Effects of quartz particle size and water-to-solid ratio on hydrothermal synthesis of tobermorite studied by in-situ time-resolved X-ray diffraction

Journal Article · Mon Aug 15 00:00:00 EDT 2011 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2011.05.061· OSTI ID:21580219

Kikuma, J ^[1]; Tsunashima, M; Ishikawa, T; Matsuno, S ^[1]; Ogawa, A; Matsui, K ^[2]; Sato, M ^[3]

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1. Analysis and Simulation Center, Asahi-KASEI Corporation, 2-1 Samejima Fuji, Shizuoka 416-8501 (Japan)
2. Construction Materials Laboratory, Asahi-KASEI Construction Materials Corporation, Sakai-machi, Ibaraki 306-0493 (Japan)
3. Industrial Application Division, SPring-8/JASRI, Sayo, Hyogo 679-5198 (Japan)

Hydrothermal synthesis process of tobermorite (5CaO.6SiO{sub 2}.5H{sub 2}O) has been investigated by in-situ X-ray diffraction using high-energy X-rays from a synchrotron radiation source in combination with a purpose-build autoclave cell. Dissolution rates of quartz were largely affected by its particle size distribution in the starting mixtures. However, the composition (Ca/Si) of non-crystalline C-S-H at the start of tobermorite formation was identical regardless of the quartz dissolution rate. An effect of water-to-solid ratio (w/s) was investigated for samples using fine particle quartz. Tobermorite did not occur with w/s of 1.7 but occurred with w/s higher than 3.0. Surprisingly, however, the dissolution curves of quartz were nearly identical for all samples with w/s from 1.7 to 9, indicating that the dissolution rate is predominated by surface area. Possible reaction mechanism for tobermorite formation will be discussed in terms of Ca and/or silicate ion concentration in the liquid phase and distribution of Ca/Si in non-crystalline C-S-H. - Graphical abstract: Time-resolved XRD data set was obtained at up to 190 deg. C under a saturated steam pressure. Tobermorite (5CaO.6SiO{sub 2}.5H{sub 2}O) formation reaction was investigated in detail for several different starting materials. Highlights: > Hydrothermal formation of tobermorite was monitored by in-situ XRD. > Ca/Si of C-S-H at the start time of tobermorite formation was determined. > The Ca/Si value was identical regardless of the quartz particle size in the starting mixture.

• OSTI ID: 21580219
• Journal Information: Journal of Solid State Chemistry, Vol. 184, Issue 8; Other Information: DOI: 10.1016/j.jssc.2011.05.061; PII: S0022-4596(11)00310-0; Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
DISSOLUTION
HYDROTHERMAL SYNTHESIS
PARTICLE SIZE
PARTICLES
QUARTZ
REACTION KINETICS
SILICATES
SOLIDS
SYNCHROTRON RADIATION SOURCES
TIME RESOLUTION
X RADIATION
X-RAY DIFFRACTION
COHERENT SCATTERING
DIFFRACTION
ELECTROMAGNETIC RADIATION
IONIZING RADIATIONS
KINETICS
MINERALS
OXIDE MINERALS
OXYGEN COMPOUNDS
RADIATION SOURCES
RADIATIONS
RESOLUTION
SCATTERING
SILICON COMPOUNDS
SIZE
SYNTHESIS
TIMING PROPERTIES