An Exploration of Factors Affecting the Preparation of SiO2-Coated α-Al2O3 Pearlescent Pigment

2014 ◽  
Vol 983 ◽  
pp. 26-29
Author(s):  
Nan Wu ◽  
Qing Hua Chen ◽  
Wei Ming Zhou ◽  
Mei Zhen Ke ◽  
Qing Rong Qian ◽  
...  
Keyword(s):  
Sodium Silicate ◽  
Reaction Temperature ◽  
Ph Value ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Liquid Phase Deposition ◽  
Factors Affecting ◽  
Solution Reaction ◽  
Pearlescent Pigment

The SiO2-coated α-Al2O3 pearlescent pigment was prepared by liquid phase deposition (LPD). The effects of concentration of sodium silicate solution, reaction temperature and pH value of the aluminum oxide suspending liquid were systemically studied in this paper. The obtained samples were characterized by scanning electron microscopy (SEM). The results showed that when the process parameters are the concentration of sodium silicate solution of 0.1 mol/L, the reaction temperature of 80 °C and the pH value of 9.0, the high quality of SiO2-coated α-Al2O3 pearlescent pigment could be obtained.

scholarly journals Formation of Geopolymers Using Sodium Silicate Solution and Aluminum Orthophosphate

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4202
Author(s):  
Stephan Partschefeld ◽  
Torben Wiegand ◽  
Frank Bellmann ◽  
Andrea Osburg
Keyword(s):  
Sodium Silicate ◽  
Ph Value ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amorphous Phases ◽  
Amorphous Aluminosilicate ◽  
Kinetics Of ◽  
Aluminum Orthophosphate

This paper reports the formation and structure of fast setting geopolymers activated by using three sodium silicate solutions with different modules (1.6, 2.0 and 2.4) and a berlinite-type aluminum orthophosphate. By varying the concentration of the aluminum orthophosphate, different Si/Al-ratios were established (6, 3 and 2). Reaction kinetics of binders were determined by isothermal calorimetric measurements at 20 °C. X-ray diffraction analysis as well as nuclear magnetic resonance (NMR) measurements were performed on binders to determine differences in structure by varying the alkalinity of the sodium silicate solutions and the Si/Al-ratio. The calorimetric results indicated that the higher the alkalinity of the sodium silicate solution, the higher the solubility and degree of conversion of the aluminum orthophosphate. The results of X-ray diffraction and Rietveldt analysis, as well as the NMR measurements, confirmed the assumption of the calorimetric experiments that first the aluminum orthophosphate was dissolved and then a polycondensation to an amorphous aluminosilicate network occurred. The different amounts of amorphous phases formed as a function of the alkalinity of the sodium silicate solution, indicate that tetrahydroxoaluminate species were formed during the dissolution of the aluminum orthophosphate, which reduce the pH value. This led to no further dissolution of the aluminum orthophosphate, which remained unreacted.

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.

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.

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.

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.

Consolidation mechanism of materials obtained from sodium silicate solution and silica-based aggregates

2011 ◽  
Vol 357 (15) ◽  
pp. 3013-3021 ◽  
Author(s):  
Séka Simplice Kouassi ◽  
Monique Tohoué Tognonvi ◽  
Julien Soro ◽  
Sylvie Rossignol
Keyword(s):  
Sodium Silicate ◽  
Sodium Silicate Solution ◽  
Silicate Solution

scholarly journals Pengaruh Keasaman Medium dan Imobilisasi Gugus Organik pada Karakter Silika Gel dari Abu Sekam Padi

2005 ◽  
Vol 8 (3) ◽  
pp. 74-80
Author(s):  
Sriyanti Sriyanti ◽  
Taslimah Taslimah ◽  
Nuryono Nuryono ◽  
Narsito Narsito
Keyword(s):  
Sodium Silicate ◽  
Silica Gel ◽  
Sodium Silicate Solution ◽  
Thiol Group ◽  
Silicate Solution ◽  
Rice Hull ◽  
Amino Group ◽  
Rice Hull Ash ◽  
Host Matrix ◽  
Medium Acidity

Silica gel is well known as a material that may be used as adsorbent, host matrix for catalyst, etc. Hence, synthesis of silica gel from rice hull ash has been done by evaluation of the effect of medium acidity and organic group immobilized in the snythesis of silica gel.Synthesis of silica gel was done by adding sodium silicate solution from rice hull ash to hydrochloric acid until pH 3, 5 and 7. Immobilization of thiol group and amino group in silica was done by adding 3-mercaptopropyltrimethoxysilane or 3-aminopropyl-trimethoxysilane to sodium silicate solution and hydrochloride acid solution until pH: 7. The products were characterized by X-ray deffractometer and FTIR Spectroscopy.Results showed that porousitas of silica increased with increasing medium acidity ( decreasing pH medium).Immobilization thiol or amino group in silica added a functional group on silica but did not destroy primary structure of silica gel.Key Words: Silica Gel, Rice Hull Ash, 3-mercaptopropyltrimethoxysilane, 3-aminopropyl-trimethoxysilane.

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