Entity

Time filter

Source Type


Predeanu G.,Metallurgical Research Institute | Panaitescu C.,Polytechnic University of Bucharest
Revue Roumaine de Chimie | Year: 2010

The aim of this study is to review the application of the petrographic research, as a no-destructive method, in a number of carbon some adsorbents and non-conventional carbon materials developed in Romania, as are: intercalated composites, nano-composites and vitreous carbon. In addition to previous studies, corresponding set of samples were examined, with special emphasis on developing of the texture during carbonization and activation. The activated carbon microstructure reveals some interesting aspects concerning the thermal processes as evolution, efficiency and pore development. In the activated carbon the adsorption surface development through a highly porous system, depends on the type of petrographical components, raw material grain size and pyrogenationactivation parameters. In the non-conventional carbon materials manufacturing, the physical-chemical characteristics depend on the type of petrographic composition of the raw materials and processing conditions, with influence on the products performances. The paper reveals that microscopically evaluation could be useful even in some domains in which only the classical physical methods seem to be efficient. Source


Chipurici P.,Polytechnic University of Bucharest | Calinescu I.,Polytechnic University of Bucharest | Gavrila A.I.,Polytechnic University of Bucharest | Predeanu G.,Metallurgical Research Institute
UPB Scientific Bulletin, Series B: Chemistry and Materials Science | Year: 2010

This paper presents the studies realized for removal of different pollutants (benzene, toluene, xylene, phenol) in the purification process of water by adsorption on various multipurpose carbon materials. The adsorptive properties of multipurpose carbon materials obtained from different vegetal sources were studied by comparison with a commercial active charcoal. The necessary time for reaching the adsorption equilibrium in static conditions as well as the removal efficiencies of the pollutants were determined. All studied multipurpose carbon materials have been shown good removal efficiencies of the corresponding pollutants. Source


Panaitescu C.,Polytechnic University of Bucharest | Predeanu G.,Metallurgical Research Institute
Revue Roumaine de Chimie | Year: 2010

The major objectives of this review paper are: to emphasize the aspects concerning Roumanian contribution during the last few decades on different manufacturing processes of carbon materials & products and to reveal the application of petrographic researches in case of carbon materials. Some representative carbon materials were sampled as: raw materials, intermediary and end products, with a special reference to the optical properties determined by their structural composition and texture. In the carbon materials manufacturing, the physical-chemical characteristics that depend on the type of optical properties (petrographic composition) of the raw materials and processing parameters, prove a great impact on the products performances. Source


Radu A.-L.,Romanian National Institute for Research and Development in Chemistry and Petrochemistry | Sarbu A.,Romanian National Institute for Research and Development in Chemistry and Petrochemistry | Motoc S.,Metallurgical Research Institute | Mara L.,National Research Development Institute For Nonferrous and Rare Metals IMNR | And 6 more authors.
Materiale Plastice | Year: 2010

Mesoporous silica was obtained by the acid attack of a serpentinite rock. This material was soaked with acrylonitrile (containing azobisisobutyronitrile as initiator) and the radical polymerization led to the obtaining of polymer inorganic-organic nanocomposites. The polymer nanocomposites were transformed in carbonsilica nanocomposites by the cyclization and graphitization of the carbon chain polymer. Heating the carbonsilica nanocomposite in nitrogen atmosphere allowed the synthesis of silicon nitride, a raw material for special ceramics. Source


Predeanu G.,Metallurgical Research Institute | Volceanov E.,Metallurgical Research Institute | Abagiu A.T.,Metallurgical Research Institute | Cruceru M.,Constantin Brancusi University | Slavescu V.,Metallurgical Research Institute
International Multidisciplinary Scientific GeoConference Surveying Geology and Mining Ecology Management, SGEM | Year: 2013

This paper aims to investigate the characteristics of the ash stored in external dumps of a Romanian energy power plant in order to identify some ways to reuse it as ceramic material. Laboratory tests have been carried out on the supplied ash samples in order to establish the physical characteristics (moisture, bulk density and grain size composition) and chemical composition, by X-Ray fluorescence (XRF), X-ray diffraction, high temperature microscopy analysis. Chemical properties of ash samples reveal valuable oxides such as SiO2, Al2O3, CaO, Fe2O3, and other oxides, which vary as composition, density, texture, porosity and water absorption capacity, which are adequate in comparison with those of the ceramic raw materials usually used in the ceramic industry. In terms of basic physical characteristics, the ash can be assimilated to a natural sand aggregate of granular type, except for bulk density characterized by lower values. Also, preliminary measurements of radioactivity made by a gamma ray detector shows the existence of 226Rd and 232Th radionuclide, the irradiation on radiation protection being at a level, close but lower than of the health admitted norms. The present study helps to find out that chemical properties of ash samples reveal adequate characteristics in comparison with those of the raw materials usually used in the ceramic industry. The results show that vitrified ceramics can be developed from coal ash and provide the best conditions to obtain products with desirable properties suitable for construction sector. © SGEM2013 All Rights Reserved by the International Multidisciplinary Scientific GeoConference SGEM. Source

Discover hidden collaborations