of formation is

Jan 1, 1963

University of Alabama University, Alabama Mining and Metallurgical Society WILLIAM R. HIGGS, President ROBERT E. MEAD, Secretary J. R. CUDWORTH, Faculty Sponsor MILTON H. FIBS, Counselor University of Arizona Tucson, Arizona Miners&apos; Society LEE BLESSING, President R. W. CORY, Secretary E. P. MATHEWSON, Faculty Sponsor B. R. HATCHER, Counselor University of California at Los Angeles Los Angeles, California Student Chapter, A.I.M.E. ARCHER WARNE, President ROBERT JOHNSTON, Secretary E. K. SOPER, Faculty Sponsor EMILE HUGUENIN, Counselor Colorado School of Mines Golden, Colorado Student Chapter, A.I.M.E. J. Ross REED, President ANDREW PERRY, JR., Secretary J. BURNS READ, Faculty Sponsor A. W. NEWBERRY, Counselor

Jan 1, 1936

Domestic: Middle West-,11.. B. Newcombe Eastern District-J. French Robinson1 Kansas-Henry A. Ley 2 Oklahoma-Henry A. Ley 3 Texas, except Gulf Coast and Panhandle-M. G. Cheney 5 Texas Panhandle-W. E. Hubbard and H. E. Crum 6 Gulf Coast-L. P. Teas 7 South Arkansas, North Louisiana and Mississippi-H. K. Shearer 8 Foreign Mexico-V. R. Garfias and C. 0. Isakson 9 Canada-Line M. Farish 10 Venezuela-C. W. Hamilton 10 Colombia-J. T. Duce 12 Peru-O. B. Hopkins 12 Trindad-Williaim J. Millard 13 Dutch East Indies-Fred B. Ely 13 Rumania-I. I. Gardescu . .. . 14 India-Eric J. Bradshaw 14

Jan 1, 1931

E. T. Turkdogan (British Iron & Steel Research Assoc., London, England)—I would like to suggest a different method for the treatment of the authors&apos; data on the Si-0 equilibrium in liquid iron. Because the activity coefficient of silicon dissolved in iron is influenced by the concentration of silicon as well as that of oxygen, the equilibrium constant K2 of reaction 2 becomes a function of metal composition, and, as shown in Fig. 1, a plot of log KP1 at 1600°C against the weight percent of silicon gives a smooth curve. A similar curve is obtained when log Kzl is plotted against the oxygen content of iron. Before

Jan 1, 1955

New York Meets first Wednesday after first Tuesday of each month. DAVID H. BROWNE, Chairman. PERCY E. BARBOUR, Vice-Chairman. A. D. BEERS, Secretary, 55 Wall St., New York, N. Y. C. A. BOHN, Treasurer. Boston Meets first Monday of each winter month. W. E. C. EUSTIS, Chairman. R. L. AGASSIZ, Vice-Chairman. E. E. BUGBEE, Secretary-Treasurer, Mass. Inst. of Technology, Boston, Mass. ALBERT SAUVEUR, H. L. SMYTH. Columbia Holds four sessions during year. Annual meeting in September or October. STANLY A. EASTON, Chairman. FREDERIC KEFFER. Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. D. C. LIVINGSTON. FRANK A. ROSS.

Jan 10, 1916

New York Meets first Wednesday after first Tuesday of each month. L. W. FRANCIS, Chairman, WILLARD S. MORSE, Vice-Chairman,. THOMAS T. READ, Secretary, Woolworth Bldg., New York, N. Y. P. A. MOSMAN, Treasurer. LOUIS D. HUNTOON. - WILLIAM A. POMEROY. Boston Meets first Monday of each winter month. HENRY L. SMYTH, Chairman. ALFRED C. LANE, Vice-Chairman. HENRY A. WENTWORTH, Secretary-Treasurer, 60 India St., Boston, Mass. ROBERT H. RICHARDS, ALBERT SAUVEUR. Columbia Holds four sessions during year. Annual meeting in September or October. FRANK A. ROSS, Chairman. RUSH J. WHITE, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. FREDERIC KEFFER, FRANCIS A. THOMSON.

