Title:
METHOD FOR PURIFYING SOLUTIONS CONTAINING CYANAMIDE
Document Type and Number:
WIPO Patent Application WO2003089372
Kind Code:
A3
Abstract:
The invention relates to a method for purifying solutions containing cyanamide, according to which the parent solution is subjected to a membrane filtration at temperatures of between -20 and +80 DEG C, whereby the separation membrane has an MWCO value of between 80 Da and 60 kDa and the parent solution is subjected to a pressure of between 2.5 and 60 bar. In said method, which preferably operates according to the feed-and-bleed principle and whereby the solution retained by the membrane is subjected to a circulatory flow in front of the membrane, parent solutions having a cyanamide content of between 5 and 60 wt. % are used. This permits over 80 % of compounds containing in particular calcium, iron, nickel and silicon to be eliminated from the solutions used.
Inventors:
GUETHNER THOMAS (DE)
FASENACHT JOHANN (DE)
FASENACHT JOHANN (DE)
Application Number:
PCT/EP2003/004086
Publication Date:
February 05, 2004
Filing Date:
April 16, 2003
Export Citation:
Assignee:
DEGUSSA (DE)
GUETHNER THOMAS (DE)
FASENACHT JOHANN (DE)
GUETHNER THOMAS (DE)
FASENACHT JOHANN (DE)
International Classes:
B01D61/02; B01D61/14; B01D71/64; C01B21/12; C01C3/16; (IPC1-7): C01C3/16
Foreign References:
| US5843318A | 1998-12-01 | |||
| US3370922A | 1968-02-27 |
Other References:
DATABASE CA [online] CHEMICAL ABSTRACTS SERVICE, COLUMBUS, OHIO, US; GOL'DBERG, N. A. ET AL: "Purification of cyanamide solutions from calcium(II) by using cation-exchange agents", XP002254540, retrieved from STN Database accession no. 66:49757 CA
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