scholarly journals X-Ray Diffraction and SEM Investigation of Solidification/ Stabilization of Nickel and Chromium Using Fly ash

2011 ◽  
Vol 8 (s1) ◽  
pp. S395-S403 ◽  
Author(s):  
Ranjana A. Patil ◽  
Sangesh P. Zodape

The main thrust of the paper is mechanism of immobilization of nickel(Ni) and chromium(Cr) metal sludge by solidification/stabilization using lime fly ash and sand (LFAS). The mineralogy of fly ash used for the study has been determined on the basis of x- ray diffraction analysis (XRD). Attempts have been made to investigate the consequences of interaction of heavy metal ion with constituents of lime fly ash sand composite on the basis of XRD studies and scanning electron microscopy (SEM, except chromium).

2021 ◽  
Vol 325 ◽  
pp. 181-187
Author(s):  
Martin Nguyen ◽  
Radomír Sokolář

This article examines the influence of fly ash on corrosion resistance of refractory forsterite-spinel ceramics by molten iron as a corrosive medium. Fly ash in comparison with alumina were used as raw materials and sources of aluminium oxide for synthesis of forsterite-spinel refractory ceramics. Raw materials were milled, mixed in different ratios into two sets of mixtures and sintered at 1550°C for 2 hours. Samples were characterized by X-ray diffraction analysis and thermal dilatometric analysis. Crucibles were then made from the fired ceramic mixtures and fired together with iron at its melting point of 1535°C for 5 hours. The corrosion resistance was evaluated by scanning electron microscopy on the transition zones between iron and ceramics. Mixtures with increased amount of spinel had higher corrosion resistance and mixtures with fly ash were comparable to mixtures with alumina in terms of corrosion resistance and refractory properties.


2017 ◽  
Vol 12 (1) ◽  
pp. 63-77 ◽  
Author(s):  
Siriporn Sirikingkaew ◽  
Nuta Supakata

This study presents the development of geopolymer bricks synthetized from industrial waste, including fly ash mixed with concrete residue containing aluminosilicate compound. The above two ingredients are mixed according to five ratios: 100:0, 95:5, 90:10, 85:15, and 80:20. The mixture's physico-mechanical properties, in terms of water absorption and the compressive strength of the geopolymer bricks, are investigated according to the TIS 168-2546 standard. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses are used to investigate the microstructure and the elemental and phase composition of the brick specimens. The results indicate that the combination of fly ash and concrete residue represents a suitable approach to brick production, as required by the TIS 168–2546 standard.


2010 ◽  
Vol 1265 ◽  
Author(s):  
Neil Christian Hyatt ◽  
Andreas Jenni ◽  
Martin Christopher Stennett

AbstractThe suitability of Portland cement blends for encapsulation of Cs-Ionsiv in a monolithic wasteform was investigated. No evidence of reaction or dissolution of the Cs-Ionsiv in the cementitious environment was found by scanning electron microscopy and X-ray diffraction. However, a small fraction (≤1.6 wt%) of the Cs inventory was released from the encapsulated Ionsiv during leaching experiments carried out on hydrated samples. Cs release was enhanced by exchange of K and Na present in the cementitious pore water. Cement systems lower in K and Na, such as slag based blends, showed lower Cs release than the fly ash based analogues.


Elkawnie ◽  
2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Cut Rahmawati ◽  
Sri Aprilia ◽  
Taufiq Saidi ◽  
Teuku Budi Aulia

Abstract: This study was designed to examine the mineral, microstructural, and mechanical strength properties of fly ash and its feasibility as a raw material for geopolymer cement. The study used an experimental method by examining the characteristics of fly ash by X-ray Fluorescence Spectrometer (XRF), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), hydrometer method, Scanning electron microscopy (SEM), and compressive strength testing. For creating the geopolymer cement paste, a concentration of NaOH 10M was used, with a ratio of water/solid = 0.4 and a ratio of Na2SiO3/NaOH = 1 using curring at room temperature. The results showed the geopolymer pastes have a compressive strength of 18.1 MPa and 21.5 MPa after 7 days and 28 days. The XRD results showed a decrease in the peak of 2θ at 26.54° because the amorphous part had transformed into a C-S-H solution in geopolymer cement. This finding was supported by the FTIR spectra results showing Si-O-Si bending vibration and the functional group of AlO2. It showed that Nagan Raya fly ash-based geopolymer is a potential construction material.Abstrak: Penelitian ini dirancang untuk mendapatkan sifat mineral, mikrostruktural, dan kekuatan mekanis dari fly ash serta kesesuaiannya sebagai material dasar pada semen geopolimer. Metode penelitian yang digunakan adalah metode eksperimen dengan cara  menguji karakteristik dari fly ash dengan pengujian X-ray Fluorescense Spectrometer (XRF), Fourier transform infrared (FTIR) spectoscopy, X-ray diffraction (XRD), hydrometer method, Scanning electron microscopy (SEM) dan kuat tekan.  Untuk pembuatan pasta semen geopolimer digunakan konsentrasi NaOH 10 M, rasio water/solid 0,4 dan rasio Na2SiO3/NaOH = 1 dengan perawatan pada suhu kamar. Hasil menunjukkan setelah 7 hari pasta geopolimer memiliki kuat tekan 18,1 MPa dan 21,5 MPa pada 28 hari. Hasil XRD menunjukkan adanya penurunan puncak 2θ pada 26,54° ini disebabkan karena bagian amorf dari fly ash telah menjadi larutan C-S-H pada semen geopolimer. Hasil ini diperkuat dengan analisis FTIR spectra yang menunjukkan adanya Si-O-Si bending vibration dan gugus fungsi dari AlO2. Hasil menunjukkan fly ash dari Nagan Raya potensial sebagai bahan material konstruksi berbasis geopolimer.


