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By R. M. S. Häggblad

The article deals with stabilisation and regeneration of Ce02 and Ce02/Zr02 based Pt water gas shift catalysts, subject to high initial deactivation. The reaction gas species effect on the catalyst deactivation was investigated by H2-TPR. Activity measurements enabled the effect of different promoters, some added to the Ce02 based catalysts and some to the Ce02/Zr02 based Pt catalysts, to be investigated. The catalysts were also characterised by BET and CO-TPR. Deactivated catalysts activity was restored by using various regeneration methods. Of the two selected carriers the Ce02/Zr02 based Pt catalyst showed the highest resilience to deactivation. For the two different carriers, Ce02 and Ce02/Zr02, Wand Re were the best promoters when the catalyst was subject to deactivation. Experiments with Hr TPR indicate a fast initial change in the platinum oxides concentration and composition. The CO-TPR was used to make conclusions about the various regeneration effects of water and oxygen on the catalyst. Finally it is suggested that not one deactivation mechanism is possible and which mechanism that dominates is dependant on the catalyst and the reaction gas composition.

Jan 1, 2005

By Eric A. Nordhausen

A good deal of dialogue has been published and voiced concerning one mining regulation or another, that, according to those raising the issues, in effect shuts down or drastically reduces mine and/or mill reduction. The objective of this discussion is to there fore synthesize the various regulations affecting the uranium mining industry and attempt to realistically assess the extent of impact to yellowcake production - on both an individual and collective basis. Emphasis is placed on the later or newer permitting requirements under the Mill Tailings Act, Underground Injection Control Program, the Consolidated Permit Program, and the Resource Conservation and Recovery Act (RcRA).

Jan 1, 1980

By H. M. Howe

§ 24. Introduction.—This paper discusses the chief existing data as to the temperature, in iron-carbon alloys, of Ae3, the upper limit of the transformation range when in equilibrium, as distinguished from Ac3, the temperature at which the end of the transformation is noted in heating up, and from Ar3, that at which its beginning is noted in cooling down. The former is in fact carried above Ae3 and the latter below Ae3 by lag. I touch incidentally on the influence of manganese on Ae3 (§ 29, p. 614). The sections, tables, and illustrations are numbered consecutively with those in the accompanying papers by Howe and Levy on Determination of the Position of Ae3 in Carbon-Iron Alloys, and by Burgess, Crowe, and Rawdon on Thermal and Microscopical Examination of Professor Howe's Standard Commercial Steels, to which the present paper forms a sequel. § 25. The contradictoriness of our present evidence is shown by grouping it together in Fig. 14. For instance, both Goerens and Meyer (Series 2) and Meuthen (Series 12) used practically stationary temperature, and thus reduced the influence of lag very greatly; yet Ae3 for 0.32 carbon steel according to the former investigators is 894", but according to Meuthen it is at or below 770°, a discrepancy of 124" or more. In view of our ability to measure these high temperatures within a few degrees, the existence of such a discrepancy is as unwelcome as it seems needless. I attack the thankless task of bringing some order out of this chaos. In Part 11. (§§ 29 to 39) I consider the chief causes of error. In Part III. (§§ 40 to 48) I apply certain corrections to some of the existing data, review those data, weight them, and calculate a prob-

Jan 1, 1914

By George R. Ensminger, E. Heaton Hemingway

During the past year, the Watertown Arsenal has been interested in the occluded gas and oxide content of certain ordnance steels in order to determine, if possible, whether some of the peculiar failures in their physical properties might not be traced to these causes. For the purpose of best accomplishing a study of this nature, it was decided to heat the various samples of steel in a vacuum for definite periods of time at high temperatures and carefully examine the quantity and composition of the gases evolved. By the use of a fused quartz tube fitted with a water-cooled, ground-glass stopper, it was possible to maintain a vacuum at a temperature of 1000" C. for 10 hr. without perceptible leakage being evidenced as measured by a McLeod gage. The silica tube was connected with an evacuating system so constructed that the volatilized gases could be removed from time to time and a low vacuum of 0.0002 to 0.0010 mm. of mercury continuously maintained. At no time during the period of heating or in the removal of the gases did the evacuated system come in contact with rubber stoppers or any rubber connections, making contamination from such a source, impossible. In other words, the only volatile products that could be: obtained must necessarily have come from the steel itself or from the glass and fused quartz system or from the mercury used as a sealing agent. In the carlier experiments, the steel treated was in the form of turnings, but this practice was discarded because the weight's of the turnings before and after being heated were widely inconsistent,, even when taken from the same piece of steel. This discrepancy developed largely through variation in the amount of metal volatilized with the gases; this metal could always be seen in the form of a ring where it condensed in the cooler portion of the tube in either the amorphous or crystalline condition. Because of the frequency in occurrence and the variation in the manner of deposition, this material was roughly analyzed and found to consist for the most part of iron. At the same time two samples of steel that had been

