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By T. E. Kihlgren, N. B. Pilling, E. M. Wise

Systematic data are presented on the relation of composition of nickel silvers to color, tarnish resistance, hardness and liquidus temperatures, for alloys containing up to 30 per cent nickel and 50 per cent zinc, further modified at certain nickel and zinc contents by 0 to 8 per cent of tin and 0 to 10 per cent of lead. Attention has also been directed, using a still more limited range of alloys, toward a study of tensile properties and such casting properties and characteristics as fluidity, shrinkage and pressure tightness. In some of these, rather broad ranges of composition are dealt with; in others, it has been expedient to focus attention on the Federal Specification 20 per cent nickel silver casting alloy, WWP-541. Introduction The demand for an alloy essentially white in color, which could be cast and worked by simple methods and which possessed strength and corrosion-resisting properties superior to the usual brasses, led to the discovery and early use of cupronickel alloys containing zinc, and sometimes tin, lead and other metals. This type of alloy was generally known as 'German silver until the war, when the term "Nickel Silver" became generally accepted. The element principally responsible for the white color of the alloy and for its strength and corrosion resistance is nickel, which may constitute from 8 to 30 per cent of the alloy. The functions of the other elements will be described later. The manifold uses of nickel silver are largely due to its color, corrosion resistance, ease of casting, fabrication, joining and rather moderate cost. In many instances the alloy is finished by grinding and polishing while in others it may be finished with a silver or nickel plus chromium plate. Electroplates applied to a nickel silver base behave more satisfactorily than those applied to the softer and less resistant alloys, and owing to the white color of the underlying metal the article will retain a pleasing appearance despite local failures of the plating.

Jan 1, 1935

By E. M. Wise, T. E. Kihlgren, N. B. Pilling

Systematic data are presented on the relation of composition of nickel silvers to color, tarnish resistance, hardness and liquidus temperatures, for alloys containing up to 30 per cent nickel and 50 per cent zinc, further modified at certain nickel and zinc contents by 0 to 8 per cent of tin and 0 to 10 per cent of lead. Attention has also been directed, using a still more limited range of alloys, toward a study of tensile properties and such casting properties and characteristics as fluidity, shrinkage and pressure tightness. In some of these, rather broad ranges of composition are dealt with; in others, it has been expedient to focus attention on the Federal Specification 20 per cent nickel silver casting alloy, WWP-541. Introduction The demand for an alloy essentially white in color, which could be cast and worked by simple methods and which possessed strength and corrosion-resisting properties superior to the usual brasses, led to the discovery and early use of cupronickel alloys containing zinc, and sometimes tin, lead and other metals. This type of alloy was generally known as 'German silver until the war, when the term "Nickel Silver" became generally accepted. The element principally responsible for the white color of the alloy and for its strength and corrosion resistance is nickel, which may constitute from 8 to 30 per cent of the alloy. The functions of the other elements will be described later. The manifold uses of nickel silver are largely due to its color, corrosion resistance, ease of casting, fabrication, joining and rather moderate cost. In many instances the alloy is finished by grinding and polishing while in others it may be finished with a silver or nickel plus chromium plate. Electroplates applied to a nickel silver base behave more satisfactorily than those applied to the softer and less resistant alloys, and owing to the white color of the underlying metal the article will retain a pleasing appearance despite local failures of the plating.

