Utilization Of Fly Ash Research Articles

Flame retardancy and high-value utilization of industrial solid waste fly ash in cellulose materials

Flame retardancy and high-value utilization of industrial solid waste fly ash in cellulose materials

Degradation of PCDD/Fs from incineration of waste at low temperatures for resource utilization of fly ash

Municipal solid waste incineration fly ash (MSWIFA) is of great value in resource utilization. Harmless pretreatment is a crucial prerequisite for the resource utilization of MSWIFA. The detoxification process is a crucial step in the harmless pretreatment of MSWIFA. This includes polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), which are among the most toxic substances to humans and other living organisms. Low-temperature degradation technology has broad prospects in engineering applications due to the advantages of low technical difficulty and operating costs. This work conducts a pilot test on the degradation of 17 toxic PCDD/Fs in MSWIFA at low temperatures. The pilot test investigates the effects of reaction temperature and oxygen content on the degradation of PCDD/Fs in MSWIFA. Furthermore, based on the perspective of MSWIFA resource utilization, an analysis and a proposal are made to judge the degradation effect of low-temperature thermal treatment technology on PCDD/Fs in MSWIFA. Further, taking the soil sludge field as the application scenario, the application feasibility of MSWIFA after detoxification is analyzed. The flotation process markedly reduces both the carbon content and the levels of PCDD/Fs in MSWIFA. The hydrothermal method facilitates the degradation of dioxins in fly ash while introducing oxygen significantly lowers the reaction temperature required for fly ash treatment. This can enhance the degradation rate and reduce the demands on reaction equipment. The results indicate that the low-temperature thermal treatment technology can effectively degrade PCDD/Fs in MSWIFA, satisfying the requirements of some application scenarios. Notably, evaluating the effect of low-temperature thermal treatment technology on the degradation and detoxification of PCDD/Fs in MSWIFA should satisfy the residue requirements of different industries and achieve a certain detoxication efficiency.

Optimizing Fly Ash Utilization in Construction: A Simulation-Based Approach to Enhance Sustainability

In light of the ever-increasing environmental footprint of conventional concrete production, particularly its carbon emissions and energy consumption, a search for alternative, more environmentally friendly options have been initiated. Fly ash is one such alternative derived from the combustion of coal, which has significant potential to decrease the environmental impact of concrete. This study aims to explore the compressive strength, carbon emissions, cost, and energy consumption of concrete when cement is partially replaced by different percentages of fly ash. The performance of fly ash-based concrete with replacement levels from 0% to 50% was evaluated using a simulation-based approach. In the results, there is linear reduction in compressive strength with an increase in fly ash content, but also there are immense reductions in carbon emissions by 46% and energy consumption by 33%. The cost of producing concrete was found to reduce with higher replacement levels of fly ash, indicating a potential for cost-effectiveness in high-scale construction works. The results thus show that fly ash-based concrete may present an efficient option for sustainable construction, reconciling environmental gains with economic viability. This work sets the ground for further studies to optimize fly ash use in concrete to increase its sustainability and performance.

Optimizing Fly Ash Utilization in Construction: A Simulation-Based Approach to Enhance Sustainability

Abstract: In light of the ever-increasing environmental footprint of conventional concrete production, particularly its carbon emissions and energy consumption, a search for alternative, more environmentally friendly options have been initiated. Fly ash is one such alternative derived from the combustion of coal, which has significant potential to decrease the environmental impact of concrete. This study aims to explore the compressive strength, carbon emissions, cost, and energy consumption of concrete when cement is partially replaced by different percentages of fly ash. The performance of fly ash-based concrete with replacement levels from 0% to 50% was evaluated using a simulation-based approach. In the results, there is linear reduction in compressive strength with an increase in fly ash content, but also there are immense reductions in carbon emissions by 46% and energy consumption by 33%. The cost of producing concrete was found to reduce with higher replacement levels of fly ash, indicating a potential for cost-effectiveness in high-scale construction works. The results thus show that fly ash-based concrete may present an efficient option for sustainable construction, reconciling environmental gains with economic viability. This work sets the ground for further studies to optimize fly ash use in concrete to increase its sustainability and performance.

Utilization of municipal solid waste incineration fly ash with different pretreatments with gold tailings and coal fly ash for environmentally friendly geopolymers.

