The sintering degree evaluation results were consistent with the ash fusion tests.
The severe barley husk ash sintering was mitigated with both kaolin and calcite addition. The barley husk
ash-additive mixtures retained partial brittle structures even after heated at 900 °C, and only a small
amount of ash melts was observed. For the barley straw ash, the additives also showed positive effects on
the melting and sintering behaviors of the ash. Upon kaolin addition, the initial melting temperature of the
barley straw ash was increased from 960 °C to 1150 °C.