Jan 1, 1935

By C. E. Webber

The economical recovery of the valuable constituents from the effluent of gas-con-densate wells has developed into a problem of balancing the cost of recovery against the cost of compressing the residual gas back into the formation. A possible method of extracting the gasoline and distillate from the natural gas is by oil absorption at high pressures. In order to design and evaluate an absorption plant, fundamental data on the composition of the coexisting hydro- carbon vapor and liquid phases at various temperatures and pressures are essential. A review of the literature indicated that the necessary data for the design of such plants are lacking. The nearest approach to desired published data is that of Katz and Hackmuth,~ who experimentally deter-mined the composition of the coexisting vapor and liquid phases in a natural gas-crude oil system at pressures up to 3000 lb. per sq. in. and at temperatures from 40' to zoo°F. This paper presents the results of the experimental determination of the equilib-rium distribution of the hydrocarbons methane through hexane between natural gas and a typical absorber oil. The ranges of temperature and pressure chosen were from 33' to r8oUF. and from 100 to 5000 lb. per sq. inch. Materials The absorber oil was a typical naturally occurring, Straw-colored distillate that had previously been steam-distilled to an initial boiling point of 300 F. The physical and chemical properties, including the results of an Engler distillation, are presented in Table I. A large volume of this oil was obtained and it was used throughout the complete set of experiments. Table i.—Properties of the Absorption Oil Gravity .......................... . . 32.5' A.P.1. Molecular weight by benzene freezing- point depression.................. 183 Viscosity, poises; at 100°F........... 0.0a80 At 200°F...................... 0.0102 Composition, PeR Cent Aromatics........ 24.0 Naphthenes..... 36.7 unsaturates,Aromatics...... .I24.00.3 1 Parafins Naphthenes.....36.7 39.o EngLeR Distillation Per Cent /ncg. F. Per Cent Dez. P. Initial boilins rmint.. 300 I 60....... 523 5.................. 402 I 70....... 538 10.................. 421 180....... 557 20.................. 462 90....... 570 30.................. 480 1 95....... 623 40.................. 49 .................1 511 Residue, z .o per cent; loss, 0.3 per cent. See refrence I. The n-hexane was obtained from the Ohio Chemical and Manufacturing Co., Cleveland, Ohio. This liquid had a boiling range of from 149" to 152.6'F., with a density of 0.667 at 60°F. and a molecular weight of 85 by benzene freezing-point depression. The propane, isobutane, wbu-tane, isopentane and n-pentane were ob-ta,ined from the Philgas Department of the Phillips Petroleum Co. Certified analyses of these compounds showed their purity to be in excess of 99.5 per cent and they were riot further purified.

Jan 1, 1941

By C. E. Webber

The economical recovery of the valuable constituents from the effluent of gas-con-densate wells has developed into a problem of balancing the cost of recovery against the cost of compressing the residual gas back into the formation. A possible method of extracting the gasoline and distillate from the natural gas is by oil absorption at high pressures. In order to design and evaluate an absorption plant, fundamental data on the composition of the coexisting hydro- carbon vapor and liquid phases at various temperatures and pressures are essential. A review of the literature indicated that the necessary data for the design of such plants are lacking. The nearest approach to desired published data is that of Katz and Hackmuth,~ who experimentally deter-mined the composition of the coexisting vapor and liquid phases in a natural gas-crude oil system at pressures up to 3000 lb. per sq. in. and at temperatures from 40' to zoo°F. This paper presents the results of the experimental determination of the equilib-rium distribution of the hydrocarbons methane through hexane between natural gas and a typical absorber oil. The ranges of temperature and pressure chosen were from 33' to r8oUF. and from 100 to 5000 lb. per sq. inch. Materials The absorber oil was a typical naturally occurring, Straw-colored distillate that had previously been steam-distilled to an initial boiling point of 300 F. The physical and chemical properties, including the results of an Engler distillation, are presented in Table I. A large volume of this oil was obtained and it was used throughout the complete set of experiments. Table i.—Properties of the Absorption Oil Gravity .......................... . . 32.5' A.P.1. Molecular weight by benzene freezing- point depression.................. 183 Viscosity, poises; at 100°F........... 0.0a80 At 200°F...................... 0.0102 Composition, PeR Cent Aromatics........ 24.0 Naphthenes..... 36.7 unsaturates,Aromatics...... .I24.00.3 1 Parafins Naphthenes.....36.7 39.o EngLeR Distillation Per Cent /ncg. F. Per Cent Dez. P. Initial boilins rmint.. 300 I 60....... 523 5.................. 402 I 70....... 538 10.................. 421 180....... 557 20.................. 462 90....... 570 30.................. 480 1 95....... 623 40.................. 49 .................1 511 Residue, z .o per cent; loss, 0.3 per cent. See refrence I. The n-hexane was obtained from the Ohio Chemical and Manufacturing Co., Cleveland, Ohio. This liquid had a boiling range of from 149" to 152.6'F., with a density of 0.667 at 60°F. and a molecular weight of 85 by benzene freezing-point depression. The propane, isobutane, wbu-tane, isopentane and n-pentane were ob-ta,ined from the Philgas Department of the Phillips Petroleum Co. Certified analyses of these compounds showed their purity to be in excess of 99.5 per cent and they were riot further purified.

