Development of a novel slurry condensation method by applying dispersant instead of flocculant

A novel filtration technique has been developed by adding the dispersant instead of the flocculant used in conventional solid–liquid separation technique. Slurries were prepared by controlling the pH values in order to control the dispersion and flocculation degree of particles. The prepared slurries were condensed by gravitational settling condensation or by pressure filtration condensation. On the gravitational settling condensation for the flocculated slurry, the cake was formed on the filter media and then the filtration could not be continued unless the formed cake was excreted by a mechanical hand-scraping device. In addition, the volumetric concentration of the condensate obtained from the flocculated slurry was at most 15 vol.%. On the other hand, the condensate obtained from the dispersed slurry still possessed fluidity when the concentration reached almost 40 vol.%, therefore we could collect the condensate without any hand-scraping devices. Furthermore, cake formation did not occur for the dispersed slurry, suggesting that the continuous filtration condensation is possible.