Study of the Kinetic Aspects of Formation of Calcium
Monosilicate in the Model System CaSO
P. S. Gordienko, A. P. Suponina, S. B. Yarusova,
S. B. Bulanova, G. F. Krysenko, and V. A. Kolzunov
Institute of Chemistry, Russian Academy of Sciences, Far Eastern Division, Vladivostok, Russia
Received October 8, 2008
Abstract—The possibility and kinetic aspects of formation of X-ray amorphous calcium monosilicate in the
model system CaSO
at room temperature were studied.
INORGANIC SYNTHESIS AND INDUSTRIAL
ISSN 1070-4272, Russian Journal of Applied Chemistry, 2009, Vol. 82, No. 9, pp. 1505–1509. © Pleiades Publishing, Ltd., 2009.
Original Russian Text © P.S. Gordienko, A.P. Suponina, S.B. Yarusova, S.B. Bulanova, G.F. Krysenko, V.A. Kolzunov, 2009, published in Zhurnal
Prikladnoi Khimii, 2009, Vol. 82, No. 9, pp. 1409–1413.
Owing to valuable physicochemical, physico-
mechanical, and thermal properties, xonotlite and
wollastonite, belonging to calcium monosilicates, are
widely used in various industrial areas .
Borogypsum waste formed in preparation of boric
acid from datolite concentrate, containing anhydrous,
semi-hydrated, and dihydrated gypsum as well as
amorphous silica, is used as a raw material for xono-
tlite and wollastonite synthesis.
It was of interest to study the kinetic aspects of
synthesis of calcium monosilicates from borogypsum
This study is concerned with the kinetics of forma-
tion of silicates in the model system CaSO
The components for synthesis of calcium mono-
silicates, anhydrous gypsum (10 g) and liquid glass
(pure grade, silicate modulus SiO
O = 1), were
mixed at a stoichiometric ratio 1:1 in aqueous medium.
The synthesis was performed in an UM-1
UNITRA–UNIMA water bath (LABIMEX, Poland)
ensuring ultrasonic treatment of the reaction mixture in
air at room temperature for a certain time, 0.5, 1.0, 3.0,
5.0, and 7.0 h. The volume of the water bath was
and its dimensions were 120×120×100 mm.
Additionally, a 48-h synthesis with mixing of the
reaction mixture with a magnetic stirrer was per-
formed. As was established previously, it is reasonable
to synthesize calcium monosilicate in an ultrasonic
The precipitate was separated from the solution by
filtration onto a paper white tape with a water-jet pump
and washed 2–3 times with distilled water warmed to
boiling temperature, at which the solubility of gypsum
in water is minimal (0.1619 g/100 g) . Under these
conditions, the additional amount of sulfate ions
passed into the solution is small and contributes
negligibly into the total amount of sulfate ions present
in the aqueous phase of the mixture after the synthesis.
A solution containing 4.0 mg ml
chloride was prepared by dissolving a precise weighed
portion of chemical purity grade barium chloride in
The barium content was determined by flame
atomic absorption spectroscopy [(АА-780 “Nippon
Jarrell Ash” spectrometer, 535-nm line, acetylene-air
The reaction was monitored by the X-ray phase and
IR spectroscopic analyses of deposits dried at room
temperature. The deposits annealed at 850 and 1000°C
for 1 h were also analyzed by the same methods.
The diffraction patterns of the deposits were
recorded on a D8 ADVANCE automated diffracto-