Claims
- 1. A process for the preparation of very pure, aqueous hydroxylamine solution by concentrating and purifying an aqueous hydroxylamine solution, wherein the concentration is carried out in a column, hydroxylamine-containing vapors are removed via a side take-off in the bottom of the column and very pure hydroxylamine is obtained by condensing the vapors.
- 2. A process as defined in claim 1, wherein the hydroxylamine solution intended for concentration and purification is obtained by
- a) treating a hydroxylammonium salt with a suitable base in water and,
- b) separating the solution obtained, if necessary after removal of insoluble components, into an aqueous hydroxylamine fraction and a salt fraction by treatment with water or steam at <80.degree. C.
- 3. A process as defined in claim 1, wherein the condensation of the very pure hydroxylamine solution is effected by introducing the hydroxylamine-containing vapors, removed via the side take-off, below a condenser and above an evaporator and partially evaporating again in the evaporator the hydroxylamine solution condensed in the condenser, so that a more highly concentrated very pure hydroxylamine solution is obtained.
- 4. A process as defined in claim 1, wherein the hydroxylamine-containing vapors taken off via a side take-off in the bottom of the column are passed into a side column and very pure hydroxylamine solution is obtained at the bottom of the side column.
- 5. A process as defined in claim 1, wherein the side take-off is connected on the gas side to the concentration column.
- 6. A process as defined in claim 1, wherein materials free of metal ions and resistant to hydroxylamine are used for the parts of the side take-off plant.
Priority Claims (1)
Number |
Date |
Country |
Kind |
197 25 851 |
Jun 1997 |
DEX |
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Parent Case Info
This application is a 371 of PCT/EP98/03714 filed Jun. 18, 1998.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
102e Date |
371c Date |
PCT/EP98/03714 |
6/18/1998 |
|
|
12/8/1999 |
12/8/1999 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO98/57886 |
12/23/1998 |
|
|
US Referenced Citations (8)
Foreign Referenced Citations (6)
Number |
Date |
Country |
001787 |
May 1979 |
EPX |
108294 |
May 1984 |
EPX |
237052 |
Sep 1987 |
EPX |
3528463 |
Feb 1987 |
DEX |
9722551 |
Jun 1997 |
WOX |
9722550 |
Jun 1997 |
WOX |
Non-Patent Literature Citations (2)
Entry |
Z. Anorg. Chem., 288, 1956, 28-35. |
Roth-Weller: Gef. Chem. Reak., Stoffinformmation Hydroxylamin, p. 3, 1984. |