【摘要】 ＥＰＲ研究结果表明，茂名山阁高岭土中铁的赋存状态有两种，即结构铁和游离铁。结构铁存在于高岭石晶格中，以Ｆｅ３＋置换八面体中的Ａｌ３＋，分为处于斜方晶场对称的结构铁Ｉ和处于更高晶场对称的结构铁Ｅ。结构铁含量（Ｆｅ２Ｏ３）００８１％～０１２２％，其中，Ｉ铁含量００３１％～００５５％，Ｅ铁含量００５０％～００６７％。Ｉ铁和Ｅ铁含量均与高岭石结晶度指数呈密切负相关，而Ｅ铁和Ｉ铁含量比值与高岭石结晶度指数呈正相关。游离铁以杂质形式存在，含量（Ｆｅ２Ｏ３）０４６７％～０６４８％，主要为赤铁矿、褐铁矿和针铁矿。化学除铁处理对结构铁不产生影响，而可去除绝大部分游离铁。更多还原

【Abstract】 Studies of kaolins from Shange with EPR technique indicate that the iron in kaolins exists in two forms: structural Fe 3+ ion, which is isomorphously substituted for Al 3+ ion in the octahedral sheet in kaolinite and free Fe 3+ ion, which exists in hematite, limonite and geothite. Structural iron which exists in the octahedral sheet occupies two distinct substitutional sites (I and E). The I iron is due to Fe 3+ ion at a site having orthorhombic symmetry, and the E iron is due to Fe 3+ ion at a site of higher symmetry. The structural iron content is 0.081%～0.122% Fe 2O 3 (I iron 0.031%～0.055%, E iron 0.050%～0.067%). The free iron content is 0.467%～0.648% Fe 2O 3. It is concluded that the content of I iron and that of E iron are both correlated inversely with the X_ray crystallinity of kaolinite, whereas the ratio of E iron content to I iron content is correlated directly with the degree of order of kaolinite. Chemical bleaching fails to affect structural iron, but can remove most of free iron from kaolin.更多还原