Extraction and Characterization of Silica Powders from Natural Waste for Environmental Remediation

2018 ◽  
Vol 934 ◽  
pp. 147-153
Author(s):  
Areeya Ti-Iatyor ◽  
Thawatchai Kongkue ◽  
Tawat Chanadee
Keyword(s):  
Environmental Remediation ◽  
Sodium Hydroxide Solution ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Waste Materials ◽  
Ft Ir ◽  
Groundnut Shell ◽  
Banana Leaves ◽  
Groundnut Shell Ash

The present work describes the preparation and characterization of silica powder from the natural waste materials stink bean pod, Barbados pride pod, banana leaves, coconut shell, sugar palm shell and groundnut shell. Ash was produced by incineration of the natural wastes at 650 °C for 1, 3 and 5 h in atmospheric air. Silica was then extracted from the natural waste ash using 1 M sodium hydroxide solution to produce a sodium silicate solution from which silica was precipitated by adding 5 M hydrochloric acid solution. The results showed that the low content of residual carbon from the natural waste was incinerated at the optimal condition of 650°C for 5 h. FT-IR indicated that the as-prepared silica had Si-O-Si and Si-OH functional groups consistent with the XRF analysis, which detected SiO2 content between 73.76 and 95.72 wt%. In analysis of XRD and SEM, the as-prepared silica exhibited an amorphous, irregular shape and particle sizes in a range from 1 to 2 μm. The results obtained by the reported method proved that natural waste materials can be used for the production of valuable silica.

scholarly journals Synthesis and Characterization of Industrial Casting Sand Based Silica Aerogel

2021 ◽  
Vol 9 (12) ◽  
pp. 1254-1258
Author(s):  
Tuba Arkan
Keyword(s):  
Silica Aerogel ◽  
Ph Value ◽  
Sol Gel ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Chemical Components ◽  
Ft Ir ◽  
Casting Sand ◽  
Xrf Analyses

Abstract: In this study, a commercial foundry sand (Seydisehir Eti Aluminium Co. Inc.) was provided as the starting material. Using this supplied casting sand, silica aerogel production was carried out by sol-gel method. Starting materials chemical components were determined by doing XRD and XRF analyses to starting industrial casting sand respectively. After analysing studies, sodium silicate solution was produced from commercial casting sand. During silica aerogel synthesize, 5 different pH degree was investigated including 2-4-6-8 and 9. Silica aerogel modification (Super hydrophobic) was made by choosing the optimum pH value. Afer then, on the synthesized experiment sample, FT-IR, BET, SEM and contact angle characterization studies were realised respectively. As a result of preliminary experiments done with different pH experiments, sample with the lowest density was determined as pH 8 value. Keywords: Casting sand, Sol-gel, Silica aerogel

scholarly journals Possible Recycling of End-of-Life Dolomite Refractories by the Production of Geopolymer-Based Composites: Experimental Investigation

2021 ◽  
Author(s):  
E. Furlani ◽  
A. Rondinella ◽  
E. Aneggi ◽  
S. Maschio
Keyword(s):  
Experimental Investigation ◽  
End Of Life ◽  
Sodium Hydroxide Solution ◽  
Sodium Silicate Solution ◽  
Maximum Size ◽  
Silicate Solution ◽  
Refractory Powder ◽  
Dolomite Refractory ◽  
Higher Temperature

