Study on the Flotation Behavior of Fine Coal in the Cyclonic-Separation Process.

Fine-mineral separation has been a difficult problem in the mineral-processing field. A new cyclonic-flotation system was designed to solve the fine-mineral-recovery problem. Its design and operation are different from those of other cyclonic-flotation columns. In this study for the new cyclonic column, optimal reagent dosages, solid concentration, and aeration rate were determined. Many factors influence the operation of column flotation; however, in this study, mainly the effect of the circulation rate on the flotation behavior of the wide and narrow particle-size ranges of coal was investigated. The chosen circulation rates were 0.895, 1.044, 1.210, 1.369, 1.461, 1.578, 1.653, and 1.752 m/s. The wide particle size refers to a value of less than 0.5 mm. The narrow particle-size ranges refer to values from -250 to +75 μm, -75 to +45 µm, v45 µm, and +250 µm. The results showed that the combustible recovery of the narrow-size particles increased first and then decreased with the increasing circulation rate. The combustible recovery order of the narrow-size ranges in the same flotation time was as follows: -250 to +75 µm > -75 to +45 µm > -45 µm > +250 µm. [ABSTRACT FROM AUTHOR]