Preparation Sericite Nanoflakes by Exfoliation of Wet Ultrafine Grinding

2010 ◽  
Vol 178 ◽  
pp. 242-247 ◽  
Author(s):  
Hao Ding ◽  
Xia Xu ◽  
Ning Liang ◽  
Yue Bo Wang
Keyword(s):  
Shear Stress ◽  
Solid Content ◽  
Diameter Ratio ◽  
Mass Ratio ◽  
Optimum Conditions ◽  
Grinding Balls ◽  
Grinding Media ◽  
Ultrafine Grinding ◽  
Ultraviolet Ray ◽  
Grinding Time

Sericite nanoflakes were prepared by exfoliating sericite layers by wet ultrafine grinding. Their appearance morphologies and main properties were characterized. Optimum conditions were studied with the purpose of forming shear stress which was beneficial to the exfoliation of mineral flakes. The results indicated that sericite nanoflakes could be prepared. Mass ratio of grinding media to materials, diameter ratio of grinding balls, solid content of powders and grinding time had significant effects on the preparation. The thicknesses of sericite nanoflakes were 20-80 nm, and the transmittances of ultraviolet ray with wavelength of 190-220 nm were only 0.1%-1%. This demonstrated that sericite nanoflakes had the function of shielding ultraviolet ray.

Study on photocatalytic degradation of methylene blue by TiO2 synthesiszed from titanium slag using a new decomposition agent

2021 ◽  
Vol 11 (1) ◽  
pp. 89-93
Author(s):  
Chinh Tran Van ◽  
Anh Tran Thi Hien ◽  
Tu Ha Thi Cam ◽  
Hoai Truong Viet ◽  
Phuong Nguyen Thi Hoai ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Degradation ◽  
Acid Leaching ◽  
Mass Ratio ◽  
Optimum Conditions ◽  
Titanium Slag

This paper describes a novel process for the synthesis of TiO2 from titanium slag, which is realized via roasting titanium slag with KHSO4, acid leaching and hydrolysis. The results showed that the optimum conditions were a mass ratio of KHSO4 to titanium slag of 6, a temperature of 600 oC for 1,5 hours. Besides, this study investigated the possibility of synthesized TiO2 for photocatalytic degradation of methylene blue.

Study on the Preparation and Amplification Experiment of Al-Pillared Montmorillonite

2011 ◽  
Vol 396-398 ◽  
pp. 1440-1445
Author(s):  
Gang Chen ◽  
Chun Jie Yan ◽  
Jin Feng Shou ◽  
Juan Mei ◽  
Nan Nan Chen
Keyword(s):  
Pilot Scale ◽  
Micropore Volume ◽  
Bet Surface Area ◽  
Scale Production ◽  
Mass Ratio ◽  
Optimum Conditions ◽  
Technical Parameters ◽  
Pillared Montmorillonite ◽  
Commercial Aluminium ◽  
Major Factors

A method of preparation and pilot scale production of Al-pillared montmorillonite has been developed. There is a minimum of time and amount of liquid. And it is simpler to operate than the conventional method of pillaring by using the commercial aluminium hydroxychloride(PAC) powder as the pillaring agent. Here, the effect of the major factors such as the mass ratio of PAC to montmorillonite, the concentration of montmorillonite slurry, the sodium agent pretreatment, washing times and drying temperature on the Al-pillared montmorillonite are studied. Then the optimal technical parameters is determined. XRD, BET surface area and micropore volume are applied in order to study the structure and properties of Al-pillared montmorillonite. As a result, the amplification experiment under the optimum conditions shows that this method offers the potential for extension to an industrial-scale process.

Gas sparged cross-flow microfiltration of biologically treated wastewater

2000 ◽  
Vol 41 (10-11) ◽  
pp. 173-180 ◽  
Author(s):  
L. Vera ◽  
S. Delgado ◽  
S. Elmaleh
Keyword(s):  
Shear Stress ◽  
Membrane Fouling ◽  
Cross Flow ◽  
Solid Content ◽  
Treated Wastewater ◽  
Inorganic Membrane ◽  
Form Complex ◽  
Cross Flow Filtration ◽  
Mass Transport Process ◽  
Flow Filtration

A novel technique was tested for reducing tubular mineral membrane fouling by injecting gas into a cross-flow stream. The injected gas is thought to form complex hydrodynamic conditions inside the microfiltration module, which increase the wall shear stress, preventing the membrane fouling and enhancing the microfiltration mass transfer. The experimental study was carried out with biologically treated wastewater filtered through a tubular inorganic membrane (Carbosep M14). The flux, monotonously increasing with gas velocity, was more than tripled. New dimensionless quantities of shear stress number and resistance number were developed by generalisation of the dimensional analysis already carried out for the steady state flux of classical unsparged cross-flow filtration. A unique formalism allowed then interpreting the experimental results of both classical diphasic filtration and sparged filtration. The main limiting mass transport process was due to the solid content.

