METHOD FOR PREPARING INORGANIC PIGMENTS, RESULTING INORGANIC PIGMENTS, AND APPARATUS THEREFOR

摘要

PCT No. PCT/FR96/01202 Sec. 371 Date May 27, 1998 Sec. 102(e) Date May 27, 1998 PCT Filed Jul. 30, 1996 PCT Pub. No. WO97/06215 PCT Pub. Date Feb. 20, 1997A method for preparing inorganic pigments from steel mill dust, particularly electric steel mill dust, wherein (a) the dust is separated into a magnetic fraction and a non-magnetic fraction; (b) the non-magnetic fraction is subjected to a basic leaching reaction; (c) the resulting solid batch is rinsed until neutralized and then separated; (d) the resulting batch is calcined at 450-650 DEG C.; (e) the calcined batch is treated with sulfuric acid in the presence of a catalyst; (f) the inorganic pigments are recovered; and (g) the solutions from (c) and (e) are used to precipitate other pigments.