Patent ID: 8016935

Claim:
An anticorrosion ferrite-based pigment for use in a paint to coat a substrate, the pigment being derived from a hydrometallurgical purification process of EAF dust, said EAF dust being generated: in an electric arc furnace or the like for producing carbon steel by processing source materials chosen from the group comprising scrap metals, direct reduced iron and pre-reduced hematite, and using a CaO-rich slag; and from a condensation reaction of metal vapors of Fe, of Zn and of metals chosen from the group consisting of Mn, Mg, Si and Al, and suspended CaO-based particles and oxygen; the pigment comprising: condensed metal oxides, comprising a plurality of different ferrites of the general formula MOFe 2 O 3 , wherein M comprises Zn, Fe, Mn, Mg and complexes thereof for the different ferrites, and having ferrite or ferrite-like structures substantially preserved from the EAF dust, and forming aggregates of said ferrite or ferrite-like structures; CaO entrapped by the ferrite or ferrite-like structures and being at least partially available to react with humid air and/or water to protect the substrate against corrosion; and from about 0.5% to about 20% by weight calcium.