Urea passivation technique and new product passivated urea, to make urea or urea-based compound universally blendable
US9487452B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 28, 2013 |
| Grant date | Nov 8, 2016 |
| Priority date | — |
| Expiry date | Aug 28, 2033 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C273/14
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The invention concerns a method of producing passivated urea or urea based compounds for fertilizer blends wherein the urea particles are treated with a mineral acid that reacts with urea and creates a grasping layer. Thereafter a solid base in powder form is added in excess to the particles to coat the acidified particle surface. The invention also concerns a fertilizer blend comprising the passivated urea or urea based compounds with one or more of AN or AN-based compound, NS products, superphosphates, and more generally with a priori most compounds that urea is susceptible to react with when in direct contact. A safe blend comprises more than 40 weight % of the passivated urea.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.