— The chemical states of heavy metals and radioactive Cs were estimated in fly ash sampled at Fukushima prefecture, Japan. Estimating the speciation of incinerator fly ash is important to ensure an appropriate and efficient management of fly ash generated from disaster-related waste. In this study, fl …

 — This study uses fly ash (FA) as a cement replacement in concrete and evaluates the radiological safety of this concrete sample. Different fly ash mixing ratios were investigated and found that with a mixing ratio of 35%, the compressive strength of FA concrete is the highest (from 38 to 48 MPa). Next, we evaluate the radiation safety of the …

 — According to previous durability studies carried out on specific fly ash belite cement in simulated radioactive liquid waste, which was very rich in sodium sulphate (0.5 M) [8], expansive effects were not evidenced; on the contrary, an enhancement of mechanical behaviour was produced by the ingress of sulphate and sodium ions into the ...

 — This study presents a long-term degradation behavior of fly ash blended concrete in a vault type low- and intermediate-level radioactive waste (LILW) repository by thermodynamic equilibrium calculations using PHREEQC …

 — The durability of class C fly ash belite cement (FABC-2-W) in simulated radioactive liquid waste (SRLW) rich in a mixed sodium chloride and sulphate solution is presented here. The effect of the temperature and potential synergic effect of chloride and sulfate ions are discussed. This study has been …

 — Methods of sampling fly ash: 2021: Japan: JIS A 6201: Fly ash for use in concrete: 2015: United Kingdom: BS EN 450-1: Fly ash for concrete. Definition, specifications and conformity criteria: 2012: BS EN 450-2: Fly ash for concrete. Conformity evaluation: 2005: PD CEN/TR 15840: Evaluation of conformity of fly ash for concrete. …

At one extreme, the scientists estimated fly ash radiation in individuals' bones at around 18 millirems (thouhs of a rem, a unit for measuring doses of ionizing radiation) a year. Doses for the two nuclear plants, by contrast, ranged from between three and six millirems for the same period. And when all food was grown in the area ...

 — Coal based thermal power plants contribute about ~ 72% of the power generation in India. Indian coal is of bituminous type, having a high ash content with 55-60% ash. Due to considerable environmental importance the collected fly ash has become a subject of worldwide interest in recent years. In the …

 — An optimum mixture comprising 15% fly ash, 35% cement, and 50% radioactive waste sludge could provide the solidification required for long-term storage and disposal. The codisposal of radioactive fly ash with radioactive sludge by solidification decreases the usage of cement in solidification process.

 — When combustion is completed, the naturally occurring radioactive materials mostly end up in fly ash, bottom ash and boiler slag slagByproduct left after a desired metal is thermally separated from its …

 — Burning coal in boilers to create steam for power generation and industrial applications produces a number of coal combustion residuals. Naturally radioactive materials that were in the coal mostly end up in fly ash, bottom ash and boiler slag slagByproduct left after a desired metal is thermally separated from its raw ore..These …

 — Assessment of the radiation exposure from fly ash is critically dependent on the concentration of radioactive elements in the parent coal and in the fly ash that remains after combustion. During coal combustion, most of U, Th and their decay products are released from the original coal matrix and are distributed between the gas phase and the ...

 — The sentence marked with an asterisk was changed from "In fact, fly ash—a by-product from burning coal for power—and other coal …

 — If all the fuel were to be released from a nuclear station it would be far more in quantity and more hazardous than the total amount of radioactive fly ash that could ever be emitted from a coal ...

 — Samples of a specific backfilling fly ash-pozzolanic-cement mortar, were immersed in a simulated radioactive liquid waste very rich in sulphate (2.05 M) and sodium (4.1 M) ions. In addition to the mechanical behavior, the changes of the microstructure characteristics of the mortar were evaluated by X-ray diffraction (XRD), mercury intrusion ...

tory classification of fly ash as nonhazardous solid waste. Maximum allowable concentrations under these tests are 100 times drinking water standards, but these concentration limits are rarely approached in leachates of fly ash. The leachability of radioactive elements from fly ash has relevance in view of the U.S. Environmental …

 — Huge quantities of fly ash and bottom ash are generated from thermal power plants and it presents great concern for country, mainly due to the environmental effects. …

 — Coal fly ashes are collected by cyclone or electrostatic separators [].Quintana et al. [] found that activity concentration of radionuclides in coal fly ash is higher than that in coal bottom ash formed in the same boiler of the power plant.This fact can be justified because the radioactive elements are concentrated preferably on the coal fly …

 — Generally, fly ash is not rich in radioactive elements. On an average in most of the fly ashes presence of Uranium and Thorium is observed. The concentration of Uranium may vary from 15 to 110 mg/kg and Thorium is about 10–25 mg/kg. These radioactive elements are present in finer sized particles of fly ash.

Because of coal nature, fly ash represents a significant drawback with presence of radionuclides such as 226 Ra, 232 Th and 40 K. The fly ash can be used for various applications. The main amount of the fly ash is used for building materials production as cement additive and concrete production.

 — Fly ash that is not reutilized can be stored in designated facilities. However, according to research by Greenpeace, many fly ash storage conditions in China do not meet the minimum standards, ... Radioactive elements in coal ash mainly exist in three forms: i) the silicate-bound form in which most radioactive elements are combined with …

 — Radioactive Elements in Coal and Fly Ash: Abundance, Forms, and Environmental Significance January 1, 1997 View Document. Coal is largely composed of organic matter, but it is the inorganic matter in coal—minerals and trace elements— that have been cited as possible causes of health, environmental, and technological …

Soluble and insoluble radioactive cesium in municipal solid waste incineration fly ash were analyzed by X-ray diffraction and gamma-ray spectrometry. A total of 60% of soluble radioactive cesium was determined using the Tessier extraction method, and it was almost same extraction rate with Japanese …

 — Geopolymer paste + fly ash, replacing Eco-friendly cement, is an effective gamma radiation shield. • Superior Gamma-Ray Shielding by Geopolymer paste with a lower half-value layer variation (4.101 cm) and the highest mass attenuation coefficient (0.169 cm⁻ 1). Geopolymer paste with 1:3.3 sodium silicate led to a 20% increase in …

Radioactive elements from coal and fly ash may come in contact with the general public when they are dispersed in air and water or are included in commercial products that contain fly ash. The radiation hazard from airborne emissions of coal-fired power plants was evaluated in a series of studies conducted from 1975–1985.

 — Fly ash from the 4th thermal power station of Ulaanbaatar city has two drawbacks to its use as a raw material for producing geopolymers suitable for construction applications; these are its high radium equivalent radioactivity resulting from the radioactive Mongolian coal burnt in this power station (314–343 Bq/kg), and its high CaO content …

 — Bottom ash and fly ash are the leading solid waste of coal combustion in a typical coal-fired power plant (CFPP), and coal burning is the process of enriching some …

 — The operation of nuclear power plants generates a large amount of low- and intermediate-level radioactive waste liquid. Zeolite-rich geopolymers, which are synthesized under hydrothermal conditions from industrial waste fly ash, can effectively immobilize radioactive nuclides. In this study, the synthesis law of zeolite-rich geopolymers and the …

 — Coal fly ash has been described as being more radioactive than nuclear waste . Moreover, many of the most toxic elements are enriched in the PM 2.5 component of coal fly ash [ 25 ]. Whether or not the coal fly ash used for geoengineering is selectively enriched in PM 2.5 is not known, but enrichment in the small particle size fraction would …

 — The codisposal of radioactive fly ash with radioactive sludge by solidification decreases the usage of cement in solidification process. By this method, radioactive fly ash can become a valuable ...