Patent ID: 9539563
Date: 2017-01-10
CPC Classifications: B01J,C10G

Claim:
1. A method for the preparation of spherical core-shell particles, comprising the successive steps of: (a) preparing an aqueous solution comprising a ferric salt, at a temperature of less than 50° C.; (b) adding at least one base to said aqueous solution, so as to obtain a suspension of iron oxide particles having a pH value of from 10 to 14; (c) washing the suspension; (d) adding a strong acid to the washed suspension to peptize the washed suspension; (e) reacting at least one base with said peptized suspension, until the pH reaches a value from 10 to 14, at a temperature of from 50 to 95° C.; (f) adding a cobalt salt to the heated suspension in order to obtain spherical particles having a core of iron oxide and a shell comprising cobalt oxide.