scholarly journals Synthesis of NdAlO3 Nanoparticles and Evaluation of the Catalytic Capacity for Biodiesel Synthesis

Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1545 ◽  
Author(s):  
Dionicio-Navarrete ◽  
Arrieta-Gonzalez ◽  
Quinto-Hernandez ◽  
Casales-Diaz ◽  
Zuñiga-Diaz ◽  
...  
Keyword(s):  
Mass Ratio ◽  
Reaction Products ◽  
Optimum Conditions ◽  
Reaction Conditions ◽  
Catalyst Synthesis ◽  
Synthesis Of Nanoparticles ◽  
Biodiesel Synthesis ◽  
Dta Analysis ◽  
Optimum Reaction ◽  
Catalytic Capacity

Biodiesel synthesis was carried out via heterogeneous catalysis of canola oil with nanoparticles of a mixed oxide based on rare earths. The catalyst synthesis (NdAlO3) was carried out based on the method proposed by Pechini for the synthesis of nanoparticles. Thermogravimetric analysis-differential thermal analysis (TGA-DTA) analysis was performed on the nanoparticle precursor gel in order to establish the optimum conditions for its calcination, with these being of 800 °C over 24 h. A pure NdAlO3 compound with an approximate size of 100 nm was obtained. The products of the transesterification reaction were analyzed using gas chromatography, FTIR, and NMR. The optimum reaction conditions were determined, namely, the temperature effect, reaction time, methanol:oil mass ratio, and recyclability of the catalyst. These studies showed the following optimal conditions: 200 °C, 5 h, methanol:oil mass ratio of 6:1, and a constant decrease in the catalytic activity of the catalyst was observed for up to six reuses, which later remained constant at around a 50% conversion rate. The maximum biodiesel yield obtained with the optimum conditions was around 75%. Analysis of the reaction products showed that the residual oil showed a chemical composition different from that of the source oil, and that both the biodiesel and glycerol obtained were of high purity.

The Hydrodynamic Forces Acting on a Long Flexible Circular Cylinder Responding to VIV

2006 ◽  
Author(s):  
P. W. Bearman ◽  
F. J. Huera Huarte ◽  
J. R. Chaplin
Keyword(s):  
Circular Cylinder ◽  
Cross Flow ◽  
Element Model ◽  
Transverse Force ◽  
Diameter Ratio ◽  
Mass Ratio ◽  
Force Coefficients ◽  
Fluid Forces ◽  
Maximum Value ◽  
Vibration Prediction

Distributions of the fluid forces acting along a long flexible circular cylinder free to respond in-line and transverse to a stepped current are presented. Forces are calculated using a finite element model of the cylinder with measured responses providing the input. The length to diameter ratio of the model used was 469, the mass ratio was 3 and the Reynolds number could be varied up to maximum value of approximately 2.6 · 104. Fluid force coefficients for two cases are presented: in the first, the dominant modes are the 2nd cross-flow and the 4th in line. For the second case the leading modes are the 7th and 12th respectively. In general, transverse force coefficients and in-line drag coefficients are found to be larger than those measured for short sections of cylinder undergoing free and forced one and two-dimensional motions. It is anticipated that the results will be of value to developers of vortex-induced vibration prediction methods.

Physical Aging and Thixotropy in Sludge Rheology

2008 ◽  
Vol 18 (1) ◽  
pp. 13495-1-13495-8 ◽  
Author(s):  
J.C. Baudez
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Physical Aging ◽  
Abrupt Change ◽  
Rheological Behaviour ◽  
Critical Value ◽  
Solid Content ◽  
Structural Parameter ◽  
Critical Shear Rate ◽  
A New Technique

Abstract Sewage sludge presents a dual rheological behaviour with an abrupt change between the two regimes. Using a new technique of reconstruction of the velocity profile, the behaviour can be modelled by a unique equation including liquid and solid components but also a structural parameter. It is also rigorously demonstrated that the only one rheological behaviour in steady state in the liquid regime is a truncated power-law which can be defined only for a shear rate and a shear stress higher than a critical value, γ̇c and τc. Moreover, the critical shear rate and shear stress increase with the solid content and depend on the fractal dimension of flocs which implies that thixotropic effects are all the more important as the sludge is thick and fresh.

scholarly journals Optimization of Operating Parameters on Dry Grinding of Calcite in a Stirred Media Mill Using the Box-Behnken Design

