Method for manufacturing lepidocrocite

Abstract

Lepidocrocite (.gamma.-FeOOH) with an large specific surface area and a uniform particle size is provided by a method comprising preparing a suspension of ferrous hydroxide at a pH of 6.5 to 7.5 by adding a ferrous salt solution with an alkali solution in an amount of 0.4 to 0.7 times the theoretical amount for converting all the ferrous salt to ferrous hydroxide, blowing an oxygen-containing gas into the suspension to form a seed crystal of .gamma.-FeOOH, completing the generation reaction of .gamma.-FeOOH by blowing an oxygen-containing gas into the suspension while adding an alkali solution to keep the pH of the suspension within a range of 3 to 5, in which an Si concentration of the suspensions for seed reaction and for generation reaction of .gamma.-FeOOH is controlled to be within 5 to 30 ppm.

Dependencies are inferred from the claim text.