Correspondence of bubble size and frother partitioning in flotation
来源期刊：中南大学学报(英文版)2014年第6期
论文作者：ZHANG Wei(张炜) Jan E. Nesset James A. Finch
文章页码：2383 - 2390
Key words：flotation; frother; bubble size; frother partitioning; total organic carbon (TOC) analysis; concentration gradient
Abstract: The size of bubbles created in the flotation process is of great importance to the efficiency of the mineral separation achieved. Meanwhile, it is believed that frother transport between phases is perhaps the most important reason for the interactive nature of the phenomena occurring in the bulk and froth phases in flotation, as frother adsorbed in the surface of rising bubbles is removed from the bulk phase and then released into the froth as a fraction of the bubbles burst. This causes the increased concentration in the froth compared to the bulk concentration, named as frother partitioning. Partitioning reflects the adsorption of frother on bubbles and how to influence bubble size is not known. There currently exists no such a topic aiming to link these two key parameters. To fill this vacancy, the correspondence between bubble size and frother partitioning was examined. Bubble size was measured by sampling-for-imaging (SFI) technique. Using total organic carbon (TOC) analysis to measure the frother partitioning between froth and bulk phases was determined. Measurements have shown, with no exceptions including four different frothers, higher frother concentration is in the bulk than in the froth. The results also show strong partitioning giving an increase in bubble size which implies there is a compelling relationship between these two, represented by CFroth/CBulk and D32. The CFroth/CBulk and D32 curves show similar exponential decay relationships as a function of added frother in the system, strongly suggesting that the frother concentration gradient between the bulk solution and the bubble interface is the driving force contributing to bubble size reduction.
ZHANG Wei(张炜)1, 2, Jan E. Nesset2, James A. Finch2
(1. Mining & Mineral Resources Division, Department of Business Administration,
Chinalco China Copper Corporation Limited, Beijing 100082, China;
2. Department of Mining and Materials Engineering, McGill University, Montreal, QC, H3A 0C5, Canada)
Abstract:The size of bubbles created in the flotation process is of great importance to the efficiency of the mineral separation achieved. Meanwhile, it is believed that frother transport between phases is perhaps the most important reason for the interactive nature of the phenomena occurring in the bulk and froth phases in flotation, as frother adsorbed in the surface of rising bubbles is removed from the bulk phase and then released into the froth as a fraction of the bubbles burst. This causes the increased concentration in the froth compared to the bulk concentration, named as frother partitioning. Partitioning reflects the adsorption of frother on bubbles and how to influence bubble size is not known. There currently exists no such a topic aiming to link these two key parameters. To fill this vacancy, the correspondence between bubble size and frother partitioning was examined. Bubble size was measured by sampling-for-imaging (SFI) technique. Using total organic carbon (TOC) analysis to measure the frother partitioning between froth and bulk phases was determined. Measurements have shown, with no exceptions including four different frothers, higher frother concentration is in the bulk than in the froth. The results also show strong partitioning giving an increase in bubble size which implies there is a compelling relationship between these two, represented by CFroth/CBulk and D32. The CFroth/CBulk and D32 curves show similar exponential decay relationships as a function of added frother in the system, strongly suggesting that the frother concentration gradient between the bulk solution and the bubble interface is the driving force contributing to bubble size reduction.
Key words:flotation; frother; bubble size; frother partitioning; total organic carbon (TOC) analysis; concentration gradient
