EP 0313114 B1 19910502 - PROCESS FOR OBTAINING PHOSPHATE COATINGS
Title (en)
PROCESS FOR OBTAINING PHOSPHATE COATINGS
Publication
Application
Priority
DE 3735538 A 19871021
Abstract (en)
[origin: EP0313114A1] In a process for obtaining phosphate coatings on metal surfaces consisting at least partially of iron or steel by means of phosphating solutions, which contain layer-forming cations and are operated on the iron side, wherein the content of iron (II) ions is limited by oxidation with oxygen-containing gases and precipitation of iron phosphate, the oxidation is carried out, in order to accelerate the oxidation of the iron(II) ions, at a temperature of at most 50 DEG C in the presence of microorganisms which oxidise iron(II), especially of Thiobacillus species, such as the strain Thiobacillus ferrooxidans. It is particularly advantageous here to branch a part stream of the phosphating solution off from the phosphating vessel and to carry out the oxidation and iron phosphate separation in a zone divided off from the phosphating zone, in particular in a column provided with packing, charged with oxygen-containing gas from below and operated with upward flow.
IPC 1-7
IPC 8 full level
C23C 22/07 (2006.01); C23C 22/10 (2006.01); C23C 22/73 (2006.01)
CPC (source: EP)
C23C 22/10 (2013.01); C23C 22/73 (2013.01)
Designated contracting state (EPC)
DE
DOCDB simple family (publication)
EP 0313114 A1 19890426; EP 0313114 B1 19910502; DE 3735538 A1 19890503; DE 3862635 D1 19910606; JP H01152281 A 19890614
DOCDB simple family (application)
EP 88201763 A 19880818; DE 3735538 A 19871021; DE 3862635 T 19880818; JP 26169288 A 19881019