| 摘要 |
<p>A process for delignifying and bleaching a lignocellulosic pulp without the use of elemental chlorine or chlorine-containing compounds by oxygen delignifying (40) the pulp to a K No. of about 10 or less, a viscosity of greater than about 12 cps and a GEB of about 33-43; and thereafter further delignifying (78) the partially delignified pulp by lifting, displacing and tossing the pulp in a radial direction while advancing it in an axial direction in a plug flow-like manner with an effective amount of ozone (88) for a sufficient time to obtain a substantially delignified pulp having a K No. of about 5 or less, a viscosity of at least about 9-10 cps and a GE brightness of at least about 59. The substantially delignified pulp (102) may then be brightened to a final product having a GE brightness of at least about 75, or alternately up to about 83+ by contacting the ozonated pulp with a sufficient amount of a peroxide compound for a time of up to about three hours, with optional mixing of the pulp/peroxide mixture.</p> |