AbstractProduction and characterization of geopolymers prepared by mixing metakaolin, end-of-life dolomite refractories, sodium silicate solution, and sodium hydroxide solution have been performed. The as-received refractory was crumbled in order to obtain products having, respectively, 250 μm, 1 mm, and 2.5 mm maximum particles size. Each batch of powder was added in different proportions to a blank geopolymeric matrix. It has been observed that the addition of waste refractory reduces workability of the reference refractory-free slurry. After hardening, only the set of samples prepared with powders with maximum size of 250 μm maintain integrity while the others resulted affected by the presence of fractures caused by volumetric instabilities; samples with composition R100 showed the highest compressive strength, whereas higher refractory addition lowers strength. Specific surface area appears independent by materials composition; conversely pore volume slightly increases with the addition of dolomite refractory powder. During the thermodilatometric tests all compositions display a shrinkage of about 0.1% between 170 and 400 °C; however, sintering starts at higher temperature (above 600 °C) and samples melt in the range between 650 and 750 °C as a function of their composition, thus showing that the resulting materials loose refractoriness with respect to both the reference geopolymer and the dolomite refractory. Graphical Abstract

A Study on a Green Route to Preparation of Silica Powders with Rice Husk Ash

2014 ◽  
Vol 1010-1012 ◽  
pp. 1015-1019
Author(s):  
Ze Xin Yang ◽  
Lin Dong ◽  
Meng Wang ◽  
Huan Li
Keyword(s):  
Sodium Bicarbonate ◽  
Sodium Silicate ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Sodium Hydroxide Solution ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Raw Material ◽  
Transmission Electron ◽  
Thermal Analyzer

The main purpose of this article is to develop an environmentally friendly and economically effective process to produce silica from rice husk ash. Sodium silicate solution was prepared by the reaction of rice husk ash and sodium hydroxide solution, and then the sodium silicate solution was used as the raw material for the preparation of silica with sodium bicarbonate. During the reaction, the by-product can be passed into CO2 to prepare sodium bicarbonate what can be reutilized. Experimental route achieved resource recycling and environment-friendly, low energy consumption, zero emissions and so on. Meanwhile the microstructures of the silica powders were characterized by Transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) and Thermo gravimetric/Differential thermal analyzer (TG-DTA).The purity of silicon was up to 99.43% and the particle size was 200-300nm.

scholarly journals GREEN SYNTHESIS AND SPECTROSCOPIC CHARACTERIZATION OF IRON (III) COMPLEX OF UREA FROM HUMAN URINE AND IRON RUST

2020 ◽  
Vol 45 (5) ◽  
Author(s):  
V.O. Uduah ◽  
J.J. Gongden ◽  
M.L. Kagoro ◽  
K.K. Gurumyen ◽  
Y.N. Lohdip ◽  
...  
Keyword(s):  
Human Urine ◽  
Synthesis Method ◽  
Reaction Medium ◽  
Spectroscopic Characterization ◽  
Waste Materials ◽  
Spectroscopic Techniques ◽  
Distilled Water ◽  
Oxide Composition ◽  
Ft Ir

This work presents a dry synthesis of Iron (III) complex with urea isolated from human urine and Fe (III) obtained from iron rust particles. Iron (III), PI (Purified iron rust), was isolated from iron rust in 10% hydrochloric acid, HCl and distilled water respectively. The complex was synthesized via dry-synthesis method using the melted urea as reaction medium. The isolated Fe (III) was characterized by elemental analysis which was done using XRF Cu-Zn method. The complex was prepared in a 1:4 metal to ligand (M-L) ratio. The stoichiometry of reaction indicate a 1:3 ratio of M-L (Fe-U). The complex was characterized by FT-IR, UV-vis, XRF and XRD spectroscopic techniques. The Fe (III) isolate and Fe-U complex shows percentage yields of 35.7% and ~92% respectively. The elemental and oxide composition of Fe and Fe2O3 (i.e., PI) were 40.387% and 57.753% respectively. The results obtained from the characterization of the iron-urea complex, IUC, indicate FT-IR result as symmetric and asymmetric frequencies with peaks of a combination band of Vs (NH) and Vas (NH), C=O and V (C-N) all stretched, XRD showed the crystal to be amorphous. The elemental and oxide composition of the Fe and Fe2O3 in IUC were 40.007 and 44.201 respectively. The results obtained revealed that useful complexes can be synthesized easily from waste materials, such as urine and iron rust particles, which complement Green chemistry.

