PREPARATION OF ADSORBENT FOR WATER AND SULFUR COMPOUNDS FROM LOCAL CLAYS ( KAOLIN AND BENTONITE)

Abstract

The present research was carried out to study the possibility of preparing synthetic faujasite zeolite type Y from Iraqi Kaolin clay from Duekhla region and Bentonite clay from wadi Bashiraregion. Two procedures were used to prepare zeolite Y from metakaolin: the first one was achieved by adding sodium silicate to increase the SiO2/Al2O3 of kaolin clay while the second procedure was done by increasing SiO2/Al2O3in the clay by treating metakaolin with (2, 3, 4, 5 N) sulfuric acid solutions at room temperature, 60 and 90°C for 1 hr with solid: liquid ratio of 1: 4 to leach out some of its alumina. In the first procedure metakaolin was added to a solution contains sodium hydroxide and sodium silicate to make SiO2/Al2O3ratios = 3.5, 4.5, and 5.5, Na2O/SiO2=1, H2O/Na2O =40. The mixtures were aged at room temperature for 1, 3, and 5 days, and then crystallized at 95°C for 6 hours. The optimum crystallinity was 104.8% achieved by usingSiO2/Al2O3ratio equal to 5.5, and an ageing time of 3 days.The effect of crystallization temperature was tested using75, and 85 °C with metakaolin mixture SiO2/Al2O3=5.5,and ageing time 3 days. The crystallinity at 85°C was 99% but at 75°C the zeolite did not crystallized. In the second procedure amorphous dealuminated metakaolin (which had SiO2/Al2O3 = 7.64) was mixed with a solution of sodium hydroxide, aged at room temperature for 3days, and crystallized at 95°C for 6 hours.The crystallinity was 48%.