The Effect of Dissolved Organics Substances on the Distribution of Metal Ions in a Pulp Suspension, 2004 Engineering, Pulping, and PCE&I Conference

Metal ions play important role in pulp and papermaking processes. For example, in peroxide bleaching Mg2+ is considered beneficial to the bleaching stage. Mn2+ ion on the other hand is considered detrimental to the peroxide bleaching stage. Moreover, the recent move to mill closure has exacerbated the problems caused by metal ions. Therefore, metal ions control is absolutely necessary in pulp and paper mills. To control metal ions, we must know-what metals ions are present in pulp slurry, what kinds of interaction exist between various metal ions and what kinds of interaction exist between metal ions and fiber. In this study, we looked at how Mg2+ ions interact with fiber in a bleached kraft pulp suspension. Mg2+ ions is added to a pulp suspension and allowed to equilibrate for some time. Some of the Mg2+ ions may be adsorb on the fiber, some may remain in the external solution of the pulp suspension. And lastly some Mg2+ ions may precipitate. Temperature and pH changes may influence the distribution of Mg2+ ions between the external solution and the fiber of the bleached kraft pulp suspension. Furthermore, the addition of weak black liquor (WBL), lignosulfonate (S-lignin), kraft lignin (K-lignin) and other metal ions to the bleached kraft pulp suspension may influence the distribution of Mg2+ ions.