Appeal No. 1998-1832
Application No. 08/434,331
THE INVENTION
The invention is directed to a process for the production of bleached pulp. The
process requires the presence of two recovery installations. A filtrate containing used
cooking chemicals is contained in the first recovery installation. A filtrate containing used
chlorine-free bleaching chemicals is contained in the second recovery installation.
Additional features of the invention are set forth below in an illustrative claim.
THE CLAIM
Claim 1 is illustrative of appellants’ invention and is reproduced below:
1. A process for producing bleached pulp comprising the steps of:
cooking a cellulosic material under alkaline conditions with a cooking
chemical to produce unbleached pulp;
recovering a filtrate containing a used cooking chemical in a first recovery
installation;
washing said unbleached pulp with acid;
delignifying said unbleached pulp in the presence of oxygen, whereby a
filtrate is produced containing released organic material;
bleaching said unbleached delignified pulp with a chlorine-free bleaching
chemical;
recovering a filtrate containing a used chlorine-free bleaching chemical and
said filtrate containing released organic material in a second recovery installation;
2
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