| 摘要 |
PCT No. PCT/AU96/00667 Sec. 371 Date Apr. 15, 1998 Sec. 102(e) Date Apr. 15, 1998 PCT Filed Oct. 23, 1996 PCT Pub. No. WO97/15427 PCT Pub. Date May 1, 1997A process for the preparation of a modified kaolin from a kaolin group mineral which includes expansion and contraction of layers of the kaolin group mineral. The layers comprising one Si-tetrahedral sheet and one Al-octahedral sheet. The expansion and contraction may be initiated by initial intercalation of a reagent which can penetrate kaolin layers to reach an interlayer region therebetween to form an intercalate. Subsequently, the intercalation nay be followed by de-intercalation which involves the removal of the reagent. By the above process, there is provided crystalline modified kaolins having the following properties: (i) an increased interlayer space compared to corresponding kaolin group minerals; (ii) an increased susceptibility to intercalation by cations, anions or salts compared to corresponding kaolin group minerals; and (iii) an increased exfoliated morphology compared to corresponding kaolin group minerals. |