Jan 1, 1922

By E. Heaton Hemingway, George R. Ensminger

During the past year, the Watertown Arsenal has been interested in the occluded gas and oxide content of certain ordnance steels in order to determine, if possible, whether some of the peculiar failures in their physical properties might not be traced to these causes. For the purpose of best accomplishing a study of this nature, it was decided to heat the various samples of steel in a vacuum for definite periods of time at high temperatures and carefully examine the quantity and composition of the gases evolved. By the use of a fused quartz tube fitted with a water-cooled, ground-glass stopper, it was possible to maintain a vacuum at a temperature of 1000" C. for 10 hr. without perceptible leakage being evidenced as measured by a McLeod gage. The silica tube was connected with an evacuating system so constructed that the volatilized gases could be removed from time to time and a low vacuum of 0.0002 to 0.0010 mm. of mercury continuously maintained. At no time during the period of heating or in the removal of the gases did the evacuated system come in contact with rubber stoppers or any rubber connections, making contamination from such a source, impossible. In other words, the only volatile products that could be: obtained must necessarily have come from the steel itself or from the glass and fused quartz system or from the mercury used as a sealing agent. In the carlier experiments, the steel treated was in the form of turnings, but this practice was discarded because the weight's of the turnings before and after being heated were widely inconsistent,, even when taken from the same piece of steel. This discrepancy developed largely through variation in the amount of metal volatilized with the gases; this metal could always be seen in the form of a ring where it condensed in the cooler portion of the tube in either the amorphous or crystalline condition. Because of the frequency in occurrence and the variation in the manner of deposition, this material was roughly analyzed and found to consist for the most part of iron. At the same time two samples of steel that had been

