Composition and pozzolanic properties of pulverised fuel ashes. I. Composition of fly ashes from some British power stations and properties of their component particles

2007 ◽  
Vol 15 (12) ◽  
pp. 585-594 ◽  
Author(s):  
J. D. Watt ◽  
D. J. Thorne
Keyword(s):  
Fly Ashes ◽  
Power Stations ◽  
Pozzolanic Properties

scholarly journals Properties of Fly Ashes from Thermal Power Stations in Relation to Use as Soil Amendments

2019 ◽  
Vol 48 (4) ◽  
pp. 745-755
Author(s):  
Le Van Thien ◽  
Ngo Thi Tuong Chau ◽  
Le Thi Tham Hong ◽  
Nguyen Thu Trang ◽  
Hiroyuki Futamata
Keyword(s):  
Soil Amendments ◽  
Thermal Power ◽  
Fly Ashes ◽  
Power Stations ◽  
Thermal Power Stations

scholarly journals Insights into PCDD/Fs and PAHs in Biomass Boilers Envisaging Risks of Ash Use as Fertilizers

2020 ◽  
Vol 10 (14) ◽  
pp. 4951
Author(s):  
Helena Lopes ◽  
Susana Proença
Keyword(s):  
Unburned Carbon ◽  
Fly Ashes ◽  
Power Stations ◽  
Polycyclic Aromatic ◽  
Toxic Equivalents ◽  
One Year ◽  
Definition Of ◽  
And Control ◽  
The Impact ◽  
Biomass Ashes

Since ashes are a possible source of Persistent Organic Pollutants (POPs) contamination, their application in soils must be subject to more study and control. In this scope, feed residual forest biomasses and biomass ashes, collected along one year in four biomass power stations, were characterized mainly for their polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) and Polycyclic Aromatic Hydrocarbons (PAHs) contents. The biomasses present concerning levels of Cl (0.04–0.28%) that may lead to PCDD/Fs formation. The biomasses also contain OCDD (29–260 ng/kg) and 1,2,3,4,6,7,8-HpCDD (35 ng/kg) that may contribute to increased Toxic Equivalents (TEQs) of ashes, possibly involving dechlorination and ash enrichment mechanisms. While the WHO2005-TEQs in bottom ashes (14–20 ng TEQ/kg) reaches the proposed limit (20 ng TEQ/kg) for ash use as fertilizers, in fly ashes (35–1139 ng TEQ/kg) the limit is exceeded. PAHs are below 0.02 mg/kg in bottom ashes and 1.5–2.5 mg/kg in fly ashes, complying with the proposed limit of 6 mg/kg. As bottom and fly ash streams may contain different ash flows, a clear definition of ash mixes is required. Correlations between unburned carbon (C), PAHs and PCDD/Fs were not found, which highlights the need for compulsory PCDD/Fs analysis in ashes, independently of their origin, burnout degree or levels of other contaminants. A sensitivity analysis was performed to evaluate the impact of handling non-detected values, which showed more impact for TEQs values close to the proposed regulatory limit of PCDD/Fs. These findings highlight the need to define reporting protocols of analytical results for risk assessments and conformity evaluation.

Image Analysis of Fly Ash in the Characterization of the Shape of the Grains

1994 ◽  
Vol 370 ◽  
Author(s):  
M. Barrioulet ◽  
H. Cros ◽  
B. Husson ◽  
E. Ringot
Keyword(s):  
Image Analysis ◽  
Fly Ash ◽  
Mineralogical Composition ◽  
Fly Ashes ◽  
Particle Content ◽  
Power Stations ◽  
Fresh Material ◽  
Quantitative Image ◽  
Strength And Durability

AbstractFly ash from power stations is used as concrete additive to improve strength and durability. Surprisingly, studies of ashes of identical mineralogical composition from two different places have reported different results in terms of the rheological properties of the fresh material. The viscosity of the pastes made from these different fly ashes seems to be linked to the proportion of spherical and smooth-shaped grains found in them. A quantitative image analysis was carried out to characterize the shape of the grains of these two ashes from different geographical origins. The main result proves that the higher the glassy particle content of the fly ash, the more the hydraulic matrix is fluid.