Jan 1, 1941

By Cotton R. E, Cox R

Digger Rocks is one of several nickel-bearing sulphide deposits localised within komaLiitic volcanics of the Forrestania Greenstone Bell within the Archaean YiIgam Block of Western Australia. Exploration and evaluation to April 1990 have delineated a resource, at a nominal cut-off grade of 0.5 per cent Ni, of 1.9 Mt at 1.1 per cent Ni within a lensoid sulphide body which strikes NW, dips 50°SW, and occurs at a depth of 30 - 110 m below surface. There has been no production from any of the Forrestania nickel deposits to-date. The deposit, comprising both disseminated and massive sulphides, has maximum dimensions of 400 m strike, 115 m vertically and 90 m true width. Generally the massive sulphides occur at the base of the disseminated sulphides, on or close to the base of the Digger Rocks dunite. The two main massive sulphide lenses have maximum dimensions of 120 m strike, 75 m vertically and 16 m true width (northern lens) and 60 m strike, 25 m vertically and 4 m true width (southern lens). The average grades of the massive and disseminated sulphides are 5.9 per cent i and 1.2 per cent i respectively. The massive sulphides generally have sharp hangingwall and fOOlwall contacts and display strong internal grade anisolropy.The massive sulphides are mainly within the supergene zone and consist of violarite, pyrite and marcasite. The disseminated sulphides are mainly within the primary zone and consist of pentlandite, pyrrholite, pyrite and minor chalcopyrite. Alteration zones, up to six in number, are complex in detail. The sulphides are capped by an average of 30 m of sub-economic, leached, siliceous, oxidised material.A genetic model for the deposit is described which places Digger Rocks in Category 2 (sulphides in large layered dunite bodies) of the latest classification of komatiitic nickel sulphide deposits in the Yilgam Block of Western Australia by Hill and Gole (1990).

Jan 1, 1992

By I J. Holland

Located in North West Queensland, XstrataÆs Mount Isa Copper Operations (MICO) is one of the largest underground mines in Australia with annual production exceeding six million tonnes of ore with average copper grades of three per cent. As at 30 June 2006, the Ore Reserve inventory totalled 87 Mt, with annual diamond drilling planned at >40 000 m in order to convert existing resources and test and define exploration targets. The role of the geology department within MICO is to collect, interpret and communicate relevant geological information to ensure the optimal extraction of ore. Routine underground inspections across multiple ore sources are undertaken and the information derived is then distributed to a range of professionals, operational personnel and management. The information is a æreal-timeÆ geological view for the stakeholders. Ongoing data collection and interpretation has developed a strong geological input to all mine planning processes within MICO. This has created strong synergies between mine planning professionals and a throughput benefit has been seen all the way to the concentrator. The MICO geological framework also provides avenues for a geological focus away from short-term production requirements, and as a result significant orebody scale observations and patterns have been realised that have led to an increase in the accuracy of geological and resource models. This has provided practical benefits for short-term scheduling and production, whilst enabling the realisation of long-term benefits that have a strong potential to increase the volume and value of the MICO resource. This paper will discuss the various mine geology contributions at MICO and illustrate some examples where mine geological input from graduate level has added significant value to the MICO business.

