Saponite chemical analysis

Table I Approximate composition of saponite based on chemical analysis.

The crude material is, at first, suspended in water, at a concentration of about 5%, and the < 2 im fraction is collected by sedimentation. A sodium exchange is performed on this fraction in order to cause a swelling of the clay and to get a larger space gap between the layers. Three consecutive exchanges with a IN NaCl solution have been carried out. Chemical analysis shows that the Na amount remains constant after the second exchange. The suspension is dialyzed until it is free from Cl" ions. The Na-saponite is then available as a colloidal suspension. For 5g.l" suspensions, the measured pH is 8.8. 

TABLE 1 Chemical analysis of Na-cxchanged Saponite from Ballarat... 

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