The sintering behaviors of the barley husk ash agreed with
the ash fusion temperature determination results. Already at 800 °C, the barley husk ash sintered and
covered by shiny glassy materials, which corresponds to sintering degree 3. The barley husk ash melted
completely after heated at 1000 °C and partially formed as slag that shrunk into droplets on the bottom of
the crucibles. Different from the barley husk ash, the barley straw ash has a higher initial melting
temperature of approximately 950 °C.