scholarly journals Synthesis and Characteristic of Precipitated Nano-Silica

2013 ◽  
Vol 6 (1) ◽  
pp. 917-922 ◽  
Author(s):  
Mohammad Sadeghi ◽  
Mahboubeh Dorodian ◽  
Masoumeh Rezaei
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Sulfuric Acid ◽  
Sodium Silicate ◽  
Sodium Dodecyl ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Precipitation Process ◽  
Nano Silica ◽  
Precipitated Silica

The reaction of precipitation of amorphous silicon dioxide from aqueous solution of sodium silicate and sulfuric acid has been studied. The factors affecting the precipitation process of the sodium silicate solution such as sodium silicate concentration and addition of anionic surfactant (sodium dodecyl sulfate, SDS) on particle size, size distribution and degree of agglomeration of the precipitated silica were examined. The precipitation of silica from the produced sodium silicate solution was carried out using sulfuric acid at pH 7. Scaning electron microscope (SEM), transmission electron microscope (TEM) and Dynamic light scattering (DLS) have been used for characterization of the produced nano-silica. The surface area of silica was tested by oil absorption method according to ASTM standard. Results showed that the particle size of the precipitated silica gel was decreased with increasing Na2SiO3 and SDS concentrations and Particle size of about 44nm can be achieved at 20% Na2SiO3 and 200ppm SDS. But with decreasing particle size, degree of agglomeration also increased.

scholarly journals Silica extraction from bauxite reaction residue and synthesis water glass

2021 ◽  
Vol 10 (1) ◽  
pp. 268-283
Author(s):  
Yunlong Zhao ◽  
Yajie Zheng ◽  
Hanbing He ◽  
Zhaoming Sun ◽  
An Li
Keyword(s):  
Sodium Silicate ◽  
Water Glass ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Hydrated Calcium Silicate ◽  
Precipitated Silica ◽  
Alumina Gel ◽  
Silica Alumina ◽  
Element Removal ◽  
Hydrated Calcium

Abstract Bauxite reaction residue (BRR) produced from the poly-aluminum chloride (PAC) coagulant industry is a solid acidic waste that is harmful to environment. A low temperature synthesis route to convert the waste into water glass was reported. Silica dissolution process was systematically studied, including the thermodynamic analysis and the influence of calcium and aluminum on the leaching of amorphous silica. Simulation studies have shown that calcium and aluminum combine with silicon to form hydrated calcium silicate, silica–alumina gel, and zeolite, respectively, thereby hindering the leaching of silica. Maximizing the removal of calcium, aluminum, and chlorine can effectively improve the leaching of silicon in the subsequent process, and corresponding element removal rates are 42.81%, 44.15%, and 96.94%, respectively. The removed material is not randomly discarded and is reused to prepare PAC. The silica extraction rate reached 81.45% under optimal conditions (NaOH; 3 mol L−1, L S−1; 5/1, 75°C, 2 h), and sodium silicate modulus (nSiO2:nNa2O) is 1.11. The results indicated that a large amount of silica was existed in amorphous form. Precipitated silica was obtained by acidifying sodium silicate solution at optimal pH 7.0. Moreover, sodium silicate (1.11) further synthesizes sodium silicate (modulus 3.27) by adding precipitated silica at 75°C.

Effect of the gelation on the properties of precipitated silica powder produced by acidizing sodium silicate solution at the pilot scale

2012 ◽  
Vol 209 ◽  
pp. 531-536 ◽  
Author(s):  
Dang Viet Quang ◽  
Jong-Kil Kim ◽  
Jin-Koo Park ◽  
Seok-Hoon Park ◽  
Gideon Elineema ◽  
...  
Keyword(s):  
Sodium Silicate ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Pilot Scale ◽  
Silica Powder ◽  
Precipitated Silica

Precipitated Silica from Sodium Silicate by CO2 on Fixed Bed Column

2019 ◽  
Vol 966 ◽  
pp. 14-18
Author(s):  
Retno Dewati ◽  
Suprihatin ◽  
Ketut Sumada ◽  
Srie Muljani
Keyword(s):  
Sodium Silicate ◽  
Fixed Bed ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Ph Control ◽  
Fixed Bed Column ◽  
Precipitated Silica ◽  
Silica Concentration ◽  
Control Apparatus

The precipitated silica prepared by reaction of sodium silicate and gas CO2 on fixed bed column have been production successfully. In this study, silica from bagasse was extraction by sodium hydroxide 2N solution to produce sodium silicate solution. The sodium silicate solution was dilute by demineralize water to produce some concentration in the range of 0.33-0.98 %SiO2. Fixed bed column has a diameter of 7.5 cm with a height of 50 cm and a pH control apparatus. CO2 gas and sodium silicate liquid are both flowed from under of the column with a specified flow rate. The precipitate process was carried out on a fixed bed column with high of bed in the range of 10-30 cm. The effect of silica concentration and the high of the bed on the characterize of the precipitated silica product have been studied. The precipitated silica product characterized by XRF, XRD, SEM-EDX and BET. The quality of precipitated silica produced in the range concentration of 95-98 w% SiO2, surface area (BET) in the range of 46.1 – 58.8 m2/g.

