Washing and flotation deinking: In flotation deinking Fatty Acid Base Surfactants at a constant pH 8. Surfactants play three roles in flotation deinking; (1) as a dispersant to separate the ink particles from the fiber surface and prevent the re deposition of separated particles on fiber during flotation, (2) as a collector to agglomerate small ink particles to large ones and change the surface of the particles from hydrophilic to hydrophobic, (3) as a frother to generate foam layer at the top of a flotation cell for ink removal. The resultant pulps from different treatments were washed with tap water. During flotation foam with ink particles was continuously skimmed away from the cell surface. In all furnishes a washing stage was implemented before flotation in order to increase the brightness. After flotation, the pulp was prepared.The present invention concerns a method for deinking waste paper, comprising a pulping step, followed by a so-called flotation step, characterised in that it comprises a step of introducing at least one polyacrylate dispersant, representing 0.05 % to 3.5 % by weight of the mineral fillers of the waste paper. The invention also concerns the use of this specific dispersant during the flotation step of the method for deinking waste paper.
Washing and flotation deinking: In flotation deinking Fatty Acid Base Surfactants at a constant pH 8. Surfactants play three roles in flotation deinking; (1) as a dispersant to separate the ink particles from the fiber surface and prevent the re deposition of separated particles on fiber during flotation, (2) as a collector to agglomerate small ink particles to large ones and change the surface of the particles from hydrophilic to hydrophobic, (3) as a frother to generate foam layer at the top of a flotation cell for ink removal. The resultant pulps from different treatments were washed with tap water. During flotation foam with ink particles was continuously skimmed away from the cell surface. In all furnishes a washing stage was implemented before flotation in order to increase the brightness. After flotation, the pulp was prepared.The present invention concerns a method for deinking waste paper, comprising a pulping step, followed by a so-called flotation step, characterised in that it comprises a step of introducing at least one polyacrylate dispersant, representing 0.05 % to 3.5 % by weight of the mineral fillers of the waste paper. The invention also concerns the use of this specific dispersant during the flotation step of the method for deinking waste paper.
