Study of Flotation Deinking of Old Magazine and Mixed Office Waste Paper

The effect of flotation parameters such as flotation consistency, temperature, flotation time, air to pulp ratio, and velocity of pulp flow (turbulence level) on OMG/MOW deinking efficiency was studied by using a high-consistency laboratory pulper and a laboratory deinking cell. The optimized flotation conditions were: flotation consistency 1.1%, 40°C, 8min, air to pulp ratio 40%, velocity of pulp flow 3.5m/s and pH 9.0. By using the optimized flotation conditions, the deinked pulp brightness could reach 70.56%ISO, 11.78%ISO higher than that of the control, the effective residual ink concentration was 108.46 mg/kg, which less than 378.14mg/kg of the control, theoretic deinking efficiency was up to 88.41%.