Similar articles

Abstract: Selective dissolution with ammonium oxalate was carried out to extract amorphous matter in some kaolins from China. Ammonium oxalate extraction is an effective method to extract amorphous constituents without destroying the kaolinite crystalline structure. The study showed that, absolute amounts of amorphous constituents in kaolins are in the order Al>Si>Fe, but that relative amounts are in the order Fe>Al>Si. The amorphous phases are probably mainly in the form of separate particles, or colloidal particles absorbed on the surface of kaolinite particles.Compared to older kaolins, younger kaolins contain much more amorphous iron content.

[1] Brindley,G.W.,Kao ChinChu,Harrison,J.L.,et al.,1986.Relation between structural disorder and other characteristic of kaolinites and dickites. Clays and Clay Minerals, 34: 239-249.

[2] Delgado,R.,Delgado,G.,Ruiz A.,et al.,1994.The crystallinity of several Spanish kaolins: Correlation with sodium amylobarbitone release. Clay Minerals, 29: 785-797.

[3] Deligny,D.,Navrotsky,A.,1999.Energetics of kaolin polymorphs. American Mineralogist, 84(4): 506-516.

[4] Dixon,J.B.,1989.Kaolin and serpentine group minerals.In: Minerals in Soil Environment,eds: Dixon,J.B.,Weed,S.B.,Second edition. Wisconsin, p.467-526.

[5] Follett,E.A.C.,McHardy,W.J.,Mitchell,B.D.,et al.,1965.Chemical dissolution techniques in the study of soil clays. Clay Minerals. 6: 23-24.

[6] Jefferson,D.A.,Tricker,M.J.,Winterbottom,A.P.,1975.Electron-microscopic and Mossbauer spectroscopic studies of iron-stained kaolinite minerals. Clays and Clay Minerals, 23: 355-360.

[7] Lee,S.Y.,Jackson,M.L.,Brown,J.L.,1975.Micaceous occlusions in kaolinite observed by untramicrotomy and high resolution electron microscopy. Clays and Clay Minerals, 23: 125-129.

[8] Robertson,I.D.M.,Eggleton,R.A.,1991.Weathering of granitic muscovite to kaolinite and halloysite and of plagioclase: derived kaolinite to halloysite. Clays and Clay Minerals, 39: 113-126(in Chinese,with English abstract).

[9] Shen Zhongyue,1994.Enrichment of dickite and nacrite from kaolins.Kuangwu Yanshi, 14(2): 16-21(in Chinese,with English abstract).

[10] Shen Zhongyue,Ye Ying,1995.Study on Fangjiashan kaolinite minerals in Fangjiashan kaolin.Zhejiang Province.Sinica Petrologica et Mineralogica,14(1):57-63(in Chinese,with English abstract).

[11] Shen Zhongyue,Ye Ying,1996.Goyazite mineral in dickite deposit from Zhuji,Zhejiang and its origin,Geology and prospecting,32(4):32-35(in Chinese,with English abstract).

[12] Smith,B.F.L.,Mitchell,B.D.,1987.Characterization of poorly order minerals by selective chemical methods.In: A Handbook of Determinative Methods in Clay Mineralogy. Ed: Wilson,M.J.,Blackie,Glasgow. p.275-291.

[13] Weaver,C.E.,Pollard,L.D.,1973.The Chemistry of Clay Minerals.Elsevier Scientific Publishing Company.Amsterdam,p.125-130.

[14] Wilson,M.J.,1987.Determinative methods: a brief overview.In: A Handbook of Determinative Methods in Clay Mineralogy.Ed: Wilson M.J.,Blackie,Glasgow,p.295-299.

[15] Wilkin,R.T.,Barnes,H.L.,1997,Formation processes of framboidal pyrite,Geochimica et Cosmochimica Acta,6(2): 323-339.