Patent · US Expired

Batch production of suspension fertilizers using lignosulfonate

US4932993A · kind A · utility

1Cited by
3References
14Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 7, 1988
Grant dateJun 12, 1990
Priority date
Expiry dateNov 7, 2008

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC05B7/00
  • WIPO fieldBasic materials chemistry
  • WIPO sectorChemistry

Abstract

In the production of suspension fertilizers the addition of an additive comprising lignosulfonate to the wet-process acid prior to the ammoniation step prevents severe thickening of the suspension during its formation, which severe thickening is normally associated with in situ mass crystallization of monoammonium phosphate and which mass crystallization results in (1) the total prevention of further ammoniation of said acid or, at the very least, extremely slow further ammoniation thereof, and/or (2) excessive ammonia losses. Also, addition of said lignosulfonate to the acid prevents the formation of metallic impurity gel-like compounds which cause extremely high viscosities, nonpourability, and complete destruction of fluidity.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.