Hydrated aluminium sulfate precipitation by enzyme-catalysed urea decomposition
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY, cilt.20, sa.6, ss.689-694, 2000 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 20 Sayı: 6
- Basım Tarihi: 2000
- Doi Numarası: 10.1016/s0955-2219(99)00202-2
- Dergi Adı: JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Sayfa Sayıları: ss.689-694
- Anahtar Kelimeler: Al2O3, powders-chemical preparation, sintering, urea, THERMAL-DECOMPOSITION
- Anadolu Üniversitesi Adresli: Hayır
Özet
Hydrated basic aluminium hydroxide precipitates were obtained from aluminium sulphate solution at room temperature and at 92 degrees C by using urea. Enzyme urease was used to decompose urea at room temperature. It was observed that precipitates obtained at room temperature were much finer than those obtained at 92 degrees C but they had similar chemistry. On calcination at 1200 degrees C, each precipitate obtained at room temperature converted to a discrete alpha-Al2O3 crystal whereas that obtained at 92 degrees C converted to a rather densely packed agglomerate of alpha-Al2O3 crystals. As a result of this, alpha-Al2O3 powder obtained from 25 degrees C precipitates showed much better sintering behaviour. (C) 2000 Elsevier Science Ltd. All rights reserved.