Patent · US Expired

Method of recycling phosphating sludges

US5350517A · kind A · utility

0Cited by

2References

20Claims

0Family size

Assignee

Henkel Kommanditgesellschaft auf Aktien · DE

Inventors

Willi Buchmeier · Goldkronach, DE
Wolf-Achim Roland · Solingen, DE

Key dates

Filing date	Apr 19, 1993
Grant date	Sep 27, 1994
Priority date	—
Expiry date	Apr 19, 2013

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY02P10/20
WIPO fieldSurface technology, coating
WIPO sectorChemistry

Abstract

Described is a method of recycling the sludge which arises during the zinc phosphating of steel surfaces. The sludge is preferably digested with nitric acid, the iron selectively extracted from the digested solution with liquid/liquid extraction and the extract thus obtained reused in the preparation of zinc phosphating solution. The preferred extraction solvent is a solution of the monoester of 2-ethylhexyl alcohol with phosphoric acid in kerosene.

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