| 摘要 |
<p>PURPOSE:To obtain gypsum with higher whiteness improved in quality, by putting a gypsum slurry drawn from specified processes to such treatments as water content regulation, surfactant addition, application of shear force and classification to separate a fraction containing large-sized gypsum granules. CONSTITUTION:An absorption liquor containing gypsum granules and dust is drawn from the gypsum crystallization region 1 of an exhaust gas desulfurizer with wet-type limestone-gypsum method and regulated by a solid-liquid separatory means 2 to obtain a gypsum slurry <=20wt.% in water content. This slurry is then transferred to a high shear stress application means 3 where both water and a surfactant are added to the slurry to adjust the pH level and solid concentration thereof to 1-3 and 1-30wt.%, respectively, followed by applying high shear force on the slurry using e.g. a homomixer to form a dispersion, which is then divided into a fraction predominant in large-sized gypsum granules and the other fraction containing dust by a classification means 4 such as a sedimentation tank. For the former fraction, the absorption liquor is separated and removed by a solid-liquid separatory means 5, thus obtaining the objective gypsum of high whiteness.</p> |
