Circulating fluidized bed fly ash (CFBFA) is a solid waste product from circulating fluidized bed (CFB) boilers in power plants, and the storage of CFBFA is increasingly become an environmental problem. Previous scholars have made contributions to improve the resource utilization of CFBFA. Especially, ecological cement is prepared …
The motion track of desulfurized fly ash in flue gas was simulated by means of Fluent software. The abrasion and deposition of desulfurized fly ash to inner surface and other internals inside of dense flow absorber were studied. The results show that, under the simulated condition, the flue gas streamline is uniform inside of dense flow absorber …
The binders used in the test included Portland blast furnace slag cement (P325) and fly ash (FA). The main composites of both cement and fly ash were CaO, SiO 2, Al 2 O 3 and Fe 2 O 3, as determined by X-ray fluorescence, and are shown in Table 2.Based on ASTM C618 [8], the used fly ash can be classified as F for the total content …
The characteristics of fly ash from the flue gas desulfurization (FGD) system are important for its reuse and are mainly depend on the desulfurization process. The …
The dispersion of fly ash in water results in an alkaline pH from 10 to 13. At high pH, the fly ash becomes negatively charged allowing the removal of heavy metal ions by precipitation and electrostatic adsorption from water (Cho et al., 2005). Fly ash can be modified or transformed into new materials for heavy metal ions adsorption.
Recently, the steel slag-fly ash-desulfurized gypsum (SS-FA-DG) composite system was developed as a novel building cementitious material, however, its reaction mechanism and reaction process mains unclear. This paper investigated the reaction kinetics of SS-FA-DG composite system by evaluating the influence of curing …
Wansom et al. calcined FGD gypsum into flue gas desulfurized plaster, mixed it with fly ash and ordinary Portland cement to expand its applicability, improving its water resistance and compressive strength and minimizing the risk of sulfate attack under wet conditions (Wansom et al., 2019). Utilizing the excellent water performance of FGD ...
Fly ash (FA), a residue from coal burning processes, is one of the most commonly used SCMs as an OPC replacement, with traditional replacement levels of 15%–50% by mass. ... Utilization of low-quality desulfurized ash from semi-dry flue gas desulfurization by mixing with hemihydrate gypsum. Fuel, Volume 255, 2019, Article …
In plants using flue gas desulfurization (FGD) processes, fly ash could contain high amounts of sulfur oxides, making its use in concrete inadvisable. However, …
Fly ash (FA) is the principal industrial waste byproduct from the burning of solid fuels. FA is a powdery solid that is constituted mostly of unburned carbon (UC), …
Calcium-based desulfurization ash (CDA) is mainly produced in dry and semi-dry flue gas desulfurization processes. The property of CDA is extremely unstable …
The fly ash generated from the burning of low sulfur coals is featured by high alkalinity, which alone or mixed with CaCO 3 can be used as the absorbent for desulfurization. The desulfurization performance of fly ash and CaCO 3 compound absorbent is experimentally investigated in a bubbling desulfurization reactor. Results …
Desulfurized fly ash (DFA) is a byproduct derived from the tail gas purification of coal burning, which is composed of about 85% CaSO 3 and Ca(OH) 2 . China generated 130 million tons of DFA in 2019. …
A common type of non-compliant fly ash (with SO 3 wt% >5.0 as per ASTM C618) is that contains semi-dry and dry flue gas desulfurization (FGD) impurities (e.g., S-bearing compounds), which increased substantially after enforcement of the Mercury and Air Toxics (MATS) rule in the United States in 2015 (DeVilbiss and Ray, 2017). Coal …
This paper presents the strength, durability and microstructural characteristics of fly ash based geopolymer concrete in addition to red mud. The study explores the influence of other parameters on the compressive strength of GC such as Na2SiO3 to NaOH ratio (liquid-to-liquid), and alkaline solution to binder ratio. The presence of high …
The potential use of flue gas desulfurization fly ash (FA-FGD) as a supplementary cementitious material (SCM) in concrete was analyzed in terms of performance in mortar samples and compared with those obtained with electrostatic precipitator desulfurization fly ash (FA-EPD) with the addition of gypsum (CaSO 4 ·2H 2 …
Fly ash was washed with deionized water, dried, ground, and sieved through a 200-mesh screen. 5 g of fly ash was evenly spread on the discharge area using a spoon at a time.
Fly ash has the potential to be used as the precursor in the acid-activated geopolymer preparation, fly ash can react with phosphorus-containing activators to form geopolymers, but different types of activators present different activation effects on fly ash. In this study, common liquid phosphoric acid (PA), liquid aluminum dihydrogen ...
1. Uses of Fly Ash in Cement and Concrete 2. Effect of Fly Ash on the Properties of Fresh Concrete 3. Effect of Fly Ash on the Structural Properties of Hardened Concrete 4. Admixtures in Fly Ash Concrete 5. Miscellaneous Opportunities for Fly Ash Use 6. Fly Ash Usage in Waste Management 7. Special Problems Including Use …
Downloadable! In this study, the catalytic effects of desulfurized fly ash (DFA) on the gaseous products of sawdust (SD) pyrolysis were investigated in a tubular furnace. The results indicated that DFA catalyzed the process of SD decomposition to improve the hydrogen content and the calorific value of pyrolysis gas. As to its effect on pyrolysis …
The fly ash result from coals burning and ultra fine fly ash is captured with cyclones help. There were made experimental researches on mixtures realized with ultra fine fly ash (from Timisoara ...
To resolve the limited large-scale methods of disposal of low calcium fly ash with poor activity, based on the double excitation principle, clinker and desulfurized gypsum are used as alkali/salt activators to …
Calcium-based desulfurization ash (CDA) is mainly produced in dry and semi-dry flue gas desulfurization processes. The property of CDA is extremely unstable because its main component, calcium sulfite, makes it difficult to be directly applied to the field of building materials. The modification of desulfurization ash can be realized by …
1. Introduction. For many years, the incorporation of fly ash as partial replacement of cement in concrete is a common practice. The quantity of fly ash to replace the cement for typical application is limited to 15–20% by mass of the total cementitious material [1].As a by-product of industrial process, the utilization of fly ash has made …
Red mud (RM), fly ash (FA) and desulfurized gypsum (DG) are harmful solid wastes that need to be treated. In this study, RM, FA, DG were used as the main raw materials to prepare road base materials based on the different (CaO + Na 2 O)/(SiO 2 +Al 2 O 3) molar ratio, and its mechanical properties, durability, microstructure and …
Semantic Scholar extracted view of "Development of green binder systems based on flue gas desulfurization gypsum and fly ash incorporating slag or steel slag powders" by Tian Wang et al. Skip to search form ... the catalytic effects of desulfurized fly ash (DFA) on the gaseous products of sawdust (SD) pyrolysis were investigated in a …
The experiments of the fly ash recycle combustion using Guizhou anthracite were carried out in a bench scale circulating fluidized bed (CFB) combustor. Effects of some key …
Circulating fluidized bed combustion (CFBC) power generation technology is known to efficiently reduce the emission of air pollutants, such as SO 2 and NO 2, from coal combustion. however, CFBC coal ash contains …
Circulating fluidized bed (CFB)-based coal burning technology is a type of clean coal combustion technology. Owing to its characteristics of low temperature …
Recycling industrial solid waste for mine backfill is one of the best ways to achieve green production in multiple industries. In this paper, the desulfurization gypsum (DG) as an activator is combined with the modified magnesium slag-fly ash cementitious paste backfill (MFPB) technology for the co-disposal of solid waste and goaf treatment, …
