Conversion of Paper Mill Sludge into Pulp Substitute and Papermaking Clay. Phase 2

摘要

The objective was to develop technology to convert the fiber fines/clay fraction of paper mill sludge or deinked white office wastepaper into a papermaking filler product after the long fiber fraction had been extracted, cleaned, and bleached to produce a papermaking pulp product. The goal was to increase the brightness and decrease the specific resistance of the fiber fines/clay samples. A simple, low cost, and potentially patentable technique was discovered that significantly lowered the specific resistance, and a simple bleaching technique compatible with the technique to lower the specific resistance was discovered. However, the brightness gains were often insufficient, even at high bleach dosages and fiber fines/clay samples derived from deinked white office wastepaper were not susceptible to bleaching. No commercially viable technique was discovered to remove the very fine ink particles from such samples. Nevertheless, a filler product suitable for paperboard and some fine papermaking applications where a high brightness filler is not required can be produced that should have acceptable drainage characteristics on a paper or board machine.