Visualization study on sedimentation of micron iron oxide particles

In this paper, a novel technique combined light-electronic microscopy and computer imaging trace was used for visualization of the sedimentation of micron iron oxide particles in a customized micro-reactor. Micron iron oxide particles were recovered from the cinder of sulfuric acid production by sedimentation separating and hydraulic rating. Effects of particle size, shape and surface roughness on the sedimentation velocity were investigated. For irregular-shape particles, the sedimentation velocity and the geometric parameters of the particles were measured by the imaging trace technique. A correction coefficient (c  ) was used to modify the Stokes equation. In this study, the relationship between the correction coefficient and the equivalent diameter (dpdp) was found to be linear: c=0.6272−0.0298dpc=0.6272−0.0298dp, for iron oxide particles with equivalent diameter 4–22 μm.

The iron oxide particles used in this study were cinders of the sulfuric acid production from ChuXing Co. Ltd., Hubei Province, China, by sedimentation separating and hydraulic rating. Added some water in a micro-reactor and then dispersed a small amount of iron oxide particles (the solid to liquid ratio is 0.01%, by weight) into the reactor. The optical micrograph of the particles prior to suspension into the liquid is shown in the figure.Figure optionsDownload as PowerPoint slide