Municipal solid waste incineration fly ash (MSWIFA) is considered a hazardous solid waste, traditionally disposed by solidified landfill methods. However, solidified landfills present challenges with leaching heavy metals, polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). To address this issue, this study examined two pretreatment methods for MSWIFA: sintering at 850℃ for 30 min and washing with three water baths (20 min each) at a 3:1 liquid-solid ratio. Then, the pretreated MSWIFA was employed in geopolymer synthesis, along with gold tailings (GT) and coal fly ash (CFA). The optimal raw material ratio was GT:CFA:MSWIFA = 5:4:1 after pretreatment, which resulted in maximum compressive strengths of 20.95 and 25.87 MPa for the sintered and washed samples, respectively. Washing removed 87.3 % of soluble chlorides from MSWIFA, enhancing the compressive strength of the geopolymer. High-temperature treatment effectively reduced the leaching concentrations of heavy metals and the toxic equivalent quantity (TEQ) of PCDD/Fs. The leaching concentrations of heavy metals (Cu, Zn, Cd, Pb) and the TEQ of PCDD/Fs were all below the limits established by Chinese standards GB 5085.3-2007 and HJ 1134-2020. X-ray Diffraction, Fourier transform infrared spectrometry, scanning electron microscopy, and energy dispersive spectroscopy analyses revealed that the primary hydration products of the geopolymer are C-(A)-S-H gels. Washing treatment facilitated the formation of ettringite and Ca(OH)2, which enhanced the pore structure and optimized the performance of the geopolymer. Thermogravimetric analysis revealed the good thermal stability of the geopolymer, indicating that the high-temperature and washing pretreatments minimally impacted its thermal stability.

Enhancing the sustainability of geotechnical engineering with utilization of fly Ash

Abstract Massive amounts of fly ash (FA) are dumped carelessly leading to a negative influence on the environment. However, FA contains several advantages when it is used in geotechnical engineering and civil engineering projects which not only dispose of waste but also improve sustainability. In addition to offering a promising solution to the disposal issue, the use of waste materials in civil engineering projects also offers an affordable substitute for conventional materials which preserves natural resources. Many scholars' studies show how FA is used and how it affects the geotechnical characteristics of the soil. Despite extensive research, the assessment of FA's suitability is complicated due to the chemical composition of FA which varies significantly between sources. This variability can affect how FA interacts with different soil types, leading to inconsistent results in terms of soil improvement and geotechnical properties. Therefore, a comprehensive review is required that compiles all effective data and gives the user simple instructions about using FA. This article reviews the current state of the art research on the physical properties of FA, chemical composition of different countries FA, Atterberg limit, compaction properties, California bearing ratio, unconfined compressive strength, shear strength compression, and swelling index. Results showed that adding FA to soil increased its geotechnical qualities, but the effect depends on the type of soil and specific conditions, such as moisture content, compaction, and the percentage of FA added. The higher percentages of FA led to a decline in geotechnical characteristics. The assessment, therefore, advises that FA may be added up to optimum percentages which generally 20% depending on its source and chemical composition.

Utilization of asphalt waste Dust and fly ash for sustainable mortar

Utilization of asphalt waste Dust and fly ash for sustainable mortar

Study on whitening of fly ash coated by three precipitation coating methods

This study investigates the high-value comprehensive utilization of fly ash (FA) through a whitening process using three precipitation coating methods, namely BaSO4, CaCO3 and Mg(OH)2. Various key parameters were investigated, including titration method, coating amount, solid-liquid ratio, reaction time and reaction temperature, and the relevant theories and mechanisms were systematically analyzed. The experimental results showed that the highest whiteness of the coated powders was obtained when pretreated with 5 mol/L hydrochloric acid for iron removal and 600°C for carbon removal, dripping with salt and alkali at the same time, a coating amount of 100%, a solid-liquid ratio of 1:6, 1:8, and 1:10 g/mL, respectively, a reaction time of approximately 30-40 minutes, and a reaction temperature of 60°C. Characterization results obtained by XRD, XRF, BET and SEM-EDS analyses confirmed that the precipitated crystals nucleated and grew on the FA surface during the cladding experiments, thus increasing its whiteness.

