Chemical Changes During the Alteration of Micas

摘要: Di- and trioctahedral micas were altered to vermiculite-like minerals by extracting the K with sodium tetraphenylboron. Chemical analysis of original shows that loss is accompanied an increased on ignition, oxidation some Fe z+ :~+, divalent octahedral cations, mainly Mg z§ OH- (or sorption H+) decrease in net negative charge. The following reactions are suggested explain these changes: (1) replace- ment Na at interlayer sites; (2) release structural ions exposed replacement K, which decreases charge allows structure expand more be replaced; (3) 2+ reaction 4Fe + 4 (OH-) O,, ~ :;~ (O ~-) 2H20; (4) ions, possibly through holes left when lost. wide implications proposals discussed.