Hydrated aluminium sulfate precipitation by enzyme-catalysed urea decomposition

Kara F., Sahin G.

JOURNAL OF THE EUROPEAN CERAMIC SOCIETY, cilt.20, sa.6, ss.689-694, 2000 (SCI-Expanded) identifier identifier identifier

  • 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.