| abstract |
A flotation process for the de-inking of printed waste-paper by treating the paper pulp in the pulper at alkaline pH-values by means of alkali silicate, oxidative bleaches and separating the loosened printing-ink particles from the fibrous material suspension by flotation, in which protein fatty acid condensates are added finely distributed, possibly together with dispersing agents, in a solution or dispersion which is fluid at normal temperature. |