Article
Construction & Building Technology
Yanli Wang, Jiao Ma, Longbang Qing, Lina Liu, Boxiong Shen, Shuhao Li, Zhikun Zhang
Summary: This study investigated the carbonation pretreatment of municipal solid waste incineration fly ash (FA) with different carbonate solutions to improve its recyclability by converting it to geopolymers with coal fly ash (CFA). The results showed that the carbonate solutions changed the mineral phases of FA and affected the properties of geopolymers. Geopolymers prepared with Na-FA exhibited the best performance, with a denser microstructure and better compressive strength.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Qixin Yuan, Yongsheng Zhang, Tao Wang, Jiawei Wang
Summary: Fly ash carbonation is a viable method for reducing CO2 emissions and stabilizing heavy metals. Physical encapsulation and chemical reactions are the main mechanisms for heavy metal stabilization. Supercritical CO2 and mechanical force enhance these mechanisms.
JOURNAL OF CO2 UTILIZATION
(2023)
Article
Green & Sustainable Science & Technology
David Suescum-Morales, Rui Vasco Silva, Miguel Bravo, Jose Ramon Jimenez, Jose Maria Fernandez-Rodriguez, Jorge de Brito
Summary: The effect of incorporating bottom ash from municipal solid waste incineration (MIBA) as partial replacement for fly ash (FA) on alkali-activated mortars was studied. The use of MIBA resulted in a decrease of calcium silicate hydrate gel (C-S-H) and sodium aluminosilicate hydrate (N-A-S-H), affecting the macrostructural behavior of the mortars. The accelerated CO2 curing stage improved the macrostructural behavior of the mortars.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Construction & Building Technology
Xiao-Chen Shi, Zhonghe Shui, Xunguang Xiao
Summary: Pretreatment is an important step in the accelerated carbonation process. Ultraviolet radiation was used as a pretreatment method to improve the carbonation performances of fly-ash cement paste in CO2 curing. The results showed that UV pre-treatment could decrease the water content and promote the natural carbonation of pastes, leading to increased CO2 uptake and carbonation depth. The use of UV pretreatment was more suitable for the carbonation of fly-ash cement at low CO2 concentration to improve the development of strength and CO2 uptake.
JOURNAL OF BUILDING ENGINEERING
(2023)
Article
Environmental Sciences
Nenad Popov, Srdan Roncevic, Natasa Dudukovic, Dejan Krcmar, Zeljko Mihaljev, Milica Zivkov Balos, Stefan Dordievski
Summary: This study applied a method combining EK and S/S treatments with accelerated carbonation, effectively reducing the volume of polluted sediment and ensuring the stabilized sediment can be safely disposed of.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2021)
Article
Construction & Building Technology
Mohammad Balapour, Thiha Thway, Newell Moser, Edward J. Garboczi, Y. Grace Hsuan, Yaghoob Farnam
Summary: This study characterizes the engineering properties of lightweight aggregate (LWA) manufactured from low calcium (F-FA) and high calcium (C-FA) waste fly ash. The properties examined include specific gravity, water absorption, porosity, pore size distribution, and permeability. The results show that the properties of the LWA are affected by the concentration of fluxing agent and all the LWA meet the water absorption requirements for internal curing of concrete.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Construction & Building Technology
Klara Krizova, Jan Bubenik, Martin Sedlmajer
Summary: This study investigates the resistance to high temperatures of lightweight concrete made with sintered fly ash aggregate. Different amounts of lightweighting were applied to the concrete samples, and their properties were tested after exposure to temperatures of 600, 800, and 1000 degrees C. The results show that increasing the degree of lightweighting can improve the compressive strength of the concrete up to 800 degrees C, but the strength increase decreases as the degree of lightweighting increases. At 1000 degrees C, the internal structure of the lightweight concrete becomes unstable, resulting in a significant decrease in compressive strength and the formation of spherical neoplasms that reduce the internal integrity of the cement matrix.
