Supercritical CO2 coupled with water washing to enhance …
The high chlorine content in municipal solid waste incineration (MSWI) fly ash is a key factor restricting its treatment and disposal. In this study, a new treatment method was proposed to enhance the deep dechlorination of fly ash by coupling supercritical CO 2 (SC) treatment with water washing. Simultaneously the alkaline compounds in fly ash can fix CO 2 and achieve CO …
Evaluation of chlorides in fly ash for use in concrete
The results borne from this research prove that the use of fly ash with chloride content below 0.25% performs better than concrete mixtures without fly ash. Accordingly, the …
Effects of Fly Ash Inclusion and Alkali Activation on Physical
The UCS of the soil increased with the addition of alkali activators, fly ash content, and the curing time. The highest UCS result was found with 25% fly ash content, M+ of 16% and SM of 1.25 at 28 days of curing which can improve the …
Preparation of municipal solid waste incineration fly ash/ …
Besides, as a lightweight aggregate, the ceramsite chlorine content has to meet the relevant National Standard (GB/T17431.1––2010). Thus, it is meaningful and critical to explore the release and migration of chlorine during the preparation of MSWI fly ash/GSM ceramsite (abbreviated to MG ceramsite), and confirm the type and content of ...
The influences of MSWI fly ash washing and blast furnace …
Incineration power generation technology, capable of reducing volume and weight of waste by 90% and 70%, respectively (Huang et al., 2017), emerged as a prominent method for disposing municipal solid waste (Verbinnen et al., 2017).In the grate-firing (GF) incineration system, complete combustion was achieved through the mechanical movement of the grate, …
Development of an eco-friendly geopolymer mortar using slag and fly ash
Characterization experiments The mechanical testes of eco-friendly ternary geopolymer mortar based on slag-fly ash-bentonite Drying shrinkage. To measure the drying shrinkage, mortars were made in ...
Influence of slag content on the bond strength, chloride …
When the slag content is 0% ( fly ash content), the chlorides resistance of the specimens was the worst, which was consistent with the conclusion reported by Thomas et al. [35] and Ismail et al. [41]. At this time, the amount of C-S-H gel adsorbed chlorides was greatly reduced, and the compactness of the material was reduced.
Characteristics and leaching behavior of MSWI fly ash in …
Specifically, pH value of MSWI fly ash was 12.37, and it was noncorrosive. The density of MSWI fly ash was up to 2350 kg/m 3, and surface area of MSWI fly ash was as high as 766 m 2 /kg, which was beneficial to leaching of heavy metals, and it also increased the risk of contamination to the environment (Pan et al., 2013, Weibel et al., 2016).
Alkali Content of Fly Ash Measuring and Testing …
Sodium and potassium are the common alkalis present in fly ash. Excessive amounts of fly ash alkalis can cause efflorescence problems in concrete products and raise concern about the …
Removal of chloride from MSWI fly ash
In several roasting experiments, the removal of chloride content from fly ash at 1050°C for 3h showed the best results (83% chloride removal efficiency). At a solid to liquid …
Experimental study on the washing characteristics of fly ash …
Raw fly ash contained high chlorine (Cl) with the maximum of 19.83% and it can be significantly reduced by washing. Double-washing and secondary-washing had better performance than …
Setting and Hardening Behaviour of Alkali-Activated Landfilled Fly Ash
The pH value of the alkali solution was increased by a higher Na 2 O content, which will promote the amount of dissolved fly ash and slag particles . As a result, more gels are formed to produce a denser structure, and the compressive strength is improved.
Double high-value utilization of valuable resources in the …
In China, approximately 10 million tons of municipal solid waste incineration fly ash (MSWI-FA) and 30 thousand tons of medical waste incineration fly ash (MWI-FA) were generated in 2022. The chemical compositions of MSWI-FA are rich in 40–50 % calcium, 20–30 % high in chlorine, and contains a certain amount of dioxin and heavy metals such ...
Structural behavior of alkali activated fly ash concrete. Part …
Alkali Activated Fly Ash Concrete (AAFAC) is an alternative form of concrete that uses fly ash as a 100 % replacement for ordinary portland cement. ... Acknowledgments The authors wish to thank the National Science Foundation under Award Number 0923818 for providing financial support for this project, and the Office of Research and Sponsored ...
