Patent · US Expired

Process for the recorvery of sulphuric acid in the production of titanium dioxide

US4988495A · kind A · utility

3Cited by

7References

3Claims

0Family size

Assignee

BAYER HEALTHCARE LLC · DE

Inventors

Gerhard Wiederhoft · Krefeld, DE
Eckhard Bayer · Krefeld, DE
Wolfgang Muller · Dortmund, DE
Gunter Lailach · Krefeld, DE

Key dates

Filing date	Dec 15, 1989
Grant date	Jan 29, 1991
Priority date	—
Expiry date	Dec 15, 2009

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC01P2006/60
WIPO fieldMaterials, metallurgy
WIPO sectorChemistry

Abstract

A process for the preparation of an improved quality TiO.sub.2 pigment by hydrolysis of titanyl sulphate, isolation of the hydrolysis product form the waste acid produced during the hydrolysis, washing of the hydrolysis product and calcination of the hydrolysis product to form the TiO.sub.2 pigment, wherein the hydrolysis of the titanyl sulphate is carried out using separately produced hydrolysis nuclei which have been produced by a reaction of titanium salts with alkaline reagents, and in which waste acid and/or wash liquid containing waste acid is added after at least 50% of the total duration of the hydrolysis process.

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