METHOD FOR PRODUCING IRON OXIDE PIGMENT Russian patent published in 2018 - IPC C09C1/24 C09C3/04 

FIELD: technological processes.

SUBSTANCE: invention relates to a method for producing iron oxide pigments suitable for coloring materials in various fields of engineering. Method comprises mixing a pyrite cinder containing 46 % Fe₂O₃ and 24 % FeO, with ammonium chloride, its chlorination at 200–300 °C, leaching soluble metal chlorides at 60–90 °C, isolation by cementation of the copper powder, precipitation and separation by filtration of iron (III) hydroxide, its thermal oxidation by calcination at 300–1,000 °C. Leaching and filtration processes are conducted under the influence of ultrasound at a frequency of 22 kHz and a power density of 0.5–1.0 W⋅cm^-3.

EFFECT: invention provides for accelerating the production of iron oxide pigments from a pyrite cinder of a wide color range with an iron oxide content ≥98½ %.

1 cl, 8 ex