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ELECTRIC CHARGES OF CLAYS
Author(s) -
CASHEN G. H.
Publication year - 1966
Publication title -
journal of soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.244
H-Index - 111
eISSN - 1365-2389
pISSN - 0022-4588
DOI - 10.1111/j.1365-2389.1966.tb01475.x
Subject(s) - alkali metal , hydroxide , ion , titration , inorganic chemistry , chemistry , neutralization , aluminate , charge (physics) , range (aeronautics) , viscosity , analytical chemistry (journal) , mineralogy , materials science , cement , metallurgy , organic chemistry , physics , composite material , antibody , immunology , biology , quantum mechanics
Summary Conductimetric titrations, with NaOH, of solutions containing Al ion detect two OH‐ions of Al in the acid range, with OH/Al ratios of ions such as Al(OH) 2+ and A1 6 (OH) 3+ 15 ; in the alkaline range aluminate Al(OH) −1 4 is formed. Similar titrations of an Al‐kaolin, prepared by acid washing, give results that can be adequately interpreted in terms of these three ions, i.e. by the reaction with alkali of Al 3+ ions balancing the permanent isomorphous replacement charge. If there are reactions with alkali at the edge‐faces of the kaolin, e.g. the neutralization of residual positive edge‐charge, these edge‐charges must be small in comparison with the permanent charge. Bonding by the complex ion Al 6 (OH) 3+ 15 , formed on the surfaces of clay particles, explains why the viscosity of Al clays is greatest at the five‐sixths stage of neutralization, because the formation of the hydroxide Al(OH) 3 is theoretically equivalent to the measurement of the permanent charge.