Process for the thermal treatment of iron oxides in a circulating fluid bed,申请号EP19950119764-传众专利搜索

Process for the thermal treatment of iron oxides in a circulating fluid bed

申请公布号：EP0719731(B1)

申请号：EP19950119764

申请日期：1995.12.14

申请公布日期：1998.03.18

申请人：

BAYER AG

发明人：KREKEL, JOERG, DR.;KOEHLER, BERNDT-ULLRICH, DR.;BRUNN, HORST, DR.

分类号：C01G49/02;C01G49/06;C01G49/08;C04B18/02;C09C1/22;C09C1/24;C09D17/00;(IPC1-7):C01G49/08

主分类号：C01G49/02

摘要：<p>Prepn. of Fe oxide pigments of the ( alpha -, gamma -) Fe2O3 and Fe3O4 gp. comprises using a corresp. starting suspension, in which the prim. particles have an average dia. of at most 10 mu m, which is obtd. by: (1) (a) reacting Fe salt solns. with alkaline cpds. and oxidn. (pptn. process); (b) oxidn. of Fe with O cpds. (Penniman process); (c) oxidn. with nitrobenzene (nitrobenzene redn. process); (d) roasting Fe salts (copper as process) and making into a paste with water or; (e) sepg. and working up by-prods. or waste (sewage pastes) based on Fe/Fe cpds. and oxygen; (2) opt. washing; and (3) thermal treatment. The novel features are that the material obtd. by process (a-e) is: (4) agglomerated to an average particle size of 0.05-10 mm, without added binder; and (5) subjected to thermal treatment in heated appts., in which it is fluidised with an upward gas stream; then (6) the mixt. is sepd. into gas and solid components in a second zone, pt. of the solid stream is discharged and the remaining material is recycled to the heated appts.</p>