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ARS Home » Pacific West Area » Riverside, California » Agricultural Water Efficiency and Salinity Research Unit » Research » Publications at this Location » Publication #354474
Research Project: Identifying, Quantifying and Tracking Microbial Contaminants, Antibiotics and Antibiotic Resistance Genes in Order to Protect Food and Water Supplies

Location: Agricultural Water Efficiency and Salinity Research Unit

Title: Application of depletion attraction in mineral flotation: I. Theory

Author
item CHOI, JUNHYUN - Chonbuk National University
item KIM, GAHEE - Chonbuk National University
item CHOI, SOWON - Chonbuk National University
item KIM, KYUHAN - Korean Advanced Institute Of Science And Technology (KAIST)
item HAN, YOSEP - Chonbuk National University
item Bradford, Scott
item CHOI, SIYOUNG - Korean Advanced Institute Of Science And Technology (KAIST)
item KIM, HYUNJUNG - Chonbuk National University

Submitted to: Minerals
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/30/2018
Publication Date: 10/14/2018
Citation: Choi, J., Kim, G., Choi, S., Kim, K., Han, Y., Bradford, S.A., Choi, S.Q., Kim, H. 2018. Application of depletion attraction in mineral flotation: I. Theory. Minerals. 8(10):451. https://doi.org/10.3390/min8100451.
DOI: https://doi.org/10.3390/min8100451

Interpretive Summary: The interaction of colloids (e.g., microorganisms, clays, and nanoparticles) with surfaces is important for many industrial and environmental applications. However, the relative importance of different types of colloid interactions with air bubbles is not always known. A theoretical study was conducted to investigate the importance of osmotic interactions that can occur when a colloid interacts with an air bubble in the presence of polymers. Results demonstrate the osmotic interaction can control colloid association with the air bubbles under certain solution chemistry conditions. This information will be of interests to scientists and engineers that are using air bubbles to process minerals and to remediate contaminated sites.

Technical Abstract: We investigate the role of depletion interactions in the particle–bubble interactions that determine the attachment capability of particles on the bubble surface in flotation. In this article, we propose a theoretical model that explains how this attractive interaction could enhance flotation efficiency. Two optimum conditions are determined for the concentration and molecular weight of the depletion agent. The optimum concentration can be determined through the extent of surface activity of the depletion agents. The magnitude of the depletion attraction increases as the concentration increases; however, an increase in the concentration simultaneously enhances its surface concentration. The bubble surface adsorption of the depletion agent results in polymer brushes on the bubble surface that produce a large repulsive interaction. In contrast, the optimal molecular weight of the depletion agents is given by the interaction between the depletion agent sizes, which is determined by its molecular weight and Debye length which is determined by the solution ionic strength. We demonstrate that exploiting this depletion interaction could significantly enhance the flotation efficiency and in principal could be used for any particle system.