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By Mark C. Malamphy

MAJOR JUAREZ TAVORA, who recently accepted the post of Minister of Agriculture in Brazil, has reorganized his department. Not least among those sub: divisions of the "Ministerio" which underwent radical changes in the general reform was the Serviqo Geologico e Mineralogico do Brasil. This well- known organization was declared extinct, and in its place was created a new cleparttnent ' termed "Departamento Nacional cle Producqao Mineral," which immediately took over all the work of the olcl Servico Geologico ill addition to certain new duties. Dr. .. Domingos Fleury- da Rocha, former head of the School of Mines of Ouro Preto, was called to Xio to assume the newly created post of Director General of the department of Mineral Production. His department will have live divisions :

Jan 1, 1934

By A Späth

Active explosion barriers are used to contain and suppress a methane gas and/or coal dust explosion propagation, including localised mine fires. Early research indicated that these active explosion barriers could be used on a mechanised cutting machine, making it the only technology that could suppress an explosion during its propagation phase at the cutting face. Thereby not only adding protection during mining operations but also reducing the development of toxic gases, fatal temperature increase and fatal overpressure build-up. During their evolution over the last two decades, further advantages of Active explosion barriers were proven in mine operations in countries such as South Africa and China. Characteristics such as effectivity, efficiency, mobility and space restrictions allow these systems to be used in various locations within a mine operation, including highwall operations. This improved technology contribution to safer coal mining was recognised by mine operators, workers and regulators. The Queensland’s Recognised Standard 21 (Resources Safety and Health Queensland (RSHQ), 2021) stipulated active explosion barriers as a technology to ensure the safety within their underground coalmines. The mobility and flexible implementation of the active explosion barriers allow a feasible and practical solution for all critical locations for explosion and fire management in an underground coalmine. The conformance to the Recognised Standard can be achieved all underground coal mining operations such as Bord and Pillar, and Longwall mining. This paper describes the conformance, implementation and use of Active explosion barriers for Longwall mining and development as well as Bord and Pillar mining in Queensland’s underground coalmines.

Oct 12, 2022

Addicks, L Ambler, J O Anderson, F B Armstrong, T Allen, L M, Jr Arnold, C E Adams, C E Adams, R E Anderson, A J Booth, E L Bernhardt, D I Boyd, W S Browning, W C Blake, D E Black, T B Bergman, Julius Bowen, H P Beckett, P G Blickensdefer, F C Bond, Josiah Butler, P P Bondlas. Y

Jan 1, 1923

By G E. Holt

Active EM subsurface imaging is a proprietary technique developed by Marschall Acoustics Instruments Pty Limited (MAI) to image subsurface features at depths useful for the mining industry. Similar in field operations to high resolution seismic surveying, the Active EM technique employs electromagnetic energy rather than elastic wave energy. Received backscattered energy in the Active EM technique is thus due to differences and contrasts in electromagnetic permeability and permittivity in the subsurface, analogous to LamTÆs constants in elastic wave imaging. Carrying the analogy to seismic imaging even further, the Active EM method employs high power transmissions of very wide-band coded signals of a controlled polarisation. Likewise, the array pattern and polarisation of the receiving transducers is also tightly controlled. Thus, in a certain mathematical sense, Active EM is the electromagnetic equivalent of high power high resolution vibroseis seismic surveying. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By Linfeng Zhou, Rong Sun, Guanghui Li, Zhiwei Peng, Tao Jiang

Dust, or airborne particulate matter, from metal smelting can be either mechanically or thermally generated and it negatively affects the indoor air quality as well as the fugitive emissions from the plant. The thermally generated dust is often referred to as fume and it is typically generated whenever liquid metal comes into contact with air. For practical reasons, such as vehicle access, etc. it is often difficult to collect 100% of the fume. It is therefore highly desirable to develop processes and optimize operational procedures so that fuming can be kept to a minimum. In this series of experiments, the mechanism of active oxidation and fume formation from liquid silicomanganese under an impinging air jet in the temperature range 1400-1600°C has been explored. Characteristic properties of the fume have been established; particle diameter, shape, size distribution, and elemental composition are reported. The oxidation process is described in terms of vaporization, oxidation and agglomeration. In the boundary layer, two competing mechanisms seem to be operative in parallel: a direct oxidation of Mn vapor, and a two-step oxidation of silicon. The thermodynamic and kinetic conditions governing the two mechanisms are discussed.

