Bucknam and Archer
Process for the preparation of acicular .alpha.-iron oxide hydrate
 A process for the preparation of acicular .alpha.-iron oxide hydrate which comprises oxidizing a slurry of ferrous hydroxide having an excessive alkali concentration of 1.0 mol/l or above with an oxygen-containing gas, interrupting oxidation, adding an excessive quantity of an aqueous solution of a salt of aluminate, homogenizing and stirring the resulting mixture, again oxidizing it with an oxygen-containing gas to obtain a slurry containing free aluminate ion and .alpha.-iron oxide hydrate, homogenizing and stirring the slurry, then neutralizing and aging it, and washing and drying it. 
Mitsui Mining & Smelting Co., Ltd.
C C C C G C
C01G C01P C01P C01P G11B C01P
inventional additional additional additional inventional additional
Yoshinobu Makoto Hisasige Isshi Masahide Tadayosi
Oka Miyaji Ito Hisaoka Shouji Saruwatari