The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 09, 1976
Filed:
Apr. 22, 1975
Bengt Gunnar Broddevall, Skoghall, SW;
Uddeholms Aktiebolag, Skoghall, SW;
Abstract
A process for decoloring an aqueous effluent from the bleaching of sulphate pulp with chlorine or chlorine containing compounds, said effluent containing dark colored lignin degradation products, said bleaching including at least one alkali extraction stage, comprises A. treating the aqueous effluent from at least one alkali extraction stage in the bleaching with at least one acid selected from the group consisting of sulphuric acid, sulphurous acid and hydrochloric acid until a precipitate forms, said precipitate consisting essentially of dark colored lignin degradation products and other organic material B. separating the treated aqueous effluent from the precipitate and C. contacting the treated aqueous effluent which has been separated from the precipitate with a phenolic resin which is activated by the acidic effluent, said activated resin binding the dark colored lignin degradation products and separating a decolored effluent from the loaded resin.