Elemental composition variability of clinoptilolite-rich tuff after the treatment with acid phosphate solutions

The changes in the elemental composition of the clinoptilolite-rich tuff from Oaxaca (México) produced by treatment with acid phosphate solutions at pH values from 0 to 6 was investigated as well as the behavior of the cation species from the clinoptilolite-rich tuff in relation to the dealumination of this zeolitic material. The elemental composition of the natural zeolite was determined by atomic absorption spectroscopy. According to the experimental data, the pH of the phosphate solutions influence the final elemental composition of the clinoptilolite-rich tuff and the dealumination of this material at pH 0 and 70 °C is around 30 wt.%. The concentration of Na and K from the clinoptilolite-rich tuff varies according to the concentration of aluminum present in this material after the acid phosphate treatment and their behavior depends on the nature of each chemical species.