Effects of Power Ultrasound on Precipitation Process of Sodium Silicate Solutions

2015 ◽  
pp. 109-116 ◽  
Author(s):  
Tiepeng Li ◽  
Jilai Xue ◽  
Wenbo Luo ◽  
Jun Zhu
Keyword(s):  
Sodium Silicate ◽  
Precipitation Process ◽  
Power Ultrasound

Effects of Power Ultrasound on Precipitation Process of Sodium Silicate Solutions

2015 ◽  
pp. 109-116
Author(s):  
Tiepeng Li ◽  
Jilai Xue ◽  
Wenbo Luo ◽  
Jim Zhu
Keyword(s):  
Sodium Silicate ◽  
Precipitation Process ◽  
Power Ultrasound

Preparation of the Silica Micro-Spheres by Chemical Precipitation Process

2012 ◽  
Vol 602-604 ◽  
pp. 259-264 ◽  
Author(s):  
Bin Wen ◽  
Chun Qing Huo ◽  
Cong Hao Li ◽  
Long Zhang
Keyword(s):  
Ethyl Acetate ◽  
Sodium Silicate ◽  
Average Particle Size ◽  
Sodium Dodecyl ◽  
Sodium Dodecyl Benzene Sulfonate ◽  
Chemical Precipitation ◽  
Precipitation Process ◽  
Average Particle ◽  
Optimum Reaction ◽  
Addition Amount

Silica micro-spheres were prepared from sodium silicate at room temperature with ethyl acetate as the precipitant. The effect of process parameters on the yield and the morphology of SiO2 powders was systematically investigated and the optimum reaction condition was confirmed as follows: the concentration of sodium silicate was 0.6 mol/L, the total addition amount of the blend surfactants of PEG-1000 and sodium dodecyl benzene sulfonate (SDBS) was 2.1% and the blend ratio was 20:1, the addition amount of ethanol and ethyl acetate were 5.0% and 8.0%, respectively, the stirring rate was 600 rpm and the reaction time was 4.0 hours. The average particle size was 400 nm and the yield was 93.8% .The product was characterized by scanning electron microscope, Infrared Spectroscopy, and X-ray powder diffraction.

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.

Characterization of Rare-Earth Fluoride Anti-Stokes Phosphors by Scanning arid Transmission Electron Microscopy

1971 ◽  
Vol 29 ◽  
pp. 142-143
Author(s):  
N. M. P. Low ◽  
L. E. Brosselard
Keyword(s):  
Electron Microscopy ◽  
Rare Earth ◽  
Elevated Temperatures ◽  
Stoichiometric Composition ◽  
Rare Earth Ions ◽  
Crystalline Solid ◽  
Precipitation Process ◽  
Rare Earth Fluoride ◽  
Earth Fluoride ◽  
Rare Earth Fluorides

There has been considerable interest over the past several years in materials capable of converting infrared radiation to visible light by means of sequential excitation in two or more steps. Several rare-earth trifluorides (LaF3, YF3, GdF3, and LuF3) containing a small amount of other trivalent rare-earth ions (Yb3+ and Er3+, or Ho3+, or Tm3+) have been found to exhibit such phenomenon. The methods of preparation of these rare-earth fluorides in the crystalline solid form generally involve a co-precipitation process and a subsequent solid state reaction at elevated temperatures. This investigation was undertaken to examine the morphological features of both the precipitated and the thermally treated fluoride powders by both transmission and scanning electron microscopy.Rare-earth oxides of stoichiometric composition were dissolved in nitric acid and the mixed rare-earth fluoride was then coprecipitated out as fine granules by the addition of excess hydrofluoric acid. The precipitated rare-earth fluorides were washed with water, separated from the aqueous solution, and oven-dried.

Biorefinery implementation for recovery debottlenecking at existing pulp mills- Part II: Techno-economic evaluation

TAPPI Journal ◽  
2012 ◽  
Vol 11 (8) ◽  
pp. 17-24 ◽  
Author(s):  
HAKIM GHEZZAZ ◽  
LUC PELLETIER ◽  
PAUL R. STUART
Keyword(s):  
Cost Estimation ◽  
Process Model ◽  
Black Liquor ◽  
Pulp Mill ◽  
Value Added ◽  
Economic Assessment ◽  
Extraction Process ◽  
Estimation Methods ◽  
Precipitation Process

The evaluation and process risk assessment of (a) lignin precipitation from black liquor, and (b) the near-neutral hemicellulose pre-extraction for recovery boiler debottlenecking in an existing pulp mill is presented in Part I of this paper, which was published in the July 2012 issue of TAPPI Journal. In Part II, the economic assessment of the two biorefinery process options is presented and interpreted. A mill process model was developed using WinGEMS software and used for calculating the mass and energy balances. Investment costs, operating costs, and profitability of the two biorefinery options have been calculated using standard cost estimation methods. The results show that the two biorefinery options are profitable for the case study mill and effective at process debottlenecking. The after-tax internal rate of return (IRR) of the lignin precipitation process option was estimated to be 95%, while that of the hemicellulose pre-extraction process option was 28%. Sensitivity analysis showed that the after tax-IRR of the lignin precipitation process remains higher than that of the hemicellulose pre-extraction process option, for all changes in the selected sensitivity parameters. If we consider the after-tax IRR, as well as capital cost, as selection criteria, the results show that for the case study mill, the lignin precipitation process is more promising than the near-neutral hemicellulose pre-extraction process. However, the comparison between the two biorefinery options should include long-term evaluation criteria. The potential of high value-added products that could be produced from lignin in the case of the lignin precipitation process, or from ethanol and acetic acid in the case of the hemicellulose pre-extraction process, should also be considered in the selection of the most promising process option.

Study on the Chemical Modification Process of Jute Fiber

TAPPI Journal ◽  
2010 ◽  
Vol 9 (2) ◽  
pp. 23-29 ◽  
Author(s):  
Wei-ming Wang ◽  
Zai-sheng Cai ◽  
Jian-yong Yu
Keyword(s):  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Treatment Time ◽  
Jute Fiber ◽  
Process Conditions ◽  
Silicate Concentration ◽  
Sodium Hydroxide Concentration ◽  
Liquor Ratio ◽  
Degumming Process ◽  
Selection Of

Degumming of pre-chlorite treated jute fiber was studied in this paper. The effects of sodium hydroxide concentration, treatment time, temperature, sodium silicate concentration, fiber-to-liquor ratio, penetrating agent TF-107B concentration, and degumming agent TF-125A concentration were the process conditions examined. With respect to gum decomposition, fineness and mechanical properties, sodium hydroxide concentration, sodium silicate concentration, and treatment time were found to be the most important parameters. An orthogonal L9(34) experiment designed to optimize the conditions for degumming resulted in the selection of the following procedure: sodium hydroxide of 12g/L, sodium silicate of 3g/L, TF-107B of 2g/L, TF-125A of 2g/L, treatment time of 105 min, temperature of 100°C and fiber to liquor ratio of 1:20. The effect of the above degumming process on the removal of impurities was also examined and the results showed that degumming was an effective method for removing impurities, especially hemicellulose.

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