Formation of gyrolite in the CaO-quartz-Na2O-H2O system

• Autorzy: Baltakys K. , Siauciunas R.
• Języki publikacji: EN

Abstrakty

EN

Optimizing the duration and/or the temperature of hydrothermal synthesis of gyrolite has been investigated by adding NaOH solution into an initial mixture of CaO-quartz-H2O. The molar ratio of the primary mixture was C/S = 0.66 (C - CaO; S - SiO2). An amount of NaOH, corresponding to 5 % Na2O from the mass of dry materials, added in the form of solution and additional water was used so that the water/solid ratio of the suspension was equal to 10.0. Hydrothermal synthesis of the unstirred suspension was carried out in saturated steam at 150, 175, 200 oC. The duration of isothermal curing was 4, 8, 16, 24, 32, 48, 72 and 168 h. The temperature of 150 oC is too low for the synthesis of gyrolite; the stoichiometric ratio C/S = 0.66 is not reached even after 168 h of synthesis neither in pure mixtures nor in mixtures with addition of Na2O. Na+ ions significantly influence the formation of gyrolite from the CaO-quartz mixtures in the temperature range from 175 oC to 200 oC. Gyrolite is formed at 175 oC after 168 h and at 200 oC after 16 h of isothermal curing. On the contrary, in pure mixtures it does not form even after 72 h at 200 oC. Na+ ions also change the compositions of intermediate and final products of the synthesis. In mixtures with 5% Na2O, intermediate compounds are C-S-H(I) and Z-phase, and the final products are gyrolite and pectolite. Meanwhile, in mixtures without this additive, the main intermediate compounds alfa-C2S hydrate and C-S-H(II), and the main products are 1.13 nm tobermorite and xonotlite.

Słowa kluczowe

EN

gyrolite; Z-phase; calcium silicate hydrate; X-ray diffraction

• Wydawca: De Gruyter
• Czasopismo: Materials Science Poland
• Rocznik: 2007
• Tom: Vol. 25, No. 4
• Strony: 1089--1100
• Opis fizyczny: Bibliogr. 29 poz.

Twórcy

autor

Baltakys K.

autor

Siauciunas R.

• Department of Silicate Technology, Kaunas University of Technology, Radvilenu 19, LT - 50270 Kaunas, Lithuania

Bibliografia

• [1] http://mineral.galleries.com/minerals/silicate/gyrolite/gyrolite.htm, as on 17 March 2007.
• [2] FLINT E.P., MCMURDIE H.F., WELLS L.S., J. Res. Natl. Bur. Stand., 21 (1938), 617.
• [3] BABUSHKIN V.I., MATVEEV G.M., MCHEDLOW-PETROSSYAN O.P., Thermodynamics of Silicates, Stroyizdat, Moscow, 1962 (in Russian).
• [4] EL-HEMALY S.A.S., ABO-EL-ENEIN S.A., DESSOUKI A.M., ISMAIL M.R., II Cemento, 3 (1986), 227.
• [5] SUZUKI K., NISHIKAWA T., IKENAGA H., ITO S., Cem. Concr. Res., 16, (1986), 333.
• [6] BLAKEMAN E.A., GARD J.A., RAMSAY C.G., TAYLOR H.F.W., J. Appl. Chem. Biotechn. 24 (1974), 239.
• [7] AL-WAKEEL E.I., EL-KORASHY S.A., EL-HEMALY S.A., RIZK M.A., J. Mater. Sci., 36 (2001), 2405.
• [8] MIYAKE M., IWAYA M., SUZUKI T., J. Amer. Ceram. Soc., 73 (1990), 3524.
• [9] NOCUN-WCZELIK W., Cem. Concr. Res., 29 (1999), 1759.
• [10] NOCUN-WCZELIK W., Cem. Concr. Res., 27, (1997), 83. K. BALTAKYS, 1100 R. SIAUCIUNAS
• [11] FAUCON P., CLAUDE-PETIT J., J. Amer. Ceram. Soc., 82, (1999), 1307.
• [12] SHRIVASTAVA O.P., KOMARNENI S., Cem. Concr. Res., 21, (1991), 83.
• [13] MERLINO S., Mineral. Mag., 52 (1988), 377.
• [14] SUKHESWALA N., AVASIA R.K., GANGOPADHYAY M., Mineral. Mag., 39 (1974), 658.
• [15] SEAGER A., Mineral. Mag., 37 (1969), 147.
• [16] ELTON N.J., HOOPER J.J., HOLYER V.A.D., Mineral. Mag., 62, (1998), 271.
• [17] MACKAY A.L., TAYLOR H.F.W., Mineral. Mag., 30 (1953), 80.
• [18] SHAW S., HENDERSON C.M.B., CLARK S.M., Amer. Min., 87 (2002), 533.
• [19] SHAW S., Ph.D. Thesis, University of Manchester, 1999.
• [20] MIYAKE M., KOMARNENI S., ROY R., Mater. Res. Bull., 24 (1989), 311.
• [21] KOMARNENI S., BREVAL E., MIYAKE M., ROY R., Clays Clay Miner., 35 (1987), 385.
• [22] EL-KORASHY S.A., J. Ion Exch., 15, (2004), 2.
• [23] EL-KORASHY S.A., AL-WAKEEL E.I., EL-HEMALY S.A., RIZK M.A., Egypt J. Chem., 45, (2002), 723.
• [24] WINTERS M.A., RICHTER J.D., SAGAR S.L., LEE A.L., LANDER R.J., Biotechnol. Prog., 19 (2003), 440.
• [25] SIAUCIUNAS R., BALTAKYS K., Cem. Concr. Res., 34 (2004), 2029.
• [26] BALTAKYS K., ŠIAUČIŪNAS R., BALTUŠNIKAS A., Chem. Techn., 1 (2004), 45.
• [27] CHEARY R.W., COELHO A.A., Programs XFIT and FOURYA, deposited in CCP14 Powder Diffraction Library, Engineering and Physical Sciences Research Council, Daresbury Laboratory, Warrington, England, (1996), (http://www.ccp14.ac.uk/tutorial/xfit-95/xfit.htm).
• [28] YU P., KIRKPATRICK R.J., POE B., MCMILLAN P.F., CONG X., J. Am. Ceram. Soc., 82, (1999), 724.
• [29] GARBEV K., Ph.D. Thesis, Faculty of Geology and Geography, St. Kliment Ohridski University, Sofia, 2004.