Paper making and fiber liberation – Processes of chemical liberation – recovery or purification... – With regeneration – reclamation – reuse – recycling or...
Reexamination Certificate
2007-11-06
2007-11-06
Hug, Eric (Department: 1731)
Paper making and fiber liberation
Processes of chemical liberation, recovery or purification...
With regeneration, reclamation, reuse, recycling or...
C162S029000, C162S030100, C423SDIG030
Reexamination Certificate
active
10503812
ABSTRACT:
The improved process is achieved by introducing depuration of green liquor and lime before causticization and two special causticization steps in causticization procedure of conventional chemical recovery processes. It not only avoids the generation of waste residue (lime mud) from the beginning and saves the re-burning and filling land of lime mud, but also can directly produce a series of precipitated calcium carbonate products with various particle sizes by regulating process conditions while alkali is recovered. The CaCO3products include CaCO3wherein ≧50% of CaCO3has a particle size below 2 μm, CaCO3wherein ≧90% of CaCO3have a particle size below 2 μm, and a superfine CaCO3having an average particle size <1 μm. The CaCO3obtained by this process can be directly used for papermaking and other industrial applications.
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Ai Dong
Ai Tianzhao
Dong Xuezhi
Ai Dong
Ai Tianzhao
Dong Xuesheng
Dong Xuezhi
Hug Eric
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