Paper making and fiber liberation – Processes of chemical liberation – recovery or purification... – Chemical treatment after start or completion of mechanical...
Reexamination Certificate
2006-05-30
2006-05-30
Alvo, Steve (Department: 1731)
Paper making and fiber liberation
Processes of chemical liberation, recovery or purification...
Chemical treatment after start or completion of mechanical...
C162S078000, C162S080000, C162S090000
Reexamination Certificate
active
07052578
ABSTRACT:
Wood pulp is bleached using hydrogen peroxide as the oxidative bleaching agent in the presence of magnesium hydroxide or magnesium oxide. The bleaching process is carried out in the presence of magnesium hydroxide as the predominant, and preferably essential, source of alkali. The process optionally includes transition metal chelants, such as DTPA or EDTA in the bleaching slurry. The process eliminates the need for added caustic and silicate in such systems and can be carried out at or near neutral pH of 5.0 to 8.5.
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Branch Burton
Genco Joseph
Gibson Aileen R.
Johnson Donna
Wajer Mark T.
Alvo Steve
Marger Johnson & McCollom PC
Martin Marietta Magnesia Specialties Inc.
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