Crystal growing of sodium type 13X zeolite by continuous crystallization method

NaX zeolite crystals of a uniform particle size of 50 $\mu$m were grown by continuous crystallization method from seed crystals (10~20 $\mu$m) added into a 0.5~2.0 g mother liquor having a composition $3.5Na_2O : Al_2O_3: 2.1SiO_2: 1000H_2O$. In order to investigate the crystal growing by continuous method, the mother solution was supplied after 7 days, 5 days, 3 days and 1 day, respectively. The seeding resulted in an increase in the fraction of large crystals compared with unseeded batches and successfully led to an uniform NaX zeolite crystal. It was postulated that the seeding in the synthesis mixture leaded out increase of surface area for physical contact reaction and directed growth of seed crystal without the nucleation in the synthesis gel.

연속결정화 방법에 의한 13X 제올라이트 결정성장

NaX seed결정(10~20 $\mu$m)을 $3.5Na_2$O : $Al_2O $: $2.1SiO_2$ : $1000H_2$O 용액에 0.5~2.0g 첨가한 후 연속결정화법으로 50 $\mu$m의 균일한 결정을 성장시켰다. 연속결정화법에 의한 결정성장을 시험하기 위하여, 모액을 7일, 5일, 3일, 2일과 1일 간격으로 공급하였다. Seed 첨가의 결과는 첨가하지 않은 용액과 비교하여 보다 균일하고 큰 결정들을 얻었다. 합성용액에 seed의 첨가는 반응물과 물리적인 접촉 면적을 초래하여 합성 겔의 핵성장 없이 seed 결정의 결정성장을 확인할 수 있다.