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).


2020 ◽  
Vol 16 (2) ◽  
pp. 171
Author(s):  
Wahyuni Wahyuni ◽  
Subaer Subaer ◽  
Nurhayati Nurhayati

Telah dilakukan penelitian tentang geopolimer berbasis fly ash dengan penambahan abu sekam padi. Penelitian ini bertujuan untuk mengetahui struktur dan sifat mekanik geopolimer berbasis fly ash dengan penambahan abu sekam padi. Geopolimer berbasis fly ash dibuat dengan penambahan abu sekam padi 0%, 20% dan 40% menggunakan metode aktivasi alkali dan dipanaskan pada suhu 70℃ selama 2 jam. Struktur mikro dari sampel  diketahui dengan menggunakan teknik X-Ray Diffraction (XRD) dan menggunakan Scanning Electron Microscopy (SEM). Gugus fungsi dari sampel diperoleh berdasarkan pengujian Fourier Transform Infra Red (FTIR). Sifat mekanik seperti Kuat tekan dari sampel diuji menggunakan Testing Mechine. Massa jenis, porositas dan kuat lentur dilakukan pengukuran terhadap sampel. Hasil penelitian menunjukkan diperoleh fase trydimate yang tertinggi pada sampel Geo FA+ASP (60+40)%. Hasil karakterisasi Scanning Elektron Microscopy (SEM) menunjukkan material penyusun sampel telah berikatan dengan baik walaupun sebagian kecil pertikel fly ash dan abu sekam padi masih terlihat dengan jelas. Gugus fungsi pembentuk geopolimer diperoleh pada stretching Si-O-Si dengan nilai gelombang antara 478-461cm-1 dan 791-781cm-1. Massa jenis tertinggi diperoleh pada sampel dengan penambahan 40% abu sekam padi dan porositas tertinggi diperoleh pada sampel tanpa penambahan abu sekam padi. Kuat tekan yang terbesar diperoleh dari sampel geopolimer berbasis fly ash tanpa penambahan abu sekam padi sedangkan kuat lentur tertingi diperoleh dari sampel geopolimer berbasis fly ash dengan  penambahan abu sekam padi sebesar 40%.


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


2011 ◽  
Vol 261-263 ◽  
pp. 816-819 ◽  
Author(s):  
Min Yang ◽  
Qing Chen Sun

Experiments were performed to investigate the properties of fly ash-calcined phosphogypsum (PG) cementitous materials with PG different thermally treated, including being calcined at 135°C, 430°C and 800°C separately. Durability of the cementitous materials was investigated by determination of mass loss of binders immersed in water for different durations and strength development subjected to various curing conditions. X-ray diffraction analysis was used to study the differences in hydration products among binders with different thermally treated PG. Morphology and microstructure of the hardened binders were investigated by scanning electron microscopy. Results suggest that the binder with PG sintered at 430°C obtains the best performance, indicating both impurities in PG and the form of gypsum influence its utilization greatly. Considering this, it can be concluded that choice of a proper thermal treatment is important.


1984 ◽  
Vol 43 ◽  
Author(s):  
R. C. Joshi ◽  
G. S. Natt ◽  
R. L. Day ◽  
D. D. Tilleman

AbstractX-ray diffraction and scanning electron microscopic analyses have been performed on the various Western Canadial fly ash fractions and on mixtures of cement and fly ash fractions. The ash mineralogy of hydrated and unhydrated fly ash samples was examined by x-ray diffraction. Results from a study of the morphology of ash particles etched in dilute hydrofluoric acid are also included. Scanning electron microscopy indicates that most of the reactive portion of the ash is on the particle surface. Also, as the fly ash particle size increases, the amount of crystalline SiO2 increases but the quantity of calcium containing compounds decreases. Crys~alline SiO2 (the majority of which is present in the +75 μm fraction) does not take part in self-hardening reactions but does appear to take part in pozzolanic reactions.


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