種セピオライト中の炭酸塩の除去および不純物イオンの置換サイト
2001 年 41 巻 1 号 p. 9-15
詳細
2001 年 41 巻 1 号 p. 9-15
Distributions of impurities in natural sepiolite samples produced in Japan, China, U. S. A. and Turkey were studied by Xray diffraction (XRD), thermogravimetry (TG), differential thermal analysis (DTA), differential thermogravimetry (DTG), thermal mass spectrometry (TMS) and chemical analyses. Calsite, magnesite and dolomite were contained in the sepiolite minerals. These carbonates contained in the samples could be easily eliminated by treating with 0.6mol/L aqueous solution of HCI. Weight losses in each sample obtained by TG measurement were consistent with the calculated values from the results of elemental analyses. After the samples were treated with HCl, the weight losses with the decomposition of carbonates did not observed in TG curves of the samples and only the dehydration from the samples contributed to the weight losses in TG-DTA-TMS curves. Especially, in the Japanese and Chinese samples, characteristic dehydration steps in the pure sepiolite were observed. The results of elemental analyses showed that both the Si4+ site in the SiO4 sheet and Mg2+ in the MgO6 sheet of sepiolite samples were partially substituted by metal ions such as aluminum, iron, manganese and titanium ions.
