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。 EPR results show that there are two kinds of iron occurrences in Maomingshan kaolin, namely structural iron and free iron. Structural iron exists in the kaolinite lattice, substituting Fe3 + for Al3 + in the octahedron, and is divided into structural iron I in the orthorhombic crystal field symmetry and structural iron E in the higher crystal field. The content of iron (Fe2O3) is 0081% ~ 0122%, among which, the content of iron is 0031% ~ 055%, and the content of iron is 0050% ~ 0067%. The contents of Fe and E in iron are closely related to the crystallinity index of kaolinite, while the contents of iron and iron in E are positively correlated with the crystallinity index of kaolinite. Free iron exists in the form of impurities, with the content of (Fe2O3) 0467% ~ 0648%, mainly composed of hematite, limonite and goethite. Chemical iron removal does not affect the structure of iron, but can remove most of the free iron.