Patent · US Active

Dihydrate-hemihydrate process for producing phosphoric acid

US9371230B2 · kind B2 · utility

2Cited by

7References

10Claims

0Family size

Assignee

PRAYON TECHNOLOGIES · BE

Inventors

Antoine Hoxha · Neuville-en-Condroz, BE
Dorina Fati · Neuville-en-Condroz, BE

Key dates

Filing date	Jun 1, 2011
Grant date	Jun 21, 2016
Priority date	—
Expiry date	Jun 1, 2031

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC01B25/228
WIPO fieldMaterials, metallurgy
WIPO sectorChemistry

Abstract

A method for producing phosphoric acid, comprising attack in an aqueous medium of phosphated rock with sulfuric acid, with formation of a first dihydrate slurry suspended in an aqueous phase having a free P2O5 content between 38 and 50% and a free SO3 content of less than 0.5%, conversion of this first slurry by heating with recrystallization of the solubilized calcium sulfate giving rise to a second hemihydrate slurry, and separation in the second slurry between a production phosphoric acid and a hemihydrate cake, characterized in that it comprises during the attack, addition of a fluorine source in the first slurry in a content from 1% to 5% by weight of F relatively to the P2O5 contained in the phosphated rock.

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