US 2003/0213570 A1 · Process for producing very low COD unbleached pulp

Abstract

A pulp product that has a low COD is comprised of an unbleached pulp that is soaked and washed in alkaline water for a sufficient time so that the COD after soaking and washing is less than or equal to 3.0 kg/1000 kg of dry pulp. The pulp is produced by repetitively soaking and washing an unbleached pulp in alkaline water that is never allowed to drop below pH 7.0. The pulp is soaked and washed for a total of at least 400 minutes at an elevated temperature to produce the pulp product that has a low COD.

Claims14

Dependent claims

A process for making a low COD pulp, comprising:

(a) repetitively soaking and washing unbleached pulp in water that is maintained at alkaline conditions such that said pulp is soaked for a total of at least 400 minutes at an elevated temperature to produce a pulp product that has a COD of less than or equal to 3.0 kg per 1000 kg;
and
(b) dewatering said pulp.

Dependencies are inferred from the claim text.

Facts

Application

10/209,446Filed 30 Jul 2002

Published

20 Nov 2003

Term ends

Not estimatedThe source records don’t support an estimate.

Classification7 codes

D21C 9/02
After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking…:…
C04B 18/241
Vegetable refuse, e.g. rice husks, maize-ear refuse; Cellulosic materials, e.g. paper , cork: paper, e.g. waste paper; Paper pulp
D21C 9/083
Removal of fats, resins, pitch or waxes; Chemical or physical purification, i.e. refining, of crude cellulose by removing non-cellulosic…: with…
Y02W 30/91
Reuse, recycling or recovery technologies: use of waste materials as fillers for mortars or concrete

Process for producing very low COD unbleached pulp

Life of this patent

Process for producing very low COD unbleached pulp

Life of this patent

Abstract

Claims14