ABSTRACT The combination of pillarization and charge neutralization with Li+ can make montmorillonite an important support material for industry and decontamination of pollutants in soil and water. Montmorillonite characterization techniques were described in detail, and pillarization procedures were used, after Li+ saturation, to modify and manipulate the chemical and mineralogical surface properties of this montmorillonite. Eight samples were produced: 1) natural montmorillonite (Chisholm Mine – MMT); 2) Li+ saturated montmorillonite (MMTLi); 3) polyethylene glycol (PEG) Al-pillared montmorillonite (AlPEG); 4) PEG […]

Maghemite (g-Fe2O3) is the most usually found ferrimagnetic oxide in red basalt-derived soils. The variable degrees of ionic substitution of Fe3+ for different metals (e.g. Ti4+, Al3+, Mg2+, Zn2+, and Mn2+) and non-metals in the maghemite structure influence some cristallochemical features of this iron oxide. In this study, synthetic Zn-substituted maghemites were prepared by co-precipitation in alkaline aqueous media of FeSO4.7H2O with increasing amounts of ZnSO4.7H2O to obtain the following sequence of Fe3+ for Zn2+ substitutions: 0.0, 0.025, 0.05, 0.10, […]

Hematites were synthesized with different degrees of isomorphic substitution (IS) of Fe for Al to a maximum of 16Almol%.The minerals were characterized by X-ray diffraction, total chemical analysis, extraction of iron and aluminum soluble in ammonium acid oxalate (Feo+Alo), determination of the anion exchange capacity (AEC) and specific surface area (SSA).The results showed that the synthesis methods resulted in a minimum amount of impurities and that, in a general way, the foreseen values of isomorphic substitution were achieved.The SSA values […]