Paper making and fiber liberation – Processes of chemical liberation – recovery or purification... – Chemical treatment after start or completion of mechanical...
Patent
1981-11-25
1984-03-06
Alvo, Steve
Paper making and fiber liberation
Processes of chemical liberation, recovery or purification...
Chemical treatment after start or completion of mechanical...
162 25, 162 55, 162 65, D21B 104, D21C 910, D21D 502
Patent
active
044352492
ABSTRACT:
Rejects such as knots, shives, slivers, chops, and uncooked and partially cooked wood chips are separated from a pulp slurry and treated to produce a bleachable grade pulp. The rejects are dewatered to a 10-15% consistency, mechanically fiberized, and then delignified at the same 10-15% consistency in the presence of oxygen and alkaline pulping chemicals. The delignification is carried out at 80.degree.-140.degree. C. for 5-120 minutes. The process has low external power requirements, requires no expensive dewatering machinery, and proceeds at a rapid rate to yield a bleachable grade pulp which can be used alone or mixed with other pulp.
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Klepp et al., "Oxygen/alkali Delignification at Kamyr Digester Blowline Consistency" TAPPI, Nov. 1976, vol. 59, No. 11 (77).
Hasvold, "Waste Utilization-Oxygen Delignification of Sulfite Knots", 1978, International Sulfite Conf. (9-13-78).
Elton Edward F.
Magnotta Vincent L.
Markham Larry D.
Martin Andrew C.
Wallick Scott A.
Air Products & Chemicals, Inc.
Alvo Steve
The Black Clawson Co.
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