Effect of Initial hydrothermal Temperatures on the Synthesis of Zeolites from Coal Fly Ash

  • Dr Hamzah Fansuri, Department of Chemistry, Institute Technology Sepuluh Nopember, Surabaya, Indonesia
  • Ms Dewi Muasyaroh, Department of Chemistry, Institute Technology Sepuluh Nopember, Surabaya, Indonesia
  • Dr Didik Prasetyoko, Department of Chemistry, Institute Technology Sepuluh Nopember, Surabaya, Indonesia

    • A large amount of fly ash generated every year from coal combustion in thermal power plants has become a potential source of pollution. There has been continuous effort to overcome the problem by converting it into usefull products such as zeolitic materials. This research aimed to study the effects of the initial hydrothermal temperatures of 100, 120, 150 and 180oC on the synthesis of zeolites. Prior to each initial hydrothermal treatment for 3.5 hours, approximately, 18 grams fly ash were stirred for 24 hours in 150 mL 3M KOH solution, followed by crystallization at 100oC for 6, 24, 48 and 96 hours. Products were characterized by XRD, SEM and the cation exchange capacity (CEC). Different types of zeolite were produced at different initial hydrothermal temperature, e.g. zeolite K-G (K-chabazite), zeolite K-F (K-edingtonite) and zeolite K-phillipsite. The CEC of zeolite products increased as the initial hydrothermal increased from 4.460 meq/100 g up to 12.964 meq/100 g which indicates that the initial hydrothermal process control the formation of zeolites.