Hydrothermal Synthesis of Clay Minerals from Ground Talc

为了研究粘土矿物的水热合成，采用不同的盐溶液对机械化学活化的滑石粉进行水热处理。得到的结果如下：1。用振动磨将滑石粉粉碎成x射线非晶材料。然而，29Si-NMR数据表明，这种非晶材料含有一簇原始层状结构的滑石。用钠盐（NaOH,Na_2CO_3, NaHCO_3, NaCl）溶液或蒸馏水在200或250ºC温度下水热处理168小时，得到三八面体蒙脱石和结晶不良的滑石。然而，没有得到海鞘。铝盐(AlCl_3, Al（NO_3)_3, Al_2(SO_4)_3, NaAlO_2）溶液在200或250ºC的水热条件下处理240小时，产物因Al / Si（原料）比和pH条件的不同而不同。在酸性条件下，低铝硅比形成三八面体蒙脱石。在中等Al/Si比下，形成双八面体蒙脱石。高岭石形成于高铝硅比条件下。另一方面，在碱性条件下，低铝硅比条件下形成三八面体蒙脱石，高铝硅比条件下形成蛇纹石。

In order to investigate the hydrothermal synthesis of clay minerals, mechanochemically activated ground talc was hydrothermally treated with various salt solutions. Results obtained are as follows ;1. Talc was changed into X-ray amorphous material by the grinding using a vibrating mill. However, 29Si-NMR data showed that this amorphous material contains a cluster of original layr structure of talc.2. Tri-octahedral smectite and poorly crystallized talc are formed from the ground talc by the hydrothermal treatment with Na salts (NaOH,Na_2CO_3, NaHCO_3, and NaCl) solutions or distillled water at 200 or 250ﾟC for 168 hours. However, no sepiolote was obtained.3. In the Hydrothermal treatment with Al salt (AlCl_3, Al(NO_3)_3, Al_2(SO_4)_3, and NaAlO_2) solutions at 200 or 250ﾟC for up to 240 hours, products were differed depend on the Al to Si (in the starting material) ratio and pH conditions. In the acidic condition, tri-octahedral smectite was formed in the case of low Al/Si ratio. In the medium Al/Si ratio, di-octahedral smectite was formed. Kaolinite was formed in high Al/Si ratio. On the other hand, tri-octahedral smectite was formed in the low Al/Si ratio and serpentine was obtained in the high Al/Si ratio, in basic condition.