Assessment of fly ash waste utilization in cement production: Implications for air quality and sustainability

Background: Growing national development and energy consumption increase reliance on coal, a non-renewable resource. In Indonesia, coal mainly fuels electricity generation, producing significant fly ash waste. This study evaluates the environmental impacts of using hazardous and non-hazardous fly ash in cement production. Methods: This research employs a quantitative approach, focusing on fly ash utilization in cement production. Conducted at PT ABC, it analyzes emissions from five chimneys and ambient air quality, using AERMOD modeling and Continuous Particulate Monitoring for data collection and analysis. Findings: PT ABC has tested fly ash waste from 2018 and 2022 as a substitute for cement raw material, meeting the necessary specifications for both hazardous (B3) and non-hazardous (non-B3) categories. TSP emission data from 2022 were modeled using AERMOD, considering meteorological conditions and chimney emissions. The worst-case scenario for 24-hour particulate dispersion showed compliance with ambient air quality standards, indicating effective management of air pollution at PT ABC. Conclusion: Fly ash utilization at PT ABC maintains air quality standards without significant decline. Novelty/Originality of this Study: This study comprehensively assesses fly ash waste management in cement production, utilizing AERMOD modeling to demonstrate compliance with environmental standards and promoting sustainable practices while addressing Indonesia's critical environmental challenges.

Mechanical Properties of High-Volume Fly Ash Mortar Modified by Hybrid Carbon Nano Tube and Graphene Oxide

The effect of combined nano materials on mechanical properties of high-volume fly ash mortar (HVFAM) was carried out in this investigation. The characteristics of HVFAM mixes were first evaluated using slump flow tests. Then, the mechanical properties of HVFAM including the measurement of setting time and the development of early-age compressive strength were performed. Structural changes during hydration were analyzed using FTIR analysis. The study utilized fly ash (FA) as a 60% replacement for cement, with the addition of 0.01% carbon nanotubes (CNT) and graphene oxide (GO) with five different dosages ranging from 0.01% to 0.05%. Results of study showed that the incorporation of hybrid CNT and GO significantly affected the mechanical properties of HVFAM. Specifically, increased of CNT and GO contents lead to significant reduction in both workability and setting time of HVFAM, with a more pronounced reduction in final setting time compared to initial setting time. The development of early-age strength of HVFAM improved by 15.8% with the highest 28 day-strength increasing by approximately 23% at 0.01% CNT and 0.03% GO dosages. FTIR analysis confirmed that the improved early-age strength was attributed to the accelerated hydration of cement caused by the seeding effect. The outcome of the study provides a suitable approach for the development of eco-friendly materials with improved mechanical properties that could be effectively used for HVFAM.

Mechanistic study on the utilisation and mineral formation of incineration fly ash in sintering

Fly ash, a significant byproduct of municipal solid waste incineration, garners attention for its harmless treatment and resource utilisation. Existing research has demonstrated the viability of incorporating fly ash into the sintering process and explored its influence on the sintering bonding phase. In the context of co-disposal of municipal solid waste incineration residues through sintering, it is imperative to consider the mineralisation characteristics, necessitating a comprehensive evaluation of sinter strength and metallurgical performance. In this investigation, the process is validated on an expanded scale using sintering cup experiments. The results indicate that the experimental group with a basicity of 2 and the inclusion of fly ash exhibits sinter strength in line with actual production requirements, its drop index is 76.03%, and its drum index is 77.2%. Additionally, the reduction velocity index is recorded at 0.573% min−1, the reduction degradation index for RDI+3.15 at 92% and the total characteristic value of melting properties ( S) at 99.175 KPa·°C—nearly equivalent to the control group with matching alkali conditions. The technology roadmap was verified by sintering cup experiment, offering vital theoretical support for the development of sintering process in the collaborative treatment of incineration fly ash.

Sustainable dual-edged utilization of fly ash for growth improvement of black gram (Vigna mungo L.) and management of Meloidogyne incognita

Sustainable dual-edged utilization of fly ash for growth improvement of black gram (Vigna mungo L.) and management of Meloidogyne incognita

Thermal Characteristics of Fly Ash-Slag Based Geopolymer Concrete for Sustainable Road Construction in Tropical Region

AbstractGeopolymer cement is an emerging eco-friendly alternative to traditional Portland cement that offers a lower carbon footprint and the opportunity to use of industrial by-products such as fly ash and slag in its production. Although acknowledged as a dependable structural material in various studies, the potential of Geopolymer Concrete for paving applications remains under-explored. This research aimed to address this gap by developing Paving Quality Geopolymer Concrete (PQGC) and examining its mechanical and thermal properties. For applications in tropical climates, where the pavement surface may be subjected to temperatures in the range 30–60 °C, studies on thermal conductivity (λ), coefficient of thermal expansion (α), and stresses caused by daily and seasonal temperature changes in PQGC slabs need to be essentially studied. The study revealed that thermal conductivity of PQGC ranged from λ = 0.82 W/(m°C) to 0.71 W/(m°C) within the temperature range of 30–60 °C. The coefficient of thermal expansion for PQGC was evaluated using a setup based on AASHTO T 336–15 recommendations, and it was found, α = 8 × 10–6/°C, to be lower than that of Pavement Quality Concrete (PQC). Furthermore, stresses resulting from temperature fluctuations in PQGC, when computed using closed form solution and EverFe 2.26, were observed to be lower than those in PQC. Finally, PQGC has the potential to contribute to a cooler environment by emitting less heat into its surroundings and promotes the utilisation of fly ash and slag, making it a promising material for paving applications.

