|کد مقاله||کد نشریه||سال انتشار||مقاله انگلیسی||ترجمه فارسی||نسخه تمام متن|
|6467897||1362284||2017||6 صفحه PDF||سفارش دهید||دانلود کنید|
- A novel method for concentrating hydrophobic particles was investigated.
- A binder consisting of a highly concentrated water-in-oil emulsion was used.
- Continuous steady state operation was at least 100 times faster than flotation.
In froth flotation, fine hydrophobic particles selectively attach to the surface of air bubbles, in turn rising through the liquid and then more slowly as part of the foam that emerges from the system. This paper proposes a paradigm shift from the traditional use of air bubbles as the hydrophobic separation medium to potentially a far more powerful version that utilises a novel hydrophobic binder, a concentrated water in oil emulsion. We show empirically the oil consumption increases linearly with the specific surface area of the particles, with an average oil film thickness of 178Â nm for fine coal particles, well below the level required for conventional oil agglomeration. The new approach is ultrafast, achieving agglomeration within seconds under batch conditions, with strong selectivity. We also show for the first time continuous steady state agglomeration can be achieved by simply passing the feed and binder suspensions through a partially closed ball valve. Here the residence time through the valve is less than 0.1Â s. And, by subjecting the agglomerated product to further shear, the emulsion is inverted, releasing bound water. Pressure driven filtration then delivers remarkably low product moistures. Operational aspects of this new technology are discussed.
Journal: Chemical Engineering Science - Volume 158, 2 February 2017, Pages 439-444