GB791536A - Improvements in the purification of melamine - Google Patents
Improvements in the purification of melamineInfo
- Publication number
- GB791536A GB791536A GB1531/56A GB153156A GB791536A GB 791536 A GB791536 A GB 791536A GB 1531/56 A GB1531/56 A GB 1531/56A GB 153156 A GB153156 A GB 153156A GB 791536 A GB791536 A GB 791536A
- Authority
- GB
- United Kingdom
- Prior art keywords
- melamine
- alkali
- hydroxide solution
- normal
- alkali hydroxide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D251/00—Heterocyclic compounds containing 1,3,5-triazine rings
- C07D251/02—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings
- C07D251/12—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members
- C07D251/26—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members with only hetero atoms directly attached to ring carbon atoms
- C07D251/40—Nitrogen atoms
- C07D251/54—Three nitrogen atoms
Abstract
Melamine is purified by treating crude melamine with an excess of alkali hydroxide solution (preferably potassium or sodium hydroxide solution) with reference to the content of alkali-soluble substances, at a pH value in excess of 13 and at a temperature sufficiently low for the avoidance of melamine decomposition (preferably at room temperature), if desired washing with at least 0.1 normal alkali hydroxide solution until there is complete freedom from ammelide, separating the melamine and washing it free from alkali, and, if desired, dissolving the melamine in formaldehyde solution and filtering off insoluble impurities. Preferably 1.4 to 2.0 mols. of alkali hydroxide solution are used for each mol. of alkali-soluble impurities. The alkali hydroxide solution used is also preferably stronger than 1.0 normal (e.g. 10 normal) and only sufficient water is added to render the resulting mixture capable of being stirred. Crude melamine prepared from urea and having a high iron content can be freed from a large part of such iron by separating the iron compounds which become enriched at the surface of the melamine-water mixture prior to the treatment with alkali.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE791536X | 1955-01-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB791536A true GB791536A (en) | 1958-03-05 |
Family
ID=6704389
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1531/56A Expired GB791536A (en) | 1955-01-26 | 1956-01-17 | Improvements in the purification of melamine |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB791536A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2227292A (en) * | 1989-01-18 | 1990-07-25 | Usui Kokusai Sangyo Kk | Pipe connectors |
-
1956
- 1956-01-17 GB GB1531/56A patent/GB791536A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2227292A (en) * | 1989-01-18 | 1990-07-25 | Usui Kokusai Sangyo Kk | Pipe connectors |
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