The influence of the rotation frequency of a planetary ball mill on the limiting value of the specific surface area of the WC and Co nanopowders

2020 ◽  
Vol 31 (9) ◽  
pp. 3937-3946
Author(s):  
Maksim Dvornik ◽  
Elena Mikhailenko
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Ball Mill ◽  
Rotation Frequency ◽  
Planetary Ball Mill ◽  
Limiting Value

A simple approach for producing high aspect ratio fluorohectorite nanoplatelets utilizing a stirred media mill (ball mill)

Clay Minerals ◽  
2012 ◽  
Vol 47 (3) ◽  
pp. 341-353 ◽  
Author(s):  
M. Ziadeh ◽  
B. Chwalka ◽  
H. Kalo ◽  
M. R. Schütz ◽  
J. Breu
Keyword(s):  
Shear Stress ◽  
Aspect Ratio ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Ball Mill ◽  
Particle Diameter ◽  
Batch Size ◽  
Full Potential ◽  
Stirred Media Mill

AbstractThe potential of platy nanofillers like clays in polymer nanocomposites is mostly determined by their aspect ratio. The degree of improvement that may be achieved in respect to reinforcement, gas-barrier properties and flame retardancy critically depends on the aspect ratio. Thus, increasing the aspect ratio is highly desirable in order to explore the full potential of the clay filler. Mechanical shear stress as generated in the grinding chamber of a stirred media mill (ball mill) induced an efficient exfoliation of highly hydrated and therefore ‘shear-labile’ synthetic Mg-fluorohectorite in aqueous dispersion. The attainable degree of exfoliation can be tuned and controlled through the shear forces applied by changing process parameters such as solid content and grinding media diameter. Characterization and evaluation of the exfoliation efficiency during milling was achieved by combining and cross-validating data obtained by powder X-ray diffraction (XRD), static light scattering (SLS), specific surface area measurements applying the Brunauer-Emmett-Teller (BET) equation, and scanning electron microscopy (SEM). This led to the identification of optimal processing parameters, allowing for control of the degree of exfoliation and, consequently, the aspect ratio of the nanoplatelets. Not surprisingly, besides exfoliation, increasing the magnitude of the shear stress also resulted in some reduction in platelet size.The clay platelets obtained showed a high average aspect ratio (>600), several times greater than that of original synthetic fluorohectorite. The increase of aspect ratio was reflected in a significant enhancement of both specific surface area and cation exchange capacity (CEC) of the external basal surfaces. This method has substantial advantages compared to microfluidizer processing with respect to feasibility, batch size and particle diameter size preservation. The exfoliated nanoplatelets obtained by milling have great potential to improve mechanical properties of polymer layered silicate nanocomposites (PLSN).

scholarly journals A Kinetic Study of Micronization Grinding of Dry Mica in a Planetary Ball Mill

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Ljubiša Andrić ◽  
Anja Terzić ◽  
Zagorka Aćimović-Pavlović ◽  
Milan Trumić ◽  
Milan Petrov ◽  
...  
Keyword(s):  
Specific Surface ◽  
Diffraction Analysis ◽  
Kinetic Study ◽  
Surface Area ◽  
Ball Mill ◽  
Amorphous State ◽  
Planetary Ball Mill ◽  
X Ray Diffraction ◽  
X Ray ◽  
Time Periods

This paper presents results of the research of micronization grinding of dry mica in a planetary ball mill. Investigation was conducted in order to improve the quality and to obtain clearly defined properties and characteristics of mica powder. The micronization grinding of dry mica was performed in four time periods: 30, 60, 120, and 360 minutes. The micronized powder was investigated by means of differential thermal and thermogravimetric analyses, analysis of the degree of micronization, the specific surface area analysis, and X-ray diffraction analysis. The achieved results pointed out that dry mica micronization grinding which exceeds 360 minutes is recommended for this type of mill. However, it was also shown that the micronized mica produced by means of planetary ball mill after extra long periods of micronization grinding can pass into amorphous state.

scholarly journals Criteria-Based Generalization of Mechanochemical Destruction Parameters of Cobalt-Containing Compounds when Disposing Current Sources

2021 ◽  
Vol 27 (4) ◽  
pp. 625-635
Author(s):  
V. M. Retivov ◽  
A. M. Gonopolskiy ◽  
D. A. Makarenkov ◽  
V. I. Nazarov ◽  
A. P. Popov
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Dimensional Analysis ◽  
Specific Surface Area ◽  
Ball Mill ◽  
Operating Parameters ◽  
Combined Processes ◽  
Target Product ◽  
Power Sources ◽  
Lithium Cobalt

The technology of utilization of spent lithium-cobalt power sources is considered, including the stages of opening batteries in a shredder, secondary grinding in a rotary knife mill and mechanochemical destruction in a ball mill to obtain mechanically activated particles with the required characteristics of specific surface area and porosity. It is shown that the combined processes of leaching and extraction with mechanically activated particles can increase the yield of the target product. For a complex set of mechanical and technological effects on structured particles of lithium-cobalt current sources, it is proposed to use the method of dimensional analysis to assess the contribution of operating parameters in the form of dimensionless criterion equations.

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