Experimental Procedure for the Determination of the Critical Coalescence Concentration (CCC) of Simple Frothers

Onur Guven,Orhan Ozdemir,Stoyan I Karakashev,Nikolay A Grozev,Khandjamts Batjargal,Feridun Boylu,Mehmet Sabri Çelik

doi:10.3390/min10070617

Abstract

In this study, the critical coalescence concentrations (CCC) of selected commercial frother solutions, namely polypropylene glycols (PPG 200, 400, and 600), tri propylene glycol (BTPG), triethylene glycol (BTEG), dipropylene glycol (BDPG), and as a reference, methyl isobutyl carbinol (MIBC), were determined using a bubble column based on light absorption. The results for all seven frothers showed that BTEG has the worst bubble inhibiting performance, and PPG 600 has the best bubble inhibiting performance. While critical coalescence concentration (CCC) was found as 3 ppm for PPG 600, it increased to 25 ppm for BTEG. In the case of MIBC, which was the reference point, the CCC value was found as 10 ppm, which was consistent with the literature. The surface tension isotherms of the frothers were determined and analyzed with one of the latest adsorption models. The results indicated that the polypropylene glycol frothers showed more surface activity compared to alcohol or other frothers investigated. This is due to the additional reorganization of the PPG molecules on the air/water interface, thus boosting its surface activity.

Highlights

Flotation has been used for over a century as an important industrial process to recover valuable minerals
Considering very similar results for the coalescence concentration (CCC) value of methyl isobutyl carbinol (MIBC) determined with other methods, it can be concluded that this method is an easy and quick way to determine the extent of bubbles coalescence (CCC)
The CCC values of the frothers correlate well with the adsorption parameters of the frothers, the CCC values are located at the very beginning of the surface tension isotherm

Summary

Introduction

Flotation has been used for over a century as an important industrial process to recover valuable minerals. Besides the contribution of parameters, such as liberation size, reagent type, and other physical and chemical parameters, the effect of frother type and, the size of bubbles, is a key variable in the flotation process [1,2,3,4,5]. A thin liquid film forms when two bubbles approach each other, pressed toward each other by the capillary pressure, which squeezes the liquid between them, thinning the film until it ruptures. This in turn results in “bubble coalescence,” which will eventually change the size of the bubbles [8,9,10]. Since the main aim of the frothers is to control the froth stability and produce fine bubbles, the optimization of bubble size and “coalescence” come into prominence for Minerals 2020, 10, 617; doi:10.3390/min10070617 www.mdpi.com/journal/minerals

Methods

Results

Discussion

Conclusion