Sedimentation separation is used in various industrial fields. In sedimentation, it is common to improve separation efficiency by adding chemicals such as flocculants to flocculate fine particles and thereby increase their sedimentation rate. However, the added chemicals remain in the separated and recovered solids(particles). Therefore, even if the recovered solids can be used for other purposes, the chemicals may prevent them from being reused as contaminant.

Therefore, we have proposed a method to accelerate sedimentation of fine particles in water by applying horizontal DC electric field without adding any chemicals. In previous studies, the mechanism of accelerated sedimentation of fine particles in water by applying horizontal DC electric field has not been fully clarified. In this study, we attempted to elucidate the mechanism by observing the accelerated sedimentation phenomenon when applying horizontal DC electric field to an aqueous slurry under various conditions, and by measuring pH and particle diameter before and after applying DC electric field.

As a result, we found that the phenomenon of accelerated particle sedimentation when applying a horizontal DC electric field to an aqueous slurry is caused by two main factors: “particle agglomeration” and “a mechanism similar to the Boycott effect, in which a particle-free region near one electrode formed by particle electrophoresis moves upward due to density flow generated by the horizontal density difference”. Furthermore ...