On the nature of phase conversions and transformations in porous system in hydrothermal processing of χ-Al2O3 into boehmite
详细信息 查看全文
- 作者：S. R. Egorova ; G. E. Bekmukhamedov…
- 刊名：Russian Journal of Applied Chemistry
- 出版年：2016
- 出版时间：May 2016
- 年：2016
- 卷：89
- 期：5
- 页码：703-713
- 全文大小：1,163 KB
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Chemistry
Chemistry
Industrial Chemistry and Chemical Engineering
Russian Library of Science - 出版者：MAIK Nauka/Interperiodica distributed exclusively by Springer Science+Business Media LLC.
- ISSN：1608-3296
- 卷排序：89
文摘
Study of the influence exerted by conditions of hydrothermal treatment of χ-Al2O3 on the phase composition and porous system parameters of the resulting products at T = 150–200°C and P = 0.5–1.5 MPa demonstrated the products formed in hydrothermal treatment of χ-Al2O3 are the bayerite and boehmite phases formed simultaneously in parallel pathways. Bayerite crystals have a needle-like shape and length of about 10 nm. 3D boehmite crystals are formed as parallelepipeds with edge size exceeding 200 nm in an alkaline medium at pH 8.0–9.2 and as 2D particles having the shape of rhombic plates with edge size of 80–500 nm and thickness of 20–100 nm at Ph 4.0–6.0. The crystallization of coarse boehmite particles favors formation of coarse mesopores and a low-porous system. A full phase transition of χ-Al2O3 to boehmite occurs at 180–200°C in 180–240 min.Original Russian Text © S.R. Egorova, G.E. Bekmukhamedov, A.N. Mukhamed’yarova, A.A. Lamberov, 2016, published in Zhurnal Prikladnoi Khimii, 2016, Vol. 89, No. 5, pp. 566-576.