Jan 1, 2016

By W. H. Schiffbauer

The U.S. National Institute for Occupational Safety and Health (NIOSH) developed an active proximity warning system called hazardous area signaling and ranging device (HASARD) for warning workers as they approach known dangerous areas around heavy mining equipment and other dangerous work zones. HASARD is composed of a transmitter and a receiver. The transmitter generates a 60-kHz magnetic field using one or more wire loop antennas. Each antenna is adjusted to establish a magnetic field pattern for each hazardous area. The receiver, which is worn by the worker, is a magnetic field strength meter. The received signal is compared against preset levels that are calibrated to identify levels of danger. The receiver outputs can include visual, audible and vibratory indicators, and it can also be made to disable machine functions. HASARD was field tested on a Joy 12 continuous miner, a Komatsu 210 M Haulpak and on a high wall launch vehicle. Slight modifications were made for each application. HASARD provided warnings as designed, and it proved to be rugged enough to withstand the harshest of production environments.

Jan 1, 2003

By Martin B. Hudson, Andrew K. Cho, Rolff B. Knobel, Les R. Chernauskas, Jonathan L. Ernst

ABSTRACT The Bruce Museum, located in Greenwich, Connecticut, is home to an extensive display of art and natural history exhibitions. A large addition was designed to be constructed adjacent to the museum requiring new spread footings to be installed up to 16.5 feet below the existing foundations. The soil conditions at the site consist of highly variable sand and gravel overlying weathered rock and sound bedrock. The Contract Documents called for traditional foundation underpinning. Traditional underpinning techniques, however, presented two major challenges on this Project; (1) deep underpinning pits would be required involving multiple levels and staging with tieback support and (2) the highly variable soil and bedrock composition and elevations presented uncertainty in the design and construction of the pits. In lieu of traditional underpinning, Geosciences Testing and Research, Inc. (GTR) proposed an “active” soil nail underpinning system. A major reason that the soil nail underpinning option was feasible, related to the fact that the soil nails and facing could be installed slightly in front of the existing footings rather than directly underneath the existing footings. The soil nail wall design involved one to four rows of soil nails with nail positions and wall depth able to be adjusted “on the fly” as excavation progressed depending on the field conditions encountered. To create the “active system,” the soil nails were pre-loaded to mitigate wall deformations that would be associated with a standard passive soil nail wall design. To evaluate the performance of the active soil nail wall and confirm design assumptions, an extensive automated monitoring, on-site testing and inspection program was proposed and executed by GTR to monitor deformations of the wall and the museum in real-time, evaluate and confirm bedrock and soil bond stresses and ensure that each soil nail was pre-loaded and locked off. Careful analysis, planning, and use of the observational method illustrates the importance of collaboration between design and construction personnel and applying engineering judgement throughout construction. The use of the observational method includes the potential for modifying design based on conditions observed. This paper presents a unique case study of the “active” soil nail underpinning system to support and protect sensitive structures, close collaboration between design and construction facilitated by real-time deformation monitoring, and its successful application as a safe and cost-effective alternative to traditional underpinning.

Oct 1, 2022

By Camilo Ferreira, Franco Olcese

Hay intensos debates respecto a los impactos de la minería en sobre el desarrollo de las comunidades en su entorno. Inclusive existen corrientes ideológicas que consideran que la minería empobrece y amenaza la salud de las comunidades en su entorno. En esta investigación evaluamos la medida en la cual exista evidencia que sustente estas posturas. Estimamos el impacto de la minería a nivel de los distritos del Perú, tanto mediante el canon como por el valor de la producción minera, sobre el índice de desarrollo humano, ingreso familiar per cápita y esperanza de vida.

Sep 30, 2022

By Georg Petersen

El presente artículo describe la actividad petrolera realizada durante el año 1962. En 1863 el Gobierno del Perú derogó al Ing. A. E. Prentice el estudio de las posibilidades petroleras de Piura y Tumbes, a través de la perforación del primer pozo de petróleo en Zorritos a través de herramientas imperfectas. Ante tal éxito, en 1864 Lama y Rudens gestionaron que se constituya en Nueva York la "Compañía Peruana de Petróleo". Posteriormente, doce compañías petroleras han desarrolado trabajos de exploración y nueve se encuentran en estado de producción. En este plano tenemos a Belcom Petroleum Corporation Perú, Cerro de Pasco Company, Empresa Petrolera Fiscal, Compañía peruana de Petróleo "El Oriente", International Petroleum Company, Mobil Oil Company, Mobil Oil Company of Perú, Compañía de petróleo Ganso Azul, Peruvian, entre otros.

