L1 /
8
CH3041
CLAYS II
Common Clay Minerals are:
1) 1:1 mineral
Si4Al4O10(OH)8
Kaolinite
2)
2:1 mineral Mx(Al,Fe,Mg)2(Si,Al)4O10(OH)2
Vermiculite Smectite Chlorite
• Montmorillonite (Smectite group) K form
K+x+y(Al2-xMgx) (Si4-yAly)O10(OH)2 x» 0.4, x> y
K+x+y(Al2-xMgx) (Si4-yAly)O10(OH)2 x» 0.4, x> y
• Isomorphous substitution where one atom
(ion) is replaced in a structure by another of a similar size. Due to different electron counts this results in charge developing.
(ion) is replaced in a structure by another of a similar size. Due to different electron counts this results in charge developing.
Al3+ 0.050nm
Si4+ 0.041nm tetrahedral sheets
Fe2+ 0.075, Mg2+ 0.065, Al3+ 0.050 octahedral
Fe2+ 0.075, Mg2+ 0.065, Al3+ 0.050 octahedral
