Abstract: | Sodium silicate-aluminate aqueous systems with various contents of Na2O and SiO2 containing triethanolamine were crystallized. Optimum Na2O and SiO2 contents have been observed to give NaA and NaX zeolite crystals with dimensions up to 80 μm. For NaA crystals the values are: ∼ 3.5 mass% Na2O, ∼ 1.65 mass% SiO2; for NaX crystals ∼ 2.5 mass% Na2O, ∼ 1.5 mass% SiO2. – The effect of other additives on crystal size is proved. – The results are discussed in terms of nucleation and growth, reaction rate, and supersaturation. Supposition are made to gain larger crystals by maintaining the excess of solute over a longer period of time. |