ANA

ANA

Analcime

Si(68), Al(32)

Contributed by B. W. Garney

Verified by N. Evmiridis and by F. Farzaneh

Type Material Na_x[Al_xSi_48-xO₉₆ :16 H₂O (x = 15 to 17)

Method Developed from J. F. Charnell [1], and A. Dyer, A. M. Yusof [2]

Batch Composition 4.5 Na₂O : Al₂O₃ : 4.5 SiO₂: 3.0 H₂SO₄: 380 H₂O : 6.1 triethanolamine ^a

Source Materials

demineralized water
aluminum sulfate [General Purpose Reagent, Al₂(SO₄)₃^.16 H2O]
sodium metasilicate (Technical Grade, Na₂SiO₃^. 5 H₂O)
triethanolamine [General Purpose Reagent, N(C₂H₄OH)₃]

Batch Preparation (for approximately 7 g product) [3,4]

(1) [55 g water + 9.8 g aluminum sulfate], stir until dissolved; filter through 0.7 micron glass microfibre filter
(2) [36.5 g water + 14.9 g sodium metasiicate + 12.2 g triethanolamine], stir until dissolved; filter through 0.7 micron glass microfibre filter
(3) [(1) + (2)], stir gently until gel thickens (do not over-stir)

Crystallization

Vessel: 150 mL Teflon-lined autoclave ^bTime: 24 hours
Temperature: 200¡C (autoclave heated in the oven)
Agitation: none

Product Recovery

(1) Cool to room temperature and filter to recover solids
(2) Wash with distilled water until pH of filtrate < 10
(3) De-agglomerate by adding 10 mL of 10% ethanol in water and immerse in a 150 watt ultrasonic bath for approximately 1 hour
(4) Dry at l00¡C
(5) Yield: approximately 90%

Product Characterization

XRD: ANA (only crystalline phase)
Elemental Analysis: 1.06 Na₂O : Al₂O₃ : 4.3 SiO₂: 2 H₂O
H₂O (Wt. loss at 500⁰C): 8.29% (± 0.20)
Na₂O: 14.6% (± 1.5)
Al₂O₃: 22.7% (± 1.5)
SiO₂: 57.3% (± 0.5)
Crystal Size and Habit: polycrystalline non-porous spherulites £ 180 um dia. [2]
Click here to view XRD pattern

References

[1] J. F. Charnell, J. Cryst. Growth 8 (1971) 291
[2] A. Dyer, A. M. Yusof, Zeolites 7 (1987) 191
[3] B. W. Garney, Fusion Technology 21 (1992) 604
[4] B. W. Garney, UK Patent Application 9011151.9

Notes

a. This preparation gives the non-porous form of analcime. Replacing aluminum sulfate with an equivalent weight of sodium aluminate gives the porous form of analcime. Gel composition: 6.5 Na₂O : Al₂O₃: 4.5 SiO₂: 380 H₂O: 6.1 triethanolamine.

b. The method of heating the gel is very important if large crystals are required. The largest crystals were obtained when the autoclave was placed in a laboratory oven where the heat flow was uniform all around the pot. Experiments using autoclaves which were heated by electrical jackets around the sides were not so successful.