Abstract: A process for the decomposition of chrome ore by alkaline oxidation bymixing finely divided chrome ore with alkaline compounds,heating the mixture in an indirectly heated rotary kiln to between 800.degree. and 1,200.degree. C.,introducing oxygen or gases enriched with oxygen countercurrently to the mixture, whereinthe mixture of chrome ore and alkaline compound is divided into a large number of individual streams,each individual stream is fed into a separate indirectly heated rotary kiln,the large number of rotary kilns is combined in the form of a bank of kilns,the theoretical distance covered by the particles of the mixture through the rotary kiln is 5 to 30 m, andthe resulting average coverage of the inner surface of the rotary kiln is 1 to 5 kg of mixture/m.sup.2.