Separation of cellulose fibres from pulp suspension by froth flotation fractionation

Abstract

Flotation of cellulose pulp suspension in paper industry is primarily used for separation of ink particles from cellulose fibres. Entrainment, an unwanted phenomena well described in the field of mineral flotation, also leads to a removal of fibres with the flotation froth. We find that the entrainment phenomena can be used for the separation of long fibres from a fibre pulp suspension, and hence for pulp fractionation. Specifically, we use a 2D bubble column to investigate the influence of (i) bubble size, (ii) wash rate and (iii) stirring on the separation of long fibres from cellulose pulp suspension. Separation of fibres from fibre pulp suspension is tested for mechanical pulp and chemical pulp. We find that size selective recovery yields best result for (i) large bubbles, and (ii) additional washing due to the increase of small particle drainage. However, both strategies lead to a reduction of the total recovery rate. Stirring significantly improved the total recovery and benefited the selective separation. Best results are achieved with small bubbles for chemical pulp. For mechanical pulp, fractionation is more challenging due to lower froth stability, but still fibres with a reduced amount of smaller fraction can be recovered.

Bubble Attachment to Cellulose and Silica Surfaces of Varied Surface Energies: Wetting Transition and Implications in Foam Forming

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Green nanobiopolymers for ecological applications: a step towards a sustainable environment

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“…42 3.1.7 High-intensity ultrasonication. Intense center ultrasonication is the most broadly perceived lab mechanical therapy procedure for liquid conditions 43,44 for cell agitating impacts. This advancement produces possible cavitation, like the chance of trials, expansion, and the breakdown of small gas ascends aer water particles control ultrasonic energy.…”

Molecular Dynamics Study of the Bulk and Interface Properties of Frother and Oil with Saltwater and Air

“…A similar mechanism is utilized in froth flotation. Surfactant-like molecules are added to the feed in dilute concentrations to promote the formation of a skimmable froth, which enhances the collection of hydrophobic species on the bubbles. − Such froth flotation methods have been employed and well-studied in processes such as mineral beneficiation and paper recycling. − Research has been focused on various aspects of this technology, including surfactant selection and concentration, rising bubble behavior, surface froth stability, flotation unit designs, and particle properties and novel applications . As one of the newer applications, surfactant-induced froth can separate oil from water in a similar manner to how hydrophobic particles are separated in mineral recovery.…”