Utilization of municipal solid waste incinerator fly ash under …
MSW incineration creates a variety of residual products, notably bottom ash and fly ash, which make up approximately 90 % and 5 % of all combustion leftovers, respectively [5].Currently, bottom ash is being repurposed in the reclamation of metals and the production of construction materials [6].Nevertheless, fly ash, which contains organic components high in …
Study on the Solidification/Stabilization of MSWI Fly Ash by …
Municipal solid waste incineration (MSWI) fly ash (FA) is a hazardous waste produced during the incineration of municipal solid waste, posing a risk of heavy metal leaching and threatening the environment. Therefore, the harmless treatment of MSWI FA has become a crucial issue in environmental safety treatment. This study utilized blast furnace slag, FA, and …
SIP 4 Restrictions on Type and Characteristics of Fly Ash
The [available] alkali content of fly ash shall not exceed X.X% In an NRMCA review of more than 100 specifications for private work, these types of restrictions were noted in 25% of the specifications, 80% of which did not al-low the use of Class C fly ash or had restrictions on the …
Use of Harvested Fly Ash in Highway Infrastructure tech …
ash, where Class F fly ash has a CaO content of 18 percent or less and Class C fly ash has a CaO content greater than 18 percent. For both classes, the specification indicates that the …
Removal of chloride from MSWI fly ash
The high levels of alkali chloride and soluble metal salts present in MSWI fly ash is worth noting for their impact on the environment. In addition, the recycling or reuse of fly ash has become an issue because of limited landfill space. The chloride content in fly ash limits its application as basi …
Treatment of municipal solid waste incineration fly ash: …
There are two main particulate by-products from MSWI, namely MSWI bottom ash (BA) and MSWI fly ash (FA) (Quina et al., 2014b, Verbinnen et al., 2017).The MSWI FA together with the reagents (mainly lime and powdered activated carbon) collecting from air pollution control () devices is referred to as residue (Ghouleh and Shao, 2018, Li et al., 2017a, Li et …
ASTM C618 Fly Ash Specification: Comparison with Other
However, the quantity of fly ash needed for alkali-silica reaction prevention depends on various concrete mixture parameters, including aggregate source and OPC alkali content, as well as fly …
Comprehensive understanding the transition behaviors and …
Municipal solid waste incineration fly ash is classified as the hazardous waste because of its high levels of heavy metals alkali chlorides, and polychlorinated dibenzo-p-dioxins. ... the variation of mass and content of chlorine and various metal ions were analyzed through diverse characterization methods under different sintering temperatures ...
A novel method for solidification/stabilization of MSWI fly ash …
Fig. 7 depicts that the main mineral composition in MSWI fly ash is chlorine-containing compounds and calcium-containing compounds, which include NaCl, KCl, Ca(OH) 2, CaClOH, CaCO 3 and CaSO 4. Especially, CaClOH was an intermediate product in the process of eliminating acid and had a certain hydration activity in an alkali environment [30].
Alkali Content of Fly Ash – Measuring and Testing Strategies …
Sodium and potassium are the common alkalis present in fly ash. Excessive amounts of fly ash alkalis can cause efflorescence problems in concrete products and raise …
Bio-treatment of municipal solid waste incineration fly ash: A
The pH value test method is according to GB/T15555.12-1995 (2020), as the standard specified that 10 g fly ash sample was placed to a conical flask and filled with 100 ml of deionized water. The suspension was shaken at room temperature for 8 h, after which it was left to stand for 16 h.
XRD and TG-DTA Study of New Alkali Activated Materials Based on Fly Ash
According to the Standard ASTM C618-92a, indigenous fly ash belongs to class F because it has a main oxides (silicon, aluminum and iron) sum that is higher than 70% (Equation (1)): ... it was observed that the mass lose percentage depends on the sample fly ash content. Therefore, the hygroscopicity, as well as the concentration of unstable ...
Alkali Content of Fly Ash – Measuring and Testing …
Sodium and potassium are the common alkalis present in fly ash. Excessive amounts of fly ash alkalis can cause efflorescence problems in concrete products and raise concern about the effectiveness of the fly ash to mitigate alkali-silica reaction (ASR). The available alkali test, which is commonly used to measure fly ash alkali, takes approximately 35 days for execution and …
Evaluation on reactivity of fly ash from different sources in alkali …
The aluminum content in fly ash is primarily found within the glassy phase and various crystalline constituents, including mullite and albite. ... internal composition of particles). The introduced R value, reflecting the reactivity of fly ash in alkali-activation processes, ranges from 4.52 to 24.90 in ... National Standard of the People's ...
Chlorides Removal and Control through Water-washing Process on MSWI Fly Ash
Bulk density of the fly ash is around 0.73g/cm3. Moisture content is about 4.22% and pH for the filtrate of the fly ash is about 12.72. Fly ash samples after grinding sieved through a 150-mesh standard sieve, then it was dried under 105ć after 8h to constant weight. ... The leaching amount of chlorine in the filtrates was calculated ...
A novel process for the desalination of MSWI fly ash via in …
With regard to MSWI fly ash washing, Chiang and Hu [21] reported that with a liquid-to-solid (L/S) ratio of 10, most of the leachable salts and amphoteric heavy metals in MSWI fly ash were removed.While in the findings of Yang et al. [13], the optimal L/S ratio for MSWI fly ash washing by fresh water should be 20:1 to 25:1.Considering the economic facts such as the …