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Geological Engineering

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Articles 91 - 94 of 94

Full-Text Articles in Bioresource and Agricultural Engineering

Waste Stabilization/Solidification (S/S) Of Eaf Dust Using Fly Ash-Based Geopolymers. Influence Of Carbonation On The Stabilized Solids, Y. Luna Galiano, C. Fernandez Pereira, J. Vale Jan 2010

Waste Stabilization/Solidification (S/S) Of Eaf Dust Using Fly Ash-Based Geopolymers. Influence Of Carbonation On The Stabilized Solids, Y. Luna Galiano, C. Fernandez Pereira, J. Vale

Coal Combustion and Gasification Products Journal Archive

The effect of the curing in a carbonated ambient of the solids obtained after the stabilization/solidification (S/S) of metallurgical waste using geopolymerization technology is described in this paper. The electric arc furnace (EAF) dust to stabilize contains hazardous metals such as Pb, Cd, Cr, or Zn. Different geopolymeric agents such as potassium hydroxide, potassium silicate, metakaolin, and blast furnace slag have been used. Mixtures of EAF waste with these geopolymeric materials and class F fly ash as main silica and alumina source have been processed. Samples were submitted to an accelerated carbonation test. Compressive strength tests and different leaching tests …


Variations In Fly Ash Composition With Sampling Location: Case Study From A Portuguese Power Plant, B. Valentim, A. Guedes, D. Flores, C.R. Ward, J.C. Hower Jan 2010

Variations In Fly Ash Composition With Sampling Location: Case Study From A Portuguese Power Plant, B. Valentim, A. Guedes, D. Flores, C.R. Ward, J.C. Hower

Coal Combustion and Gasification Products Journal Archive

Fly ash (FA) is a heterogeneous and complex material resulting from coal combustion in thermoelectric power plants (TPP). Therefore, different types of coals, worldwide, produce FAs with different compositions. However, the location of the FA sampling system, inside the TPP, is also important to the composition of the FA produced at each location. A case study of FA from a Portuguese TPP, using several coal and FA characterization techniques (particle size analysis, proximate and ultimate analyses, XRF, SEM/ESEM/EDS, Optical microscopy, XRD, inferred chemistry, and AAS), has shown that FA chemical classification, mineralogy and phase-mineral classification, and trace elements (Cr, Cu, …


Zeolite Synthesised From Fused Coal Fly Ash At Low Temperature Using Seawater For Crystallization, Claudia Belviso, Francesco Cavalcante, Antonio Lettino, Saverio Fiore Jan 2010

Zeolite Synthesised From Fused Coal Fly Ash At Low Temperature Using Seawater For Crystallization, Claudia Belviso, Francesco Cavalcante, Antonio Lettino, Saverio Fiore

Coal Combustion and Gasification Products Journal Archive

A sample of coal fly ash from an Italian thermoelectric power plant was used in order to synthesize zeolite by hydrothermal activation after a pre-treatment fusion with NaOH. The experiments involved were performed at different temperatures of crystallization, ranging from 35 up to 60uC, with seawater and distilled water, separately, during hydrothermal process. A comparison between the results obtained from the use of the different kinds of water showed that at low temperature (35–40 uC) the synthesis yield of zeolite X is higher using seawater as crystallizing agent than using distilled water. This implies a possible application for seawater in …


Optical Properties Of Coal Combustion Byproducts For Particle-Size Analysis By Laser Diffraction, Robert B. Jewell, Robert F. Rathbone Jan 2009

Optical Properties Of Coal Combustion Byproducts For Particle-Size Analysis By Laser Diffraction, Robert B. Jewell, Robert F. Rathbone

Coal Combustion and Gasification Products Journal Archive

Laser diffraction analysis is commonly used for determining the particle-size distribution (PSD) of fly ash. However, there is currently no standard method for preparing samples and analyzing them. The Mie and Fraunhofer optical models are used to calculate the PSD of fly ash from laser diffraction data. The Mie theory is most applicable for particles smaller than 50 mm, and is therefore the most accurate model for the analysis of fly ash. However, the refractive index (RI) of fly ash is complex and not well known. This study presents the analysis of several supplementary cementitious materials (SCMs) such as coal …