Production of adsorbents from clay minerals for treatment of petrochemicals

Abstract

In investigating the kinetic relationships by decantation, an aqueous suspension with a dry-substance concentration of 10% was used. The washing was monitored on the basis of the washwater content of Na +, K +, and Ca=+ cations. The index used to rate the degree of washing was a relative value characterizing the quantity of salts remaining in the clay after each decantation. The static equilibrium with respect to Na +, K +, and Ca 2+ in the process of a given contact is established within 2 h; the potassium salts are almost completely removed after three decantations, whereas the calcium and sodium salts are removed after five and eight decantations, respectively. Washing the clay free of sodium, potassium, and calcium salts permits an increase in the specific quantity of olefins removed amounting to 45-50%. Here the maximum increase in clay activity is observed upon removal of 40-50% of the water-soluble salts, this being achieved by a single decantation with a settling time of about 2 h.