K. A. Mishagin, E. M. Gotlib, E.S. Yamaleeva, E. S. Yamaleeva, and V. S. Dutova

PHASE TRANSFORMATIONS IN THE PRODUCTION OF CALCIUM SILICATE FROM ZEOLITE-SILICA ROCK

Phase transformations in the zeolite-containing rock – calcite system during the synthesis of wollastonite in a temperature range of 800 to 1200 °C are studied. The components were mixed in a CaO/SiO2 ratio of 0.7, and then, in order to increase the contact area of the phases, grinding was performed in a Fritsch Pulverisette 5/2 planetary mill for 5 min at 200 rpm. Solid-phase synthesis was carried out in SNOL 1100/7.2 and Nabertherm LH 120/13 muffle furnaces at temperatures ranging from 800 to 1200 °C with intervals of 50 °C and an isothermal holding time of 1 to 4 h. The phase composition of the component firing products is quantitatively evaluated by quantitative X-ray analysis. The process of wollastonite formation proves to begin at temperatures ranging between 800 and 900 °C. A smooth growth of calcium metasilicate content continues up to 1100 °C, and wollastonite becomes the main product at this temperature. The maximum yield of wollastonite (81%) is reached at 1175 °C isothermal holding for 3 hours. The temperature of phase transition from β- to α-wollastonite has been experimentally found to be 1190 °C.

References:

1. Akatyeva, L.V. Razvitie khimiko-tekhnologicheskikh osnov protsessov pererabotki syria dlya polucheniya silikatov kaltsiya i kompositsionnykh materialov [Development of the Chemical and Technological Foundations of Raw Materials Processing for the Production of Calcium Silicates and Composite Materials: Doctoral Thesis]. Moscow, 2014, 328 p. (In Russian).
2. Belyankin, D.S., Lapin, V.V., and Toropov, N.A. Fiziko-khimicheskie sistemy silikatnoy tekhnologii [Physicochemical Systems of Silicate Technology]. Promstroiizdat Publ., Moscow, 1954, 372 p. (In Russian).
3. Islamova, G.G. Tekhnologiya sinteticheskogo vollastonita iz prirodnykh kaltsyi- i kremniysoderzhashchikh soedineniy [Technology of Synthetic Wollastonite Derived from Natural Calcium- and Silicon-Containing Compounds: Synopsis of Candidate Thesis]. Kazan, 2012, 20 p. (In Russian).
4. Kukolev, G.V. Khimiya kremniya i fizicheskaya khimiya silikatov [Chemistry of Silicium and Physical Chemistry of Silicates]. Vysshaya Shkola Publ., Moscow, 1966, 463 p. (In Russian).
5. Mishagin, K.A., Tverdov, I.D., Gotlib, E.M., Yamaleeva, E.S., and Khatsrinov, A.I. Research of natural domestic raw materials for the production of silicate fillers. Yuzhno-Sibirskiy Nauchnyi Vestnik, 2022, 3 (43), 67–73. (In Russian).
6. Emrullahoğlu, S.B., Emrullahoğlu, C.B., and Emrullahoğlu, Ö.F. Syntetic wollastonite production from raw and tailing materials. Key Engineering Materials, 2004, 264–268, 2485–2488. DOI: 10.4028/www.scientific.net/KEM.264-268.2485.
7. Islamova, G.G., Lygina, T.Z., and Gubajdullina, A.M. Researches of kinetics and mechanism of solid-phase synthesis of calcium silicates. In: XVII International Conference on Chemical Thermodynamics in Russia, Kazan, Russian Federation, June 29–July 3, 2009: Abstracts in Two Volums, Kazan, 2009, pp. 391.
8. Kartal, A. and Akpinar, S. Synthesis of wollastonite by using various raw materials. Key Engineering Materials, 2004, 264–268, 2469–2472. DOI: 10.4028/www.scientific.net/kem.264-268.2469.

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