EFFECTS OF RUBIDIUM, CESIUM, AND THALLIUM ON INTERLAYER POTASSIUM RELEASE FROM TRANSVAAL VERMICULITE

Potassium release characteristics of vermiculite samples treated with K and various amounts of Rb, Cs, and Tl were determined using a miscible displacement technique. The amounts of K released, K release rates, and activation energy of K release (E//a) were specifically examined. Increasng amounts of Rb, Cs, and Tl in the approximate range of 0. 0625 to 2. 00 cmol kg** minus **1 in vermiculite interlayers resulted in decreasing amounts of K released to leaching solution, decreasing K release rates, and increasing activation energies of K release. Kinetics of K released in some cases were zero-order at later stages of extraction time. The inhibitive effect of Rb, Cs, and Tl on K release from vermiculite, and their typical presence in micaceous minerals, suggest that they may be important components of mica chemistry.