Jul 1, 1963

By Georg Petersen

El presente artículo describe la actividad petrolera realizada durante el año 1962. En 1863 el Gobierno del Perú derogó al Ing. A. E. Prentice el estudio de las posibilidades petroleras de Piura y Tumbes, a través de la perforación del primer pozo de petróleo en Zorritos a través de herramientas imperfectas. Ante tal éxito, en 1864 Lama y Rudens gestionaron que se constituya en Nueva York la "Compañía Peruana de Petróleo". Posteriormente, doce compañías petroleras han desarrolado trabajos de exploración y nueve se encuentran en estado de producción. En este plano tenemos a Belcom Petroleum Corporation Perú, Cerro de Pasco Company, Empresa Petrolera Fiscal, Compañía peruana de Petróleo "El Oriente", International Petroleum Company, Mobil Oil Company, Mobil Oil Company of Perú, Compañía de petróleo Ganso Azul, Peruvian, entre otros.

Jul 1, 1963

By Luis Palomino

El siguiente estudio indica la importancia de la función que ejerce el Departamento de entrenamiento en la Cerro de Pasco Corporation. Para ello, la compañía reconoce el entrenamiento como herramienta básica en el aumento de la producción y reducción de costo, al tiempo que el Departamento asegura el perfeccionamiento de su personal de toda índole. En esta primera etapa de planeamiento, se proponen las siguientes actividades: orientación de nuevos servidores, entrenamiento de supervisores, curso de pre-capataces, curso de instructores, cursos técnicos, cursos vacacionales para universitarios, cursos por correspondencia y clases de castellano. Concluyendo que dicho programa, aumenta el rendimiento de los trabajadores, les crea conciencia y a su vez desarrolla actitudes proactivas, así como se destaca el adiestramiento de los supervisores sobre la técnica de enseñar a sus obreros, y por último, busca que cada compañía elabore su propio programa de acuerdo a sus necesidades de su entrenamiento y según las características de su personal.

Jul 20, 1955

By Shigeatsu Nakazawa

Activities of Bi and In in the Bi-In liquid alloy were measured over the whole range of eomposition at the temperatures from 850K to 1050K. An alloy was vaeuum-sealed in a quartz cell and heated at the temperature of interest. The absorption for 307nm radiation from Bi lamp was measured for Bi atom vapor in the cell. By heating a pure metal as a standard and measuring the absorbance as a function of the temperature, an analytical curve for Bi atom vapor was constructed and used for conversion of the absorbance to the vapor density. Bi activity was determined as the ratio of the Bi atom vapor density over the alloy to that over a pure metal. The same procedure was applied to the In 304nm radiation from In lamp and In activity was determined independently of Bi. Results showed that the liquid Bi-In system behaves like a regular solution.

Jan 1, 2003

By Shigeatsu Nakazawa

Activities of Bi and In in the Bi-In liquid alloy were measured over the whole range of composition at the temperatures from 850K to 1050K. An alloy was vacuum-sealed in a quartz cell and heated at the temperature of interest. The absorption for 307nm radiation from Bi lamp was measured for Bi atom vapor in the cell. By heating a pure metal as a standard and measuring the absorbance as a function of the temperature, an analytical curve for Bi atom vapor was constructed and used for conversion of the absorbance to the vapor density. Bi activity was determined as the ratio of the Bi atom vapor density over the alloy to that over a pure metal. The same procedure was applied to the In 304nm radiation from In lamp and In activity was determined independently of Bi. Results showed that the liquid Bi-In system behaves like a regular solution.

Jan 1, 2003

By K Saito, M Hasegawa

In steelmaking processes, it is known that P2O5 in dephosphorisation slags often exists in solid solutions between Ca2SiO4 and Ca3P2O8, <C2S-C3P>SS, and thus the solid solutions play an important role in the dephosphorisation reaction. Hence, the knowledge of thermochemical properties, ie phase relations and activities of components, in slags containing <C2S-C3P>SS are necessary for the effective removal of phosphorus from hot metal. In this study, the P2O5 activities in <C2S-C3P>SS were measured through the gas equilibrium method. In the present experiment, oxide samples were equilibrated with Cu-P liquid alloys at 1573 K under a stream of Ar + H2 + H2O or Ar + H2 + CO2 gas mixture in which oxygen potential was fixed and then equilibrium phosphorus concentrations in the Cu-P alloys, [mass%P]Cu, were analysed with ICP-OES.

Aug 21, 2024

By S. Sun

The equilibrium distribution of Cu, Fe and Ni between Cu-Ni-Fe mattes and Pt alloy was measured as functions of the sulphur partial pressure (pS2), oxygen partial pressure (pO2),temperature and Fe content of the matte. The distribution ratios of Cu, Fe and Ni between matte and alloy were independent of oxygen pressure when the pS2was fixed at 2.5x10-5atm and pO2was varied between 10-15and 10-12atm. The distribution ratio of Cu, Fe and Ni increased as the sulphur partial pressure increased. The Cu and Ni distribution ratios decreased with increasing temperature and the Fe distribution ratio increased slightly over the temperature range of1350?1500°C. For mattes where the proportions of Cu and Ni were kept constant, the distribution ratio of Cu increased as the Fe content in the matte increased. The Fe and Ni distribution appeared to be independent of the iron content in the matte and had a value of 1.2 and 1.6 respectively. The activity of Cu, Fe, Ni in the matte was calculated using a regular solution model for solid Pt-Fe-Ni-Cu alloy. The activity coefficient of Cu, Fe and Ni decreased as pO2and pS2increased.The activity coefficients also appeared to be independent of the Fe content and temperature over the range of 36 to 54 wt% iron and 1350 to 1500°C respectively. Keywords: activity, alloy, matte, thermodynamics

