Influence of suspension stability on wet grinding for production of mineral nanoparticles--颗粒学报PARTICUOLOGY

Sakthivel, S., Krishnan, V. V., & Pitchumani, B. (2008). Influence of suspension stability on wet grinding for production of mineral nanoparticles. Particuology, 6(2), 120–124. https://doi.org/10.1016/j.partic.2007.12.001

Influence of suspension stability on wet grinding for production of mineral nanoparticles

S. Sakthivel, Venkatesan V. Krishnan, B. Pitchumani^*

Particle Science and Technology Laboratory, Department of Chemical Engineering, Indian Institute of Technology, New Delhi, India

10.1016/j.partic.2007.12.001

Volume 6, Issue 2, April 2008, Pages 120-124

Received 4 August 2007, Accepted 24 December 2007, Available online 20 March 2008.

E-mail: bpmani@chemical.iitd.ernet.in; b_pitchumani@hotmail.com

Highlights

Abstract

Grinding behavior of nanoparticles in an attritor mill and the minimum achievable particle size are strongly influenced by the suspension stability. In the present work, suspension stability (i.e. ζ-potential) of nanoparticles was studied by measuring pH as a function of grinding time in the wet milling process. It was found that after a certain time in an attritor mill, there is no further size reduction and the average product particle size increases monotonically. One of the reasons is that the production of submicron particles leads to more particle–particle interactions and consequently pH of the suspension decreases with grinding time. Usually pH value is related to suspension stability and it can be enhanced by addition of NaOH solution. The maximum negative ζ-potential of −51.2 mV was obtained at pH of 12 for silica. The higher the ζ-potential with the same polarity, higher will be the electrostatic repulsion between the particles. Hence, the maximum electrostatic repulsion force was maintained by the adjustment of pH value in wet milling. The experiments were conducted at different pH conditions which were maintained constant throughout the experiments and nanosized particles were obtained consequently.

Graphical abstract

Keywords

Suspension stability; ζ-Potential; Nanosilica particle; Attritor mill

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