First industrial flotation column in a paperboard recycling plant

First industrial flotation column in a paperboard recycling plant

Ben, Yuxia and Dorris, Gilles and Pagé, Natalie and Gendron, Sylvain and Gurnagul, Norayr and Desrosiers, Christian and Maltais, Patrick

Progress in Paper Recycling 2009

Abstract : We describe the steps that have led to the construction of a small industrial flotation column in an Old Corrugated Container (OCC) recycling plant. First, flotation tests were carried out at Paprican using samples from the mill. Following this evaluation phase, a laboratory column was installed at the mill, where OCC fresh pulp and process rejects were processed in the column. Flotation removed macrostickies, wax, fillers, and organic extractives, while fibre loss was minimal. The laboratory column was then used to develop control algorithms aimed at reducing variations in froth heights and air content in the column. After this successful testing phase, the mill installed a small industrial column of 0.6 m in diameter and 6.0 m in height. Flotation efficiencies in the larger column approached those obtained with the laboratory column. At this stage of development, the mill column is used as an R&D unit to establish its long-term performance and to determine the impact of recovered materials to the main OCC pulp line. Flotation trials to date have shown no negative impact of recovered fibres on mill operation. The R&D column will be in full-time operation this year for the recovery of 2.5-3.5 tpd of fibre from reject streams.