オケナイトの水熱処理

スチブンサイトの成因に関する実験的研究(第5報)

抄録

In order to investigate the genesis of stevensite experimentally, naturally occurring okenite was treated hydrothermally with 0.5 mol/l magnesium chloride solution and with basic magnesium carbonate for Mg (in basic magnesium carbonate)/Si (in okenite) molecular ratios ranging from 0.1 to 1.5. As a result, okenite was altered to “hydrated talc” by treatment with magnesium chloride solution. On the other hand, it was altered to stevensite (Mg/Si = 0.3-0.5), and “hydrated talc” and serpentine (Mg/Si = 0.75-1.5) by basic magnesium carbonate treatment. Furthermore, when sodium hydrogencarbonate was added to the reaction system, larger amount of stevensite (Mg/Si =0.1-1.0) and serpentine (Mg/Si = 1.5) were obtained. The mechanism of the conversion process was quite similar to other studies on calcium silicates as reported previously.