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.

Date of Patent:
Jun. 17, 2025

Filed:

Feb. 13, 2020
Applicants:

Metsä Fibre Oy, Metsä, FI;

Andritz Oy, Helsinki, FI;

Inventors:

Ari Poukka, Metsä, FI;

Veli-Pekka Tervola, Helsinki, FI;

Assignees:

Metsä Fibre Oy, Metsä, FI;

[object Object];

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
D21C 11/00 (2006.01); D21C 9/14 (2006.01);
U.S. Cl.
CPC ...
D21C 11/0078 (2013.01); D21C 9/142 (2013.01); D21C 11/0057 (2013.01);
Abstract

According to an example aspect of the present invention, there is provided a method of replacing with sodium make-up chemicals sodium losses caused by outflows in a pulp mill which employs a kraft process for producing cellulosic pulp, wherein the pulp mill includes a unit for conversion of sulphurous compounds, which is fed with sulphurous substances of the kraft process to convert said sulphurous substances into oxidized sulphurous compounds, said method comprising using sodium sulphate possibly together with other sodium salts as the main make-up chemical, to achieve an essentially sodium hydroxide free feed of sodium make-up chemicals, and at least a part of the sulphur contained in the sodium sulphate make-up chemical being used for producing oxidized sulphurous compounds in said unit for conversion of sulphurous compounds.


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