Preparation of LTA, HS and FAU/EMT intergrowth zeolites from aluminum scraps and industrial metasilicate

Na-LTA zeolite crystals were synthesized via hydrothermal method using aluminum scraps and industrial sodium metasilicate. The obtained hydrogel with molar composition: 3.741 Na2O:Al2O3:1.450 SiO2:175.520 H2O, was aged at room temperature for 14 h and heated at 80 °C for 6 h. The use of aluminum scraps provides well-crystallized cubic Na-LTA zeolites with truncated edges and apexes. When H2O/Al2O3 molar ratio was decreased: 3.741 Na2O:Al2O3:1.450 SiO2:92.50 H2O, there is formation of an intergrowth of FAU/EMT phases contaminated with LTA zeolite after 6 h of crystallization. The prolongation of the crystallization time to 48 h leads to the formation of hydoxysodalite zeolite. On the other hand, with the increase in aging time to 96 h, the crystal sizes of zeolite decrease.