The influence of some parameters on bubble average diameter in an electroflotation cell by laser diffraction method. Issue 3 (September 2016)

• Record Type: Journal Article
• Authors: da Cruz, Samantha Grisol; Dutra, Achilles J.B.; Monte, Marisa B.M.
• Is Part Of: Journal of environmental chemical engineering. Volume 4:Issue 3(2016:Sep.)
• Page Start: 3681
• Page End: 3687
• Publication Date: 2016-09
• Subjects: Electroflotation -- Bubble size -- Electrodes -- Laser diffraction; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2016.05.017
• Languages: English
• ISSNs: 2213-2929

Abstract

Graphical abstract: Highlights: The smaller bubbles, with diameter around 31 μm, were obtained with the stainless steel mesh cathode, at high pH values. The higher the current density the smaller is the bubbles average size. The sodium oleate addition lead to an increase in the bubble size, when bubbles with diameter between 40 and 58 μm were obtained. The conditions of pH and current density that enabled the generation of small bubbles contributing to high phosphate fines recovery. Abstract: The distribution of micro-bubbles generated by the electroflotation process has great importance in the flotation process for fine and ultrafine particles. The objective of this study was to evaluate the influence of some parameters on the average bubble size, generated in an electroflotation cell, on 316 stainless steel cathodes with different geometries, surface finishing, and a Ti/RuO2 mesh as an anode, by the laser diffraction method and image analysis. The average bubble size determination was conducted at different pH values, different cathode surfaces, and different types of collector. Results show that an increase in pH and current density led to a decrease of the bubble size, and that mesh electrodes and electrodes polished with coarser grit sandpaper give smaller gas bubbles. Conversely, when Flotigam EDA, sodium N-lauroyl sarcosinate or sodium oleate were added, larger bubbles were observed. Under the conditions of generation of small bubbles, higher recoveries of fine phosphate particles were observed.