# Impact of Temperature, pH, Electrolytes, Approach Speed, and Contact Area on the Coalescence Time of Bubbles in Aqueous Solutions with Methyl Isobutyl Carbinol

## TL;DR

This study examines how factors like temperature, pH, and salt affect bubble coalescence in mineral flotation processes, aiming to improve industrial efficiency and sustainability.

## Contribution

The study provides a systematic analysis of multiple physicochemical factors influencing bubble coalescence in MIBC solutions under flotation-relevant conditions.

## Key findings

- Coalescence is delayed at lower temperatures, alkaline pH, and high salt concentrations.
- Larger interfacial contact areas between bubbles also delay coalescence.
- Approach speed had an insignificant effect on coalescence within the studied range.

## Abstract

The prevention of bubble coalescence is essential in various industrial processes, such as mineral flotation, where the stability of air–liquid interfaces significantly affects performance. The combined influence of multiple physicochemical parameters on bubble coalescence remains insufficiently understood, particularly under conditions relevant to flotation. This study explores the key factors that influence the inhibition of bubble coalescence in aqueous solutions containing methyl isobutyl carbinol (MIBC), providing a systematic comparative analysis to assess the effect of each variable on coalescence inhibition. An experimental method was employed in which two air bubbles were formed from identical capillaries and brought into contact either head-to-head or side-by-side, then held until coalescence occurred. This setup allows for reliable measurements of coalescence time with minimal variability regarding the conditions under which the bubbles interact. The study examined the effects of several factors: temperature, pH, salt concentration and type, bubble approach speed, contact area, and contact configuration. The results reveal that coalescence is delayed at lower temperatures, alkaline pH conditions, high salt concentrations, and larger interfacial contact areas between bubbles. Within the range studied, the influence of approach speed was found to be insignificant. These findings provide valuable insights into the fundamental mechanisms governing bubble coalescence and offer practical guidance for optimizing industrial processes that rely on the controlled stabilization of air–liquid interfaces. By understanding and manipulating the factors that inhibit coalescence, it is possible to design more efficient and sustainable mineral flotation systems, thereby reducing environmental impact and conserving water resources.