Jan 1, 1922

By C. H. Samans, G. F. Tisinai, J. K. Stanley

The addition of nitrogen (0.10 to 0.20 pct) to Fe-Cr-Ni alloys of simulated commercial purity results in a real displacement of the u phase boundaries to higher chromium contents. The effect is small for the (Y + s)? boundary, but is pronounced for the (y + a +s)/(y + a) boundary. Although there is an indication of an exceptionally large shift of the n boundaries to higher chromium contents, especially in steels with nitrogen over 0.2 pct, the major portion of this apparent shift results from the fact that carbide and nitride precipitation cause "chromium impoverishment" of the matrices. The effect of combined additions of nitrogen and silicon to the Fe-Cr-Ni phase diagram is demonstrated also. Nitrogen can nullify the effect of about 1 pct Si in shifting the (y + o)/? phase boundary to lower values of chromium at all nickel levels from 8 to 20 pct. NItrogen can nullify this U-forming effect of about 2 pct Si at the 8 pct Ni level, but not at the 20 pct Ni level. The alloys studied were in both the cast and the wrought conditions. There are indications that the u phase forms more slowly in the cast alloys than in the wrought alloys if both are in the completely austenitic state. The presence of 6 ferrite in the cast alloys accelerates the formation of U. Cold working increases the rate of o formation in both cast and wrought alloys. THE major improvement in Fe-Cr-Ni austenitic alloys in recent years has been in the addition or removal of minor alloying elements to facilitate better control of corrosion resistance, sensitization, and heat resistance. One shortcoming of the austenitic Fe-Cr-Ni alloys, which never has been completely circumvented, is their propensity toward u formation. In the AISI-type 310 (25 pct Cr-20 pct Ni) and type 309 (25 pct Cr-12 pct Ni) steels, sufficient amounts of u phase can form, if service or treatment is in a suitable temperature range, to cause severe embrittlement. Also, there is a growing conviction that this phase may be contributory to some unexpected decreases in the corrosion resistance of certain of the 18 pct Cr-8 pct Ni-type steels. The present paper discusses the effect of nitrogen additions on the location of the (r+u)/d and the (y+a+u)/(y+a) phase boundaries in the ternary Fe-Cr-Ni system, for cast and wrought alloys of simulated commercial purity, and in similar alloys containing up to about 2.5 pct Si. The objective is to define compositional limits for alloys which will not be susceptible to u formation when used near 1200°F (650°C). An excellent review of the early studies of the u phase in the Fe-Cr-Ni system has been compiled by Foley.1 Rees, Burns, and Cook2 have determined a high purity phase diagram for the ternary system, whereas Nicholson, Samans, and Shortsleeve3 are- stricted themselves to a portion of the simulated commercial-purity phase diagram. Both groups of investigators show almost an identical position for the commercially significant (y+u)/y phase boundary. Further comparison of the work of the two groups indicates that, below the 8 pct Ni level, the commercial alloys have a decidedly greater propensity toward u formation than the high purity alloys. The two groups of workers agreed that both the AISI-type 310 (25 pct Cr-20 pct Ni) and the type 309 (25 pct Cr-12 pct Ni) steels are well within the (y+~) region and that the 18 pct Cr-8 pct Ni-type alloys straddle the U-forming phase boundaries. Nicholson et al.3 showed, in addition, that these boundaries shift toward lower chromium contents if greater than nominal amounts of silicon or molybdenum are added. The effect of nitrogen on the location of the s phase boundaries in the Fe-Cr-Ni system has not been known with any certainty. In 1942, an approach to this problem was made by Krainer and Leoville-Nowak,' but at that time they apparently were unaware of the slow rate of s formation in strain-free samples and aged their samples for insufficient times, e.g., 100 hr at 650°C (1200°F) and 800°C (1470°F). For this reason, it would be expected that their (y+ u) /y boundary would be shifted toward lower chromium contents (restricted ?-field) when equilibrium conditions were approximated more closely. Procedure for Studying the Alloys The alloys used were prepared in the following way: Heats of 200 lb each were melted in an induction furnace. A 5 lb portion of each heat was poured into a ladle containing an aluminum slug for de-

Jan 1, 1955

By J. L. Shultz

The Bureau of Mines extended its investigation of methanation catalysts. The noble metals (platinum, palladium, ruthenium, rhodium, osmium) and rhenium), molybdenum, and tungsten were tested in hydrogenations of carbon monoxide and carbon dioxide at 21 atmospheres in a temperature range between 200° and 600° C. From the 8 metals studied) 25 catalysts represent 5 catalyst types were prepared and tested. The impregnated 0.5-percent-ruthenium catalyst proved to be the most active and versatile of all the catalysts produced. Tungsten and the noble metals other than ruthenium were low in activity and usually required temperatures above 500° C for appreciable production of hydrocarbons. Molybdenum was moderate in activity, but further improvement in molybdenum catalysts seems possible.

Jan 1, 1967

By H. N. Eavenson

Prior to 1907 nearly all coke was made in beehive ovens, and most of the gas produced was made in the old-style gas retorts, and while there were a few coke plants in southern West Virginia, southwest Virginia and Kentucky operating on high-volatile coals the proportion of the total product made by them was small and usually was used locally. The greater part of the coke made, and the coal gas produced, came from the Pittsburgh seam of western Pennsylvania and northern West Virginia, which was then regarded as the standard coking and gas coal of the country, and the best coal available anywhere for these purposes. With the advent of the byproduct oven and the building of coke plants at the furnaces, the restriction of the use of one grade of coal for making coke was removed and the use of mixtures of low-volatile and high-volatile coals began. The change in the locations of the coke plants removed the necessity of using Connellsville coal and also made sources of gas available to the public utilities other than of their own manufacture. Most of the first oven plants were built at points distant from the Connellsville region and this afforded an opportunity for the use of coals from the southern Appalachian fields, which were then at approximately equal distances from the ovens. Since that time development has been made on a number of seams of coal of great purity in southern West Virginia, southwestern Virginia and eastern Kentucky, which have been largely used for gas, cokemaking and metallurgical purposes where low amounts of ash, sulfur and phosphorus are determining factors. These coals are much lower in the objectionable elements than most of the coal shipped from the Pittsburgh seam, or than any northern coal, and when blended with low-volntile cod produce coke in byproduct ovens that is not excelled for any purpose by any coal mined in this country, and is equaled very seldom. Coal from several of these scams is shipped in great quantities without beneficlation and is lower in ash and sulfur than any but the best washed product from the Pittsburgh seam in the north. The writer has made a study of these coals to ascertain their relative qualities and the areas and reserves of coal available in each of them. No attention has been paid to the coals of Alabama, which do not compete with any of these coals, and no coal of equivalent quality is found in

