杯式连续沉淀器中草酸亚铁的沉淀工艺

采用着色法研究了杯式连续沉淀器中流场形状与性质，并采用加入颗粒、即时沉淀反应生成颗粒两种方式考察了沉淀颗粒在中心涡流区域的分布与扩散情况。在26 ℃时，采用杯式连续沉淀器研究了料液的加料方式、搅拌速率、表观反应时间等因素对生成的草酸亚铁沉淀颗粒粒径分布和平均粒径、对连续沉淀器和搅拌桨表面颗粒粘结的影响。当草酸料液与硫酸亚铁料液均从杯式连续沉淀器中心涡流区域加入时，可以有效避免沉淀器内壁产生颗粒粘附、结块现象，且所生成的颗粒平均粒径较大，其中生成的粒径为2～5 μm和小于10 μm的颗粒所占比例较小。当搅拌速率在500～800 r/min时，提高搅拌转速不利于生成粒径为2～5 μm和小于10 μm的沉淀颗粒，而草酸亚铁连续沉淀反应的表观反应时间大于30.0 min时，沉淀颗粒的生长速率逐渐变缓。

Precipitation Technological Conditions of Ferrous Oxalatein in Cup Type Continuous Precipitation Reactor

The staining method was used to study the shape and properties of flow field in a cup continuous precipitation reactor. And the distribution and diffusion of precipitated particles in the central eddy region were investigated in two ways, namely, the addition of particles and the formation of particles by instant precipitation reaction. At 26 ℃, the effects of feeding method, stirring speed and apparent reaction time on the particle size distribution and average particle size of the precipitated oxalate particles, surface particles attachment of reactor and stirred paddle were investigated in a cup type continuous precipitation reactor. When both oxalic acid and ferrous sulfate solution are added from the central eddy current region in a cup precipitator, the particle bonding and agglomeration can be avoided in the inner wall of the reactor, and the average size of the particles is relatively large, in which the proportion of the particle size of 2.5 μm and <10 μm was relatively small. When the stirring rate is in the range of 500-800 r/min, increasing the stirring speed is unfavorable to the formation of precipitates with particle sizes of 2.5 μm and <10 μm. When the apparent time of the continuous precipitation reaction of ferrous oxalate is longer than 30.0 minutes, the growth rate of the precipitated particles gradually slows down.