EP 2649010 A1 20131016 - METHOD FOR PRODUCING CHROMIUM (III) OXIDE
Title (en)
METHOD FOR PRODUCING CHROMIUM (III) OXIDE
Title (de)
VERFAHREN ZUR HERSTELLUNG VON CHROM(III)-OXID
Title (fr)
PROCÉDÉ DE FABRICATION D'OXYDE DE CHROME (III)
Publication
Application
Priority
- EP 10194157 A 20101208
- EP 11180086 A 20110905
- EP 2011071997 W 20111207
- EP 11791295 A 20111207
Abstract (en)
[origin: WO2012076564A1] Process for preparing chromium(III) oxide, which comprises the steps: a) reaction of sodium monochromate with gaseous ammonia, more particularly at a temperature of from 200 to 800°C, b) hydrolysis of the reaction product obtained according to step a), where the pH of the water for the hydrolysis is reduced by means of an acid before the hydrolysis or that of the alkaline mother liquor is reduced by means of an acid during or after the hydrolysis to a value of from 4 to 11, preferably from 5 to 10, c) isolation of the hydrolysis product precipitated according to step b), preferably at a pH of from 4 to 11, more particularly from 5 to 10, and optionally washing and optionally drying, and d) calcination of the hydrolysis product obtained according to step c) at a temperature of from 700 to 1400°C, more particularly from 800 to 1300°C.
IPC 8 full level
C01G 37/00 (2006.01); C01G 37/033 (2006.01); C09C 1/34 (2006.01)
CPC (source: EP US)
C01G 37/00 (2013.01 - EP US); C01G 37/033 (2013.01 - EP US); C09C 1/346 (2013.01 - EP US); C01P 2006/80 (2013.01 - EP US)
Citation (search report)
See references of WO 2012076564A1
Designated contracting state (EPC)
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
DOCDB simple family (publication)
WO 2012076564 A1 20120614; AR 084183 A1 20130424; CN 103249677 A 20130814; CN 103249677 B 20160817; EP 2649010 A1 20131016; RU 2013130866 A 20150410; RU 2591245 C2 20160720; US 2014105812 A1 20140417; US 9580333 B2 20170228; ZA 201304161 B 20140226
DOCDB simple family (application)
EP 2011071997 W 20111207; AR P110104569 A 20111206; CN 201180059196 A 20111207; EP 11791295 A 20111207; RU 2013130866 A 20111207; US 201113991516 A 20111207; ZA 201304161 A 20130606