Jan 1, 1934

By George H. Holmes

Beryllium deposits in the northern Virgin Mountains , Clark County , Nev . , and Mohave County , Ariz . , about 70 miles northeast of Las Vegas , were investigated by the Bureau of Mines . The investigation indicated a widespread occurrence of beryllium- bearing pegmatites within an extensive belt of mica - schist . Several deposits with significant beryllium mineral concentrations were encountered . Only a few of the samples analyzed contained more than 1 percent beryllium oxide ( BeO ) ; in many of the samples , no beryllium was reported . The average tenor of samples from the more important occurrences was 0.25 percent BeO . Chrysoberyl is the predominant beryllium mineral in the pegmatite sills ; beryl predominates in the more massive bodies . Minute quantities of cesium and lithium minerals also occur , but no columbium , tantalum , or other rare minerals were found . Ore dressing tests on a composite sample containing 0.28 percent BeO which was representative of the pegmatite sills , indicated an 85 percent recovery of the chrysoberyl ( 70 percent recovery of total BeO ) by gravity concentration in a concentrate containing 17.6 percent BeO .

Jan 1, 1964

By Qingyu Deng, Shiwei Ma, Wang Hua, Guibao Qiu

"The flow properties of the blast furnace slag bearing high TiO2 at high temperature like the viscocity may change a lot due to the formation of the carbonitride inside, causing serious problems on the separation between the metal and the slag. Therefore, the critical condition of the formation of Ti(C,N) in blast furnace is vital importance for the ironmaking process with iron ore bearing titania. In this study, the formation of Ti(C,N) in blast furnace and the influences of various factors on the Ti(C,N) formation are investigated by FactSage. It is found that the mass of Ti(C,N) would reach the maximum at 1480 oC, and the product is mainly TiN below 1620 oC, while it is mainly TiC above 1620oC. The order of the factors by the importance from strong to weak was: temperature, the content of TiO2 in slag, basicity of slag, the content of MgO and Al2O3.IntroductionThe titanium dioxide (TiO2) in iron ore bearing titania will be partly reduced by carbon to titanium carbonitride (Ti(C,N)) in blast furnace, causing serious problems on the separation between the metal and the slag because of the change of flow property. Therefore, the critical condition of the formation of Ti(C,N) in blast furnace is vital importance for the ironmaking process, especially for the smelting of iron ore bearing titania. Extensive experimental data in regard to the formation of Ti(C,N) has been reported in numerous papers[1-6]. However, only some discrete data can be obtained by experiment, and it is difficult to detect the mass of Ti(C,N) in slag. In addition, the experiment is difficult to be proceeded when the temperature is above 1600oC. Therefore, it is very difficult to make clear the critical condition of the formation of Ti(C,N) by experiment."

Jan 1, 2012

By Albert E. Long

During the summer and fall of 1948 the Bureau of Mines, in cooperation with the U. S. Geological Survey, conducted 6xperiments in diamond core drilling in the Phosphoria formation in southeastern Idaho and southwestern Wyoming. Nearly all of the diamond core drilling in the Phosphoria formation has been done by mining companies interested in finding and developing phosphate-bearing beds amenable to stripping. The recovery of sludge; and enough core (usually 30 to 60 percent) to identify certain marker beds produced by current drilling practices meets both the primary requirement of mining companies in determining depth of overburden and their secondary need to determine the phosphate content of relatively thick minable units whose general composition and nature are already fairly well established.

