Phosphonates in kraft pulping and brown stock washing of Eucalyptus pulps

FELISSIA, F.E., AREA, M.C

APPITA JOURNAL

Technical association for the pulp and paper industry of Australia and New Zealand

Lugar: Carlton; Año: 2004 vol. 57 p. 30 - 34

1038-6807

This work studies phosphonates performance when added in Kraft cooking of Eucalyptus spp. (presumed E. grandis) and brown stock washing. Results show that DTPMPA (diethylene triamine penta (methylene phosphonic acid)) is effective to reduce metallic ions when applied in brown stock washing, producing better levels of physical properties than the control. SPAP (Sodium salt solution of Polyaminophosphonic acids) increased physical properties when applied only in cooking, but it show best performance in metals removal when dosed in brown stock washing. Another phosphonate known as HEDP (1-Hydroxy ethylidene diamine (1, 1- diphosphonic acid), EDTA (Ethylene diamine tetra acetic acid) and a strong acid washing were compared afterwards with DTPMPA and SPAP. DTPMPA and SPAP addition did not produce significant differences in Mg, Cu and Fe content in pulps, while Mn reduced to very low levels. HEDP did not produce any difference in metallic ions content when contrasted with a not treated pulp.