The invention discloses a coated
iron oxide black
pigment and a preparation method thereof, and belongs to the technical field of
iron oxide black
pigment preparation. The method comprises the following steps: (1) adding an
iron oxide black
filter cake and water into a reaction container, and uniformly stirring; (2) preparing an additive into an
aqueous solution, adding the
aqueous solution into areaction container, and mechanically ball-milling and dispersing to obtain an
iron oxide black dispersion liquid; (3) heating the
iron oxide black dispersion liquid, adding a soluble aluminum salt under a
nitrogen atmosphere condition, heating, and controlling the temperature for
coating; and (4) carrying out
centrifugal separation,
drying the
filter material, and calcining to obtain the
iron oxide black pigment coated with the aluminum layer. Air is isolated in the
coating process, and
black iron oxide is prevented from being oxidized in the
coating process; the dispersion performance of theiron
oxide black is improved by adopting the additive and a mechanical ball milling mode, and more stable dispersion liquid is obtained. The pigment is uniform in particle size, and the outer layer is coated with a layer of compact aluminum film, so that the pigment cannot be oxidized even at high temperature, and the performance of the pigment is more stable.