Centrifuged fractions, ranging in size from 2·0 to 0·05 μ of a Wyoming bentonite, Bentonita de Durango from Mexico, and Helms clay from Texas were studied. The variation in replacement of Na+, Ca2+, Mg2+, K+, and H+ from these heteroionic clay systems under specific equilibrium conditions of salt concentrations was measured.
The displacement cation distribution was monitored by using specific ion glass electrodes, such as a sodium ion electrode, a cationic glass electrode, a calcium ion electrode and a Tektite electrode. Some factors affecting the exchange reactions are discussed and application of findings to drilling and production techniques is indicated.