A process 1, characterized in that the iron oxides to be coated are γ Fe2 O3, {TAIL ~ Fe3 O4} or a bertholoid compound having {HEAD ~ an FeO content} of from 0 to 30% 
A process 1 , characterized in that the iron oxides to be coated are γ Fe2 O3 , { TAIL ~ Fe3 O4 } or a bertholoid compound having { HEAD ~ an FeO content } of from 0 to 30 %
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH