High-consistency bleaching with peroxide and ozone was investigated in
the laboratory and pilot plant. For the ozone stage, the influence of
consistency in the range of 30 to 45% and the influence of fluff qual
ity and ozone charge on Kappa number brightness and strength propertie
s were investigated. The laboratory and pilot plant operation showed c
omparable results. In HC-peroxide bleaching good mixing was only possi
ble in mill and pilot plant scale. The influence of consistency and ca
ustic was measured.