STUDY ON THE EXISTING STATE OF Al~(3+) IN THE VERMICULITE INTERLAYER

We use cation exchange technology to transform natural vermiculite into Al~(3+) vermiculite and use XRD and DTA to analyze the existing state of Al~(3+) in the vermiculite interlayer.It shows that the Al~(3+) in interlayer of Al exchange vermiculite could not be extracted by KCl solution but by sodium citrate. So the Al~(3+) in interlayer of Al exchange vermiculite is unexchangeable ploy-hydroxide aluminium. Although the ionic potential of Al~(3+) is very high, the dehydrated temperature of Al exchange vermiculite is lower than that of original vermiculite. It indicates when Al~(3+) enters into the interlayer of vermiculite, Al~(3+) is hydrolyzed into Al(OH)~(2+) and Al(OH)~(2+) to reduce the efficient ionic potential of Al~(3+) leading to the decrease of dehydrated temperature of Al exchange vermiculite. The possible dehydrated equation is:[Al(OH_2)_6]~(3+)[Al(OH)_x(OH_2)_(6-x)]~(3-x)+xH~+,in which x3。