Zeolite A prodn. from meta:kaolin and sodium hydroxide - by mixing to aq. slurry and heating, for short reaction time

摘要

The process involves mixing meta-kaolin with water and NaOH intensively to an aq. slurry in which the molar ratios are NaiO:Al2O3 4-6, SiO2:Al2O3 1.9-2.25 and H2O:Na2O 20-50. This is then heated to not 80 (perf. 85-95) degrees C and the crystalline zeolite powder is filtered off after a reaction time of not 60 min. washed with water and dried. The process can be carried out easily on the large technical scale, in spite of the use of cheap raw materials. The reaction time is much shorter than usual and the prods. are stable in the mother liquor for long periods, without loss of lime binding power.