Jan 1, 1949

Mineral resource development activities impact the health and well-being of many people, from workers, to families and surrounding communities. In the decade up to 2010, mining revenues increased from 6% to 14% of Australian GDP, and minerals contributed 55% of total exports, with a growth in mining employment from 1% to 1.7% of the national workforce (Connolly and Orsmund, 2011). The growth in Australia?s minerals operations is mostly located in remote areas, or in rural communities with a limited population. As a result, operations have increasingly implemented long distance commuting (LDC) programs, often called ?fly-in, fly-out? (FIFO) and ?drive-in, drive-out? (DIDO), as a staffing strategy to meet rapid industry growth in locations with limited local populations. The rapid expansion of the minerals industry has resulted in considerable public debate about the benefits and costs to all sectors of Australian society. In response to the concerns of constituencies from many parts of Australia, the Minister for Regional Australia, Regional Development and Local Government, The Hon Simon Crean MP, asked the House Standing Committee on Regional Australia on Tuesday 23 August 2011 to inquire into and report on the use of ?fly-in, fly-out? (FIFO) and ?drive-in, drive-out? (DIDO) workforce practices in Regional Australia. The recently published report highlights the national interest and the diverse opinions about this practice in Australia. Resource extraction companies have developed several options to meet the accommodation requirements of their long distance commuting workforce. In this paper, initial results are reported from an ongoing survey of FIFO (and other non-residential) resource industry workers (n = 286) in the Australian resource extraction industries. The purpose of this study was to better understand how accommodation arrangements may impact on the health, wellbeing and job satisfaction of non-resident workers; and to attempt to find a relationship between different accommodation variables and workforce wellbeing and retention. In doing this it investigates evidence for the linkage between accommodation factors, hours of work, health, well-being, job satisfaction and job retention in the LDC work force.

Aug 1, 2013

By E. H. Hamilton

THE furnace on which the following investigation was based had dimensions 48 by 160 in., and was in continuous operation during the three days of the test. The average charge consisted of PER CENT. LB. PER HOUR Bed ore?14.5?2,980 Roast from Dwight-Lloyds?44.5?9,160 Siliceous ore?3.5?720 Iron flux?2.1?430 Battery plates?0.5?103 Lime rock?23.9?4,925 Briquettes?4.0?825 Scrap iron?2.1?430 M. P. slag?4.2?865 L. P.speiss?0.7?142 Total 100.0 THE furnace on which the following investigation was based had dimensions 48 by 160 in., and was in continuous operation during the three days of the test. The average charge consisted of PER CENT. LB. PER HOUR Bed ore?14.5?2,980 Roast from Dwight-Lloyds?44.5?9,160 Siliceous ore?3.5?720 Iron flux?2.1?430 Battery plates?0.5?103 Lime rock?23.9?4,925 Briquettes?4.0?825 Scrap iron?2.1?430 M. P. slag?4.2?865 L. P.speiss?0.7?142 Total?100.0?20,580

