Nano bubbles Size Distribution Measurement Using Laser Diffraction Technique

Document Type : research - paper

Authors

1 Tarbiat Modares University

2 PhD student, Mineral Processing, Tarbiat Modares University

Abstract

The size distribution of nano-micro bubbles produced by a nano-micro bubble generator was measured by laser diffraction as a reliable and fast method in this investigation. The effects of key parameters including time, type and concentration of frother, gas flow rate and gas type on size distribution of nano-micro bubbles were investigated. The results of nano-micro bubble size as a function of time showed that with the reduction of the absolute zeta potential of nano-micro bubbles and the amount of dissolved oxygen in the solution, the size of nano-micro bubbles was decreased. An increase in the concentration of frother reduces the average size of nano-microbubbles as well as affecting the conventional sized bubbles. It was also revealed that the nano bubbles produced with Aerofroth65 were smaller than those formed with MIBC and Pine oil. It can be concluded the surface tension reduction by Aerofroth65 is more significant than by MIBC and Pine oil. Increased aeration rate (air and oxygen) from 0.1 to 0.3 lmin-1, reduced the average size of nano-micro bubbles. The nano-micro bubbles generated in the presence of oxygen had smaller average size relative to the air nano-micro bubbles because of higher dissolution of oxygen in water in comparison with air and also the higher absolute value of surface zeta potential.

Keywords

Main Subjects