TRUE FLOTATION AND PHYSICAL ENTRAINMENT - THE MECHANISMS OF FIBER LOSS IN FLOTATION DEINKING

The mechanisms of fiber loss in flotation deinking were studied using fibers with the same geometry but different surface hydrophobicities. The fiber loss was directly compared with the contact angle of fibers in the pulp suspensions. It was found that both true flotation and phy sical entrainment will contribute to the fiber loss, but physical entr ainment is the major contributor. Fiber geometry and froth structure w ill significantly affect the physical entrainment. Only part of the en trained fibers can be washed away from the froth during water drainage . To reduce fiber loss in flotation deinking, effective control of foa m structure and stability is very important.