Selective froth flotation of pitch components from spruce TMP process water

Anders Strand, Dariusz Zasadowski, Magnus Norgren, Erik Hedenström, Stefan Willför, Anna Sundberg

    Research output: Contribution to journalArticleScientificpeer-review


    Selective removal of dissolved and colloidal pitch components from an unbleached thermomechanical pulp (TMP) pressate by addition of a cationic foaming agent, dodecyltrimethylammonium chloride (DoTAC), and subsequent froth flotation was assessed. The experiments were conducted with varying pH, temperature, and concentrations of DoTAC and calcium. The concentrations of pitch components, lignans, and dissolved polysaccharides were determined before and after flotation. All pitch components were removed more efficiently by flotation at pH 5 and 3.5 than by flotation at pH 7.6. Resin and fatty acids were removed to a higher degree than neutral pitch substances at all the tested pH levels. Most of the water-soluble uronic acids and galactoglucomannans stayed in the TMP water after flotation. Froth flotation with DoTAC was an effective way of selectively removing colloidal and dissolved pitch. Removal of pitch, especially of resin acids, at an early stage should be beneficial to the overall papermaking process.
    Original languageUndefined/Unknown
    Pages (from-to)337–346
    Number of pages10
    JournalAppita Journal
    Issue number4
    Publication statusPublished - 2012
    MoE publication typeA1 Journal article-refereed


    • anionic trash
    • Colloidal pitch
    • flotation
    • mechanical pulp
    • wood resin

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