This invention relates to the production of synthetic, crystalline ferrierite, an alumino-silicate zeolite. Ferrierite is relatively scarce in nature, but has been found in large deposits in the Western United States. Natural ferrierite has the general formula (Na, K).sub.0.5-4 Ca.sub.0-1 Mg.sub.0.5-3 (Al.sub.4-7 Fe.sub.0-1 Si.sub.27-31')0.sub.72 . 18-23 H.sub.2 O where the sum of the moles of alkali and alkaline earth oxides equal the sum of the moles of alumina and ferria, EQU .SIGMA.(Na.sub.2 O + K.sub.2 O + CaO + MgO) .apprxeq. .SIGMA.(Al.sub.2 O.sub.3 + Fe.sub.2 O.sub.3), and .SIGMA.(Si + Al + Fe) = 36.
Natural ferrierite from Kamloops Lake, British Columbia, Canada has been shown by P. A. Vaughan, Acta Crystallographica 21, 983 (1966), to be orthorhombic with the space group I 2/M 2/M 2/M. Natural ferrierites from various localities do not have exactly the same X-ray powder pattern, but the X-ray powder pattern of ferrierite from each locality fits the theoretically allowed lines for the space group 2/M, 2/M, 2/M, as shown below in Table A, and the differences are presumably caused by variable cation contents. Synthetic strontium ferrierites of the approximate composition SrO:Al.sub.2 O.sub.3 : 7-9 SiO.sub.2, the X-ray powder patterns of which also fit the allowed lines, have been described in the literature by R. M. Barrer and D. J. Marshall, Journal of the Chemical Society 1964. 485. Synthetic strontium and calcium ferrierite were made at 350.degree.-370.degree. C and 1,020-1,632 atmospheres by D. B. Hawkins, Materials Research Bulletin, 2 951 (1967). Also, synthetic sodium ferrierite was made by E. E. Senderov, Geochemistry (English Translation) 9. 848 (1963). Synthesis of strontium ferrierites by Barrer and Marshall were carried out at temperatures of 260.degree., 340.degree. and 380.degree. C at pressures of 39, 144 and 235 atmospheres, respectively. Even though such high temperatures as 340.degree. and 380.degree. were employed, the synthesis of strontium ferrierite required 2-4 days. Twenty days were required to crystalize strontium ferrierite from a 1.5 SrO:1.0 Al.sub.2 O.sub.3 :9SiO.sub.2 :500H.sub.2 O slurry at 260.degree. C.
The syntheses of stontium ferrierite, reported by Barrer and Marshall, at 340.degree. and 380.degree. C are relatively difficult, and the product ferrierite is frequently contaminated with impurities. By using the seeding technique, described below, we have reduced the temperatures, pressures and times required for synthesis; also we have greatly improved the reliability of the process.
Furthermore, no natural ferrierite has been shown to contain substantial amounts of strontium or lithium or both. Table B shows that samples of natural ferrierite from five localities are mainly sodium, potassium, magnesium, calcium aluminosilicate hydrates, with some possible substitution of iron for aluminum. The compositions of natural ferrierites have recently been reviewed by Wise and Tschernich (American Mineralogist (1976), vol. 61, p. 60-66); they did not find lithium in natural ferrierite samples.