Jan 1, 2007

By G. L. Smith

[Research and development conducted by CSR.-Mining Technology in the areas of active continuous miner based coal dust/methane explosion suppression systems, passive 'bag based, atone dust barriers systems, din and positioning of refuge bays, integrated escape and rescue strategies, and neural network based coal dust/methane explosion risk assessment is briefly described. It is concluded that effective catastrophic risk management of coal dust/methane explosions is dependent on an integrated, systems approach drat encompasses fundamental understanding of hazard sources, qualitative and quantitative probability of occurrence, magnitude of consequences and efficacy of control and recovery measures.]

Jan 1, 1999

By Frank C. Andreuzzi

The Federal Bureau of Mines conducted a demonstration project to reclaim 125 acres of abandoned strip-mined land in Lackawanna County, Pa., for public recreational, historical, and educational use as a park. The Bureau was involved in the development of the general site plan, and engineered and supervised the basic land rehabilitation. The park's Facilities include outdoor recreational activities, picnic grounds, children's play areas, primitive overnight camping, and winter sports. A major attraction is the Anthracite Museum constructed by the Pennsylvania Historical and Museum Commission The project may serve as a prototype for reclaiming existing and future surface-mined lands.

Jan 1, 1976

By G. Van Weert, J. F. Breedveld

Both regular and Silver Impregnated Activated Carbon (SIAC) were studied for their effectiveness in removing WAD (Weak Acid Dissociated) cyanides from solutions at pH = 10. SIAC has already been shown to be effective in the removal of free cyanide down to 30 ppb or less. The present work deals with complexed cyanides. Zinc cyanide was used to represent the WAD component. At pH=10, in either batch or column tests it was not possible to lower the total cyanide in solution from either 30 or 8 ppm to less than 1 ppm, using SIAC, regular activated carbon as received, or after grinding. Silver (metal) impregnation of the carbon was not beneficial in the removal of WAD cyanide. However, when silver is added as silver ions (nitrate), the cyanide is adsorbed as silver cyanide in preference to zinc cyanide. The latter compound converts to zinc (hydr) oxide. This way, the cyanide concentration in solution can be lowered below 1 ppm, even when zinc cyanide is already adsorbed on the carbon used. A single exploratory test with added copper ions indicated a similar effect for that system.

Jan 1, 2004

The 18th annual American Mining Hall of Fame Awards Banquet sponsored by the Mining Foundation of the Southwest will be held on Saturday, Dec. 2, 2000 at The Westin La Paloma in Tucson, AZ. The 2000 inductee, guest of honor and featured speaker at the banquet will be Ronald C. Cambre, chairman and chief executive officer of Newmont Mining. He will be honored for his role in positioning Newmont as an innovative and key player in the gold mining industry.

Jan 1, 2000

By B. N. Hira

A multistoreyed residential complex was at the penultimate stage of construction by ONGC at Nazira, Assam. The site was situated at high earthquake zone. The subsoil was very weak and contained soft to medium clay with water table almost at the ground level. The bearing capacity of soil was quite poor particularly with predicted settlement beyond permissible limit. In this situation, the conventional shallow and deep foundations were found uneconomical and ground improvement with granular piles was considered as the viable solution. ONGC approached the Central Building Research Institute with the request to design granular piles along with R.C.C. foundation and other suitable cost effective measures. CBRI collected relevant geotechnical informations and supplimented the data by conducting field tests at site and laboratory tests at Roorkee. Rational design of 30 cm dia. and 5.00 meter deep granular piles were suggested with isolated and combined RCC footings over the reinforced soil. In addition to several structural and geotechnical advantages, the granular pile foundation provided considerable economy in the cost of construction. The paper presents the salient geotechnical and structural informations of the challenging project and provides the design details of the innovative granular pile-system. It also furnishes the design approach of the RC footings and other elements of the foundation.