Synthesis of Nanosized NaY Molecular Sieve under Dynamic Hydrothermal Crystallization

2014 ◽  
Vol 609-610 ◽  
pp. 288-297
Author(s):  
Ying Chen ◽  
Peng Liu ◽  
Zhi Wu Yu ◽  
Juan Tan
Keyword(s):  
Grain Size ◽  
Electron Microscope ◽  
Sodium Silicate ◽  
Molecular Sieves ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Mixed Solution ◽  
Relative Crystallinity ◽  
Synthesis Conditions ◽  
Transmission Electron

Nanosized NaY molecular sieves with high crystallinity was synthesized using sodium silicate solution (industrial water glass) without the presence of additive via dynamic hydrothermal method. The influences of aging time of the seed-gel, the temperature and route of gelation, and the alkalinity of the feed-stock gel on the grain size, relative crystallinity and framework SiO2/Al2O3 ratios of NaY nanoparticles were investigated by XRD(X-ray diffraction, XRD), SEM(Scanning electron microscope, SEM) and TEM(Transmission electron microscope, TEM). The results shown that the grain size could be effectively controlled by adding seed-gel of aging at 20°C for 4 days, and adopting the gelation route of putting sodium silicate solution into NaAlO2 and NaOH mixed solution. The grain size and framework SiO2/Al2O3 ratios decreased with reducing the alkalinity of synthetic system. The nanoNaY products with the grain size at a range of 82-105 nm and the framework SiO2/Al2O3 ratios at 3.9-4.0 could be synthesized by optimizing the synthesis conditions.

Synthesis of Nanosized Silica Powder by Ultrasonic Process

2006 ◽  
Vol 11-12 ◽  
pp. 669-672
Author(s):  
Sang Geun Lee ◽  
Hyung Sup Kim ◽  
Seong Soo Park ◽  
Byung Young Moon ◽  
Beom Soo Kang ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Sodium Silicate ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Silica Powder ◽  
Emulsion Method ◽  
Ultrasonic Process ◽  
Nanosized Silica

Nanosized silica powders were synthesized via w/o emulsion method using sodium silicate as SiO2 source under ultrasonic process. The powders were prepared under conventional process and ultrasonic process using the same reactants at ambient temperature for 1h varying the concentration of Na2SiO3 solution while fixing the concentration of surfactant in cyclohexane. The particle size of the silica powder decreased with decreasing the concentration of sodium silicate solution under both conditions, with and without ultrasounds. However, the particle size and size distribution of the silica powder with ultrasounds were smaller and narrower than those without ultrasounds, establishing that ultrasound treatments decrease the particle size and become narrow in particle size distribution.

scholarly journals Printability and Setting Time of CSA Cement with Na2SiO3 and Gypsum for Binder Jetting 3D Printing

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2811
Author(s):  
Okpin Na ◽  
Kangmin Kim ◽  
Hyunjoo Lee ◽  
Hyunseung Lee
Keyword(s):  
3D Printing ◽  
Sodium Silicate ◽  
Setting Time ◽  
Sodium Silicate Solution ◽  
Preliminary Test ◽  
Silicate Solution ◽  
Calcium Sulfoaluminate Cement ◽  
Calcium Sulfoaluminate ◽  
Parametric Studies ◽  
Binder Jetting

The purpose of this study is to optimize the composition of CSA (calcium sulfoaluminate) cement with sodium silicate (Na2SiO3) and gypsum for binder jetting 3D printing. The preliminary test was carried out with an applicator to decide the proper thickness of one layer before using the 3D printer. A liquid binder was then selected to maintain the shape of the particles. Based on the results, the optimal mixture of dry materials and a liquid activator was derived through various parametric studies. For dry materials, the optimum composition of CSA cement, gypsum, and sand was suggested, and the liquid activator made with sodium silicate solution and VMA (viscosity modified agent) were selected. The setting time with gypsum and sodium silicate was controlled within 30 s. In case of the delayed setting time and the rapid setting mixture, the jetting line was printed thicker or thinner and the accuracy of the printout was degraded. In order to adjust the viscosity of the liquid activator, 10% of the VMA was used in 35% of sodium silicate solution and the viscosity of 200–400 cP was suitable to be sprayed from the nozzle. With this optimal mixture, a prototype of atypical decorative wall was printed, and the compressive strength was measured at about 7 MPa.

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.

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