简介：Thechangesofclaymineralassociationafterhigh-gradientmagneticseparation(HGMS)treatment,andtheeffectsofchemicalandphysicaltechnologiesonconcentratingFeoxidesformiansoilsincentralandsouthernChinawereinvestigatedbymeansofX-raydiffraction(XRD)andchemicalanalysismethods.ResultsindicatedthattheconcentratingtimesofFeoxidesbyHGMStreatmentwerethelargestfor0.2-2μmsizefractionintheexaminedsoils.Forthesoilsinwhich2:1phyllosilicatesweredominant,concentratingtimesofironoxidesbyHGMStreatmentwerelargerthanby5molL^-1NaOHtreatment.Phyllosili-catesweredecreasedafterHGMStreatment;however,thedecreasewaslessthanthatofkaolinite,Thegoethite/(goethite+hematite)valuesinFeoxidesofthesoilskeptvirtuallyconstantafterHGMStreatment.