カオリナイトフロックの凝集構造に及ぼす塩濃度の影響について
1998 年 37 巻 4 号 p. 137-143
詳細
1998 年 37 巻 4 号 p. 137-143
The size, shape and porosity of kaolinite floc were examined by investigating the settling rates of flocculated kaolinite suspensions under various salt (NaCl) concentrations in alkaline bulk water (pH10).
Following conclusions were obtained;
1) When salt concentrations increased from 0.03mol/l to 0.2mol/l, floc diameter decreased from 620μm to 123μm, and floc porosity decreased from 99.2% to 98.5%. These results indicate that an incrase in salt concentration promotes the shrinkage of kaolinite floc.
2) On the other hand, when the salt concentration was between 0.2mol/l and 0.5mol/l, floc diameter and porosity were constant at 120μm and 98.5%, respectivly.
3) The results of 1) and 2) confirmed that the effect of salt concentration on the size, porosity, and structure of kaolinite floc changed at around 0.2mol/l.
4) In the high salt concentration region (from 0.2mol/l to 0.5mol/l), the porosity of kaolinite floc was higher than 98.5%. This fact can not be explained using a conventional face to face structural model such as kaolinite particles superimpoused over each other. Therefore, in order to explain this fact of high porosity, the structure of the kaolinite floc has a edge-to-face and a face-to-face structure. Thus a edge-to-face and a face-to-face linkage modes are existing together in the kaolinite floc.