Article
Construction & Building Technology
Hamza Karakas, Serhan Ilkentapar, Ugur Durak, Ezgi Orklemez, Sumeyye Ozuzun, Okan Karahan, Cengiz Duran Atis
Summary: In this study, lightweight geopolymer mortar samples were produced using class F fly ash and different aggregates. The use of raw and expanded perlite as aggregates resulted in a decrease in unit weight, ultrasonic pulse velocity, flexural and compressive strengths, and an increase in water absorption and porosity. However, the thermal insulation performance and strength of the geopolymer mortar samples increased when using expanded perlite, especially at elevated temperatures of 900 degrees C.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Shunfeng Wang, Long Yu, Zheng Qiao, Hao Deng, Linglin Xu, Kai Wu, Zhenghong Yang, Luping Tang
Summary: With the development of urbanization and the economy, the amount of municipal solid waste incineration fly ash has increased. Researchers are paying attention to reducing the leaching concentration of heavy metals in this fly ash and expanding its application in wastewater and biosorption. Non-sintered light-weight aggregates (LWAs) were prepared using MSWI fly ash and coal fly ash as raw materials. The heavy metals in the LWAs were found to be immobilized through encapsulation and adsorption. The leaching rate and cumulative leaching rate of heavy metals were significantly affected by the leaching environment, with a lower rate observed at pH above 1. This research provides theoretical support for using non-sintered and MSWI fly ash-based LWAs in concrete.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Engineering, Environmental
Jie Chen, Yizhe Shen, Zhiliang Chen, Congkai Fu, Minjie Li, Tieying Mao, Ruiyang Xu, Xiaoqing Lin, Xiaodong Li, Jianhua Yan
Summary: Mechanical ball-milling is an effective technique to enhance the activity of materials. After modification, an accelerated carbonation technology of municipal solid waste incineration fly ash was proposed. The effects of ball-milling on carbonation efficiency, heavy metals stabilization, and leaching characteristics were investigated.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2023)
Article
Construction & Building Technology
Sundar Rathnarajan, B. S. Dhanya, Radhakrishna G. Pillai, Ravindra Gettu, Manu Santhanam
Summary: Supplementary cementitious materials (SCMs) can be used to enhance sustainability and reduce carbon footprint in the concrete industry. This study evaluated the carbonation resistance of various concretes and developed a more generic model to estimate carbonation coefficients. The results demonstrate that SCMs can be used to design concretes with comparable long-term carbonation depth as ordinary Portland cement (OPC) concretes.
CEMENT & CONCRETE COMPOSITES
(2022)
Article
Chemistry, Physical
Puput Risdanareni, Philip van den Heede, Jianyun Wang, Nele De Belie
Summary: The research found that using alkali-activated fly ash LWA in mortar can achieve equivalent mechanical strength to commercial expanded clay LWA, and exhibit excellent resistance to carbonation and chloride ion penetration.
Article
Construction & Building Technology
Pritam K. Pati, Shishir K. Sahu
Summary: This investigation focuses on producing lightweight fly ash angular aggregates (FAA) using local class 'F' fly ash in India and explores its potential as an alternative coarse aggregate in structural concrete applications. The FAA showed improved physical properties compared to commercially available fly ash pellets (FAP). Concrete containing FAA exhibited comparable strength parameters to conventional concrete, potentially due to the pozzolanic reaction between the fly ash angular aggregates and cement paste. The study suggests that FAA can be effectively utilized in RCC construction, reducing the dead load of structures while addressing fly ash disposal and mineral depletion issues.
ADVANCES IN CONCRETE CONSTRUCTION
(2022)
Article
Construction & Building Technology
David Suescum-Morales, Miguel Bravo, Rui Vasco Silva, Jose Ramon Jimenez, Jose Maria Fernandez-Rodriguez, Jorge de Brito
Summary: This study investigated the effect of replacing fly ash with reactive magnesium oxide (MgO) in alkali-activated fly ash mortars under two different environments. The results showed that the substitution of fly ash with MgO led to a decline in compressive and flexural strength, ultrasonic pulse velocity, and dynamic Young's modulus. However, CO2 curing improved the physicomechanical properties of the samples.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Green & Sustainable Science & Technology
Siyu Han, Kailun Chen, Fanzhi Meng, Yuchen Gao, Jinglin Li, Li Lin, Weikai Qin, Jianguo Jiang
Summary: This study presents a novel pH-controlled sulfuric acid washing method for municipal solid waste incineration fly ash (FA) to enhance heavy metal stabilization and enable the co-recycling of FA and waste sulfuric acid. The leaching rate of heavy metals was significantly reduced by controlling the pH during sulfuric acid washing, and the use of sulfuric acid washed FA (SFA) in lightweight aggregate production improved heavy metal stabilization. XPS analysis further investigated the transformation of heavy metals into stable states during washing and sintering. This study offers insights into the mechanism of heavy metal stabilization and provides an environmentally sustainable solution for FA treatment.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Environmental Sciences
B. Bouzar, Y. Mamindy-Pajany
Summary: The study evaluated the potential of biomass bottom ash as reactive filters for phosphorus removal. The characteristics of the biomass bottom ash, including origin, type, particle size, chemical composition, etc., were found to influence the phosphorus removal performance. The main mechanism of phosphorus removal was determined to be the precipitation of Ca-P. Additionally, the study revealed that wastewater treatment plants serve as an important source of Ca2+ ions, promoting the precipitation of hydroxyapatite and enhancing phosphorus removal efficiency.
INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY
(2023)
Article
Environmental Sciences
B. Bouzar, Y. Mamindy-Pajany
Summary: The feasibility of physico-chemical stabilization of Cr, Mo, Pb, Se, Zn, and Sb from biomass fly ash and shooting range soil using flash metakaolins in geopolymerization processes was investigated. The results showed that the geopolymerization/carbonation stabilization processes were effective in trapping these elements over a wide pH range. Additionally, the composition of the metakaolin significantly influenced the efficiency of the stabilization process.
INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY
(2023)
Article
Environmental Sciences
Bader Bouzar, Yannick Mamindy-Pajany, Charlotte Hurel
Summary: This investigation presents a new valorization route of fly ash, based on the synthesis of layered double hydroxide (LDH) used as efficient and cost-effective adsorbent for the stabilization of contaminants in sediments.
WASTE AND BIOMASS VALORIZATION
(2023)
Article
Chemistry, Multidisciplinary
Bader Bouzar, Mahfoud Benzerzour, Nor-Edine Abriak
Summary: This study presents a new approach to minimize waste by using hydroxyapatite as an adsorbent for stabilizing fluorides in soil. The synthesized hydroxyapatites showed promising results in reducing fluoride concentrations below the threshold level. Additionally, the sequential extraction results confirmed the formation of stable and insoluble fluorapatite.
ARABIAN JOURNAL OF CHEMISTRY
(2023)
Article
Green & Sustainable Science & Technology
Zeinab Mkahal, Walid Maherzi, Yannick Mamindy-Pajany, Bader Bouzar, Nor-Edine Abriak
Summary: This study focuses on the recovery and utilization of waste paper fly ash as the main component of an eco-binder. The results show that the raw fly ash contributes to compressive strength development, while grinding improves strength, fineness, and stability. Carbonation treatment delays the setting process and enhances stability, as well as stabilizes barium and reduces its leaching potential.
SUSTAINABLE MATERIALS AND TECHNOLOGIES
(2023)
Article
Engineering, Chemical
Ri Zhang, Shasha Zhang, Mengyan Ding
Summary: A thin liquid film method is proposed to evaluate sand erosion in annular flow. This method considers the direct interaction between the liquid film and gas core, as well as the entrainment and deposition of droplets. The erosion rate is calculated by considering the effects of liquid entrainment and particle velocity decay. The method is fully verified by comparing with experimental data.
Article
Engineering, Chemical
Yu Suo, Xianheng Su, Wenyuan He, Xiaofei Fu, Zhejun Pan
Summary: This research investigates the mechanical properties of sandstone-shale composite through orthogonal experimental method and discrete element simulation. The results show that different lithologies and thickness ratios can affect the strength and fracture mode of the composite rock samples.
Article
Engineering, Chemical
Maurizio Troiano, Andrea El Hassanin, Roberto Solimene, Alessia Teresa Silvestri, Fabrizio Scala, Antonino Squillace, Piero Salatino
Summary: This study investigates the potential of Fluidized Bed Finishing (FBF) for square flat AlSi10Mg specimens manufactured via Laser-Powder Bed Fusion (L-PBF) additive manufacturing technology. The results show that good finishing can be achieved using rotation-assisted tests, with a maximum reduction of surface roughness by 67%. Steel particles are found to be the most effective bed material.
Review
Engineering, Chemical
Ningbo Song, Wanzhong Yin, Jin Yao
Summary: Seawater's dissolved salts and minerals have various effects on the flotation process, including influencing the characteristics and behavior of flotation factors, as well as affecting the surface of sulfide minerals. In most cases, seawater has adverse effects on the flotation of sulfide minerals, but these effects can be mitigated by adjusting the reagents.
Article
Engineering, Chemical
Kaiqiao Wu, Shuxian Jiang, Victor Francia, Marc-Olivier Coppens
Summary: In rectangular and cylindrical annular fluidized beds, pulsating gas flow can create regular bubble patterns, overcoming challenges seen in conventional units. This study provides new opportunities for modularization of fluidized bed operations.
Article
Engineering, Chemical
Shuo Li, Huili Zhang, Jan Baeyens, Miao Yang, Zehao Li, Yimin Deng
Summary: The paper assesses the behavior of cohesive Geldart C-type particles when fluidized by air with the aid of vibration. It determines that mechanical vibration is a simple and effective method to improve the fluidity of cohesive particles during fluidization.
