Abstract: A process for the preparation of chromium(III) oxide by decomposing hydrated ammonium dichromate at elevated temperatures, an apparatus for carrying out this process and the use of the chromium(III) oxide thus prepared as a starting material for the synthesis of chromium dioxide.

Abstract: In a process for the preparation of 1-amino-2-phenoxy-4-hydroxyanthraquinone by reacting 1-amino-2-halogeno-4-hydroxyanthraquinone with a phenol in an alkaline aqueous medium at an elevated temperature, the improvement that 1-amino-2-chloro-4-hydroxyanthraquinone is reacted in aqueous suspension, at a pH of from 9 to 13 and at from 120.degree. to 150.degree. C., with the phenol in the presence of(a) ammonium salts N.sup..sym. (R).sub.4 A.sup..crclbar., wherein one or more R's are linear or branched C.sub.4 -C.sub.20 -alkyl or C.sub.7 -C.sub.10 -phenylalkyl and the remaining R or R's may also be phenyl or N.sup..sym. (R).sub.3 may be pyridinium, and A.sup..crclbar. is one equivalent of an anion, of(b) ethylene oxide/propylene oxide block copolymers or of(c) oxyethylation products of alkylphenols, of alkenylamines, of alkylamines or of alkanols. A very pure product is obtained, in high yield.