scholarly journals Review of the Reuse Possibilities Concerning Ash Residues from Thermal Process in a Medium-Sized Urban System in Northern Italy

2020 ◽  
Vol 12 (10) ◽  
pp. 4193 ◽  
Author(s):  
Ahmad Assi ◽  
Fabjola Bilo ◽  
Alessandra Zanoletti ◽  
Jessica Ponti ◽  
Andrea Valsesia ◽  
...  

This review paper reports a detailed characterization of some combustion or incineration residues and by-products produced in a medium-sized city in Northern Italy. The municipal solid waste incineration (MSWI) generates fly ash, which is a toxic waste. Coal fly ash (CFA) and flue gas desulfurization (FGD) derive from the thermoelectric coal plant located in the same city. Along with these ashes, silica fume and rice husk ash are also considered for the stabilization of fly ash based on their amorphous silica content with the aim to convert them into an inert material. The characterization of all the investigated ashes was performed using different techniques: X-ray diffraction, total reflection X-ray fluorescence, scanning electron microscopy, and transmission electron microscopy. The aim of this work is to describe the reuse possibilities that were proposed for these ashes, which were determined also on the basis of their structural properties. Several possible applications of the investigated ashes are proposed, and the most suitable reuse of stabilized fly ash samples seems to be the production of sustainable plastic composites. This paper shows that the reuse of the by-product materials can allow natural resources to be preserved following the principles of a circular economy.

1987 ◽  
Vol 113 ◽  
Author(s):  
G. J. McCarthy ◽  
D. M. Johansen ◽  
A. Thedchanamoorthy ◽  
S. J. Steinwand ◽  
K. D. Swanson

ABSTRACTX-ray powder diffraction has been used to determine the crystalline phase mineralogy in samples of fly ash from each of the lignite mining areas of North America. The characteristic phases of North Dakota lignite fly ashes were periclase, lime, merwinite and the sulfate phases anhydrite, thenardite and a sodalite-structure phase. Mullite was absent in these low-Al2O3 ashes. Montana lignite ash mineralogy had characteristics of ND lignite and MT subbituminous coal fly ashes; mullite and C3A were present and the alkali sulfates were absent. Texas and Louisiana lignite fly ashes had the characteristic mineralogy of bituminous coal fly ash: quartz, mullite, ferrite-spinel (magnetite) and minor hematite. Even though their analytical CaO contents were 7–14%, all but one lacked crystalline CaO-containing phases. Lignite fly ashes from Saskatchewan were generally the least crystalline of those studied and had a mineralogy consisting of quartz, mullite, ferrite spinel and periclase. Quantitative XRD data were obtained. The position of the diffuse scattering maximum in the x-ray diffractograms was indicative of the glass composition of the lignite fly ash.


1989 ◽  
Vol 33 ◽  
pp. 673-678
Author(s):  
Sz. Török ◽  
Sz. Sándor ◽  
H. Rausch

The assessment of the potential environmental and toxicological effects of particulate material emitted to the atmosphere requires detailed physical and chemical characterization of the particles. One of the most widely studied types of pollutant particles is coal fly ash as a byproduct of coal combustion. These particles are inhomogeneous, highly variable, span a broad range of sizes and have diverse morphologies.It has been shown that numerous toxic trace elements tend to increase in bulk concentrations with decreasing particle size (1).


2016 ◽  
Vol 1813 ◽  
Author(s):  
M. Rendón Belmonte ◽  
A. Palomo Sánchez ◽  
A. Fernández Jiménez ◽  
A. Torres Acosta ◽  
M. Martínez Madrid ◽  
...  

ABSTRACTThis paper focus on evaluating the ability to use Mexican fly ash (FA) and copper slag (CS) to produce alkali cements (0% OPC) or hybrid cements (20% OPC + 80% fly ash). The alkali activators used were two: 8 M NaOH solution for alkali cements and NaCl with sodium silicate for hybrid cement (HYC). Results of mechanical testing and characterization of the reaction products formed after 2 and 28 days are presented and discussed. Mechanical strength in some cases exceeded 20 MPa, at 2 days curing. The chemical characterization techniques used were X-Ray Diffraction (XRD) and scanning electron microscopy (SEM).


