Influence of Pulp Bleaching on Non-Process Elements, 2000 Pulping / Process & Product Quality Conference Proceedings
W. Wang, J. S. Hsieh, A. J. Ragauskas--A softwood kraft pulp, acquired from kraft pulping operation in the southeastern US, was bleached with ECF and TCF sequences, and Non Process
Elements (NPE’s) in the bleached pulps were analyzed by ICP method.
For ECF bleaching, the initial Do-stage is very effective in removing NPE’s, and iron was found to be the most resistant to remove form the fiber during the bleaching. Eo and Eop yield pulp with comparable NPE’s, but the addition of peroxide to an (EO)-stage improves the brightness values of the softwood kraft pulp. Of all the metals studied the loss of calcium from the fiber was the greatest.
For the TCF bleaching, the bulk of NPE’s were removed during pulp bleaching, and iron and copper were the most resistant to remove during oxygen, ozone, peroxide and peracetic acid bleaching.
Influence of Pulp Bleaching on Non-Process Elements, 2000 Pulping / Process & Product Quality Confer