Patent ID: 8574450

Claim:
A process for preparing goethite, maghemite or lepidocrocite, comprising the steps of mixing a carboxylic acid selected from the group consisting of formic acid, acetic acid, glycolic acid, oxalic acid, trichloro-, dichloro- and chloroacetic acids, bromoacetic acid, iodoacetic acid, pyruvic acid, malonic acid and propionic acid with deionized water, adding microspheroidal iron having an average particle size of no more than 250 microns under a nitrogen or inert gas atmosphere at 50° C. to 70° C. to form a ferrous carboxylate in a solution having a moles acid to gram-atom iron ratio of 0.03 to 1.5 and a water/iron weight ratio from 1 to 20, substituting the nitrogen atmosphere or inert gas with an oxygen atmosphere or another oxidizing agent, and recovering the iron oxides of goethite, maghemite or lepidocrocite, said iron oxides having a specific surface area of 1-300 m 2 /g and being free of alkali and/or alkaline earth ions and/or ammonium ions and of sulfate and chloride ions.