High-magnesium ammonium polyphosphate solutions
US3933459A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 11, 1974 |
| Grant date | Jan 20, 1976 |
| Priority date | — |
| Expiry date | Oct 11, 1994 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC05B1/06
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A stable ammonium polyphosphate fertilizer solution having a relatively high amount of magnesium is prepared by mixing aqueous ammonia with wet-process superphosphoric acid in a reaction zone to give a P.sub.2 O.sub.5 /N weight ratio within the range 3.6-4.0. The temperature of the reaction mixture is preferably maintained at about 50.degree.-70.degree.C. but the product solution should be cooled to about 25.degree.-35.degree.C. prior to storage. The product solution shows relatively low corrosion toward carbon steel storage tanks; however, to further reduce corrosion, the solution is preferably stored under a layer of liquid paraffin hydrocarbons.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.