Patent · US Active

Method for producing phosphoric acid

US9255006B2 · kind B2 · utility

0Cited by

6References

12Claims

0Family size

Assignee

PRAYON TECHNOLOGIES · BE

Inventors

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

Key dates

Filing date	Dec 2, 2010
Grant date	Feb 9, 2016
Priority date	—
Expiry date	Jun 29, 2031

Classification

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

Abstract

The invention relates to a method for producing phosphoric acid, including: attacking phosphate rock by means of sulfuric acid between 70° and 90° C. with formation of a first calcium sulfate dihydrate crystal slurry, the aqueous acid phase of said slurry having free P2O5 content between 38 and 50 wt % and free SO3 content that is less than 0.5 wt % and greater than 0.05 wt %; converting said first slurry by means of heating at a temperature greater than 90° C., thus giving rise to a second slurry formed of calcium sulfate hemihydrate crystals; and, within the second slurry, separating a produced phosphoric acid, having a free SO3 content that is less than 2%, and a calcium sulfate hemihydrate filter cake.

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