Patent · US Expired

Process for the brightening of sodium hydrogensulfate

US7067094B2 · kind B2 · utility

0Cited by

6References

4Claims

0Family size

Assignee

Grillo-Werke AG · DE

Inventors

Klaus Driemel · Duisburg, DE
Ingo Biertümpel · Duisburg, DE
Horst Kirsch · Villmar, DE

Key dates

Filing date	Aug 30, 2004
Grant date	Jun 27, 2006
Priority date	—
Expiry date	Aug 30, 2024

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC01D5/02
WIPO fieldMaterials, metallurgy
WIPO sectorChemistry

Abstract

The process for the brightening of continuously produced sodium hydrogensulfate obtained in the reaction of sodium chloride and concentrated sulfuric acid in molten sodium hydrogensulfate in a circulation reactor, wherein evolved hydrogen chloride and heating gases generated by an immersion burner are withdrawn at various sites and seed crystals are added for a faster conversion of initially formed metastable phases, is that from 0.01 to 0.05% by weight of aluminium oxide and/or from 0.5 to 1.5% by weight of magnesium oxide and/or magnesium sulfate and, optionally, additionally calcium sulfate are added as seed crystals.

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