Minerals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 251
Author(s):  
Diler Katircioglu-Bayel
Keyword(s):  
Mass Fraction ◽  
Filling Ratio ◽  
Operating Parameters ◽  
Stirrer Speed ◽  
Solid Mass ◽  
Optimum Conditions ◽  
Box Behnken Design ◽  
Dry Grinding ◽  
Grinding Time ◽  
Stirred Media Mill

The optimization of the operating parameters of a stirred media mill in the dry grinding of calcite was investigated. A three-level Box-Behnken design was used for the purpose of examining the impact of four independent factors, the stirrer speed (SS), grinding time (GT), media filling ratio (MFR), and solid mass fraction (SMF), on the product particle size (d50). For the purpose of establishing an empirical correlation between operating parameters and responses, a series of experiments were carried out. Variance analysis showed a reasonably good value for d50 (R2 = 0.965). According to the software solutions, the optimum conditions for minimizing the d50 size were found to be 573 rpm stirrer speed, 11.18 min grinding time, 63% media filling ratio, and 11.52% solid mass fraction, with 3.78 µm for the d50 size. To verify the improvement of grinding, verification tests were performed using the above-mentioned optimum conditions and the average d50 size and standard deviation were found to be 3.83 µm and 0.025, respectively. The average d50 value obtained was smaller than those obtained in the 27 tests. Furthermore, when the optimum result obtained from the experiments was compared with the result obtained using the software, a 22% energy saving was achieved. The impacts of grinding on the structural characteristics of calcite particles were characterized by XRD analysis. XRD measurements indicated that no change was observed in the peak areas of ground calcite specimens compared to the untreated calcite specimen.

Study on Polyurethane Dispersions with PES/PPG and High-Solid Content

2013 ◽  
Vol 864-867 ◽  
pp. 588-591 ◽  
Author(s):  
Xiao Li Wei ◽  
Fa Xing Zhang
Keyword(s):  
Particle Size ◽  
Shape Memory ◽  
Solid Content ◽  
Plastic Behavior ◽  
Mass Ratio ◽  
High Solid Content ◽  
High Solid ◽  
Shape Memory Behavior ◽  
Good Shape ◽  
Polyurethane Dispersions

A series of novel stable and high-solid-content polyurethane were prepared by self-emulsification,use PES and PPG as mixed soft segments.Influence of APAETMS content and mole ratio of PES/PPG on properties of polyurethane dispersions and films were analyzed .Results show that: the cross-linked complex were multivariate distribution in particle size. With an increase of the mass ratio of PES and PPG and content of APAETMS average particles diameter of polyurethane dispersions became bigger , poly-dispersion became wider., solid content of dispersions decrease.. It is also noticed that the high-solid-content dispersions exhibit a pseudo-plastic behavior, when the mass ratio of PES and PPG is 1:3 and content of APAETMS is 1%, the solid content of dispersions is up to 55%. The film also has a good shape memory behavior.

Apparent porosity of porous bioceramics prepared with small organic foam spheres as the pore-making reagent

Clay Minerals ◽  
2010 ◽  
Vol 45 (4) ◽  
pp. 449-452 ◽  
Author(s):  
Chuisheng Zeng ◽  
Xiaoming Chen ◽  
Yuhua Yan ◽  
Xiaoying Tang ◽  
Yilong Liang ◽  
...  
Keyword(s):  
Temperature Rise ◽  
Sintering Temperature ◽  
Heating Time ◽  
Apparent Porosity ◽  
Mass Ratio ◽  
Optimum Conditions ◽  
Technical Parameters ◽  
Beta Tricalcium Phosphate ◽  
Main Factors ◽  
Porous Bioceramics

AbstractThis study focuses on the main factors determining the apparent porosity of porous bioceramics prepared using small organic foam spheres as the pore-making reagent, in order to determine the best technical parameters for preparing porous bioceramics. In every experiment, only one of these factors (the time of heating, the sintering temperature, the mass ratio between small organic foam spheres and beta-tricalcium phosphate (β-TCP) powder, and the rate of the temperature rise) was changed, while the others were kept constant. In each case the apparent porosity was tested and the relation between the specific variable and apparent porosity was observed. Finally, the optimum technical parameters were deduced. The apparent porosity shows an inverse linear relation to the time of heating and the sintering temperature, and is approximately proportional to the mass ratio between the small organic foam spheres and the β-TCP powder and the rate of temperature rise. These factors have important influences on the apparent porosity. The optimum conditions were: heating time (soak time) 120 min, sintering temperature 850ºC, mass ratio 0.25, and a rate of temperature increase of 120ºC h–1.

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