Process for preparation of micaceous iron oxide
AssigneeCentral Glass Company, Limited
InventorsMasanori Hayakawa, Satoshi Nishimura
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Abstract
High purity hexagonal plate-like .alpha.-Fe.sub.2 O.sub.3, commonly called micaceous iron oxide, is prepared by a hydrothermal treatment of either magnetite or an iron ore, or an iron oxide, of which principal component is magnetite together with an oxidizer in an aqueous alkali solution. Main advantage of this process is a great decrease in the consumption of alkali. Pure magnetite for use in this process can be prepared economically by a hydrothermal treatment of an iron ore, or an oxide, of which principal component is an oxide of trivalent iron in an aqueous alkali solution together with a compound of divalent iron and/or metallic iron.
Claims22
A process of preparing hexagonal plate-like crystals of .alpha.-Fe.sub.2 O.sub.3, comprising mixing a first material of which a principal component thereof is magnetite, an aqueous alkali solution having an alkali concentration in the range of 1 to 20 N, and an oxidizer, in a closed vessel and hydrothermally treating the resultant mixture at a temperature of from about 100.degree. to 400.degree. C. for a time sufficient to effect formation of hexagonal plate-like crystals of .alpha.-Fe.sub.2 O.sub.3.
Dependencies are inferred from the claim text.