Jan 1, 1996

By R. H. Fernald

In investigating general problems that relate to the fuel resources of this country, and in testing fuels belonging to or for the use of the Government, the Bureau of Mines has given considerable attention to the efficiency and economic value of producer-gas power plants. Government inquiries during the past eight years not only have shown a very low fuel consumption per horsepower-hour for these plants but have demonstrated conclusively the possibility of utilizing commer- cially low grades of bituminous coal, lignite, and peat in plants prop- erly designed for the use of these fuels. The anthracite plant has been recognized as a commercial possibility for several years, although the cost of the fuel used has in general restricted these plants to com- paratively small units. The commercial development of the producer-gas power plant in the United States has been largely within the past six or eight years. In 1909 the United States Geological Survey published in a bulletin entitled "Recent Development of the Producer-Gas Power Plant in the United States" a list of producer-gas power-plant installations. The data presented in that bulletin showed a strong development in this field and led to much conjecture as to the future of this type of power. Owing to the extensive introduction of the steam turbine, however, many persons predicted the almost immediate doom of the producer-gas plant. In addition to the inroads made by this formida- ble rival, the interest of the gas-engine enthusiasts became centered to such an extent in the oil engine that the gas producer was relegated to second place by many and absolutely abandoned by some. During the past three years the belief of many who were formerly firm be- lievers in the gas producer has been that this type of power has reached its height of development in this country and that from a commercial standpoint it can no longer be regarded as a complete success. This feeling of commercial decadence has become so general

Jan 1, 1913

By Lyall Zickrick

NUMEROUS brands of virgin pig lead are used in the manufacture of lead and lead-alloy cable sheath for commercial cables. In changing from one brand of pig lead to another a readjustment of press operating conditions is nearly always necessary. This is due largely to different flow characteristics, and some brands extrude at a much lower pressure than others; for example, copper-bearing lead requires much more pressure than a low-bismuth lead under the same operating conditions. With the modern type of lead press the extrusion practice in general differs very little. Molten lead at a temperature of 375° to 400° C. (710° to 750° F.) is cast in a water-cooled cylinder and allowed to cool or solidify into a slug for six to nine minutes. . This slug is forced into the die block and around the core tube through which the cable runs. The die block is held at an optimum temperature by means of gas flames, usually 175° to 225° C. (350° to 4.35° F.). Measurements of the tem¬perature of the cable sheath taken at the time of extrusion have covered a range of 190° to 225° C. (375° to 435° F.). According to Tammann, the rate of extrusion for a metal under constant pressure through a simple orifice is almost doubled for each 10° C. rise in temperature. Because of the irregularity of die-block construction, such a great increase is not obtained in lead-cable extrusion practice. To obtain more" definite information about the effect of small per¬centages of metals usually present as impurities in virgin pig lead, a series of compression tests were made covering several different brands of lead and various alloys. Since the usual temperature of the sheath is approxi¬mately 200.° C. as it emerges from the die block, these compression tests were all performed at 200° C. Five different brands of virgin pig lead were selected, as follows: Brand A: A desilverized western lead of very high purity. This lead contains neither copper nor bismuth. Brand B: A bismuth-free southeastern Missouri lead, usually con¬taining 0.05 to 0.08 per cent copper. Brand C: A copper-free mid-western desilverized lead of very good grade, usually containing around 0.06 to 0.10 per cent bismuth.

Jan 1, 1932

By R. H. Sprute

Extensive Bureau of Mines laboratory testing has shown that electrokinetic densification can be an effective method for dewatering and consolidating unclassified metal mine mill tailings. The report describes results of a limited field test of this technique. Eighteen-cubic-yard concrete model stopes, 18 feet long by 6 feet deep by 56 inches wide, were filled with unclassified tailings slurry from a metal mine in the Coeur d'Alene, Idaho, district. Five different tests were performed. They showed that a strong, dense, dewatered fill can be obtained in a reasonably short time using electrokinetics, with typical power consumption of 25 to 30 kW-hr/yd3 of densified fill. At present power costs in the Coeur d 'Alene district, this would amount to 10 to 12 cents/yd3.