TABLE A __________________________________________________________________________ COMPARISON OF D SPACINGS OF TWO NATURAL AND SYNTHETIC STRONITIUM FERRIERITES WITH THE ALLOWED LINES FERRIERITE Theoretical for I 2/M 2/M 2/M Where a = 19.16 FERRIERITE SYNTHETIC b = 14.13 Kamloops Lake FERRIERITE, STRONTIUM and c = 7.49 B.C., Canada Agoura, Ca. FERRIERITE* Relative Relative Relative hkl dA dA Intensity dA Intensity dA Intensity __________________________________________________________________________ 110 11.37 11.3 20 11.3 3 -- -- 200 9.58 9.61 100 9.47 50 9.49 75 020 7.06 7.00 30 7.07 38 7.07 20 -- -- 6.96 15 101 6.98 6.61 20 6.59 3 6.61 55 011 6.62 5.84 50 5.75 15 5.77 15 310 5.82 -- -- 5.64 14 -- -- 220 5.69 -- -- -- -- 5.43 5 211 5.44 4.96 10- -- -- 4.96 15 121 4.964 -- -- -- -- -- -- 301 4.860 4.80 10- 4.75 2 4.76 15 400 4.790 4.58 10- 4.56 1 -- 130 4.574 -- -- -- -- -- 321 4.004 3.99 90 3.98 35 3.99 45 031 3.987 -- -- 3.94 35 3.94 35 420 3.965 3.88 10 -- -- 3.86 25 411 3.880 3.791 20 3.78 65 3.78 50 330 3.791 -- -- -- -- 3.74 10 002 3.745 3.69 50 3.66 12 3.67 30 510 3.698 -- -- -- -- 231 3.681 3.54 80 -- -- 3.555 10 112 3.557 -- -- 3.54 100 3.536 90 040 3.532 3.49 80 3.48 18 3.483 100 202 3.488 3.42 20 -- -- 3.389 15 501 3.411 3.31 20 3.31 35 3.313 20 240 3.314 3.20 10 -- -- -- -- 600 3.193 3.15 30 -- -- 3.142 55-141 3.152 -- -- 3.14 12 -- -- 312 3.149 3.07 30 -- -- 3.058 45 521 3.072 -- -- 3.05 12 -- -- 431 3.064 2.97 30 -- -- 2.960 25 530 2.972 -- -- 2.945 11 2.938 25 402 2.950 2.90 20 -- -- 2.897 35 620 2.910 2.72 20 -- -- 2.715 30 422 2.722 2.64 20 2.644 7 2.646 15 051 2.644 2.58 30 2.582 10 2.583 10 350 2.584 -- -- -- -- -- -- 701 2.571 __________________________________________________________________________ *Barrier and Marshall, American Mineralogist 50, 484 (1965)
TABLE B __________________________________________________________________________ Chemical Analysis of Natural Ferrierite* Locality Itomuka, Kamloops Albero Japan Lake, Bassi, Yajima Graham Alietti Agoura,** Agoura,** Sonora Pass,** Oxide et al.(1971) (1918) (1967) Calif. Calif. Calif __________________________________________________________________________ SiO.sub.2 71.21 69.13 56.80 74.40 75.64 66.17 Al.sub.2 O.sub.3 9.84 11.44 12.71 8.51 9.39 10.71 Fe.sub.2 O.sub.3 0.05 3.29 0.04 0.01 0.99 TiO.sub.2 -- 0.10 MnO -- CaO -- none 5.52 0.13 0.14 0.55 MgO 1.70 2.92 4.12 1.07 1.02 2.79 Na.sub.2 O 1.59 3.97 0.27 1.91 2.33 K.sub.2 O 2.85 0.36 0.82 2.48 2.80 1.54 CO.sub.2 -- 2.84 H.sub.2 O(+) H.sub.2 O(-) 4.25 8.63 13.05 4.16 10.15 11.46 8.67 17.25 100.12 100.87 100.79 100 100 100 __________________________________________________________________________ Chemical Formulae of Ferrierite (Na.sub.1.32 K.sub.1.57)Mg.sub.1.09 (Si.sub.30.95 Al.sub.5.03 Fe.sub.0.01) .sub.35.99 O.sub.72.01 . 18.82H.sub.2 O (Yajima, et al.) (Na,K).sub.4 Mg.sub.2 (Si.sub.30 Al.sub.6)O.sub.72 (OH).sub.2 . 18H.sub.2 O(Staples, 1955) Na.sub.1.5 Mg.sub.2 Si.sub.30.5 Al.sub.5.5 O.sub.72 . 18H.sub.2) (Vaughan, 1966) K.sub.0.51 Na.sub.0.25 Ca.sub.0.99 Mg.sub.2.98 (Fe.sub.1.20 Al.sub.7.25 Si.sub.27.50)0.sub.72 . 23 . 12H.sub.2 O (Alietti, 1967) Na.sub.1.8 K.sub.1.4 Mg.sub.0.6 (Si.sub.31.6 Al.sub.4.4)0.sub.72 . 18H.sub.2 O (Wise et al., 1969) __________________________________________________________________________ *From S. Yajima, et al., Mineralogical Journal, 6 343 (1971). **W. S. Wise, et al., American Minerologist, 54, 887 (1969).