Title:
A PROCESS OF RECOVERING ALKALI FROM BLACK LIQUOR OF PAPERMAKING
Document Type and Number:
WIPO Patent Application WO/2003/066961
Kind Code:
A1
Abstract:
The present invention relates to a process of recovering alkali from black liquor of papermaking. The improvement of the process is adding two steps of a green liquor treatment and a lime cleaning to the traditional process of the alkali recovery, changing processing conditions, and carrying out two causticization plants, thereby eliminates formation of a white liquor mud and need not to process the mud. By this process, it can also produce following product: 50wt% or more of calcium carbonate having particle size of 2µm or less for use in coated paper; 90wt% or more of calcium carbonate having average particle size of less than 1µm. the present invention is suitable to treat the black liquor of alkali process.
Inventors:
AI TIANZHAO (CN)
DONG XUEZHI (CN)
AI DONG (CN)
DONG XUEZHI (CN)
AI DONG (CN)
Application Number:
PCT/CN2002/000290
Publication Date:
August 14, 2003
Filing Date:
April 25, 2002
Export Citation:
Assignee:
AI TIANZHAO (CN)
DONG XUEZHI (CN)
AI DONG (CN)
DONG XUEZHI (CN)
AI DONG (CN)
International Classes:
C01D1/20; C01F11/18; D21C11/04; (IPC1-7): D21C11/04; D21C11/10; D21C11/12; C01F11/18; C01D1/20
Foreign References:
| CN1239166A | 1999-12-22 | |||
| CN1045567A | 1990-09-26 | |||
| US5628875A | 1997-05-13 |
Other References:
See also references of EP 1482087A4
Attorney, Agent or Firm:
CCPIT PATENT AND TRADEMARK LAW OFFICE (2 Fuchengmenwai Sreet, Beijing 7, CN)
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