Chapter 4. Controlling the Setting Rate in Phosphate-Bonded Spinel Systems

  1. William J. Smothers
  1. Alan Cisar

Published Online: 26 MAR 2008

DOI: 10.1002/9780470320372.ch4

Application of Refractories: Ceramic Engineering and Science Proceedings, Volume 8, Issue 1/2

Application of Refractories: Ceramic Engineering and Science Proceedings, Volume 8, Issue 1/2

How to Cite

Cisar, A. (1987) Controlling the Setting Rate in Phosphate-Bonded Spinel Systems, in Application of Refractories: Ceramic Engineering and Science Proceedings, Volume 8, Issue 1/2 (ed W. J. Smothers), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470320372.ch4

Author Information

  1. Dow Chemical Co., Bldg. B-1402 Freeport, TX 77541

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1987

ISBN Information

Print ISBN: 9780470374702

Online ISBN: 9780470320372

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Keywords:

  • phosphate;
  • spinel systems;
  • aluminum phosphate;
  • monaluminum phosphate;
  • aluminum oxide

Summary

It has been demonstrated that specially tailored magnesium aluminum oxide spinel produced by coprecipitation and controlled firing is an excellent component in phosphate-bonded systems. The same tailoring allows the production of a composite with a controlled excess of MgO present in such a form that it is evenly and fully dispersed throughout. By using this composite for a portion of the bond phase, systems with shelf lives of several mo can be reproduclbly made to set-up in times ranging from s to d. In the pure spinel monoahtminum phosphate system an amorphous aluminum phosphate is formed on initial setting. During curing, this is first converted to Al(PO3)3, then AlPO4. If MgO is present, this sequence is altered with Mg3(PO4)2 being observed at certain temperatures. The chemistry and kinetics of these systems during setting and subsequent curing are described and applications given.