Effects of the Exchangeable Ion on the Dehydration Properties of Vermiculite

Ion‐exchange studies were made on a selected vermiculite from South Carolina, the vermiculite having a base‐exchange capacity of about 100 me. per 100 gm. The material was saturated with magnesium, calcium, barium, sodium, and potassium ions, and differences in dehydration characteristics were noted. In general, it was found that the charge‐radius ratio of the exchangeable ion present exerts considerable influence on the amount and stability of the inter‐layer water present. No correlation between the nature of the exchangeable ion and the expandability of the vermiculite could be found.