Relationship Between Pozzolanic Activity and Chemical and Physical Characteristics of Selected Canadian Fly Ashes

1985 ◽  
Vol 65 ◽  
Author(s):  
R. C. Joshi ◽  
V. M. Malhotra
Keyword(s):  
Fly Ash ◽  
National Standard ◽  
Fly Ashes ◽  
Bureau Of Reclamation ◽  
Supplementary Cementing Materials ◽  
University Of Calgary ◽  
Fly Ash Utilization ◽  
The University ◽  
Pozzolanic Properties ◽  
The U.S

Raymond E. Davis and his associates appear to have coined the term “fly ash” in 1937. Following the pioneering studies by the U.S. Bureau of Reclamation for the Hungry Horse Dam, the use of fly ash for massive hydroelectric structures increased rapidly in the U.S., with ASTM issuing the first standard in 1954. In 1982, Canada issued a National Standard, CAN 3-A23.5-M82, entitled “Supplementary Cementing Materials and Their Use in Concrete Construction.” Because of the increasing interest in fly ash utilization, Canada Centre for Mineral and Energy Technology (CANMET) initiated research in the area of supplementary cementing materials in the early 1970's and has since published several comprehensive reports on the subject [1,2]. At the University of Calgary, we are studying Canadian fly ashes and their use in concrete, through an investigation of the physical, chemical, mineralogical and pozzolanic properties of fly ashes from fourteen sources across the country. We report here preliminary results from this study.

Characterization of Canadian fly ashes and their relative performance in concrete

1987 ◽  
Vol 14 (5) ◽  
pp. 667-682 ◽  
Author(s):  
G. G. Carette ◽  
V. M. Malhotra
Keyword(s):  
Fly Ash ◽  
Setting Time ◽  
Air Entrainment ◽  
Relative Performance ◽  
Hardened Concrete ◽  
Freezing And Thawing ◽  
Fly Ashes ◽  
Wide Range ◽  
Pozzolanic Properties

Eleven Canadian fly ashes were characterized and evaluated for their relative performance in concrete. Characterization included the determination of mineralogical composition, chemical composition, physical characteristics, and pozzolanic properties. The relative performance of each fly ash in concrete was evaluated through determination of the following properties of fresh and hardened concrete: slump, air content, bleeding, setting time, strength, modulus of elasticity, drying shrinkage, creep, and freezing-and-thawing resistance.The results indicate a wide range of chemical, physical, and pozzolanic properties for the fly ashes investigated. In spite of this, all the fly ashes studied are shown to be suitable for use in concrete. They affect, however, the properties of fresh and hardened concrete in different ways, and this should be taken into account when proportioning concrete containing these fly ashes. Key words: fly ash, concrete, pozzolanic activity index, bleeding, setting time, air-entrainment, strength, creep, shrinkage, freezing and thawing.

Quantitative Phase Analysis of Fly Ashes from Six Polish Power Stations

2007 ◽  
Vol 130 ◽  
pp. 277-280
Author(s):  
Hanna J. Krztoń
Keyword(s):  
Rietveld Refinement ◽  
Phase Analysis ◽  
Rietveld Method ◽  
Quantitative Phase Analysis ◽  
Fly Ashes ◽  
Quantitative Phase ◽  
Power Stations

Application of the Rietveld method to quantitative phase analysis of fly ashes from Polish power stations is presented. The calculations of the fractions of crystalline components as well as non crystalline constituents have been done using SIROQUANT TM software. The power of the Rietveld refinement is shown when very small contents of minerals are detected and quantified.

Methods for Characterization of Composition of Fly Ashes from Coal-Fired Power Stations:  A Critical Overview

2005 ◽  
Vol 19 (3) ◽  
pp. 1084-1098 ◽  
Author(s):  
Stanislav V. Vassilev ◽  
Christina G. Vassileva
Keyword(s):  
Fly Ashes ◽  
Power Stations ◽  
Critical Overview
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