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The role of the pulp-froth interface on particle detachment and selectivity. Adv Colloid Interface Sci 2021; 287:102296. [PMID: 33321332 DOI: 10.1016/j.cis.2020.102296] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 10/07/2020] [Accepted: 10/17/2020] [Indexed: 11/22/2022]
Abstract
The region between the pulp and the froth also known as pulp/froth interface in mineral flotation processes separates the pulp from the froth. Various researchers suggest particle detachment occurs around this region significantly affecting mineral recovery and grade. One of the causes pointed out is sudden deceleration of bubble-particle aggregate upon collision with the interface while another theory suggests detachment to be caused by bubble coalescence. A possible cause of divergence in views may be in the different methods of investigation employed. Though, more than several researchers indicate that detachment occurs, it is not conclusive whether kinetic energy changes or bubble coalesce or a combination of the two is responsible for detachment if any. Thus, this review examines and presents work that has been done on the role of the pulp-froth interface on particle detachment and selectivity. The review also considers the behaviour of a bubble with various interface as found in literature with a view of inferring the dominant cause of detachment at the interface.
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Xing Y, Gui X, Pan L, Pinchasik BE, Cao Y, Liu J, Kappl M, Butt HJ. Recent experimental advances for understanding bubble-particle attachment in flotation. Adv Colloid Interface Sci 2017; 246:105-132. [PMID: 28619381 DOI: 10.1016/j.cis.2017.05.019] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 05/29/2017] [Accepted: 05/30/2017] [Indexed: 11/27/2022]
Abstract
Bubble-particle interaction is of great theoretical and practical importance in flotation. Significant progress has been achieved over the past years and the process of bubble-particle collision is reasonably well understood. This, however, is not the case for bubble-particle attachment leading to three-phase contact line formation due to the difficulty in both theoretical analysis and experimental verification. For attachment, surface forces play a major role. They control the thinning and rupture of the liquid film between the bubble and the particle. The coupling between force, bubble deformation and film drainage is critical to understand the underlying mechanism responsible for bubble-particle attachment. In this review we first discuss the advances in macroscopic experimental methods for characterizing bubble-particle attachment such as induction timer and high speed visualization. Then we focus on advances in measuring the force and drainage of thin liquid films between an air bubble and a solid surface at a nanometer scale. Advances, limits, challenges, and future research opportunities are discussed. By combining atomic force microscopy and reflection interference contrast microscopy, the force, bubble deformation, and liquid film drainage can be measured simultaneously. The simultaneous measurement of the interaction force and the spatiotemporal evolution of the confined liquid film hold great promise to shed new light on flotation.
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Affiliation(s)
- Yaowen Xing
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China; Chinese National Engineering Research Center of Coal Preparation and Purification, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China; Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Xiahui Gui
- Chinese National Engineering Research Center of Coal Preparation and Purification, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China; Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
| | - Lei Pan
- Department of Chemical Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton 49931, USA
| | - Bat-El Pinchasik
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Yijun Cao
- Chinese National Engineering Research Center of Coal Preparation and Purification, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China
| | - Jiongtian Liu
- Chinese National Engineering Research Center of Coal Preparation and Purification, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China
| | - Michael Kappl
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
| | - Hans-Jürgen Butt
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
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Wang G, Nguyen AV, Mitra S, Joshi J, Jameson GJ, Evans GM. A review of the mechanisms and models of bubble-particle detachment in froth flotation. Sep Purif Technol 2016. [DOI: 10.1016/j.seppur.2016.06.041] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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van Deventer J, Feng D, Burger A. Transport phenomena at the pulp–froth interface in a flotation column: II. Detachment. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.minpro.2003.11.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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