Article
Engineering, Chemical
Zhenfei Feng, Qingyuan Zhang, Shanpan Liang, Zhenzhou Li, Fangwen Guo, Jinxin Zhang, Ding Yuan
Summary: A new micro/mini-channel heat sink (MCHS) with a combined structure of longitudinal and transverse vortex generators is designed, using Al2O3 nanofluid as the working medium. The study explores the effects of transverse vortex generator shape and longitudinal vortex generator angle on the hydraulic and thermal characteristics, comprehensive performance, entropy generation, and exergy efficiency. The results show that the triangular transverse vortex generator improves the comprehensive performance and exergy efficiency. Combined with the longitudinal vortex generator, the MCHS achieves the best comprehensive performance, entropy generation, and exergy efficiency when the Reynolds number is 742.
Article
Engineering, Chemical
Kostas Giannis, Christoph Thon, Guoqing Yang, Arno Kwade, Carsten Schilde
Summary: This study presents a 3D convolutional neural network (3D-CNN) methodology for generating realistic 3D models of particles. The method trains on 2D projections of particle images to predict their 3D shapes, and evaluates the accuracy of the predictions using Fourier shape descriptors (FSDs). This methodology has wide applications in particle shape analysis.
Article
Engineering, Chemical
Zheng-qing Zhou, Lu-jia Chai, Yu-long Zhang, Ya-bin Wang, Ze-chen Du, Tian-yi Wang, Yu-zhe Liu
Summary: The dynamic oxidation and shell-breaking processes of aluminum nanoparticles (ANPs) during heating were studied using in situ transmission electron microscopy. The results revealed that the changes in shell thickness can be divided into three stages, and the active aluminum content of ANP decreased before shell-breaking.
Article
Engineering, Chemical
Fulei Chen, Huaqing Ma, Zihan Liu, Lianyong Zhou, Yongzhi Zhao
Summary: A particle breakage model based on the particle replacement scheme, using the polyhedral model to describe particles, is proposed in this work to accurately describe the breakage of a large number of particles. Additionally, a fast-cutting algorithm is proposed to reproduce the size distribution of progeny particles determined by the breakage model. The validation and simulation results show satisfactory accuracy, efficiency, and stability of the algorithm.
Review
Engineering, Chemical
Matteo Errigo, Christopher Windows-Yule, Massimiliano Materazzi, Dominik Werner, Paola Lettieri
Summary: Gas-solid fluidized-bed systems have advantages in terms of chemical reaction efficiency and temperature control, making them widely used in industrial applications. However, the design, scale-up, and optimization of these complex units are limited by the lack of deep physical understanding. Non-invasive and non-intrusive diagnostic techniques provide a way for researchers to study these systems without affecting the flow field or directly contacting the medium under study.
Article
Engineering, Chemical
Saeed Fateh, Mohammad Behshad Shafii, Mohammad Najafi, Cyrus Aghanajafi
Summary: Applying a magnetic field to ferrofluids alters their flow characteristics and enhances heat transfer. Through visualization and quantitative investigation, it is found that the magnetic field influences the flow patterns and velocity profiles, improving fluid mixing and vorticity magnitude.
Article
Engineering, Chemical
Lei Gao, Bingbing Wei, Xiaochuan Hu, Zaifeng Yao, Yiwen Fang, Xuejian Gao
Summary: In this study, a numerical model of sand triaxial test was established using discrete element software PFC3D, and an indoor triaxial test was conducted to calibrate the numerical model. The influence of microscopic parameters on the macroscopic mechanical response of sand was analyzed. The results showed that the friction coefficient had the greatest impact on the peak strength and residual strength of the sand's stress-strain curve, and it was positively correlated. The normal tangential stiffness ratio was negatively correlated, while the porosity and boundary flexibility stiffness had minimal influence on it.
Article
Engineering, Chemical
Xuan Liu, Jie Gong, Kai Jiang, Xiaojuan Lai, Yu Tian, Kang Zhang
Summary: This study aimed to improve the performance of lignite coal water slurries (CWSs) by synthesizing a series of three-arm amphiphilic block copolymers. By controlling the relative molecular weight, hydrophilic/hydrophobic ratio, and ionic group content, the apparent viscosity of CWSs was significantly reduced and the static stability was improved. Thermogravimetric testing and XPS analysis were conducted to reveal the mechanism behind the improved performance.
Article
Engineering, Chemical
Lanka Dinushke Weerasiri, Daniel Fabijanic, Subrat Das
Summary: Fluidization at low pressure offers significant benefits for the fine chemical industry. This study investigates the behavior of bubbles and bed expansion under low pressure conditions. It is found that lower pressure leads to larger bubbles, increased bubble quantity, and higher aspect ratio. The predictability is affected by the inhomogeneous fluidization, but low pressure fluidization can generate similar bubble sizes with lower fluidizing mass compared to atmospheric pressure.