Jan 1, 1975

By Gabriela Fernández-Dávila

Los diecisiete Objetivos de Desarrollo Sostenible de las Naciones Unidas (ODS) constituyen parte importante de la agenda global orientada a erradicar la pobreza, proteger el planeta y asegurar la prosperidad para todos. En un contexto de constante expectativa social y, ya que el sector minero es tan relevante en nuestro país, por ser el que aporta la mayor cantidad de riqueza económica, cabe asumir el reto de incluir en la agenda del sector un enfoque de inversión que incluya a los ODS como marco orientador de las iniciativas que buscan contribuir a mejorar la calidad de vida de la población.

Sep 20, 2019

By Marino Gaspar

El presente texto tiene como objetivo la mejora de gestión de mantenimiento de la flota, el aumento de la productividad y eficiencia de los scoop en el proceso de monitoreo de la mina Los Quenuales de la unidad minera Yauliyacu. Para ello, se desarrolla SIMORES, un sistema que recolecta toda la información accesible de los scoop, para que se tenga una perfecta gestión de la flota de scoop con la máxima productividad y eficiencia. Dicha información genera datos como: tiempo de uso del motor, consumo del combustible, uso de los cambios de la transmisión, información de servicio, etc que permite monitorear y administrar mejor el equipo, haciéndolo más productivo.

Sep 24, 2008

By W. O. Crosby

The crystalline belt of the Atlantic Seaboard, south of New York, attains its maximum breadth of 220 miles on the northern border of North Carolina; arid in this State it is most widely characterized by the occurrence of gold in workable deposits. Half a dozen auriferous belts have been recognized by Nitze and Hanna.' These are, in the main, coincident in position and trend with the NE.—SW. zones of metamorphic slates and schists, which, more than any other feature, give character to the geological map of North Carolina. The central gold-belts, accompanying the main zone of slates and as-

Jan 1, 1908

By Ernest J. Conway

This report presents engineering drawings for six material handling devices for underground coal mines. The devices were designed under a U.S. Bureau of Mines program to reduce injuries from material handling during mine and equipment maintenance. The six devices are (1) scoop-mounted 1411: boom, (2) swing-arm boom, (3) heavy-component lift-transport, (4) mine mud cart, (5) container-workstation vehicle, and (6) timber car. Each device is described briefly, and recommendations are made concerning the design of new devices.

Jan 1, 1989

By Lowell B. Page

The White River Shale Project has completed a 5,000-foot production decline and a 30-foot diameter 1,010-foot deep shaft into its oil shale orebody in the Uinta Basin of eastern Utah. This is the first major underground access into these Green River deposits in this basin and provides an opportunity to establish and monitor in-situ rock mechanics stations as input to the mine engineering and planning of this large opening, high-tonnage mine. This paper discusses the history, mine development, and rock mechanics planning for this project.

Jan 1, 1984

By Yong Zhao, Yan-hui Sun

Behaviors and evolutions of MgO·Al2O3 in non-oriented silicon steel during calcium treatment were investigated by thermodynamic calculations and high-temperature experiments. MgO·Al2O3 inclusions were the main type of inclusions before calcium treatment, which is also confirmed by the stability diagram of MgO/MgO·Al2O3/Al2O3 from thermodynamic calculations. After calcium treatment, the majority of original MgO·Al2O3 inclusions were mainly modified to CaO-MgO-Al2O3 system inclusions, this would be beneficial to improve castability and product quality of silicon steel. But there was no modification happening to some MgO·Al2O3 spinels which were directly surrounded by CaS inclusions. The content of Al2O3 occasionally existed a sudden increase besides a common decrease in the product layer of CaO·MgO·Al2O3. Then the evolution mechanisms of MgO·Al2O3 inclusions were proposed in present work. Thus, Al/Mg atom ratio had a significant influence on the modification of MgO·Al2O3 spinel.

Jan 1, 2016