Appeal No. 2001-2443
Application 09/108,541
The Invention
The Appellants’ invention relates to a process for the elemental chlorine-free
bleaching of pulp in a four-stage bleaching process. The first stage is conducted under
alkaline extraction conditions assisted by either oxygen or oxygen and peroxide. The
second is a chlorine dioxide bleaching stage. The third is an alkaline extraction stage
assisted by both oxygen and peroxide. The fourth and final stage is another chlorine
dioxide stage. (Appeal Brief, page 3, lines 7-14).
Filtrate containing chlorinated wastes from one or both of the chlorine dioxide
stages is recycled to the initial extraction stage where the pulp is delignified. Filtrate
from the initial stage is then incorporated into the bleach plant effluent which is not
recycled to a recovery boiler. (Appeal Brief, page 3, lines 15 - 22).
This process is said to result in several advantages including treatment of
chloride-containing filtrate without expensive chloride-removal measures; substantially
reduced AOX, COD and color in the bleach plant effluent; substantially reduced filtrate
volumes; and recycled chlorine dioxide stage filtrate added to brown stock for reducing
pulp consistency. Pulp strength and brightness is said to be good after the process.
(Appeal Brief, page 4, lines 5 - 15).
The Rejection Under 35 U.S.C. § 112, Second Paragraph
Claims 1-24 stand rejected under 35 U.S.C. §112, second paragraph, as being
indefinite for failing to particularly point out and distinctly claim the subject matter which
the Applicants regard as the invention. The Examiner has found that the term
“extraction stage” is misdescriptive of the first stage, which he considers to be a
5
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 Next
Last modified: November 3, 2007