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. 03, 2015
Filed:
Nov. 11, 2011
Martin Wimby, Torslanda, SE;
Mattias Svensson, Örnsköldsvik, SE;
Henrik Wallmo, Alingsås, SE;
Fredrik Öhman, Gävle, SE;
Per Tomani, Huddinge, SE;
Lars-erik Åkerlund, Sollentuna, SE;
Martin Wimby, Torslanda, SE;
Mattias Svensson, Örnsköldsvik, SE;
Henrik Wallmo, Alingsås, SE;
Fredrik Öhman, Gävle, SE;
Per Tomani, Huddinge, SE;
Lars-Erik Åkerlund, Sollentuna, SE;
Valmet AB, Sundsvall, SE;
Abstract
The method is for separation of lignin from original black liquor (BL) and has the following phases in sequence. A first precipitation phase (PR) for precipitation of lignin by a first acidification of the original black liquor by adding a first acid or mixture of acids (G) followed by a first storage phase wherein precipitated lignin particles are allowed to increase in size, followed by a second precipitation phase (PR) for precipitation of lignin by a further acidification of the original black liquor by adding a second acid or mixture of acids (G). By retaining the acidified black liquor for at least 25 minutes in the storage phase are the precipitated lignin particles allowed to grow in size and the filterability is improved considerably.