Jan 1, 1924

By D. G. Russell

Two techniques have been developed with which the applicability of pressure build-up analyses can be extended to include pressure data which previously have been considered virtually unusable. One of the interpretation methods makes possible the analysis of pressure build-up performance during the wellbore fill-up or after production period which occurs soon after a well is closed in. The other technique is an extension of a method for analyzing pressure build-up performance during the late-time portion of the pressure build-up which occurs after boundary eflects first begin to alter the shape of a conventional pressure build-up curve. With both of these methods it is possible to obtain estitnates of the kh product, the skin factor and the reservoir pressure. In addition, with the late-time analysis technique it is possible to obtain an estimate of the contributory drainage volume of the well being tested. This means that in some cases a check on reservoir limit test and (or) material-balance calculations can now be obtained from pressure build-ups. Both methods are slightly more time-consuming than conventional pressure build-up analysis methods because trial-and-error plots of pressure data must be made. The late-time method for analysis of pressure build-ups is in principle applicable to the late-time portion of a two-rate flow test or a pressure drawdown test. The interpretation formulas and procedures for these types of tests are also outlined. In these cases, as with pressure build-ups, it is significant that an estimate of the contributory pore volume is also obtained. On the basis of limited experience with the new techniques, it appears that satisfactory estimates of the kh product, skin factor, reservoir pressure and, for late-time analysis, contributory drainage volume can be obtained. INTRODUCTION The analysis of bottom-hole pressure build-up behavior in closed-in wells has been a a subject of interest in petroleum engineering circles for many years. In fact, few other subjects have received as much attention as pressure buildup analysis methods have. The cause for this interest is essentially twofold in nature. First, the pressure behavior of a well can normally be measured with a reasonably high degree of accuracy so that good data for analysis can be obtained. Secondly, over a fairly wide range of operating conditions, valuable information as to the quality of the reservoir rock and completion efficiency of the well can be obtained at a nominal cost. In recent years, numerous papers have been prepared on the effects of various operating conditions and reservoir heterogeneities on pressure buildup behavior. Very little work has been done, however, on extension of pressure build-up analysis methods to those pressure data which are not amenable to analysis by the present methods. The theory upon which the analysis of shut-in bottom-hole pressure build-up data is based is derived from the solution of the radial flow equation for a slightly compressible fluid for constant-rate conditions. It requires that the well be closed in for a sufficient period of time to obtain a clearly defined linear portion on the plot of observed bottom-hole pressure vs log (t + ?t)/ ?t (where At is shut-in time, and t is producing time to the instant of shut-in). From the slope of the plot and other normally obtainable data, the formation permeability, the well damage or skin factor, and the reservoir pressure at infinite shut-in time (if the reservoir were infinite) can be estimated. The successful application of this procedure depends on being able to recognize the straight-line section on the basic pressure build-up plot. The presently used pressure build-up interpretation theory also assumes that a well is closed in at the sand face and that no production into the well occurs after shut-in. In practice, of course, the well is closed in at the surface, and inflow into the well continues until the well fills sufficiently to transmit the effect of closing-in to the formation. This adjustment period is commonly referred to as the "afterproduction" or "fill-up" portion of the pressure build-up. During the period that the well fill-up effect is most pronounced, the basic pressure build-up plot is nonlinear. At later shut-in times after the effects of a drainage boundary have been felt at the well, deviation from the straight-line behavior of the pressure build-up plot also results. In many cases either of these effects or a combination of both can make the straight-line portion on the pressure build-up plot difficult to recognize. Obviously, an extension of pressure build-up analysis methods to include the afterproduction period and the period in which boundary effects are being felt would be desirable and might render valuable pressure data which for years have been considered virtually unusable. The principal reference of note concerning pressure buildup analysis during the afterproduction period is a paper by Gladfelter, Tracy and Wilsey.1 In the approach of these authors it is necessary to measure the rate of influx into the well during the afterproduction period. This is done through sonic measurements or through measurement of tubing-head and casing-head pressures simultaneously with

Jan 1, 1967

By Robert W. Ageton

The Bureau of Mines is currently conducting a comprehensive study to evaluate all aspects of recovering gold from large, low-grade deposits in the Golden Sunlight area, Whitehall mining district, Jefferson County, Mont. Prior to World War II this area produced significant quantities of gold. The study includes geologic mapping, diamond drilling, assaying, computer analysis of assay data, metallurgical research and ore testing, mine and mill planning, and an economic evaluation of all factors bearing on the establishment of a producing gold mine. Preliminary evaluation of the deposit indicates about 31 million tons of submarginal gold resources. American Exploration and Mining Co. (AMEX) has assisted the Bureau in this project by providing drill site preparation, control assays, and geological aid for the Bureau's exploration work and by furnishing comprehensive assay information of the property and copies of base and geologic maps. This report presents the geology and mining history of the area, together with a summary of Bureau work in progress.

