| 摘要 |
<p>The invention relates to iron-silicon-oxide particles in spherical and/or spheroidal form, having two sections, wherein one section substantially comprises amorphous silicon dioxide and the other section substantially comprises iron oxide, characterized in that a) the ratio of silicon dioxide or iron oxide, calculated as Fe2O3, equals 10 to 90 wt % and b) the iron oxide ratio comprises 5 to 75 wt % of maghemite, 20 to 90 wt % of magnetite, 0 to 15 wt % of hematite, 0 to 5 wt % of beta- Fe2O3.</p> |
