Experimental study on removal of unburned carbon from coal fly ash using flotation column.

The fly ash sample was characterized by size fraction, X-ray diffraction, contact angle measurements and X-ray fluorescence. The function of a new type of frother (KD) which can produce more stable foam than conventional frothers was studied. The effect of the column flotation operating variables on the removal of unburned carbon from the fly ash was also systematically examined. Within the range studied, the optimum frother dosage is 400 g/t, superficial gas velocity is 1. 8 cm/s, froth thickness is about 150-200 mm and circulating pressure is 0. 22 MPa. The results indicate that Cyclonic-Static Micro-bubble Flotation Column (FCSMC ) technique is effective in removing the unburned carbon from coal fly ash. Under the optimized conditions, a cleaning ash with 3. 15% LOI (Loss on Ignition) and 91. 88% RUC(Removal Rate of Unburned Carbon) is obtained. [ABSTRACT FROM AUTHOR]