Patent No. U.S. 6,503,315
Bayer Aktiengesellschaft has obtained a patent for a process for preparing iron oxide red pigments. The process comprises forming a suspension of haematite nuclei through a reaction between dilute nitric acid and elemental iron at above 90˚C, converting the suspension of haematite nuclei to a suspension of haematite pigment and optionally recovering the pigment as a solid.