EDI

Linde Type F

Si(50), Al(50)

Contributed by Juliusz Warzywoda

Verified by T. Gier and by M. Sato

Type Material K10(Al10Si10O40) . wH2O (w ~ 8)

Method J. Warzywoda, R W. Thompson [1]

Batch Composition 5.26 K2O : Al2O3 : 3 SiO2 : 94.5 H2O

Source Materials

deionized water
potassium hydroxide (pellets, 85% KOH min.)
aluminum (wire, 99.999% Al)
silica (Cab-O-Sil M5, amorphous fumed SiO2)

Batch Preparation (for 4 g product)

(1) [20.0 g water + 9.26 g potassium hydroxide]; dissolve KOH pellets in HDPE a bottle. Divide into two equal portions
(2) [First half (1) + 0.719 g aluminuml;b dissolve the Al wire in half of the KOH solution by heating under reflux in a Teflon flask. Cool, filter and store in a HDPE bottle
(3) [Second half (1) + 2.42 g silica]; dissolve the silica in the remaining KOH solution and heat at 80-95¡C in a HDPE bottle. Cool,
filter and store in a HDPE bottlec
(4) [(2) + (3)]; heat (2) and (3) in HDPE bottles to 80-95"C and mix together.d Mix the resulting gel for 1-2 minutes at 1000 rpm with a mechanical stirrer to homogenize it e

Crystallization

Vessel: HDPE bottle
Temperature: 95¡C
Time: 96 hours
Agitation: static conditions with occasional mixing

Product Recovery

(1) Filter to recover solids
(2) Wash with deionized water until the pH of wash water is neutral
(3) Dry at 80¡C
(4) Yield: 4.4 to 4.7 g (near 100% based on Al2O3)

Product Characterization

XRD: Linde Type F (ref. [2], Table III, page 35)
Elemental Analyses: K2O : Al2O3 : 2SiO2 : 3H2O [3]
Crystal size and habit: small submicron prismatic crystals forming 0.5 to 3 um aggregates
Click here to view XRD pattern

References

[1] J. Warzywoda, R W. Thompson, Zeolites 11(1991) 577
[2] J. D. Sherman, in ACS Symp. Series 40, J. R Katzer (ed.), Am. Chem. Soc., Washington, D.C., 1977, p 30
[3] R M. Barer, J. W. Baynham, J. Chem. Soc. (1956) 2882

Notes

a. High density polyethylene.
b. The dissolution of aluminum powder in these caustic solutions generates heat and hydrogen and can be somewhat violent.
c. To avoid precipitation of solids from solutions (2) and (3), carry out crystallization immediately after solution preparations is complete.
d. A viscous aluminosilicate gel is formed instantaneously.
e. If no mechanical stirring is used, the gel appears to be very viscous with no visible fluid phase, and homogenization may be difficult. Brief heating of the gel at 950C will give a fluid phase and hand shaking can be used to homogenize it.