Utilization of fly ash and bottom ash (faba) and oil palm empty fruit bunch on the characteristics of red bricks

Abstract Fly Ash and Bottom Ash (FABA) is waste from coal combustion originating from Steam Power Plants. This waste has chemical content in the form of silica, aluminum oxide, and lime. Previous research stated that Oil Palm Empty Fruit Bunch can increase the mechanical strength of the building material and prevent the propagation of cracks due to loads. The use of additional ingredients FABA and Oil Palm Empty Fruit Bunch in the red brick mixture aims to determine the characteristics of red brick in the form of compressive strength and water absorption values. The test was carried out at the Civil Engineering Laboratory at Bangka Belitung University using 100 red brick samples. The percentage of FABA used in this research is 10% (5% fly ash and 5% bottom ash) calculated from the weight of the clay, while the percentage of Oil Palm Empty Fruit Bunch used is 0%, 5%, 10%, and 15% is calculated from the weight of the clay. The results of this test show that red bricks with the addition of 10% (5% fly ash and 5% bottom ash) FABA and 0% Oil Palm Empty Fruit Bunch increased the compressive strength value of normal red bricks and can reduce water absorption.

Utilization of fly ash composite from municipal solid waste incineration (MSWI) as an adsorbent to remove methylene blue from wastewater

Abstract Utilization of MSWI fly ash and corncob by combining fly ash and corncobs with a 1:10 ratio, activated with 75% KOH as an adsorbent to reduce methylene blue dye in textile wastewater. For the characterization testing of FACC, SEM-EDS, and pHpzc were used to determine the morphological conditions and pH value when FACC is in zero charged condition. Characterization results show that FACC has a rough surface and many pores with O, C, and K as dominant elements. pHpzc test shows that FACC will have a zero charge at pH 13.18. Experiments were conducted with batch method on the effect of adsorption operational parameters at contact time (0-120 min), FACC dosage (0.05-0.5 g/L), pollutant concentration (50-250 mg/L), and initial pH (2-10). Maximum removal efficiency was obtained at a contact time of 60 minutes, with a dosage of 0.5 g/L, pollutant concentration of 50 mg/L, and initial pH of 4 with a removal % of 98.37%. The Langmuir isotherm model described the adsorption mechanism with the maximum adsorption capacity reaching 344.828 mg/g. The adsorption rate used a pseudo-second-order kinetics model with a K2 value of 13.9 × 10−3 g/mg.min. FACC are good adsorbent alternatives for removing dyes in industrial wastewater.

Long-term evaluation of FABA utilization to prevent AMD generation – a review of barrel kinetic test

Abstract The utilization of fly ash and/or bottom ash (FABA) to prevent the generation of acid mine drainage is present in several mining companies to maximize geochemical and geotechnical potentials of FABA. Geochemically, FABA has the potential as a neutralizing material due to its high acid-neutralizing capacity, therefore it can be used as a sealing material for the potentially acid-forming (PAF) overburden in coal mining activities, which has the potential to produce acid drainage. This study aims to ensure that the potential leachate runoff at PAF disposals through neutralizing and sealing is not in acidic condition. A series of kinetic geochemical tests were carried out using a 200-liter volume column, applying various compositions of non-acid forming (NAF) rocks, a mixture of FABA, and PAF to ensure the method reliability. Leachate leaking out of the column was subjected to pH and EC analysis. The test results for a period of 3 years (Jan 2021 – June 2024) showed that the NAF-PAF-FABA sealing system produced a neutral pH compared to the FABA-PAF and NAF-FABA-PAF-NAF sealing. The position of FABA under the PAF layer triggered the carbonate released by acidic water, enabling neutralization. The 9:1 ratio of FA to BA in NAF-PAF-FABA sealing system showed better results than 4:1 ratio, indicative of greater neutralizing capacity of FA than BA. Compositions with smaller amounts of PAF produced better results due to less potential acidity that must be neutralized.

