ISSN 0004-881X

The Carbothermal Reduction of Zircon to Zirconia and Silicon Carbide for Ceramics and Refractories

by N. Rigopoulos¹, A. Oh¹, M. Yousuff¹, R.G. O'Donnell¹ and M.B. Trigg^1,2

1) CSIRO Materials Science and Engineering, Australia
2) Advanced Manufacturing CRC, Belmont, Australia

Abstract

The carbothermal reduction of zircon to zirconia and silicon carbide has been trialled over a range of reaction temperatures and dwell times. Low cost zircon and brown coal precursors are investigated for this reaction. The reduction reaction runs to near completion after 5hours at 1500 degC (96.6% complete) successfully producing both zirconia and silicon carbide reaction products. Temperatures and durations exceeding these, whilst reacting more of the zircon, promote the reduction of the zirconia product to zirconium carbide, with 19 wt% zirconium carbide produced following 5hours at 1600 degC. Both X-ray diffraction (XRD) and nuclear magnetic resonance (NMR) techniques are used to determine the extent of the reaction and to characterise the reaction products.

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