Primary slurry used for steel casting was slip cast into
20 × 80 mm rectangular bars. The formulation of primary slurry is
shown in Table 1.These bars were then dried and sintered at 1650 ◦C
for 2 h, with a ramp rate of 10 ◦C min−1. X-ray diffraction (XRD)
was carried out after the sintering process to confirm no dissociation
of zircon had occurred (Fig. 2). Pavlik and Holland (2001)
have shown that zircon converts to zirconia and silica at 1676 ◦C.
The high sintering temperature was selected to allow full densifi-