Anomalies in Techniques for Preparing H‐Bentonites

Various procedures for the preparation of H‐bentonites to be used in physical‐chemical studies of clay systems have been examined. Their effects upon the exchangeable H and Al content of these bentonites have been evaluated by titration curves and chemical analyses. A procedure for reducing the amount of exchangeable Al in such preparations is proposed. This procedure involves pretreatment of the bentonite suspension with hydrochloric acid and sodium chloride solutions followed by removal of excess electrolyte and passage of the suspension through an H‐resin column. The exchangeable H and Al status of bentonites thus prepared is discussed.