Jan 1, 1969

By Atul Kurnar

In the present research a two-cell polymer electrolyte membrane fuel cell stack (PEMFCS) with SS-316 bipolar plates has been tested. Different flow field designs were studied and a modified multi-parallel channel design is proposed. The stack is stable within ±3 mV even after 1000 hours of continuous operation, indicating efficient water management and effective removal of any metal ions from the stack. Also no iron is detected in membrane electrode assembly (MEA) by EDAX analysis after 1000 hours of cell operation. Results indicate that high operating pressures beyond 138 kPa didn't significantly increase the performance of cell, however added much to the pressurization cost of the system. Tests at different temperatures showed that at temperatures below 80°C, external humidification could be completely removed. The prototype stack is also tested under variable load conditions simulating highway-driving schedule. The experimental efficiency of PEMFCS is 48%, which is in good agreement with the model predicted efficiency of 53.8 %. Results show that 59% of the total losses are due to ohmic polarization in the cell. Further analysis on applications of the stack in automotive transportation system is in progress.

Jan 1, 2002

By Charles Berkey

CONTENTS PAGE C. P. Berkey-Responsibilites of the Geologist in Engineering Projects (with discussion) 4 Kirk Bryan-Problems Involved in the Geologic Examination of Sites for Dams 10 0. E. Meinzer-Relation of Ground-water Conditions to Leakage of Reservoirs (with discussion) 19 Charles Terzaghi-Effect of Miner Geologic Details on the Safety of Dams (with discussion) 31 G. H. Matthes-More and Better Geologic Data for Use in Hydraulic Projects (with discussion) 47 L. W. Fisher and R. D. Ohrenschall-Geologic Examination of Dam Sites in the Tennessee and Cumberland River Basins 60 C. K. Wentworth-The Geology of Dam Sites (with discussion) 78 L. C. Glenn-The Geology of Dams and Reservoirs 97 H. T. Stearns-Success and Failure of Reservoirs in Basalt (abstract) 111

Jan 1, 1929

There is very little in Australian mining law that sets out the rights of mining tenement and exploration licence holders as against other parties who wish to carry out ground or aerial surveillance over those areas.There have already been several legal actions arising out of this lack, and more can be expected as the public places more rigorous constraints on corporate and individual behaviour. Field personnel, who are mainly fairly junior and less experienced, are entitled to some guidance from the minerals industry, guidance which up to now appears to have been either lacking or covering such a wide range of standards from corporation to corporation as to be virtually useless.Because each State writes its own laws there is no consistency, and the laws generally are lagging behind developments in the industry. In particular, the practice of granting mining tenements for sporadic exploration, a practice that is a leftover from much earlier mining law, has dotted the Australian continent with unattended and unmarked or poorly marked tenements that are difficult to find but confer on the holder prior rights to the minerals under them. Entry onto those areas in most jurisdictions is an offence and their existence compromises the efforts of regional explorers.This clearly unsatisfactory situation requires remedying, which is the purpose of these proposals. A more systematic approach to the granting of reconnaissance, regional and detailed exploration, mining, and retention rights will eliminate much of the problem. For the rest, a code of practice needs to be adopted as soon as possible.

Jan 1, 1996

By Luis de Montreul

El conocimiento de los controles mineralógicos, tipos de ocurrencias y otras características mineralógicas de los depósitos auríferos permite plantear una adecuada exploración geológica-minera y seleccionar un óptimo tratamiento metalúrgico. Por ello, se busca establecer la relación entro el oro y determinados minerales metálicos y no metálicos para obtener una mejor recuperación de este elemento valioso. En ese sentido, el presente texto presenta ejemplos de controles mineralógicos en seis yacimientos aurífero de cinco Fajas mineralizadas del Perú.

Jul 1, 1987

By J. Pasini

The Bureau of Mines has investigated novel methods of stimulating petroleum production from reservoirs in the Appalachian Region. An important consideration in applying stimulative production methods is the control and removal of solid precipitates from the boreholes of production wells. Where paraffin-base crude oils are produced, as in the Appalachian Region, the accumulation of paraffin may be particularly troublesome. Paraffin deposition is a major production problem that has confronted the petroleum industry for many years. Although considerable effort has been expended by industry and government, a suitable solution has not been found because of the individuality and complex nature of the deposits. Remedial methods used to prevent or remove paraffin fall generally into four classes: (1) Chemical, (2) physical, (3) operative, and (4) combination. Each class has many subclasses that apply to particular problems in different oil- producing areas. Recently, chemical inhibitors and the sonic pump have assisted operators in preventing and removing paraffin deposits. Because these methods are relatively new, their degree of application has not been completely evaluated.

Jan 1, 1963