Jan 5, 1915

New York Meets first Wednesday after first Tuesday of each month. DAVID H. BROWNE, Chairman, JOHN H. JANEWAY, Vice-Chairman. F. E. PIERCE. Secretary, 35 Nassau St., New York, N. Y. P. A. MOSMAN, Treasurer. LEWIS W. FRANCIS. Boston Meets first Monday of each winter month. HENRY L. SMYTH, Chairman. ALFRED C. LANE, Vice-Chairman. HENRY A. WENTWORTH, Secretary-Treasurer, 60 India St., Boston, Mass. ROBERT H. RICHARDS, ALBERT SAUVEUR. Columbia Holds four sessions during year. Annual meeting in September or October. FRANK A. ROSS, Chairman. RUSH J. WHITE, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. FREDERIC KEFFER, FRANCIS A. THOMSON.

Jan 8, 1915

New York Meets first Wednesday after first Tuesday of each month. DAVID H. BROWNE, Chairman. PERCY E. BARBOUR, Vice-Chairman. A. D. BEERS, Secretary, 55 Wall St., Now York, N. Y. C. A. BOHN, Treasurer. Boston Meets first Monday of each winter month. W. E. C. EUSTIS. Chairman. R. L. AGASSIZ, Vice-Chairman. E. E. BUGBEE, Secretary-Treasurer, Mass. Inst. of Technology, Boston, Mass. ALBERT SAUVEUR, H. L. SMYTH. Columbia Holds four sessions during year. Annualmeeting in September or October. STANLY A. EASTON,- Chairman FREDERIC KEFFER,-Vice-Chairman: LYNDON K. ARMSTRONG, Secretary-Treasurer, P.O. Drawer 2154, Spokane, Wash. D. C. LIVINGSTON, FRANK A. ROSS.

Jan 10, 1916

New York Meets first Wednesday after first Tuesday of each month. DAVID H. BROWNS Chairman. JOHN H. JANEWAY, Vice-Chairman. F. E. PIERCE, Secretary 35 Nassau St., New York, N. Y. P. A. MOSMAN, Treasurer. LEWIS W. FRANCIS. BENJAMIN B.. LAWRENCE. Boston Meets first Monday of each winter month. HENRY L. SMYTH, Chairman. ALFRED C. LANE, Vice-Chairman. HENRY A. WENTWORTH, Secretary-Treasurer, 60 India St., Boston, Mass. A. H. EUSTIS, F. G. STANTIAL. Columbia Holds four sessions during year. Annual meeting in September or October. STANLY A. EASTON, Chairman. FREDERIC KEFFER, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. D. C. LIVINGSTON, FRANK A. ROSS.

Jan 5, 1916

New York Meets first Wednesday after first Tuesday of each month. DAVID H. BROWNE, Chairman. PERCY E. BARBOUR, Vice-Chairman. A. D. BEERS, Secretary, 55 Wall St., New York, N. Y. C. A. BOHN, Treasurer. Boston Meets first Monday of each winter month. W. E. C. EUSTIS, Chairman. - R. L. AGASSIZ, Vice-Chairman E. E. BUGBEE, Secretary-Treasurer, Mass. Inst. of Technology, Boston, Mass. ALBERT SAUVEUR, H. L. SMYTH. Columbia Holds four sessions during year. Annual meeting in September or October. STANLY A. EASTON, Chairman. FREDERIC KEFFER, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. D. C. LIVINGSTON. FRANK A. ROSS.

Jan 12, 1916

By James H. Neisz, Gregory P. White

This paper discusses the development of surface coal mine planning programs for a microcomputer. A set of seven programs which were originally written for a large mainframe computer are described. The problems encountered in converting these programs to a micro with 52K of available core storage are discussed. A program for economic evaluation which is currently running on the micro is described and plans to convert other programs to the micro are detailed. In addition, we explain the microcornputer system we have assembled and give the rationale for each component. Problems we have encountered with this system are described for the benefit of others who may follow our path.

Jan 1, 1983

New York Meets first Wednesday after first Tuesday of each month. DAVID H. BROWNE, Chairman. PERCY E. BARBOUR, Vice-Chairman. A. D. BEERS, Secretary. 55 Wall St., New York, N. Y. C. A. BOHN, Treasurer. Boston Meets first Monday, of each winter month. W. E. C. EUSTIS, Chairman. R. L. AGASSIZ, Vice-Chairman. E. E. BUGBEE, Secretary-Treasurer, Mass. Inst. of Technology, Boston, Mass. ALBERT SAUVEUR, H. L. SMYTH. Columbia Holds four sessions during year. Annual meeting in September or October. STANLY A. EASTON, Chairman. FREDERIC KEFFER, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. D. C. LIVINGSTON, FRANK A. ROSS.

Jan 9, 1916