Jan 1, 2004

By Grigore Matei

The thermodynamic properties of CU2S-FeS system are important not only in the case of copper smelting but also in the case of general pyro-mctallurgy, However there are not many reported activity data In this study, activities of FeS and CU2S in the CU2S-FeS system were calculated using the Darken&apos;s method from the activity data of the CU2S-FeS-Sb2SJ systems measured by the transportation method at 10S0°C. The activities of CU2S and FeS in the CU2S-FeS system showed negative deviation from the ideal behaviour and satisfied the relation of the Gibbs-Duhem equation,

Jan 1, 2003

By Grigore Matei

The thermodynamic properties of CuzS-FeS system are important not only in the ease of copper smelting but also in the case of general pyro-metallurgy. However there arc not many reported activity data In this study, activities of FeS and CU2S in the Cu2S-FeS system were calculated using the Darken&apos;s method from the activity data of the Cu2S-FeS-Sb2S3 systems measured by the transportation method at 1050°C. The activities of Cu2S and FeS in the Cu2S-FeS system showed negative deviation from the ideal behaviour and satisfied the relation of the Gibbs-Duhem equation.

Jan 1, 2003

By Katsunori Yamaguchi

The zinc, lead and alumina contents in copper smelting slag are increasing with the increase in waste recycling. The recovery of base metals such as lead and zinc from copper converter slag is important from both an economical and environmental perspective. As a fundamental study of the metal recovery by reduction process, activity coefficients of ZnO and PbO in the CaO-SiO2-FeOx-5mass%AlO1.5 slag under iron saturation at 1573K are derived from the data of slag-metal equilibrium experiments. On the basis of the obtained data, the activity coefficients of ZnO and PbO in the CaO-SiO2-FeOx-5mass%AlO1.5 slag were compared with those of the CaO-SiO2-FeOx ternary system. Addition of alumina increases activities coefficient of ZnO and PbO in SiO2 rich side of the slag, and decreases them in CaO rich side.

Jan 1, 2006

By Kuwasaki N, Mitsune Y

Many activity measurements of components in liquid oxides have been reported in the field of slag chemistry. However, very little is known about the thermodynamic behavior of compo- nents in oxide solid solutions. In the present paper, e.m.fs. of the follow- ing galvanic cells employing solid electrolyte Zr02(CaO) were measured on the entire range of composition of the solid solutions. Pt/Ni-(Mgl-x ix)O/ZrO2(CaO)/Ni-NiO/Pt Pt/Ni-(Mgl-xNix)2SiO./ZrO2(CaO)/Ni-NiO/Pt Pt/Ni-(Mg l-xNix)Si03/ZrO2(CaO)/Ni-NiO/Pt. Activities of NiO in these solid solutions of (Mgl_ Nix)O and (Mgl_ Nix) 2Si0a(where 0

Jan 1, 1980

By S. N. Sinha

The distribution coefficients of lead and silver between copper and matte phases have been measured at two different temperatures. Experiments covered the ranges of 0.009-1.8, 0.07-0.13, and 0-11 wt pct lead, silver, and iron in matte, respectively. The distribution coefficients of lead have been measured at 1405 and 1505 K and correlated with lead and iron concentrations in metallic copper and matte. The values of the distribution coef¬ficient of lead between copper and iron-free matte, at infinite dilution of lead, have been determined to be 3.60 and 4,06 at 1505 and 1405 K, respectively. The distribution coefficient of silver between copper and iron-free matte is independent of silver concentrations and has been measured to be 2.13 and 2.21 at 1400 and 1500 K, respectively. For an iron-bearing matte, the distribution coefficient of silver has been correlated with iron concentration in the matte at both 1400 and 1500 K. From the measured values of distribution coefficients, the Raoultian activity coefficients of PbS and AgS0.5 in copper-saturated matte have been calculated. At infinite dilution, the following equations correlating the Raoultian activity coeffici¬ents of PbS and AgS0.5 with matte- composition and temperature have been obtained: log Y° PbS =1.515 + 1080/T 0.14 NFes lbS Fog YAgS = -0.074 - 425/T + 0.09 NFes. - 0.5

Jan 1, 1983