Utilisation of Class-F fly ash in xanthan gum–amended neutral or acidic soils

Xanthan gum (XG) is an eco-friendly biopolymer with potential applications in soil amendment. However, in acidic soil environments, the pyruvate groups and glycosidic bonds in XG molecules tend to hydrolyse, thereby weakening the efficacy of soil improvement. In this study, the feasibility of utilising alkaline Class-F fly ash (FA) to assist XG in reinforcing acidic soils was evaluated through proctor compaction, unconfined compression, and one-dimensional consolidation. With the increasing soil acidities, the beneficial effect of FA on the geotechnical performances of XG-amended soils grew. The improvement in both mechanical strength and compressibility of XG-amended acidic soils might be caused by the crossing-linking of XG molecular strands and the mitigated hydrolysis of XG hydrogels due to the presence of FA. Based on the findings, it is suggested to use FA in combination with XG for treating the acidic soils and use XG alone for treating the neutral soils. The research outcomes will promote the reuse of solid waste Class-F FA in sustainable geotechnical engineering practices, for example, biopolymer-based soil amendment in acidic soils.

Utilization of Portland Cement and Fly Ash for Treatment of Mercury Polluted Soil through Stabilization/Solidification

Abstract Traditional gold mining contributes significantly to soil mercury pollution. Stabilization/Solidification (S/S) Technology offers a remediation solution for soils contaminated with heavy metals. Besides the low cost of the technology, the S/S technology can be carried out in situ and ex-situ with material pozzolanic properties, such as Portland cement and fly ash, effectively bind these metals. This study aims to identify the proportion of mercury-contaminated soil mixed with a combination of Portland cement and fly ash. Artificial soil samples with a mercury content of 150 mg/kg were used, and test specimens were formed into 5 cm cubes. In the first phase, different ratios of Portland cement to fly ash were tested: 100:0, 90:10, 80:20, 70:30, 60:40, and 50:50. The second phase focused on the optimal mix ratio based on compressive strength tests for combinations of Portland cement and fly ash with mercury-contaminated soil, with the same ratios as in the first phase. Subsequent compressive strength and specimens were tested using the Toxicity Characteristic Leaching Procedure (TCLP). The first phase identified the optimal 50:50 ratio of Portland cement to fly ash, achieving a compressive strength of 5559 tons/m2. In the second phase, the same 80:20 ratio for the mix of Portland cement, fly ash, and mercury-contaminated soil yielded a compressive strength of 2902 tons/m2 and a TCLP result of 0.0062 mg/L. All samples met the criteria set by the United States Environmental Protection Agency (US EPA), with variations ranging from 17 MPa for residential concrete to 28 MPa and the TCLP-B quality standard. According to Regulation by Government No. 22 of 2021, the permissible concentration is 0.05 mg/L. The study concludes that increasing the proportion of soil and fly ash Included in the mixture reduces the quality of S/S products.

Provision of Standards to Support the Potential Utilisation of Fly Ash and Bottom Ash from Coal-Fired Power Plants for Wastewater Treatment

Provision of Standards to Support the Potential Utilisation of Fly Ash and Bottom Ash from Coal-Fired Power Plants for Wastewater Treatment

Exploring the Use of Fly Ash and Marble Coarse Aggregates as Eco-Friendly Replacements in Concrete Production

Abstract This study investigates the feasibility of utilizing fly ash and marble coarse aggregates as sustainable substitutes in concrete production, responding to the increasing demand for infrastructure and the necessity to diminish the carbon footprint of construction materials. By partially substituting cement, a material that generates substantial greenhouse gas emissions, fly ash, a by-product of coal combustion, recognizes its capacity to reduce CO2 emissions. The stone processing industry produces marble waste, which, by repurposing otherwise wasted byproducts, offers an environmentally sustainable solution, simultaneously reducing the use of natural resources in the manufacture of traditional aggregates. The research aims to assess the effects of incorporating various ratios of fly ash, ranging from 10% to 50%, and marble coarse aggregates, ranging from 10% to 90%, on the workability, compressive strength, split tensile strength, and flexural strength. The results show a moderate decrease in a slump, with an 18.66% reduction at 50% marble coarse aggregates and 30% fly ash, and a significant increase in compressive strength, with a 60.22% improvement at 56 days with 40% fly ash and 70% marble coarse aggregates. Split tensile strength also improved by 35.50% to 36.66%. Non-destructive tests confirmed the structural integrity of the concrete. This study emphasizes the potential of fly ash and marble coarse aggregates as eco-friendly substitutes in concrete production.