EP 0144868 B1 19890125 - PROCESS FOR MANUFACTURING FINE METALLIC CHROMIUM POWDER WITH A LOW OXYGEN CONTENT
Title (en)
PROCESS FOR MANUFACTURING FINE METALLIC CHROMIUM POWDER WITH A LOW OXYGEN CONTENT
Publication
Application
Priority
DE 3343989 A 19831206
Abstract (en)
[origin: US4767454A] For preparing a chromium metal powder lacking in oxygen and having an average particle size not greater than 20 mu m, a mixture of chromium oxide and calcium oxide, in a molar ratio of 1:0.5 to 1:2, is calcined initially at temperatures of 650 DEG to 1,200 DEG C. with access of oxygen up to a weight increase of 1 to 6 g per mole of chromium oxide, the calcined product is comminuted to a particle size not greater than 100 mu m and the product so obtained is reduced calciothermally. The calcium oxide can be replaced wholly or partially by calcium carbonate.
IPC 1-7
IPC 8 full level
B22F 9/20 (2006.01); C22B 5/04 (2006.01); C22B 34/32 (2006.01)
CPC (source: EP US)
B22F 9/20 (2013.01 - EP US); C22B 5/04 (2013.01 - EP US); C22B 34/32 (2013.01 - EP US)
Designated contracting state (EPC)
DE FR GB
DOCDB simple family (publication)
DE 3343989 C1 19841213; DE 3476347 D1 19890302; EP 0144868 A2 19850619; EP 0144868 A3 19870916; EP 0144868 B1 19890125; US 4767454 A 19880830
DOCDB simple family (application)
DE 3343989 A 19831206; DE 3476347 T 19841123; EP 84114148 A 19841123; US 1138587 A 19870205