Effect of Partial Replacement of Fly Ash by Metakaolin on Strength Development of Fly Ash Based Geopolymer Mortar

2017 ◽  
Vol 744 ◽  
pp. 131-135 ◽  
Author(s):  
Muhammad Zahid ◽  
Nasir Shafiq ◽  
Mohd Fadhil Nuruddin ◽  
Ehsan Nikbakht ◽  
Asif Jalal
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Sodium Hydroxide Solution ◽  
Base Material ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Partial Replacement ◽  
Strength Development ◽  
Class C ◽  
Class F

This article aims to investigate the compressive strength variation by the addition of metakaolin as a substitute of fly ash in the fly ash based geopolymer mortar. Five, ten and fifteen percent by weight of fly ash was replaced by highly reactive metakaolin. Two type of fly ashes namely, ASTM class F and ASTM class C were used as a base material for the synthesis of geopolymer mortar. Eight molar sodium hydroxide solution mixed with sodium silicate solution was used as alkaline activator. For optimum geopolymerization, mortar was cured at sixty degree Celsius for twenty four hours duration. Results show different behavior of metakaolin replacement on compressive strength for two different types of fly ash based geopolymer mortar. Improvement in compressive strength was seen by addition of metakaolin in ASTM class F fly ash based geopolymer. On the other hand compressive strength was decreased abruptly in fly ash class C based geopolymer up to certain replacement level.

scholarly journals Characterization of magnetic biochar amended with silicon dioxide prepared at high temperature calcination

2016 ◽  
Vol 34 (3) ◽  
pp. 597-604 ◽  
Author(s):  
Shams Ali Baig ◽  
Zimo Lou ◽  
Malik T. Hayat ◽  
Ruiqi Fu ◽  
Yu Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Silicon Dioxide ◽  
Environmental Remediation ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Magnetic Biochar ◽  
Ft Ir ◽  
High Temperature Calcination

AbstractCalcination is considered to increase the hardness of composite material and prevent its breakage for the effective applications in environmental remediation. In this study, magnetic biochar amended with silicon dioxide was calcined at high temperature under nitrogen environment and characterized using various techniques. X-ray diffraction (XRD) analysis revealed elimination of Fe3O4 peaks under nitrogen calcination and formation of Fe3Si and iron as major constituents of magnetic biochar-SiO2 composite, which demonstrated its superparamagnetic behavior (>80 A2·kg−1) comparable to magnetic biochar. Thermogravimetric analysis (TGA) revealed that both calcined samples generated higher residual mass (>96 %) and demonstrated better thermal stability. The presence of various bands in Fourier transform infrared spectroscopy (FT-IR) was more obvious and the elimination of H–O–H bonding was observed at high temperature calcination. In addition, scanning electron microscopy (SEM) images revealed certain morphological variation among the samples and the presence of more prominent internal and external pores, which then judged the surface area and pore volume of samples. Findings from this study suggests that the selective calcination process could cause useful changes in the material composites and can be effectively employed in environmental remediation measures.

scholarly journals Effect of Concentration of Sodium Hydroxide and Degree of Heat Curing on Fly Ash-Based Geopolymer Mortar

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Subhash V. Patankar ◽  
Yuwaraj M. Ghugal ◽  
Sanjay S. Jamkar
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Sodium Hydroxide ◽  
Sodium Hydroxide Solution ◽  
Large Change ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Test Period ◽  
Hydroxide Solution ◽  
Increase With Increase

