Dewatering of coal flotation concentrate - via double flotation process for efficient removal of fine waste

摘要

After leaving a flotation plant, 0.3 wt.% max. of oil, w.r.t. the wt. of solids, is mixed with the concentrate, and the mixt. is fed into a centrifuge. The liq. suspension leaving centrifuge is subjected to a second flotation, followed by further removal of water. Flotation agents may or may not be added prior to the second flotation; and the liq. concentrate leaving the second flotation may be recycled to centrifuge. The pref. plant includes a first flotation stage removing waste or deads to obtain a concentrate mixed with 0.05-0.3% oil and fed into centrifuge, from which the solids travel to another centrifuge but the liq. phase flows to a second flotation unit. High flow rates can be used, and the oil consumption is reduced.