The resulting powder was used to form test pieces by uniaxial
pressing. Pressing moisture content was 5.5 kg water/kg solid,
and the applied pressure was 40 MPa. The samples were dried
in an oven at 110 ◦C before testing. Their bulk density was then
determined by the mercury displacement method. The test pieces
were subsequently fired in an electric laboratory kiln at different
peak temperatures (ranging from 1140 to 1260 ◦C), with a