Author(s):  
Amalia Ekaputri Hidayat ◽  
Setyo Sarwanto Moersidik ◽  
Sandyanto Adityosulindro

Coal burning process in steam powered electric generator plants functioned to generate electricity energy. This process produce kinds of waste, such as solid waste, waste water, and emission. One of the solid waste produced in this process is fly ash. Fly ash is categorized as hazardous waste, it also can buildup in the landfill because of its massive production. However, fly ash has the potential as a raw material to produce synthetic zeolite because it contains metal oxide which is quite high. In this study, class F coal fly ash was synthesized by combining hydrothermal and fusion method. Synthesized fly ash and zeolite are characterized so that the chemical composition can be analyzed by X-ray Fluorescence; the mineralogy analyzed by X-ray Diffraction; the surface morphology analyzed by Scanning Electron Microscopy; and the particle size analyzed by Particle Size Analyzer. The synthesis of zeolite from coal fly ash in this study result hydroxy-sodalite zeolite type. In addition, this synthesis process increases the surface area of the previous fly ash. From the characteristics of zeolite from this synthesis it can be conclude that this zeolite can be approved as an adsorbent for the removal of liquid or gas pollutants in environmental technology applications with further research. ABSTRAKProses yang terjadi pada Pembangkit Listrik Tenaga Uap untuk menghasilkan energi listrik adalah melalui unit proses pembakaran batubara. Proses ini akan menghasilkan limbah padat, cair, maupun udara. Salah satu limbah padat yang dihasilkan adalah abu layang. Limbah abu layang ini dikatagorikan limbah bahan berbahaya dan beracun, serta dapat terjadinya penumpukan di tempat penimbunan akhir karena produksinya yang sangat tinggi. Namun, abu layang memiliki potensi sebagai bahan baku dalam memproduksi zeolit sintetik karena kandungan oksida logamnya yang cukup tinggi. Pada penelitian ini, abu layang batu bara kelas F disintesis dengan metode gabungan fusi-hidrotermal. Abu layang dan zeolit yang disintesis dikarakterisasi agar dapat dianalisis komposisi kimianya dengan X-ray Flourescence; mineraloginya dengan X-ray Diffraction; morfologi permukaan dengan Scanning Electron Microscopy; serta distribusi partikel dengan Particle Size Analyzer. Proses sintesis zeolit dari abu layang batubara pada penelitian ini menghasilkan zeolit jenis hidroksi sodalit. Selain itu, proses sintesis ini meningkatkan luas permukaan dari abu layang sebelumnya. Dari karakteristik zeolit hasil sintesis ini dapat disimpulkan bahwa zeolit ini dapat berpotensi sebagai adsorben untuk penyisihan polutan cair maupun gas pada aplikasi teknologi lingkungan dengan penelitian lebih lanjut.Kata kunci : abu layang; zeolit; hidroxi-sodalit; sintesis; fusi-hidrotermal


Author(s):  
J. H. Resau ◽  
N. Howell ◽  
S. H. Chang

Spinach grown in Texas developed “yellow spotting” on the peripheral portions of the leaves. The exact cause of the discoloration could not be determined as there was no evidence of viral or parasitic infestation of the plants and biochemical characterization of the plants did not indicate any significant differences between the yellow and green leaf portions of the spinach. The present study was undertaken using electron microscopy (EM) to determine if a micro-nutrient deficiency was the cause for the discoloration.Green leaf spinach was collected from the field and sent by express mail to the EM laboratory. The yellow and equivalent green portions of the leaves were isolated and dried in a Denton evaporator at 10-5 Torr for 24 hrs. The leaf specimens were then examined using a JEOL 100 CX analytical microscope. TEM specimens were prepared according to the methods of Trump et al.


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