What is sulfuric acid + iron oxide

Iron (III) oxide is obtained by grinding red iron ore and a subsequent cleaning process. It is also obtained by glowing iron (III) nitrate or iron sulfate and by roasting pyrite.
Iron (III) oxide is of great importance for the production of pig iron in blast furnaces. As iron oxide red, it is used as a permanent pigment for anti-rust paints, paints and for coloring ceramics. Thermit mixtures for thermite welding also contain iron (III) oxide. It is approved as a food additive E 172 and is suitable for coloring sausage products. Due to its magnetizability, iron (III) oxide is suitable as a carrier material on audio tapes, which are still used today in professional music productions.

Iron oxide pigments are available in different colors.

Further information and media
Demonstrations: reductions (with thermite test)
Iron oxide pigments and red earths for painting
Information about thermite welding
Information on the blast furnace process
Copy template for the blast furnace
The mineral hematite