Abstract
Metal cation exchange with unbleached fibers was investigated using hardwood kraft pulps produced with phosphonate addition in the digester. Metal contents and their sorption by the dissolved kraft lignin in the black liquor were also quantified. Ion exchange constants for the calcium-sodium pair were determined. Reductions of Fe, Mn and Zn are most likely responsible for the brightness improvement of resulting pulps as well as their beneficial responses in subsequent bleaching. Metal-ions especially calcium on fibers are significantly decreased by-phosphonates addition in cooking; they eventually enter the black liquor and form soluble phosphonate-cation groups. Approximately 800-1000ppm of calcium was retained on fibers while less than 67ppm were found in precipitated kraft lignin. The overall solids content within the cooking system was increased by 0.6-1.3%.
| Original language | English (US) |
|---|---|
| Title of host publication | 2003 TAPPI Fall Technical Conference |
| Subtitle of host publication | Engineering, Pulping and PCE and I, Proceedings |
| Pages | 373-392 |
| Number of pages | 20 |
| State | Published - Dec 1 2003 |
| Event | 2003 TAPPI Fall Technical Conference: Engineering, Pulping and PCE and I - Chicago, IL, United States Duration: Oct 26 2003 → Oct 30 2003 |
Other
| Other | 2003 TAPPI Fall Technical Conference: Engineering, Pulping and PCE and I |
|---|---|
| Country/Territory | United States |
| City | Chicago, IL |
| Period | 10/26/03 → 10/30/03 |