Recovery of ink particles in a concurrent column flotation

Abstract

Deinked pulp is made from recycled paper in an industrial process called deinking. In this process, printing ink is removed from paper fibres. This research demonstrates the deinking process and discusses factors associated with the collection of released ink particles by bubbles. Flotation is introduced as a technology for the creation of ink-laden bubbles and for the removal of the ink-concentrated froth. A downward concurrent column reactor has been designed, manufactured, and used in a series of two-phase flow experiments. The objective is to measure the liquid and gas retention time to highlight the most effective features associated with bubble particle attachment/detachment. A residence time of <10 s in the downcomer and 20 s in total was found to be sufficient for the collection and recovery of ink particles. It has been concluded that concurrent column reactors are potentially efficient for removing ink from paper fibres.