№70-12

Research of the process of crushing graphite grinding in a central mill

І. Ostashko¹, V. Karpenko¹

¹Ukrainian State University of  Chemical Technology, Dnipro, Ukraine

Coll.res.pap.nat.min.univ. 2022, 70:126-135

https://doi.org/10.33271/crpnmu/70.126

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ABSTRACT

Purpose. To obtain ultrafine scaly graphite, it is necessary to analyze and justify the grinding equipment, which allows to obtain a product of a given class. The most appropriate equipment for this purpose is a shock-type centrifugal mill.

Methodology. The work used a complex of tested research methods, which included: laser diffraction analysis, optical microscopy. Also, statistical and mathematical processing of experimental data based on applied computer programs; experimental studies in the laboratory.

Findings. They consist in establishing the regularities of the process of grinding scaly graphite in a centrifugal-impact mill with a static graphite classifier built into the mill using an air flow. According to the results of the study, it was established that graphite can be crushed to a final average size of 10 microns. To obtain a smaller size, you need to use other, more energy-intensive mills. These can be rotary-vortex mills with high efficiency or ball mills (mainly vibrating mills, which have a higher efficiency than conventional ball mills). The value of the coefficients of the equation of kinetics of the grinding process of scaly graphite is determined, which makes it possible to predict productivity by class and grinding time for a given average diameter of the product. The paper shows the feasibility of using a centrifugal shock mill for grinding scaly graphite.

Originality. The technology of grinding flaky graphite to obtain a product of a given dispersion class is proposed. For the first time, according to the results of experimental studies, the value of the constants of the equation of kinetics of the grinding process was established. The distribution curves of the granulometric composition of crushed scaly graphite in the centrifugal mill are constructed depending on the grinding time.

Practical implementation. According to the results of the study, equipment for grinding scaly graphite with the production of a product with an average particle diameter of 10 microns was proposed. The expediency of using a centrifugal mill is substantiated and the effectiveness of the system of classification and removal of the grinding product from the grinding chamber of the mill is shown.

Keywords: flake graphite, grinding, dispersion, kinetics of grinding, centrifugal mill.

References

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