Geopolymer concrete/mortar is the new development in the field of building constructions in which cement is totally replaced by pozzolanic material like fly ash and activated by alkaline solution. This paper presented the effect of concentration of sodium hydroxide, temperature, and duration of oven heating on compressive strength of fly ash-based geopolymer mortar. Sodium silicate solution containing Na2O of 16.45%, SiO2 of 34.35%, and H2O of 49.20% and sodium hydroxide solution of 2.91, 5.60, 8.10, 11.01, 13.11, and 15.08. Moles concentrations were used as alkaline activators. Geopolymer mortar mixes were prepared by considering solution-to-fly ash ratio of 0.35, 0.40, and 0.45. The temperature of oven curing was maintained at 40, 60, 90, and 120°C each for a heating period of 24 hours and tested for compressive strength at the age of 3 days as test period after specified degree of heating. Test results show that the workability and compressive strength both increase with increase in concentration of sodium hydroxide solution for all solution-to-fly ash ratios. Degree of heating also plays vital role in accelerating the strength; however there is no large change in compressive strength beyond test period of three days after specified period of oven heating.

Preparation and characterization of sugarcane bagasse hemicellulosic derivatives containing quaternary ammonium groups in various media

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Ren Jun-Li ◽  
Liu Chuan-Fu ◽  
Sun Run-Cang ◽  
She Diao ◽  
Liu Jian-Chao
Keyword(s):  
Dimethyl Sulfoxide ◽  
Sodium Hydroxide ◽  
Sodium Hydroxide Solution ◽  
Aqueous Sodium Hydroxide ◽  
Molar Ratio ◽  
Aqueous Sodium ◽  
Ft Ir ◽  
Thermal Stability Of ◽  
C Nmr

AbstractTo increase the solubility and produce cationic or ampholytic polymers as beater additives in papermaking from native hemicelluloses, quaternization of hemicelluloses were performed by reacting hemicelluloses with 3-chloro-2- hydroxypropyltrimethylammonium chloride (CHMAC) and preferably with 2,3- epoxypropyltrimethylammonium chloride (ETA) in aqueous sodium hydroxide, homogenously in dimethyl sulfoxide (DMSO), and completely heterogeneously in ethanol/water, respectively. The extent of modification was measured by degree of substitution (DS), and its value of up to 0.55 can be controlled by adjusting the molar ratio of reagent to hydroxyl functionality in hemicelluloses and the concentration of sodium hydroxide. The characterization of hemicellulosic derivatives was performed by elemental analysis, GPC, FT-IR and 13C NMR spectroscopy as well as thermal analysis. It was found that hemicellulosic polymer was significantly degraded in aqueous sodium hydroxide solution compared with in dimethyl sulfoxide and in ethanol/water systems under the conditions given. The thermal stability of modified hemicelluloses decreased after chemical modification, corresponding to the decreasing Mw of hemicelluloses derivatives.

A Study on Relationship between Porosity and Compressive Strength for Geopolymer Paste

2013 ◽  
Vol 594-595 ◽  
pp. 1112-1116 ◽  
Author(s):  
Z.F. Farhana ◽  
H. Kamarudin ◽  
Azmi Rahmat ◽  
A.M. Mustafa Al Bakri
Keyword(s):  
Compressive Strength ◽  
Sodium Hydroxide Solution ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Pulse Velocity ◽  
Strength Test ◽  
Compressive Strength Test ◽  
Alkaline Activator ◽  
The Relationship ◽  
Geopolymer Paste

This paper presents a study on the relationship between porosity and compressive strength for geopolymer paste. In this research, geopolymer paste was made from fly ash class F based geopolymer mixed with alkaline activator; sodium hydroxide solution and sodium silicate solution. Twelve mixes were cast in 50mm x 50mm x 50mm moulds and the samples were cured for 24 hrs at 60 °C in the oven. The samples were examined after 7, 14, 28 and 90 days in terms of porosity test, pulse velocity test and compressive strength test. It was concluded that the sample at day 90 had the highest compressive strength of 56.50 N/mm2had porosity 3.77%. Thus, the sample with lowest porosity had highest pulse velocity 3303 m/s during ultrasonic testing with lowest transmission time 15.17 μs. Keywords: porosity, compression strength, geopolymer, pulse velocity

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